Charging devices and charging piles

Abstract

The present application discloses a charging device and a charging pile. The charging device includes: an energy storage module, the energy storage module includes one or more energy storage units, each energy storage unit has a first positive power supply terminal and a first negative power supply terminal, the 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 through the first positive power supply terminal and the first negative power supply terminal, and the energy storage module is configured to provide a first direct current; a charging module, the charging module is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, and 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. In this way, by configuring the energy storage unit inside the charging device, not only high-power charging, such as supercharging / fast charging, can be achieved, but also the cost is low.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from the following patent applications, the entire contents of which are incorporated herein by reference:

[0003] PCT international patent application number PCT / CN2024 / 093513, entitled “Charging Device, Charging Pile, and Charging Storage System,” filed on May 15, 2024;

[0004] PCT international patent application with application number PCT / CN2024 / 102652 and name “Battery Cell, Battery and Electrical Device” submitted on June 28, 2024. Technical Field

[0005] The present application relates to the field of charging technology, and in particular to a charging device and a charging pile. Background Art

[0006] At present, fast charging / super charging piles are less used, but with the popularization of fast charging / super charging electric vehicles, a large number of fast charging / super charging piles are urgently needed.

[0007] However, the fast charging / super charging piles in the related technologies all require additional configuration of transformers or transformer expansion, which is not conducive to the rapid access of fast charging / super charging piles and will increase more costs. Summary of the Invention

[0008] In view of the above problems, the present application provides a charging device and a charging pile. Without the need for additional transformer configuration or transformer expansion, by configuring an energy storage unit inside the charging device, not only can the charging device be quickly charged, such as fast charging / super charging, but the cost caused by adding a new transformer or expanding the transformer capacity can also be reduced.

[0009] In a first aspect, the present application provides a charging device, comprising: an energy storage module, the energy storage module comprising one or more energy storage units, each energy storage unit 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, the energy storage module being configured to provide a first direct current; a charging module, the charging module being connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, the charging module being configured to output charging based on the first direct current, the maximum charging output power of the charging module being greater than or equal to 350 kilowatts, and / or the rated charging output power of the charging module being greater than or equal to 290 kilowatts; and an input module, the input module being adapted to provide charging energy to each energy storage unit;

[0010] When there are multiple energy storage units, the energy storage units and the charging module are configured to charge the electrical device with different charging output powers;

[0011] The ratio of the maximum charging output power of the charging module to the maximum output power of the input module is greater than 1 and less than or equal to 15, and / or the ratio of the rated charging output power of the charging module to the rated output power of the input module is greater than 1 and less than or equal to 15.

[0012] In the technical solution of the embodiment of the present application, by configuring an energy storage unit inside the charging device, without the need for additional transformer configuration or transformer expansion, not only can the fast charging of the charging device, such as fast charging / supercharging, be achieved, but also the cost caused by adding a new transformer or expanding the transformer can be reduced. The energy storage unit and the charging module are configured to charge the electrical equipment with different charging output powers. 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, which can reduce the current shock, overheating and other problems caused by the instantaneous excessive power input to the charging module. At the same time, the input module can charge the energy storage module with low power, and the energy storage module then outputs controllable high power to the charging module, realizing low power input to the energy storage module and high power output from the charging module. In addition, the energy storage module 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 can reasonably distribute electrical energy, reduce unnecessary energy consumption, improve the cost-effectiveness of the charging device, and enable the charging device to operate smoothly when the power input is small and the power output is large.

[0013] In some embodiments, the maximum output power of the input module is less than or equal to 150 kilowatts, and / or the rated output power of the input module is less than or equal to 125 kilowatts.

[0014] Limiting the maximum output power and / or rated power of the input module to the above range allows the charging device to be flexibly connected to the power network. Specifically, since the output power of most public power grids or commercial power interfaces is limited, the power setting of the input module can smoothly obtain charging energy from the conventional power environment without modifying the existing power supply lines, thereby improving the access feasibility of the charging device in various power consumption scenarios and facilitating the installation of the charging device. In addition, it can achieve high-power charging of the charging device with low power input. During peak power consumption, when multiple power devices are running at the same time, the energy storage module supplies power to multiple power devices, and the input module stably charges the energy storage unit at a lower power, which can effectively reduce the impact of the charging device on the power grid during the charging process and help maintain the stability of the power grid.

[0015] In some embodiments, each energy storage unit includes a battery subunit, and a ratio between a rated output power of the input module and a rated energy of the battery subunit is greater than or equal to 1 / n1, where n1 ranges from 1 to 4.

[0016] Therefore, by stipulating 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 1 is small, the rated energy of the battery subunit is small, so that the input power and the rated energy of the battery subunit are matched, and the output module will not charge the battery subunit too slowly, affecting the use of the energy storage unit; at the same time, stipulating 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, achieving small power input and high power output, and improving user experience.

[0017] 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 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.

[0018] This ensures charging performance while also ensuring the reliability of the charging device. When the rated energy of the battery subunit matches the rated charging output power of the charging module, the battery subunit can stably provide energy to the charging module during the charging process, reducing charging power instability or interruptions caused by insufficient energy supply. Taking n2 as an example, with a value of 94% and n3 as 6, the larger denominator requires the battery subunit to have a relatively high rated energy to match the power of the charging module. This allows the charging device to operate continuously and stably during long-term, high-power charging, reduces the probability of failure, lowers maintenance costs, and improves the cost-effectiveness of the charging device in terms of its service life.

[0019] In some embodiments, each energy storage unit 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 watt-hours / liter.

[0020] When the charging device outputs high power (the maximum charging output power of the charging module is above 350kW), the rated energy of the battery subunit is matched with the rated power, reducing grid fluctuations caused by the need for grid power supply due to insufficient rated energy of the battery subunit caused by high-power output. This is beneficial to improving the reliability and stability of the charging device. When the power output is high, the charging device can operate continuously and stably, reducing the probability of failure and lowering maintenance costs, thereby improving the cost-effectiveness from the perspective of the service life of the charging device.

[0021] In some embodiments, each energy storage unit 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 lithium hexafluorophosphate is in the range of 0.5 mol / L-1.0 mol / L.

[0022] By providing the electrolyte with lithium hexafluorophosphate at the above-mentioned concentration, the battery subunit has a higher ionic conductivity, thereby improving the charging rate of the charging device, and also making the battery subunit have higher interface stability and higher thermal stability; lithium hexafluorophosphate has a smaller effect on the severity of thermal runaway, so that the battery subunit has a suitable severity of thermal runaway and a lower risk of thermal diffusion, so that the charging device has higher reliability at a power output of more than 350 kW.

[0023] In some embodiments, the electrolyte further includes an organic solvent, and the organic solvent includes a carbonate solvent.

[0024] Adding carbonate solvents to the electrolyte can improve various properties of the battery subunits, for example, the charge and discharge efficiency, cycle performance, low temperature performance and high voltage stability of the battery subunits.

[0025] In some embodiments, the electrolyte salt further comprises 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-0.5 mol / L.

[0026] Since the fluorinated sulfonyl imide salt has the characteristics of low viscosity and high ionic conductivity, the electrolyte including the fluorinated sulfonyl imide salt at the above concentration is beneficial to improving the charging rate of the battery subunits, thereby improving the charging rate of the charging device.

[0027] In some embodiments, the electrolyte further includes an organic solvent, the organic solvent includes a chain carboxylate solvent, and the mass content A of the chain carboxylate solvent, based on the total mass of the solvent, satisfies: 5%≤A≤75%,

[0028] Among them, the chain carboxylate solvents include compounds with the following structures:

[0029]

[0030] 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.

[0031] In this technical solution, the solvent includes a carboxylic acid ester solvent, so that the electrolyte can have higher ionic conductivity and relatively low viscosity, which is conducive to further improving the fast charging performance of the charging device, such as fast charging performance and / or supercharging performance.

[0032] In some embodiments, 40%≤A≤75%.

[0033] 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.

[0034] 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 plate, the negative electrode plate includes a negative electrode collector and a negative electrode film layer arranged on at least one side of the negative electrode collector, the negative electrode film layer includes a negative electrode active material, 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.

[0035] Carbon-based materials using at least one of natural graphite and artificial graphite as the negative electrode active material, both of which have excellent conductivity and high theoretical specific capacity. Natural graphite has high crystallinity and a regular layered structure, which facilitates the rapid insertion and extraction of lithium ions, thereby improving battery charge and discharge efficiency. Artificial graphite can precisely adjust its microstructure and performance through controlled production processes, enhancing battery cycle stability and extending battery life.

[0036] 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.

[0037] Therefore, this particle size range strikes a balance between specific surface area and compaction density. Smaller particle sizes provide larger specific surface area, increasing lithium ion reaction sites and improving the battery's charge and discharge rate performance; while appropriate particle sizes ensure higher compaction density, reducing the gaps between active materials and increasing the battery's energy density, thus achieving a better balance between rate performance and energy density.

[0038] 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 together, 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.

[0039] 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, the solid phase transmission path of lithium ions can be shortened, thereby improving the fast charging performance. On the other hand, the materials are less likely to agglomerate during the preparation process, thereby improving the stability of the materials. The combination 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 conducive to establishing a gradient porosity 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.

[0040] 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 plate, the negative electrode plate includes a negative electrode current collector and a negative electrode film layer located at least on one side of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material layer.

[0041] The compaction density of the negative electrode film layer of the single cell at 100% charge is 1.15g / 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 .

[0042] When the compaction density of the negative electrode film layer is within the above range, it is beneficial to improve the energy density of the battery cell. Because the negative electrode active material in the negative electrode film layer is densely packed, the contact resistance between particles is low, which can further reduce the resistance of the electrode sheet and thus reduce heat generation. When the single-sided coating weight of the negative electrode film layer is within the above range, the heat generation per unit area of ​​the negative electrode sheet is not excessive, while also achieving an improvement in the energy density of the battery cell.

[0043] In some embodiments, each energy storage unit 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 located at least on one side of the positive electrode current collector, and the positive electrode film layer includes a positive electrode active material layer;

[0044] When the single cell is 100% charged, the compaction density of the positive electrode film is 2.5g / cm 3 -2.8g / cm 3 .

[0045] 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 battery cell. Moreover, since the positive electrode active material in the positive electrode film layer is stacked relatively densely and the contact resistance between particles is small, the resistance of the electrode sheet can be further reduced, thereby reducing heat generation.

[0046] In some embodiments, the single-sided coating weight of the positive electrode film layer is 0.2 g / 1540.25 mm 2 -0.37g / 1540.25mm 2 .

[0047] When the single-sided coating weight of the positive electrode film layer is within the above range, the heat generated per unit area of ​​the positive electrode sheet will not be too large, and the energy density of the battery cell can be improved.

[0048] 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 plate, the positive electrode plate includes a positive electrode collector and a positive electrode film layer located at least on one side of the positive electrode collector, and the thickness of the positive electrode collector is 10μm-15μm.

[0049] When the thickness of the positive electrode current collector is within the above range, the positive electrode current collector has a relatively excellent current flow capacity and can enable the battery cell to have a higher energy density.

[0050] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a single battery cell, the single battery cell includes an isolation membrane, the isolation membrane includes a base membrane with a porous structure, and the porosity of the base membrane is 20% to 70%.

[0051] When the porosity of the base film is within the above range, the migration ability of lithium ions in the separator can be improved, and the internal resistance of the battery cell can be reduced, thereby reducing heat generation.

[0052] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a positive electrode plate, the positive electrode plate includes a positive electrode current collector and a positive electrode film layer disposed 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;

[0053] The lithium-containing phosphate includes phosphate particles and a coating layer, 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 selected from the group consisting of C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0054] Under this technical solution, the positive electrode coating layer has excellent ion and electron conductivity, which can improve the ionic conductivity and electronic conductivity of the positive electrode active material, thereby effectively increasing the charging rate of the battery sub-unit and improving the fast charging performance of the charging device, which is beneficial to improving the fast charging performance of the battery device.

[0055] In some embodiments, the coating layer includes a fast ion conductor, wherein the fast ion conductor includes a general formula of Li 3-d Fe 2- d M2d (PO4)3 compound, M2 includes at least one element selected from Ti, Zr, Hf, Ge and Sn, 0≤d≤1.

[0056] Since fast ion conductors have high ionic conductivity, they are conducive to the diffusion and transmission of lithium ions. This can further increase the charging rate of the battery subunits, improve the fast charging performance of the charging device, and help improve the fast charging performance of the battery device.

[0057] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a positive electrode plate, the positive electrode plate includes a positive electrode collector, a positive electrode conductive layer and a positive electrode film layer, the positive electrode film layer is arranged on at least one side of the positive electrode collector, the positive electrode conductive layer is located between the positive electrode collector and the positive electrode film layer, and the thickness of the positive electrode conductive layer is in the range of 0.5μm-2μm.

[0058] 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 improving the fast charging performance of the battery device.

[0059] In some embodiments, the positive electrode conductive layer includes 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.

[0060] This technical solution sets the mass content of the positive electrode conductive agent in the range of 30%-50%, which can improve the electron transmission efficiency in the positive electrode sheet and thus improve the rate performance of the battery sub-unit.

[0061] In some embodiments, the positive electrode conductive layer includes a positive electrode binder, and the mass content of the positive electrode binder is in the range of 50%-70% based on the total mass of the positive electrode conductive layer.

[0062] This technical solution sets the mass content of the positive electrode binder in the range of 50%-70%, which can reduce the possibility of cracking or peeling of the positive electrode sheet during the cycle process, thereby improving the cycle life of the battery sub-unit.

[0063] In some embodiments, each energy storage unit includes a battery subunit, the battery subunit includes a negative electrode plate, 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, the negative electrode conductive layer is located between the negative electrode collector and the negative electrode film layer, and the thickness of the negative electrode conductive layer is in the range of 0.5μm-2μm.

[0064] 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 improving the fast charging performance of the battery device.

[0065] In some embodiments, the negative electrode conductive layer includes 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.

[0066] This technical solution sets the mass content of the negative electrode conductive agent in the range of 20%-40%, which can improve the electron transmission efficiency in the negative electrode plate, thereby improving the rate performance of the battery sub-unit, which is beneficial to improving the fast charging performance of the battery device.

[0067] In some embodiments, the negative electrode conductive layer includes a negative electrode binder, and the mass content of the negative electrode binder is in the range of 60%-80% based on the total mass of the negative electrode conductive layer.

[0068] This technical solution sets the mass content of the negative electrode adhesive in the range of 60%-80%, which can reduce the possibility of cracking or peeling of the negative electrode sheet during the cycle process, thereby increasing the cycle life of the battery sub-unit and helping to improve the cycle life of the battery device.

[0069] In some embodiments, each energy storage unit includes a battery subunit, and each energy storage unit is configured to provide the second direct current based on the power of the battery subunit.

[0070] In some embodiments, 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 electrical energy of the battery subunit into a second direct current. If 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. This improves charging flexibility.

[0071] In some embodiments, 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 conducting to provide a second direct current. If 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. In this way, the energy storage unit can be protected.

[0072] 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 being 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. Where 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. This improves charging flexibility and protects the energy storage unit.

[0073] In some embodiments, the first power conversion subunit is a bidirectional DC / DC subunit, so as to realize charging and discharging of the battery subunit.

[0074] In some embodiments, the input module includes an input interface connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module and configured to provide charging energy to 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 connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module and configured to provide charging energy to each energy storage unit based on the first alternating current provided by the second external power supply. In this way, either AC input or DC input can be used to charge the energy storage unit.

[0075] In some embodiments, the charging module includes a third power conversion subunit and a charging gun. The positive input and negative input terminals 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 and negative output terminals of the third power conversion subunit are correspondingly connected to the positive input and negative input terminals of the charging gun. The third power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output via the charging gun. In this way, the charging guns do not share a common negative load.

[0076] 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, and 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 DC power into a fourth DC power for charging output via the charging gun. In this way, the charging guns share a common load, which can reduce costs.

[0077] In some embodiments, the energy storage module further includes a selection unit connected to one or more energy storage units and 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. This improves charging flexibility.

[0078] In some embodiments, 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 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 terminal of one or more energy storage units is 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.

[0079] In some embodiments, the charging module includes a fifth power conversion subunit and a charging gun. The positive input and negative input of the fifth power conversion subunit are connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, respectively. The positive output and negative output of the fifth power conversion subunit are connected to the positive input and negative input of the charging gun, respectively. The fifth power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output via the charging gun. In this way, the charging guns do not share a common load.

[0080] In some embodiments, the charging module includes a sixth power conversion subunit and a charging gun. The positive input terminal of the sixth power conversion subunit is connected to the second positive power supply terminal of the energy storage module, the positive output terminal of the sixth power conversion subunit 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 sixth power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output via the charging gun. In this way, the charging guns share a common load, which can reduce costs.

[0081] In some embodiments, 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 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 and the corresponding second positive power supply terminal of the corresponding energy storage unit, the first negative power supply terminal of one or more energy storage units is 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.

[0082] In some embodiments, the charging module includes multiple seventh power conversion subunits and a charging gun. The positive input terminal and negative input terminal of each seventh power conversion subunit are respectively connected to a second positive power supply terminal and a second negative power supply terminal. The positive output terminal and negative output terminal of each seventh power conversion subunit are respectively connected to the positive input terminal and negative input terminal of the charging gun. The multiple seventh power conversion subunits are configured to convert the first direct current into a fourth direct current for charging output via the charging gun. In this way, the charging guns do not share a common negative load.

[0083] In some embodiments, the charging module includes multiple 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, the positive output terminal of each eighth power conversion subunit 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 subunits are configured to convert the first direct current into a fourth direct current for charging output via the charging gun. In this way, the charging guns share a common negative load, which can reduce costs.

[0084] In some embodiments, the input module includes a ninth power conversion subunit, which is connected to one or more energy storage units and configured to provide charging energy to each energy storage unit based on the first AC power provided by the second external power source. In this manner, the energy storage units are charged using a single power conversion subunit.

[0085] In some embodiments, the second external power source is a three-phase AC power source, and the ninth power conversion subunit is a bidirectional three-phase ACDC subunit. In this way, three-phase power access can be achieved through three energy storage units and one power conversion subunit.

[0086] In some embodiments, the input module includes a plurality of tenth power conversion subunits, each of which is connected to an energy storage unit. The plurality of tenth power conversion subunits are configured to provide charging energy to each energy storage unit based on the first AC power provided by the second external power source. In this manner, the energy storage unit is charged via the plurality of power conversion subunits.

[0087] In some embodiments, the second external power source is a three-phase AC power source, and the tenth power conversion subunit includes three, each of which is a bidirectional single-phase ACDC subunit. In this way, three-phase power access can be achieved through three energy storage units and three power conversion subunits.

[0088] 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 are connected to the wireless communication module to exchange information with external devices through the wireless communication module.

[0089] In a second aspect, the present application provides a charging pile, comprising the aforementioned charging device.

[0090] In a third aspect, the present application provides a charging and storage system, including the aforementioned charging device.

[0091] In some embodiments, the charging device includes multiple charging devices, and the multiple charging devices share a DC bus or an AC bus.

[0092] In some embodiments, when multiple charging devices share a DC bus and the input modules of the charging devices include input interfaces, the system further includes: a first transformer, the primary winding of the first transformer being connected to the AC grid and configured to convert a second AC power provided by the AC 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 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 multiple charging devices are both connected to the DC bus. In this way, a common DC bus is achieved for the multiple charging devices.

[0093] In some embodiments, when multiple charging devices share a common DC bus and the input modules of the charging devices include a second power conversion subunit, the system further includes: a first transformer, the primary winding of the first transformer being connected to the AC power grid; the second power conversion subunit being connected to the secondary winding of the first transformer and the DC bus, respectively; the first transformer being configured to convert the second AC power provided by the AC power grid into the first AC power; wherein the second positive power supply terminal and the second negative power supply terminal of the energy storage modules in the multiple charging devices are both connected to the DC bus. In this way, a common DC bus is achieved for the multiple charging devices.

[0094] In some embodiments, when multiple charging devices share a common AC bus and the input modules of the charging devices include a ninth power conversion subunit or multiple tenth power conversion subunits, the system further includes: a second transformer, wherein the primary winding of the second transformer is connected to the AC grid, the secondary winding of the second transformer is connected to the AC bus, and the second transformer is configured to convert the second AC power provided by the AC grid into the first AC power; wherein the ninth power conversion subunit or multiple tenth power conversion subunits of the input modules of the multiple charging devices are all connected to the AC bus. In this way, a common AC bus is achieved for the multiple charging devices.

[0095] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0097] Figure 1 This is a schematic structural diagram of a charging device with energy storage units connected in series according to an embodiment of the present application.

[0098] Figure 2 This is a schematic structural diagram of a charging device with an input module according to an embodiment of the present application.

[0099] Figure 3 This is a schematic structural diagram of a charging device with energy storage units connected in parallel according to an embodiment of the present application.

[0100] Figure 4a This is a schematic structural diagram of an energy storage unit according to an embodiment of the present application, including a charging device for a battery subunit.

[0101] Figure 4b This is a structural schematic diagram of a charging device in which an energy storage unit according to an embodiment of the present application includes a battery subunit and a first power conversion subunit.

[0102] Figure 4c This is a schematic structural diagram of a charging device in which an energy storage unit according to an embodiment of the present application includes a battery subunit and a first switch subunit.

[0103] Figure 4d This is a structural diagram of a charging device in which an energy storage unit according to an embodiment of the present application includes a battery subunit, a first power conversion subunit and a first switch subunit.

[0104] Figure 5a This is a structural diagram of a charging device including an input interface in an input module according to an embodiment of the present application.

[0105] Figure 5b This is a structural diagram of a charging device in which an input module according to an embodiment of the present application includes a second power conversion sub-unit.

[0106] Figure 6a This is a schematic structural diagram of a charging device in which charging guns do not share a common load according to an embodiment of the present application.

[0107] Figure 6b This is a schematic structural diagram of a charging device for charging guns sharing a common load according to an embodiment of the present application.

[0108] Figure 7 Schematic diagram of the structure of a charging device with a selection unit according to an embodiment of the present application.

[0109] Figure 8 for Figure 7 A schematic structural diagram of a charging device having a second positive power supply terminal is shown.

[0110] Figure 9a for Figure 8 The diagram shows the structure of a charging device with a second positive power supply terminal and charging guns that do not share a negative connection.

[0111] Figure 9b for Figure 8 The diagram shows the structure of a charging device with a second positive power supply terminal and a common negative charging terminal for charging guns.

[0112] Figure 10 for Figure 7 A schematic structural diagram of a charging device having multiple second positive power supply terminals is shown.

[0113] Figure 11a for Figure 10 The diagram shows the structure of a charging device with multiple second positive power supply terminals and charging guns that do not share a common negative terminal.

[0114] Figure 11b for Figure 10 The diagram shows the structure of a charging device with multiple second positive power terminals and a common negative charging gun.

[0115] Figure 12a for Figure 7 A schematic structural diagram of a charging device having a selection unit and an input module including a ninth power conversion subunit is shown.

[0116] Figure 12b for Figure 7 A schematic structural diagram of a charging device having a selection unit and an input module including a plurality of tenth power conversion sub-units is shown.

[0117] Figure 13 This is a structural diagram of a charging device with a wireless communication module according to an embodiment of the present application.

[0118] Figure 14 This is a structural 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 the same load.

[0119] Figure 15 This is a structural diagram of a charging device in which energy storage units are connected in series, and each energy storage unit includes a bidirectional DCDC sub-unit and a charging gun that shares the same load.

[0120] Figure 16This is a structural diagram of a charging device in which energy storage units are connected in parallel in one embodiment of the present application, each energy storage unit includes a bidirectional DCDC sub-unit, and charging guns do not share the same load.

[0121] Figure 17 This is a structural diagram of a charging device in which energy storage units are connected in parallel in one embodiment of the present application, and each energy storage unit includes a bidirectional DCDC sub-unit and a charging gun that shares the same load.

[0122] Figure 18 This is a structural diagram of a charging device in which energy storage units are connected in series, some energy storage units include bidirectional DCDC sub-units, and charging guns do not share the same load.

[0123] Figure 19 This is a structural diagram of a charging device in which energy storage units are connected in series and some energy storage units include bidirectional DCDC sub-units and charging guns that share the same load.

[0124] Figure 20 This is a structural diagram of a charging device in which energy storage units are connected in parallel according to an embodiment of the present application, each energy storage unit includes a first switch sub-unit, and charging guns do not share the same load.

[0125] Figure 21 This is a schematic structural diagram of a charging device in which an energy storage unit and a bidirectional ACDC subunit constitute three-phase electricity and the charging guns do not share the same load according to an embodiment of the present application.

[0126] Figure 22 This is a structural diagram of a charging device in which an energy storage unit and a bidirectional ACDC subunit constitute three-phase electricity and the charging guns share the same load according to an embodiment of the present application.

[0127] Figure 23 A schematic diagram of the structure of a single battery cell provided in some embodiments of the present application.

[0128] Figure 24 Schematic diagram of an explosion of a single battery cell provided in some embodiments of the present application.

[0129] Figure 25 A schematic structural diagram of a battery module provided in some embodiments of the present application.

[0130] Figure 26 A schematic diagram of the structure of a battery pack provided in some embodiments of the present application.

[0131] Figure 27 It is a structural diagram of electrical equipment provided in some embodiments of the present application.

[0132] Figure 28 This is a schematic structural diagram of a charging pile according to an embodiment of the present application.

[0133] Figure 29 This is a structural diagram of a charging and storage system according to an embodiment of the present application.

[0134] Figure 30 This is a structural diagram of a charging and storage system in which multiple charging devices share a DC bus according to an embodiment of the present application.

[0135] Figure 31 This is a structural diagram of a charging and storage system in which multiple charging devices share a DC bus according to another embodiment of the present application.

[0136] Figure 32 This is a structural diagram of a charging and storage system in which multiple charging devices share a common AC bus according to one embodiment of the present application.

[0137] The following are the descriptions of the reference numerals:

[0138] 100, charging device; 110, energy storage module; 120, charging module; 121, third power conversion subunit; 122, charging gun; 123, fourth power conversion subunit; 124, fifth power conversion subunit; 125, sixth power conversion subunit; 130, input module; 140, wireless communication module; 111, selection unit; 210, first external power source; 220, second external power source; 131, second power conversion subunit; 132, ninth power conversion subunit;

[0139] 1. Electrical equipment; 2. Battery pack; 3. Controller; 4. Motor; 5. Box; 5a. First box portion; 5b. Second box portion; 5c. Accommodation space; 6. Battery module;

[0140] 7. Single cell;

[0141] 10. Electrode assembly; 11. First electrode tab; 13. Second electrode tab; 12. Main body;

[0142] 20. Housing; 21. Shell; 22. End cover;

[0143] 31. First electrode terminal; 32. Second electrode terminal. DETAILED DESCRIPTION

[0144] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0145] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0146] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0147] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0148] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0149] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0150] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0151] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0152] At present, fast charging / super charging piles are less used, but with the popularization of fast charging / super charging electric vehicles, a large number of fast charging / super charging piles are urgently needed.

[0153] However, the fast charging / super charging piles in the related art all require additional transformers or transformer expansion, which is not conducive to the rapid access of fast charging / super 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 / super charging pile, it is necessary to expand the transformer or add a new transformer between the original transformer and the fast charging / super charging pile. However, since the transformer needs to be expanded or added, it is not conducive to the rapid access of fast charging / super charging piles and will increase costs.

[0154] Based on this, the present application provides a charging device that, by configuring an energy storage unit inside the charging device without the need for additional transformer configuration or transformer expansion, can not only achieve fast charging of the charging device, such as fast charging / super charging, but also reduce the cost caused by adding a new transformer or expanding the transformer capacity.

[0155] The charging device disclosed in the embodiment of the present application can be used to charge electric vehicles, electric ships, electric tools and other equipment that require fast charging / supercharging, and can also be used to charge electric vehicles, electric ships, electric tools and other equipment that do not require fast charging / supercharging. In other words, the charging device disclosed in the embodiment of the present application can realize high-power and low-power charging of electrical equipment, and has a wide range of applications.

[0156] The charging device of the present application is described below with reference to specific embodiments.

[0157] Figure 1 Schematic diagram of the structure of a charging device 100 according to an embodiment of the present application.

[0158] Reference Figure 1 The charging device 100 may include: an energy storage module 110 and a charging module 120 .

[0159] 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 terminal (+) and a first negative power terminal (-). 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 110 via the first positive power terminal and the first negative power terminal. The energy storage module 110 is configured to provide a first direct current. As an example, the energy storage unit can be an electrical box.

[0160] 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.

[0161] 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 units, which can meet the low-power charging application scenario; when the charging device 100 is used for high-power charging, the energy storage unit can be set to multiple units, which can meet the high-power and low-power charging application scenarios. 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 be used for 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 rapid access can be achieved to achieve high-power charging without adding a transformer or expanding the transformer capacity.

[0162] 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, 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 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. During charging, the energy storage module 110 provides a 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 actual conditions, and the charging requirements can be met through reasonable parameter configuration.

[0163] When there are multiple energy storage units, the multiple energy storage units can be connected in series, in parallel, or in series-parallel, and 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. Figure 1In the example, energy storage units A1, ..., An-1, and An are connected in series between the second positive and second negative power supply terminals of energy storage module 110 via their respective first positive and first negative power supply terminals. The second positive and second negative power supply terminals of energy storage module 110 are also connected to charging module 120. During charging, when high-power charging is required, energy storage module 110 provides a first DC power from multiple energy storage units. This first DC power can have a high power. Charging module 120 then converts this first DC power to a target DC power for charging the device to be charged. This target DC power has a high power, thus meeting high-power charging scenarios. When low-power charging is required, the first DC power can have a low power, while the target DC power also has a low power, thus meeting low-power charging scenarios. It should be noted that the relevant parameters of the energy storage units and charging module 120 can be set based on actual conditions, and reasonable parameter configuration is sufficient to meet charging requirements. When there are multiple energy storage units, the power of the energy storage module is the sum of the power of the multiple energy storage units.

[0164] Exemplarily, the maximum charging output power of the charging module 120 is greater than or equal to 350 kilowatts, that is, the maximum charging output power of the charging device 100 is greater than or equal to 350 kilowatts. For example, by selecting an appropriate number of energy storage units, the maximum charging output power of the charging module 120 can reach 350 kilowatts, 360 kilowatts, 500 kilowatts, 800 kilowatts, and 900 kilowatts, etc. It should be noted that the charging output power here refers to the maximum charging output power. During actual charging, it can be backward compatible. For example, when the maximum charging output power is 360 kilowatts, it means that the charging device 100 can output a charging output power of 0 to 360 kilowatts to meet different charging needs.

[0165] It is understandable that the maximum charging output power of the charging module 120 satisfies a certain multiple relationship with the rated charging output power, for example, 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 kilowatts, that is, the rated charging output power of the charging device 100 is greater than or equal to 290 kilowatts.

[0166] In practical applications, the maximum charging output power of the charging module 120 may be limited, the rated charging output power may be limited, or both may be limited at the same time.

[0167] In the above embodiments, by configuring a modular energy storage unit inside the charging device, or arranging a modular energy storage unit and a modular charging unit outside the charging device, that is, arranging an energy storage module and a charging module outside the charging device, the energy storage unit and the charging unit can be freely increased or decreased. When high-power charging is required, the free and rapid access of the energy storage unit can not only achieve high-power charging, such as fast charging / super charging, but also eliminate the need for additional transformers or transformer expansion, thereby reducing transformer costs.

[0168] In some embodiments, reference Figure 2 The charging device 100 further includes an input module 130 , which is adapted to provide charging energy to each energy storage unit.

[0169] In one example, the input module 130 may be an ACDC conversion unit.

[0170] Taking the input module 130 as an ACDC 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 that is sensitive to infrastructure construction costs, the charging device relies on the cooperation between the input module 130 and the energy storage module 110, and uses the input module 130 to adjust the power supply parameters of the energy storage module 110, thereby achieving a fast charging function without relying on complex external power supply upgrades, thereby enhancing the applicability and flexibility of the charging device in various scenarios.

[0171] In this way, the grid can charge the energy storage unit through the input module 130 .

[0172] In some embodiments, the maximum output power of the input module 130 is less than or equal to 150 kilowatts, and / or the rated output power of the input module 130 is less than or equal to 125 kilowatts.

[0173] Specifically, the input module 130 is mainly used to charge the various energy storage units in the energy storage module 110, and is low-power charging during charging. Exemplarily, the maximum output power of the input module 130 is less than or equal to 150 kilowatts, for example, the maximum output power is 150 kilowatts, 100 kilowatts, and 85 kilowatts, etc. It should be noted that the output power here refers to the maximum output power. During actual charging, it can be backward compatible. For example, when the maximum output power is 150 kilowatts, it means that an output power of 0 to 150 kilowatts can be used to charge the various energy storage units in the energy storage module 110.

[0174] In this example, the input module 130 has a low power output, while the charging module 120 has a high power output. Therefore, the entire charging device 100 can achieve high power output with 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, the maximum output power of the input module 130 will also be limited by the capacity of the transformer. For example, the maximum output power is 150 kilowatts. At this time, the energy storage units in the energy storage module 110 are charged with low power. However, when the energy storage module 110 discharges 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 kilowatts. In this way, high power output is achieved with low power input, allowing the charging device to meet high-power charging needs without adding an additional transformer or expanding the transformer capacity. Those skilled in the art will understand that the power grid generally refers to a system that can provide electricity. As an example, the power grid can be a municipal power source.

[0175] It is understandable that the maximum output power of the input module 130 satisfies a certain multiple relationship with the rated output power, such as a multiple relationship of 1.1 to 1.2, so the rated output power of the input module 130 can be less than or equal to 125 kilowatts.

[0176] In practical applications, the maximum output power of the input module 130 may be limited, the rated output power may be limited, or both may be limited at the same time.

[0177] In the above-described embodiment, by configuring a modular energy storage unit within the charging device 100, the maximum output power and / or rated power of the input module 130 is limited to the above-described range, allowing the charging device 100 to flexibly connect to the power grid. Specifically, since the output power of most public power grids or commercial power interfaces is limited, the power setting of the input module 130 enables smooth access to charging energy from conventional power sources without modifying existing power supply lines. This improves the accessibility of the charging device 100 in various power usage scenarios and facilitates its installation. Furthermore, the charging device 100 can achieve high-power charging with low power input, allowing the charging device 100 to meet high-power charging needs without adding an additional transformer or expanding the transformer capacity. During peak hours, when multiple electrical devices are operating simultaneously, the energy storage module provides power to the multiple devices, while the input module 130 stably charges the energy storage unit at a lower power level. This effectively reduces the impact of the charging device 100 on the power grid during charging, helping to maintain grid stability.

[0178] 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.

[0179] 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, thereby achieving high power output with low power input. For example, 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 that the maximum output power of the input module 130 is 40 kilowatts, the maximum charging output power of the charging module 120 is greater than or equal to 500 kilowatts.

[0180] At the same time, 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 and 6, etc. For example, 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 that the maximum output power of the input module 130 is 150 kilowatts, then the maximum charging output power of the charging module 120 is less than or equal to 900 kilowatts.

[0181] It should be noted that when setting the above-mentioned ratios, 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, and so on. The specific setting is selected according to actual needs.

[0182] In this way, by limiting 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 achieve high cost performance and good performance while realizing low power input and high power output.

[0183] It can be understood that the maximum charging output power of the charging module 120 and the rated charging output power satisfy a certain multiple relationship, such as a multiple relationship of 1.1 to 1.2. At the same time, the maximum output power of the input module 130 and the rated output power satisfy a certain multiple relationship, 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.

[0184] In actual 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 limited, 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 limited, or both can be limited at the same time.

[0185] In the above embodiments, 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, current surges and overheating caused by instantaneous excessive power input to the charging module 120 can be reduced. On the other hand, the input module 130 can charge the energy storage module 110 at a low power, and the energy storage module then outputs a controllable high power to the charging module 120, thereby achieving low power input to the energy storage module 110 and high power output from the charging module 120. Furthermore, the energy storage module 110 can flexibly adjust its output power based on its own stored power and the power requirements of the electrical devices, allowing the charging device 100 to rationally distribute electrical energy, reduce unnecessary energy consumption, improve the cost-effectiveness of the charging device 100, and ensure stable operation of the charging device 100 when low power input and high power output are present.

[0186] 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 n1 ranges from 1 to 4.

[0187] Specifically, the rated energy of a battery subunit refers to the energy capacity specified during the design of the battery subunit. It 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 stipulating 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 are matched, and the input module 130 does not charge the battery subunit too slowly, affecting the use of the energy storage unit. At the same time, stipulating 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. This further realizes a small-volume energy storage unit, achieves low power input and high power output, and improves user experience.

[0188] 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.

[0189] That is, the rated energy of the battery subunit is ≥ the rated charging output power of the charging module 120 / (n2*n3)*100%, where n2 can be 94%, 96%, 98.5%, and 99%, and n3 can be 4, 5, 5.5, and 6. This configuration ensures charging performance while also taking into account the reliability of the charging device 100. When the rated energy of the battery subunit is compatible with the rated charging output power of the charging module 120, the battery subunit can stably provide energy to the charging module 120 during the charging process, reducing the risk of unstable or interrupted charging power due to insufficient energy supply. Taking n2 as 94% and n3 as 6 as an example, the larger denominator requires the battery subunit to have a relatively high rated energy to match the power of the charging module 120. This allows the charging device 100 to operate continuously and stably during long-term, high-power charging, reduces the probability of failure, and reduces maintenance costs, thereby extending the service life of the charging device 100 and improving its cost-effectiveness.

[0190] In some embodiments, each energy storage unit 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 380 watt-hours / liter.

[0191] That is to say, the ratio of the rated energy to the rated power of the battery subunit is not greater than 1:3. For example, when the rated power of the battery subunit is 350 kilowatts, the rated energy of the battery subunit is 58 kilowatts. Such a setting can improve the cost-effectiveness of the entire charging device.

[0192] The volumetric energy density of the battery subunit is greater than or equal to 380 Wh / L, and can be, for example, 380 Wh / L, 400 Wh / L, 600 Wh / L, or 900 Wh / L. It will be appreciated that the higher the energy density of the battery subunit, the smaller its volume, thereby saving space and reducing construction costs while still providing high power output.

[0193] When the charging device 100 outputs high power (the maximum charging output power of the charging module is 350 kW or greater), 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 380 watt-hours / liter. This ensures that the rated energy of the battery subunit matches the rated power, reduces grid fluctuations caused by the need for grid power supply due to insufficient rated energy of the battery subunit due to high power output, and is beneficial to improving the reliability and stability of the charging device 100. When outputting high power, the charging device 100 can operate continuously and stably, reducing the probability of failure and lowering maintenance costs, thereby extending the service life of the charging device 100 and improving cost-effectiveness.

[0194] 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 4 times the rate, for example, the maximum discharge rate is greater than or equal to 5 times the rate, 6 times the rate, 7 times the rate, or 8 times the rate, etc. In this way, high power output can be provided.

[0195] It should be noted that the above parameters can be superimposed. For example, when the maximum charging output power of the charging module 120 is greater than or equal to 350 kilowatts, the maximum output power of the battery subunit is greater than or equal to 350 kilowatts, the rated power of the battery subunit is greater than or equal to 350 kilowatts, 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 4 times, and the maximum output power of the input module 130 can be less than or equal to 150 kilowatts.

[0196] It should be noted that the aforementioned parameters related to battery subunits, in some cases, also apply to energy storage units and / or energy storage modules. That is, in some cases, the aforementioned parameters are applicable to energy storage units, energy storage modules, and battery subunits. For example, when an energy storage unit includes only battery subunits, the relevant parameters of the battery subunits are also the relevant parameters of the energy storage unit. Furthermore, when the energy storage module 110 includes only one energy storage unit, the relevant parameters of the battery subunits are also the relevant parameters of the energy storage module 110; and so on.

[0197] It should be noted that the energy storage unit may include one or more battery subunits, and multiple battery subunits may be connected in series, in parallel, or in series and parallel. Each battery subunit may be a single cell, or it may be formed by multiple single cells connected in series, in parallel, or in series and parallel. For example, the single cells may include 10 to 100, and 2 to 6 battery subunits may be obtained by combining the single cells, and the 2 to 6 battery subunits are connected in series and / or in parallel. The energy storage unit can reach a capacity of 80 kWh to 150 kWh through 2 to 6 battery subunits. For example, 80 kWh can be achieved by combining 2 single cells; for another example, 150 kWh can be achieved by combining 100 single cells; for another example, 90 kWh can be achieved by combining 80 single cells; and so on.

[0198] In the above embodiment, by limiting the proportional relationship between 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, the entire charging device can have a high cost-effectiveness.

[0199] In some embodiments, one or more energy storage units are connected in series and / or in parallel between the second positive power terminal and the second negative power terminal of the energy storage module 110 via the first positive power terminal and the first negative power terminal to provide a first direct current.

[0200] 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 through the energy storage unit.

[0201] When there are multiple energy storage units, the multiple energy storage units can be connected in series, in parallel, or in series and in parallel. Figure 1 , 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 terminal and first negative power supply terminal; for example, referring to Figure 3, 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 via their own first positive power supply terminal and first negative power supply terminal. For another example, multiple energy storage units can be connected in series first and then in parallel, or first 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 DC power is provided by connecting multiple energy storage units in series, in parallel, or in series and parallel. The specific connection method to be used can be selected based on actual conditions.

[0202] In the above embodiments, multiple energy storage units can be connected in series, in parallel, or in series-parallel, which allows for free access of energy storage units to meet different charging power requirements.

[0203] In some embodiments, reference 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 power of the battery subunit.

[0204] For example, refer to Figure 4a , the energy storage unit A1 includes battery subunits BAT1, ..., energy storage unit A n-1 Including battery subunit BAT n-1 , Energy storage unit A n Including battery subunit BAT n Each energy storage unit provides the second direct current based on the power of the battery subunit, and the plurality of energy storage units provide the first direct current to the charging module 120 by being connected in series and / or in parallel.

[0205] In some embodiments, reference Figure 4b 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 the energy storage unit, respectively, and is configured to convert the electrical energy of the battery subunit into a second direct current; wherein, when 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.

[0206] 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.

[0207] When there are multiple energy storage units, a first power conversion subunit may be provided in each of the multiple energy storage units, or a first power conversion subunit may be provided in some of the multiple energy storage units. Figure 4bIn the embodiment, the energy storage unit A1 includes a battery subunit BAT1 and a first power conversion subunit B1. The first power conversion subunit B1 is connected to the first positive power supply terminal and the first negative power supply terminal of the battery subunit BAT1 and the energy storage unit A1 respectively. The first power conversion subunit B1 converts the electric energy of the battery subunit BAT1 into a second direct current. n-1 Including battery subunit BAT n-1 and the first power conversion subunit B n-1 , the first power conversion sub-unit Bn-1 is respectively connected to the battery sub-unit BAT n-1 and energy storage unit A n-1 The first positive power supply terminal and the first negative power supply terminal are connected to each other through the first power conversion subunit B n-1 The battery subunit BAT n-1 The electrical energy is converted into the second direct current; the energy storage unit A n Including battery subunit BAT n , battery subunit BAT n Directly with energy storage unit A n The first positive power supply terminal and the first negative power supply terminal are connected to provide a second direct current.

[0208] In some embodiments, when the battery subunit is discharging, 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 no 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 no greater than 1:4.

[0209] In the above embodiment, some or all of the multiple energy storage units can be provided with a first power conversion sub-unit, and the electric energy of the battery sub-unit is converted by the first power conversion sub-unit to provide a second direct current. This can improve the flexibility of charging. At the same time, by partially setting up the first power conversion sub-unit, the cost can be reduced while meeting the charging needs. Moreover, this method can realize the access with and without the first power conversion sub-unit, and has high applicability.

[0210] In some embodiments, reference Figure 4cAt least some of the one or more energy storage units further include a first switch subunit, which is respectively 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, 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 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 the second direct current.

[0211] Specifically, when there is only one energy storage unit, the energy storage unit also includes a first switch subunit. When the first switch subunit is turned on, 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 abnormal circumstances, such as abnormalities in the battery subunit or the charging module 120, the first switch subunit is disconnected 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 power requirements, the first switch subunit is disconnected to stop the battery subunit from providing the second direct current.

[0212] When there are multiple energy storage units, a first switch sub-unit may be provided in each of the multiple energy storage units, or a first switch sub-unit may be provided in some of the multiple energy storage units. Figure 4c In the embodiment, the energy storage unit A1 includes a battery subunit BAT1 and a first switch subunit C1. The first switch subunit C1 is connected to the first positive power supply terminal and the first negative power supply terminal of the battery subunit BAT1 and the energy storage unit A1, respectively. The first switch subunit C1 controls the on-off of the battery subunit BAT1 and the first positive power supply terminal and the first negative power supply terminal of the energy storage unit A1 to selectively provide a second direct current. n-1 Including battery subunit BAT n-1 and the first switch subunit C n-1 , the first switch subunit C n-1 Respectively with the battery subunit BAT n-1 and energy storage unit A n-1 The first positive power supply terminal and the first negative power supply terminal are connected to each other through the first switch subunit C n-1 Control battery subunit BAT n-1 With energy storage unit A n-1 The first positive power supply terminal and the first negative power supply terminal are turned on and off to selectively provide a second direct current; the energy storage unit A n Including battery subunit BAT n , battery subunit BAT n Directly with energy storage unit A nThe first positive power supply terminal and the first negative power supply terminal are connected to provide a second direct current.

[0213] In the above embodiment, some or all of the multiple energy storage units can be provided with a first switch subunit, which selectively controls the battery subunit to provide the second DC power through the first switch subunit, thereby improving charging flexibility and protection in abnormal situations.

[0214] In some embodiments, reference Figure 4d 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 being 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 being 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 where 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.

[0215] Specifically, when there is one energy storage unit, the energy storage unit also includes a first power conversion subunit and a first switch subunit. When the first switch subunit is turned on, the first power conversion subunit converts the electrical energy of the battery subunit into a second direct current; in abnormal circumstances, such as abnormalities in the battery subunit or the charging module 120, the first switch subunit is disconnected and the first power conversion subunit stops working to reduce 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 power requirements, the first switch subunit is disconnected and the first power conversion subunit stops working to stop the battery subunit from providing the second direct current.

[0216] When there are multiple energy storage units, a first switch subunit and a first power conversion subunit may be provided in each of the multiple energy storage units, or a first switch subunit and a first power conversion subunit may be provided in some of the multiple energy storage units. Figure 4d In the embodiment, 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 electric energy of the battery subunit BAT1 into a second direct current. n-1 Including battery subunit BAT n-1 , first switch subunit C n-1 and the first power conversion subunit Bn-1 , the first switch subunit C n-1 and the first power conversion subunit B n-1 Connected in series to the battery subunit BAT n-1 and energy storage unit A n-1 Between the first positive power supply terminal and the first negative power supply terminal, in the first switch subunit C n-1 When the first power conversion subunit B is turned on, n-1 The battery subunit BAT n-1 The electrical energy is converted into the second direct current; the energy storage unit A n Including battery subunit BAT n , battery subunit BAT n Directly with energy storage unit A n The first positive power supply terminal and the first negative power supply terminal are connected to provide a second direct current.

[0217] It should be noted that, in some embodiments, a portion of the energy storage unit may include the first switch sub-unit, and another portion may include the first power conversion sub-unit, which is not specifically limited here.

[0218] In the above embodiment, some or all of the multiple energy storage units may be provided with a first switch sub-unit and a first power conversion sub-unit, thereby improving charging flexibility and protection capability in abnormal situations.

[0219] In some embodiments, the first power conversion subunit is a bidirectional DCDC subunit, which is used to charge and discharge the battery subunit. The bidirectional DCDC subunit includes but is not limited to a BUCK-BOOST circuit, etc., which is not specifically limited here.

[0220] In some embodiments, reference Figure 5a The input module 130 includes an input interface (X, Y), which 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 to each energy storage unit based on the third direct current provided by the first external power supply 210.

[0221] Specifically, the first external power source 210 is configured to generate a third direct current (DC) and transmit the third DC power to the energy storage module 110 via the input interface to charge the energy storage units in the energy storage module 110. Exemplarily, the first external power source 210 may include a first transformer and a first AC / DC conversion module. The primary winding of the first transformer is connected to an AC power grid to convert the second AC power provided by the AC power grid into the first AC power. The first AC / DC conversion module is connected to the secondary winding of the first transformer and the input interface, respectively, to convert the first AC power into a third DC power and transmit the third DC power to the energy storage module 110 via the input interface.

[0222] The first AC / DC conversion module can be a unidirectional ACDC subunit or a bidirectional ACDC subunit. When the first AC / DC conversion module is a bidirectional ACDC subunit, it can not only charge the energy storage module 110 but also feed the power of the energy storage module 110 into the AC power grid. The specific circuit structure of the unidirectional ACDC subunit or the bidirectional ACDC subunit is not limited here.

[0223] 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 source 210 .

[0224] In the above embodiment, when the external power supply provides direct current, the battery subunit can be charged through the input interface.

[0225] In some embodiments, reference Figure 5b The input module 130 includes a second power conversion subunit 131, which 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 to each energy storage unit based on the first alternating current provided by the second external power supply 220.

[0226] Specifically, the second external power source 220 is used to generate a first alternating current (AC) and provide it to the second power conversion subunit 131 in the input module 130. The second power conversion subunit 131 is used to charge the various battery subunits in the energy storage module 110. Exemplarily, the second external power source 220 may include a first transformer, the primary winding of the first transformer being connected to the AC grid, the second power conversion subunit 131 being connected to the secondary winding of the first transformer and the energy storage module 110, respectively. The first transformer converts the second AC power provided by the AC grid into a first AC power, which is provided to the second power conversion subunit 131. The second power conversion subunit 131 converts the first AC power into a third DC power to charge the energy storage module 110.

[0227] 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 power of the energy storage module 110 to the AC power grid. The specific circuit structure of the unidirectional ACDC subunit or the bidirectional ACDC subunit is not limited here.

[0228] 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 sub-unit 131 .

[0229] In the above embodiment, when the external power source provides alternating current, the battery subunit can be charged through the second power conversion subunit.

[0230] 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 , and the charging gun 122 is connected to the energy storage module 110 through the charging module conversion unit.

[0231] The number of charging guns 122 can be one, two, or more than three. For example, there are two charging guns 122, each with a maximum charging output power or rated output power of 500 kW. They can simultaneously charge the same electrical device, which can be an electric vehicle. Each charging gun 122 can also charge different electrical devices independently.

[0232] When there are multiple charging guns 122, the multiple charging guns 122 can be connected to the energy storage module 110 through the same charging module conversion unit, or each charging gun 122 can be connected to the energy storage module 110 through a separate 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, or a bipolar unidirectional DCDC conversion unit or a bipolar bidirectional DCDC conversion unit.

[0233] The charging module conversion unit flexibly adjusts parameters such as voltage and current based on the DC power output of the energy storage module 110 and the needs of the device connected to the charging gun 122 (such as an electric vehicle), achieving 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. This improves the efficiency and service capabilities of the charging device 100, meets the requirements of large-scale charging demand scenarios, effectively alleviates charging queues, and enhances the user experience.

[0234] In some embodiments, reference Figure 6aThe 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.

[0235] Specifically, when charging the device to be charged, one or more energy storage units provide the second direct current, so that the energy storage module 110 provides the first direct current, and the first direct current is converted into the fourth direct current by the third power conversion sub-unit 121 and provided to the charging gun 122, which is provided by the charging gun 122 to the device to be charged to charge the device to be charged.

[0236] In this example, the third power conversion subunit 121 is bipolar, that is, it has a positive input terminal and a negative input terminal. In this case, 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. 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. This is suitable for application scenarios where the third power conversion subunit 121 has a bipolarity.

[0237] 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, it can not only charge the device to be charged, but also feed the power of the device to be charged to the energy storage module 110, and can also feed the power to the AC power grid of the aforementioned example through the input module 130, ultimately realizing the free conversion of power between the grid, charging, and storage.

[0238] In some embodiments, reference 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, 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. 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.

[0239] Specifically, when charging the device to be charged, one or more energy storage units provide the second direct current, so that the energy storage module 110 provides the first direct current, and the first direct current is converted into the fourth direct current by the fourth power conversion sub-unit 123 and provided to the charging gun 122, which is provided by the charging gun 122 to the device to be charged to charge the device to be charged.

[0240] In this example, the fourth power conversion subunit 123 is unipolar, that is, it has only a positive input terminal. In this case, 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, and 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. This is suitable for application scenarios where the fourth power conversion subunit 123 has a unipolarity and is low-cost.

[0241] The fourth power conversion subunit 123 can be a unipolar unidirectional DCDC subunit or a unipolar bidirectional DCDC subunit. When the fourth power conversion subunit 123 is a unipolar bidirectional DCDC subunit, it can not only charge the device to be charged, but also feed the power of the device to be charged to the energy storage module 110, and can also feed the power to the AC power grid of the aforementioned example through the input module 130, ultimately realizing the free conversion of electric energy between the grid, charging, and storage.

[0242] In the above embodiment, by sharing or not sharing the negative input terminal of the charging gun, it can be applied to different power supply scenarios, thereby increasing the range of choices when selecting the circuit structure.

[0243] In some embodiments, reference Figure 7 The energy storage module 110 further includes a selection unit 111, which 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.

[0244] Specifically, when 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 the first direct current; or select all energy storage units A1, ..., energy storage units A n-1 and energy storage unit A n The first DC power supply is 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 DC power. Then, the charging module 120 performs charging output based on the first DC power.

[0245] In the above embodiment, the selection unit selectively controls the output of the energy storage unit, thereby improving the flexibility of charging and meeting different charging requirements.

[0246] In some embodiments, reference Figure 8 The second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 each include one, the selection unit 111 includes multiple 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 terminal of one or more energy storage units is respectively connected to the second negative power supply terminal of the energy storage module 110, 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 110 when it is turned on.

[0247] Specifically, the selection unit 111 includes a second switch subunit K1, ..., a second switch subunit Kn-1, and a second switch subunit Kn, wherein the second switch subunit 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 subunit Kn-1 is connected in series between the energy storage unit A1 and the second positive power supply terminal of the energy storage module 110. n-1 The second switch subunit Kn is connected in series between the first positive power supply terminal of the energy storage module A and the second positive power supply terminal of the energy storage module 110. n The first positive power supply terminal of the energy storage module 110 is connected to 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 the second DC power, thereby enabling the energy storage module 110 to provide the first DC power. At this time, the charging module 120 converts the first DC power into a fourth DC power to charge the device to be charged.

[0248] In the above embodiment, by providing a second positive power supply terminal 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 demand.

[0249] In some embodiments, reference 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.

[0250] It should be noted that regarding 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 aforementioned description of the third power conversion subunit 121, and the details will not be repeated here.

[0251] In some embodiments, reference 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, 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. 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.

[0252] It should be noted that regarding 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 aforementioned description of the fourth power conversion subunit 123, and the details will not be repeated here.

[0253] In some embodiments, reference Figure 10 The energy storage module 110 includes multiple second positive power supply terminals, the energy storage module 110 includes one second negative power supply terminal, the selection unit 111 includes multiple 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 and the corresponding second positive power supply terminal of the corresponding energy storage unit, the first negative power supply terminal of one or more energy storage units is respectively connected to the second negative power supply terminal of the energy storage module 110, 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.

[0254] Specifically, the selection unit 111 includes a second switch subunit K1, ..., a second switch subunit Kn-1, and a second switch subunit Kn, wherein the second switch subunit K1 is connected in series between the first positive power supply terminal of the energy storage unit A1 and a second positive power supply terminal of the energy storage module 110, ..., the second switch subunit Kn-1 is connected in series between the energy storage unit A1 and a second positive power supply terminal of the energy storage module 110. n-1 The second switch subunit Kn is connected in series between the first positive power supply terminal of the energy storage module A and the other second positive power supply terminal of the energy storage module 110. nThe first positive power supply terminal of the energy storage module 110 is connected to 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 the second DC power, thereby causing the energy storage module 110 to provide the first DC power. At this time, the charging module 120 converts the first DC power into a fourth DC power to charge the device to be charged. It should be noted that the first DC power here includes multiple second DC power sources, and the charging module 120 can selectively convert one or more second DC power sources into the fourth DC power source.

[0255] In the above embodiment, by providing a plurality of second positive power supply terminals and selectively controlling the energy storage unit to provide the second direct current through the selection unit, the flexibility of charging can be improved to meet the charging demand.

[0256] In some embodiments, reference 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 a fourth direct current for charging output through the charging gun.

[0257] Specifically, the plurality of seventh power conversion sub-units are respectively a seventh power conversion sub-unit D1, ..., a seventh power conversion sub-unit D n-1 and the seventh power conversion subunit D n , wherein the positive input terminal of the seventh power conversion subunit D1 is connected to a second positive power supply terminal, ..., the seventh power conversion subunit D n-1 The positive input terminal of the seventh power conversion sub-unit D is connected to another second positive power supply terminal. n The positive input terminal of the seventh power conversion sub-unit D1 is connected to another second positive power supply terminal, and the seventh power conversion sub-unit D1, ..., the seventh power conversion sub-unit D n-1 and the seventh power conversion subunit D n The negative input terminals of the seventh power conversion subunits D1, ..., the seventh power conversion subunits D n-1 and the seventh power conversion subunit D n The positive output terminal and the negative output terminal of the charging gun 122 are respectively connected to the positive input terminal and the negative input terminal of the charging gun 122.

[0258] In this example, each seventh power conversion sub-unit may convert the second direct current of the corresponding energy storage unit into the fifth direct current, and finally the plurality of seventh power conversion sub-units output the fourth direct current.

[0259] 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 power of the device to be charged to the energy storage module 110, and can also feed the power to the AC power grid of the aforementioned example through the input module 130, ultimately realizing the free conversion of electric energy between the grid, charging, and storage.

[0260] In some embodiments, reference 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, 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. The multiple eighth power conversion subunits are configured to convert the first direct current into a fourth direct current for charging output through the charging gun 122.

[0261] Specifically, the plurality of eighth power conversion sub-units are respectively an eighth power conversion sub-unit E1, ..., an eighth power conversion sub-unit E2, ..., an eighth power conversion sub-unit E3, ..., an eighth power conversion sub-unit E4, ..., an eighth power conversion sub-unit E5, ..., an eighth power conversion sub-unit E6, ..., an eighth power conversion sub-unit E7, ..., an eighth power conversion sub-unit E8, ..., an eighth power conversion sub-unit E9, ..., an eighth power conversion sub n-1 and the eighth power conversion subunit E n , wherein the positive input terminal of the eighth power conversion sub-unit E1 is connected to a second positive power supply terminal, ..., the eighth power conversion sub-unit E n-1 The positive input terminal of the eighth power conversion sub-unit E is connected to another second positive power supply terminal. n The positive input terminal of the eighth power conversion sub-unit E1 is connected to another second positive power supply terminal, and the eighth power conversion sub-unit E1, ..., the eighth power conversion sub-unit E n-1 and the eighth power conversion subunit E n The positive output terminals of the charging gun 122 are 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 .

[0262] In this example, each eighth power conversion sub-unit may convert the second direct current of the corresponding energy storage unit into the fifth direct current, and finally the plurality of eighth power conversion sub-units output the fourth direct current.

[0263] The eighth power conversion subunit can be a unipolar unidirectional 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 electric energy of the device to be charged to the energy storage module 110, and can also feed the electric energy to the AC power grid of the aforementioned example through the input module 130, ultimately realizing the free conversion of electric energy between the grid, charging, and storage.

[0264] In the above embodiment, by sharing or not sharing the negative input terminal of the charging gun, it can be applied to different power supply scenarios, thereby increasing the range of choices when selecting the circuit structure.

[0265] In some embodiments, reference Figure 12a The input module 130 includes a ninth power conversion subunit 132 , which is connected to one or more energy storage units and is configured to provide charging energy to each energy storage unit based on the first alternating current provided by the second external power source 220 .

[0266] Specifically, the second external power source 220 is used to generate a first alternating current (AC) and provide it to the ninth power conversion subunit 132 in the input module 130. The ninth power conversion subunit 132 is used to charge the battery subunits in the energy storage module 110. Exemplarily, the second external power source 220 may include a second transformer, wherein the primary winding of the second transformer is connected to the AC grid, and the secondary winding of the second transformer is connected to the ninth power conversion subunit 132. The second transformer converts the second AC power provided by the AC grid into a first AC power, which is provided to the ninth power conversion subunit 132. The ninth power conversion subunit 132 converts the first AC power into a third DC power to charge the energy storage module 110.

[0267] Exemplarily, the second external power source 220 is a three-phase AC power source, and the ninth power conversion subunit 132 is a unidirectional three-phase ACDC subunit or a bidirectional three-phase ACDC subunit. In this case, 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 energy storage module 110 be charged, but the electric energy of the energy storage module 110 can also be fed to the AC power grid. In this way, in the three-phase AC power, a single phase is implemented by an energy storage unit, and the three energy storage units can realize the function of three-phase AC power, for example, three-phase industrial frequency AC power with a phase difference of 120°. The specific circuit structure of the unidirectional three-phase ACDC subunit or the bidirectional three-phase ACDC subunit is not limited here.

[0268] 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 ninth power conversion sub-unit 132 .

[0269] In the above embodiment, when the external power source provides alternating current, the battery subunit can be charged through the ninth power conversion subunit.

[0270] In some embodiments, reference Figure 12bThe input module 130 includes a plurality of tenth power conversion subunits, each of which is connected to an energy storage unit, and the plurality of tenth power conversion subunits are configured to provide charging energy to each energy storage unit based on the first alternating current provided by the second external power source 220.

[0271] Specifically, the plurality of tenth power conversion sub-units are respectively a tenth power conversion sub-unit F1, ..., a tenth power conversion sub-unit F n-1 , tenth power conversion subunit F n , wherein the tenth power conversion subunit F1 is connected to the second external power source 220 and the energy storage unit A1 respectively, ..., the tenth power conversion subunit F n-1 Respectively connected to the second external power supply 220 and the energy storage unit A n-1 Connected, the tenth power conversion subunit F n Respectively connected to the second external power supply 220 and the energy storage unit A n Each tenth power conversion sub-unit can charge the corresponding energy storage unit based on the first alternating current provided by the second external power source 220 .

[0272] Exemplarily, the second external power source 220 is a three-phase AC power source, and the tenth power conversion subunit includes three, each of which is a unidirectional single-phase ACDC subunit or a bidirectional single-phase ACDC subunit. In this case, each tenth power conversion subunit is connected to one phase of the three-phase AC power source to charge the corresponding energy storage unit. When the tenth power conversion subunit is a bidirectional single-phase 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. When feeding, the three bidirectional single-phase ACDC subunits cooperate with each other to form a three-phase AC power feed to the three-phase AC power grid. In this way, in the three-phase AC power, a single phase is realized by an energy storage unit, and the three energy storage units can realize the function of three-phase AC power. The specific circuit structure of the unidirectional single-phase ACDC subunit or the bidirectional single-phase ACDC subunit is not limited here.

[0273] It should be noted that, in this example, the maximum output power and rated output power of the input module 130 are the sum of the maximum output power and rated output power of the plurality of tenth power conversion sub-units.

[0274] In the above embodiment, when the external power source provides alternating current, the battery sub-unit can be charged through the plurality of tenth power conversion sub-units.

[0275] In some embodiments, reference Figure 13The charging device 100 also includes a wireless communication module 140 , and at least part of the energy storage module 110 , the input module 130 and the charging module 120 are connected to the wireless communication module 140 to exchange information with external devices through the wireless communication module 140 .

[0276] It should be noted that in the above embodiments, a variety of charging device architectures are provided. For example, multiple energy storage units can be connected in series, in parallel, or in series and 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 terminal of the corresponding charging pile can be shared or not shared; a single phase of three-phase AC power is realized by an energy storage unit, and three energy storage units can realize the function of three-phase AC power; the input module can be an AC input or a DC input; and so on.

[0277] In order to enable those skilled in the art to more clearly understand the present application, the present application is described below with reference to specific examples, but this is not intended to limit the present application.

[0278] Example 1, refer to Figure 14 Energy storage module 110 includes multiple energy storage units, each of which includes a battery subunit and a first power conversion subunit. The first power conversion subunit can be a bidirectional DC-DC 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 energy storage module 110. The second positive power supply terminal and the second negative power supply terminal of energy storage module 110 are connected to the DC bus. That is, the multiple energy storage units are connected in series to the DC bus. Charging module 120 includes a third power conversion subunit 121 and a charging plug 122. The third power conversion subunit 121 has a high-voltage positive input terminal and a high-voltage negative input terminal, as well as a high-voltage positive output terminal and a high-voltage negative output terminal. The third power conversion subunit 121 can be a bipolar bidirectional DC-DC subunit. Input module 130 includes a second power conversion subunit 131, which can be a bidirectional AC-DC subunit. Second external power supply 220 includes a first transformer connected to the AC power grid.

[0279] When charging the energy storage module 110, the first transformer converts the second AC power provided by the AC grid into the first AC power, which is then converted into DC power by the bidirectional ACDC subunit and then charged to each battery subunit in the energy storage module 110 through the DC bus.

[0280] When charging the device to be charged, the energy storage unit provides a second DC power based on the power of the battery subunit, and the energy storage module 110 obtains a first DC power based on the second DC power. The first DC power is converted by the high-power bipolar bidirectional DCDC subunit to obtain a fourth DC power, and is charged to the device to be charged through the charging gun 122 to achieve high-power charging, thereby achieving fast charging / super charging of the device to be charged.

[0281] It is understandable that, under the action of the bidirectional ACDC subunit and the bipolar bidirectional DCDC subunit, the electric energy of the device to be charged can also be fed to the energy storage module 110 or the AC power grid, thereby realizing free switching of electric energy between the device to be charged, the energy storage module 110 and the AC power grid.

[0282] Example 2, refer to Figure 15 , this example is compared to Figure 14 The example shown differs in that the fourth power conversion subunit 123 has only a high-voltage positive input and a high-voltage positive output. The high-voltage negative input of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110. That is, the charging gun 122 and the energy storage module 110 share a common negative terminal. This fourth power conversion subunit 123 can be a unipolar, bidirectional DC-DC subunit. To avoid redundancy, the same details are not repeated here.

[0283] Example 3, refer to Figure 16 , this example is compared to Figure 14 The example shown is different in that a plurality of 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, a plurality of energy storage units are connected in parallel to the DC bus.

[0284] Example 4, refer to Figure 17 , this example is compared to Figure 16 The example shown is different in 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 charging gun 122 and the negative pole of the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit.

[0285] Example 5, refer to Figure 18 , this example is compared to Figure 14 The example shown is different in that: some of the energy storage units include battery subunits, and another part of the energy storage units include battery subunits and the first power conversion subunit. For example, energy storage unit A1 includes a battery subunit, and energy storage unit A n Includes battery subunit and bidirectional DCDC subunit A n .

[0286] Example 6, refer to Figure 19 , this example is compared to Figure 18 The example shown is different in 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 charging gun 122 and the negative pole of the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit.

[0287] Example 7, refer to Figure 20 , this example is compared to Figure 16 The example shown is different in that each energy storage unit includes a battery subunit and a first switch subunit. The first switch subunit can be a protection switch to protect the energy storage unit in abnormal situations.

[0288] In Examples 1 through 7 above, the energy storage module 110 and the charging module 120 are both connected to a DC bus, meaning the charging device 100 utilizes a DC bus design. When multiple energy storage modules 110 and charging modules 120 are provided, the multiple charging devices 100 share a common DC bus. When the charging device 100 utilizes a DC bus design, if the maximum charging output power of the charging device 100 is greater than or equal to 350 kilowatts, the maximum output power of the battery subunit is greater than or equal to 350 kilowatts, the rated power of the battery subunit is greater than or equal to 350 kilowatts, the rated energy of the battery subunit is greater than or equal to 58 kilowatts, 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 kilowatts, and the rated power of the first power conversion subunit is greater than or equal to 310 kilowatts. The maximum output power of the input module 130 is less than or equal to 150 kilowatts, 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 no greater than 1:4.

[0289] Example 8, refer 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. 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 and a high-voltage negative input terminal, as well as a high-voltage positive output terminal and a high-voltage negative output terminal. 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.

[0290] When charging the energy storage module 110, the second transformer converts the second AC power provided by the AC grid into the first AC power, which is converted into DC power by the bidirectional single-phase ACDC sub-unit before charging the corresponding battery sub-unit. Each bidirectional single-phase ACDC sub-unit is connected to a single-phase 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 grid, the three bidirectional single-phase ACDC sub-units can cooperate with each other to generate three-phase AC power with a phase difference of 120°, so that the output of three-phase AC power can be achieved through the three energy storage units.

[0291] When charging a device to be charged, the energy storage unit provides a second DC power based on the power of the battery subunit. The energy storage module 110 selectively outputs the second DC power to obtain the first DC power through the selection unit 111. The first DC power is converted by the high-power bipolar bidirectional DC-DC subunit to obtain the fourth DC power, which is then charged to the device to be charged through the charging gun 122 to achieve high-power charging and thus fast charging / supercharging of the device to be charged. In some examples, the second switch subunits K1, K2, and K3 can be closed separately and sequentially in a time-sharing manner to maintain the same power in the three energy storage units.

[0292] It is understandable that, under the action of the bidirectional single-phase ACDC subunit and the bipolar bidirectional DCDC subunit, the electric energy of the device to be charged can also be fed to the energy storage module 110 or the AC power grid, thereby realizing free switching of electric energy between the device to be charged, the energy storage module 110 and the AC power grid.

[0293] Example 9, refer to Figure 22 , this example is compared to Figure 21 The example shown is different in that the sixth power conversion subunit 125 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 pole of the charging gun 122 and the energy storage module 110 is shared. The sixth power conversion subunit 125 can be a unipolar bidirectional DCDC subunit.

[0294] In Examples 8 and 9 above, the energy storage module 110 and the charging module 120 are both connected to the AC bus, meaning the charging device 100 uses an AC bus design. When multiple energy storage modules 110 and charging modules 120 are provided, the multiple charging devices 100 share the AC bus.

[0295] In Examples 1 through 9 above, the charging device 100 can communicate with external devices, including but not limited to cloud service / monitoring platforms, via wireless communication module 140 to achieve 4G / 5G communication. The cloud service / monitoring platform selects appropriate peak / valley time periods based on the peak / valley time periods in the region where the charging device 100 is located, and transmits this information to the charging device 100, thereby enabling the charging device 100 to implement peak load shifting. For example, during peak hours of the AC grid, the AC grid does not charge the energy storage module 110, while during off-peak hours, the AC grid slowly charges the energy storage module 110.

[0296] It should be noted that the above examples 1 to 9 are merely exemplary descriptions. Based on the inventive concept of this application, through reasonable setting of the above-mentioned architecture, they should all be within the scope of protection of this application.

[0297] In order to further illustrate the implementation method of the solution in which the rated charging output power of the charging module of the present application is greater than or equal to 290 kilowatts, the battery subunit is described in detail below.

[0298] In the present application, each energy storage unit may include a battery subunit, and the battery subunit may include one or more single cells. The single cell may include an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate includes a positive electrode current collector and a positive electrode film layer disposed on at least one side of the positive electrode current collector, and the positive electrode film layer includes a positive electrode active material. The negative electrode plate includes a negative electrode current collector and a negative electrode film layer disposed on at least one side of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material. Optionally, the single cell further includes a shell, and the electrode assembly and the electrolyte are contained in the shell. The negative electrode film layer includes at least one film layer, which may be a single film layer or at least two film layers. Optionally, the negative electrode film layer includes at least two film layers. Similarly, the positive electrode film layer may be a single film layer or at least two film layers. During the charge and discharge process of a single battery cell, active ions such as lithium ions are embedded and released back and forth between the positive electrode and the negative electrode, and the electrolyte plays the role of conducting active ions between the positive electrode and the negative electrode.

[0299] The following is a detailed description of the electrolyte, positive electrode sheet, negative electrode sheet and separator:

[0300] [Electrolyte]

[0301] In some embodiments, the electrolyte solution 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.

[0302] By providing the electrolyte with lithium hexafluorophosphate at the above-mentioned concentration, the battery subunit has a higher ionic conductivity, thereby improving the charging rate of the charging device, and also making the battery subunit have higher interface stability and higher thermal stability; lithium hexafluorophosphate has a smaller effect on the severity of thermal runaway, so that the battery subunit has a suitable severity of thermal runaway and a lower risk of thermal diffusion, so that the charging device has higher reliability at a power output of more than 350 kW.

[0303] In some embodiments, the electrolyte further includes an organic solvent, and the organic solvent includes a carbonate solvent.

[0304] 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.

[0305] Further optionally, the mass content of the carbonate solvent in the organic solvent is 10% to 70%, and can be selected from 30% to 50%, 10% to 30%, or 30% to 70%.

[0306] For example, 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 consisting of any two of the above values. The above mass content of the carbonate solvent can further improve the conductivity of the electrolyte at room temperature, which is beneficial to the migration of lithium ions.

[0307] Illustratively, 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%.

[0308] Adding carbonate solvents to the electrolyte can improve various properties of the battery subunits. For example, it can improve the charge and discharge efficiency, cycle performance, low-temperature performance and high-voltage stability of the battery subunits, so that the battery discharge stability can be improved when the battery subunits are output at high power.

[0309] In some embodiments, the electrolyte solution 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.

[0310] Illustratively, 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 consisting of any two of the foregoing values.

[0311] For example, based on the total mass of the electrolyte, the proportion of lithium hexafluorophosphate may be, but is not limited to, 10%-25%.

[0312] By providing the electrolyte with lithium hexafluorophosphate at the above-mentioned concentration, the battery subunit has a higher ionic conductivity, thereby improving the charging rate of the charging device 100, and also making the battery subunit have higher interface stability and higher thermal stability; lithium hexafluorophosphate has a smaller effect on the severity of thermal runaway, so that the battery subunit has an appropriate severity of thermal runaway and a lower risk of thermal diffusion, which makes the charging device have higher reliability at a power output of more than 350 kW.

[0313] In some embodiments, the electrolyte salt further comprises 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-0.5 mol / L.

[0314] The fluorine-containing sulfonyl imide salt may include one or more of lithium bis(fluorosulfonyl)imide LiFSI and lithium bis(trifluoromethanesulfonyl)imide LiTFSI.

[0315] 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.

[0316] For example, the molar concentration of lithium bis(fluorosulfonyl)imide (LiFSI) is 0.4 mol / L to 0.5 mol / L, and the molar concentration of lithium hexafluorophosphate (LiPF) is 0.5 mol / L to 0.4 mol / L. 66 The molar concentration is 0.7 mol / L.

[0317] For example, 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.

[0318] For example, 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.

[0319] 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 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 consisting of any two of the foregoing values.

[0320] In the embodiments of the present application, the types and contents of the inorganic components / lithium salt concentrations in the electrolyte are well known in the art and can be detected using equipment and methods well known in the art. For example, the inorganic components / lithium salt concentrations in the electrolyte can be qualitatively or quantitatively analyzed by ion chromatography analysis methods in accordance with the standard JY / T020-1996 "General Rules for Ion Chromatography Analysis Methods". In the embodiments of the present application, a freshly prepared electrolyte can be taken as a sample, the 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 battery's state of charge is approximately 0% SOC) can be reversely disassembled, and the free electrolyte obtained from the battery can be used as a sample for detection using ion chromatography analysis methods.

[0321] In the embodiments of the present application, the types and contents of organic components in the electrolyte are well known in the art and can be detected using equipment and methods well known in the art. For example, qualitative and quantitative analysis of organic components in the electrolyte can be performed by gas chromatography with reference to GB / T9722-2006, "General Rules for Gas Chromatography of Chemical Reagents." In the embodiments of the present application, a freshly prepared electrolyte can be taken as a sample, free electrolyte from a fresh battery can be taken as a sample, or a battery that has been fully discharged (discharged to the lower cutoff voltage so that the battery's state of charge is approximately 0%) can be disassembled in reverse, and free electrolyte obtained from the battery can be used as a sample for detection using ion chromatography.

[0322] In the embodiment of the present application, after quantitative and qualitative detection of each component in the electrolyte, the components are classified, and chain carboxylic acid ester solvents and carbonate solvents (such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate) are used as components of the organic solvent. The mass content of each component is calculated based on the mass of the organic solvent as 100%.

[0323] Carbonate additives (such as vinylene carbonate, fluoroethylene carbonate), sulfur-containing additives and lithium salt additives are used as additives for the electrolyte. The mass content of each component is calculated based on the mass of the electrolyte being 100%.

[0324] Since the fluorinated sulfonyl imide salt has the characteristics of low viscosity and high ionic conductivity, the electrolyte including the fluorinated sulfonyl imide salt at the above concentration is beneficial to improving the charging rate of the battery subunits, thereby improving the charging rate of the charging device.

[0325] In some embodiments, the organic solvent includes a chain carboxylate solvent, and the mass content A of the chain carboxylate solvent, based on the total mass of the solvent, satisfies: 5%≤A≤75%.

[0326] Among them, the chain carboxylate solvents include compounds with the following structures:

[0327]

[0328] 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.

[0329] The mass content of the linear carboxylate 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%. Illustratively, the mass content of the linear carboxylate solvent is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or a range consisting of any two of the foregoing values.

[0330] 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.

[0331] The above-mentioned chain carboxylic acid ester solvents have high electrical conductivity, which is beneficial to improving the fast charging capability of single battery cells.

[0332] Alternatively, R1 includes a hydrogen atom, a halogen atom, a C1 to C3 alkyl group, or a C1 to C3 haloalkyl group. Further alternatively, R1 includes a hydrogen atom, a halogen atom, a C1 to C2 alkyl group, or a C1 to C2 haloalkyl group.

[0333] Alternatively, R2 comprises a C1 to C3 alkyl group or a C1 to C3 haloalkyl group. Further alternatively, R2 comprises a C1 to C2 alkyl group or a C1 to C2 haloalkyl group.

[0334] 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.

[0335] In each of 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.

[0336] Illustratively, the chain carboxylate solvent includes one or more compounds represented by formula I-1 to formula I-8.

[0337]

[0338] In this technical solution, the solvent includes a carboxylic acid ester solvent, so that the electrolyte can have higher ionic conductivity and relatively low viscosity, which is conducive to further improving the fast charging performance of the charging device, such as fast charging performance and / or supercharging performance.

[0339] In some embodiments, the electrolyte has a conductivity of 13 mS / cm to 20 mS / cm at room temperature, and optionally 15 mS / cm to 20 mS / cm. For example, the electrolyte has a conductivity of 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 consisting of any two of the foregoing values.

[0340] 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 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.

[0341] In the embodiment of the present application, the conductivity of the electrolyte at room temperature, for example, 25° C., is ionic conductivity, which can be tested using equipment and methods known in the art, for example, by referring to the industry standard HG-T 4067-2015.

[0342] In some embodiments, the viscosity of the electrolyte at room temperature is 2.3 mPa·s to 3.5 mPa·s. For example, 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 consisting of any two of the foregoing values.

[0343] 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 higher, 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.

[0344] In the embodiments of the present application, the viscosity of the electrolyte has a well-known meaning in the art and can be detected using equipment and methods well-known in the art, for example, it can be detected according to GB / T10247-2008.

[0345] In some embodiments, the density of the electrolyte at room temperature, e.g., 25° C., is between 1.05 g / mL and 1.35 g / mL. For example, 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 consisting of any two of the foregoing values.

[0346] When the density of the electrolyte is within the above range, the migration rate of lithium ions in the electrolyte is 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.

[0347] In the embodiments of the present application, the density of the electrolyte has a well-known meaning in the art and can be tested using equipment and methods well-known in the art, for example, by referring to GB / T 2013-2010.

[0348] The electrolyte includes an organic solvent and an electrolyte salt. The types of the organic solvent and the electrolyte salt are not particularly limited and can be selected according to actual needs.

[0349] In some embodiments, the electrolyte further contains additives, which may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high temperature performance, additives that improve battery low temperature power performance, etc.

[0350] In some embodiments, the additives include one or more of carbonate additives, sulfur-containing additives, and lithium salt additives, and optionally at least two of these additives. These additives can improve the interfacial film properties on the positive and / or negative electrode sides, thereby enhancing the fast charging performance of the battery cell and improving the cycling performance.

[0351] In some embodiments, the weight content of the additive in the electrolyte is 1% to 10%, optionally 2% to 8%, and further optionally 3.5% to 8%. For example, the weight content of the additive in the electrolyte is 1%, 2%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two of the foregoing values.

[0352] The additives in 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 battery cell and improving the cycle performance.

[0353] Illustratively, the carbonate additive includes one or more of vinylene carbonate VC and fluoroethylene carbonate FEC.

[0354] For example, the sulfur-containing additive includes one or more of vinyl sulfate DTD, vinyl disulfate 2-DTD, butylene sulfite BS, 1,3-propane sultone PS, vinyl sulfite ES, and methylene disulfonate MMDS.

[0355] Optionally, the lithium salt additive includes one or more of lithium difluorophosphate LiPO2F2, lithium difluorooxalatoborate LiDFOB, lithium tetrafluoroborate LiBF4, and lithium bis(oxalatoborate) LiBOB.

[0356] Optionally, the mass content of vinylene carbonate VC in the electrolyte is 0.5% to 9%, optionally 2% to 6%.

[0357] Optionally, the mass content of fluoroethylene carbonate FEC in the electrolyte is 0.1% to 4%, and optionally 0.5% to 3%.

[0358] 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%.

[0359] 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%.

[0360] In some embodiments, a single cell satisfies the following conditions: 2.45g / Ah ≤ d / A ≤ 3.5g / Ah, optionally 2.45g / Ah ≤ d / A ≤ 3.3g / 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. For example, d / A can be 3.5g / Ah, 3.3g / Ah, 3.2g / Ah, 3.0g / Ah, 2.8g / Ah, 2.5g / Ah, 2.45g / Ah, or a range consisting of any two of the foregoing values.

[0361] d / A can reflect the electrolyte's ability to retain liquid. When d / A is within the above range, the electrolyte can better wet the positive and negative electrodes, and can increase the migration rate of lithium ions in the liquid phase, which is beneficial to improving the fast charging capability of the single cell.

[0362] In the embodiment of the present application, the d / A of the single cell can be understood as the liquid retention coefficient, which can be tested using equipment and methods known in the art. For example, it can be described in accordance with GB / T31486-2015 "Electrical Performance Requirements and Test Methods for Power Batteries for Electric Vehicles", taking the battery charging upper limit voltage as 3.65V and the battery discharge cut-off voltage as 2.0V as an example.

[0363] At 25°C, charge a single cell at 0.33C to 3.65V, then charge it at a constant voltage to 0.05C, and then discharge it at a constant current of 0.33C to 2.0V. The discharged capacity A is used as the denominator, and the single cell is weighed as M0. The positive electrode sheet, negative electrode sheet, separator, and electrolyte are then disassembled, with the free electrolyte contained in a bag. All the aforementioned solid components (including but not limited to the positive electrode sheet, negative electrode sheet, separator, and other mechanical parts of the disassembled single cell that contribute to M0) are then baked in a 60°C oven for at least 4 hours. The total weight of all components in the single cell is then weighed as M1, with the weight difference between M0 and M1 as the numerator. The liquid retention coefficient is equal to the weight difference d between M0 and M1 divided by the capacity A.

[0364] [Negative electrode]

[0365] In some embodiments, the resistance value of the negative electrode plate may be, but is not limited to, within the range of 0.001Ω-0.01Ω.

[0366] The resistance of the negative electrode plate may be 0.001Ω to 0.005Ω. For example, the resistance of the negative electrode plate is 0.001Ω, 0.002Ω, 0.003Ω, 0.004Ω, 0.005Ω, 0.006Ω, 0.007Ω, 0.008Ω, 0.009Ω, 0.01Ω, or a range consisting of any two of the above values.

[0367] In other examples, the resistance of the negative electrode plate may be in the range of 1 mΩ-50 mΩ.

[0368] In this way, 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, improve the conductivity of the battery subunit, and thus increase the charging rate of the battery subunit, which is beneficial to improving the fast charging performance of the battery device.

[0369] In the embodiment of the present application, the resistance of the negative electrode plate has a meaning well known in the art and can be detected using equipment and methods well known in the art, and the detection method is the same as the resistance test method of the positive electrode plate mentioned above.

[0370] 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. Alternatively, the carbon-based material may also include natural graphite. Specifically, the carbon-based material may include graphite particles, or the carbon-based material may include graphite particles and natural graphite.

[0371] Optionally, the carbon-based material is graphite particles. Based on the mass of the graphite particles, the mass proportion of natural graphite may be greater than that of artificial graphite.

[0372] The carbon-based material used for the negative electrode active material layer is at least one of natural graphite and artificial graphite, both of which have excellent conductivity and high theoretical specific capacity. Natural graphite has high crystallinity and a regular layered structure, which facilitates the rapid insertion and extraction of lithium ions, thereby improving the battery's charge and discharge efficiency. Artificial graphite can be precisely tuned through production process control to enhance the cycling stability and extend the service life of individual cells. This can extend the cycle life and charging stability of the charging device 100 in high-power charging scenarios.

[0373] In some embodiments, the volume average particle size Dv50 of the negative electrode film layer may be, but is not limited to, in the range of 8.2 μm to 13.5 μm.

[0374] In the case where 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. In the case of a single-layer film layer, 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 consisting 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 8.2μm and 18.5μm, for example, it can be 8.2μm, 8.5μm, 8.8μm, 9μm, 9.2μm, 9.5μm, 9.8μm, 10μm, 10.2μm, 10.5μm, 10.8μm, 11μm, 11.2μm, 11.5μm, 11.8μm, 12μm, 12.2μm, 12.5μm, 12.8μm, 13μm, 13.2μm, 13.5μm, 14μm, 15μm, 16.2μm, 18μm, 18.5μm or a range consisting of any two of the above values.

[0375] When the negative electrode film layer comprises at least two 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 may be located in one of the at least two film layers, or in at least two of the at least two film layers. The negative electrode film layer may include two film layers, three film layers, four film layers, or even more film layers.

[0376] The volume average particle size (Dv50) of the negative electrode film layer is within the range of 8.2μm-13.5μm, achieving a balanced balance between specific surface area and compaction density. A smaller particle size provides a larger specific surface area, increasing the number of lithium ion reaction sites and improving the charge and discharge rate performance of the individual cells. Meanwhile, an appropriate particle size provides a higher compaction density, reducing the gaps between active materials and increasing the energy density of the individual cells. This achieves a good balance between rate performance and energy density in the individual cells, meeting the charging requirements of the charging device 100 at different charge rates.

[0377] 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 together, 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.

[0378] 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, the solid phase transmission path of lithium ions can be shortened, thereby improving the fast charging performance. On the other hand, the materials are less likely to agglomerate during the preparation process, thereby improving the stability of the materials. The combination 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 conducive to establishing a gradient porosity 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.

[0379] 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 arranged 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 away from the negative electrode current collector, the carbon-based material in the second negative electrode film layer includes graphite particles, and 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.

[0380] The interface between the first negative electrode film layer and the second negative electrode film layer may be regular or irregular, and optionally irregular.

[0381] Optionally, the carbon-based material in the first negative electrode film layer further includes natural graphite.

[0382] The negative electrode film comprises at least two layers, and layered coating can improve the rapid charging performance of individual cells. In particular, when the first and second negative electrode film layers are differentiated, this can create a pore difference in the negative electrode film, reducing the tortuosity of lithium-ion transport and improving the rapid charging performance of the individual cells.

[0383] 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 for improving the compaction 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.

[0384] There is a difference in the particle size between the first negative electrode film layer and the second negative electrode film layer, which can improve the fast charging performance of the single battery cell. Specifically, during the fast charging process, the overpotential of the second negative electrode film layer is usually higher, and the bottleneck of fast charging mainly lies in the second negative electrode film layer. In the embodiment of the present application, the particle size of the second negative electrode film layer is relatively small, which can shorten the solid-phase transmission path of lithium ions, improve the fast charging performance, and improve the problem of lithium plating on the surface of the negative electrode plate.

[0385] Optionally, the negative electrode active material in the first negative electrode film layer is in a granular form, and its volume average particle size Dv50 is 9.5 μm to 18.5 μm, and optionally 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 a range consisting 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 9.5 μm to 18.5 μm, and optionally 9.5 μm to 14.6 μm.

[0386] 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, the solid phase transmission path of lithium ions can be shortened and the fast charging performance can be improved; on the other hand, the material is not easy to agglomerate during the preparation process, which can improve the stability of the material.

[0387] Optionally, the negative electrode active material in the second negative electrode film layer is in a granular form, and a volume average particle size Dv50 thereof is 7.8 μm to 14.3 μm, and optionally 7.8 μm to 11.3 μm. Illustratively, the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film layer is 7.8μm, 8.0μm, 8.2μm, 8.5μm, 8.8μm, 9μm, 9.2μm, 9.5μm, 9.8μm, 10μm, 10.2μm, 10.5μm, 10.8μm, 11μm, 11.3μm, 11.2μm, 11.5μm, 11.8μm, 12μm, 12.2μm, 12.5μm, 12.8μm, 13μm, 13.2μm, 13.5μm, 13.8μm, 14μm, 14.1μm, 14.3μm or a range consisting 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 7.8 μm to 14.3 μm, and optionally 7.8 μm to 11.3 μm.

[0388] 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 easy to agglomerate during the preparation process, which can improve the stability of the material; on the other hand, the combination of the negative electrode active material in the second negative electrode film layer within the above volume average particle size range and the negative electrode active material in the first negative electrode film layer is beneficial to constructing a 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 battery cell.

[0389] In the embodiment of the present application, the volume average particle size Dv50 of the negative electrode active material has a meaning well known in the art and can be detected using equipment and methods well known in the art, and its detection method is the same as the volume average particle size Dv50 test method of the positive electrode active material mentioned above.

[0390] Optionally, the tap density of the carbon-based material in the first negative electrode film layer is less than or equal to the tap density of the carbon-based material in the second negative electrode film layer. The tap density can reflect the filling density of the active material in the film layer. When the tap density of the carbon-based material in the second negative electrode film layer is greater than the tap 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 tap density of the graphite particles in the first negative electrode film layer is less than or equal to the tap density of the graphite particles in the second negative electrode film layer.

[0391] Optionally, the tap density of the carbon-based material in the first negative electrode film layer is 0.82 g / cm 3to 1.21g / cm 3 , for example 0.82 g / cm 3 , 0.85g / cm 3 、0.88g / cm 3 , 0.90g / cm 3 , 0.92g / cm 3 , 0.95g / cm 3 , 0.98g / cm 3 , 1.00g / cm 3 , 1.05g / cm 3 、1.08g / cm 3 , 1.10g / cm 3 , 1.12g / cm 3 , 1.15g / cm 3 , 1.18g / cm 3 , 1.20g / cm 3 , 1.21g / cm 3 When the tap density of the carbon-based material in the first negative electrode film layer is within an appropriate range, the fast charging performance of the single cell can be improved.

[0392] Optionally, the tap density of the carbon-based material in the second negative electrode film layer is 0.90 g / cm 3 Up to 1.25g / cm 3 , for example 0.90g / cm 3 , 0.92g / cm 3 , 0.95g / cm 3 , 0.98g / cm 3 , 1.00g / cm 3 , 1.05g / cm 3 、1.08g / cm 3 , 1.10g / cm 3 , 1.12g / cm 3 , 1.15g / cm 3 , 1.18g / cm 3 , 1.20g / cm 3 , 1.21g / cm 3 , 1.22g / cm 3 , 1.23g / cm 3 , 1.24g / cm 3 ³ , 1.25g / cm 3 When the tap density of the carbon-based material in the second negative electrode film layer is within an appropriate range, the energy density of the single cell can be increased.

[0393] In the embodiments of this application, the tap density of a material is a term generally known in the art and can be measured using instruments and methods known in the art. For example, it can be measured using a powder tap density tester, as described in GB / T 5162-2006. A Dandong Better BT-301 can be used as the tester.

[0394] Optionally, 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 to 7:3, and optionally 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 consisting of any two of the above values. By adjusting the thickness ratio of the first negative electrode film layer to the second negative electrode film layer, the gradient porosity difference between the upper and lower layers can be further increased, the tortuosity of lithium ion transmission can be reduced, and the fast charging capability of the single cell can be improved.

[0395] In some embodiments, the compaction density of the negative electrode film layer of the single cell at 100% charge state is 1.15 g / cm 3 -1.36g / cm 3 .

[0396] Optional 1.25g / cm 3 to 1.36g / cm 3 For example, the compaction density of the negative electrode film layer of a single cell at 100% charge state is 1.15 g / cm 3 , 1.18g / cm 3 , 1.20g / cm 3 , 1.22g / cm 3 , 1.25g / cm 3 , 1.28g / cm 3 , 1.3g / cm 3 , 1.32g / cm 3 , 1.35g / cm 3 , 1.36g / cm 3 Or a range consisting of any two of the above values.

[0397] In the embodiment of the present application, the compaction density of the negative electrode film layer of the single cell at 100% charge state has a meaning well known in the art and can be detected using equipment and methods well known in the art, and the detection method is the same as the compaction density test method of the positive electrode film layer mentioned above.

[0398] When the compaction density of the negative electrode film layer is within the above range, it is beneficial to improve the energy density of the battery cell. Moreover, since the negative electrode active material in the negative electrode film layer is stacked relatively densely, the contact resistance between particles is small, which can further reduce the resistance of the electrode sheet and thus reduce heat generation.

[0399] 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 Up to 1.85g / cm 3 , optional 1.55g / cm 3 Up to 1.65g / cm 3 For example, the powder compaction density of the negative electrode active material under a pressure of 20,000 N is 1.5 g / cm 3 , 1.55g / cm 3 , 1.6g / cm 3 , 1.65g / cm 3 , 1.7g / cm 3 , 1.75g / cm 3 , 1.8g / cm 3³ , 1.85g / cm 3 Or a range consisting of any two of the above values.

[0400] When the powder compaction density of the negative electrode active material at 20,000 N is within the above range, the energy density of the single cell can be improved. Moreover, since the negative electrode active material in the negative electrode film layer can be stacked more densely and the contact resistance between particles is smaller, the resistance of the electrode can be further reduced, thereby reducing heat generation.

[0401] In the embodiments of the present application, the powder compaction density of the material is a well-known meaning in the art and can be tested using methods and equipment known in the art in accordance with the test standard GB / T24533-2009. As an example, a certain amount of negative electrode active material is taken as a sample and placed in a UTM7305 electronic pressure testing machine with a bottom area of ​​1.327 cm 2² The mold was pressurized to 2000 kg (equivalent to 20000 N), maintained for 30 seconds, then released and maintained for 10 seconds, and then the powder compaction density of the negative electrode active material under a force of 20000 N was recorded and calculated.

[0402] In some embodiments, the negative electrode active material has a charge capacity in the range of 350 mAh / g to 480 mAh / g at a 0.1 C rate. For example, the negative electrode active material has a charge capacity in the range of 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 consisting of any two of the foregoing values ​​at a 0.1 C rate.

[0403] When the charge 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.

[0404] In the embodiment of the present application, the charge gram capacity of the negative electrode active material at a rate of 0.1C has a meaning well known in the art and can be detected using equipment and methods well known in the art. The detection method is the same as the charge gram capacity test method of the positive electrode active material at a rate of 0.1C mentioned above.

[0405] In some embodiments, the negative electrode active material layer includes a carbon-based material. Carbon-based materials have high cycle stability and can improve the cycle performance of the single cell. Optionally, the mass proportion 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%.

[0406] 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. The two are used in combination, and the cycle performance of the single battery cell is relatively excellent.

[0407] Optionally, the carbon-based material includes graphite particles, and the graphite particles have a degree of graphitization of 92.0% to 94.5%. Exemplarily, the degree of graphitization of the graphite particles is 92.0%, 92.5%, 93%, 93.5%, 94%, 94.5%, or a range consisting of any two of the foregoing values.

[0408] When the graphitization degree of the graphite particles is within the above range, the electrical conductivity of the graphite particles is relatively excellent, which can reduce the heat generation of the negative electrode plate, reduce the heat generation of the single battery cell, and improve the fast charging performance of the single battery cell.

[0409] In some embodiments, the graphite particles include artificial graphite and a carbon coating. The artificial graphite includes secondary particles, each of which includes a plurality of primary particles. The carbon coating is coated on the surface of the artificial graphite. The carbon in the carbon coating is primarily amorphous carbon. Amorphous carbon refers to a transitional carbon material with a very low degree of graphitization and crystallization, nearly an amorphous morphology (or lacking a fixed shape and periodic structural regularity). In this application, amorphous carbon refers to the product of carbonization of an organic carbon source.

[0410] Artificial graphite includes secondary particles. There are more migration paths for lithium ions in artificial graphite, and the migration paths in primary particles are 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 that can insert and remove lithium ions, making the conductivity of the carbon coating layer relatively excellent, which can reduce the internal resistance of the negative electrode plate and reduce the heat generation of the single battery cell.

[0411] Optionally, the mass content of the carbon coating layer is 2% to 5% based on the mass of the graphite particles. Exemplarily, the mass content of the carbon coating layer is 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a range consisting of any two of the above values.

[0412] When the mass content of the carbon coating layer is within the above range, the internal resistance of the negative electrode plate can be further reduced, and the heat generation of the single battery cell can be reduced.

[0413] In an embodiment of the present application, the graphite particles can be prepared by methods known in the art. For example, the preparation method includes: providing artificial graphite and an organic carbon source, mixing the two, and forming a carbon coating layer on at least a portion of the surface of the artificial graphite particles after carbonization treatment.

[0414] Optionally, the organic carbon source includes one or more of coal tar, petroleum tar, phenolic resin, and coconut shell. Further, the organic carbon source includes petroleum tar. Optionally, the softening point of the coal tar or petroleum tar is below 250°C.

[0415] Optionally, the carbonization temperature is 700° C. to 1800° C. Optionally, the carbonization temperature is 1000° C. to 1300° C. When the carbonization 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 portion of the surface of the artificial graphite.

[0416] Optionally, the carbonization treatment time is 1 hour to 6 hours.

[0417] 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.

[0418] Optionally, based on the mass of the negative electrode active material, the mass content of silicon in the silicon-based material is 0.3% to 10.0%, optionally 1% to 6%. Exemplarily, the mass content of silicon 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 consisting of any two of the above values.

[0419] When the mass content of silicon in the silicon-based material is within the above range, the capacity of the negative electrode active material can be increased, thereby improving the energy density of the single battery cell.

[0420] Alternatively, the silicon-based material may include at least one of elemental silicon, silicon oxide, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy material.

[0421] In some embodiments, the negative electrode active material may include at least one of a tin-based material and lithium titanate in addition to the aforementioned carbon-based material and the optional silicon-based material. The tin-based material may include at least one of elemental tin, tin oxide, and a tin alloy.

[0422] The qualitative and quantitative properties of each substance or element in this application can be detected using appropriate equipment and methods known to those skilled in the art. The relevant detection methods can refer to domestic and international detection standards, domestic and international enterprise standards, etc., and those skilled in the art can also adapt certain detection steps / instrument parameters, etc. from the perspective of detection accuracy to obtain more accurate detection results. A single detection method can be used for qualitative or quantitative determination, or several detection methods can be used in combination for qualitative or quantitative determination.

[0423] For example, the present application may combine JIS / K0131-1996 General Rules for X-ray Diffraction Analysis Methods to perform X-ray powder diffraction testing and qualitative analysis on the negative electrode sheet or negative electrode active material.

[0424] Artificial graphite and natural graphite can be distinguished by the SEM cross-section taken by a scanning electron microscope (SEM). The SEM cross-section of natural graphite shows gaps between the flake structures, while the SEM cross-section of artificial graphite is dense and has no obvious gaps. They can also be distinguished by the XRD spectrum obtained by the X-ray diffraction method. The XRD spectrum of natural graphite shows obvious 2H phase and 3R phase, while the XRD spectrum of artificial graphite only shows 2H phase.

[0425] In some embodiments, the powder resistivity of the negative electrode active material is 0.005 Ω·cm to 0.043 Ω·cm, and may be 0.04 Ω·cm. For example, the powder resistivity of the negative electrode active material may 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 a range consisting of any two of the foregoing values.

[0426] The powder resistivity of the negative electrode active material is relatively low, which makes the resistance of the negative electrode plate relatively low and the heat generation of the single battery cell less.

[0427] In the embodiment of the present application, the powder resistivity of the negative electrode active material is well known in the art and can be detected using equipment and methods well known in the art, such as the powder resistivity test method of the positive electrode active material described above.

[0428] In some embodiments, after a single cell undergoes 10 full charge cycles in the Beginning of Life (BOL) test, the thickness of the first negative electrode film layer is between 15μm and 65μm, such as 15μm, 17μm, 18μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 57μm, 58μm, 60μm, 61μm, 62μm, 63μm, 64μm, 65μm, or a range consisting of any two of these values. When the thickness of the first negative electrode film layer is within the above range, the gradient porosity difference between the first negative electrode film layer and the second negative electrode film layer can be increased, thereby reducing the tortuosity of lithium ion transmission and improving the fast charging capability of the single cell.

[0429] In some embodiments, after a single cell undergoes 10 full charge cycles in the Beginning of Life (BOL) test, the thickness of the second negative electrode film layer is between 15μm and 65μm, such as 15μm, 17μm, 18μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 57μm, 58μm, 60μm, 61μm, 62μm, 63μm, 64μm, 65μm, or a range consisting of any two of these values. When the thickness of the second negative electrode film layer is within the above range, the gradient porosity difference between the first negative electrode film layer and the second negative electrode film layer can be increased, thereby reducing the tortuosity of lithium ion transport and improving the fast charging capability of the single cell.

[0430] In the embodiment of the present application, for example, the battery charging upper limit voltage is 3.65V and the battery discharging cut-off voltage is 2.0V.

[0431] The BOL full charge test steps are as follows: at 25°C, charge the battery to 3.65V at a charge rate of 0.33C, then charge it to 0.05C at a constant voltage of 3.65V, let it stand for 10 minutes, then discharge it to 2.0V at a discharge rate of 0.33C, let it stand for 10 minutes. The above charge and discharge is one cycle, and the cycle is 10 times. Then charge it to 3.65V at a charge rate of 0.33C, then charge it to 0.05C at a constant voltage of 3.65V. In the BOL fully charged state, the negative electrode sheet is disassembled, and a cross-section in the thickness direction of the middle area of ​​the negative electrode sheet is observed using a tomographic scanning electron microscope. The first negative electrode film layer and the second negative electrode film layer are distinguished according to the interface between the two areas, and the thickness of the two areas is measured respectively. For example, the thickness of 10 positions of the first negative electrode film layer is measured respectively, and the average value thereof is calculated as the average thickness of the first negative electrode film layer; the thickness of 10 positions of the second negative electrode film layer is measured, and the average value thereof is calculated as the average thickness of the second negative electrode film layer.

[0432] In some embodiments, after a single cell undergoes an end-of-life (EOL) full charge test, 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, or 70 μm, or a range consisting of any two of these values. When the thickness of the first negative electrode film layer is within the above range, the gradient porosity difference between the first negative electrode film layer and the second negative electrode film layer can be increased, thereby reducing the tortuosity of lithium ion transmission and improving the fast charging capability of the single cell.

[0433] In some embodiments, after a single cell undergoes an end-of-life (EOL) full charge test, 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, or 70 μm, or a range consisting of any two of these values. When the thickness of the second negative electrode film layer is within the above range, the gradient porosity difference between the first negative electrode film layer and the second negative electrode film layer can be increased, thereby reducing the tortuosity of lithium ion transmission and improving the fast charging capability of the single cell.

[0434] In the embodiment of the present application, for example, a battery charging upper limit voltage of 3.65V and a battery discharging cut-off voltage of 2.0V are taken as an example for description.

[0435] The EOL full charge test steps are as follows: at 60°C, charge the battery to 3.65V at a charge rate of 0.33C of the nominal capacity, then charge it to 0.05C at a constant voltage of 3.65V, let it stand for 10 minutes, and then discharge it to 2.0V at a discharge rate of 0.33C, let it stand for 10 minutes. The above charge and discharge cycle is one cycle, and the test is stopped when the battery capacity decays to 80% of the nominal capacity. Then, at 25°C, charge to 3.65V at a constant current of 0.33C and charge to 3.65V at a constant voltage of 0.05C, which is the EOL fully charged state. In the EOL fully charged state, disassemble the negative electrode sheet, and use a tomographic scanning electron microscope to observe the cross-section in the thickness direction of the middle area of ​​the negative electrode sheet. The first negative electrode film layer and the second negative electrode film layer are distinguished according to the interface between the two areas, and the thickness of the two is measured respectively. For example, the thickness of 10 positions of the first negative electrode film layer is measured respectively, and the average value thereof is calculated as the average thickness of the first negative electrode film layer. The thickness of 10 positions of the second negative electrode film layer is measured, and the average value thereof is calculated as the average thickness of the second negative electrode film layer.

[0436] In some embodiments, when the negative electrode film layer adopts a single-layer film layer (as distinguished from the double-layer film layer described above), 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 consisting of any two of the above values. The lithium element in the lithium-containing binder can exist in the form of ions, which can increase the number of freely moving lithium ions in the negative electrode film layer, shorten the distance that lithium ions diffuse to the surface of the negative electrode film layer, increase the lithium ion deintercalation rate, and improve the fast charging performance of the single cell. Optionally, the negative electrode film layer may 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 (for example, polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA) and carboxymethyl chitosan (CMCS).

[0437] Optionally, the mass content of lithium in the lithium-containing binder is 3% to 10%. Exemplarily, the mass content of lithium in the lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two of the above values. The mass content of lithium is calculated based on the mass of the lithium-containing binder. When the mass content of lithium is within the above range, the number of lithium ions that can move freely in the negative electrode film layer is relatively large, which can further shorten the distance that lithium ions 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.

[0438] Exemplarily, the lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, wherein the lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer is derived from a lithium acrylate monomer, an acrylonitrile monomer, an acrylamide monomer, and a hydroxyethyl acrylate monomer, wherein the molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 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 hydroxyethyl acrylate monomer is 35%: 30%: 15%: 20%, or 40%: 20%: 10%: 30%, or 45%: 15%: 20%: 20%, etc.

[0439] The lithium-containing binder of the above material can provide a certain amount of lithium ions for the negative electrode film layer, thereby improving the fast charging performance of the single battery cell. In addition, it is not easy to swell during the charging and discharging process and has a stable structure, thereby improving the cycle performance of the negative electrode film layer during the fast charging and discharging process.

[0440] In other embodiments, when the negative electrode film layer comprises at least two film layers, the negative electrode film layer further comprises a lithium-containing binder.

[0441] 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, wherein 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.

[0442] The mass content of the second lithium-containing binder in the second negative electrode film layer is relatively high, and the second lithium-containing binder provides the second negative electrode film layer with a relatively larger number of freely movable lithium ions, which can further improve the fast charging performance of the single battery cell.

[0443] 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 consisting of any two of the above values. The lithium element in the first lithium-containing binder can exist in ionic form, which can increase the number of freely mobile lithium ions in the negative electrode film layer, shorten the distance that lithium ions diffuse to the surface of the negative electrode film layer, increase the lithium ion deintercalation rate, and improve the fast charging performance of the single cell.

[0444] Optionally, the mass content of lithium in the first lithium-containing binder is 3% to 10%, optionally 3% to 8%. Exemplarily, the mass content of lithium in the first lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two of the above values. When the mass content of lithium is within the above range, the number of lithium ions that can freely move in the negative electrode film layer is relatively large, which can further shorten the distance that lithium ions diffuse to the surface of the negative electrode film layer, increase the rate of lithium ion insertion and extraction, and improve the fast charging performance of the single cell.

[0445] Illustratively, the first lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, wherein the lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer is derived from a lithium acrylate monomer, an acrylonitrile monomer, an acrylamide monomer, and a hydroxyethyl acrylate monomer, wherein the molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 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 hydroxyethyl acrylate monomer is 35%: 30%: 15%: 20%, or 40%: 20%: 10%: 30%, or 45%: 15%: 20%: 20%, etc.

[0446] The lithium-containing binder of the above material can provide a certain amount of lithium ions for the negative electrode film layer, thereby improving the fast charging performance of the single battery cell. In addition, it is not easy to swell during the charging and discharging process and has a stable structure, thereby improving the cycle performance of the negative electrode film layer during the fast charging and discharging process.

[0447] 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 a range consisting of any two of the above values. The lithium element in the second lithium-containing binder can exist in ionic form, which can increase the number of freely mobile lithium ions in the negative electrode film layer, shorten the distance that lithium ions diffuse to the surface of the negative electrode film layer, increase the lithium ion deintercalation rate, and improve the fast charging performance of the single cell.

[0448] The first lithium-containing binder and the second lithium-containing binder may be made of the same material or different materials.

[0449] Optionally, the mass content of lithium in the second lithium-containing binder is 3% to 10%, optionally 3% to 8%. Exemplarily, the mass content of lithium in the second lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two of the above values. When the mass content of lithium is within the above range, the number of lithium ions that can freely move in the negative electrode film layer is relatively large, which can further shorten the distance that lithium ions diffuse to the surface of the negative electrode film layer, increase the rate of lithium ion deintercalation, and improve the fast charging performance of the single cell.

[0450] Exemplarily, the second lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, wherein the lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer is derived from a lithium acrylate monomer, an acrylonitrile monomer, an acrylamide monomer, and a hydroxyethyl acrylate monomer, wherein the molar ratio of the lithium acrylate monomer, the acrylonitrile monomer, the acrylamide monomer, and the 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 hydroxyethyl acrylate monomer is 35%: 30%: 15%: 20%, or 40%, 20%, 10%, 30%, or 45%, 15%, 20%, 20%, etc.

[0451] The lithium-containing binder of the above material can provide a certain amount of lithium ions for the negative electrode film layer, thereby improving the fast charging performance of the single battery cell. In addition, it is not easy to swell during the charging and discharging process and has a stable structure, thereby improving the cycle performance of the negative electrode film layer during the fast charging and discharging process.

[0452] 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 each independently include at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based acrylic resin (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0453] 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.

[0454] In some embodiments, the negative electrode film layer may further optionally include a negative electrode conductive agent. The present application does not particularly limit the type of negative electrode conductive agent. For 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, the weight content of the negative electrode conductive agent is ≤5% based on the total weight of the negative electrode film layer.

[0455] In some embodiments, the negative electrode film layer may further include a negative electrode binder. In some embodiments, the negative electrode binder has a mass content of ≤5% based on the total weight of the negative electrode film layer.

[0456] In some embodiments, the negative electrode film layer may optionally include other additives. Examples of these additives include thickeners, dispersants, and the like, such as sodium carboxymethylcellulose (CMC-Na) and PTC thermistor materials. In some embodiments, the weight content of these additives is ≤ 2% based on the total weight of the negative electrode film layer.

[0457] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. Examples of metal foils include at least one of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base layer. For example, the metal layer may include at least one of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. For example, the polymer base layer may include at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0458] In some embodiments, the ratio CB of the capacity per unit area of ​​the negative electrode film layer to the capacity per unit area of ​​the positive electrode film layer in a single cell is 1.05 to 1.30, and can be optionally 1.07 to 1.15. For example, the ratio CB of the capacity per unit area of ​​the negative electrode film layer to the capacity per unit area of ​​the positive electrode film layer in a 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 consisting of any two of the foregoing values.

[0459] When the ratio CB of the capacity per unit area of ​​the negative electrode film layer to the capacity per unit area of ​​the positive electrode film layer in a single cell is within the above range, there are sufficient sites in the negative electrode film layer for lithium embedding, which can reduce the risk of lithium plating and is conducive to fast charging.

[0460] In the embodiment of the present application, the CB value has a well-known meaning in the art and can be detected using equipment and methods well-known in the art. For example, the capacity per unit area of ​​the negative electrode film layer and the capacity per unit area of ​​the positive electrode film layer are calculated respectively, and the ratio of the two is calculated to obtain the CB value.

[0461] Specifically, take the battery charging upper limit voltage as 3.65V and the battery discharging cut-off voltage as 2.0V as an example for explanation.

[0462] The capacity per unit area of ​​the positive electrode film layer refers to the actual lithium-removable capacity of the positive electrode active material. The test method is as follows: the battery is disassembled in a PRS340 / 11-119-11 Braun glove box, the positive electrode sheet is removed, and assembled into a CR2430 model semi-button battery with a positive electrode-lithium sheet. The area of ​​the positive electrode sheet used is amm 2 , where the electrolyte is 1mol / L LiPF 66 The assembled half-button battery was placed in a solution with EC / EMC / DEC = 3 / 5 / 2 (mass ratio) and then left to stand for 3 hours. The test was carried out at 25°C and charged (Charge) at a voltage range of 2.0V to 3.65V at 0.1C to remove lithium. Then, the battery was discharged (Discharge) at 0.05C to insert lithium to 2.0V. The cycle was repeated twice. The discharge capacity of the second cycle was recorded as YmAh. The actual battery design has a positive electrode sheet length of bmm and a width of cmm. The number of surfaces of the positive electrode active material coated on the positive electrode current collector is d. The capacity of the positive electrode film layer per unit area = Y / (a*b*c*d).

[0463] Specifically, the capacity per unit area of ​​the negative electrode film layer refers to the actual lithium-insertable capacity of the negative electrode active material. The test method is as follows: disassemble the battery in a PRS340 / 11-119-11 Braun glove box, remove the negative electrode plate, and assemble it into a CR2430 model semi-button battery with a negative electrode-lithium plate. The area of ​​the negative electrode plate used is fmm 2² , where the electrolyte is 1mol / L LiPF 66 In a solution with EC / EMC / DEC=3 / 5 / 2 (mass ratio), the assembled half-button battery was left to stand for 3 hours. The test was carried out at 25°C, and 0.1C was used to discharge (Discharge) in the voltage range of 2V-0V to insert lithium, and then 0.05C was used to charge (Discharge) to 2V for lithium removal, and the cycle was repeated twice. The discharge capacity of the second cycle was recorded as ZmAh. The actual battery design has a negative electrode piece length of hmm and a width of imm. The number of surfaces of the negative electrode active material coated on the negative electrode current collector is d, then the negative electrode lithium insertion capacity = Z / (f*h*i*d).

[0464] In some embodiments, the single-side coating weight of the negative electrode film layer is 0.09 g / 1540.25 mm2 -0.17g / 1540.25mm 2

[0465] Optionally, the single-sided coating weight of the negative electrode film layer is 110 mg / 1540.25 mm 2 Up to 150mg / 1540.25mm 2 For example, the coating weight of the negative electrode film on one side is 90 mg / 1540.25 mm 2 、92mg / 1540.25mm 2 、95mg / 1540.25mm 2 、96mg / 1540.25mm 2 、100mg / 1540.25mm 2 、102mg / 1540.25mm 2 、104mg / 1540.25mm 2 、105mg / 1540.25mm 2 、108mg / 1540.25mm 2 、110mg / 1540.25mm 2 、112mg / 1540.25mm 2 、114mg / 1540.25mm 2 、115mg / 1540.25mm 2 、116mg / 1540.25mm 2 、118mg / 1540.25mm 2 、120mg / 1540.25mm 2 、122mg / 1540.25mm 2 、125mg / 1540.25mm 2 、128mg / 1540.25mm 2 、130mg / 1540.25mm 2 、132mg / 1540.25mm 2 、135mg / 1540.25mm 2 、137mg / 1540.25mm 2 、140mg / 1540.25mm 2 、142mg / 1540.25mm 2 、145mg / 1540.25mm 2 、148mg / 1540.25mm 2 、150mg / 1540.25mm 2 、152mg / 1540.25mm 2、155mg / 1540.25mm 2 、160mg / 1540.25mm 2 、165mg / 1540.25mm 2 、170mg / 1540.25mm 2 Or a range consisting of any two of the above values.

[0466] In the embodiment of the present application, the single-sided coating weight of the negative electrode film layer has a meaning well known in the art and can be detected using equipment and methods well known in the art, such as the single-sided coating weight test method of the film layer described above.

[0467] When the single-side coating weight of the negative electrode film layer is within the above range, the heat generated per unit area of ​​the negative electrode sheet will not be too large, and the energy density of the battery cell can be improved.

[0468] 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 consisting of any two of the foregoing 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 consisting of any two of the foregoing values. The negative electrode current collector may be copper.

[0469] When the thickness of the negative electrode current collector is within the above range, the negative electrode current collector has a relatively excellent current flow capacity and can enable the single battery cell to have a higher energy density.

[0470] In the embodiment of the present application, the thickness of the negative electrode current collector has a meaning well known in the art and can be detected using equipment and methods well known in the art, for example, using a solvent to wash away the film layer on the surface of the negative electrode current collector and measuring the thickness of the negative electrode current collector with a micrometer.

[0471] The negative electrode film layer is typically formed by coating the negative electrode slurry onto the negative electrode current collector, drying it, and cold pressing it. The negative electrode slurry is typically formed by dispersing the negative electrode active material, optional conductive agent, optional binder, and other optional additives in a solvent and stirring them uniformly. The solvent can be, but is not limited to, N-methylpyrrolidone (NMP) or deionized water.

[0472] The negative electrode sheet does not exclude other additional functional layers in addition to the negative electrode film layer. For example, in some embodiments, the negative electrode sheet of the embodiments of the present application further includes a negative 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 other embodiments, the negative electrode sheet of the embodiments of the present application further includes a protective layer covering the surface of the negative electrode film layer.

[0473] In some embodiments, the negative electrode plate further includes a negative conductive layer, which is located between the negative electrode film layer and the negative electrode current collector. The negative conductive layer can further improve the conductivity of the negative electrode plate, reduce heat generation of the negative electrode plate, and thus reduce heat generation of the single battery cell.

[0474] In some embodiments, the thickness of the negative electrode conductive layer is 0.5 μm to 2 μm. For example, 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 consisting of any two of the above values.

[0475] When the thickness of the negative electrode conductive layer is within the above range, the conductivity of the negative electrode plate can be further improved, the heat generation of the negative electrode plate can be reduced, thereby reducing the heat generation of the single battery cell, and the energy density of the single battery cell can be improved.

[0476] In the embodiment of the present application, the thickness of the negative electrode conductive layer has a meaning well known in the art and can be detected using equipment and methods well known in the art, and the test method for the negative electrode conductive layer mentioned above can be used.

[0477] 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 pole piece and reducing the heat generation of the single battery 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, thereby improving the structural stability of the negative electrode pole piece.

[0478] In some embodiments, the negative electrode conductive layer may further include other additives, such as thickeners, sodium carboxymethyl cellulose (CMC), PTC thermistor materials, and the like.

[0479] 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 consisting of any two of the above values.

[0480] Illustratively, 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.

[0481] 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 consisting of any two of the above values.

[0482] Illustratively, the negative electrode binder includes one or more of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, aqueous acrylic resin, polyvinyl alcohol, sodium alginate, and carboxymethyl chitosan.

[0483] [Positive electrode]

[0484] In some embodiments, the resistance value of the positive electrode plate is in the range of 0.1Ω-30Ω, optionally 0.1Ω to 5Ω, and further optionally 0.1Ω to 1Ω. Exemplarily, the resistance of the positive electrode plate is 0.1Ω, 0.5Ω, 1Ω, 1.5Ω, 2Ω, 2.5Ω, 3Ω, 3.5Ω, 4Ω, 4.5Ω, 5Ω, 5.5Ω, 6Ω, 6.5Ω, 7Ω, 7.5Ω, 8Ω, 8.5Ω, 9Ω, 9.5Ω, 10Ω, 10.5Ω, 11Ω, 11.5Ω, 12Ω, 12.5Ω, 13Ω, 13.5Ω, 14Ω, 14.5Ω, 15Ω, 15.5Ω, 16Ω, 16.5Ω, 17Ω, 17.5Ω, 18Ω, 18.5Ω, 19Ω, 20Ω, 21Ω, 22Ω, 23Ω, 24Ω, 25Ω, 26Ω, 27Ω, 28Ω, 29Ω, 30Ω or a range consisting of any two of the above values.

[0485] In other examples, the resistance of the positive electrode plate may be in the range of 0.01 mΩ-30 Ω.

[0486] In this way, the conductivity of the battery subunit can be improved, thereby improving the charging performance of the charging device.

[0487] In some embodiments, the compaction density of the positive electrode film layer of the single cell at 100% charge state can be, but is not limited to, 2.5 g / cm 3 -2.8g / cm 3 , optional 2.55g / cm 3 to 2.70g / cm 3 For example, the compaction density of the positive electrode layer of a single cell at 100% state of charge (SOC) is 2.2 g / cm 3 , 2.50g / cm 3 , 2.52g / cm 3 , 2.55g / cm 3 , 2.56g / cm 3 , 2.57g / cm 3 , 2.58g / cm 3 , 2.60g / cm 3 , 2.62g / cm 3 , 2.65g / cm 3 , 2.68g / cm 3 , 2.70g / cm 3 , 2.72g / cm3 , 2.75g / cm 3 , 2.78g / cm 3 , 2.80g / cm 3 Or a range consisting of any two of the above values.

[0488] 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, because the positive electrode active material in the positive electrode film layer is relatively densely packed, the contact resistance between particles is relatively low, which can further reduce the resistance of the electrode sheet and thus reduce the heat generated during fast charging. Therefore, by adjusting the compaction density of the positive electrode film layer to a reasonable range, the single cell can achieve both high energy density and high charge rate performance.

[0489] Optionally, the powder compaction density of the positive electrode active material at 30,000 N is 2.46 g / cm 3 Up to 2.8 g / cm 3 For example, the powder compaction density of the positive electrode active material at 30000N is 2.46g / cm 3 , 2.47g / cm 3 , 2.48g / cm 3 , 2.49g / cm 3 , 2.5g / cm 3 , 2.51g / cm 3 , 2.55g / cm 3 , 2.58g / cm 3 , 2.60g / cm 3 , 2.65g / cm 3 , 2.68g / cm 3 , 2.70g / cm 3 , 2.72g / cm 3 , 2.75g / cm 3 , 2.78g / cm 3 , 2.80g / cm 3 Or a range consisting of any two of the above values.

[0490] When the powder compaction density of the positive electrode active material at 30,000 N is within the above range, the energy density of the single cell can be improved. Moreover, since the positive electrode active material in the positive electrode film layer can be stacked more densely and the contact resistance between particles is smaller, the resistance of the electrode can be further reduced, thereby reducing heat generation.

[0491] In the embodiment of the present application, the powder compaction density of the material is a well-known meaning in the art and can be tested using methods and equipment known in the art. For example, a certain amount of positive electrode active material is taken as a sample and added to a UTM7305 electronic pressure testing machine with a bottom area of ​​1.327 cm 2 The mold was pressurized to 3000 kg (equivalent to 30000 N), maintained for 30 seconds, then released and maintained for 10 seconds, and then the powder compaction density of the positive electrode active material under a force of 30000 N was recorded and calculated.

[0492] In some embodiments, the single-sided coating weight of the positive electrode film layer is 0.2 g / 1540.25 mm 2 Up to 0.37g / 1540.25mm 2 , optional 240mg / 1540.25mm 2 Up to 330mg / 1540.25mm 2 For example, the coating weight of the positive electrode film on one side is 200 mg / 1540.25 mm 2 、210mg / 1540.25mm 2 、220mg / 1540.25mm 2 、230mg / 1540.25mm 2 、240mg / 1540.25mm 2 、250mg / 1540.25mm 2 、260mg / 1540.25mm 2 、270mg / 1540.25mm 2 、280mg / 1540.25mm 2 、290mg / 1540.25mm 2 、300mg / 1540.25mm 2 、310mg / 1540.25mm 2 、320mg / 1540.25mm 2 、330mg / 1540.25mm 2 、340mg / 1540.25mm 2 、350mg / 1540.25mm 2 、360mg / 1540.25mm 2 、370mg / 1540.25mm 2 Or a range consisting of any two of the above values.

[0493] When the single-sided coating weight of the positive electrode film layer is within the above range, the heat generated per unit area of ​​the positive electrode sheet will not be too large, and both the energy density and the charge rate performance of the single battery cell can be improved.

[0494] In the embodiments of the present application, the compaction density of the positive electrode film layer of a single cell at 100% state of charge (SOC) can be tested using the following method: the positive electrode sheet of the single cell at 100% state of charge (SOC) is disassembled and the compaction density of the positive electrode film layer is measured. For example, a single-sided coated positive electrode sheet (if a double-sided coated sheet is used, the positive electrode film layer on one side can be wiped off first) is punched into small discs with an area of ​​S1. The discs are weighed and recorded as M1, and their thickness H1 is measured. The positive electrode film layer of the weighed positive electrode sheet is then wiped off, and the weight of the positive current collector is weighed and recorded as M0, and its thickness H0 is measured. The single-sided coating weight of the positive electrode film layer = (the weight of the positive electrode plate M1 - the weight of the positive electrode collector M0) / S1, the thickness of the positive electrode film layer = the thickness of the positive electrode plate H1 - the thickness of the positive electrode collector H0, 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.

[0495] In some embodiments, the thickness of the positive electrode current collector is 10 μm-15 μm, optionally 12 μm to 15 μm. For example, 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 a range consisting of any two of the above values.

[0496] The positive electrode current collector may be aluminum.

[0497] When the thickness of the positive electrode current collector is within the above range, the positive electrode current collector has a relatively excellent current flow capacity and can enable the single battery cell to have a higher energy density.

[0498] In the embodiment of the present application, the thickness of the positive electrode film layer and the positive electrode current collector has a meaning well known in the art and can be detected by equipment and methods well known in the art. For example, the thickness of the positive electrode sheet is measured with a micrometer, the film layer on the surface of the positive electrode current collector is removed, and the thickness of the positive electrode current collector is measured with a micrometer. When the positive electrode film layer is coated on one side, the thickness of the positive electrode film layer is the thickness of the positive electrode sheet minus the thickness of the positive electrode current collector. When the positive electrode film layer is coated on both sides, the thickness of the positive electrode film layer is (the thickness of the positive electrode sheet minus the thickness of the positive electrode current collector) / 2.

[0499] The positive electrode film layer is typically formed by coating a positive electrode slurry onto a positive electrode current collector, drying it, and cold pressing it. The positive electrode slurry is typically formed by dispersing the positive electrode active material, an optional conductive agent, an optional binder, and any other components in a solvent and stirring them uniformly. The solvent can be, but is not limited to, N-methylpyrrolidone (NMP).

[0500] The positive electrode sheet does not exclude other additional functional layers in addition to the positive electrode film layer. For example, in some embodiments, the positive electrode sheet of the embodiments 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 other embodiments, the positive electrode sheet of the embodiments of the present application further includes a protective layer covering the surface of the positive electrode film layer.

[0501] In some embodiments, the ratio of the thickness of the positive electrode current collector to the thickness of the positive electrode film layer on one side is 0.05 to 0.3. For example, the ratio of the thickness of the positive electrode current collector to the thickness of the positive electrode film layer on one side 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 consisting of any two of the above values.

[0502] When the ratio of the thickness of the positive electrode current collector to the thickness of the single-sided positive electrode film layer is within the above range, the fast charging capability and energy density of the single battery cell can be improved.

[0503] In some embodiments, the powder resistivity of the positive electrode active material is 1 Ω·cm to 27.5 Ω·cm, optionally less than or equal to 20 Ω·cm, optionally less than or equal to 11 Ω·cm. For example, the powder resistivity of the positive electrode active material may 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 consisting of any two of the foregoing values.

[0504] The powder resistivity of the positive electrode active material is relatively low, which makes the resistance of the positive electrode sheet relatively low and the heat generation of the single battery cell less.

[0505] In the embodiments of the present application, the powder resistivity of the material is well known in the art and can be tested using methods and equipment well known in the art, for example, using a PRCD1100 powder resistivity meter according to the test standard GB / T30835-2014.

[0506] In some embodiments, the positive electrode active material has a charge capacity in the range of 150 mAh / g to 170 mAh / g at a 0.1 C rate, and optionally in the range of 157 mAh / g to 170 mAh / g. For example, the positive electrode active material has a charge capacity in the range of 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 consisting of any two of the above values ​​at a 0.1 C rate.

[0507] When the charge 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.

[0508] In the embodiment of the present application, the gram capacity of the active material has a meaning well known in the art and can be tested using equipment and methods well known in the art. The test method for the first coulombic efficiency and the first discharge specific capacity in Appendix G of the national standard GB / T 24533-2019 can be used. Metal lithium is used as the negative electrode and a sample electrode comprising the above-mentioned material is used as the positive electrode to assemble a half-button battery. Under the conditions of 23°C±2°C, the half-button battery is charged and discharged at a rate of 0.1C on a battery tester or other test equipment of equivalent performance to obtain the charge capacity, and then the capacity is divided by the mass of the active material of the electrode to obtain the charge gram capacity parameter.

[0509] In some embodiments, the positive electrode active material includes a lithium-containing phosphate, which includes phosphate particles and a coating layer, the coating layer is coated on the surface of the phosphate particles, and the coating layer contains one or more elements of C, Fe, Ti, Zr, Hf, Ge and Sn.

[0510] The phosphate particles are coated with a coating layer on the surface, which can improve the conductivity of the lithium-containing phosphate with an olivine structure, reduce the powder resistivity of the material, and help increase the migration rate of lithium ions, improve the fast charging capability of the battery, and reduce the heat generation of the single battery cell.

[0511] The mass proportion of the lithium-containing phosphate with an olivine structure in the positive electrode active material can be greater than or equal to 80% and less than or equal to 100%. The positive electrode active material of the present application can be considered to be a lithium-containing phosphate system with an olivine structure. When the mass proportion of the lithium-containing phosphate with an olivine structure is less than 100%, the positive electrode active material can also include commonly used positive electrode active materials, for example, it can include but is not limited to at least one of lithium-containing transition metal oxides. 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.

[0512] Optionally, the mass proportion of the lithium-containing phosphate with an olivine structure in the positive electrode active material is 100%.

[0513] In some embodiments, the phosphate particles include a compound having the formula Li x1 A y1 Me a M b P 1-c X c Y z Compounds wherein 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 comprises one or more of Na, K, and Mg, Me comprises one or more of Mn, Fe, Co, and Ni, M comprises 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, and Ce, X comprises one or more of S, Si, Cl, B, C, and N, and Y comprises one or more of O and F. Phosphate particles have excellent cycling stability, which is beneficial for improving the cycling performance of single cells.

[0514] Exemplarily, the chemical elements in the phosphate particles include at least Li, Fe, P, Al, and Ti, and the mass ratios of the elements are (3-4): (30-35): (15-20): (0.01-0.1): (0.1-0.5).

[0515] Exemplarily, the phosphate particles include one or more of LiFePO4, LiMnPO4, LiNiPO4, and LiCoPO4. The charge and discharge process of a 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 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 practice, the molar content of oxygen O will fluctuate. The above situations are all within the scope of protection of the present application.

[0516] In some embodiments, the coating layer comprises a 3-d Fe 2-d M 2d (PO x2 ) y2 The fast ion conductor M2 includes one or more elements selected from Ti, Zr, Hf, Ge and Sn, 0≤d≤1, 0<x2<5, 0<y2<4.

[0517] Exemplarily, the fast ion conductor is a material having a NASICON structure, such as 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.

[0518] Fast ion conductors with a NASICON structure are materials with ultrafast ion conduction capabilities. They possess abundant three-dimensional lithium ion diffusion and transport channels, and exhibit advantages such as high ion conduction efficiency and strong structural stability during multiple delithiation and insertion processes. Coating phosphate particles with a fast ion conductor containing a NASICON structure can significantly increase the lithium ion transport rate at the positive electrode during multiple delithiation and insertion processes, improve the ionic conductivity of the positive electrode active material, and enhance the rapid charging capability of the individual battery cells. Furthermore, it can increase the specific capacity and the energy density of the corresponding individual battery cells.

[0519] In some embodiments, the coating layer further includes carbon.

[0520] The carbon element and the fast ion conductor can be arranged in layers. For example, the carbon element 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 be coated on 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 facing away from the phosphate particles. Alternatively, the fast ion conductor layer can be coated on 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 facing away from the phosphate particles. Of course, the carbon element and the fast ion conductor can also be arranged in the same layer.

[0521] Optionally, a carbon coating can be formed by carbonizing an organic carbon source (e.g., glucose, polyethylene glycol, etc.) and coating the surface of the fast ion conductor layer. The carbon coating can partially or completely cover the fast ion conductor layer. The carbon coating can significantly improve the electronic conductivity of the phosphate particles, compensating for their poor electronic conductivity and increasing the energy density of the single cell.

[0522] Specifically, the provision of the carbon coating layer enables the positive electrode active material of the present application to have the following advantages:

[0523] The carbon coating layer in the positive electrode active material of the present application provides a suitable channel for the transmission of electrons, which can significantly improve the conduction rate of electrons during multiple lithium delithiation and lithium insertion processes, improve the electronic conductivity of lithium-containing phosphates, improve the charging capacity of the corresponding single battery cells, and also improve the energy density.

[0524] 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 be in full and effective contact with the lithium-containing phosphate, thereby increasing the transmission rate of lithium ions at the interface and improving the charging capacity of the single battery cell.

[0525] Coating a carbon coating on the surface of lithium-containing phosphate can not only improve the conductivity of lithium-containing phosphate, but also improve the structural stability of the positive electrode active material, effectively alleviate the iron dissolution of the positive electrode active material during long-term storage and recycling of single battery cells, thereby improving the cycle life of the single battery cells.

[0526] The positive electrode active material of this application, based on a lithium-containing phosphate, fully leverages the advantages of lithium-containing phosphates: low cost, high reliability, and good cycling stability. It also utilizes coating layers (fast ion conductor layer and carbon coating layer) to address their poor electronic and ionic conductivity. Single cells prepared with this positive electrode active material can achieve improved energy density while maintaining excellent cycling performance.

[0527] In the embodiments of this application, the element content in the positive electrode active material has a meaning well known in the art and can be measured using equipment and methods well known in the art. For example, in accordance with EPA 6010D-2014, it can be measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, instrument model: Thermo ICAP7400). After discharging the single cell to 0% state of charge (SOC), the positive electrode sheet is disassembled, cleaned with DMC and dried, and then calcined at high temperature to remove impurities. Then, 0.4g of the positive electrode active material is weighed and 10ml (50% concentration) of aqua regia is added. The sample is then placed on a plate at 180°C for 30 minutes. After digestion on the plate, the volume is fixed to 100ml, and quantitative analysis is performed using a standard curve method.

[0528] In some embodiments, the degree of graphitization of the positive electrode active material is 0.15 to 0.32, optionally 0.19 to 0.26. For example, the degree of graphitization 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 consisting of any two of the above values.

[0529] 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 battery cell.

[0530] In the embodiment of the present application, a higher degree of graphitization of the material indicates a lower degree of disorder, which can be tested according to the test standard JIS / K 0131-1996 "General Rules for X-ray Diffraction Analysis Methods".

[0531] In some embodiments, the mass content of carbon in the lithium-containing phosphate with olivine structure is 1% to 2%, and the specific surface area of ​​the lithium-containing phosphate with olivine structure is 5m 2 / g to 18m 2 / g.

[0532] Optionally, the mass content of carbon in the lithium-containing phosphate with olivine structure is 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.

[0533] Illustratively, the mass content of carbon in the olivine-structured lithium-containing phosphate is 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, or a range consisting of any two of the above values.

[0534] For example, the specific surface area of ​​the lithium-containing phosphate with olivine structure is 5m 2 / g、6m 2 / g、7m 2 / g、8m 2 / g、9m 2 / g、10m 2 / g、11m 2 / g、12m 2 / g、13m 2 / g、14m 2 / g、15m 2 / g、16m 2 / g、17m 2 / g、18m 2 / g or a range consisting of any two of the above values.

[0535] The carbon element is primarily present in the material in the form of a loose and porous carbon coating, which helps increase the material's specific surface area, facilitates effective contact between the electrolyte and phosphate particles, and promotes the transport of lithium ions at the interface. Furthermore, when the carbon content is within the above range, it can significantly improve the electrical conductivity of the olivine-structured lithium-containing phosphate, which helps enhance the ionic and electronic conductivity of the olivine-structured lithium-containing phosphate, thereby increasing the rapid charging capability and energy density of the single cell.

[0536] In the embodiments of the present application, the specific surface area of ​​the material has a meaning well known in the art and can be detected using equipment and methods well known in the art. For example, according to the test standard GB / T 19587-2017, the positive electrode active material is used as a sample and the specific surface area is tested using a Tri-Star 3020 specific surface area pore size analyzer produced by Micromeritics, USA.

[0537] 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.

[0538] Illustratively, the Dv50 of the positive electrode active material can be 1µm, 1.1µm, 1.15µm, 1.2µm, 1.25µm, 1.3µm, 1.35µm, 1.4µm, 1.45µm, 1.5µm, 1.55µm, 1.6µm, 1.65µm, 1.7µm, 1.75µm, 1.8µm, 1.85µm, 1.9µm, 1.95µm, 2µm, or a range consisting of any two of the above values.

[0539] For example, 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 consisting of any two of the above values.

[0540] The particle size of the positive electrode active material is relatively small, the lithium ion deintercalation path in the positive electrode active material is short, and the heat generation is less. Moreover, the particle size of the above-mentioned positive electrode active material is not too small, and basically no agglomeration will occur during the processing and preparation process, making the performance of the positive electrode active material stable.

[0541] In the embodiment of the present application, the volume average particle size Dv50 of the material refers to the particle size corresponding to 50% of the volume distribution, and the volume average particle size Dv10 of the material refers to the particle size corresponding to 10% of the volume distribution. It can be detected by equipment and methods known in the art. For example, the positive electrode active material is used as a sample, and the Dv50 and Dv10 of the particles are tested by a Mastersizer 2000E laser particle size analyzer according to the test standard GB / T 19077-2016.

[0542] When the positive electrode active material includes other materials in addition to the lithium-containing phosphate having an olivine structure, the volume distribution particle size of the positive electrode active material refers to the volume distribution particle size of all the positive electrode active materials.

[0543] In some embodiments, the olivine-structured lithium-containing phosphate is in a granular form, comprising secondary particles, each of which comprises a plurality of primary particles, and the average particle size of the primary particles is between 200 nm and 500 nm. For example, 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, or 500 nm, or a range consisting of any two of the foregoing values.

[0544] The average particle size of the primary particles is relatively small, the lithium ion deintercalation path in the positive electrode active material is shorter, and the heat generation is less.

[0545] In the embodiments of the present application, secondary particles refer to particles in an agglomerated state formed by the aggregation of two or more primary particles. Primary particles and secondary particles can be easily distinguished by experimental means (such as using a scanning electron microscope to take SEM images), and the average particle size of the primary particles can be obtained by testing in the scanning electron microscope SEM images. The SEM test parameters can be set to: an operating voltage (EHT) of 10.00 kV, an InLens detector, a working distance of 4.6 mm, and a magnification of 1000X.

[0546] In some embodiments, the positive electrode film layer further comprises one or more of a ternary material, lithium phosphate, lithium dihydrogen phosphate, lithium sulfate, lithium sulfite, lithium molybdate, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganate, lithium tartrate, trilithium citrate, lithium nickelate, and lithium ferrite. These materials can serve as lithium replenishers, which can replenish lithium ions in the positive electrode film layer, compensating for irreversible lithium ion loss within the system, increasing capacity, and thereby improving the energy density of the single cell.

[0547] Optionally, the ternary material includes Li x3 A y3 Ni a3 Co b3 Mn c M3 (1-a3-b3-c3) Y3 z3 , wherein, 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 more of Na, K, and Mg, M3 includes one or more 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, and Ce, and Y3 includes one or more of O and F.

[0548] For example, the ternary material includes 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 At least one of O2.

[0549] In some embodiments, the lithium supplement agent comprises 0.5% to 5% by weight of the positive electrode film, such as 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any range consisting of two of the foregoing values. When the lithium supplement agent is within the foregoing range, it can replenish lithium ions in the positive electrode film, compensating for irreversible lithium ion loss within the system, increasing capacity, and thereby improving the energy density of the single cell.

[0550] The lithium replenisher can be located in the same layer as the positive electrode active material, or in different layers. When the lithium replenisher and the positive electrode active material are located in different layers, the lithium replenisher can be located in the lithium replenisher layer, and the positive electrode active material can be located in the positive electrode active material layer. In other words, the positive electrode film layer includes a lithium replenisher layer and a positive electrode active material layer. The positive electrode active material layer can be arranged on at least one side of the positive electrode current collector, and the lithium replenisher layer can be located between the positive electrode active material layer and the positive electrode current collector. Alternatively, the lithium replenisher layer can be arranged on at least one side of the positive electrode current collector, and the positive electrode active material layer can be located between the lithium replenisher layer and the positive electrode current collector. Optionally, the lithium replenisher 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 replenisher in the lithium replenisher layer can be gradually released into the system to compensate for the lithium loss of the battery system.

[0551] In some embodiments, the positive electrode film layer may further include a positive electrode conductive agent. The present application does not particularly limit the type of the positive electrode conductive agent. For example, the positive 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.

[0552] In some embodiments, the mass content of the positive electrode conductive agent is ≤5% based on the mass of the positive electrode film layer.

[0553] 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 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 fluorine-containing acrylic resin. In some embodiments, based on the mass of the positive electrode film layer, the mass content of the positive electrode binder is ≤5%.

[0554] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. Examples of metal foils include at least one of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base layer. For example, the metal material of the metal layer may include at least one of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. For example, the polymer base layer may include at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0555] In some embodiments, the positive electrode plate further includes a positive conductive layer, which is located between the positive electrode film layer and the positive electrode current collector. The positive conductive layer can further improve the conductivity of the positive electrode plate, reduce heat generation of the positive electrode plate, and thus reduce heat generation of the single battery cell.

[0556] In some embodiments, the thickness of the positive electrode conductive layer is 0.5 μm to 2 μm. For example, the thickness of the positive 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 consisting of any two of the above values.

[0557] When the thickness of the positive electrode conductive layer is within the above range, the conductivity of the positive electrode sheet can be further improved, the heat generation of the positive electrode sheet can be reduced, thereby reducing the heat generation of the single battery cell, and the energy density of the single battery cell can be improved.

[0558] In the embodiment of the present application, the thickness of the positive electrode conductive layer has a meaning well known in the art and can be detected using equipment and methods well known in the art, for example, performing a tomographic scan on the positive electrode sheet to directly measure the thickness of the positive electrode conductive layer.

[0559] In some embodiments, the positive electrode conductive layer includes one or more of a positive electrode conductive agent and a positive electrode binder.

[0560] 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 consisting of any two of the above values.

[0561] Illustratively, 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 battery cell.

[0562] 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.

[0563] Illustratively, the positive electrode binder includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, polyacrylic acid, and a fluorinated acrylic resin. The positive electrode binder in the positive electrode conductive layer can improve the bonding between the positive electrode current collector and the positive electrode film layer, thereby enhancing the structural stability of the positive electrode sheet.

[0564] [Isolation film]

[0565] In some embodiments, the isolation membrane includes a base membrane having a porous structure, and the porosity of the base membrane is 20% to 70%, and optionally 35% to 60%. For example, the porosity of the base membrane is 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or a range consisting of any two of the above values.

[0566] In the embodiment of the present application, when the porosity of the base film is within the above range, the migration ability of lithium ions in the separator can be improved, and the internal resistance of the single cell can be further reduced, thereby reducing heat generation.

[0567] In the embodiments of this application, porosity refers to the percentage of the pore volume within the separator to the total volume of the separator. Porosity can be tested in accordance with the standard GB / T36363-2018, "Polyolefin Separators for Single Cells." It should be noted that the actual testing process may vary slightly from the standard to obtain a more accurate test value, depending on instrument differences, test errors, and to minimize the impact of porosity on the test.

[0568] 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.

[0569] Optionally, the base film may be made of polypropylene.

[0570] 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 battery cell and thus reduce heat generation.

[0571] In an embodiment of the present application, the isolation membrane may be a base membrane. Optionally, the isolation membrane further includes a functional layer disposed on at least one side of the base membrane. The functional layer may include inorganic particles to enhance the heat resistance of the isolation membrane. Optionally, the functional layer is disposed on both sides of the base membrane.

[0572] 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, the first functional layer includes first inorganic particles, the second functional layer is located on the other side of the base film, the second functional layer includes composite particles, the composite particles include second inorganic particles and multiple non-fluoropolymer particles, the second inorganic particles are attached to the surface of the non-fluoropolymer particles and / or dispersed in the interior of the non-fluoropolymer particles.

[0573] The first functional layer and the second functional layer have good heat resistance, which can improve the heat resistance of the isolation film.

[0574] Optionally, the first functional layer may include a binder, optionally including at least one of a fluorine-containing binder or a polyacrylic binder, such as polyvinylidene fluoride.

[0575] 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 first inorganic particles can improve the heat resistance of the first functional layer.

[0576] In the embodiment of the present application, the thickness of the base film has a meaning well known in the art, and can be detected using methods and equipment well known in the art. For example, a newly prepared isolation membrane can be taken as a sample, or a single cell that has been discharged (discharged to the lower cut-off voltage so that the battery's charged state is approximately 0% SOC) can be reversely disassembled, and the isolation membrane can be obtained from the single cell. The isolation membrane is dried and used as a sample, and the isolation membrane is cut 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 isolation membrane and its various layers.

[0577] The non-fluorinated polymer particles in the second functional layer refer to polymers that are non-fluorinated polymers. For example, the non-fluorinated polymer particles include an acrylate copolymer. Optionally, the acrylate copolymer includes an acrylate-acrylonitrile-acrylamide-propylene copolymer. Acrylate copolymers have excellent bonding properties and high bonding stability with the base film. The molar ratio of the monomers in the copolymer can be any ratio, for example, a molar ratio of 35%:30%:15%:20%, or 40%:20%:10%:30%, or 45%:15%:20%:20%, etc.

[0578] The second inorganic particles in the composite particles make it difficult for the non-fluoropolymer particles to adhere to each other due to the high temperature treatment during the granulation process, so that the composite particles have pores, which is conducive to the transmission of lithium ions and improves the ion conductivity of the separator. The second inorganic particles can also increase the compression modulus of the composite particles. During the charge and discharge process, the composite particles are not easily deformed, making the structure of the separator more stable, which can improve the dynamic performance of the single battery cell and improve the fast charging performance. Optionally, compared to the first functional layer, the second functional layer is arranged close to the negative electrode sheet. Since the composite particles are not easily deformed, the separator basically does not cause side effects such as extrusion on the negative electrode sheet, making the dynamic performance of the negative electrode sheet stable. Accordingly, the first functional layer is arranged close to the positive electrode sheet.

[0579] 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. These second inorganic particles can enhance the heat resistance of the second functional layer and can form composite particles with non-fluoropolymers to further improve the cycle stability and dynamic performance of the separator, and improve the cycle performance and fast charging performance of the battery cell.

[0580] The average particle size of the second inorganic particles is 5 nm to 100 nm, optionally 10 nm to 100 nm, optionally 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 consisting 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.

[0581] In the embodiment of the present application, the average particle size of the second inorganic particles has a meaning well known in the art and can be detected using equipment and methods well known in the art. For example, after obtaining the isolation film and drying the isolation film as a sample, the isolation film 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 isolation film. The particle sizes of multiple, for example, 50, second inorganic particles are measured, and the average value is calculated as the average particle size of the second inorganic particles.

[0582] In some embodiments, the ionic conductivity of the separator is 0.3 mS / cm to 0.6 mS / cm. For example, the ionic conductivity of the separator 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 consisting of any two of the foregoing values.

[0583] When the ionic conductivity of the separator is within the above range, the separator's ability to transfer lithium ions can be further enhanced, thereby improving the fast charging performance of the single cell.

[0584] In the embodiments of the present application, the ionic conductivity of the isolation membrane has a meaning known in the art and can be detected using equipment and methods known in the art, for example,

[0585] Preparation of 2025 button cells for testing: In a vacuum glove box, a lithium sheet was placed in the negative electrode shell of the battery, and 150 μL of electrolyte was added thereto. The electrolyte was a solution of 1 mol / L LiPF6 in EC / EMC / DEC = 3 / 5 / 2 (mass ratio). Then, an isolation membrane (area of ​​3.14 cm) was placed in the negative electrode shell of the battery. 2 , 12μm thick) to ensure close contact with the lithium sheet. 25μL of electrolyte was then added. Finally, a positive electrode sheet (the one described in Example 1 can be used) was placed on top and packaged. The assembled button cell was removed from the vacuum glove box and allowed to rest for 24 hours before the next test.

[0586] Test: On an electrochemical workstation, at 10 -1 ~10 6 The test is carried out in the frequency range of Hz to obtain the isolation membrane resistance Rb, and the ionic conductivity σ (unit: mS / cm) is calculated by the following formula:

[0587] σ=L / (R b ×S)

[0588] Where: R b is the isolation film resistance, L and S are the thickness and area of ​​the isolation film to be measured respectively.

[0589] In some embodiments, the base film comprises at least one of fiberglass, nonwoven fabric, and polyolefin. The base film may be a single-layer film or a multi-layer composite film, without particular limitation. When the base film is a multi-layer composite film, the materials of the layers may be the same or different, without particular limitation.

[0590] Optionally, the polyolefin includes at least one of polyethylene, polypropylene and polyvinylidene fluoride.

[0591] In some embodiments, the positive electrode sheet, the separator, and the negative electrode sheet can be made into an electrode assembly through a winding process and / or a lamination process.

[0592] Figure 23 and Figure 24 A schematic structural diagram of a single cell is shown.

[0593] In some embodiments, the battery cell 7 may include a housing 20 .

[0594] In some embodiments, the housing 20 of the battery cell 7 can be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell. Alternatively, the housing 20 of the battery cell 7 can be a soft shell, such as a pouch-type soft shell. The soft shell can be made of plastic, such as at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0595] The shell 20 is a hollow structure, and the shell 20 can be used to encapsulate the electrode assembly 10 and the electrolyte.

[0596] The preparation method of the single cell 7 of the embodiments of the present application is well known. In some embodiments, a positive electrode sheet, a separator, a negative electrode sheet, and an electrolyte can be assembled to form a single cell 7. As an example, the positive electrode sheet, the separator, and the negative electrode sheet can be wound and / or laminated to form an electrode assembly 10. The electrode assembly 10 is placed in a housing 20, dried, and then injected with electrolyte. The single cell 7 is then vacuum packaged, allowed to stand, formed, and shaped.

[0597] In some embodiments, the housing 20 includes a shell 21 and an end cover 22 . The shell 21 has an opening, and the end cover 22 covers the opening.

[0598] The shape of the housing 21 can be determined based on the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cylindrical structure, a cylindrical housing can be used; if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped housing can be used. Alternatively, both the electrode assembly 10 and the housing 21 have a rectangular parallelepiped structure.

[0599] In some embodiments, the housing 21 is made of steel, which has high mechanical strength and is not easily deformed, thereby improving the reliability and cycle performance of the battery cells. Optionally, steel accounts for the largest proportion of the housing 21 by mass.

[0600] Optionally, the thickness of the shell 21 is 0.1mm to 0.5mm, optionally 0.2mm to 0.35mm. Exemplarily, the thickness of the shell 21 is 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, or a range consisting of any two of the above values. When the thickness of the shell 21 is within the above range, the mechanical strength of the shell 21 is higher, which can improve the reliability and cycle performance of the single battery cell 7. In addition, the shell 21 occupies less space, and the internal space of the shell 21 is more, which is conducive to improving the energy density of the single battery cell 7.

[0601] From the appearance of the electrode assembly 10, the electrode assembly 10 includes a main body 12, a first pole tab 11 and a second pole tab 13, and the first pole tab 11 and the second pole tab 13 protrude from the main body 12. The first pole tab 11 is the portion of the first pole piece that is not coated with the active material layer, and the second pole tab 13 is the portion of the second pole piece that is not coated with the active material layer. The first pole tab 11 and the second pole tab 13 are used to draw current from the main body 12. The polarity of the first pole piece and the second pole piece are opposite. In other words, one of the first pole piece and the second pole piece is a positive pole piece, and the other of the first pole piece and the second pole piece is a negative pole piece. Of course, the first pole tab 11 can be a positive pole tab, and the second pole tab 13 can be a negative pole tab.

[0602] Taking the first electrode tab 11 as the negative electrode tab and the second electrode tab 13 as the positive electrode tab as an example, the portion of the negative electrode current collector in the negative electrode sheet that is not coated with the active material layer is the negative electrode tab, the active material coated on the negative electrode current collector in the negative electrode sheet constitutes the negative electrode film layer, and the negative electrode film layer and the negative electrode current collector coated with the active material are part of the main body 12. The portion of the positive electrode current collector in the positive electrode sheet that is not coated with the active material layer is the positive electrode tab, the active material coated on the positive electrode current collector in the positive electrode sheet constitutes the positive electrode film layer, and the positive electrode film layer and the positive electrode current collector coated with the active material are part of the main body 12.

[0603] The first electrode tab 11 and the second electrode tab 13 may extend from the same side of the main body 12 , or may extend from opposite sides thereof.

[0604] Optionally, the number of the first electrode tabs 11 located on the same side of the main body 12 is at least one, and optionally at least two. At least two first electrode tabs 11 can increase the current carrying capacity of the first electrode tab 11 .

[0605] Optionally, the number of the second electrode tabs 13 located on the same side of the main body 12 is at least one, and optionally at least two. At least two second electrode tabs 13 can increase the current capacity of the second electrode tabs 13 .

[0606] In some embodiments, the single cell 7 further includes a first electrode terminal 31, which is electrically connected to the first tab 11. Optionally, the first electrode terminal 31 and the first tab 11 are welded, and the first electrode terminal 31 and the first tab 11 may be connected via an adapter or may not be connected via an adapter. Optionally, the first electrode terminal 31 and the first tab 11 are connected without 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 point and help reduce the overall internal resistance of the single cell 7.

[0607] When the first electrode tab 11 is a negative electrode tab, the first electrode terminal 31 is a negative electrode terminal. When the first electrode tab 11 is a positive electrode tab, the first electrode terminal 31 is a positive electrode terminal.

[0608] In some embodiments, the single cell 7 further includes a second electrode terminal 32, which is electrically connected to the second tab 13. Optionally, the second electrode terminal 32 and the second tab 13 are welded, and the second electrode terminal 32 and the second tab 13 can be connected via an adapter or without an adapter. Optionally, the second electrode terminal 32 and the second tab 13 are connected without 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 point and help reduce the overall internal resistance of the single cell 7.

[0609] When the second electrode tab 13 is a negative electrode tab, the second electrode terminal 32 is a negative electrode terminal. When the second electrode tab 13 is a positive electrode tab, the second electrode terminal 32 is a positive electrode terminal.

[0610] Optionally, the number of the first electrode terminals 31 located on the same side of the main body 12 is at least one, and optionally at least two. At least two first electrode terminals 31 can increase the current capacity of the first electrode terminals 31 .

[0611] Further optionally, the flow area of ​​the first electrode terminal 31 on one side is 150mm 2 Up to 1000mm 2 , 200mm is optional 2 Up to 1000mm 2 The flow area of ​​a single-side first electrode terminal 31 refers to the sum of the flow areas of all first electrode terminals 31 located on the same side of the main body 12. The flow area of ​​a first electrode terminal 31 can be understood as the cross-sectional area of ​​the first electrode terminal 31, which is perpendicular to the thickness direction of the end cap 22.

[0612] For example, the flow area of ​​the first electrode terminal 31 on one side may be 150 mm 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 consisting of any two of the above values.

[0613] Optionally, the number of the second electrode terminals 32 located on the same side of the main body 12 is at least one, and optionally at least two. At least two second electrode terminals 32 can increase the current capacity of the second electrode terminals 32 .

[0614] Alternatively, the flow area of ​​the second electrode terminal 32 on one side is 150 mm 2 Up to 1000mm 2 , 200mm is optional 2 Up to 1000mm 2 The flow area of ​​a single-side second electrode terminal 32 refers to the sum of the flow areas of all second electrode terminals 32 located on the same side of the main body 12. The flow area of ​​a second electrode terminal 32 can be understood as the cross-sectional area of ​​the second electrode terminal 32, which is perpendicular to the thickness direction of the end cap 22.

[0615] For example, the flow area of ​​the second electrode terminal 32 on one side may be 150 mm 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 、650mm2 , 700mm 2 , 750mm 2 , 800mm 2 , 850mm 2 , 900mm 2 , 950mm 2 , 1000mm 2 Or a range consisting of any two of the above values.

[0616] like Figure 25 As shown, in some embodiments of the present application, the single cells 7 according to the implementation of the present application can be assembled into a battery module 6. The number of single cells 7 contained 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.

[0617] If there are multiple single cells 7, they can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections within the multiple single cells 7. Multiple single cells 7 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery module 6 can be accommodated within the accommodating portion of the battery module 6. Alternatively, multiple single cells 7 can be first connected in series, in parallel, or in a hybrid connection to form a battery module 6, and then the multiple battery modules 6 can be connected in series, in parallel, or in a hybrid connection to form a single unit and accommodated within the accommodating portion. Optionally, the battery module 6 can further include an accommodating portion having a storage space, and the multiple single cells 7 can be accommodated within the accommodating portion.

[0618] like Figure 26 As shown, in some embodiments, the battery modules 6 can also be assembled into a battery pack 2. The number of battery modules 6 contained 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 a battery module 6 or a battery pack 2.

[0619] The battery pack 2 may include a housing 5 and a plurality of battery modules 6 disposed within the housing 5. The housing 5 includes a first housing portion 5a and a second housing portion 5b. The housing 5 defines a receiving space 5c. The first housing portion 5a covers the second housing portion 5b and forms an enclosed space for receiving the battery modules 6. The plurality of battery modules 6 may be arranged in any manner within the housing 5.

[0620] The first housing portion 5a and the second housing portion 5b overlap each other, and together they define a storage space 5c for accommodating a single battery cell. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Alternatively, both the first housing portion 5a and the second housing portion 5b can be hollow structures with one end open, and the open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0621] In order to improve the sealing performance after the first box body portion 5a and the second box body portion 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body portion 5a and the second box body portion 5b.

[0622] Assuming that the first box portion 5a covers the top of the second box portion 5b, the first box portion 5a can also be called an upper box cover, and the second box portion 5b can also be called a lower box.

[0623] In some embodiments, during the charging process of the battery pack 2 or any single cell constituting the battery pack 2 from 0% state of charge SOC to 100% state of charge SOC, the temperature of the external environment of the battery pack 2 is 30° C.

[0624] In some embodiments, during the charging process of the battery pack 2 or any single cell constituting the battery pack 2 from 10% state of charge (SOC) to 80% state of charge (SOC), the temperature of the external environment of the battery pack 2 is 30° C.

[0625] In some embodiments, the charging process of the battery pack 2 or any single cell constituting the battery pack 2 from 10% state of charge to 80% state of charge includes multiple charging steps, and the difference between the maximum state of charge of any charging step and the maximum state of charge of an 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 a range consisting of any two of the above values.

[0626] The battery pack 2 or any single cell constituting the battery pack 2 includes multiple charging steps from a 10% state of charge to a 40% state of charge. 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 of 5C, 5.5C, 6C, 6.5C, 7C, 7.5C, 8C, 8.5C, 9C, 9.5C, 10C, or a value in the range consisting of any two of the above values.

[0627] The battery pack 2 or any single cell constituting the battery pack 2 also includes multiple charging steps from 40% state of charge to 80% state of charge, the charging rate of any charging step is less than the charging rate of any charging step from 10% state of charge to 40% state of charge, and the charging rate of the step of charging to 80% state of charge is any value between 2.5C and 5C, for example, it can be 2.7C.

[0628] For example, the charging steps of the battery pack 2 or any single cell constituting the battery pack 2 from 10% to 80% can be performed as follows:

[0629] Charge from 10% SOC to 15% SOC at 5.0C constant current.

[0630] Charge from 15% SOC to 20% SOC at 5.0C constant current.

[0631] Charge from 20% SOC to 25% SOC at 5.0C constant current.

[0632] Charge from 25% SOC to 30% SOC at 5.0C constant current.

[0633] Charge from 30% SOC to 35% SOC at 5.0C constant current.

[0634] Charge from 35% SOC to 40% SOC at 5.0C constant current.

[0635] Charge from 40% SOC to 45% SOC at 4.6C constant current.

[0636] Charge from 45% SOC to 50% SOC at 4.3C constant current.

[0637] Charge from 50% SOC to 55% SOC at 4.0C constant current.

[0638] Charge from 55% SOC to 60% SOC at 3.7C constant current.

[0639] Charge from 60% SOC to 65% SOC at 3.4C constant current.

[0640] Charge from 65% SOC to 70% SOC at 3.1C constant current.

[0641] Charge from 70% SOC to 75% SOC at 2.9C constant current.

[0642] Charge from 75% SOC to 80% SOC at 2.7C constant current.

[0643] 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 minutes, and can be optionally 5 minutes to 10.5 minutes. The temperature of the external environment of the battery pack 2 at 10% state of charge is room temperature, for example, 30° C. Exemplarily, the charging time of the battery pack 2 from 10% state of charge to 80% state of charge is 10.5 minutes, 10 minutes, 9.5 minutes, 9 minutes, 8.5 minutes, 8 minutes, 7.5 minutes, 7 minutes, 6.5 minutes, 6 minutes, 5.5 minutes, 5 minutes, or a range consisting of any two of the above values.

[0644] In some embodiments, the volumetric energy density of a single cell may be, but is not limited to, 390 Wh / L to 500 Wh / L, and may optionally be 410 Wh / L to 470 Wh / L. For example, the volumetric energy density of a 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 consisting of any two of the foregoing values. The volumetric energy density of a single cell is relatively high.

[0645] In the embodiments of the present application, the volume energy density of a single cell has a meaning well known in the art and can be detected using equipment and methods well known in the art. For example, the battery charging upper limit voltage is 3.65V and the battery discharge cut-off voltage is 2.0V.

[0646] Place the single cell at 25°C, charge it to 3.65V at a constant current of 0.33C, then charge it to 0.05C at a constant voltage, and discharge it to 2.0V at a constant current of 0.33C. Record the discharge capacity A0 at this time, unit: Ah. Use calipers to measure the length, width, and height of the single cell (generally calculated based on the battery casing size, excluding the height of the electrode terminals and the insulating film outside the casing), calculate the volume of the single cell V0, unit L, and the volume energy density of the single cell VED = (A0 × discharge platform voltage) / V0, unit Wh / L.

[0647] The volumetric energy density of the individual cells ranges from 290Wh / L to 500Wh / L, enabling the energy storage unit to store large amounts of energy within a limited space, providing a stable and sufficient energy source for the high-power output of the charging module 120. During fast charging, the high energy density of the individual cells enables the energy storage unit to continuously power the charging module 120, further optimizing the performance of the charging device 100 and ensuring stable operation at high power output.

[0648] Electrical equipment

[0649] According to a second aspect of the embodiments of the present application, there is provided an electrical device, which includes a battery device according to the embodiments of the present application, such as a single cell, a battery module, or a battery pack. The single cell, battery module, or battery pack can be used as a power source for the electrical device, or as an energy storage unit for 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, 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 vehicle, or an extended-range vehicle. The spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0650] Electrical equipment can choose single cells, battery modules or battery packs according to its usage requirements.

[0651] Figure 27 1 is a schematic diagram of an exemplary electric device 1. The electric device 1 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of the electric device 1, a battery pack or battery module may be used.

[0652] A battery pack 2 is disposed within the electrical device 1. The battery pack 2 can be located at the bottom, top, or rear of the electrical device 1. The battery pack 2 can be used to power the electrical device 1. For example, the battery pack 2 can serve as the operating power source of the electrical device 1 or as the driving power source of the electrical device 1, replacing or partially replacing fuel or natural gas to provide driving power for the electrical device 1.

[0653] The electric 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, to meet the power requirements of the electric device 1 during startup, navigation, and driving.

[0654] As another example, an electric device may be a mobile phone, a tablet computer, a laptop computer, etc. Such an electric device is usually required to be light and thin, and may use a single battery cell as a power source.

[0655] The charging process of the electric device can select the following charging methods:

[0656] Charge from 10% SOC to 15% SOC at 5.0C constant current.

[0657] Charge from 15% SOC to 20% SOC at 5.0C constant current.

[0658] Charge from 20% SOC to 25% SOC at 5.0C constant current.

[0659] Charge from 25% SOC to 30% SOC at 5.0C constant current.

[0660] Charge from 30% SOC to 35% SOC at 5.0C constant current.

[0661] Charge from 35% SOC to 40% SOC at 5.0C constant current.

[0662] Charge from 40% SOC to 45% SOC at 4.6C constant current.

[0663] Charge from 45% SOC to 50% SOC at 4.3C constant current.

[0664] Charge from 50% SOC to 55% SOC at 4.0C constant current.

[0665] Charge from 55% SOC to 60% SOC at 3.7C constant current.

[0666] Charge from 60% SOC to 65% SOC at 3.4C constant current.

[0667] Charge from 65% SOC to 70% SOC at 3.1C constant current.

[0668] Charge from 70% SOC to 75% SOC at 2.9C constant current.

[0669] Charge from 75% SOC to 80% SOC at 2.7C constant current.

[0670] In some embodiments, the charging time of the electrical device from a 10% state of charge to an 80% state of charge is less than or equal to 10.5 minutes, and may be 5 minutes to 10.5 minutes. The temperature of the external environment of the battery pack 2 at a 10% state of charge is room temperature, for example, 30° C. Exemplarily, the charging time of the battery pack 2 from a 10% state of charge to an 80% state of charge is 10.5 minutes, 10 minutes, 9.5 minutes, 9 minutes, 8.5 minutes, 8 minutes, 7.5 minutes, 7 minutes, 6.5 minutes, 6 minutes, 5.5 minutes, 5 minutes, or a range consisting of any two of the above values.

[0671] Example

[0672] The following examples describe the disclosure of the present invention in more detail. These examples are intended for illustrative purposes only, as various modifications and variations within the scope of the disclosure of the present invention will be apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by mass, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0673] Example 1

[0674] 1. Preparation of positive electrode sheet

[0675] The positive electrode sheet includes a positive electrode current collector, a positive electrode conductive layer on the positive electrode current collector and a positive electrode film layer. The positive electrode current collector is an aluminum foil with a thickness of 10 μm.

[0676] The positive conductive layer on the positive current collector is a film layer formed by evenly mixing the positive electrode conductive agent superconducting carbon, the positive electrode binder polyvinylidene fluoride (PVDF) and the solvent N-methylpyrrolidone (NMP), and then coating it on the current collector surface and drying it. The thickness is 1μm. The mass content of the positive electrode conductive agent in the positive conductive layer is 40%, and the mass content of the positive electrode binder is 60%.

[0677] The positive electrode film layer includes a positive electrode slurry (the solvent is N-methylpyrrolidone (NMP)) uniformly coated on the surface of the positive electrode conductive layer, and a film layer formed after drying and cold pressing. The positive electrode film layer includes a positive electrode active material, a binder polyvinylidene fluoride (PVDF) and a conductive agent acetylene black in a weight ratio of 97:2:1.

[0678] The positive electrode active material includes lithium iron phosphate and a coating layer, which is coated on the surface of the lithium iron phosphate and includes lithium iron...

Claims

1. A charging device, characterized in that: include: 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, the energy storage module being configured to provide a first direct current; a charging module connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, the charging module being configured to output charging based on the first DC power, the maximum charging output power of the charging module being greater than or equal to 350 kilowatts, and / or the rated charging output power of the charging module being greater than or equal to 290 kilowatts; an input module, the input module being adapted to provide charging energy to each of the energy storage units; When the number of the energy storage unit is multiple, the energy storage unit and the charging module are configured to charge the electrical device with different charging output powers; The ratio of the maximum charging output power of the charging module to the maximum output power of the input module is greater than 1 and less than or equal to 15, and / or the ratio of the rated charging output power of the charging module to the rated output power of the input module is greater than 1 and less than or equal to 15; The 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 the first direct current. The charging module includes a charging gun and at least one charging module power conversion unit. The positive input terminal of each charging module power conversion unit is connected to the second positive power supply terminal of the energy storage module, the positive output terminal of each charging module power conversion unit 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 charging module power conversion unit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

2. The charging device according to claim 1, characterized in that Each of the energy storage units includes a battery subunit, and a 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 1-4.

3. The charging device according to claim 1, wherein: 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), where the value range of n2 is 94%-99%, and the value range of n3 is 4-6.

4. The charging device according to claim 1, wherein: 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 watt-hours / liter.

5. The charging device 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 device 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 device 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 device according to claim 5, characterized in that The electrolyte further includes an organic solvent, and the organic solvent includes a chain carboxylate solvent. Based on the total mass of the solvent, the mass content A of the chain carboxylate solvent satisfies: 5%≤A≤75%, Wherein, the chain carboxylate solvent includes a compound 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 device according to claim 8, characterized in that 40%≤A≤75%。 10. The charging device according to any one of claims 1 to 4, characterized in that: Each of the energy storage units includes a battery subunit, each of the battery subunits includes a single battery cell, each of the single battery cell includes a negative electrode plate, each of the negative electrode plates includes a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, each of the negative electrode film layer includes a negative electrode active material, each of the negative electrode active materials includes a carbon-based material, and each of the carbon-based materials includes at least one of natural graphite and artificial graphite.

11. The charging device 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 arranged in a stacked manner, 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 device 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 negative electrode plate, the negative electrode plate includes a negative electrode current collector and a negative electrode film layer located at least on one side of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material; The compaction density of the negative electrode film layer of the single cell is 1.15g / 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 device 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 located at least 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 when the cell is 100% charged. 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 device 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 collector and a positive electrode film layer located at least on one side of the positive electrode collector, and the thickness of the positive electrode collector is 10μm-15μm.

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

16. The charging device 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 positive electrode plate, the positive electrode plate 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; 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 selected from the group consisting of C, Fe, Ti, Zr, Hf, Ge, and Sn.

17. The charging device 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 device according to any one of claims 1 to 4, characterized in that: Each of the energy storage units includes a battery subunit, each of the battery subunits includes a positive electrode plate, each of the positive electrode plates includes a positive electrode current collector, a positive electrode conductive layer and a positive electrode film layer, the positive electrode film layer is provided on at least one side of the positive electrode current collector, the positive electrode conductive layer is located between the positive electrode current collector and the positive electrode film layer, and the thickness of the positive electrode 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. The negative electrode plate includes a negative electrode current 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 current collector, and the negative electrode conductive layer is located between the negative electrode current 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 device 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. 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 device according to claim 18, wherein 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% to 80%.

21. The charging device according to claim 1, 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 electrical energy of the battery subunit.

22. The charging device according to claim 21, characterized in that At least some of the one or more energy storage units further include a first power conversion subunit, the first power conversion subunit being 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 being configured to convert the electrical energy of the battery subunit into the second direct current; Wherein, when 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.

23. The charging device according to claim 21, characterized in that At least some of the one or more energy storage units further include a first switch subunit, the first switch subunit being 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 being 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 the 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 the second direct current.

24. The charging device according to claim 23, 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.

25. The charging device according to any one of claims 22 to 24, 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 to each of the energy storage units 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.

26. The charging device according to any one of claims 22 to 24, 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.

27. The charging device according to claim 26, 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 which 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. 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.

28. The charging device according to claim 27, 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.

29. The charging device according to claim 26, wherein: 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.

30. The charging device according to claim 26, wherein: The input module includes multiple tenth power conversion subunits, each of which is connected to one of the energy storage units, and the multiple 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.

31. The charging device according to any one of claims 22 to 24, characterized in that: The 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 exchange information with an external device through the wireless communication module.

32. A charging pile, characterized in that: Comprising a charging device according to any one of claims 1-31.

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