Charging and storage system and charging pile

Abstract

The invention discloses a charging and storage system and a charging pile, the charging and storage system comprises a charging device, the charging device comprises an energy storage module, the energy storage module comprises one or more energy storage units, each energy storage unit is provided with a first positive power supply end and a first negative power supply end, the one or more energy storage units are connected with a second positive power supply end and a second negative power supply end of the energy storage module through a first positive power supply end and a first negative power supply end, and the energy storage module is configured to provide first direct current; the charging module is connected with the second positive power supply end and the second negative power supply end of the energy storage module, the charging module is configured to be suitable for charging output based on the first direct current, the maximum charging output power of the charging module is larger than or equal to 350 kilowatts, and / or the rated charging output power of the charging module is larger than or equal to 290 kilowatts. Therefore, the energy storage unit is arranged in the charging device, so that high-power charging, such as overcharging / fast charging, can be realized, and the cost is low.

Description

[0001] Cross - reference to related applications This application claims priority to the following patent applications, the entire contents of which are incorporated herein by reference: PCT International Patent Application No. PCT / CN2024 / 093513, titled "Charging Device, Charging Pile and Charging and Energy Storage System", filed on May 15, 2024; PCT International Patent Application No. PCT / CN2024 / 102652, titled "Battery Cell, Battery and Electrical Device", filed on June 28, 2024. Technical Field

[0002] This application relates to the field of charging technologies, and particularly to a charging and energy storage system and a charging pile. Background Art

[0003] Currently, fast charging / ultra-fast charging piles are less applied. However, with the popularization of fast charging / ultra-fast charging electric vehicles, a large number of fast charging / ultra-fast charging piles are urgently needed.

[0004] However, fast charging / ultra-fast charging piles in related technologies all require additional configuration of a transformer or transformer capacity expansion, which is not conducive to the rapid access of fast charging / ultra-fast charging piles and will increase more costs. Summary of the Invention

[0005] In view of the above problems, this application provides a charging and energy storage system and a charging pile. Without the need for additional configuration of a transformer or transformer capacity expansion, by configuring an energy storage unit inside the charging device, not only can fast charging of the charging device be achieved, such as fast charging / ultra-fast charging, but also the costs brought by adding a new transformer or expanding the transformer capacity can be reduced.

[0006] In a first aspect, the present application provides a charging and storage system, including a charging device. The charging device includes: a energy storage module, which includes one or more energy storage units. Each energy storage unit has a first positive power terminal and a first negative power terminal. The one or more energy storage units are connected to a second positive power terminal and a second negative power terminal of the energy storage module through the first positive power terminal and the first negative power terminal. The energy storage module is configured to provide a first direct current; an input module, which is adapted to provide charging energy for each energy storage unit; a charging module, which is connected to the second positive power terminal and the second negative power terminal of the energy storage module. The charging module is configured to be adapted to perform charging output based on the first direct current. The maximum charging output power of the charging module is greater than or equal to 350 kilowatts, and / or the rated charging output power of the charging module is greater than or equal to 290 kilowatts. The ratio between the maximum charging output power of the charging module and the maximum output power of the input module is greater than 1 and less than or equal to 15, and / or the ratio between the rated charging output power of the charging module and the rated output power of the input module is greater than 1 and less than or equal to 15. When the number of energy storage units is multiple, the energy storage units and the charging module are configured to be able to charge an electrical device with different output powers.

[0007] In the technical solution of the embodiment of the present application, without the need to additionally configure a transformer or expand the transformer, by configuring energy storage units inside the charging device, not only can fast charging of the charging device be achieved, such as fast charging / ultra-fast charging, but also the cost brought by adding a new transformer or expanding the transformer can be reduced.

[0008] The input module can be adapted to provide charging energy for the energy storage unit. In different power usage environments, whether it is an old urban area with relatively tight power supply or a remote area sensitive to the cost of infrastructure construction, the charging device, relying on the cooperation of the input module and the energy storage module, can achieve the fast charging function without relying on complex external power supply upgrades, enhancing the applicability and flexibility of the charging device in various scenarios.

[0009] In some embodiments, each energy storage unit includes a battery subunit. The ratio between the rated output power of the input module and the rated energy of the battery subunit is greater than or equal to 1 / n1, where the value range of n1 is 1 to 4.

[0010] Thus, when the input power is low and the output power is high, the battery sub-units can charge the electrical device at different charging rates, so as to adjust the charging rate according to the charging requirements of the electrical device during the charging process or different charging time periods, enabling the charging device to reasonably utilize the electric energy stored in itself to charge the electrical device, effectively utilizing the energy stored in the charging device, improving the cost performance of the entire charging device, and enhancing the working stability of the charging device. During different charging processes, the charging device plays a "buffering" role between the power grid and the electrical device, reducing the impact on the power grid caused by high-power output.

[0011] In some embodiments, each energy storage unit includes a battery sub-unit, and the ratio between the rated energy of the battery sub-unit and the rated charging output power of the charging module is greater than or equal to 1 / (n2*n3), where the value range of n2 is 94% - 99%, and the value range of n3 is 4 - 6.

[0012] Thus, while ensuring the charging performance, the reliability of the charging device is also taken into account. When the rated energy of the battery sub-unit matches the rated charging output power of the charging module, during the charging process, the battery sub-unit can stably supply energy to the charging module, reducing the instability or interruption of the charging power caused by insufficient energy supply. Taking n2 = 94% and n3 = 6 as an example, the relatively large denominator requires the battery sub-unit to have a relatively high rated energy to match the power of the charging module. This enables the charging device to work continuously and stably during long-time and high-power charging processes, reducing the probability of failures, lowering the maintenance cost, and improving the cost performance in terms of the service life of the charging device.

[0013] In some embodiments, each energy storage unit includes a battery sub-unit, the ratio between the rated energy of the battery sub-unit and the rated power of the battery sub-unit is less than or equal to 1 / 3, and / or the volumetric energy density of the battery sub-unit is greater than or equal to 380 Wh / L.

[0014] When the charging device outputs high power (the maximum charging output power of the charging module is above 350 kW), matching the rated energy and the rated power of the battery sub-unit reduces the grid fluctuations caused by the insufficient rated energy of the battery sub-unit due to high-power output and the need for power grid power supply, which is beneficial to improving the reliability and stability of the charging device. Moreover, when outputting high power, the charging device can work continuously and stably, reducing the probability of failures, lowering the maintenance cost, and improving the cost performance in terms of the service life of the charging device.

[0015] In some embodiments, each energy storage unit includes a battery sub-unit, the battery sub-unit includes single-cell battery cores, the single-cell battery cores include electrolytes, the electrolytes include electrolyte salts, the electrolyte salts include lithium hexafluorophosphate, and the concentration of lithium hexafluorophosphate is in the range of 0.5 mol / L - 1.0 mol / L.

[0016] By setting the electrolyte to include lithium hexafluorophosphate at the above concentration, the battery subunit has a high ionic conductivity, thereby improving the charging rate of the charging device. Moreover, the battery subunit also has high interfacial stability and high thermal stability; lithium hexafluorophosphate has little influence on the severity of thermal runaway, enabling the battery subunit to have an appropriate severity of thermal runaway and a low risk of thermal diffusion, so that the charging device has high reliability when the power output is above 350 kW.

[0017] In some embodiments, the electrolyte further includes an organic solvent, and the organic solvent includes a carbonate solvent.

[0018] Adding a carbonate solvent to the electrolyte can improve various performances of the battery subunit. For example, it can improve the charge-discharge efficiency, cycle performance, low-temperature performance, and high-voltage stability of the battery subunit.

[0019] In some embodiments, the electrolyte salt further includes a fluorosulfonylimide salt, and the concentration of the fluorosulfonylimide salt is in the range of 0.2 mol / L - 0.5 mol / L.

[0020] Due to the characteristics of the fluorosulfonylimide salt having a low viscosity and high ionic conductivity, the electrolyte including the fluorosulfonylimide salt at the above concentration is beneficial to improving the charging rate of the battery subunit, and thus improving the charging rate of the charging device.

[0021] In some embodiments, the electrolyte further includes an organic solvent, and the organic solvent includes a chain carboxylic ester solvent. Based on the total mass of the solvent, the mass content A of the chain carboxylic ester solvent satisfies: 5% ≤ A ≤ 75%. Among them, the chain carboxylic ester solvent includes a compound having the following structure:

[0022] Among them, R1 includes at least one of a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 haloalkyl group, and R2 includes a C1-C5 alkyl group and / or a C1-C5 haloalkyl group.

[0023] In this technical solution, the solvent includes a carboxylic ester solvent. In this way, the electrolyte can have a higher ionic conductivity and a relatively low viscosity, which is beneficial to further improving the fast charging performance of the charging device, such as fast charging performance and / or ultra-fast charging performance.

[0024] In some embodiments, 40% ≤ A ≤ 75%.

[0025] Setting A to be greater than or equal to 40% and less than or equal to 75% can better achieve the purpose of fast charging of the charging device.

[0026] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes single cell cores, the single cell cores include negative electrode plates, the negative electrode plates include negative electrode current collectors and negative electrode film layers disposed on at least one side of the negative electrode current collectors, the negative electrode film layers include negative electrode active materials, the negative electrode active materials include carbon-based materials, and the carbon-based materials include at least one of natural graphite and artificial graphite.

[0027] Using at least one of natural graphite and artificial graphite as the carbon-based material of the negative electrode active material, the two have good electrical conductivity and high theoretical specific capacity. Natural graphite has high crystallinity and regular layered structure, which is beneficial to the rapid insertion and extraction of lithium ions, thereby improving the charge and discharge efficiency of the battery; artificial graphite can precisely adjust its microstructure and performance by controlling the production process, enhance the cycle stability of the battery, and extend the service life of the battery.

[0028] In some embodiments, the volume average particle size Dv50 of the negative electrode film layer is in the range of 8.2 μm - 13.5 μm.

[0029] Thus, this particle size range can balance the specific surface area and tap density. Smaller particle sizes can provide a larger specific surface area, increase the reaction sites of lithium ions, and improve the charge and discharge rate performance of the battery; while appropriate particle sizes can ensure a higher tap density, reduce the voids between active substances, and improve the energy density of the battery, so that the battery can achieve a better balance in rate performance and energy density.

[0030] In some embodiments, the negative electrode film layer includes a first negative electrode active material layer and a second negative electrode active material layer stacked, the first negative electrode active material layer is located on the side close to the negative electrode current collector, the volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer is 9.5 μm - 18.5 μm, and the volume average particle size Dv50 of the negative electrode active material in the second negative electrode active material layer is 7.8 μm - 14.3 μm.

[0031] When the volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer and the volume average particle size Dv50 of the negative electrode active material in the second negative electrode active material layer are in the above ranges, on the one hand, it can shorten the solid-phase transmission path of lithium ions and improve the fast charging performance. On the other hand, the materials are not easily agglomerated during the preparation process, which can improve the stability of the materials. The cooperation of the negative electrode active material in the second negative electrode active material layer and the negative electrode active material in the first negative electrode active material layer within the above volume average particle size range is beneficial to constructing the gradient pore difference between the second negative electrode active material layer and the first negative electrode active material layer, reducing the tortuosity of lithium ion transmission, and improving the fast charging performance of the battery cell.

[0032] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a single cell, the single cell includes a negative electrode tab, the negative electrode tab includes a negative current collector and at least a negative film layer on one side of the negative current collector, and the negative film layer includes a negative active material layer.

[0033] When the single cell is in a 100% charged state, the compaction density of the negative film layer is 1.15 g / cm 3 -1.36 g / cm 3 , and / or, the single-sided coating weight of the negative film layer is 0.09 g / 1540.25 mm 2 -0.17 g / 1540.25 mm 2 .

[0034] When the compaction density of the negative film layer is within the above range, it is beneficial to improve the energy density of the battery cell. And because the negative active materials in the negative film layer are stacked relatively tightly, the contact resistance between particles is small, which can further reduce the resistance of the electrode tab, thereby reducing heat generation. When the single-sided coating weight of the negative film layer is within the above range, the heat generation per unit area of the negative electrode tab will not be too large, and it can also take into account the improvement of the energy density of the battery cell.

[0035] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a single cell, the single cell includes a positive electrode tab, the positive electrode tab includes a positive current collector and at least a positive film layer on one side of the positive current collector, and the positive film layer includes a positive active material layer; When the single cell is in a 100% charged state, the compaction density of the positive film layer is 2.5 g / cm 3 -2.8 g / cm 3 .

[0036] When the compaction density of the positive film layer is within the above range, it is beneficial to improve the energy density of the battery cell. And because the positive active materials in the positive film layer are stacked relatively tightly, the contact resistance between particles is small, which can further reduce the resistance of the electrode tab, thereby reducing heat generation.

[0037] In some embodiments, the single-sided coating weight of the positive film layer is 0.2 g / 1540.25 mm 2 -0.37 g / 1540.25 mm 2 .

[0038] When the single-sided coating weight of the positive film layer is within the above range, the heat generation per unit area of the positive electrode tab will not be too large, and it can also take into account the improvement of the energy density of the battery cell.

[0039] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a single cell, the single cell includes a positive electrode tab, the positive electrode tab includes a positive electrode current collector and a positive electrode film layer located at least on one side of the positive electrode current collector, and the thickness of the positive electrode current collector is 10 μm - 15 μm.

[0040] When the thickness of the positive electrode current collector is within the above range, the current-carrying capacity of the positive electrode current collector is relatively excellent, and the battery cell can have a high energy density.

[0041] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a single cell, the single cell includes a separator, the separator includes a base film with a porous structure, and the porosity of the base film is 20% to 70%.

[0042] When the porosity of the base film is within the above range, the migration ability of lithium ions in the separator can be improved, the internal resistance of the battery cell can be reduced, and thus heat generation can be reduced.

[0043] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a positive electrode tab, the positive electrode tab includes a positive electrode current collector and a positive electrode film layer provided on at least one side of the positive electrode current collector, the positive electrode film layer includes a positive electrode active material, and the positive electrode active material includes a lithium-containing phosphate; Wherein, the lithium-containing phosphate includes phosphate particles and a coating layer, the coating layer coats at least part of the surface of the phosphate particles, and the coating layer includes one or more elements of C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0044] Under this technical solution, the positive electrode coating layer has excellent ion-conducting and electron-conducting abilities, can improve the ionic conductivity and electronic conductivity of the positive electrode active material, thereby effectively improving the charging rate of the battery subunit, improving the fast charging performance of the charging device, and being beneficial to improving the fast charging performance of the battery device.

[0045] In some embodiments, the coating layer includes a fast ion conductor, wherein the fast ion conductor includes a compound with the general formula Li 3-d Fe 2- d M 2d (PO4)3, M2 includes at least one element of Ti, Zr, Hf, Ge, and Sn, and 0 ≤ d ≤ 1.

[0046] Since the fast ion conductor has a high ionic conductivity, which is beneficial to the diffusion and transmission of lithium ions, thus, the charging rate of the battery subunit can be further improved, the fast charging performance of the charging device can be improved, and it is beneficial to improving the fast charging performance of the battery device.

[0047] In some embodiments, each energy storage unit includes a battery subunit, and the battery subunit includes a positive electrode tab. The positive electrode tab includes a positive current collector, a positive conductive layer, and a positive electrode film layer. The positive electrode film layer is disposed on at least one side of the positive current collector, the positive conductive layer is located between the positive current collector and the positive electrode film layer, and the thickness of the positive conductive layer is in the range of 0.5 μm - 2 μm.

[0048] In this way, the diffusion path of lithium ions can be shortened, thereby improving the rate performance of the battery subunit, which is beneficial to enhancing the fast charging performance of the battery device.

[0049] In some embodiments, the positive conductive layer includes a positive conductive agent, and based on the total mass of the positive conductive layer, the mass content of the positive conductive agent is in the range of 30% - 50%.

[0050] In this technical solution, by setting the mass content of the positive conductive agent in the range of 30% - 50%, the electron transfer efficiency in the positive electrode tab can be improved, and thus the rate performance of the battery subunit can be enhanced.

[0051] In some embodiments, the positive conductive layer includes a positive binder, and based on the total mass of the positive conductive layer, the mass content of the positive binder is in the range of 50% - 70%.

[0052] In this technical solution, by setting the mass content of the positive binder in the range of 50% - 70%, the possibility of cracking or peeling of the positive electrode tab during cycling can be reduced, and thus the cycle life of the battery subunit can be improved.

[0053] In some embodiments, each energy storage unit includes a battery subunit, and the battery subunit includes a negative electrode tab. The negative electrode tab includes a negative current collector, a negative conductive layer, and a negative electrode film layer. The negative electrode film layer is disposed on at least one side of the negative current collector, the negative conductive layer is located between the negative current collector and the negative electrode film layer, and the thickness of the negative conductive layer is in the range of 0.5 μm - 2 μm.

[0054] In this way, the diffusion path of lithium ions can be shortened, thereby improving the rate performance of the battery subunit, which is beneficial to enhancing the fast charging performance of the battery device.

[0055] In some embodiments, the negative conductive layer includes a negative conductive agent, and based on the total mass of the negative conductive layer, the mass content of the negative conductive agent is in the range of 20% - 40%.

[0056] In this technical solution, by setting the mass content of the negative conductive agent in the range of 20% - 40%, the electron transfer efficiency in the negative electrode tab can be improved, and thus the rate performance of the battery subunit can be enhanced, which is beneficial to enhancing the fast charging performance of the battery device.

[0057] In some embodiments, the negative electrode conductive layer includes a negative electrode binder, and based on the total mass of the negative electrode conductive layer, the mass content of the negative electrode binder is in the range of 60% - 80%.

[0058] In this technical solution, setting the mass content of the negative electrode binder in the range of 60% - 80% can reduce the possibility of cracking or peeling of the negative electrode sheet during cycling, thereby improving the cycle life of the battery sub-unit and being beneficial to enhancing the cycle life of the battery device.

[0059] In some embodiments, one or more energy storage units are connected in series and / or in parallel between the second positive power supply terminal and the second negative power supply terminal of the energy storage module through the first positive power supply terminal and the first negative power supply terminal to provide a first direct current. With such a setting, the function of small-power input and large-power output of the charging and energy storage system can be satisfied, thereby improving the adaptability of the charging and energy storage system.

[0060] In some embodiments, each energy storage unit includes a battery sub-unit, and each energy storage unit is configured to provide a second direct current based on the electrical energy of the battery sub-unit.

[0061] In some embodiments, at least some of the one or more energy storage units further include a first power conversion sub-unit. The first power conversion sub-unit is respectively connected to the corresponding battery sub-unit and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit, and is configured to convert the electrical energy of the battery sub-unit into a second direct current; wherein, when the energy storage unit does not include the first power conversion sub-unit, the battery sub-unit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide a second direct current. In this way, the charging flexibility can be improved.

[0062] In some embodiments, at least some of the one or more energy storage units further include a first switch sub-unit. The first switch sub-unit is respectively connected to the corresponding battery sub-unit and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit, and is configured to connect the corresponding battery sub-unit to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit when conducting to provide a second direct current; wherein, when the energy storage unit does not include the first switch sub-unit, the battery sub-unit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide a second direct current. In this way, the energy storage unit can be protected.

[0063] In some embodiments, at least some of the one or more energy storage units further include a first power conversion subunit and a first switch subunit. The first power conversion subunit and the first switch subunit are connected in series between the corresponding battery subunit and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit. The first power conversion subunit is configured to convert the electrical energy of the battery subunit into a second direct current when the corresponding first switch subunit is turned on. Wherein, in the case that the energy storage unit does not include the first power conversion subunit and the first switch subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide a second direct current. In this way, the charging flexibility can be improved and the energy storage unit can be protected.

[0064] In some embodiments, the input module includes an input interface. The input interface is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module and is configured to provide charging energy for each energy storage unit based on the third direct current provided by the first external power supply. Alternatively, the input module includes a second power conversion subunit. The second power conversion subunit is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module and is configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply. In this way, it is possible to allow AC input or DC input to charge the energy storage unit.

[0065] In some embodiments, the charging module includes a third power conversion subunit and a charging gun. The positive input terminal and the negative input terminal of the third power conversion subunit are correspondingly connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module. The positive output terminal and the negative output terminal of the third power conversion subunit are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun. The third power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun. In this way, the charging gun does not share a negative terminal.

[0066] In some embodiments, the charging module includes a fourth power conversion subunit and a charging gun. The positive input terminal of the fourth power conversion subunit is connected to the second positive power supply terminal of the energy storage module. The positive output terminal of the fourth power conversion subunit is connected to the positive input terminal of the charging gun. The negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The fourth power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun. In this way, the charging gun shares a negative terminal, which can reduce costs.

[0067] In some embodiments, the energy storage module further includes a selection unit. The selection unit is connected to one or more energy storage units and is configured to select at least one energy storage unit from the one or more energy storage units to be connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module to provide a first direct current. In this way, the charging flexibility can be improved.

[0068] In some embodiments, there is one second positive power supply terminal and one second negative power supply terminal of the energy storage module. The selection unit includes a plurality of second switch sub-units, each second switch sub-unit is connected to an energy storage unit, each second switch sub-unit is connected in series between the first positive power supply terminal of the corresponding energy storage unit and the second positive power supply terminal of the energy storage module, the first negative power supply terminals of one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module, and the second switch sub-unit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the second positive power supply terminal of the energy storage module when turned on.

[0069] In some embodiments, the charging module includes a fifth power conversion sub-unit and a charging gun. The positive input terminal and the negative input terminal of the fifth power conversion sub-unit are correspondingly connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, the positive output terminal and the negative output terminal of the fifth power conversion sub-unit are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun, and the fifth power conversion sub-unit is configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun does not share a common negative terminal.

[0070] In some embodiments, the charging module includes a sixth power conversion sub-unit and a charging gun. The positive input terminal of the sixth power conversion sub-unit is connected to the second positive power supply terminal of the energy storage module, the positive output terminal of the sixth power conversion sub-unit is connected to the positive input terminal of the charging gun, the negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module, and the sixth power conversion sub-unit is configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun shares a common negative terminal, which can reduce costs.

[0071] In some embodiments, there are multiple second positive power supply terminals of the energy storage module and one second negative power supply terminal of the energy storage module. The selection unit includes a plurality of second switch sub-units, each second switch sub-unit is connected to an energy storage unit and a second positive power supply terminal, each second switch sub-unit is connected in series between the first positive power supply terminal of the corresponding energy storage unit and the corresponding second positive power supply terminal, the first negative power supply terminals of one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module, and the second switch sub-unit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the corresponding second positive power supply terminal when turned on.

[0072] In some embodiments, the charging module includes a plurality of seventh power conversion sub-units and a charging gun. The positive input terminal and the negative input terminal of each seventh power conversion sub-unit are correspondingly connected to a second positive power supply terminal and a second negative power supply terminal, the positive output terminal and the negative output terminal of each seventh power conversion sub-unit are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun, and the plurality of seventh power conversion sub-units are configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun does not share a common negative terminal.

[0073] In some embodiments, the charging module includes a plurality of eighth power conversion subunits and a charging gun. The positive input terminal of each eighth power conversion subunit is connected to a second positive power supply terminal, and the positive output terminal of each eighth power conversion subunit is connected to the positive input terminal of the charging gun. The negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The plurality of eighth power conversion subunits are configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun shares the negative terminal, which can reduce costs.

[0074] In some embodiments, the input module includes a ninth power conversion subunit. The ninth power conversion subunit is connected to one or more energy storage units and is configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply. In this way, the charging of the energy storage unit is achieved through one power conversion subunit.

[0075] In some embodiments, the input module includes a plurality of tenth power conversion subunits. Each tenth power conversion subunit is connected to an energy storage unit, and the plurality of tenth power conversion subunits are configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply. In this way, the charging of the energy storage unit is achieved through a plurality of power conversion subunits.

[0076] In some embodiments, when multiple charging devices share a common DC bus and the input module of the charging device includes an input interface, the system further includes: A first transformer. The primary winding of the first transformer is connected to the AC power grid and is configured to convert the second alternating current provided by the AC power grid into the first alternating current; A first AC-DC conversion module. The first AC-DC conversion module is respectively connected to the secondary winding of the first transformer and the DC bus and is configured to convert the first alternating current into the third direct current; Wherein, the second positive power supply terminal and the second negative power supply terminal of the energy storage module in multiple charging devices are both connected to the DC bus. In this way, the common DC bus of multiple charging devices is realized.

[0077] In some embodiments, when multiple charging devices share a common DC bus and the input module of the charging device includes a second power conversion subunit, the system further includes: A first transformer. The primary winding of the first transformer is connected to the AC power grid, the second power conversion subunit is respectively connected to the secondary winding of the first transformer and the DC bus, and the first transformer is configured to convert the second alternating current provided by the AC power grid into the first alternating current; Wherein, the second positive power supply terminal and the second negative power supply terminal of the energy storage module in multiple charging devices are both connected to the DC bus. In this way, the common DC bus of multiple charging devices is realized.

[0078] In some embodiments, when multiple charging devices share a common AC bus and the input module of the charging device includes a ninth power conversion subunit or multiple tenth power conversion subunits, the system further includes: A second transformer, where the primary winding of the second transformer is connected to the AC power grid, and the secondary winding of the second transformer is connected to the AC bus, and is configured to convert the second alternating current provided by the AC power grid into the first alternating current; Among them, the ninth power conversion subunit or multiple tenth power conversion subunits of the input modules in multiple charging devices are all connected to the AC bus. In this way, sharing of the common AC bus by multiple charging devices is achieved.

[0079] In some embodiments, the charging device further includes a wireless communication module, and at least part of the energy storage module, the input module, and the charging module is connected to the wireless communication module to perform information interaction with an external device through the wireless communication module.

[0080] In a second aspect, the present application provides a charging pile, including the aforementioned charging device.

[0081] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of the present application more obvious and understandable, the following specifically illustrates the specific embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And in all the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 It is a schematic structural diagram of a charging device with series-connected energy storage units according to an embodiment of the present application.

[0083] Figure 2 It is a schematic structural diagram of a charging device with an input module according to an embodiment of the present application.

[0084] Figure 3 It is a schematic structural diagram of a charging device with parallel-connected energy storage units according to an embodiment of the present application.

[0085] Figure 4a It is a schematic structural diagram of a charging device in which the energy storage unit includes a battery subunit according to an embodiment of the present application.

[0086] Figure 4b It is a schematic structural diagram of a charging device in which the energy storage unit includes a battery subunit and a first power conversion subunit according to an embodiment of the present application.

[0087] Figure 4c Schematic diagram of the charging device of the energy storage unit including the battery subunit and the first switch subunit according to an embodiment of the present application.

[0088] Figure 4d Schematic diagram of the charging device of the energy storage unit including the battery subunit, the first power conversion subunit and the first switch subunit according to an embodiment of the present application.

[0089] Figure 5a Schematic diagram of the charging device of the input module including the input interface according to an embodiment of the present application.

[0090] Figure 5b Schematic diagram of the charging device of the input module including the second power conversion subunit according to an embodiment of the present application.

[0091] Figure 6a Schematic diagram of the charging device with non - common - negative charging gun according to an embodiment of the present application.

[0092] Figure 6b Schematic diagram of the charging device with common - negative charging gun according to an embodiment of the present application.

[0093] Figure 7 Schematic diagram of the charging device with a selection unit according to an embodiment of the present application.

[0094] Figure 8 is Figure 7 Schematic diagram of the charging device shown with a second positive power supply terminal.

[0095] Figure 9a is Figure 8 Schematic diagram of the charging device shown with a second positive power supply terminal and non - common - negative charging gun.

[0096] Figure 9b is Figure 8 Schematic diagram of the charging device shown with a second positive power supply terminal and common - negative charging gun.

[0097] Figure 10 is Figure 7 Schematic diagram of the charging device shown with multiple second positive power supply terminals.

[0098] Figure 11a is Figure 10 Schematic diagram of the charging device shown with multiple second positive power supply terminals and non - common - negative charging gun.

[0099] Figure 11b is Figure 10Schematic diagram of a charging device with multiple second positive power terminals and a common negative for the charging gun.

[0100] Figure 12a For Figure 7 Schematic diagram of a charging device with a selection unit and an input module including a ninth power conversion sub-unit.

[0101] Figure 12b For Figure 7 Schematic diagram of a charging device with a selection unit and an input module including multiple tenth power conversion sub-units.

[0102] Figure 13 Schematic diagram of a charging device with a wireless communication module according to an embodiment of the present application.

[0103] Figure 14 Schematic diagram of a charging device in which energy storage units are connected in series, each energy storage unit includes a bidirectional DCDC sub-unit, and the charging guns do not share a common negative.

[0104] Figure 15 Schematic diagram of a charging device in which energy storage units are connected in series, each energy storage unit includes a bidirectional DCDC sub-unit, and the charging guns share a common negative.

[0105] Figure 16 Schematic diagram of a charging device in which energy storage units are connected in parallel, each energy storage unit includes a bidirectional DCDC sub-unit, and the charging guns do not share a common negative.

[0106] Figure 17 Schematic diagram of a charging device in which energy storage units are connected in parallel, each energy storage unit includes a bidirectional DCDC sub-unit, and the charging guns share a common negative.

[0107] Figure 18 Schematic diagram of a charging device in which energy storage units are connected in series, some energy storage units include bidirectional DCDC sub-units, and the charging guns do not share a common negative.

[0108] Figure 19 Schematic diagram of a charging device in which energy storage units are connected in series, some energy storage units include bidirectional DCDC sub-units, and the charging guns share a common negative.

[0109] Figure 20 Schematic diagram of a charging device in which energy storage units are connected in parallel, each energy storage unit includes a first switch sub-unit, and the charging guns do not share a common negative.

[0110] Figure 21Schematic diagram of a charging device in which a energy storage unit and a bidirectional ACDC sub-unit of the present application form three-phase electricity and the charging guns do not share a negative terminal.

[0111] Figure 22 Schematic diagram of a charging device in which a energy storage unit and a bidirectional ACDC sub-unit of the present application form three-phase electricity and the charging guns share a negative terminal.

[0112] Figure 23 Schematic diagram of a single cell provided by some embodiments of the present application.

[0113] Figure 24 Explosion diagram of a single cell provided by some embodiments of the present application.

[0114] Figure 25 Schematic diagram of a battery module provided by some embodiments of the present application.

[0115] Figure 26 Schematic diagram of a battery pack provided by some embodiments of the present application.

[0116] Figure 27 Schematic diagram of an electrical equipment provided by some embodiments of the present application.

[0117] Figure 28 Schematic diagram of a charging pile according to an embodiment of the present application.

[0118] Figure 29 Schematic diagram of a charging and energy storage system according to an embodiment of the present application.

[0119] Figure 30 Schematic diagram of a charging and energy storage system in which multiple charging devices share a DC bus according to an embodiment of the present application.

[0120] Figure 31 Schematic diagram of a charging and energy storage system in which multiple charging devices share a DC bus according to another embodiment of the present application.

[0121] Figure 32 Schematic diagram of a charging and energy storage system in which multiple charging devices share an AC bus according to an embodiment of the present application.

[0122] Explanation of reference numerals is as follows: 100. Charging device; 110. Energy storage module; 120. Charging module; 121. Third power conversion sub-unit; 122. Charging gun; 123. Fourth power conversion sub-unit; 124. Fifth power conversion sub-unit; 125. Sixth power conversion sub-unit; 130. Input module; 140. Wireless communication module; 111. Selection unit; 210. First external power source; 220. Second external power source; 131. Second power conversion sub-unit; 132. Ninth power conversion sub-unit; 1. Electrical equipment; 2. Battery pack; 3. Controller; 4. Motor; 5. Box body; 5a. First box body part; 5b. Second box body part; 5c. Accommodating space; 6. Battery module; 7. Single cell 10. Electrode assembly; 11. First tab; 13. Second tab; 12. Main body part; 20. Outer shell; 21. Shell; 22. End cover; 31. First electrode terminal; 32. Second electrode terminal. Detailed implementation manners

[0123] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0124] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0125] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0126] Referring to "embodiments" herein means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0127] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this text, the character " / " generally represents an "or" relationship between the associated objects before and after.

[0128] In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0129] In the description of the embodiments of the present application, for technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of the present application.

[0130] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "coupling", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0131] Currently, fast charging / supercharging charging piles are less used. However, with the popularization of fast charging / supercharging electric vehicles, a large number of fast charging / supercharging charging piles are urgently needed.

[0132] However, fast charging / supercharging charging piles in related technologies all require additional configuration of transformers or transformer capacity expansion, which is not conducive to the rapid access of fast charging / supercharging charging piles and will increase costs. For example, the input end of the transformer is connected to the AC power grid, and the output end of the transformer is connected to the charging pile. When the charging pile is a fast charging / supercharging charging pile, it is necessary to expand the capacity of the transformer or add a new transformer between the original transformer and the fast charging / supercharging charging pile. However, due to the need for transformer capacity expansion or addition, it is not conducive to the rapid access of fast charging / supercharging charging piles and will increase costs.

[0133] Based on this, the present application provides a charging and storage system. Without the need to additionally configure a transformer or expand the transformer capacity, by configuring an energy storage unit inside the charging device, not only can the fast charging of the charging device be achieved, such as fast charging / super charging, but also the cost brought by adding a new transformer or expanding the transformer can be reduced.

[0134] The charging device disclosed in the embodiments of the present application can be used to charge devices that require fast charging / super charging, such as electric vehicles, electric ships, and electric tools, and can also be used to charge devices that do not require fast charging / super charging, such as electric vehicles, electric ships, and electric tools. That is to say, the charging device disclosed in the embodiments of the present application can achieve charging of electrical equipment with high power and low power, and has a wide range of applications.

[0135] The charging and storage system of the present application will be described below with reference to specific embodiments.

[0136] Figure 1 It is a schematic structural diagram of a charging device 100 according to an embodiment of the present application.

[0137] Referring to Figure 1 , the charging device 100 may include: an energy storage module 110 and a charging module 120.

[0138] The energy storage module 110 includes one or more energy storage units, namely energy storage unit A1,..., energy storage unit A n-1 and energy storage unit A n (n is a positive integer). Each energy storage unit has a first positive power supply terminal (+) and a first negative power supply terminal (-). One or more energy storage units are connected to the second positive power supply terminal (+) and the second negative power supply terminal (-) of the energy storage module 110 through the first positive power supply terminal and the first negative power supply terminal. The energy storage module 110 is configured to provide first direct current. As an example, the energy storage unit may be an electrical box.

[0139] The charging module 120 is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. The charging module 120 is configured to be suitable for charging output based on the first direct current. The maximum charging output power of the charging module 120 is greater than or equal to 350 kilowatts, and / or the rated charging output power of the charging module 120 is greater than or equal to 290 kilowatts.

[0140] Specifically, the number of energy storage units can be selected and set based on actual needs. When the charging device 100 is only used for low-power charging, the energy storage unit can be set to one or a small number of several, which can meet the low-power charging application scenario at this time; when the charging device 100 is used for high-power charging, the energy storage unit can be set to multiple, which can meet the high-power and low-power charging application scenarios at this time. For example, adjusting the charging output power of the energy storage unit, the charging module, or the energy storage unit and the charging module can perform high-power or low-power charging. Due to the modularity of the energy storage unit, the energy storage unit can be freely increased or decreased, and can be quickly accessed to achieve high-power charging, without the need to increase the transformer or expand the transformer capacity.

[0141] When there is one energy storage unit, the first positive power supply terminal of the energy storage unit is connected to the second positive power supply terminal of the energy storage module 110, and the first negative power supply terminal of the energy storage unit is connected to the second negative power supply terminal of the energy storage module 110. The second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 are also connected to the charging module 120. When charging, the energy storage module 110 provides the first direct current through the energy storage unit, and the charging module 120 converts the first direct current to obtain the target direct current to charge the device to be charged. At this time, the charging device 100 can meet the low-power charging application scenario. It should be noted that the relevant parameters of the energy storage unit and the charging module 120 can be set based on the actual situation, and the charging requirements can be met through reasonable parameter configuration.

[0142] When there are multiple energy storage units, the multiple energy storage units can be connected in series, parallel, or series-parallel, and are connected to the charging module 120 through the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. For example, in Figure 1 Energy storage unit A1,..., energy storage unit An-1, and energy storage unit An are connected in series between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 through their respective first positive power supply terminals and first negative power supply terminals. At the same time, the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 are also connected to the charging module 120. When charging, when high-power charging is required, the energy storage module 110 provides the first direct current through multiple energy storage units, and the first direct current can have a higher power. Then the charging module 120 converts the first direct current to obtain the target direct current to charge the device to be charged, and the target direct current has a higher power, so that the high-power charging application scenario can be met; when low-power charging is required, the first direct current can have a lower power, and at the same time the target direct current has a lower power, so that the low-power charging application scenario can be met. It should be noted that the relevant parameters of the energy storage unit and the charging module 120 can be set based on the actual situation, and the charging requirements can be met through reasonable parameter configuration. When there are multiple energy storage units, the power of the energy storage module is the sum of the powers of multiple energy storage units.

[0143] Exemplarily, the maximum charging output power of the charging module 120 is greater than or equal to 350 kW, that is, the maximum charging output power of the charging device 100 is greater than or equal to 350 kW. For example, by selecting an appropriate number of energy storage units, the maximum charging output power of the charging module 120 can reach 350 kW, 360 kW, 500 kW, 800 kW, 900 kW, etc. It should be noted that the charging output power here refers to the maximum charging output power, and during actual charging, it can be downward compatible. For example, when the maximum charging output power is 360 kW, it means that the charging device 100 can output a charging output power of 0 to 360 kW to meet different charging requirements.

[0144] It can be understood that there is a certain multiple relationship between the maximum charging output power and the rated charging output power of the charging module 120, such as a multiple relationship of 1.1 to 1.2. Therefore, the rated charging output power of the charging module 120 can be greater than or equal to 290 kW, that is, the rated charging output power of the charging device 100 is greater than or equal to 290 kW.

[0145] In practical applications, the maximum charging output power of the charging module 120 can be limited, the rated charging output power can be limited, or both can be limited simultaneously.

[0146] In the above embodiments, by configuring modular energy storage units inside the charging device or setting modular energy storage units and modular charging units outside the charging device, that is, setting an energy storage module and a charging module outside the charging device, the energy storage units and the charging units can be freely increased or decreased. When high-power charging is required, through the free and rapid access of the energy storage units, not only can high-power charging be achieved, such as fast charging / ultra-fast charging, but also there is no need to additionally increase the transformer or expand the transformer capacity, which can reduce the transformer cost.

[0147] In some embodiments, referring to Figure 2 , the charging device 100 further includes: an input module 130, and the input module 130 is adapted to provide charging energy for each energy storage unit.

[0148] In one example, the input module 130 can be an AC-DC conversion unit. Taking the input module 130 as an AC-DC conversion unit as an example, the input module 130 can be adapted to provide charging energy for the energy storage unit. In different power usage environments, whether it is an old urban area with relatively tight power supply or a remote area sensitive to infrastructure construction costs, the charging device, by virtue of the cooperation between the input module 130 and the energy storage module 110, adjusts the power supply parameters to the energy storage module 110 using the input module 130, thereby achieving the function of fast charging without relying on complex external power supply upgrades, enhancing the applicability and flexibility of the charging device in various scenarios.

[0149] Thus, the power grid can charge the energy storage unit through the input module 130.

[0150] In some embodiments, the maximum output power of the input module 130 is less than or equal to 150 kW, and / or the rated output power of the input module 130 is less than or equal to 125 kW.

[0151] Specifically, the input module 130 is mainly used to charge each energy storage unit in the energy storage module 110, and the charging is at low power. Exemplarily, the maximum output power of the input module 130 is less than or equal to 150 kW. For example, the maximum output powers are 150 kW, 100 kW, 85 kW, etc. It should be noted that the output power here refers to the maximum output power, and during actual charging, it can be downward compatible. For example, when the maximum output power is 150 kW, it means that the output power of 0 - 150 kW can be used to charge each energy storage unit in the energy storage module 110.

[0152] In this example, the input module 130 has a low-power output, while the charging module 120 can have a high-power output. Therefore, the entire charging device 100 can achieve high-power output with a low-power input. For example, the input end of the transformer is connected to the AC power grid, and the output end of the transformer is connected to the input module 130. When the transformer is a small-capacity transformer, due to the capacity limitation of the transformer, the maximum output power of the input module 130 will also be limited. For example, the maximum output power is 150 kW. At this time, each energy storage unit in the energy storage module 110 is charged with low power, but when the energy storage module 110 discharges externally to charge the device to be charged, high-power charging can be achieved based on multiple energy storage units. For example, the maximum charging output power of the charging module 120 is 360 kW. In this way, high-power output with low-power input is achieved, enabling the charging device to meet the high-power charging demand without additional transformers or transformer capacity expansion. Those skilled in the art can understand that the power grid generally refers to a system that can provide electricity. As an example, the power grid can be the power source of municipal electricity.

[0153] It can be understood that there is a certain multiple relationship between the maximum output power and the rated output power of the input module 130, such as a multiple relationship of 1.1 to 1.2. Therefore, the rated output power of the input module 130 can be less than or equal to 125 kW.

[0154] In practical applications, the maximum output power of the input module 130 can be limited, the rated output power can be limited, or both can be limited simultaneously.

[0155] In the above embodiments, by configuring a modular energy storage unit inside the charging device 100 and limiting the maximum output power and / or rated power of the input module 130 within the above range, the charging device 100 can be flexibly connected to the power grid. Specifically, since the output power of most public power grids or commercial power interfaces is limited to a certain extent, the power setting of the input module 130 can smoothly obtain charging energy from the conventional power environment without modifying the existing power supply lines, improving the access feasibility of the charging device 100 in various power usage scenarios to facilitate the installation of the charging device 100; moreover, it can achieve high-power charging with a small-power input, enabling the charging device 100 to meet the high-power charging requirements without additionally increasing the transformer or expanding the transformer capacity. During the peak power consumption period, when multiple electrical devices are running simultaneously, the energy storage module supplies power to multiple electrical devices, and the input module 130 stably charges the energy storage unit with a lower power, which can effectively reduce the impact of the charging device 100 on the power grid during the charging process and contribute to maintaining the stability of the power grid.

[0156] In some embodiments, the ratio between the maximum charging output power of the charging module 120 and the maximum output power of the input module 130 is greater than 1 and less than or equal to 15, and / or the ratio between the rated charging output power of the charging module 120 and the rated output power of the input module 130 is greater than 1 and less than or equal to 15.

[0157] Specifically, the maximum charging output power of the charging module 120 is greater than the maximum output power of the input module 130, that is, the ratio of the maximum charging output power of the charging module 120 to the maximum output power of the input module 130 is greater than 1. For example, the ratio of the maximum charging output power of the charging module 120 to the maximum output power of the input module 130 can be greater than 2, greater than 2.3, greater than 3, greater than 4, greater than 8, or greater than 12.5, etc., so as to achieve high-power output with a small-power input. Exemplarily, when the ratio is 12.5, it means that the maximum charging output power of the charging module 120 is 12.5 times the maximum output power of the input module 130. Assuming the maximum output power of the input module 130 is 40 kW, then the maximum charging output power of the charging module 120 is greater than or equal to 500 kW.

[0158] Meanwhile, the ratio of the maximum charging output power of the charging module 120 to the maximum output power of the input module 130 is less than or equal to 15. For example, it can be 15, 12.5, 10.3, 9, 7, 6, etc. Exemplarily, when the ratio is 6, it means that the maximum charging output power of the charging module 120 is 6 times the maximum output power of the input module 130. Assuming the maximum output power of the input module 130 is 150 kW, then the maximum charging output power of the charging module 120 is less than or equal to 900 kW.

[0159] It should be noted that when setting the above ratio, the minimum ratio is less than or equal to the maximum ratio. For example, the ratio between the maximum charging output power of the charging module 120 and the maximum output power of the input module 130 is greater than 2 and less than or equal to 15, or greater than 1 and less than or equal to 6, or greater than 6 and less than or equal to 12.5, etc. Specifically, it is selected and set according to actual requirements.

[0160] In this way, by restricting the ratio between the maximum charging output power of the charging module 120 and the maximum output power of the input module 130, it is possible to have a high cost performance and good performance when achieving low-power input and high-power output.

[0161] It can be understood that there is a certain multiple relationship between the maximum charging output power of the charging module 120 and the rated charging output power, such as a multiple relationship of 1.1 to 1.2. Meanwhile, there is a certain multiple relationship between the maximum output power of the input module 130 and the rated output power, such as a multiple relationship of 1.1 to 1.2. Therefore, the ratio between the rated charging output power of the charging module 120 and the rated output power of the input module 130 can also be greater than 1 and less than or equal to 15.

[0162] In practical applications, the ratio between the maximum charging output power of the charging module 120 and the maximum output power of the input module 130 can be restricted, or the ratio between the rated charging output power of the charging module 120 and the rated output power of the input module 130 can be restricted, or both can be restricted simultaneously.

[0163] In the above embodiment, by limiting the ratio of the maximum charging output power of the charging module to the maximum output power of the input module, and / or limiting the ratio of the rated charging output power of the charging module to the rated output power of the input module, on the one hand, the current shock, overheating and other problems caused by the instantaneous excessive power input of the charging module 120 can be reduced. On the other hand, the input module 130 can charge the energy storage module 110 with low power, and the energy storage module then outputs controllable high power to the charging module 120, so that low power is input to the energy storage module 110 and high power is output from the charging module 120. In addition, the energy storage module 110 can flexibly adjust the output power according to the amount of electricity stored in itself and the power demand of the electrical equipment, so that the charging device 100 can reasonably distribute the electric energy, reduce unnecessary energy consumption, improve the cost performance of the charging device 100, and enable the charging device 100 to operate smoothly when the low power input and high power output are achieved.

[0164] In some embodiments, each energy storage unit includes a battery subunit, and the ratio between the rated output power of the input module 130 and the rated energy of the battery subunit is greater than or equal to 1 / n1, where the value range of n1 is 1-4.

[0165] Specifically, the rated energy of the battery subunit refers to the energy capacity specified in the design of the battery subunit, which represents the maximum energy value that the battery subunit can store or output under normal working conditions, in kilowatt-hours. The rated output power of the input module 130 is ≥ the rated energy of the battery subunit / n1 / 100%, where n1 can be 1, 1.4, 2, 3, and 4, etc. By specifying that the rated output power of the input module is greater than the rated energy of the battery subunit divided by the coefficient n1, when the input power of the input module 130 is small, the rated energy of the battery subunit is small, so that the input power and the rated energy of the battery subunit match, and the input module 130 will not charge the battery subunit too slowly, affecting the use of the energy storage unit; at the same time, specifying that the rated energy of the battery subunit is small can also mean that the battery subunit is small in size, so that the energy storage unit occupies a small area and is easy to install; further realizing a small-volume energy storage unit, realizing small-power input and high-power output, and improving user experience.

[0166] In some embodiments, each energy storage unit includes a battery subunit, and the ratio between the rated energy of the battery subunit and the rated charging output power of the charging module 120 is greater than or equal to 1 / (n2*n3), where the value range of n2 is 94%~99%, and the value range of n3 is 4~6.

[0167] That is to say, the rated energy of the battery subunit ≥ the rated charging output power of the charging module 120 / (n2 * n3) * 100%, where n2 can be 94%, 96%, 98.5%, 99%, etc., and n3 can be 4, 5, 5.5, 6, etc. With such settings, while ensuring the charging performance, the reliability of the charging device 100 is taken into account. When the rated energy of the battery subunit matches the rated charging output power of the charging module 120, during the charging process, the battery subunit can stably supply energy to the charging module 120, reducing the instability or interruption of the charging power caused by insufficient energy supply. Taking n2 = 94% and n3 = 6 as an example, the relatively large denominator requires the battery subunit to have a relatively high rated energy to match the power of the charging module 120. This enables the charging device 100 to continuously and stably operate during long-term and high-power charging, reducing the probability of failures, lowering the maintenance cost, thus extending the service life of the charging device 100 and enhancing the cost performance.

[0168] In some embodiments, each energy storage unit includes a battery subunit, and the ratio between the rated energy and the rated power of the battery subunit is less than or equal to 1 / 3, and / or the volumetric energy density of the battery subunit is greater than 380 watt-hours per liter.

[0169] That is to say, the ratio of the rated energy to the rated power of the battery subunit is not greater than 1:3. Exemplarily, when the rated power of the battery subunit is 350 kW, the rated energy of the battery subunit is 58 kWh. Such settings can improve the cost performance of the entire charging device.

[0170] The volumetric energy density of the battery subunit is greater than or equal to 380 watt-hours per liter, for example, it can be 380 watt-hours per liter, 400 watt-hours per liter, 600 watt-hours per liter, or 900 watt-hours per liter, etc. It can be understood that the higher the energy density of the battery subunit, the smaller the corresponding volume, thus saving space and reducing the construction cost, while being able to provide high-power output.

[0171] When the charging device 100 outputs at high power (the maximum charging output power of the charging module is above 350 kW), the ratio between the rated energy and the rated power of the battery subunit is less than or equal to 1 / 3, and / or the volumetric energy density of the battery subunit is greater than 380 watt-hours per liter, enabling the rated energy of the battery subunit to match the rated power, reducing the grid fluctuations caused by the insufficient rated energy of the battery subunit due to high-power output and requiring grid power supply, which is beneficial to improving the reliability and stability of the charging device 100. And when outputting at high power, the charging device 100 can continuously and stably operate, reducing the probability of failures, lowering the maintenance cost, thus extending the service life of the charging device 100 and enhancing the cost performance.

[0172] In some embodiments, each energy storage unit includes a battery subunit, and the maximum discharge rate of the battery subunit is greater than or equal to 4C. For example, the maximum discharge rate is greater than or equal to 5C, 6C, 7C, or 8C, etc. In this way, high-power output can be provided.

[0173] It should be noted that the above parameters can be superimposed. Exemplarily, when the maximum charging output power of the charging module 120 is greater than or equal to 350 kW, the maximum output power of the battery subunit is greater than or equal to 350 kW, the rated power of the battery subunit is greater than or equal to 350 kW, the rated energy of the battery subunit is greater than or equal to 58 kWh, the maximum discharge rate of the battery subunit is greater than or equal to 4C, and the maximum output power of the input module 130 can be less than or equal to 150 kW.

[0174] It should be noted that the above relevant parameters of the battery subunit also apply to the energy storage unit and / or the energy storage module in some cases. That is to say, in some cases, the above parameters apply to the energy storage unit, the energy storage module, and the battery subunit. Exemplarily, when the energy storage unit only includes a battery subunit, the relevant parameters of this battery subunit are also the relevant parameters of the energy storage unit. Further, when the energy storage module 110 includes one energy storage unit, the relevant parameters of this battery subunit are also the relevant parameters of the energy storage module 110; and so on.

[0175] It should be noted that the energy storage unit can include one or more battery subunits, and multiple battery subunits can be connected in series, parallel, or in series-parallel. Each battery subunit can be a single cell, or can be formed by multiple single cells connected in series, parallel, or in series-parallel. Exemplarily, the single cell can include 10 to 100, and by combining the single cells, 2 to 6 battery subunits can be obtained, and the 2 to 6 battery subunits are connected in series and / or parallel. Through the 2 to 6 battery subunits, the power of the energy storage unit can reach 80 kWh to 150 kWh. For example, the power can reach 80 kWh through the combination of 2 single cells; another example is that the power reaches 150 kWh through the combination of 100 single cells; and another example is that the power reaches 90 kWh through the combination of 80 single cells; and so on.

[0176] In the above embodiments, by restricting the proportional relationship of the rated energy and rated power of the battery subunit, the rated output power of the input module, and the rated charging output power of the charging module, etc., the entire charging device can have a high cost performance.

[0177] In some embodiments, one or more energy storage units are connected in series and / or parallel between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 through the first positive power supply terminal and the first negative power supply terminal to provide a first direct current.

[0178] Specifically, when there is one energy storage unit, the first positive power supply terminal of the energy storage unit is connected to the second positive power supply terminal of the energy storage module 110, and the first negative power supply terminal of the energy storage unit is connected to the second negative power supply terminal of the energy storage module 110, and the first direct current is provided by the energy storage unit.

[0179] When there are multiple energy storage units, the multiple energy storage units can be connected in series, in parallel, or in a combination of series and parallel. For example, referring to Figure 1 , the multiple energy storage units are connected in series between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 through their own first positive power supply terminals and first negative power supply terminals; another example, referring to Figure 3 , the multiple energy storage units are connected in parallel between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 through their own first positive power supply terminals and first negative power supply terminals; yet another example, the multiple energy storage units can be first connected in series and then in parallel, or first connected in parallel and then in series between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. The first direct current is provided after the multiple energy storage units are connected in series, in parallel, or in a series-parallel combination, and the specific connection method can be selected based on the actual situation.

[0180] In the above embodiments, the multiple energy storage units can be connected in series, in parallel, or in a series-parallel combination, which can realize the free access of the energy storage units to meet different charging power requirements.

[0181] In some embodiments, referring to Figures 4a - 4d , each energy storage unit includes a battery subunit, and each energy storage unit is configured to provide a second direct current based on the electrical energy of the battery subunit.

[0182] Exemplarily, referring to Figure 4a , the energy storage unit A1 includes the battery subunit BAT1,..., the energy storage unit A n-1 includes the battery subunit BAT n-1 , the energy storage unit A n includes the battery subunit BAT n . Each energy storage unit provides a second direct current based on the electrical energy of the battery subunit, and the multiple energy storage units provide the first direct current to the charging module 120 after being connected in series and / or in parallel.

[0183] In some embodiments, referring to Figure 4b, at least some of the one or more energy storage units further include a first power conversion subunit, which is respectively connected to the corresponding battery subunit and the first positive power terminal and the first negative power terminal of the energy storage unit, and is configured to convert the electrical energy of the battery subunit into a second direct current; wherein, in the case where the energy storage unit does not include the first power conversion subunit, the battery subunit is directly connected to the first positive power terminal and the first negative power terminal of the corresponding energy storage unit to provide the second direct current.

[0184] Specifically, when there is one energy storage unit, the energy storage unit further includes a first power conversion subunit to convert the electrical energy of the battery subunit into a second direct current.

[0185] When there are multiple energy storage units, a first power conversion subunit can be provided in each of the multiple energy storage units, or a first power conversion subunit can be provided in some of the multiple energy storage units. Exemplarily, in Figure 4b , the energy storage unit A1 includes a battery subunit BAT1 and a first power conversion subunit B1. The first power conversion subunit B1 is respectively connected to the battery subunit BAT1 and the first positive power terminal and the first negative power terminal of the energy storage unit A1, and converts the electrical energy of the battery subunit BAT1 into a second direct current through the first power conversion subunit B1;...; the energy storage unit A n-1 includes a battery subunit BAT n-1 and a first power conversion subunit B n-1 , the first power conversion subunit Bn-1 is respectively connected to the battery subunit BAT n-1 and the first positive power terminal and the first negative power terminal of the energy storage unit A n-1 , and converts the electrical energy of the battery subunit BAT n-1 into a second direct current through the first power conversion subunit B n-1 ; the energy storage unit A n includes a battery subunit BAT n , the battery subunit BAT n is directly connected to the first positive power terminal and the first negative power terminal of the energy storage unit A n to provide the second direct current.

[0186] In some embodiments, when the battery subunit discharges externally, the maximum output power of the first power conversion subunit is greater than or equal to 350 kilowatts, and / or the rated output power is greater than or equal to 310 kilowatts. When the battery subunit is charging, the ratio of the maximum output power of the input module 130 to the maximum output power of the first power conversion subunit is not greater than 1:4, and / or the ratio of the rated output power of the input module 130 to the rated output power of the first power conversion subunit is not greater than 1:4.

[0187] In the above embodiments, some or all of the multiple energy storage units may be provided with a first power conversion subunit. The electrical energy of the battery subunit is converted by the first power conversion subunit to provide a second direct current. In this way, the charging flexibility can be improved. At the same time, by partially providing the first power conversion subunit, the cost can be reduced while meeting the charging requirements. Moreover, this method can realize the access of the energy storage unit with the first power conversion subunit and the energy storage unit without the first power conversion subunit, and has high applicability.

[0188] In some embodiments, referring to Figure 4c , at least some of the one or more energy storage units further include a first switch subunit. The first switch subunit is respectively connected to the corresponding battery subunit and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit, and is configured to connect the corresponding battery subunit to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit when conducting, so as to provide a second direct current. Wherein, when the energy storage unit does not include the first switch subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide a second direct current.

[0189] Specifically, when there is one energy storage unit, the energy storage unit further includes a first switch subunit. When the first switch subunit conducts, the battery subunit is connected to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit to provide a second direct current. In case of an abnormality, such as an abnormality of the battery subunit or the charging module 120, etc., the first switch subunit disconnects to reduce the further occurrence of abnormal accidents. When the battery subunit does not need to work, such as when the energy storage unit does not need to work based on the power demand, the first switch subunit disconnects to stop the battery subunit from providing the second direct current.

[0190] When there are multiple energy storage units, a first switch subunit may be provided in each of the multiple energy storage units, or a first switch subunit may be provided in some of the multiple energy storage units. Exemplarily, in Figure 4c , the energy storage unit A1 includes a battery subunit BAT1 and a first switch subunit C1. The first switch subunit C1 is respectively connected to the battery subunit BAT1 and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A1. The on-off of the connection between the battery subunit BAT1 and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A1 is controlled by the first switch subunit C1 to selectively provide a second direct current;...; the energy storage unit A n-1 includes a battery subunit BAT n-1 and a first switch subunit C n-1 , the first switch subunit C n-1 is respectively connected to the battery subunit BAT n-1 and the energy storage unit A n-1The first positive power supply terminal and the first negative power supply terminal are connected, and the battery sub-unit BAT is controlled through the first switch sub-unit C n-1 to control the battery sub-unit BAT n-1 to selectively provide the second direct current with respect to the on / off of the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A; the energy storage unit A n-1 includes the battery sub-unit BAT n The battery sub-unit BAT n is directly connected to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A n to provide the second direct current. n In the above embodiments, some or all of the multiple energy storage units may be provided with the first switch sub-unit, and the battery sub-unit is selectively controlled through the first switch sub-unit to provide the second direct current, so that the charging flexibility and protection in abnormal situations can be improved.

[0191] In some embodiments, referring to

[0192] , at least some of the one or more energy storage units further include a first power conversion sub-unit and a first switch sub-unit. The first power conversion sub-unit and the first switch sub-unit are connected in series between the corresponding battery sub-unit and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit. The first power conversion sub-unit is configured to convert the electrical energy of the battery sub-unit into the second direct current when the corresponding first switch sub-unit is turned on; wherein, when the energy storage unit does not include the first power conversion sub-unit and the first switch sub-unit, the battery sub-unit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current. Figure 4d Specifically, when there is one energy storage unit, the energy storage unit further includes a first power conversion sub-unit and a first switch sub-unit. When the first switch sub-unit is turned on, the first power conversion sub-unit converts the electrical energy of the battery sub-unit into the second direct current; in abnormal situations, such as when the battery sub-unit or the charging module 120 is abnormal, the first switch sub-unit is turned off and the first power conversion sub-unit stops working to reduce the further occurrence of abnormal accidents; when the battery sub-unit does not need to work, such as when the energy storage unit does not need to work based on the power demand, the first switch sub-unit is turned off and the first power conversion sub-unit stops working to stop the battery sub-unit from providing the second direct current.

[0193] When there are multiple energy storage units, a first switch sub-unit and a first power conversion sub-unit may be provided in each of the multiple energy storage units, or a first switch sub-unit and a first power conversion sub-unit may be provided in some of the multiple energy storage units. Exemplarily, in

[0194] When there are multiple energy storage units, a first switch sub-unit and a first power conversion sub-unit may be provided in each of the multiple energy storage units, or a first switch sub-unit and a first power conversion sub-unit may be provided in some of the multiple energy storage units. Exemplarily, in Figure 4dAmong them, the energy storage unit A1 includes a battery subunit BAT1, a first switch subunit C1, and a first power conversion subunit B1. The first switch subunit C1 and the first power conversion subunit B1 are connected in series between the battery subunit BAT1 and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A1. When the first switch subunit C1 is turned on, the first power conversion subunit B1 converts the electrical energy of the battery subunit BAT1 into second direct current electricity;...; the energy storage unit A n-1 includes a battery subunit BAT n-1 , a first switch subunit C n-1 and a first power conversion subunit B n-1 , the first switch subunit C n-1 and the first power conversion subunit B n-1 are connected in series between the battery subunit BAT n-1 and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A n-1 . When the first switch subunit C n-1 is turned on, the first power conversion subunit B n-1 converts the electrical energy of the battery subunit BAT n-1 into second direct current electricity; the energy storage unit A n includes a battery subunit BAT n , the battery subunit BAT n is directly connected to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A n to provide second direct current electricity.

[0195] It should be noted that in some embodiments, some of the energy storage units may include the first switch subunit, and some may include the first power conversion subunit, and specific limitations are not made here.

[0196] In the above embodiments, some or all of the multiple energy storage units may be provided with the first switch subunit and the first power conversion subunit, so as to improve the charging flexibility and the protection ability in abnormal situations.

[0197] In some embodiments, the first power conversion subunit is a bidirectional DCDC subunit, and the charging and discharging of the battery subunit are realized through the bidirectional DCDC subunit. The bidirectional DCDC subunit includes, but is not limited to, a BUCK-BOOST circuit, etc., and specific limitations are not made here.

[0198] In some embodiments, referring to Figure 5a , the input module 130 includes input interfaces (X, Y). The input interfaces are connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110, and are configured to provide charging energy for each energy storage unit based on the third direct current electricity provided by the first external power supply 210.

[0199] Specifically, the first external power supply 210 is used to generate a third direct current and transmit it to the energy storage module 110 through the input interface to charge each energy storage unit in the energy storage module 110. Exemplarily, the first external power supply 210 may include a first transformer and a first AC-DC conversion module. The primary winding of the first transformer is connected to the AC power grid to convert the second alternating current provided by the AC power grid into a first alternating current; the first AC-DC conversion module is respectively connected to the secondary winding of the first transformer and the input interface to convert the first alternating current into a third direct current and transmit it to the energy storage module 110 through the input interface.

[0200] The first AC-DC conversion module may be a unidirectional ACDC sub-unit or a bidirectional ACDC sub-unit. When the first AC-DC conversion module is a bidirectional ACDC sub-unit, it can not only charge the energy storage module 110, but also feed the electric energy of the energy storage module 110 to the AC power grid. The specific circuit structure of the unidirectional ACDC sub-unit or the bidirectional ACDC sub-unit is not limited here.

[0201] It should be noted that in this example, the maximum output power and the rated output power of the input module 130 are also the maximum output power and the rated output power of the first external power supply 210.

[0202] In the above embodiments, when the external power supply provides direct current, the battery sub-units can be charged through the input interface.

[0203] In some embodiments, referring to Figure 5b , the input module 130 includes a second power conversion sub-unit 131. The second power conversion sub-unit 131 is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 and is configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply 220.

[0204] Specifically, the second external power supply 220 is used to generate a first alternating current and provide it to the second power conversion sub-unit 131 in the input module 130 to charge each battery sub-unit in the energy storage module 110 through the second power conversion sub-unit 131. Exemplarily, the second external power supply 220 may include a first transformer. The primary winding of the first transformer is connected to the AC power grid. The second power conversion sub-unit 131 is respectively connected to the secondary winding of the first transformer and the energy storage module 110. The first transformer converts the second alternating current provided by the AC power grid into a first alternating current and provides it to the second power conversion sub-unit 131, and the second power conversion sub-unit 131 converts the first alternating current into a third direct current to charge the energy storage module 110.

[0205] The second power conversion subunit 131 can be a unidirectional ACDC subunit or a bidirectional ACDC subunit. When the second power conversion subunit 131 is a bidirectional ACDC subunit, it can not only charge the energy storage module 110, but also feed the electric energy of the energy storage module 110 to the AC power grid. The specific circuit structure of this unidirectional ACDC subunit or bidirectional ACDC subunit is not limited here.

[0206] It should be noted that in this example, the maximum output power and rated output power of the input module 130 are also the maximum output power and rated output power of the second power conversion subunit 131.

[0207] In the above embodiment, when an external power supply provides alternating current, the battery subunit can be charged through the second power conversion subunit.

[0208] In some embodiments, please refer to Figure 6a 、 6b 、9a, 9b, 11a, 11b and Figures 14 - 22 , the charging module 120 includes a charging module conversion unit and at least one charging gun 122. The charging gun 122 is connected to the energy storage module 110 through the charging module conversion unit.

[0209] The number of charging guns 122 can be one, two or more than three. Exemplarily, the number of charging guns 122 is two. The maximum charging output power or rated output power of each charging gun 122 can be 500 kW, and it can charge the same electrical device at the same time. The electrical device can be an electric vehicle, and each charging gun 122 can also charge different electrical devices separately.

[0210] When the number of charging guns 122 is multiple, multiple charging guns 122 can be connected to the energy storage module 110 through the same charging module conversion unit, and each charging gun 122 can also be separately connected to the energy storage module 110 through a charging module conversion unit. The charging module conversion unit can be a DCDC conversion unit, specifically a unipolar unidirectional DCDC conversion unit or a unipolar bidirectional DCDC conversion unit, and can also be a bipolar unidirectional DCDC conversion unit or a bipolar bidirectional DCDC conversion unit.

[0211] The conversion unit of the charging module can flexibly adjust parameters such as voltage and current according to the direct current output by the energy storage module 110 and the requirements of the device (such as an electric vehicle) connected to the charging gun 122, so as to achieve efficient charging output. The configuration of at least one charging gun 122 enables the charging device 100 to charge one or more electrical devices simultaneously. In public charging areas, such as parking lots and charging stations, multiple users can simultaneously use different charging guns 122 to charge their electric vehicles, improving the usage efficiency and service capacity of the charging device 100, meeting the usage requirements in scenarios with large-scale charging demands, effectively alleviating the problem of queuing for charging, and enhancing the user experience.

[0212] In some embodiments, referring to Figure 6a , the charging module 120 includes a third power conversion subunit 121 and a charging gun 122. The positive input terminal and the negative input terminal of the third power conversion subunit 121 are correspondingly connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. The positive output terminal and the negative output terminal of the third power conversion subunit 121 are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun 122. The third power conversion subunit 121 is configured to convert the first direct current into a fourth direct current for charging output through the charging gun 122.

[0213] Specifically, when charging a device to be charged, one or more energy storage units provide a second direct current, so that the energy storage module 110 provides a first direct current. The first direct current is converted into a fourth direct current by the third power conversion subunit 121 and provided to the charging gun 122, and is provided by the charging gun 122 to the device to be charged to charge the device to be charged.

[0214] In this example, the third power conversion subunit 121 has bipolarity, that is, it has a positive input terminal and a negative input terminal. At this time, the positive input terminal and the negative input terminal of the third power conversion subunit 121 are directly connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110, and the positive output terminal and the negative output terminal of the third power conversion subunit 121 are directly connected to the positive input terminal and the negative input terminal of the charging gun 122. The negative input terminal of the charging gun 122 and the second negative power supply terminal of the energy storage module 110 are not shared. In this way, it is applicable to the application scenario where the third power conversion subunit 121 has bipolarity.

[0215] The third power conversion subunit 121 can be a bipolar unidirectional DCDC subunit or a bipolar bidirectional DCDC subunit. When the third power conversion subunit 121 is a bipolar bidirectional DCDC subunit, not only can the device to be charged be charged, but also the electrical energy of the device to be charged can be fed back to the energy storage module 110, and can also be fed back to the AC power grid in the foregoing example through the input module 130, ultimately realizing the free conversion of electrical energy among the grid, charging, and storage.

[0216] In some embodiments, referring to Figure 6b , the charging module 120 includes a fourth power conversion subunit 123 and a charging gun 122. The positive input terminal of the fourth power conversion subunit 123 is connected to the second positive power supply terminal of the energy storage module 110. The positive output terminal of the fourth power conversion subunit 123 is connected to the positive input terminal of the charging gun 122. The negative input terminal of the charging gun 122 is connected to the second negative power supply terminal of the energy storage module 110. The fourth power conversion subunit 123 is configured to convert the first direct current into a fourth direct current for charging output through the charging gun 122.

[0217] Specifically, when charging a device to be charged, one or more energy storage units provide a second direct current, so that the energy storage module 110 provides a first direct current. The first direct current is converted into a fourth direct current by the fourth power conversion subunit 123 and provided to the charging gun 122, and is provided by the charging gun 122 to the device to be charged to charge the device to be charged.

[0218] In this example, the fourth power conversion subunit 123 has a single polarity, that is, it only has a positive input terminal. At this time, the positive input terminal of the fourth power conversion subunit 123 is directly connected to the second positive power supply terminal of the energy storage module 110. The positive output terminal of the fourth power conversion subunit 123 is directly connected to the positive input terminal of the charging gun 122. The negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110, that is, the negative input terminal of the charging gun 122 and the second negative power supply terminal of the energy storage module 110 are shared. In this way, it is applicable to the application scenario where the fourth power conversion subunit 123 has a single polarity and has a low cost.

[0219] The fourth power conversion subunit 123 can be a single-polarity unidirectional DCDC subunit or a single-polarity bidirectional DCDC subunit. When the fourth power conversion subunit 123 is a single-polarity bidirectional DCDC subunit, not only can the device to be charged be charged, but also the electric energy of the device to be charged can be fed to the energy storage module 110, and can also be fed to the AC power grid in the foregoing example through the input module 130, finally realizing the free conversion of electric energy among the grid, charging, and energy storage.

[0220] In the above embodiments, by sharing or not sharing the negative input terminal of the charging gun, different power supply scenarios can be adapted, and the selection range during the circuit structure selection is increased.

[0221] In some embodiments, referring to Figure 7 , the energy storage module 110 further includes a selection unit 111. The selection unit 111 is connected to one or more energy storage units and is configured to select at least one energy storage unit from the one or more energy storage units and connect it to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 to provide a first direct current.

[0222] Specifically, during charging, the selection unit 111 can select an energy storage unit A1 to be connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 to provide a first direct current; alternatively, all the energy storage units A1, ..., energy storage unit A n-1 and energy storage unit A n are connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 to provide a first direct current. Then, the charging module 120 performs a charging output based on the first direct current.

[0223] In the above embodiment, by selectively controlling the output of the energy storage unit through the selection unit, the flexibility of charging can be improved to meet different charging requirements.

[0224] In some embodiments, referring to Figure 8 , both the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 include one. The selection unit 111 includes a plurality of second switch sub-units. Each second switch sub-unit is connected to an energy storage unit. Each second switch sub-unit is connected in series between the first positive power supply terminal of the corresponding energy storage unit and the second positive power supply terminal of the energy storage module 110. The first negative power supply terminals of one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module 110. The second switch sub-unit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the second positive power supply terminal of the energy storage module 110 when conducting.

[0225] Specifically, the selection unit 111 includes second switch sub-units K1, ..., second switch sub-unit Kn-1, second switch sub-unit Kn. Among them, the second switch sub-unit K1 is connected in series between the first positive power supply terminal of the energy storage unit A1 and the second positive power supply terminal of the energy storage module 110, ..., the second switch sub-unit Kn-1 is connected in series between the first positive power supply terminal of the energy storage unit A n-1 and the second positive power supply terminal of the energy storage module 110, and the second switch sub-unit Kn is connected in series between the first positive power supply terminal of the energy storage unit A n and the second positive power supply terminal of the energy storage module 110. By controlling the on / off of the second switch sub-unit, the corresponding energy storage unit is selected to provide a second direct current, and then the energy storage module 110 provides a first direct current. At this time, the charging module 120 converts the first direct current into a fourth direct current to charge the device to be charged.

[0226] In the above embodiment, by providing one second positive power supply terminal and selectively controlling the energy storage unit to provide a second direct current through the selection unit, the flexibility of charging can be improved to meet the charging requirements.

[0227] In some embodiments, referring to Figure 9a, the charging module 120 includes a fifth power conversion subunit 124 and a charging gun 122. The positive input terminal and the negative input terminal of the fifth power conversion subunit 124 are correspondingly connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. The positive output terminal and the negative output terminal of the fifth power conversion subunit 124 are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun 122. The fifth power conversion subunit 124 is configured to convert the first direct current into a fourth direct current for charging output through the charging gun 122.

[0228] It should be noted that for the connection relationship between the fifth power conversion subunit 124 and the charging gun 122 and the energy storage module 110, as well as the structure of the fifth power conversion subunit 124, please refer to the foregoing related description of the third power conversion subunit 121, and details are not elaborated here.

[0229] In some embodiments, referring to Figure 9b , the charging module 120 includes a sixth power conversion subunit 125 and a charging gun 122. The positive input terminal of the sixth power conversion subunit 125 is connected to the second positive power supply terminal of the energy storage module 110. The positive output terminal of the sixth power conversion subunit 125 is connected to the positive input terminal of the charging gun 122. The negative input terminal of the charging gun 122 is connected to the second negative power supply terminal of the energy storage module 110. The sixth power conversion subunit 125 is configured to convert the first direct current into a fourth direct current for charging output through the charging gun 122.

[0230] It should be noted that for the connection relationship between the sixth power conversion subunit 125 and the charging gun 122 and the energy storage module 110, as well as the structure of the sixth power conversion subunit 125, please refer to the foregoing related description of the fourth power conversion subunit 123, and details are not elaborated here.

[0231] In some embodiments, referring to Figure 10 , the second positive power supply terminal of the energy storage module 110 includes multiple ones, and the second negative power supply terminal of the energy storage module 110 includes one. The selection unit 111 includes multiple second switch subunits. Each second switch subunit is connected to an energy storage unit and a second positive power supply terminal. Each second switch subunit is connected in series between the first positive power supply terminal of the corresponding energy storage unit and the corresponding second positive power supply terminal. The first negative power supply terminals of one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module 110. The second switch subunit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the corresponding second positive power supply terminal when conducting.

[0232] Specifically, the selection unit 111 includes a second switch sub-unit K1, ..., a second switch sub-unit Kn-1, and a second switch sub-unit Kn. Among them, the second switch sub-unit K1 is connected in series between the first positive power supply terminal of the energy storage unit A1 and one of the second positive power supply terminals of the energy storage module 110, ..., the second switch sub-unit Kn-1 is connected in series between the first positive power supply terminal of the energy storage unit A n-1 and another second positive power supply terminal of the energy storage module 110, and the second switch sub-unit Kn is connected in series between the first positive power supply terminal of the energy storage unit A n and yet another second positive power supply terminal of the energy storage module 110. By controlling the on / off of the second switch sub-units, the corresponding energy storage unit is selected to provide the second direct current, so that the energy storage module 110 provides the first direct current. At this time, the charging module 120 converts the first direct current into the fourth direct current to charge the device to be charged. It should be noted that the first direct current here includes multiple second direct currents, and the charging module 120 can selectively convert one or more second direct currents into the fourth direct current.

[0233] In the above embodiment, by setting multiple second positive power supply terminals and selectively controlling the energy storage unit to provide the second direct current through the selection unit, the charging flexibility can be improved to meet the charging requirements.

[0234] In some embodiments, referring to Figure 11a , the charging module 120 includes multiple seventh power conversion sub-units and a charging gun 122. The positive input terminal and the negative input terminal of each seventh power conversion sub-unit are correspondingly connected to a second positive power supply terminal and a second negative power supply terminal, and the positive output terminal and the negative output terminal of each seventh power conversion sub-unit are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun. The multiple seventh power conversion sub-units are configured to convert the first direct current into the fourth direct current for charging output through the charging gun.

[0235] Specifically, the multiple seventh power conversion sub-units are respectively the seventh power conversion sub-unit D1, ..., the seventh power conversion sub-unit D n-1 and the seventh power conversion sub-unit D n , among which, the positive input terminal of the seventh power conversion sub-unit D1 is connected to a second positive power supply terminal, ..., the positive input terminal of the seventh power conversion sub-unit D n-1 is connected to another second positive power supply terminal, the positive input terminal of the seventh power conversion sub-unit D n is connected to yet another second positive power supply terminal, and the negative input terminals of the seventh power conversion sub-units D1, ..., the seventh power conversion sub-unit D n-1 and the seventh power conversion sub-unit D n are all connected to the second negative power supply terminal. The positive output terminals of the seventh power conversion sub-units D1, ..., the seventh power conversion sub-unit D n-1and the seventh power conversion subunit D n The positive output terminal and the negative output terminal thereof are respectively and correspondingly connected to the positive input terminal and the negative input terminal of the charging gun 122.

[0236] In this example, each seventh power conversion subunit can convert the second direct current of the corresponding energy storage unit into the fifth direct current, and finally multiple seventh power conversion subunits output the fourth direct current.

[0237] The seventh power conversion subunit can be a bipolar unidirectional DCDC subunit or a bipolar bidirectional DCDC subunit. When the seventh power conversion subunit is a bipolar bidirectional DCDC subunit, it can not only charge the device to be charged, but also feed the electric energy of the device to be charged to the energy storage module 110, and can also be fed to the AC power grid in the foregoing example through the input module 130, and finally realize the free conversion of electric energy among the grid, charging, and storage.

[0238] In some embodiments, referring to Figure 11b , the charging module 120 includes multiple eighth power conversion subunits and a charging gun 122. The positive input terminal of each eighth power conversion subunit is connected to a second positive power supply terminal, the positive output terminal of each eighth power conversion subunit is connected to the positive input terminal of the charging gun 122, the negative input terminal of the charging gun 122 is connected to the second negative power supply terminal of the energy storage module 110, and the multiple eighth power conversion subunits are configured to convert the first direct current into the fourth direct current and output it through the charging gun 122 for charging.

[0239] Specifically, the multiple eighth power conversion subunits are respectively the eighth power conversion subunit E1,..., the eighth power conversion subunit E n-1 and the eighth power conversion subunit E n , where the positive input terminal of the eighth power conversion subunit E1 is connected to a second positive power supply terminal,..., the positive input terminal of the eighth power conversion subunit E n-1 is connected to another second positive power supply terminal, the positive input terminal of the eighth power conversion subunit E n is connected to yet another second positive power supply terminal, and the positive output terminals of the eighth power conversion subunits E1,..., the eighth power conversion subunit E n-1 and the eighth power conversion subunit E n are all connected to the positive input terminal of the charging gun 122, and the negative input terminal of the charging gun 122 is connected to the second negative power supply terminal of the energy storage module 110.

[0240] In this example, each eighth power conversion subunit can convert the second direct current of the corresponding energy storage unit into the fifth direct current, and finally multiple eighth power conversion subunits output the fourth direct current.

[0241] The eighth power conversion subunit can be a unipolar one-way DCDC subunit or a unipolar bidirectional DCDC subunit. When the eighth power conversion subunit is a unipolar bidirectional DCDC subunit, it can not only charge the device to be charged, but also feed the electrical energy of the device to be charged to the energy storage module 110, and can also be fed to the AC power grid in the foregoing example through the input module 130, ultimately realizing the free conversion of electrical energy among the grid, charging, and storage.

[0242] In the above embodiments, by sharing or not sharing the negative input terminal of the charging gun, it can be applicable to different power supply scenarios, improving the selection range during the circuit structure selection.

[0243] In some embodiments, referring to Figure 12a , the input module 130 includes a ninth power conversion subunit 132, and the ninth power conversion subunit 132 is connected to one or more energy storage units and is configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply 220.

[0244] Specifically, the second external power supply 220 is used to generate the first alternating current and provide it to the ninth power conversion subunit 132 in the input module 130, and charge each battery subunit in the energy storage module 110 through the ninth power conversion subunit 132. Exemplarily, the second external power supply 220 may include a second transformer. The primary winding of the second transformer is connected to the AC power grid, and the secondary winding of the second transformer is connected to the ninth power conversion subunit 132. The second transformer converts the second alternating current provided by the AC power grid into the first alternating current and provides it to the ninth power conversion subunit 132, and the ninth power conversion subunit 132 converts the first alternating current into the third direct current to charge the energy storage module 110.

[0245] Exemplarily, the second external power supply 220 is a three-phase AC power supply, and the ninth power conversion subunit 132 is a unidirectional three-phase ACDC subunit or a bidirectional three-phase ACDC subunit. At this time, each phase of the three-phase ACDC subunit is connected to an energy storage unit to charge the corresponding energy storage unit. When the ninth power conversion subunit 132 is a bidirectional three-phase ACDC subunit, not only can the charging of the energy storage module 110 be realized, but also the electrical energy of the energy storage module 110 can be fed to the AC power grid. Thus, in three-phase alternating current, a single phase is realized by an energy storage unit, and three energy storage units can realize the function of three-phase alternating current. For example, three-phase power frequency alternating current with a phase difference of 120°. The specific circuit structure of this unidirectional three-phase ACDC subunit or bidirectional three-phase ACDC subunit is not limited here.

[0246] It should be noted that in this example, the maximum output power and rated output power of the input module 130 are also the maximum output power and rated output power of the ninth power conversion subunit 132.

[0247] In the above embodiments, when the external power supply provides alternating current, the battery subunit can be charged through the ninth power conversion subunit.

[0248] In some embodiments, referring to Figure 12b , the input module 130 includes a plurality of tenth power conversion subunits, each tenth power conversion subunit is connected to an energy storage unit, and the plurality of tenth power conversion subunits are configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply 220.

[0249] Specifically, the plurality of tenth power conversion subunits are respectively the tenth power conversion subunit F1,..., the tenth power conversion subunit F n-1 , the tenth power conversion subunit F n , wherein, the tenth power conversion subunit F1 is respectively connected to the second external power supply 220 and the energy storage unit A1,..., the tenth power conversion subunit F n-1 is respectively connected to the second external power supply 220 and the energy storage unit A n-1 , and the tenth power conversion subunit F n is respectively connected to the second external power supply 220 and the energy storage unit A n . Each tenth power conversion subunit can charge the corresponding energy storage unit based on the first alternating current provided by the second external power supply 220.

[0250] Exemplarily, the second external power supply 220 is a three-phase alternating current power supply, there are three tenth power conversion subunits, and each tenth power conversion subunit is a unidirectional single-phase ACDC subunit or a bidirectional single-phase ACDC subunit. At this time, each tenth power conversion subunit is connected to one phase of the three-phase alternating current power supply to charge the corresponding energy storage unit. When the tenth power conversion subunit is a bidirectional single-phase ACDC subunit, not only can the energy storage module 110 be charged, but also the electric energy of the energy storage module 110 can be fed to the alternating current power grid. And when feeding, the three bidirectional single-phase ACDC subunits cooperate with each other to form three-phase alternating current and feed it to the three-phase alternating current power grid. In this way, in the three-phase alternating current, a single phase is realized by the energy storage unit, and the three energy storage units can realize the function of three-phase alternating current. The specific circuit structure of the unidirectional single-phase ACDC subunit or the bidirectional single-phase ACDC subunit is not limited here.

[0251] It should be noted that in this example, the maximum output power and the rated output power of the input module 130 are also the sum of the maximum output power and the rated output power of the plurality of tenth power conversion subunits.

[0252] In the above embodiments, when the external power supply provides alternating current, the battery subunit can be charged through the plurality of tenth power conversion subunits.

[0253] In some embodiments, referring to Figure 13 , the charging device 100 further includes a wireless communication module 140. At least part of the energy storage module 110, the input module 130, and the charging module 120 is connected to the wireless communication module 140 to perform information interaction with an external device through the wireless communication module 140.

[0254] It should be noted that in the above embodiments, multiple charging device architectures are provided. For example, multiple energy storage units can be connected in series, in parallel, or in series-parallel; some or all of the multiple energy storage units can be provided with a first power conversion subunit, a first switch subunit, or a first power conversion subunit and a first switch subunit; the charging module can adopt a unipolar power conversion subunit or a bipolar power conversion subunit, and the negative input terminals of the corresponding charging piles can be shared or not shared; single-phase in three-phase alternating current is implemented by an energy storage unit, and three energy storage units can implement the function of three-phase alternating current; the input module can be an AC input or a DC input; and so on.

[0255] To enable those skilled in the art to understand the present application more clearly, specific examples are described below, but this should not be construed as a limitation to the present application.

[0256] Example 1, referring to Figure 14 , the energy storage module 110 includes multiple energy storage units. Each energy storage unit includes a battery subunit and a first power conversion subunit. The first power conversion subunit can be a bidirectional DCDC subunit. The multiple energy storage units are connected in series between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110, and the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 are connected to the DC bus, that is, the multiple energy storage units are connected in series and then connected to the DC bus. The charging module 120 includes a third power conversion subunit 121 and a charging gun 122. The third power conversion subunit 121 has a high-voltage positive input terminal, a high-voltage negative input terminal, a high-voltage positive output terminal, and a high-voltage negative output terminal. The third power conversion subunit 121 can be a bipolar bidirectional DCDC subunit. The input module 130 includes a second power conversion subunit 131. The second power conversion subunit 131 can be a bidirectional ACDC subunit. The second external power supply 220 includes a first transformer connected to the AC grid.

[0257] When charging the energy storage module 110, the first transformer converts the second alternating current provided by the AC grid into the first alternating current, converts it into direct current through the bidirectional ACDC subunit, and then charges each battery subunit in the energy storage module 110 through the DC bus.

[0258] When charging a device to be charged, the energy storage unit provides a second direct current based on the electrical energy of the battery subunit. The energy storage module 110 obtains a first direct current based on the second direct current. The first direct current is converted by the high-power bipolar bidirectional DCDC subunit to obtain a fourth direct current, and is charged to the device to be charged through the charging gun 122 to achieve high-power charging, and further achieve fast charging / supercharging of the device to be charged.

[0259] It can be understood that under the action of the bidirectional ACDC subunit and the bipolar bidirectional DCDC subunit, the electrical energy of the device to be charged can also be fed to the energy storage module 110 or the AC power grid, so as to realize the free switching of electrical energy among the device to be charged, the energy storage module 110 and the AC power grid.

[0260] Example 2, refer to Figure 15 , this example compared with Figure 14 The example shown, the difference is that: the fourth power conversion subunit 123 only has a high-voltage positive input terminal and a high-voltage positive output terminal, and the high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit. For the same content, to avoid redundancy, it will not be elaborated here.

[0261] Example 3, refer to Figure 16 , this example compared with Figure 14 The example shown, the difference is that: multiple energy storage units are connected in parallel between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110, that is, multiple energy storage units are connected in parallel to the DC bus.

[0262] Example 4, refer to Figure 17 , this example compared with Figure 16 The example shown, the difference is that: the fourth power conversion subunit 123 only has a high-voltage positive input terminal and a high-voltage positive output terminal, and the high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit.

[0263] Example 5, refer to Figure 18 , this example compared with Figure 14 The example shown, the difference is that: some of the multiple energy storage units include battery subunits, and the other part of the energy storage units include battery subunits and the first power conversion subunit. For example, the energy storage unit A1 includes a battery subunit, and the energy storage unit A n Includes a battery subunit and a bidirectional DCDC subunit A n .

[0264] Example 6, refer toFigure 19 , compared with the example Figure 18 shown, the difference is that: the fourth power conversion subunit 123 only has a high-voltage positive input terminal and a high-voltage positive output terminal, the high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 share the same connection, and the fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit.

[0265] Example Seven, referring to Figure 20 , compared with the example Figure 16 shown, the difference is that: each energy storage unit includes a battery subunit and a first switch subunit, and the first switch subunit can be a protection switch to protect the energy storage unit in case of an abnormality.

[0266] In the above Examples One to Seven, the energy storage module 110 and the charging module 120 are both connected to the DC bus, that is, the charging device 100 adopts a DC bus design. When both the energy storage module 110 and the charging module 120 are set to multiple, multiple charging devices 100 share the DC bus. When the charging device 100 adopts a DC bus design, when the maximum charging output power of the charging device 100 is greater than or equal to 350 kW, the maximum output power of the battery subunit is greater than or equal to 350 kW, the rated power of the battery subunit is greater than or equal to 350 kW, the rated energy of the battery subunit is greater than or equal to 58 kWh, the maximum discharge rate of the battery subunit is greater than or equal to 4C, the maximum output power of the first power conversion subunit is greater than or equal to 350 kW, and the rated power of the first power conversion subunit is greater than or equal to 310 kW. The maximum output power of the input module 130 is less than or equal to 150 kW, and the ratio of the maximum output power of the input module 130 to the maximum output power of the first power conversion subunit is not greater than 1:4.

[0267] Example Eight, referring to Figure 21 , the energy storage module 110 includes three energy storage units A1, A2, and A3 and a selection unit 111. Each energy storage unit includes a battery subunit, and the selection unit 111 includes three second switch subunits K1, K2, and K3. The charging module 120 includes a fifth power conversion subunit 124 and a charging gun 122. The fifth power conversion subunit 124 has a high-voltage positive input terminal, a high-voltage negative input terminal, a high-voltage positive output terminal, and a high-voltage negative output terminal, and the fifth power conversion subunit 124 can be a bipolar bidirectional DCDC subunit. The input module 130 includes three tenth power conversion subunits, and the tenth power conversion subunit can be a bidirectional single-phase ACDC subunit. The second external power supply 220 includes a second transformer connected to the AC power grid.

[0268] When charging the energy storage module 110, the second transformer converts the second alternating current provided by the AC power grid into the first alternating current, which is converted into direct current by the bidirectional single-phase ACDC sub-unit and then used to charge the corresponding battery sub-unit. Each bidirectional single-phase ACDC sub-unit is connected to one phase of the AC bus. For example, the first bidirectional single-phase ACDC sub-unit is connected to phase A, the second bidirectional single-phase ACDC sub-unit is connected to phase B, and the third bidirectional single-phase ACDC sub-unit is connected to phase C. It should be noted that under the action of the bidirectional single-phase ACDC sub-unit, when the electric energy in the energy storage module 110 is fed to the AC power grid, the three bidirectional single-phase ACDC sub-units can cooperate with each other to generate three-phase alternating current with a phase difference of 120°, so that the output of three-phase alternating current can be realized through three energy storage units.

[0269] When charging a device to be charged, the energy storage unit provides the second direct current based on the electric energy of the battery sub-unit. The energy storage module 110 selectively outputs the second direct current through the selection unit 111 to obtain the first direct current. The first direct current is converted into the fourth direct current by the high-power bipolar bidirectional DCDC sub-unit and is used to charge the device to be charged through the charging gun 122 to achieve high-power charging, and further achieve fast charging / supercharging of the device to be charged. In some examples, the second switch sub-units K1, K2, and K3 can be separately closed sequentially in time sharing to make the electric quantities in the three energy storage units consistent.

[0270] It can be understood that under the action of the bidirectional single-phase ACDC sub-unit and the bipolar bidirectional DCDC sub-unit, the electric energy of the device to be charged can also be fed to the energy storage module 110 or the AC power grid, so as to realize the free switching of electric energy among the device to be charged, the energy storage module 110, and the AC power grid.

[0271] Example Nine, referring to Figure 22 This example is different from the example shown in Figure 21 in that the sixth power conversion sub-unit 125 only has a high-voltage positive input terminal and a high-voltage positive output terminal. The high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared. The sixth power conversion sub-unit 125 can be a unipolar bidirectional DCDC sub-unit.

[0272] In the above Examples Eight to Nine, both the energy storage module 110 and the charging module 120 are connected to the AC bus, that is, the charging device 100 adopts an AC bus design. When multiple energy storage modules 110 and charging modules 120 are provided, multiple charging devices 100 share the AC bus.

[0273] In the above Examples 1 to 9, the charging device 100 can communicate with external devices, including but not limited to cloud services / monitoring platforms, through the wireless communication module 140 to achieve 4G / 5G communication, etc. The cloud service / monitoring platform selects a suitable peak-valley period according to the peak-valley period of the area where the charging device 100 is located and sends it to the charging device 100, and the charging device 100 realizes peak shaving and valley filling. For example, during the peak period of the AC power grid, the AC power grid does not charge the energy storage module 110, and during the low valley period of the AC power grid, the energy storage module 110 is slowly charged through the AC power grid.

[0274] It should be noted that the above Examples 1 to 9 are only illustrative. Based on the inventive concept of the present application, through reasonable settings of the foregoing architecture, they should all be within the protection scope of the present application.

[0275] In order to further illustrate the implementation manner of the scheme that the rated charging output power of the charging module of the present application is greater than or equal to 290 kW, the following will give a detailed description of the battery sub-unit.

[0276] In the present application, each energy storage unit may include a battery sub-unit, the battery sub-unit may include one or more single-cell battery cores, the single-cell battery core may include an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode plate, a negative electrode plate and a separator. The positive electrode plate includes a positive current collector and a positive electrode film layer provided on at least one side of the positive current collector, and the positive electrode film layer includes a positive active material. The negative electrode plate includes a negative current collector and a negative electrode film layer provided on at least one side of the negative current collector, and the negative electrode film layer includes a negative active material. Optionally, the single-cell battery core further includes a housing, and the electrode assembly and the electrolyte are accommodated in the housing. The negative electrode film layer includes at least one layer of film layer, which may adopt a single-layer film layer or at least two layers of film layers. Optionally, the negative electrode film layer includes at least two layers of film layers. Similarly, the positive electrode film layer may adopt a single-layer film layer or at least two layers of film layers. During the charging and discharging process of the single-cell battery core, active ions such as lithium ions are embedded and extracted back and forth between the positive electrode plate and the negative electrode plate, and the electrolyte plays a role in conducting active ions between the positive electrode plate and the negative electrode plate.

[0277] The following will give a specific description of the electrolyte, the positive electrode plate, the negative electrode plate and the separator: [Electrolyte] In some embodiments, the electrolyte includes an electrolyte salt, the electrolyte salt includes lithium hexafluorophosphate, and the concentration of lithium hexafluorophosphate is in the range of 0.5 mol / L - 1.0 mol / L.

[0278] By setting the electrolyte to include lithium hexafluorophosphate at the above concentration, the battery subunit has a high ionic conductivity, thereby improving the charging rate of the charging device. Moreover, it also enables the battery subunit to have high interfacial stability and high thermal stability; lithium hexafluorophosphate has little influence on the severity of thermal runaway, making the battery subunit have an appropriate severity of thermal runaway and a low risk of thermal diffusion, so that the charging device has high reliability when the power output is above 350 kW.

[0279] In some embodiments, the electrolyte further includes an organic solvent, and the organic solvent includes a carbonate solvent.

[0280] Optionally, the carbonate solvent includes one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. Further optionally, the carbonate solvent includes one or more of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate.

[0281] Further optionally, the mass content of the carbonate solvent in the organic solvent is 10% to 70%, and can be one of 30% to 50% or 10% to 30% or 30% to 70%.

[0282] Exemplarily, the mass content of the carbonate solvent in the organic solvent is 10%, 20%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 40%, 45%, 48%, 50%, 55%, 60%, 65%, 70% or a range composed of any two of the above values. The carbonate solvent with the above mass content can further improve the conductivity of the electrolyte at room temperature, which is beneficial to the migration of lithium ions.

[0283] Exemplarily, the carbonate solvent includes one or more of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate, and the mass content of the carbonate solvent is 30% to 50%.

[0284] Adding a carbonate solvent to the electrolyte can improve various performances of the battery subunit. For example, it can improve the charge and discharge efficiency, cycle performance, low-temperature performance, and high-voltage stability of the battery subunit, so that the battery subunit can improve the battery discharge stability when the power output is high.

[0285] In some embodiments, the electrolyte includes an electrolyte salt, the electrolyte salt includes lithium hexafluorophosphate, and the concentration of lithium hexafluorophosphate is in the range of 0.5 mol / L - 1.0 mol / L.

[0286] Exemplarily, the concentration of lithium hexafluorophosphate can be 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L or a range composed of any two of the above values.

[0287] Exemplarily, based on the total mass of the electrolyte, the proportion of lithium hexafluorophosphate can be, but is not limited to, 10%-25%.

[0288] By setting the electrolyte to include lithium hexafluorophosphate at the above concentration, the battery subunit has a high ionic conductivity, thereby improving the charging rate of the charging device 100. Moreover, the battery subunit also has high interfacial stability and high thermal stability; lithium hexafluorophosphate has little influence on the severity of thermal runaway, enabling the battery subunit to have an appropriate severity of thermal runaway and a low risk of thermal diffusion, so that the charging device has high reliability when the power output is above 350 kW.

[0289] In some embodiments, the electrolyte salt further includes a fluorosulfonylimide salt, and the concentration of the fluorosulfonylimide salt is in the range of 0.2 mol / L - 0.5 mol / L.

[0290] The fluorosulfonylimide salt may include one or more of lithium bis(fluorosulfonyl)imide LiFSI and lithium bis(trifluoromethanesulfonyl)imide LiTFSI.

[0291] Optionally, the lithium salt includes lithium bis(fluorosulfonyl)imide LiFSI and lithium hexafluorophosphate LiPF6. The molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.2 mol / L to 0.5 mol / L, and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.5 mol / L to 1.0 mol / L.

[0292] Exemplarily, the molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.4 mol / L to 0.5 mol / L, and lithium hexafluorophosphate LiPF 66 has a molar concentration of 0.7 mol / L.

[0293] Exemplarily, the molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.5 mol / L, and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.5 mol / L.

[0294] Exemplarily, the molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.2 mol / L, and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.8 mol / L.

[0295] Optionally, the ratio of the molar concentration of lithium bis(fluorosulfonyl)imide to the molar concentration of lithium hexafluorophosphate LiPF6 is 0.2 to 1.0, and can be optionally 0.2 to 0.5. Exemplarily, the ratio of the molar concentration of lithium bis(fluorosulfonyl)imide to the molar concentration of lithium hexafluorophosphate LiPF6 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 or a range composed of any two of the above values.

[0296] In the embodiments of the present application, the types and contents of inorganic components / lithium salts in the electrolyte have meanings well-known in the art, and can be detected by devices and methods well-known in the art. For example, reference can be made to the standard JY / T 020-1996 "General Rules for Ion Chromatographic Analysis Methods" to qualitatively or quantitatively analyze the concentration of inorganic components / lithium salts in the electrolyte by ion chromatography analysis method. In the embodiments of the present application, newly prepared electrolyte can be taken as a sample, free electrolyte of a fresh battery can be taken as a sample, or a battery that has been fully discharged (discharged to the lower cut-off voltage so that the charged state of the battery is about 0% SOC) can be disassembled in reverse, and the free electrolyte obtained from the battery can be taken as a sample, and the ion chromatography analysis method is used for detection.

[0297] In the embodiments of the present application, the types and contents of organic components in the electrolyte have meanings well-known in the art, and can be detected by devices and methods well-known in the art. For example, reference can be made to GB / T 9722-2006 "General Rules for Gas Chromatography of Chemical Reagents" to qualitatively and quantitatively analyze the organic components in the electrolyte by gas chromatography. In the embodiments of the present application, newly prepared electrolyte can be taken as a sample, free electrolyte of a fresh battery can be taken as a sample, or a battery that has been fully discharged (discharged to the lower cut-off voltage so that the charged state of the battery is about 0% SOC) can be disassembled in reverse, and the free electrolyte obtained from the battery can be taken as a sample, and the ion chromatography analysis method is used for detection.

[0298] In the embodiments of the present application, after quantitatively and qualitatively detecting each component in the electrolyte, each component is classified, and chain carboxylic ester solvents and carbonate solvents (such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate) are used as the constituent components of the organic solvent. Based on the mass of the organic solvent being 100%, the mass content of each component is calculated.

[0299] Carbonate additives (such as vinylene carbonate, fluoroethylene carbonate), sulfur-containing additives, and lithium salt additives are used as additives for the electrolyte. Based on the mass of the electrolyte being 100%, the mass content of each component is calculated.

[0300] Since the fluorosulfonylimide salt has the characteristics of low viscosity and high ionic conductivity, the electrolyte including the above-mentioned concentration of fluorosulfonylimide salt is beneficial to improving the charging rate of the battery subunit, and thus improving the charging rate of the charging device.

[0301] In some embodiments, the organic solvent includes chain carboxylic ester solvents. Based on the total mass of the solvent, the mass content A of the chain carboxylic ester solvents satisfies: 5% ≤ A ≤ 75%.

[0302] Among them, the chain carboxylic ester solvents include compounds with the following structures:

[0303] Among them, R1 includes at least one of a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 haloalkyl group, and R2 includes a C1-C5 alkyl group and / or a C1-C5 haloalkyl group.

[0304] The mass content of the chain carboxylic acid ester solvent relative to the mass of the organic solvent is greater than or equal to 5% and less than or equal to 75%, optionally greater than or equal to 10% and less than or equal to 75%, optionally 30% to 70%, and optionally 50% to 70%. Exemplarily, the mass content of the chain carboxylic acid ester solvent is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or a range composed of any two of the above values.

[0305] When the mass content of the chain carboxylic acid ester solvent is within the above range, the viscosity of the electrolyte system is relatively small, which is beneficial to the migration of lithium ions.

[0306] The above chain carboxylic acid ester solvent has a high conductivity, which is beneficial to improving the fast charging ability of the single cell.

[0307] Optionally, R1 includes a hydrogen atom, a halogen atom, a C1 to C3 alkyl group, or a C1 to C3 haloalkyl group. Further optionally, R1 includes a hydrogen atom, a halogen atom, a C1 to C2 alkyl group, or a C1 to C2 haloalkyl group.

[0308] Optionally, R2 includes a C1 to C3 alkyl group, or a C1 to C3 haloalkyl group. Further optionally, R2 includes a C1 to C2 alkyl group, or a C1 to C2 haloalkyl group.

[0309] In the above embodiments, the halogen atom includes one or more of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Optionally, the halogen atom includes a fluorine atom.

[0310] In the above embodiments, the haloalkyl group includes one or more of a fluoroalkyl group, a chloroalkyl group, a bromoalkyl group, and an iodoalkyl group. Optionally, the haloalkyl group includes a fluoroalkyl group.

[0311] Exemplarily, the chain carboxylic acid ester solvent includes one or more of the compounds shown in Formula I-1 to Formula I-8.

[0312] In this technical solution, the solvent includes a carboxylic acid ester solvent. In this way, the electrolyte can have a higher ionic conductivity and a relatively low viscosity, which is beneficial to further improving the fast charging performance of the charging device, such as fast charging performance and / or supercharging performance.

[0313] In some embodiments, the conductivity of the electrolyte at room temperature is from 13 mS / cm to 20 mS / cm, optionally from 15 mS / cm to 20 mS / cm. Exemplarily, the conductivity of the electrolyte at room temperature is 13 mS / cm, 13.5 mS / cm, 14 mS / cm, 14.5 mS / cm, 15 mS / cm, 15.5 mS / cm, 16 mS / cm, 16.5 mS / cm, 17 mS / cm, 17.5 mS / cm, 18 mS / cm, 18.5 mS / cm, 19 mS / cm, 19.5 mS / cm, 20 mS / cm or a range composed of any two of the above values.

[0314] When the conductivity of the electrolyte at room temperature, such as 25 °C, is within the above range, the migration rate of lithium ions in the electrolyte is relatively high, which can further reduce the internal resistance of the single cell, thereby reducing heat generation and improving the fast charging performance of the single cell.

[0315] In the embodiments of the present application, the conductivity of the electrolyte at room temperature, such as 25 °C, is the ionic conductivity, and it can be detected by using equipment and methods well known in the art. For example, it can be tested with reference to the industry standard HG-T 4067-2015.

[0316] In some embodiments, the viscosity of the electrolyte at room temperature is from 2.3 mPa·s to 3.5 mPa·s. Exemplarily, the viscosity of the electrolyte is 2.3 mPa·s, 2.4 mPa·s, 2.5 mPa·s, 2.6 mPa·s, 2.7 mPa·s, 2.8 mPa·s, 2.9 mPa·s, 3.0 mPa·s, 3.1 mPa·s, 3.2 mPa·s, 3.3 mPa·s, 3.4 mPa·s, 3.5 mPa·s or a range composed of any two of the above values.

[0317] When the viscosity of the electrolyte at room temperature, such as 25 °C, is within the above range, the migration rate of lithium ions in the electrolyte is relatively high, which can further reduce the internal resistance of the single cell, thereby reducing heat generation and improving the fast charging performance of the single cell.

[0318] In the embodiments of the present application, the viscosity of the electrolyte has the meaning well known in the art and can be detected by using equipment and methods well known in the art. For example, it can be detected in accordance with GB / T10247-2008.

[0319] In some embodiments, the density of the electrolyte at room temperature, such as 25 °C, is from 1.05 g / mL to 1.35 g / mL. Exemplarily, the density of the electrolyte is 1.05 g / mL, 1.10 g / mL, 1.15 g / mL, 1.2 g / mL, 1.25 g / mL, 1.3 g / mL, 1.35 g / mL or a range composed of any two of the above values.

[0320] When the density of the electrolyte is within the above range, the migration rate of lithium ions in the electrolyte is relatively high, which can further reduce the internal resistance of the single cell, thereby reducing heat generation and improving the fast charging performance of the single cell.

[0321] In the embodiments of the present application, the density of the electrolyte has the meaning well known in the art and can be detected by devices and methods well known in the art. For example, it can be tested with reference to GB / T 2013-2010.

[0322] The electrolyte includes an organic solvent and an electrolyte salt. The types of the organic solvent and the electrolyte salt are not specifically limited and can be selected according to actual needs.

[0323] In some embodiments, the electrolyte further contains additives. The additives can include negative electrode film-forming additives, positive electrode film-forming additives, or additives that can improve certain battery performance, such as additives for improving the overcharging performance of the battery, additives for improving the high-temperature performance of the battery, additives for improving the low-temperature power performance of the battery, etc.

[0324] In some embodiments, the additives include one or more of carbonate additives, sulfur-containing additives, and lithium salt additives, and can be selected as at least two. The above additives can improve the interfacial film performance on the positive electrode side and / or the negative electrode side, which is beneficial to improving the fast charging performance of the single cell and improving the cycle performance.

[0325] In some embodiments, the mass content of the additives in the electrolyte is 1% to 10%, optionally 2% to 8%, and further optionally 3.5% to 8%. Exemplarily, the mass content of the additives in the electrolyte is 1%, 2%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or the range composed of any two of the above values.

[0326] The additives with the above mass content can effectively improve the interfacial film performance on the positive electrode side and / or the negative electrode side, which is beneficial to improving the fast charging performance of the single cell and improving the cycle performance.

[0327] Exemplarily, the carbonate additives include one or more of vinylene carbonate VC and fluoroethylene carbonate FEC.

[0328] Exemplarily, the sulfur-containing additives include one or more of ethylene sulfate DTD, bis(ethylene sulfate) 2-DTD, butene sulfite BS, 1,3-propane sultone PS, ethylene sulfite ES, and methylene methanedisulfonate MMDS.

[0329] Optionally, the lithium salt additive includes one or more of lithium difluorophosphate (LiPO2F2), lithium difluorooxalate borate (LiDFOB), lithium tetrafluoroborate (LiBF4), and lithium bis(oxalate)borate (LiBOB).

[0330] Optionally, the mass content of vinylene carbonate (VC) in the electrolyte is 0.5% to 9%, and can be optionally 2% to 6%.

[0331] Optionally, the mass content of fluoroethylene carbonate (FEC) in the electrolyte is 0.1% to 4%, and can be optionally 0.5% to 3%.

[0332] Optionally, the mass content of vinylene carbonate (VC) in the electrolyte is 0.5% to 9%, and the mass content of fluoroethylene carbonate (FEC) in the electrolyte is 0.1% to 4%.

[0333] Further optionally, the mass content of vinylene carbonate (VC) in the electrolyte is 2% to 6%, and the mass content of fluoroethylene carbonate (FEC) in the electrolyte is 0.5% to 3%.

[0334] In some embodiments, the single cell satisfies: 2.45 g / Ah ≤ d / A ≤ 3.5 g / Ah, and can be optionally 2.45 g / Ah ≤ d / A ≤ 3.3 g / Ah, where d represents the mass of the electrolyte in the single cell, in g, and A represents the rated capacity of the single cell, in Ah. Exemplarily, d / A can be 3.5 g / Ah, 3.3 g / Ah, 3.2 g / Ah, 3.0 g / Ah, 2.8 g / Ah, 2.5 g / Ah, 2.45 g / Ah or a range composed of any two of the above values.

[0335] d / A can reflect the liquid retention ability of the electrolyte. When d / A is within the above range, the electrolyte can play a good wetting role on the positive electrode plate and the negative electrode plate, and can also improve the migration rate of lithium ions in the liquid phase, which is beneficial to improving the fast charging ability of the single cell.

[0336] In the embodiments of the present application, d / A of the single cell can be understood as the liquid retention coefficient, and can be detected by using the equipment and methods well-known in the art. For example, taking the upper limit voltage of battery charging as 3.65 V and the cut-off voltage of battery discharging as 2.0 V as an example in accordance with GB / T31486-2015 "Performance Requirements and Test Methods for Power Batteries for Electric Vehicles".

[0337] At 25°C, the single-cell battery is charged at 0.33C to 3.65V, then charged at a constant voltage until 0.05C, and then discharged at a constant current of 0.33C to 2.0V. The discharged capacity A is used as the denominator. The single-cell battery is weighed as M0, and then the positive electrode sheet, negative electrode sheet, separator, and electrolyte are disassembled. The free electrolyte is stored in a bag. All the above solid components are placed in an oven at 60°C and baked for more than 4 hours (including but not limited to the positive electrode sheet, negative electrode sheet, and separator, and also including other mechanical components of the disassembled single-cell battery that contribute to M0). Then, all the components of the single-cell battery are weighed as M1. The weight difference between M0 and M1 is used as the numerator. The liquid retention coefficient is equal to the value obtained by dividing the weight difference d between M0 and M1 by the capacity A.

[0338] [Negative electrode sheet] In some embodiments, the resistance value of the negative electrode sheet can be, but is not limited to, in the range of 0.001Ω - 0.01Ω.

[0339] It can be optionally 0.001Ω to 0.005Ω. Exemplarily, the resistance of the negative electrode sheet is 0.001Ω, 0.002Ω, 0.003Ω, 0.004Ω, 0.005Ω, 0.006Ω, 0.007Ω, 0.008Ω, 0.009Ω, 0.01Ω or the range composed of any two of the above values.

[0340] In other examples, the resistance of the negative electrode sheet can be in the range of 1mΩ - 50mΩ.

[0341] Thus, when the resistance of the negative electrode sheet is within the above range, it is beneficial to reduce the internal resistance of the single-cell battery, improve the conductivity of the battery subunit, and then improve the charging rate of the battery subunit, which is beneficial to enhancing the fast charging performance of the battery device.

[0342] In the embodiments of the present application, the resistance of the negative electrode sheet has the meaning well-known in the art and can be detected by the equipment and methods well-known in the art. The detection method is the same as the resistance test method of the positive electrode sheet described above.

[0343] In some embodiments, the negative electrode active material includes a carbon-based material, and the carbon-based material includes at least one of natural graphite and artificial graphite. Or the carbon-based material can also include natural graphite. Specifically, the carbon-based material can include graphite particles, or the carbon-based material can include graphite particles and natural graphite.

[0344] Optionally, the carbon-based material is graphite particles. Based on the mass of the graphite particles, the mass ratio of natural graphite can be greater than that of artificial graphite.

[0345] At least one of natural graphite and artificial graphite is used as the carbon-based material of the negative electrode active material layer, and both have good electrical conductivity and a relatively high theoretical specific capacity. Natural graphite has a high crystallinity and a regular layered structure, which is beneficial to the rapid insertion and extraction of lithium ions, thereby improving the charge and discharge efficiency of the battery; artificial graphite can precisely adjust its microstructure and performance by controlling the production process, enhance the cycle stability of a single cell, and extend the service life of a single cell. Therefore, in the scenario of high-power charging, the cycle life and charging stability of the charging device 100 can be extended.

[0346] In some embodiments, the volume average particle size Dv50 of the negative electrode film layer can be, but is not limited to, in the range of 8.2 μm - 13.5 μm.

[0347] When the negative electrode film layer adopts a single-layer film layer, the negative electrode active material in the negative electrode film layer includes a carbon-based material, and optionally also includes a silicon-based material. When a single-layer film layer is adopted, the volume average particle size Dv50 of the negative electrode active material can be, but is not limited to, 8.2 μm to 13.5 μm. Exemplarily, the volume average particle size Dv50 of the negative electrode active material is 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm or a range composed of any two of the above values. In other embodiments, the volume average particle size Dv50 of the negative electrode film layer can be between 8.2 μm - 18.5 μm. For example, it can be 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm, 14 μm, 15 μm, 16.2 μm, 18 μm, 18.5 μm or a range composed of any two of the above values.

[0348] When the negative electrode film layer adopts at least two-layer film layers, the negative electrode active material in the negative electrode film layer includes a carbon-based material, and optionally also includes a silicon-based material. The silicon-based material can be located in one of the at least two-layer film layers, or can be located in at least two of the at least two-layer film layers. The negative electrode film layer can include two-layer film layers, three-layer film layers, four-layer film layers, or even more film layers.

[0349] The volume average particle size Dv50 of the negative electrode film layer is in the range of 8.2 μm to 13.5 μm. This particle size range can balance the specific surface area and the tap density. A smaller particle size can provide a larger specific surface area, increasing the reaction sites for lithium ions and improving the charge-discharge rate performance of the single-cell battery. An appropriate particle size can have a higher tap density, reducing the voids between the active materials and increasing the energy density of the single-cell battery. Thus, the single-cell battery can achieve a better balance in rate performance and energy density to meet the charging requirements of the charging device 100 at different charging rates.

[0350] In some embodiments, the negative electrode film layer includes a first negative electrode active material layer and a second negative electrode active material layer arranged in a stacked manner. The first negative electrode active material layer is located on the side closer to the negative electrode current collector. The volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer is 9.5 μm to 18.5 μm, and the volume average particle size Dv50 of the negative electrode active material in the second negative electrode active material layer is 7.8 μm to 14.3 μm.

[0351] When the volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer and the volume average particle size Dv50 of the negative electrode active material in the second negative electrode active material layer are within the above ranges, on the one hand, it can shorten the solid-phase transmission path of lithium ions and improve the fast charging performance. On the other hand, the material is not prone to agglomeration during the preparation process, which can improve the stability of the material. The cooperation of the negative electrode active material in the second negative electrode active material layer and the negative electrode active material in the first negative electrode active material layer within the above volume average particle size range is beneficial to constructing the gradient pore difference between the second negative electrode active material layer and the first negative electrode active material layer, reducing the tortuosity of lithium ion transmission, and improving the fast charging performance of the battery single cell.

[0352] In some embodiments, the negative electrode film layer includes a first negative electrode film layer and a second negative electrode film layer. The first negative electrode film layer is disposed on the surface of the negative electrode current collector. The carbon-based material in the first negative electrode film layer includes graphite particles. The second negative electrode film layer is connected to the side of the first negative electrode film layer facing away from the negative electrode current collector. The carbon-based material in the second negative electrode film layer includes graphite particles. The graphite particles in the first negative electrode film layer and the graphite particles in the second negative electrode film layer can be the same or different.

[0353] The interface between the first negative electrode film layer and the second negative electrode film layer can be regular or irregular, and is optionally irregular.

[0354] Optionally, the carbon-based material in the first negative electrode film layer further includes natural graphite.

[0355] The negative electrode film layer includes at least two film layers, and layered coating is beneficial to improving the fast charging performance of the single cell. Especially when there are differences between the first negative electrode film layer and the second negative electrode film layer, it is possible to construct pore differences in the negative electrode film layer, reduce the tortuosity of lithium ion transport, and improve the fast charging performance of the single cell.

[0356] Optionally, the volume average particle size Dv50 of the negative electrode active material in the first negative electrode film layer is greater than or equal to the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film layer. Further optionally, the volume average particle size Dv50 of the negative electrode active material in the first negative electrode film layer is greater than the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film layer, which is beneficial to improving the tap density of the negative electrode film layer. When the negative electrode active material includes graphite particles, the volume average particle size Dv50 of the graphite particles in the first negative electrode film layer is greater than or equal to the volume average particle size Dv50 of the graphite particles in the second negative electrode film layer.

[0357] There are differences in the particle sizes of the first negative electrode film layer and the second negative electrode film layer, which can improve the fast charging performance of the single cell. Specifically, during fast charging, the overpotential of the second negative electrode film layer is usually higher, and the bottleneck of fast charging lies mainly in the second negative electrode film layer. In the embodiments of the present application, the particle size in the second negative electrode film layer is relatively small, which can shorten the solid-phase transport path of lithium ions, improve the fast charging performance, and can improve the problem of lithium deposition on the surface layer of the negative electrode sheet.

[0358] Optionally, the negative electrode active material in the first negative electrode film layer is granular, and its volume average particle size Dv50 is from 9.5 μm to 18.5 μm, and can be from 9.5 μm to 14.6 μm. Exemplarily, the volume average particle size of the negative electrode active material in the first negative electrode film layer is 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 14.6 μm, 15 μm, 15.5 μm, 16 μm, 16.5 μm, 17 μm, 17.5 μm, 18 μm, 18.5 μm or the range composed of any two of the above values. When the first negative electrode film layer includes graphite particles, the volume average particle size Dv50 of the graphite particles in the first negative electrode film layer is from 9.5 μm to 18.5 μm, and can be from 9.5 μm to 14.6 μm.

[0359] When the volume average particle size Dv50 of the negative electrode active material in the first negative electrode film layer is within the above range, on the one hand, it can shorten the solid-phase transport path of lithium ions and improve the fast charging performance. On the other hand, the material is not prone to agglomeration during the preparation process, which can improve the stability of the material.

[0360] Optionally, the negative electrode active material in the second negative electrode film layer is granular, and its volume average particle size Dv50 is from 7.8 μm to 14.3 μm, optionally from 7.8 μm to 11.3 μm. Exemplarily, the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film layer is 7.8 μm, 8.0 μm, 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.3 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm, 13.8 μm, 14 μm, 14.1 μm, 14.3 μm or a range composed of any two of the above values. When the second negative electrode film layer includes graphite particles, the volume average particle size Dv50 of the graphite particles in the second negative electrode film layer is from 7.8 μm to 14.3 μm, optionally from 7.8 μm to 11.3 μm.

[0361] When the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film layer is within the above range, on the one hand, it can shorten the solid-phase transmission path of lithium ions and improve the fast charging performance. On the other hand, the material is not prone to agglomeration during the preparation process, which can improve the stability of the material. On the other hand, the negative electrode active material in the second negative electrode film layer with the above volume average particle size range cooperates with the negative electrode active material in the first negative electrode film layer, which is beneficial to constructing the gradient pore difference between the second negative electrode film layer and the first negative electrode film layer, reducing the tortuosity of lithium ion transmission, and improving the fast charging performance of the single cell.

[0362] In the embodiments of the present application, the volume average particle size Dv50 of the negative electrode active material has the meaning well-known in the art and can be detected by using the equipment and methods well-known in the art. Its detection method is the same as the test method for the volume average particle size Dv50 of the positive electrode active material described above.

[0363] Optionally, the tapped density of the carbon-based material in the first negative electrode film layer is less than or equal to the tapped density of the carbon-based material in the second negative electrode film layer. The tapped density can reflect the filling density of the active material in the film layer. When the tapped density of the carbon-based material in the second negative electrode film layer is greater than the tapped density of the carbon-based material in the first negative electrode film layer, the second negative electrode film layer is filled more densely, so that the energy density of the single cell is improved. The filling of the first negative electrode film layer is relatively sparse and the pores are richer, which can improve the fast charging performance of the single cell. When the negative electrode active material includes graphite particles, the tapped density of the graphite particles in the first negative electrode film layer is less than or equal to the tapped density of the graphite particles in the second negative electrode film layer.

[0364] Optionally, the tapped density of the carbon-based material in the first negative electrode film layer is 0.82 g / cm 3To 1.21 g / cm 3 , such as 0.82 g / cm 3 , 0.85 g / cm 3 , 0.88 g / cm 3 , 0.90 g / cm 3 , 0.92 g / cm 3 , 0.95 g / cm 3 , 0.98 g / cm 3 , 1.00 g / cm 3 , 1.05 g / cm 3 , 1.08 g / cm 3 , 1.10 g / cm 3 , 1.12 g / cm 3 , 1.15 g / cm 3 , 1.18 g / cm 3 , 1.20 g / cm 3 , 1.21 g / cm 3 or a range composed of any two of the above values. When the tap density of the carbon-based material in the first negative electrode film layer is within a suitable range, the fast charging performance of the single cell can be improved.

[0365] Optionally, the tap density of the carbon-based material in the second negative electrode film layer is 0.90 g / cm 3 to 1.25 g / cm 3 , such as 0.90 g / cm 3 , 0.92 g / cm 3 , 0.95 g / cm 3 , 0.98 g / cm 3 , 1.00 g / cm 3 , 1.05 g / cm 3 , 1.08 g / cm 3 , 1.10 g / cm 3 , 1.12 g / cm 3 , 1.15 g / cm 3 , 1.18 g / cm 3 , 1.20 g / cm 3 , 1.21 g / cm 3 , 1.22 g / cm 3 , 1.23 g / cm 3 , 1.24 g / cm 3 ³ , 1.25 g / cm 3 or a range composed of any two of the above values. When the tap density of the carbon-based material in the second negative electrode film layer is within a suitable range, the energy density of the single cell can be improved.

[0366] In the embodiments of the present application, the tapped density of the material has the meaning well-known in the art and can be measured by instruments and methods known in the art. For example, reference can be made to GB / T5162-2006 and a powder tapped density tester can be used for measurement. The test instrument can be BT-301 produced by Dandong BETOP.

[0367] Optionally, the ratio of the thickness of the second negative electrode film layer to the thickness of the first negative electrode film layer is from 3:7 to 7:3, and can be optionally from 4:6 to 6:4. Exemplarily, the ratio of the thickness of the second negative electrode film layer to the thickness of the first negative electrode film layer is 3:7, 4:6, 5:5, 6:4, 7:3 or a range composed of any two of the above values. By adjusting the thickness ratio of the first negative electrode film layer and the second negative electrode film layer, the gradient pore difference between the upper and lower layers can be further increased, the tortuosity of lithium ion transmission can be reduced, and the fast charging ability of the single cell can be improved.

[0368] In some embodiments, when the single cell is in a 100% charged state, the tap density of the negative electrode film layer is 1.15 g / cm 3 - 1.36 g / cm 3 .

[0369] It can be optionally 1.25 g / cm 3 to 1.36 g / cm 3 . Exemplarily, when the single cell is in a 100% charged state, the tap density of the negative electrode film layer is 1.15 g / cm 3 , 1.18 g / cm 3 , 1.20 g / cm 3 , 1.22 g / cm 3 , 1.25 g / cm 3 , 1.28 g / cm 3 , 1.3 g / cm 3 , 1.32 g / cm 3 , 1.35 g / cm 3 , 1.36 g / cm 3 or a range composed of any two of the above values.

[0370] In the embodiments of the present application, when the single cell is in a 100% charged state, the tap density of the negative electrode film layer has the meaning well-known in the art and can be detected by equipment and methods well-known in the art. The detection method is the same as the tap density test method of the positive electrode film layer described above.

[0371] When the tap density of the negative electrode film layer is within the above range, it is beneficial to improve the energy density of the battery single cell, and since the negative active materials in the negative electrode film layer are stacked relatively tightly and the contact resistance between particles is small, the resistance of the electrode sheet can be further reduced, thereby reducing heat generation.

[0372] In some embodiments, the powder compaction density of the negative electrode active material under a pressure of 20,000 N is 1.5 g / cm 3 to 1.85 g / cm 3 , optionally 1.55 g / cm 3 to 1.65 g / cm 3 . Exemplarily, the powder compaction density of the negative electrode active material under a pressure of 20,000 N is 1.5 g / cm 3 , 1.55 g / cm 3 , 1.6 g / cm 3 , 1.65 g / cm 3 , 1.7 g / cm 3 , 1.75 g / cm 3 , 1.8 g / cm 3³ , 1.85 g / cm 3 or a range composed of any two of the above values.

[0373] When the powder compaction density of the negative electrode active material under 20,000 N is within the above range, the energy density of the single cell can be improved, and since the negative electrode active material in the negative electrode film layer can be stacked more closely, the contact resistance between particles is small, the resistance of the electrode sheet can be further reduced, thereby reducing heat generation.

[0374] In the embodiments of the present application, the powder compaction density of the material has the meaning well known in the art, and can be detected by the methods and equipment well known in the art, and detected according to the test standard GB / T24533-2009. As an example, a certain amount of negative electrode active material is taken as a sample and added to a mold with a bottom area of 1.327 cm 2² in a UTM7305 type electronic pressure testing machine, pressurized to 2000 kg (equivalent to 20,000 N), held for 30 s, then depressurized, held for 10 s, and then the powder compaction density of the negative electrode active material under a force of 20,000 N is recorded and calculated.

[0375] In some embodiments, the charging specific capacity of the negative electrode active material at a rate of 0.1 C is 350 mAh / g to 480 mAh / g. Exemplarily, the charging specific capacity of the negative electrode active material at a rate of 0.1 C is 350 mAh / g, 355 mAh / g, 360 mAh / g, 365 mAh / g, 370 mAh / g, 375 mAh / g, 380 mAh / g, 385 mAh / g, 390 mAh / g, 395 mAh / g, 400 mAh / g, 410 mAh / g, 420 mAh / g, 430 mAh / g, 440 mAh / g, 450 mAh / g, 460 mAh / g, 470 mAh / g, 480 mAh / g or a range composed of any two of the above values.

[0376] When the charging specific capacity of the negative electrode active material at a rate of 0.1C is within the above range, the energy density of the single cell is relatively high.

[0377] In the embodiments of the present application, the charging specific capacity of the negative electrode active material at a rate of 0.1C has the meaning well-known in the art, and can be detected by the equipment and methods well-known in the art. The detection method is the same as the charging specific capacity test method of the positive electrode active material at a rate of 0.1C described above.

[0378] In some embodiments, the negative electrode active material layer includes a carbon-based material, and the carbon-based material has high cycle stability and can improve the cycle performance of the single cell. Optionally, the mass ratio of the carbon-based material in the negative electrode active material can be greater than or equal to 80% and less than or equal to 100%.

[0379] The positive electrode active material of the present application is mainly a lithium-containing phosphate system with an olivine structure, and the negative electrode active material is mainly a carbon-based material system. When the two are used in combination, the cycle performance of the single cell is relatively excellent.

[0380] Optionally, the carbon-based material includes graphite particles, and the graphitization degree of the graphite particles is 92.0% to 94.5%. Exemplarily, the graphitization degree of the graphite particles is 92.0%, 92.5%, 93%, 93.5%, 94%, 94.5% or the range composed of any two of the above values.

[0381] When the graphitization degree of the graphite particles is within the above range, the conductive performance of the graphite particles is relatively excellent, which can reduce the heat generation of the negative electrode plate and the single cell, and can improve the fast charging performance of the single cell.

[0382] In some embodiments, the graphite particles include artificial graphite and a carbon coating layer. The artificial graphite includes secondary particles, and the secondary particles include a plurality of primary particles. The carbon coating layer covers the surface of the artificial graphite. The carbon in the carbon coating layer is mainly amorphous carbon. Amorphous carbon refers to a transition carbon material with a very low degree of graphitization crystallization and an approximate amorphous form (or no fixed shape and periodic structural rules). In the present application, amorphous carbon refers to the product after carbonization treatment of an organic carbon source.

[0383] The artificial graphite includes secondary particles. In the artificial graphite, there are more migration paths for lithium ions, and the migration path in the primary particles is shorter, which can improve the migration rate of lithium ions. The carbon coating layer has more end faces and defects, which increases the number of sites where lithium ions can be intercalated and deintercalated, making the conductivity of the carbon coating layer relatively excellent, and can reduce the internal resistance of the negative electrode plate and the heat generation of the single cell.

[0384] Optionally, based on the mass of the graphite particles, the mass content of the carbon coating layer is 2% to 5%. Exemplarily, the mass content of the carbon coating layer is 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% or a range composed of any two of the above values.

[0385] When the mass content of the carbon coating layer is within the above range, the internal resistance of the negative electrode sheet can be further reduced, and the heat generation of the single cell can be reduced.

[0386] In the embodiments of the present application, the graphite particles can be prepared by methods well-known in the art. For example, the preparation method includes: providing artificial graphite and an organic carbon source, mixing the two, and after carbonization treatment, forming a carbon coating layer on at least a part of the surface of the artificial graphite particles.

[0387] Optionally, the organic carbon source includes one or more of coal tar pitch, petroleum pitch, phenolic resin, and coconut shell. Further optionally, the organic carbon source includes petroleum pitch. Optionally, the softening point of the coal tar pitch and petroleum pitch is below 250 °C.

[0388] Optionally, the carbonization treatment temperature is 700 °C to 1800 °C. Optionally, the carbonization treatment temperature is 1000 °C to 1300 °C. When the carbonization treatment temperature is within a suitable range, the organic carbon source can be carbonized, and a coating layer containing amorphous carbon can be formed on at least a part of the surface of the artificial graphite.

[0389] Optionally, the carbonization treatment time is 1 h to 6 h.

[0390] In some embodiments, the negative electrode active material may further include a silicon-based material. The introduction of the silicon-based material can increase the capacity of the negative electrode active material and improve the energy density of the single cell.

[0391] Optionally, based on the mass of the negative electrode active material, the mass content of silicon element in the silicon-based material is 0.3% to 10.0%, and can be selected as 1% to 6%. Exemplarily, the mass content of silicon element in the silicon-based material is 0.3%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, 8%, 8.2%, 8.5%, 8.8%, 9%, 9.2%, 9.5%, 9.8%, 10% or a range composed of any two of the above values.

[0392] When the mass content of silicon element in the silicon-based material is within the above range, the capacity of the negative electrode active material can be increased, and the energy density of the single cell can be improved.

[0393] Optionally, the silicon-based material may include at least one of elemental silicon, silicon oxide, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy material.

[0394] In some embodiments, in addition to the above-mentioned carbon-based material and optional silicon-based material, the negative electrode active material may further include at least one of a tin-based material and lithium titanate. The tin-based material may include at least one of elemental tin, tin oxide, and tin alloy material.

[0395] In the present application, the qualitative and quantitative determination of each substance or element can be detected by suitable equipment and methods known to those skilled in the art. Relevant detection methods can refer to domestic and foreign detection standards, domestic and foreign enterprise standards, etc. And those skilled in the art can also adaptively change certain detection steps / instrument parameters, etc. from the perspective of detection accuracy to obtain more accurate detection results. One detection method can be used for qualitative or quantitative determination, or several detection methods can be used in combination for qualitative or quantitative determination.

[0396] For example, the present application can perform X-ray powder diffraction testing and qualitative analysis on the negative electrode sheet or the negative electrode active material in combination with the General Rules for X-ray Diffraction Analysis JIS / K0131-1996.

[0397] Artificial graphite and natural graphite can be distinguished by the SEM cross-sectional view taken by scanning electron microscope (SEM). In the SEM cross-sectional view of natural graphite, there are voids between flaky structures. The SEM cross-sectional view of artificial graphite is dense and has no obvious gaps, or can be distinguished by the XRD spectrum obtained by X-ray diffraction method. In the XRD spectrum of natural graphite, obvious 2H phase and 3R phase exist, and only 2H phase exists in the XRD spectrum of artificial graphite.

[0398] In some embodiments, the powder resistivity of the negative electrode active material is from 0.005 Ω·cm to 0.043 Ω·cm, and can be optionally 0.04 Ω·cm. Exemplarily, the powder resistivity of the negative electrode active material can be 0.043 Ω·cm, 0.04 Ω·cm, 0.035 Ω·cm, 0.03 Ω·cm, 0.025 Ω·cm, 0.02 Ω·cm, 0.015 Ω·cm, 0.01 Ω·cm, 0.005 Ω·cm or the range composed of any two of the above values.

[0399] The relatively low powder resistivity of the negative electrode active material results in a relatively low resistance of the negative electrode sheet and less heat generation of the single cell.

[0400] In the embodiments of the present application, the powder resistivity of the negative electrode active material has the meaning well-known in the art and can be detected by the equipment and methods well-known in the art. Its detection method is the same as the powder resistivity test method of the positive electrode active material described above.

[0401] In some embodiments, after the monomer cell undergoes 10 full charge test cycles at the beginning of life (BOL), the thickness of the first negative electrode film layer is 15 μm to 65 μm, such as 15 μm, 17 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 57 μm, 58 μm, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm, 65 μm, or a range composed of any two of the above values. When the thickness of the first negative electrode film layer is within the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transport can be reduced, and the fast charging ability of the monomer cell can be improved.

[0402] In some embodiments, after the monomer cell undergoes 10 full charge test cycles at the beginning of life (BOL), the thickness of the second negative electrode film layer is 15 μm to 65 μm, such as 15 μm, 17 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 57 μm, 58 μm, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm, 65 μm, or a range composed of any two of the above values. When the thickness of the second negative electrode film layer is within the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transport can be reduced, and the fast charging ability of the monomer cell can be improved.

[0403] In the embodiments of the present application, for example, taking the upper limit voltage of battery charging as 3.65 V and the cut-off voltage of battery discharging as 2.0 V as an example for illustration, The specific steps of the BOL full charge test are as follows: At 25 °C, charge at a charging rate of 0.33 C of the battery nominal capacity to 3.65 V, then charge at a constant voltage of 3.65 V to 0.05 C, stand for 10 min, then discharge at a discharging rate of 0.33 C to 2.0 V, stand for 10 min. The above one charge and discharge is a cycle, and cycle 10 times. Then charge at a charging rate of 0.33 C of the nominal capacity to 3.65 V, and then charge at a constant voltage of 3.65 V to 0.05 C to obtain the BOL full charge state. In the BOL full charge state, disassemble the negative electrode plate, use a tomography electron microscope to observe the cross-section in the thickness direction of the middle area of the negative electrode plate, distinguish the two regions according to the interface between the first negative electrode film layer and the second negative electrode film layer, and measure the thicknesses of the two respectively. For example, measure the thicknesses of 10 positions of the first negative electrode film layer, calculate their average value as the average thickness of the first negative electrode film layer, measure the thicknesses of 10 positions of the second negative electrode film layer, and calculate their average value as the average thickness of the second negative electrode film layer.

[0404] In some embodiments, after the full charge test at the end of life (EOL) of the single cell, the thickness of the first negative electrode film layer is 15 μm to 70 μm, such as 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 35 μm, 40 μm, 43 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 66 μm, 67 μm, 68 μm, 69 μm, 70 μm or the range composed of any two of the above values. When the thickness of the first negative electrode film layer is within the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transport can be reduced, and the fast charging ability of the single cell can be improved.

[0405] In some embodiments, after the full charge test at the end of life (EOL) of the single cell, the thickness of the second negative electrode film layer is 15 μm to 70 μm, such as 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 35 μm, 40 μm, 43 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 66 μm, 67 μm, 68 μm, 69 μm, 70 μm or the range composed of any two of the above values. When the thickness of the second negative electrode film layer is within the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transport can be reduced, and the fast charging ability of the single cell can be improved.

[0406] In the embodiments of the present application, for example, the upper limit voltage of battery charging is taken as 3.65 V and the cut-off voltage of battery discharging is taken as 2.0 V for illustration.

[0407] The specific steps of the EOL full charge test are as follows: At 60°C, charge at a charging rate of 0.33C of the battery's nominal capacity until 3.65V, then perform constant voltage charging at 3.65V until 0.05C, let it stand for 10 minutes, then discharge at a discharge rate of 0.33C until 2.0V, and let it stand for 10 minutes. The above one charge and discharge cycle is repeated until the battery capacity decays to 80% of the nominal capacity and the test stops. Then, at 25°C, charge at a constant current of 0.33C until 3.65V, and perform constant voltage charging at a rate of 0.05C until 3.65V, which is the EOL full charge state. In the EOL full charge state, disassemble the negative electrode sheet, and use a tomography scanning electron microscope to observe the cross-section in the thickness direction of the middle area of the negative electrode sheet. Distinguish the regions of the first negative electrode film layer and the second negative electrode film layer according to the interface between them, and measure their thicknesses respectively. For example, measure the thicknesses of 10 positions of the first negative electrode film layer, and calculate their average value as the average thickness of the first negative electrode film layer. Measure the thicknesses of 10 positions of the second negative electrode film layer, and calculate their average value as the average thickness of the second negative electrode film layer.

[0408] In some embodiments, when the negative electrode film layer adopts a single-layer film layer (different from the above-mentioned double-layer film layer), the negative electrode film layer further includes a lithium-containing binder. Optionally, the mass content of the lithium-containing binder relative to the mass of the negative electrode film layer is 0.1% to 1%. Exemplarily, the mass content of the lithium-containing binder relative to the mass of the negative electrode film layer is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% or a range composed of any two of the above values. The lithium element in the lithium-containing binder can exist in ionic form, which can increase the number of free-moving lithium ions in the negative electrode film layer, shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, increase the intercalation and deintercalation rate of lithium ions, and improve the fast charging performance of the single-cell battery. Optionally, the negative electrode film layer can further include a negative electrode binder. For example, the negative electrode binder includes at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based acrylic resin (such as polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0409] Optionally, the mass content of lithium element in the lithium-containing binder is 3% to 10%. Exemplarily, the mass content of lithium element in the lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or a range composed of any two of the above values. The mass content of lithium element is calculated based on the mass of the lithium-containing binder. When the mass content of lithium element is within the above range, the number of free-moving lithium ions in the negative electrode film layer can be relatively large, which can further shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, increase the intercalation and deintercalation rate of lithium ions, and improve the fast charging performance of the single-cell battery.

[0410] Exemplarily, the lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-2-hydroxyethyl acrylate copolymer, which is derived from a lithium acrylate monomer, an acrylonitrile monomer, an acrylamide monomer, and a 2-hydroxyethyl acrylate monomer. The molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 2-hydroxyethyl acrylate monomer is 30% to 50%: 15% to 45%: 5% to 20%: 20% to 35%. For example, the molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 2-hydroxyethyl acrylate monomer is 35%: 30%: 15%: 20%, or 40%: 20%: 10%: 30%, or 45%: 15%: 20%: 20%, etc.

[0411] The lithium-containing binder of the above materials can provide a certain number of lithium ions for the negative electrode film layer, improve the fast charging performance of the single-cell battery, and is not prone to swelling during the charge and discharge process, with a stable structure, so that the cycle performance of the negative electrode film layer is improved during the fast charge and discharge process.

[0412] In some other embodiments, when the negative electrode film layer adopts at least two film layers, the negative electrode film layer further includes a lithium-containing binder.

[0413] Optionally, the first negative electrode film layer further includes a first lithium-containing binder, and the second negative electrode film layer further includes a second lithium-containing binder. The mass content of the first lithium-containing binder relative to the mass of the first negative electrode film layer is less than or equal to the mass content of the second lithium-containing binder relative to the mass of the second negative electrode film layer. Further optionally, the mass content of the first lithium-containing binder relative to the mass of the first negative electrode film layer is less than the mass content of the second lithium-containing binder relative to the mass of the second negative electrode film layer.

[0414] The mass content of the second lithium-containing binder in the second negative electrode film layer is relatively high, and the number of freely movable lithium ions provided by the second lithium-containing binder for the second negative electrode film layer is relatively more, which can further improve the fast charging performance of the single-cell battery.

[0415] Optionally, the mass content of the first lithium-containing binder relative to the mass of the first negative electrode film layer is 0.1% to 1%. Exemplarily, the mass content of the first lithium-containing binder relative to the mass of the first negative electrode film layer is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% or a range composed of any two of the above values. The lithium element in the first lithium-containing binder can exist in the form of ions, which can increase the number of freely movable lithium ions in the negative electrode film layer, shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, increase the deintercalation rate of lithium ions, and improve the fast charging performance of the single-cell battery.

[0416] Optionally, the mass content of lithium element in the first lithium-containing binder is 3% to 10%, and can be optionally 3% to 8%. Exemplarily, the mass content of lithium element in the first lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or the range composed of any two of the above values. When the mass content of lithium element is within the above range, the number of free-moving lithium ions in the negative electrode film layer can be relatively large, which can further shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, improve the insertion and extraction rate of lithium ions, and improve the fast charging performance of the single cell.

[0417] Exemplarily, the first lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-2-hydroxyethyl acrylate copolymer, and the lithium acrylate-acrylonitrile-acrylamide-2-hydroxyethyl acrylate copolymer is derived from a lithium acrylate monomer, an acrylonitrile monomer, an acrylamide monomer, and a 2-hydroxyethyl acrylate monomer. The molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 2-hydroxyethyl acrylate monomer is 30% to 50%: 15% to 45%: 5% to 20%: 20% to 35%. For example, the molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 2-hydroxyethyl acrylate monomer is 35%: 30%: 15%: 20%, or 40%: 20%: 10%: 30%, or 45%: 15%: 20%: 20%, etc.

[0418] The lithium-containing binder of the above material can provide a certain number of lithium ions for the negative electrode film layer, improve the fast charging performance of the single cell, and is not prone to swelling during the charge and discharge process, with a stable structure, so that the cycle performance of the negative electrode film layer is improved during the fast charge and discharge process.

[0419] Optionally, the mass content of the second lithium-containing binder relative to the mass of the second negative electrode film layer is 0.1% to 1%. Exemplarily, the mass content of the second lithium-containing binder relative to the mass of the second negative electrode film layer is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% or the range composed of any two of the above values. The lithium element in the second lithium-containing binder can exist in the form of ions, which can increase the number of free-moving lithium ions in the negative electrode film layer, shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, improve the insertion and extraction rate of lithium ions, and improve the fast charging performance of the single cell.

[0420] The first lithium-containing binder and the second lithium-containing binder can be made of the same material or different materials.

[0421] Optionally, the mass content of lithium element in the second lithium-containing binder is 3% to 10%, and can be optionally 3% to 8%. Exemplarily, the mass content of lithium element in the second lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or the range composed of any two of the above values. When the mass content of lithium element is within the above range, the number of free-moving lithium ions in the negative electrode film layer can be relatively large, which can further shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, improve the intercalation and deintercalation rate of lithium ions, and improve the fast charging performance of the single cell.

[0422] Exemplarily, the second lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-2-hydroxyethyl acrylate copolymer, and the lithium acrylate-acrylonitrile-acrylamide-2-hydroxyethyl acrylate copolymer is derived from a lithium acrylate monomer, an acrylonitrile monomer, an acrylamide monomer, and a 2-hydroxyethyl acrylate monomer. The molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 2-hydroxyethyl acrylate monomer is 30% to 50%: 15% to 45%: 5% to 20%: 20% to 35%. For example, the molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 2-hydroxyethyl acrylate monomer is 35%: 30%: 15%: 20%, or 40%, 20%, 10%, 30%, or 45%, 15%, 20%, 20%, etc.

[0423] The lithium-containing binder of the above material can provide a certain number of lithium ions for the negative electrode film layer, improve the fast charging performance of the single cell, and is not prone to swelling during the charge and discharge process, with a stable structure, so that the cycle performance of the negative electrode film layer is improved during the fast charge and discharge process.

[0424] In some embodiments, the first negative electrode film layer further includes a negative electrode binder, and the second negative electrode film layer further includes a negative electrode binder. The negative electrode binder in the first negative electrode film layer and the negative electrode binder in the second negative electrode film layer independently include at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based acrylic resin (for example, polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0425] In some embodiments, the total content of the first lithium-containing binder and the negative electrode binder in the first negative electrode film layer is greater than the total content of the second lithium-containing binder and the negative electrode binder in the second negative electrode film layer, and the mass content of the first lithium-containing binder relative to the mass of the first negative electrode film layer is less than the mass content of the second lithium-containing binder relative to the mass of the second negative electrode film layer.

[0426] In some embodiments, the negative electrode film layer may optionally further include a negative electrode conductive agent. There is no particular limitation on the type of the negative electrode conductive agent in the embodiments of the present application. As an example, the negative electrode conductive agent may include at least one of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, based on the total weight of the negative electrode film layer, the mass content of the negative electrode conductive agent is ≤5%.

[0427] In some embodiments, the negative electrode film layer may optionally further include a negative electrode binder. In some embodiments, based on the total weight of the negative electrode film layer, the mass content of the negative electrode binder is ≤5%.

[0428] In some embodiments, the negative electrode film layer may optionally further include other additives. As an example, the other additives may include thickeners, dispersants, etc., for example, sodium carboxymethyl cellulose (CMC-Na), PTC thermistor materials, etc. In some embodiments, based on the total weight of the negative electrode film layer, the mass content of the other additives is ≤2%.

[0429] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. As an example of the metal foil, at least one foil of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy may be used. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material in the metal material layer may include at least one of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer may include at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0430] In some embodiments, the ratio CB of the capacity of the negative electrode film layer per unit area to the capacity of the positive electrode film layer per unit area in the single cell is 1.05 to 1.30, and may be optionally 1.07 to 1.15. Exemplarily, the ratio CB of the capacity of the negative electrode film layer per unit area to the capacity of the positive electrode film layer per unit area in the single cell is 1.05, 1.07, 1.1, 1.12, 1.15, 1.18, 1.2, 1.22, 1.25, 1.28, 1.3 or a range composed of any two of the above values.

[0431] When the ratio CB of the capacity of the negative electrode film layer per unit area to the capacity of the positive electrode film layer per unit area in the single cell is within the above range, there are sufficient sites in the negative electrode film layer for lithium insertion, which can reduce the risk of lithium plating and is beneficial to fast charging.

[0432] In the embodiments of the present application, the CB value has the meaning well-known in the art and can be detected by using the equipment and methods well-known in the art. For example, the capacity of the negative electrode film layer per unit area and the capacity of the positive electrode film layer per unit area are calculated respectively, and then the ratio of the two is calculated to obtain the CB value.

[0433] Specifically, taking the upper limit voltage of battery charging as 3.65V and the cut-off voltage of battery discharging as 2.0V as an example for illustration, The capacity of the positive electrode film layer per unit area refers to the actual de-lithiation capacity of the positive electrode active material. The test method is as follows: Disassemble the battery in the PRS340 / 11-119-11 Braun glove box, take the positive electrode plate, assemble it into a CR2430 type half-button battery of positive electrode-lithium sheet, and the area of the positive electrode plate used is amm 2 , and the electrolyte used is 1mol / L LiPF 66 in the solution of EC / EMC / DEC = 3 / 5 / 2 (mass ratio). Then, let the assembled half-button battery stand for 3h, and the test is carried out at 25°C. First, charge (Charge) and de-lithiate in the voltage range of 2.0V to 3.65V at 0.1C, and then discharge (Discharge) and intercalate lithium to 2.0V at 0.05C, and cycle 2 times. Take the discharge cut-off capacity of the second cycle as YmAh. The actual length of the positive electrode plate designed for the battery is bmm, the width is cmm, and the number of sides of the positive electrode active material coated on the positive electrode current collector is d. Then, the capacity of the positive electrode film layer per unit area = Y / (a*b*c*d).

[0434] Specifically, the capacity of the negative electrode film layer per unit area refers to the actual intercalation capacity of the negative electrode active material. The test method is: Disassemble the battery in the PRS340 / 11-119-11 Braun glove box, take the negative electrode plate, assemble it into a CR2430 type half-button battery of negative electrode-lithium sheet, and the area of the negative electrode plate used is fmm 2² , and the electrolyte used is 1mol / L LiPF 66 in the solution of EC / EMC / DEC = 3 / 5 / 2 (mass ratio). Then, let the assembled half-button battery stand for 3h, and the test is carried out at 25°C. First, discharge (Discharge) and intercalate lithium in the voltage range of 2V - 0V at 0.1C, and then charge (Discharge) and de-lithiate to 2V at 0.05C, and cycle 2 times. Take the discharge cut-off capacity of the second cycle as ZmAh. The actual length of the negative electrode plate designed for the battery is hmm, the width is imm, and the number of sides of the negative electrode active material coated on the negative electrode current collector is d. Then, the intercalation capacity of the negative electrode = Z / (f*h*i*d).

[0435] In some embodiments, the single-sided coating weight of the negative electrode film layer is 0.09g / 1540.25mm 2-0.17 g / 1540.25 mm 2 Optionally, the single-sided coating weight of the negative electrode film layer is 110 mg / 1540.25 mm 2 to 150 mg / 1540.25 mm 2 . Exemplarily, the single-sided coating weight of the negative electrode film layer is 90 mg / 1540.25 mm 2 , 92 mg / 1540.25 mm 2 , 95 mg / 1540.25 mm 2 , 96 mg / 1540.25 mm 2 , 100 mg / 1540.25 mm 2 , 102 mg / 1540.25 mm 2 , 104 mg / 1540.25 mm 2 , 105 mg / 1540.25 mm 2 , 108 mg / 1540.25 mm 2 , 110 mg / 1540.25 mm 2 , 112 mg / 1540.25 mm 2 , 114 mg / 1540.25 mm 2 , 115 mg / 1540.25 mm 2 , 116 mg / 1540.25 mm 2 , 118 mg / 1540.25 mm 2 , 120 mg / 1540.25 mm 2 , 122 mg / 1540.25 mm 2 , 125 mg / 1540.25 mm 2 , 128 mg / 1540.25 mm 2 , 130 mg / 1540.25 mm 2 , 132 mg / 1540.25 mm 2 , 135 mg / 1540.25 mm 2 , 137 mg / 1540.25 mm 2 , 140 mg / 1540.25 mm 2 , 142 mg / 1540.25 mm 2 , 145 mg / 1540.25 mm 2 , 148 mg / 1540.25 mm 2 , 150 mg / 1540.25 mm 2 , 152 mg / 1540.25 mm 2 , 155 mg / 1540.25 mm 2, 160 mg / 1540.25 mm 2 , 165 mg / 1540.25 mm 2 , 170 mg / 1540.25 mm 2 Or a range composed of any two of the above values.

[0436] In the embodiments of the present application, the single-sided coating weight of the negative electrode film layer has the meaning well-known in the art and can be detected by using the equipment and methods well-known in the art. The detection method is as described in the single-sided coating weight test method of the film layer above.

[0437] When the single-sided coating weight of the negative electrode film layer is within the above range, the heat generation amount per unit area of the negative electrode plate will not be too large, and the energy density of the battery cell can be improved while taking it into account.

[0438] In some embodiments, the thickness of the negative electrode current collector is 4 μm to 6 μm. Exemplarily, the thickness of the negative electrode current collector is 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm or a range composed of any two of the above values. In other examples, the thickness of the negative electrode current collector is 4 μm to 10 μm, and the thickness of the negative electrode current collector is 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or a range composed of any two of the above values. The negative electrode current collector can be copper.

[0439] When the thickness of the negative electrode current collector is within the above range, the current-carrying capacity of the negative electrode current collector is relatively excellent, and the single-cell battery can have a high energy density.

[0440] In the embodiments of the present application, the thickness of the negative electrode current collector has the meaning well-known in the art and can be detected by using the equipment and methods well-known in the art. For example, the film layer on the surface of the negative electrode current collector is washed away with a solvent, and the thickness of the negative electrode current collector is measured with a micrometer.

[0441] The negative electrode film layer is usually formed by coating a negative electrode slurry on the negative electrode current collector and then drying and cold-pressing. The negative electrode slurry is usually formed by dispersing negative electrode active materials, optional conductive agents, optional binders, and other optional additives in a solvent and stirring evenly. The solvent can be N-methylpyrrolidone (NMP) or deionized water, but is not limited thereto.

[0442] The negative electrode plate does not exclude other additional functional layers besides the negative electrode film layer. For example, in some embodiments, the negative electrode plate of the embodiments of the present application further includes a negative electrode conductive layer sandwiched between the negative electrode current collector and the negative electrode film layer and disposed on the surface of the negative electrode current collector. In some other embodiments, the negative electrode plate of the embodiments of the present application further includes a protective layer covering the surface of the negative electrode film layer.

[0443] In some embodiments, the negative electrode tab further includes a negative electrode conductive layer, which is located between the negative electrode film layer and the negative electrode current collector. The negative electrode conductive layer can further improve the conductivity of the negative electrode tab, reduce the heat generation of the negative electrode tab, and thus reduce the heat generation of the single cell.

[0444] In some embodiments, the thickness of the negative electrode conductive layer is 0.5 μm to 2 μm. Exemplarily, the thickness of the negative electrode conductive layer can be 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.6 μm, 1.8 μm, 2 μm, or a range composed of any two of the above values.

[0445] When the thickness of the negative electrode conductive layer is within the above range, it can further improve the conductivity of the negative electrode tab, reduce the heat generation of the negative electrode tab, and thus reduce the heat generation of the single cell, and can also take into account the improvement of the energy density of the single cell.

[0446] In the embodiments of the present application, the thickness of the negative electrode conductive layer has the meaning well known in the art, and can be detected by devices and methods well known in the art, and the testing method of the negative electrode conductive layer in the foregoing can be adopted.

[0447] In some embodiments, the negative electrode conductive layer includes one or more of a negative electrode conductive agent and a negative electrode binder. The negative electrode conductive agent in the negative electrode conductive layer can improve the conductivity of the negative electrode conductive layer, thereby improving the conductivity of the negative electrode tab and reducing the heat generation of the single cell. The negative electrode binder in the negative electrode conductive layer can improve the bonding performance between the negative electrode current collector and the negative electrode film layer and improve the structural stability of the negative electrode tab.

[0448] In some embodiments, the negative electrode conductive layer may optionally further include other additives. As an example, the other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC), PTC thermistor materials, etc.

[0449] Optionally, the mass content of the negative electrode conductive agent in the negative electrode conductive layer is 20% to 40%. Exemplarily, the mass content of the negative electrode conductive agent is 20%, 25%, 30%, 35%, 40%, or a range composed of any two of the above values.

[0450] Exemplarily, the negative electrode conductive agent includes one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0451] Optionally, the mass content of the negative electrode binder in the negative electrode conductive layer is 60% to 80%. Exemplarily, the mass content of the negative electrode binder is 60%, 65%, 70%, 75%, 80%, or a range composed of any two of the above values.

[0452] Exemplarily, the negative electrode binder includes one or more of styrene-butadiene rubber SBR, water-soluble unsaturated resin SR-1B, water-based acrylic resin, polyvinyl alcohol, sodium alginate, and carboxymethyl chitosan.

[0453] [Positive electrode plate] In some embodiments, the resistance value of the positive electrode plate ranges from 0.1 Ω to 30 Ω, optionally from 0.1 Ω to 5 Ω, and further optionally from 0.1 Ω to 1 Ω. Exemplarily, the resistance of the positive electrode plate is 0.1 Ω, 0.5 Ω, 1 Ω, 1.5 Ω, 2 Ω, 2.5 Ω, 3 Ω, 3.5 Ω, 4 Ω, 4.5 Ω, 5 Ω, 5.5 Ω, 6 Ω, 6.5 Ω, 7 Ω, 7.5 Ω, 8 Ω, 8.5 Ω, 9 Ω, 9.5 Ω, 10 Ω, 10.5 Ω, 11 Ω, 11.5 Ω, 12 Ω, 12.5 Ω, 13 Ω, 13.5 Ω, 14 Ω, 14.5 Ω, 15 Ω, 15.5 Ω, 16 Ω, 16.5 Ω, 17 Ω, 17.5 Ω, 18 Ω, 18.5 Ω, 19 Ω, 20 Ω, 21 Ω, 22 Ω, 23 Ω, 24 Ω, 25 Ω, 26 Ω, 27 Ω, 28 Ω, 29 Ω, 30 Ω or the range composed of any two of the above values.

[0454] In other examples, the resistance of the positive electrode plate can range from 0.01 mΩ to 30 Ω.

[0455] Thereby, the conductivity of the battery subunit can be improved, and further the charging performance of the charging device can be improved.

[0456] In some embodiments, when the single cell is in a 100% charged state, the compaction density of the positive electrode film layer can be but is not limited to 2.5 g / cm 3 -2.8 g / cm 3 , optionally from 2.55 g / cm 3 to 2.70 g / cm 3 . Exemplarily, when the single cell is in a 100% charged state SOC, the compaction density of the positive electrode film layer is 2.2 g / cm 3 , 2.50 g / cm 3 , 2.52 g / cm 3 , 2.55 g / cm 3 , 2.56 g / cm 3 , 2.57 g / cm 3 , 2.58 g / cm 3 , 2.60 g / cm 3 , 2.62 g / cm 3 , 2.65 g / cm 3 , 2.68 g / cm 3 , 2.70 g / cm 3 , 2.72 g / cm 3, 2.75 g / cm 3 , 2.78 g / cm 3 , 2.80 g / cm 3 or a range composed of any two of the above values.

[0457] When the compaction density of the positive electrode film layer is within the above range, it is beneficial to improve the energy density of the single cell. Moreover, since the positive electrode active materials in the positive electrode film layer are stacked more closely and the contact resistance between particles is smaller, the resistance of the electrode sheet can be further reduced, thereby reducing the heat generation during rapid charging. Therefore, by adjusting the compaction density of the positive electrode film layer to a reasonable range, the single cell has both high energy density and high charging rate performance.

[0458] Optionally, the powder compaction density of the positive electrode active material under 30000 N is 2.46 g / cm 3 to 2.8 g / cm 3 . Exemplarily, the powder compaction density of the positive electrode active material under 30000 N is 2.46 g / cm 3 , 2.47 g / cm 3 , 2.48 g / cm 3 , 2.49 g / cm 3 , 2.5 g / cm 3 , 2.51 g / cm 3 , 2.55 g / cm 3 , 2.58 g / cm 3 , 2.60 g / cm 3 , 2.65 g / cm 3 , 2.68 g / cm 3 , 2.70 g / cm 3 , 2.72 g / cm 3 , 2.75 g / cm 3 , 2.78 g / cm 3 , 2.80 g / cm 3 or a range composed of any two of the above values.

[0459] When the powder compaction density of the positive electrode active material under 30000 N is within the above range, the energy density of the single cell can be improved. Moreover, since the positive electrode active materials in the positive electrode film layer can be stacked more closely and the contact resistance between particles is smaller, the resistance of the electrode sheet can be further reduced, thereby reducing the heat generation.

[0460] In the embodiments of the present application, the powder compaction density of the material has the meaning well-known in the art, and can be detected by methods and equipment well-known in the art. Detection is carried out in accordance with the test standard GB / T24533-2009. For example, a certain amount of cathode active material is taken as a sample and added to a mold with a bottom area of 1.327 cm 2 in a UTM7305 type electronic pressure testing machine, pressurized to 3000 kg (equivalent to 30000 N), held for 30 s, then depressurized, held for 10 s, and then the powder compaction density of the cathode active material under the action of 30000 N is recorded and calculated.

[0461] In some embodiments, the single-sided coating weight of the cathode film layer is from 0.2 g / 1540.25 mm 2 to 0.37 g / 1540.25 mm 2 , and can be optionally from 240 mg / 1540.25 mm 2 to 330 mg / 1540.25 mm 2 . Exemplarily, the single-sided coating weight of the cathode film layer is 200 mg / 1540.25 mm 2 , 210 mg / 1540.25 mm 2 , 220 mg / 1540.25 mm 2 , 230 mg / 1540.25 mm 2 , 240 mg / 1540.25 mm 2 , 250 mg / 1540.25 mm 2 , 260 mg / 1540.25 mm 2 , 270 mg / 1540.25 mm 2 , 280 mg / 1540.25 mm 2 , 290 mg / 1540.25 mm 2 , 300 mg / 1540.25 mm 2 , 310 mg / 1540.25 mm 2 , 320 mg / 1540.25 mm 2 , 330 mg / 1540.25 mm 2 , 340 mg / 1540.25 mm 2 , 350 mg / 1540.25 mm 2 , 360 mg / 1540.25 mm 2 , 370 mg / 1540.25 mm 2 or the range composed of any two of the above values.

[0462] When the single-sided coating weight of the positive electrode film layer is within the above range, the heat generation amount per unit area of the positive electrode plate will not be too large, and it can take into account improving the energy density and charging rate performance of the single-cell battery.

[0463] In the embodiments of the present application, the compaction density of the positive electrode film layer of the single-cell battery in the 100% state of charge (SOC) can be detected by the following method. Disassemble the positive electrode plate from the single-cell battery in the 100% state of charge (SOC), and measure the compaction density of the positive electrode film layer. For example, take a single-sided coated positive electrode plate (if it is a double-sided coated electrode plate, one side of the positive electrode film layer can be wiped off first), punch it into small round pieces with an area of S1, weigh it, record it as M1, and measure its thickness H1. Then wipe off the positive electrode film layer of the above-mentioned weighed positive electrode plate, weigh the positive electrode current collector, record it as M0, and measure its thickness H0. The single-sided coating weight of the positive electrode film layer = (the weight M1 of the positive electrode plate - the weight M0 of the positive electrode current collector) / S1, the thickness of the positive electrode film layer = the thickness H1 of the positive electrode plate - the thickness H0 of the positive electrode current collector, and the compaction density of the positive electrode film layer = the single-sided coating weight of the positive electrode film layer / the thickness of the positive electrode film layer.

[0464] In some embodiments, the thickness of the positive electrode current collector is 10 μm - 15 μm, and can be selected from 12 μm to 15 μm. Exemplarily, the thickness of the positive electrode current collector is 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm or the range composed of any two of the above values.

[0465] The positive electrode current collector can be aluminum.

[0466] When the thickness of the positive electrode current collector is within the above range, the current-carrying capacity of the positive electrode current collector is relatively excellent, and it can make the single-cell battery have a high energy density.

[0467] In the embodiments of the present application, the thicknesses of the positive electrode film layer and the positive electrode current collector have the meanings well-known in the art, and can be detected by the equipment and methods well-known in the art. For example, use a micrometer to measure the thickness of the positive electrode plate, remove the film layer on the surface of the positive electrode current collector, and use a micrometer to measure the thickness of the positive electrode current collector. When the positive electrode film layer is single-sided coated, the thickness of the positive electrode film layer is the thickness of the positive electrode plate minus the thickness of the positive electrode current collector. When the positive electrode film layer is double-sided coated, the thickness of the positive electrode film layer is (the thickness of the positive electrode plate minus the thickness of the positive electrode current collector) / 2.

[0468] The positive electrode film layer is usually formed by coating the positive electrode slurry on the positive electrode current collector, followed by drying and cold pressing. The positive electrode slurry is usually formed by dispersing the positive electrode active material, optional conductive agent, optional binder, and any other components in a solvent and stirring evenly. The solvent can be N-methylpyrrolidone (NMP), but is not limited thereto.

[0469] The positive electrode tab does not exclude other additional functional layers besides the positive electrode film layer. For example, in some embodiments, the positive electrode tab of the embodiment of the present application further includes a positive electrode conductive layer sandwiched between the positive electrode current collector and the positive electrode film layer and disposed on the surface of the positive electrode current collector. In some other embodiments, the positive electrode tab of the embodiment of the present application further includes a protective layer covering the surface of the positive electrode film layer.

[0470] In some embodiments, the ratio of the thickness of the positive electrode current collector to the thickness of a single-sided positive electrode film layer is from 0.05 to 0.3. Exemplarily, the ratio of the thickness of the positive electrode current collector to the thickness of a single-sided positive electrode film layer is 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3 or a range composed of any two of the above values.

[0471] When the ratio of the thickness of the positive electrode current collector to the thickness of a single-sided positive electrode film layer is within the above range, the fast charging ability and energy density of the single cell can be improved.

[0472] In some embodiments, the powder resistivity of the positive electrode active material is from 1 Ω·cm to 27.5 Ω·cm, optionally less than or equal to 20 Ω·cm, and optionally less than or equal to 11 Ω·cm. Exemplarily, the powder resistivity of the positive electrode active material can be 27.5 Ω·cm, 20 Ω·cm, 19 Ω·cm, 18 Ω·cm, 17 Ω·cm, 16 Ω·cm, 15 Ω·cm, 14 Ω·cm, 13 Ω·cm, 12 Ω·cm, 11 Ω·cm, 10 Ω·cm, 9 Ω·cm, 8 Ω·cm, 7 Ω·cm, 6 Ω·cm, 5 Ω·cm, 4 Ω·cm, 3 Ω·cm, 2 Ω·cm, 1 Ω·cm or a range composed of any two of the above values.

[0473] The relatively low powder resistivity of the positive electrode active material results in a relatively low resistance of the positive electrode tab and less heat generation of the single cell.

[0474] In the embodiment of the present application, the powder resistivity of the material has the meaning well-known in the art and can be detected by methods and equipment well-known in the art. For example, according to the test standard GB / T30835-2014, a PRCD1100 powder resistivity meter is used for testing.

[0475] In some embodiments, the charging specific capacity of the positive electrode active material at a rate of 0.1C is 150 mAh / g to 170 mAh / g, and may be optionally 157 mAh / g to 170 mAh / g. Exemplarily, the charging specific capacity of the positive electrode active material at a rate of 0.1C is 150 mAh / g, 151 mAh / g, 152 mAh / g, 153 mAh / g, 154 mAh / g, 155 mAh / g, 156 mAh / g, 157 mAh / g, 158 mAh / g, 159 mAh / g, 160 mAh / g, 161 mAh / g, 162 mAh / g, 163 mAh / g, 164 mAh / g, 165 mAh / g, 166 mAh / g, 167 mAh / g, 168 mAh / g, 169 mAh / g, 170 mAh / g or a range composed of any two of the above values.

[0476] When the charging specific capacity of the positive electrode active material at a rate of 0.1C is within the above range, the energy density of the single cell is relatively high.

[0477] In the embodiments of the present application, the specific capacity of the active material has the meaning well-known in the art, and can be tested by the equipment and methods well-known in the art. The test method for the first Coulomb efficiency and the first discharge specific capacity in Appendix G of the national standard GB / T 24533-2019 can be adopted. Using metallic lithium as the negative electrode and the sample electrode sheet containing the above materials as the positive electrode, a half-button cell is assembled. Under the condition of 23°C ± 2°C, the half-button cell is placed on a battery tester or other test equipment with the same performance, and the discharge capacity is obtained through charge and discharge at a rate of 0.1C, and then the capacity is divided by the mass of the active material of the electrode sheet to obtain the charging specific capacity parameter.

[0478] In some embodiments, the positive electrode active material includes lithium-containing phosphate, and the lithium-containing phosphate includes phosphate particles and a coating layer. The coating layer coats the surface of the phosphate particles, and the coating layer contains one or more elements of C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0479] By having a coating layer on the surface of the phosphate particles, the conductivity of the lithium-containing phosphate with an olivine structure can be improved, the powder resistivity of the material can be reduced, and it is beneficial to improve the migration rate of lithium ions, improve the fast charging ability of the battery, and reduce the heat generation of the single cell.

[0480] The mass ratio of the lithium-containing phosphate with olivine structure in the positive electrode active material can be greater than or equal to 80% and less than or equal to 100%. It can be considered that the positive electrode active material of this application is a lithium-containing phosphate system with olivine structure. When the mass ratio of the lithium-containing phosphate with olivine structure is less than 100%, the positive electrode active material can also include common positive electrode active materials, such as at least one of lithium-containing transition metal oxides, including but not limited to. Examples of lithium-containing transition metal oxides can include but are not limited to at least one of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their respective modified compounds.

[0481] Optionally, the mass ratio of the lithium-containing phosphate with olivine structure in the positive electrode active material is 100%.

[0482] In some embodiments, the phosphate particles include a compound with the general formula Li x1 A y1 Me a M b P 1-c X c Y z where 0.5 ≤ x1 ≤ 1.3, 0 ≤ y1 ≤ 1.3, and 0.9 ≤ x1 + y1 ≤ 1.3, 0.9 ≤ a ≤ 1.5, 0 ≤ b ≤ 0.5, and 0.9 ≤ a + b ≤ 1.5, 0 ≤ c ≤ 0.5, 3 ≤ z ≤ 5, A includes one or more of Na, K, Mg, Me includes one or more of Mn, Fe, Co, Ni, M includes one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, Ce, X includes one or more of S, Si, Cl, B, C, N, and Y includes one or more of O, F. The phosphate particles have relatively excellent cycle stability, which is beneficial to improving the cycle performance of the single cell.

[0483] Exemplarily, the chemical elements in the phosphate particles at least include Li, Fe, P, Al, Ti, and the mass ratios of the respective elements are (3 - 4):(30 - 35):(15 - 20):(0.01 - 0.1):(0.1 - 0.5) in sequence.

[0484] Exemplarily, the phosphate particles include one or more of LiFePO4, LiMnPO4, LiNiPO4, and LiCoPO4. The charge and discharge process of the single cell is accompanied by the deintercalation and consumption of active ions such as Li, and the molar content of Li in the single cell is different when it is discharged to different states. In the enumeration of positive electrode active materials LiFePO4, LiMnPO4, LiNiPO4, LiCoPO4, etc., the molar content of Li is the initial state of the material, that is, the state before feeding. The positive electrode active material is used in the battery system, and after the charge and discharge cycle, the molar content of Li may change. In the enumeration of positive electrode active materials LiFePO4, LiMnPO4, LiNiPO4, LiCoPO4, etc. in the embodiment of the present application, the molar content of oxygen O is only a theoretical state value. The release of lattice oxygen will cause the molar content of oxygen O to change. In fact, the molar content of oxygen O will fluctuate. The above situations are all within the scope of protection of the present application.

[0485] In some embodiments, the coating layer includes a general formula of Li 3-d Fe 2-d M 2d (PO x2 ) y2 The fast ion conductor M2 includes one or more elements of Ti, Zr, Hf, Ge and Sn, 0≤d≤1, 0<x2<5, 0<y2<4.

[0486] Exemplarily, the fast ion conductor is a material having a NASICON structure, for example, including one or more of lithium iron titanium phosphate Li2FeTi(PO4)3, lithium iron zirconium phosphate Li2FeZr(PO4)3, and lithium iron tin phosphate Li2FeSn(PO4)3.

[0487] Fast ion conductors with NASICON structures are materials with ultrafast ion conduction capabilities, rich three-dimensional lithium ion diffusion and transmission channels, and have the advantages of high ion conduction efficiency and strong structural stability in multiple lithium de- and lithium insertion processes. Coating fast ion conductors with NASICON structures on the surface of phosphate particles can significantly increase the transmission rate of lithium ions in multiple lithium de- / lithium insertion at the positive terminal, improve the ionic conductivity of the positive electrode active material, and improve the rapid charging capability of the single cell. In addition, it can also increase the gram capacity and the energy density of the corresponding single cell.

[0488] In some embodiments, the coating layer further includes carbon.

[0489] The carbon-based material and the fast ion conductor can be arranged in layers. For example, the carbon-based material serves as an independent carbon coating layer, and the fast ion conductor serves as an independent fast ion conductor layer. The carbon coating layer can coat the surface of the phosphate particles, and the fast ion conductor layer is located on the surface of the carbon coating layer, that is, the fast ion conductor layer is located on the side of the carbon coating layer away from the phosphate particles. Alternatively, the fast ion conductor layer can coat the surface of the phosphate particles, and the carbon coating layer is located on the surface of the fast ion conductor layer, that is, the carbon coating layer is located on the side of the fast ion conductor layer away from the phosphate particles. Of course, the carbon-based material and the fast ion conductor can also be arranged in the same layer.

[0490] Optionally, the carbon coating layer can be formed by carbonizing an organic carbon source (such as glucose, polyethylene glycol, etc.) on the surface of the fast ion conductor layer. The carbon coating layer can partially coat the fast ion conductor layer or completely coat the fast ion conductor layer. The setting of the carbon coating layer can significantly improve the electronic conductivity of the phosphate particles, make up for the defect of poor electronic conduction performance of the phosphate particles, and improve the energy density of the single-cell battery. Specifically, the setting of the carbon coating layer endows the positive electrode active material of the present application with the following advantages: The carbon coating layer in the positive electrode active material of the present application provides a suitable channel for the transmission of electrons, can significantly improve the conduction rate of electrons during multiple de-lithiation and lithiation processes, improve the electronic conductivity of the lithium-containing phosphate, improve the charging capacity of the corresponding single-cell battery, and also improve the energy density.

[0491] The carbon coating layer of the positive electrode active material of the present application has a loose and porous structure, which enables the electrolyte to come into full and effective contact with the lithium-containing phosphate, thereby improving the transmission rate of lithium ions at the phase interface and improving the charging capacity of the single-cell battery.

[0492] Coating a layer of carbon coating layer on the surface of the lithium-containing phosphate can not only improve the conductivity of the lithium-containing phosphate, but also improve the structural stability of the positive electrode active material, effectively alleviate the iron dissolution phenomenon of the positive electrode active material during the long-term storage and cyclic use of the single-cell battery, thereby improving the cycle life of the single-cell battery. The positive electrode active material of the present application is based on lithium-containing phosphate, giving full play to the advantages of low cost, high use reliability, and good cycle stability of lithium-containing phosphate. At the same time, the coating layers (fast ion conductor layer and carbon coating layer) are used to solve the disadvantages of poor electronic conductivity and ion conductivity. The single-cell battery prepared from the positive electrode active material of the present application can improve the energy density of the single-cell battery on the premise of excellent cycle performance.

[0493] In the embodiments of the present application, the content of elements in the positive electrode active material has the meaning well-known in the art, and can be detected by equipment and methods well-known in the art. For example, referring to EPA 6010D-2014, it is tested by inductively coupled plasma atomic emission spectrometry, and determined by inductively coupled plasma optical emission spectrometry (ICP-OES, instrument model: Thermo ICAP7400). After discharging the single-cell battery to 0% state of charge (SOC) and disassembling the positive electrode sheet, it is cleaned with DMC and dried, and then after removing impurities by high-temperature calcination, 0.4 g of the positive electrode active material is weighed, and 10 ml (50% concentration) of aqua regia is added thereto. Then it is placed on a flat plate at 180 °C for 30 min. After digestion on the flat plate, it is fixed to a volume of 100 mL, and quantitative testing is carried out by the standard curve method.

[0494] In some embodiments, the graphitization degree of the positive electrode active material is from 0.15 to 0.32, and can be optionally from 0.19 to 0.26. Exemplarily, the graphitization degree of the positive electrode active material is 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32 or a range composed of any two of the above values.

[0495] When the graphitization degree of the positive electrode active material is within the above range, it is beneficial to improve the conductivity of the positive electrode active material, reduce the heat generation of the positive electrode sheet, and thus reduce the heat generation of the single-cell battery.

[0496] In the embodiments of the present application, the higher the graphitization degree of the material, the lower the degree of disorder, and it can be tested according to the test standard JIS / K 0131-1996 "General Rules for X-ray Diffraction Analysis Method".

[0497] In some embodiments, the mass content of carbon element in the lithium-containing phosphate with olivine structure is from 1% to 2%, and the specific surface area of the lithium-containing phosphate with olivine structure is 5m 2 / g to 18m 2 / g.

[0498] Optionally, the mass content of carbon element in the lithium-containing phosphate with olivine structure is from 1% to 2%, and the specific surface area of the lithium-containing phosphate with olivine structure is 7.5m 2 / g to 14m 2 / g.

[0499] Exemplarily, the mass content of carbon element in the lithium-containing phosphate with olivine structure is 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2% or a range composed of any two of the above values.

[0500] Exemplarily, the specific surface area of the lithium-containing phosphate with an olivine structure is 5 m 2 / g, 6 m 2 / g, 7 m 2 / g, 8 m 2 / g, 9 m 2 / g, 10 m 2 / g, 11 m 2 / g, 12 m 2 / g, 13 m 2 / g, 14 m 2 / g, 15 m 2 / g, 16 m 2 / g, 17 m 2 / g, 18 m 2 / g or a range composed of any two of the above values.

[0501] Carbon element mainly exists in the material in the form of a carbon coating layer. The carbon coating layer is loose and porous, which is beneficial to increasing the specific surface area of the material, more beneficial to the effective contact between the electrolyte and the phosphate particles, and beneficial to the transmission of lithium ions at the phase interface. In addition, when the mass content of the carbon element is within the above range, the conductivity of the lithium-containing phosphate with an olivine structure can be significantly improved, which is beneficial to enhancing the ionic conductivity and electronic conductivity of the lithium-containing phosphate with an olivine structure, and can improve the rapid charging ability and energy density of the single cell.

[0502] In the embodiments of the present application, the specific surface area of the material has the meaning well known in the art, and can be detected by using the equipment and methods well known in the art. For example, it can be detected according to the test standard GB / T 19587-2017. Taking the positive electrode active material as a sample, the specific surface area is tested by a Tri-Star 3020 specific surface area and pore size analyzer of Micromeritics Company in the United States.

[0503] In some embodiments, the volume distribution particle size of the positive electrode active material satisfies: 1 µm ≤ Dv50 ≤ 2 µm, 0.4 µm ≤ Dv10 ≤ 0.7 µm.

[0504] Exemplarily, Dv50 of the positive electrode active material can be 1 µm, 1.1 µm, 1.15 µm, 1.2 µm, 1.25 µm, 1.3 µm, 1.35 µm, 1.4 µm, 1.45 µm, 1.5 µm, 1.55 µm, 1.6 µm, 1.65 µm, 1.7 µm, 1.75 µm, 1.8 µm, 1.85 µm, 1.9 µm, 1.95 µm, 2 µm or a range composed of any two of the above values.

[0505] Exemplarily, the Dv10 of the positive electrode active material may be 0.4 µm, 0.45 µm, 0.5 µm, 0.55 µm, 0.6 µm, 0.65 µm, 0.7 µm, or a range composed of any two of the above values.

[0506] The particle size of the positive electrode active material is relatively small, the lithium deintercalation / insertion path of lithium ions in the positive electrode active material is short, and the heat generation is less. Moreover, the particle size of the above positive electrode active material is not too small, and basically no agglomeration occurs during the processing and preparation process, so that the performance of the positive electrode active material is stable.

[0507] In the embodiments of the present application, the volume average particle size Dv50 of the material refers to the particle size corresponding to 50% in the volume distribution, and the volume average particle size Dv10 of the material refers to the particle size corresponding to 10% in the volume distribution. It can be detected by using equipment and methods well-known in the art. For example, taking the positive electrode active material as a sample, according to the test standard GB / T 19077-2016, the Dv50 and Dv10 of the particles are tested by a Mastersizer 2000E laser particle size analyzer, etc.

[0508] When the positive electrode active material includes other materials in addition to the lithium-containing phosphate with an olivine structure, the volume distribution particle size of the positive electrode active material refers to the volume distribution particle size of all positive electrode active materials.

[0509] In some embodiments, the lithium-containing phosphate with an olivine structure is granular. The lithium-containing phosphate with an olivine structure includes secondary particles, and the secondary particles include a plurality of primary particles. The average particle size of the primary particles is 200 nm to 500 nm. Exemplarily, the average particle size of the primary particles is 200 nm, 220 nm, 250 nm, 280 nm, 300 nm, 320 nm, 350 nm, 380 nm, 400 nm, 420 nm, 450 nm, 480 nm, 500 nm, or a range composed of any two of the above values.

[0510] The average particle size of the primary particles is relatively small, the lithium deintercalation / insertion path of lithium ions in the positive electrode active material is short, and the heat generation is less.

[0511] In the embodiments of the present application, the secondary particles refer to aggregated particles formed by the aggregation of two or more primary particles. The primary particles and the secondary particles can be easily distinguished by experimental means (such as taking SEM images using a scanning electron microscope), and the average particle size of the primary particles can be obtained by testing in the SEM image of the scanning electron microscope. The SEM test parameters can be set as follows: the working voltage (EHT) is 10.00 kV, the InLens detector is used, the working distance is 4.6 mm, and the magnification is 1000X.

[0512] In some embodiments, the positive electrode film layer further includes one or more of ternary materials, lithium phosphate, lithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium molybdate, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium manganate, lithium tartrate, trilithium citrate, lithium nickelate, and lithium ferrate. The above materials can be used as lithium supplement agents, which can supplement lithium ions to the positive electrode film layer, make up for the irreversible loss of lithium ions in the system, and improve the capacity, thereby improving the energy density of the single-cell battery.

[0513] Optionally, the ternary material includes Li x3 A y3 Ni a3 Co b3 Mn c M3 (1-a3-b3-c3) Y3 z3 , where 0 < x3 ≤ 2.1, 0 < y3 ≤ 2.1, and 0.9 ≤ x3 + y3 ≤ 2.1, 0 ≤ a3 ≤ 1, 0 ≤ b3 ≤ 1, 0 ≤ c3 ≤ 1, and 0.1 ≤ a3 + b3 + c3 ≤ 1, 1.8 ≤ z3 ≤ 3.5, A includes one or several of Na, K, and Mg, M3 includes one or several of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, Ce, and Y3 includes one or several of O and F.

[0514] Exemplarily, the ternary materials include at least one of LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (NCM523), LiNi 0.6 Co 0.2 Mn 0.2 O2 (NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (NCM811), LiNi 0.80 Co 0.15 Al 0.05 O2.

[0515] In some embodiments, the mass content of the lithium supplement agent in the positive electrode film layer is 0.5% to 5%, such as 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a range composed of any two of the above values. When the mass content of the lithium supplement agent is within the above range, it can supplement lithium ions to the positive electrode film layer, make up for the irreversible lithium ion loss in the system, and improve the capacity, thereby improving the energy density of the single cell.

[0516] The lithium supplement agent can be in the same layer as the positive electrode active material or in different layers. When the lithium supplement agent and the positive electrode active material are in different layers, the lithium supplement agent can be in the lithium supplement layer, and the positive electrode active material can be in the positive electrode active material layer. In other words, the positive electrode film layer includes a lithium supplement layer and a positive electrode active material layer. The positive electrode active material layer can be disposed on at least one side of the positive electrode current collector, and the lithium supplement layer can be located between the positive electrode active material layer and the positive electrode current collector. Alternatively, the lithium supplement layer can be disposed on at least one side of the positive electrode current collector, and the positive electrode active material layer can be located between the lithium supplement layer and the positive electrode current collector. Optionally, the lithium supplement layer can be located between the positive electrode active material layer and the positive electrode current collector. During the charge and discharge cycle of the single cell, the lithium supplement agent in the lithium supplement layer can be gradually released into the system to make up for the lithium loss in the battery system.

[0517] In some embodiments, the positive electrode film layer may further optionally include a positive electrode conductive agent. The embodiments of the present application do not particularly limit the type of the positive electrode conductive agent. As an example, the positive electrode conductive agent includes at least one of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0518] In some embodiments, based on the mass of the positive electrode film layer, the mass content of the positive electrode conductive agent is ≤5%.

[0519] In some embodiments, the positive electrode film layer may further optionally include a positive electrode binder. The embodiments of the present application do not particularly limit the type of the positive electrode binder. As an example, the positive electrode binder may include at least one of polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polyacrylic acid, and fluorinated acrylate resins. In some embodiments, based on the mass of the positive electrode film layer, the mass content of the positive electrode binder is ≤5%.

[0520] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. As an example of the metal foil, at least one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy foils may be used. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material of the metal material layer may include at least one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer may include at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0521] In some embodiments, the positive electrode sheet further includes a positive electrode conductive layer, which is located between the positive electrode film layer and the positive electrode current collector. The positive electrode conductive layer can further improve the conductivity of the positive electrode sheet and reduce the heat generation of the positive electrode sheet, thereby reducing the heat generation of the single cell.

[0522] In some embodiments, the thickness of the positive electrode conductive layer is 0.5 μm to 2 μm. Exemplarily, the thickness of the positive electrode conductive layer may be 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.6 μm, 1.8 μm, 2 μm, or a range composed of any two of the above values.

[0523] When the thickness of the positive electrode conductive layer is within the above range, it can further improve the conductivity of the positive electrode sheet, reduce the heat generation of the positive electrode sheet, thereby reducing the heat generation of the single cell, and can also take into account the improvement of the energy density of the single cell.

[0524] In the embodiments of the present application, the thickness of the positive electrode conductive layer has the meaning well known in the art, and can be detected by using the equipment and methods well known in the art. For example, tomographic scanning of the positive electrode sheet can be performed to directly measure the thickness of the positive electrode conductive layer.

[0525] In some embodiments, the positive electrode conductive layer includes one or more of a positive electrode conductive agent and a positive electrode binder.

[0526] Optionally, the mass content of the positive electrode conductive agent in the positive electrode conductive layer is 30% to 50%. Exemplarily, the mass content of the positive electrode conductive agent is 30%, 35%, 40%, 45%, 50%, or a range composed of any two of the above values.

[0527] Exemplarily, the positive electrode conductive agent includes one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. The positive electrode conductive agent in the positive electrode conductive layer can improve the conductivity of the positive electrode conductive layer, thereby improving the conductivity of the positive electrode sheet and reducing the heat generation of the single cell.

[0528] Optionally, the mass content of the positive electrode binder in the positive electrode conductive layer is 50% to 70%. Exemplarily, the mass content of the positive electrode binder is 50%, 60%, 65%, 70%, or a range consisting of any two of the above values.

[0529] Exemplarily, the positive electrode binder includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polyacrylic acid and fluorine-containing acrylic resin. The positive electrode binder in the positive electrode conductive layer can improve the bonding performance between the positive electrode current collector and the positive electrode film layer, and improve the structural stability of the positive electrode sheet.

[0530] [Isolation film] In some embodiments, the isolation film includes a base film having a porous structure, and the porosity of the base film is 20% to 70%, and optionally 35% to 60%. Exemplarily, the porosity of the base film is 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or a range consisting of any two of the above values.

[0531] When the porosity of the base film in the embodiment of the present application is within the above range, the migration ability of lithium ions in the isolation film can be improved, and the internal resistance of the single battery cell can be further reduced, thereby reducing heat generation.

[0532] In the embodiments of the present application, porosity refers to the percentage of the pore volume in the separator to the total volume of the separator. The porosity can be tested in accordance with the standard GB / T36363-2018 "Polyolefin separator for single cell". It should be noted that the actual test process can be slightly different from the standard test process according to the difference in test instruments, test errors, and in order to eliminate the test influence on porosity as much as possible, so as to obtain a more accurate test value.

[0533] In some embodiments, the thickness of the base film may be, but is not limited to, 6 μm to 12 μm, and may be 6 μm to 9 μm. For example, the thickness of the base film is 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 20.5 μm, or a range consisting of any two of the above values.

[0534] Optionally, the base film may be made of polypropylene.

[0535] When the thickness of the base film is within the above range, the migration path of lithium ions in the base film is shorter, which can further reduce the internal resistance of the single cell and thus reduce heat generation.

[0536] In the embodiments of the present application, the separator may be a base film. Optionally, the separator further includes a functional layer disposed on at least one side of the base film. The functional layer may include inorganic particles to improve the heat resistance of the separator. Optionally, the functional layers are disposed on both sides of the base film.

[0537] In some embodiments, the functional layer includes a first functional layer and a second functional layer. The first functional layer is located on one side of the base film and includes first inorganic particles. The second functional layer is located on the other side of the base film and includes composite particles. The composite particles include second inorganic particles and a plurality of non-fluoropolymer particles. The second inorganic particles are attached to the surface of and / or dispersed in the non-fluoropolymer particles.

[0538] The first functional layer and the second functional layer have good heat resistance, which can improve the heat resistance of the separator.

[0539] Optionally, the first functional layer may include a binder, optionally including at least one of a fluorine-containing binder or a polyacrylic acid binder, such as polyvinylidene fluoride.

[0540] Optionally, the first inorganic particles include one or more of silicon oxide, aluminum oxide, boehmite, barium sulfate, calcium oxide, titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, and tin oxide. The above first inorganic particles can improve the heat resistance of the first functional layer.

[0541] In the embodiments of the present application, the meaning of the thickness of the base film is well-known in the art and can be detected by methods and equipment well-known in the art. For example, a newly prepared separator can be taken as a sample, or a single cell that has been fully discharged (discharged to the lower cut-off voltage so that the charged state of the battery is about 0% SOC) can be disassembled in reverse, the separator is obtained from the single cell, and the separator is dried and used as a sample. The separator is cut off with an ion beam cutter to form a cross-section. Subsequently, a scanning electron microscope is used to measure the thickness of the cross-section of the separator and its respective layers.

[0542] The non-fluoropolymer particles in the second functional layer refer to polymers that are non-fluorinated polymers. For example, the non-fluoropolymer particles include acrylate copolymers. Optionally, the acrylate copolymers include acrylate-acrylonitrile-acrylamide-acrylate copolymers. The acrylate copolymers have excellent adhesion properties and relatively high adhesion stability to the base film. The molar ratio of each monomer in the copolymer can be any ratio, such as 35%:30%:15%:20%, or 40%:20%:10%:30%, or 45%:15%:20%:20%, etc.

[0543] The second inorganic particles in the composite particles prevent the non-fluoropolymer particles from easily adhering to each other during the high-temperature treatment in the granulation process, creating pores in the composite particles, which is beneficial to the transmission of lithium ions, improving the ionic conductivity of the separator membrane. Moreover, the second inorganic particles can also increase the compression modulus of the composite particles. During charge and discharge, the composite particles are not easily deformed, making the structure of the separator membrane more stable, enhancing the kinetic performance of the single-cell battery and improving the fast-charging performance. Optionally, compared with the first functional layer, the second functional layer is disposed closer to the negative electrode tab. Since the composite particles are not easily deformed, the separator membrane basically does not cause side effects such as extrusion to the negative electrode tab, ensuring the stable kinetic performance of the negative electrode tab. Correspondingly, the first functional layer is disposed closer to the positive electrode tab.

[0544] Optionally, the second inorganic particles include one or more of silicon oxide, aluminum oxide, boehmite, barium sulfate, calcium oxide, titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, and tin oxide. Optionally, the second inorganic particles include silicon oxide. The above-mentioned second inorganic particles can improve the heat resistance of the second functional layer and can form composite particles in combination with the non-fluoropolymer, further improving the cycle stability and kinetic performance of the separator membrane, and enhancing the cycle performance and fast-charging performance of the single-cell battery.

[0545] The average particle size of the second inorganic particles is from 5 nm to 100 nm, optionally from 10 nm to 100 nm, and optionally from 5 nm to 20 nm. Exemplarily, the average particle size of the second inorganic particles is 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm or a range composed of any two of the above values. When the average particle size of the second inorganic particles is within the above range, it is beneficial to improve the heat resistance and compression modulus of the composite particles.

[0546] In the embodiments of the present application, the average particle size of the second inorganic particles has the meaning well-known in the art and can be detected using equipment and methods well-known in the art. For example, after obtaining the separator membrane and drying it as a sample, the separator membrane is cut with an ion beam cutter to form a cross-section. Subsequently, a scanning electron microscope is used to measure the particle size of the second inorganic particles in the separator membrane, and the particle sizes of multiple, for example, 50, second inorganic particles are measured, and their average value is calculated as the average particle size of the second inorganic particles.

[0547] In some embodiments, the ionic conductivity of the separator membrane is from 0.3 mS / cm to 0.6 mS / cm. Exemplarily, the ionic conductivity of the separator membrane is 0.3 mS / cm, 0.35 mS / cm, 0.4 mS / cm, 0.45 mS / cm, 0.5 mS / cm, 0.55 mS / cm, 0.6 mS / cm or a range composed of any two of the above values.

[0548] When the ionic conductivity of the separator membrane is within the above range, the ability of the separator membrane to migrate lithium ions can be further improved, and the fast charging performance of the single cell can be improved.

[0549] In the embodiments of the present application, the ionic conductivity of the separator membrane has the meaning well-known in the art and can be detected by using the equipment and methods well-known in the art. For example, Prepare a 2025-type button battery for testing: In a vacuum glove box, place a lithium sheet in the negative electrode case of the battery, add 150 μL of electrolyte thereto, and the electrolyte is a solution of 1 mol / L LiPF6 in EC / EMC / DEC = 3 / 5 / 2 (mass ratio), and then place the separator membrane (with an area of 3.14 cm 2 , a thickness of 12 μm) so that it is in close contact with the lithium sheet, then add 25 μL of electrolyte, and finally place the positive electrode sheet (the positive electrode sheet can be the positive electrode sheet in Example 1) thereon and seal it. Take out the assembled button battery from the vacuum glove box and place it for 24 h for the next test.

[0550] Test: On an electrochemical workstation, perform tests in the frequency range of 10 -1 ~10 6 Hz to obtain the separator membrane resistance Rb, and calculate the ionic conductivity σ (unit: mS / cm) through the following formula, σ = L / (R b ×S) where: R b is the separator membrane resistance, and L and S are the thickness and area of the separator membrane to be measured, respectively.

[0551] In some embodiments, the base film includes at least one of glass fiber, non-woven fabric, and polyolefin. The base film can be a single-layer film or a multi-layer composite film, and there is no particular limitation. When the base film is a multi-layer composite film, the materials of each layer can be the same or different, and there is no particular limitation.

[0552] Optionally, the polyolefin includes at least one of polyethylene, polypropylene, and polyvinylidene fluoride.

[0553] In some embodiments, the positive electrode sheet, the separator membrane, and the negative electrode sheet can be made into an electrode assembly by a winding process and / or a stacking process.

[0554] Figure 23 and Figure 24 shows a schematic structural diagram of a single cell.

[0555] In some embodiments, the single cell 7 may include a housing 20.

[0556] In some embodiments, the housing 20 of the single cell 7 may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The housing 20 of the single cell 7 may also be a soft package, such as a pouch soft package. The material of the soft package may be plastic, such as at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0557] The housing 20 has a hollow structure, and the housing 20 can be used to encapsulate the above-mentioned electrode assembly 10 and electrolyte.

[0558] The preparation method of the single cell 7 according to the embodiments of the present application is well-known. In some embodiments, the positive electrode sheet, the separator, the negative electrode sheet, and the electrolyte can be assembled to form the single cell 7. As an example, the positive electrode sheet, the separator, and the negative electrode sheet can be formed into the electrode assembly 10 through a winding process and / or a stacking process. The electrode assembly 10 is placed in the housing 20, and after drying, the electrolyte is injected. After processes such as vacuum packaging, standing, forming, and shaping, the single cell 7 is obtained.

[0559] In some embodiments, the housing 20 includes a housing body 21 and an end cap 22. The housing body 21 has an opening, and the end cap 22 covers the opening.

[0560] The shape of the housing body 21 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cylindrical structure, a cylindrical housing can be selected. If the electrode assembly 10 is a cuboid structure, a cuboid housing can be selected. Optionally, both the electrode assembly 10 and the housing body 21 are cuboid structures.

[0561] In some embodiments, the material of the housing body 21 includes steel. Steel has a high mechanical strength and is not easily deformed, which can improve the service reliability and cycle performance of the single cell. Optionally, the mass ratio of steel in the housing body 21 is the highest.

[0562] Optionally, the thickness of the housing body 21 is 0.1 mm to 0.5 mm, and can be selected as 0.2 mm to 0.35 mm. Exemplarily, the thickness of the housing body 21 is 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm or a range composed of any two of the above values. When the thickness of the housing body 21 is within the above range, the housing body 21 has a high mechanical strength, which can improve the service reliability and cycle performance of the single cell 7, and the housing body 21 occupies less space and has more internal space, which is beneficial to improving the energy density of the single cell 7.

[0563] Viewed from the outer shape of the electrode assembly 10, the electrode assembly 10 includes a main body portion 12, a first tab 11 and a second tab 13, and the first tab 11 and the second tab 13 protrude from the main body portion 12. The first tab 11 is the part of the first electrode plate where the active material layer is not coated, and the second tab 13 is the part of the second electrode plate where the active material layer is not coated. The first tab 11 and the second tab 13 are used to lead out the current in the main body portion 12. The polarities of the first electrode plate and the second electrode plate are opposite. In other words, one of the first electrode plate and the second electrode plate is the positive electrode plate, and the other of the first electrode plate and the second electrode plate is the negative electrode plate. Of course, the first tab 11 can be the positive tab, and the second tab 13 can be the negative tab.

[0564] Taking the first tab 11 as the negative tab and the second tab 13 as the positive tab as an example for illustration, the negative current collector portion of the negative electrode plate where the active material layer is not coated is the negative tab. The active material coated on the negative current collector of the negative electrode plate constitutes the negative electrode film layer. The negative electrode film layer and the negative current collector coated with the active material are part of the main body portion 12. The positive current collector portion of the positive electrode plate where the active material layer is not coated is the positive tab. The active material coated on the positive current collector of the positive electrode plate constitutes the positive electrode film layer. The positive electrode film layer and the positive current collector coated with the active material are part of the main body portion 12.

[0565] The first tab 11 and the second tab 13 can extend from the same side of the main body portion 12, or can extend from opposite sides respectively.

[0566] Optionally, the number of the first tabs 11 located on the same side of the main body portion 12 is at least one, and can be optionally at least two. At least two first tabs 11 can increase the current-carrying capacity of the first tab 11.

[0567] Optionally, the number of the second tabs 13 located on the same side of the main body portion 12 is at least one, and can be optionally at least two. At least two second tabs 13 can increase the current-carrying capacity of the second tab 13.

[0568] In some embodiments, the single cell 7 further includes a first electrode terminal 31, and the first electrode terminal 31 is electrically connected to the first tab 11. Optionally, the first electrode terminal 31 and the first tab 11 are welded. The first electrode terminal 31 and the first tab 11 can be connected through an adapter, or can be connected without using an adapter. Optionally, the first electrode terminal 31 and the first tab 11 are connected without using an adapter, that is, the first electrode terminal 31 and the first tab 11 are directly welded, which can reduce the resistance at the connection, and is beneficial to reducing the overall internal resistance of the single cell 7.

[0569] When the first tab 11 is a negative electrode tab, the first electrode terminal 31 is a negative terminal. When the first tab 11 is a positive electrode tab, the first electrode terminal 31 is a positive terminal.

[0570] In some embodiments, the single cell 7 further includes a second electrode terminal 32, and the second electrode terminal 32 is electrically connected to the second tab 13. Optionally, the second electrode terminal 32 and the second tab 13 are welded. The second electrode terminal 32 and the second tab 13 can be connected through an adapter, or can be connected without using an adapter. Optionally, the second electrode terminal 32 and the second tab 13 are connected without using an adapter, that is, the second electrode terminal 32 and the second tab 13 are directly welded, which can reduce the resistance at the connection and is beneficial to reducing the overall internal resistance of the single cell 7.

[0571] When the second tab 13 is a negative electrode tab, the second electrode terminal 32 is a negative terminal. When the second tab 13 is a positive electrode tab, the second electrode terminal 32 is a positive terminal.

[0572] Optionally, the number of the first electrode terminals 31 on the same side of the main body 12 is at least one, and can be at least two. At least two first electrode terminals 31 can increase the current-carrying capacity of the first electrode terminals 31.

[0573] Further optionally, the current-carrying area of the first electrode terminals 31 on one side is 150 mm 2 to 1000 mm 2 , and can be 200 mm 2 to 1000 mm 2 . The current-carrying area of the first electrode terminals 31 refers to the sum of the current-carrying areas of all the first electrode terminals 31 on the same side of the main body 12. The current-carrying area of the first electrode terminals 31 can be understood as the cross-sectional area of the first electrode terminals 31, and this cross-section is perpendicular to the thickness direction of the end cap 22.

[0574] Exemplarily, the current-carrying area of the first electrode terminals 31 on one side can be 150 mm 2 , 200 mm 2 , 210 mm 2 , 250 mm 2 , 280 mm 2 , 300 mm 2 , 320 mm 2 , 350 mm 2 , 380 mm 2 , 400 mm 2 , 450 mm 2 , 500 mm 2 , 550 mm 2 , 600 mm 2 , 650 mm 2, 700mm 2 , 750mm 2 , 800mm 2 , 850mm 2 , 900mm 2 , 950mm 2 , 1000mm 2 or a range composed of any two of the above values.

[0575] Optionally, the number of the second electrode terminals 32 on the same side of the main body 12 is at least one, optionally at least two, and at least two second electrode terminals 32 can increase the over-current capacity of the second electrode terminals 32.

[0576] Further optionally, the over-current area of the second electrode terminals 32 on one side is 150mm 2 to 1000mm 2 , optionally 200mm 2 to 1000mm 2 The over-current area of the second electrode terminals 32 on one side refers to the sum of the over-current areas of all the second electrode terminals 32 on the same side of the main body 12. The over-current area of the second electrode terminals 32 can be understood as the cross-sectional area of the second electrode terminals 32, and this cross-section is perpendicular to the thickness direction of the end cover 22.

[0577] Exemplarily, the over-current area of the second electrode terminals 32 on one side can be 150mm 2 , 200mm 2 , 210mm 2 , 250mm 2 , 280mm 2 , 300mm 2 , 320mm 2 , 350mm 2 , 380mm 2 , 400mm 2 , 450mm 2 , 500mm 2 , 550mm 2 , 600mm 2 , 650mm 2 , 700mm 2 , 750mm 2 , 800mm 2 , 850mm 2 , 900mm 2 , 950mm 2 , 1000mm 2 or a range composed of any two of the above values.

[0578] Such as Figure 25As shown, in some embodiments of the present application, the single cell 7 according to the implementation manner of the present application can be assembled into a battery module 6. The number of single cells 7 included in the battery module 6 can be one or more, and the specific number can be adjusted according to the application and capacity of the battery module 6.

[0579] If there are multiple single cells 7, the multiple single cells 7 can be connected in series, in parallel, or in a combined series-parallel connection. A combined series-parallel connection means that there are both series and parallel connections among the multiple single cells 7. The multiple single cells 7 can be directly connected in series, in parallel, or in a combined series-parallel connection together, and then the whole formed by the multiple single cells 7 is accommodated in the accommodation part of the battery module 6. Of course, it is also possible that the multiple single cells 7 are first connected in series, in parallel, or in a combined series-parallel connection to form battery modules 6, and then the multiple battery modules 6 are connected in series, in parallel, or in a combined series-parallel connection to form a whole and are accommodated in the accommodation part. Optionally, the battery module 6 can also include an accommodation part with an accommodation space, and the multiple single cells 7 are accommodated in this accommodation space.

[0580] As Figure 26 shown, in some embodiments, the above battery module 6 can also be assembled into a battery pack 2. The number of battery modules 6 included in the battery pack 2 can be adjusted according to the application and capacity of the battery pack. The battery device described herein can be the battery module 6 or the battery pack 2.

[0581] The battery pack 2 can include a box body 5 and multiple battery modules 6 arranged in the box body 5. The box body 5 includes a first box body part 5a and a second box body part 5b. The box body 5 has an accommodation space 5c. The first box body part 5a is used to cover the second box body part 5b and form a closed space for accommodating the battery module 6. The multiple battery modules 6 can be arranged in the box body 5 in any manner.

[0582] The first box body part 5a and the second box body part 5b are covered with each other, and the first box body part 5a and the second box body part 5b jointly define an accommodation space 5c for accommodating the single cells. The second box body part 5b can be a hollow structure with one end open, and the first box body part 5a is a plate-like structure. The first box body part 5a covers the open side of the second box body part 5b to form the box body 5 with the accommodation space 5c. Both the first box body part 5a and the second box body part 5b can also be hollow structures with one side open, and the open side of the first box body part 5a covers the open side of the second box body part 5b to form the box body 5 with the accommodation space 5c. Of course, the first box body part 5a and the second box body part 5b can be in various shapes, such as a cylinder, a cuboid, etc.

[0583] To improve the sealing performance after the connection between the first box body part 5a and the second box body part 5b, a sealing member can also be provided between the first box body part 5a and the second box body part 5b, such as sealant, sealing ring, etc.

[0584] Assume that the first box body part 5a covers the top of the second box body part 5b. The first box body part 5a can also be called the upper box cover, and the second box body part 5b can also be called the lower box body. In some embodiments, during the charging process of the battery pack 2 or any single battery cell constituting the battery pack 2 from the 0% state of charge (SOC) to the 100% state of charge (SOC), the temperature of the external environment where the battery pack 2 is located is 30°C.

[0585] In some embodiments, during the charging process of the battery pack 2 or any single battery cell constituting the battery pack 2 from the 10% state of charge (SOC) to the 80% state of charge (SOC), the temperature of the external environment where the battery pack 2 is located is 30°C.

[0586] In some embodiments, during the charging process of the battery pack 2 or any single battery cell constituting the battery pack 2 from the 10% state of charge to the 80% state of charge, it includes multiple charging steps. The difference between the maximum state of charge of any charging step and the maximum state of charge of its adjacent charging step is less than or equal to 5% state of charge, such as 1% state of charge, 1.5% state of charge, 2% state of charge, 2.5% state of charge, 3% state of charge, 3.5% state of charge, 4% state of charge, 4.5% state of charge, 5% state of charge, or the range composed of any two of the above values.

[0587] The charging process of the battery pack 2 or any single battery cell constituting the battery pack 2 from the 10% state of charge to the 40% state of charge includes multiple charging steps. For any charging step, it can be charged at any rate between 5C and 10C. The charging rate corresponding to each charging step can be any value among 5C, 5.5C, 6C, 6.5C, 7C, 7.5C, 8C, 8.5C, 9C, 9.5C, 10C, or the value within the range composed of any two of the above values.

[0588] The charging process of the battery pack 2 or any single battery cell constituting the battery pack 2 from the 40% state of charge to the 80% state of charge also includes multiple charging steps. The charging rate of any charging step is less than the charging rate of any charging step from the 10% state of charge to the 40% state of charge, and the charging rate of the step when charging to the 80% state of charge is any value between 2.5C and 5C. For example, it can be 2.7C.

[0589] Exemplarily, the charging steps of the battery pack 2 or any single battery cell constituting the battery pack 2 from 10% to 80% can be carried out in the following manner: Constant current charging at 5.0C from 10% SOC to 15% SOC, Constant current charging at 5.0C from 15% SOC to 20% SOC, Charge from 20% SOC to 25% SOC at a constant current of 5.0C, Charge from 25% SOC to 30% SOC at a constant current of 5.0C, Charge from 30% SOC to 35% SOC at a constant current of 5.0C, Charge from 35% SOC to 40% SOC at a constant current of 5.0C, Charge from 40% SOC to 45% SOC at a constant current of 4.6C, Charge from 45% SOC to 50% SOC at a constant current of 4.3C, Charge from 50% SOC to 55% SOC at a constant current of 4.0C, Charge from 55% SOC to 60% SOC at a constant current of 3.7C, Charge from 60% SOC to 65% SOC at a constant current of 3.4C, Charge from 65% SOC to 70% SOC at a constant current of 3.1C, Charge from 70% SOC to 75% SOC at a constant current of 2.9C, Charge from 75% SOC to 80% SOC at a constant current of 2.7C.

[0590] In some embodiments, the charging time of the battery pack 2 or any single cell constituting the battery pack 2 from 10% state of charge to 80% state of charge is less than or equal to 10.5 min, optionally 5 min to 10.5 min. The temperature of the external environment of the battery pack 2 at 10% state of charge is room temperature, such as 30°C. Exemplarily, the charging time of the battery pack 2 from 10% state of charge to 80% state of charge is 10.5 min, 10 min, 9.5 min, 9 min, 8.5 min, 8 min, 7.5 min, 7 min, 6.5 min, 6 min, 5.5 min, 5 min or a range composed of any two of the above values.

[0591] In some embodiments, the volumetric energy density of the single cell can be, but is not limited to, 390 Wh / L to 500 Wh / L, optionally 410 Wh / L to 470 Wh / L. Exemplarily, the volumetric energy density of the single cell is 290 Wh / L, 300 Wh / L, 320 Wh / L, 350 Wh / L, 370 Wh / L, 390 Wh / L, 400 Wh / L, 410 Wh / L, 420 Wh / L, 430 Wh / L, 440 Wh / L, 450 Wh / L, 460 Wh / L, 470 Wh / L, 480 Wh / L, 490 Wh / L, 500 Wh / L or a range composed of any two of the above values. The volumetric energy density of the single cell is relatively high.

[0592] In the embodiments of the present application, the volumetric energy density of a single cell has the meaning well-known in the art and can be detected by using equipment and methods well-known in the art. For example, taking the upper limit voltage of battery charging as 3.65V and the cut-off voltage of battery discharging as 2.0V as an example for illustration, Place the single cell at 25°C, charge it at a constant current of 0.33C until 3.65V, then charge it at a constant voltage until 0.05C, discharge it at a constant current of 0.33C until 2.0V, and record the discharge capacity A0 at this time, unit: Ah. Use a caliper to measure the length, width, and height of the single cell (generally calculated based on the outer shell size of the battery, excluding the height of the electrode terminals and excluding the insulating film outside the outer shell), and calculate the volume V0 of the single cell, unit: L. The volumetric energy density VED of the single cell = (A0 × discharge platform voltage) / V0, unit: Wh / L.

[0593] The volumetric energy density of the single cell is 290 Wh / L to 500 Wh / L, which enables the energy storage unit to store a large amount of electric energy in a limited space, providing a stable and sufficient energy guarantee for the high-power output of the charging module 120. During the process of achieving fast charging, the single cell with high energy density enables the energy storage unit to continuously supply power to the charging module 120, further optimizing the performance of the charging device 100 so that the charging device 100 can operate stably during high-power output.

[0594] Electrical equipment The second aspect of the embodiments of the present application provides an electrical device, which includes the battery device of the embodiments of the present application, such as a single cell, a battery module, or a battery pack. The single cell, the battery module, or the battery pack can be used as the power source of the electrical device or as the energy storage unit of the electrical device. The electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc. The spacecraft includes an airplane, a rocket, a space shuttle, and a spaceship, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal-cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as a drill, an electric grinding wheel, an electric wrench, an electric screwdriver, a hammer drill, an impact drill, a concrete vibrator, and a planer, etc. The embodiments of the present application do not impose special restrictions on the above electrical devices. The electrical device can select a single cell, a battery module, or a battery pack according to its usage requirements.

[0595] Figure 27It is a schematic diagram of the electrical device 1 as an example. The electrical device 1 is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc. To meet the requirements of the electrical device 1 for high power and high energy density, a battery pack or a battery module can be adopted.

[0596] A battery pack 2 is arranged inside the electrical device 1, and the battery pack 2 can be arranged at the bottom, head or tail of the electrical device 1. The battery pack 2 can be used for power supply of the electrical device 1. For example, the battery pack 2 can be used as the operating power supply of the electrical device 1 and can also be used as the driving power supply of the electrical device 1, replacing or partially replacing fuel or natural gas to provide driving power for the electrical device 1.

[0597] The electrical device 1 may further include a controller 3 and a motor 4. The controller 3 is used to control the battery pack 2 to supply power to the motor 4. For example, it is used for the working power requirements during the start, navigation and driving of the electrical device 1.

[0598] As another example, the electrical device can be a mobile phone, a tablet computer, a laptop computer, etc. This electrical device usually requires being thin and light, and a single cell can be used as the power source.

[0599] The charging process of the electrical device can select the following charging methods: Charge from 10% SOC to 15% SOC at a constant current of 5.0C, Charge from 15% SOC to 20% SOC at a constant current of 5.0C, Charge from 20% SOC to 25% SOC at a constant current of 5.0C, Charge from 25% SOC to 30% SOC at a constant current of 5.0C, Charge from 30% SOC to 35% SOC at a constant current of 5.0C, Charge from 35% SOC to 40% SOC at a constant current of 5.0C, Charge from 40% SOC to 45% SOC at a constant current of 4.6C, Charge from 45% SOC to 50% SOC at a constant current of 4.3C, Charge from 50% SOC to 55% SOC at a constant current of 4.0C, Charge from 55% SOC to 60% SOC at a constant current of 3.7C, Charge from 60% SOC to 65% SOC at a constant current of 3.4C, Charge from 65% SOC to 70% SOC at a constant current of 3.1C, Charge from 70% SOC to 75% SOC at a constant current of 2.9C, Charge from 75% SOC to 80% SOC at a constant current of 2.7C.

[0600] In some embodiments, the charging time of the electrical device from 10% state of charge to 80% state of charge is less than or equal to 10.5 min, optionally 5 min to 10.5 min. The temperature of the external environment of the battery pack 2 at 10% state of charge is room temperature, such as 30°C. Exemplarily, the charging time of the battery pack 2 from 10% state of charge to 80% state of charge is 10.5 min, 10 min, 9.5 min, 9 min, 8.5 min, 8 min, 7.5 min, 7 min, 6.5 min, 6 min, 5.5 min, 5 min or a range composed of any two of the above values.

[0601] Embodiment The following embodiments more specifically describe the content disclosed in the embodiments of the present application. These embodiments are only for illustrative purposes, because various modifications and changes within the scope of the content disclosed in the embodiments of the present application are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and all instruments used in the embodiments are commercially available.

[0602] Example 1 1. Preparation of the positive electrode plate The positive electrode plate includes a positive current collector, a positive conductive layer on the pos...

Claims

1. A charging and storage system, characterized in that: A charging device is included, the charging device comprising: An energy storage module, the energy storage module comprising one or more energy storage units, each of the energy storage units having a first positive power supply terminal and a first negative power supply terminal, the one or more energy storage units being connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage module via the first positive power supply terminal and the first negative power supply terminal, and the energy storage module being configured to provide a first direct current; An input module, the input module being adapted to provide charging energy to each of the energy storage units; A charging module, wherein the charging module is connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage module, the charging module is configured to be suitable for charging output based on the first direct current, the maximum charging output power of the charging module is greater than or equal to 350 kilowatts, and / or the rated charging output power of the charging module is greater than or equal to 290 kilowatts, the ratio between the maximum charging output power of the charging module and the maximum output power of the input module is greater than 1 and less than or equal to 15, and / or the ratio between the rated charging output power of the charging module and the rated output power of the input module is greater than 1 and less than or equal to 15, when the number of energy storage units is multiple, the energy storage unit and the charging module are configured to charge electrical equipment with different output powers.

2. The charging and storage system according to claim 1, characterized in that: Each of the energy storage units includes a battery subunit, and the ratio between the rated output power of the input module and the rated energy of the battery subunit is greater than or equal to 1 / n1, wherein the value range of n1 is 1-4.

3. The charging and storage system according to claim 1, characterized in that: Each of the energy storage units includes a battery subunit, and the ratio between the rated energy of the battery subunit and the rated charging output power of the charging module is greater than or equal to 1 / (n2*n3), wherein the value range of n2 is 94%-99%, and the value range of n3 is 4-6.

4. The charging and storage system according to claim 1, characterized in that: Each of the energy storage units includes a battery subunit, the ratio between the rated energy of the battery subunit and the rated power of the battery subunit is less than or equal to 1 / 3, and / or the volume energy density of the battery subunit is greater than or equal to 380 Wh / L.

5. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units includes a battery subunit, the battery subunit includes a single cell, the single cell includes an electrolyte, the electrolyte includes an electrolyte salt, the electrolyte salt includes lithium hexafluorophosphate, and the concentration of the lithium hexafluorophosphate is in the range of 0.5 mol / L-1.0 mol / L.

6. The charging and storage system according to claim 5, characterized in that: The electrolyte further includes an organic solvent, and the organic solvent includes a carbonate solvent.

7. The charging and storage system according to claim 5, characterized in that: The electrolyte salt further includes a fluorine-containing sulfonyl imide salt, and the concentration of the fluorine-containing sulfonyl imide salt is in the range of 0.2 mol / L to 0.5 mol / L.

8. The charging and storage system according to claim 5, characterized in that: The electrolyte further includes an organic solvent, and the organic solvent includes a chain carboxylic acid ester solvent. Based on the total mass of the solvent, the mass content A of the chain carboxylic acid ester solvent satisfies: 5%≤A≤75%, Wherein, the chain carboxylate solvent includes compounds with the following structure: Wherein, R1 includes at least one of a hydrogen atom, a C1-C5 alkyl group or a C1-C5 haloalkyl group, and R2 includes a C1-C5 alkyl group and / or a C1-C5 haloalkyl group.

9. The charging and storage system according to claim 8, characterized in that: 40%≤A≤75%。 10. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units includes a battery subunit, each of which includes a single battery cell, each of which includes a negative electrode plate, each of which includes a negative electrode collector and a negative electrode film layer disposed on at least one side of the negative electrode collector, each of which includes a negative electrode active material, each of which includes a carbon-based material, and each of which includes at least one of natural graphite and artificial graphite.

11. The charging and storage system according to claim 10, characterized in that: The volume average particle size Dv50 of the negative electrode film layer is in the range of 8.2μm-13.5μm; or, the negative electrode film layer includes a first negative electrode active material layer and a second negative electrode active material layer stacked, the first negative electrode active material layer is located on the side close to the negative electrode current collector, the volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer is 9.5μm-18.5μm, and the volume average particle size Dv50 of the negative electrode active material in the second negative electrode active material layer is 7.8μm-14.3μm.

12. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units comprises a battery subunit, wherein the battery subunit comprises a single cell, wherein the single cell comprises a negative electrode plate, wherein the negative electrode plate comprises a negative electrode current collector and a negative electrode film layer at least located on one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material; The compaction density of the negative electrode film layer of the single cell is 1.15 g / cm 3 -1.36g / cm 3 , and / or, the single-sided coating weight of the negative electrode film layer is 0.09g / 1540.25mm 2 -0.17g / 1540.25mm 2 .

13. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units includes a battery subunit, the battery subunit includes a single battery cell, the single battery cell includes a positive electrode plate, the positive electrode plate includes a positive electrode current collector and a positive electrode film layer at least located on one side of the positive electrode current collector, and the positive electrode film layer includes a positive electrode active material; The compaction density of the positive electrode film layer of the single cell is 2.5g / cm 3 -2.8g / cm 3 , and / or, the single-sided coating weight of the positive electrode film layer is 0.2g / 1540.25mm 2 -0.37g / 1540.25mm 2 .

14. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units includes a battery subunit, the battery subunit includes a single cell, the single cell includes a positive electrode plate, the positive electrode plate includes a positive current collector and a positive electrode film layer located at least on one side of the positive current collector, and the thickness of the positive current collector is 10μm-15μm.

15. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units includes a battery subunit, the battery subunit includes a single battery cell, the single battery cell includes a separation membrane, the separation membrane includes a base membrane with a porous structure, and the porosity of the base membrane is 20% to 70%.

16. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units comprises a battery subunit, wherein the battery subunit comprises a positive electrode plate, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode film layer disposed on at least one side of the positive electrode current collector, wherein the positive electrode film layer comprises a positive electrode active material, wherein the positive electrode active material comprises a lithium-containing phosphate; The lithium-containing phosphate includes phosphate particles and a coating layer, wherein the coating layer is coated on at least a portion of the surface of the phosphate particles, and the coating layer includes one or more elements of C, Fe, Ti, Zr, Hf, Ge and Sn.

17. The charging and storage system according to claim 16, characterized in that: The coating layer includes a fast ion conductor, wherein the fast ion conductor includes a general formula of Li 3-d Fe 2-d M 2d (PO4)3 compound, M2 includes at least one element selected from Ti, Zr, Hf, Ge and Sn, 0≤d≤1.

18. The charging and storage system according to any one of claims 1 to 4, characterized in that: Each of the energy storage units comprises a battery subunit, the battery subunit comprises a positive electrode sheet, the positive electrode sheet comprises a positive current collector, a positive conductive layer and a positive film layer, the positive film layer is arranged on at least one side of the positive current collector, the positive conductive layer is located between the positive current collector and the positive film layer, and the thickness of the positive conductive layer is in the range of 0.5 μm-2 μm; and / or Each of the energy storage units includes a battery subunit, which includes a negative electrode plate, and the negative electrode plate includes a negative electrode collector, a negative electrode conductive layer and a negative electrode film layer. The negative electrode film layer is arranged on at least one side of the negative electrode collector, and the negative electrode conductive layer is located between the negative electrode collector and the negative electrode film layer. The thickness of the negative electrode conductive layer is in the range of 0.5μm-2μm.

19. The charging and storage system according to claim 18, characterized in that: The positive electrode conductive layer comprises a positive electrode conductive agent, and the mass content of the positive electrode conductive agent is in the range of 30%-50% based on the total mass of the positive electrode conductive layer; and / or The positive electrode conductive layer includes a positive electrode binder, and based on the total mass of the positive electrode conductive layer, the mass content of the positive electrode binder is in the range of 50%-70%.

20. The charging and storage system according to claim 18, characterized in that: The negative electrode conductive layer comprises a negative electrode conductive agent, and the mass content of the negative electrode conductive agent is in the range of 20%-40% based on the total mass of the negative electrode conductive layer; and / or The negative electrode conductive layer includes a negative electrode binder. Based on the total mass of the negative electrode conductive layer, the mass content of the negative electrode binder is in the range of 60%-80%.

21. The charging and storage system according to claim 1, characterized in that: The one or more energy storage units are connected in series through the first positive power terminal and the first negative power terminal and / or in parallel between the second positive power terminal and the second negative power terminal of the energy storage module to provide the first direct current.

22. The charging and storage system according to claim 21, characterized in that: Each of the energy storage units includes a battery subunit, and each of the energy storage units is configured to provide a second direct current based on the power of the battery subunit.

23. The charging and storage system according to claim 22, characterized in that: At least some of the one or more energy storage units further include a first power conversion subunit, which is connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding battery subunit and energy storage unit, respectively, and is configured to convert the electric energy of the battery subunit into the second direct current; Wherein, in the case where the energy storage unit does not include the first power conversion subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current.

24. The charging and storage system according to claim 23, characterized in that: At least some of the one or more energy storage units further include a first switch subunit, which is connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding battery subunit and the energy storage unit, respectively, and is configured to connect the corresponding battery subunit to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit when it is turned on, so as to provide the second direct current; Wherein, in the case where the energy storage unit does not include the first switch subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current.

25. The charging and storage system according to claim 24, characterized in that: At least some of the one or more energy storage units further include a first power conversion subunit and a first switch subunit, wherein the first power conversion subunit and the first switch subunit are connected in series between the first positive power supply terminal and the first negative power supply terminal of the corresponding battery subunit and the energy storage unit, and the first power conversion subunit is configured to convert the electric energy of the battery subunit into the second direct current when the corresponding first switch subunit is turned on; Wherein, when the energy storage unit does not include the first power conversion subunit and the first switch subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current.

26. The charging and storage system according to any one of claims 23 to 25, characterized in that: The input module includes an input interface, which is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module and is configured to provide charging energy for each energy storage unit based on the third direct current provided by the first external power supply; or The input module includes a second power conversion subunit, which is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module and is configured to provide charging energy to each of the energy storage units based on the first alternating current provided by the second external power supply.

27. The charging and storage system according to claim 26, characterized in that: The charging module includes a third power conversion subunit and a charging gun, the positive input terminal and the negative input terminal of the third power conversion subunit are correspondingly connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, the positive output terminal and the negative output terminal of the third power conversion subunit are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun, and the third power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

28. The charging and storage system according to claim 26, characterized in that: The charging module includes a fourth power conversion subunit and a charging gun, the positive input end of the fourth power conversion subunit is connected to the second positive power supply end of the energy storage module, the positive output end of the fourth power conversion subunit is connected to the positive input end of the charging gun, and the negative input end of the charging gun is connected to the second negative power supply end of the energy storage module. The fourth power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

29. The charging and storage system according to any one of claims 23 to 25, characterized in that: The energy storage module also includes a selection unit, which is connected to the one or more energy storage units and is configured to select at least one energy storage unit from the one or more energy storage units and connect it to the second positive power supply terminal and the second negative power supply terminal of the energy storage module to provide the first direct current.

30. The charging and storage system according to claim 29, characterized in that: The energy storage module includes one second positive power supply terminal and one second negative power supply terminal, the selection unit includes multiple second switch sub-units, each of the second switch sub-units is connected to one of the energy storage units, each of the second switch sub-units is connected in series between the first positive power supply terminal of the corresponding energy storage unit and the second positive power supply terminal of the energy storage module, the first negative power supply terminals of the one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module, and the second switch sub-unit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the second positive power supply terminal of the energy storage module when it is turned on.

31. The charging storage system according to claim 30, characterized in that: The charging module includes a fifth power conversion subunit and a charging gun, the positive input terminal and the negative input terminal of the fifth power conversion subunit are correspondingly connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, the positive output terminal and the negative output terminal of the fifth power conversion subunit are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun, and the fifth power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

32. The charging storage system according to claim 30, characterized in that: The charging module includes a sixth power conversion subunit and a charging gun, the positive input end of the sixth power conversion subunit is connected to the second positive power supply end of the energy storage module, the positive output end of the sixth power conversion subunit is connected to the positive input end of the charging gun, and the negative input end of the charging gun is connected to the second negative power supply end of the energy storage module. The sixth power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

33. The charging storage system according to claim 32, characterized in that: The energy storage module includes multiple second positive power supply terminals, the energy storage module includes one second negative power supply terminal, the selection unit includes multiple second switch sub-units, each of the second switch sub-units is connected to one of the energy storage units and one of the second positive power supply terminals, each of the second switch sub-units is connected in series between the first positive power supply terminal and the corresponding second positive power supply terminal of the corresponding energy storage unit, the first negative power supply terminals of the one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module, and the second switch sub-unit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the corresponding second positive power supply terminal when it is turned on.

34. The charging storage system according to claim 33, characterized in that: The charging module includes multiple seventh power conversion sub-units and a charging gun, the positive input terminal and the negative input terminal of each of the seventh power conversion sub-units are correspondingly connected to one of the second positive power supply terminals and the second negative power supply terminals, the positive output terminal and the negative output terminal of each of the seventh power conversion sub-units are correspondingly connected to the positive input terminal and the negative input terminal of the charging gun, and the multiple seventh power conversion sub-units are configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

35. The charging storage system according to claim 33, characterized in that: The charging module includes multiple eighth power conversion sub-units, and the positive input terminal of each of the eighth power conversion sub-units is connected to one of the second positive power supply terminals, the positive output terminal of each of the eighth power conversion sub-units is connected to the positive input terminal of the charging gun, and the negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The multiple eighth power conversion sub-units are configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

36. The charging storage system according to claim 29, characterized in that: The input module includes a ninth power conversion subunit, which is connected to the one or more energy storage units and is configured to provide charging energy to each of the energy storage units based on the first alternating current provided by the second external power source.

37. The charging storage system according to claim 29, characterized in that: The input module includes a plurality of tenth power conversion subunits, each of which is connected to one of the energy storage units, and the plurality of tenth power conversion subunits are configured to provide charging energy to each of the energy storage units based on the first alternating current provided by the second external power supply.

38. The charging and storage system according to any one of claims 1 to 4, characterized in that: The charging device includes multiple charging devices, and the multiple charging devices share a DC bus or an AC bus.

39. The charging storage system according to claim 38, characterized in that: In the case where a plurality of charging devices share one DC bus and the input module of the charging device includes an input interface, the system further includes: a first transformer, wherein a primary winding of the first transformer is connected to an AC power grid and is configured to convert a second AC power provided by the AC power grid into a first AC power; a first AC-DC conversion module, the first AC-DC conversion module being connected to the secondary winding of the first transformer and the DC bus respectively, and being configured to convert the first AC power into a third DC power; Wherein, the second positive power supply terminal and the second negative power supply terminal of the energy storage modules in the plurality of charging devices are both connected to the DC bus.

40. The charging storage system according to claim 38, characterized in that: In the case where a plurality of charging devices share one DC bus and the input module of the charging device includes a second power conversion subunit, the system further includes: a first transformer, wherein the primary winding of the first transformer is connected to an AC power grid, the second power conversion subunit is connected to a secondary winding of the first transformer and the DC bus, respectively, and the first transformer is configured to convert a second AC power provided by the AC power grid into a first AC power; Wherein, the second positive power supply terminal and the second negative power supply terminal of the energy storage modules in the plurality of charging devices are both connected to the DC bus.

41. The charging storage system according to claim 38, characterized in that: In the case where a plurality of charging devices share one AC bus and the input modules of the charging devices include a ninth power conversion subunit or a plurality of tenth power conversion subunits, the system further includes: a second transformer, wherein a primary winding of the second transformer is connected to the AC power grid, a secondary winding of the second transformer is connected to the AC bus, and the second transformer is configured to convert a second AC power provided by the AC power grid into a first AC power; Wherein, the ninth power conversion subunits of the input modules in the plurality of charging devices or the plurality of the tenth power conversion subunits are all connected to the AC bus.

42. The charging and storage system according to any one of claims 23 to 25, characterized in that: The charging device further includes a wireless communication module, and at least part of the energy storage module, the input module and the charging module are connected to the wireless communication module so as to perform information exchange with an external device through the wireless communication module.

43. A charging pile, characterized in that: Comprising a charging and storage system according to any one of claims 1-42.

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