Charging system and charging pile

Abstract

The application discloses a charging and storing system and a charging pile. The charging and storing system comprises a charging device, which comprises: 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 end and a first negative power supply end, the one or more energy storage units being connected to a second positive power supply end and a second negative power supply end of the energy storage module through the first positive power supply end and the first negative power supply end, and the energy storage module being configured to provide first direct current; and a charging module, the charging module being connected to the second positive power supply end and the second negative power supply end of the energy storage module, the charging module being configured to be suitable for charging output 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. In this way, by configuring the energy storage unit inside the charging device, large-power charging, such as supercharging / fast charging, can be realized at low cost.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to the following patent applications, the contents of which are incorporated herein by reference in their entirety:

[0003] PCT International Patent Application No. PCT / CN2024 / 093513, titled “Charging device, charging pile and charging and storing system” filed on May 15, 2024;

[0004] PCT International Patent Application No. PCT / CN2024 / 102652, titled “Battery cell, battery and electric device” filed on June 28, 2024. TECHNICAL FIELD

[0005] The present application relates to the technical field of charging, in particular to a charging and storing system and a charging pile. BACKGROUND

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

[0007] However, the fast charging / super charging charging piles in the related art all need to be additionally configured with a transformer or to be expanded with a transformer, which is not conducive to the rapid access of the fast charging / super charging charging piles and will increase more costs. SUMMARY

[0008] In view of the above problems, the present application provides a charging and storing system and a charging pile, which, without the need for additional configuration of a transformer or expansion of a transformer, can realize fast charging of the charging device, such as fast charging / super charging, by configuring an energy storage unit inside the charging device, and can reduce the costs caused by the addition of a transformer or the expansion of a transformer.

[0009] In a first aspect, the application provides a charging and storing system, comprising a charging device, the charging device comprising: a storing module, the storing module comprising one or more storing units, each storing unit having a first positive power supply end and a first negative power supply end, the one or more storing units being connected to a second positive power supply end and a second negative power supply end of the storing module through the first positive power supply end and the first negative power supply end, the storing module being configured to provide first direct current; an input module, the input module being adapted to provide charging energy for each storing unit; and a charging module, the charging module being connected to the second positive power supply end and the second negative power supply end of the storing module, the charging module being configured to be adapted to perform charging output 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, the ratio between the maximum charging output power of the charging module and the maximum output power of the input module being 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 being greater than 1 and less than or equal to 15, when the number of storing units is a plurality, the storing units and the charging module being configured to be able to charge the electric device at different output powers.

[0010] In the technical solution of the embodiments of the application, by configuring the storing units inside the charging device without the need for additional configuration of transformers or expansion of the transformers, not only the fast charging of the charging device, such as fast charging / ultra-fast charging, can be achieved, but also the cost caused by the addition of transformers or expansion of the transformers can be reduced.

[0011] The input module can be adapted to provide charging energy for the storing units. In different power consumption environments, whether it is an old city area with relatively tight power supply or a remote area sensitive to infrastructure construction cost, the charging device can realize fast charging function by the cooperation of the input module and the storing module without relying on external complex power supply upgrade, thereby enhancing the applicability and flexibility of the charging device in various scenarios.

[0012] In some embodiments, each storing unit comprises a battery subunit, and the ratio between the rated output power of the input module and the rated energy of the battery subunit is greater than or equal to 1 / n1, where n1 is in the range of 1-4.

[0013] Thus, when the input power is small and the output power is large, the battery sub-units can charge the electrical equipment at different charging rates, so as to adjust the charging rate according to the charging demand of the electrical equipment in the charging process or different charging time periods, so that the charging device can reasonably use the stored energy to charge the electrical equipment, the energy stored in the charging device is effectively utilized, the performance-cost ratio of the whole charging device is improved, and the stability of the charging device is improved. In different charging processes, the charging device plays a "buffer" role between the power grid and the electrical equipment, reducing the impact of large power output on the power grid.

[0014] In some embodiments, each energy storage unit includes a battery sub-unit, and the ratio between the rated energy of the battery sub-unit and the rated charging output power of the charging module is greater than or equal to 1 / (n2*n3), where n2 is in the range of 94% to 99%, and n3 is in the range of 4 to 6.

[0015] Thus, while ensuring the charging performance, the reliability of the charging device is also considered. When the rated energy of the battery sub-unit is matched with the rated charging output power of the charging module, the battery sub-unit can stably provide energy for the charging module during the charging process, reducing the instability or interruption of the charging power caused by insufficient energy supply. Taking n2=94% and n3=6 as an example, the larger denominator requires the battery sub-unit to have a relatively high rated energy to match the power of the charging module. This enables the charging device to work stably and continuously during a long-time and high-power charging process, reduces the probability of failure, and reduces maintenance costs, thereby improving the performance-cost ratio in terms of the service life of the charging device.

[0016] In some embodiments, each energy storage unit includes a battery sub-unit, and the ratio between the rated energy of the battery sub-unit and the rated power of the battery sub-unit is less than or equal to 1 / 3, and / or the volumetric energy density of the battery sub-unit is greater than or equal to 380 Wh / L.

[0017] When the charging device outputs large power (the maximum charging output power of the charging module is greater than 350 kW), the rated energy of the battery sub-unit is matched with the rated power, reducing the power grid fluctuations caused by the need for the power grid to supply power due to insufficient rated energy of the battery sub-unit caused by large power output. This is conducive to improving the reliability and stability of the charging device, and enables the charging device to work stably and continuously during large power output, reduces the probability of failure, and reduces maintenance costs, thereby improving the performance-cost ratio in terms of the service life of the charging device.

[0018] In some embodiments, each energy storage unit includes a battery sub-unit, the battery sub-unit includes a single battery cell, the single battery 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 to 1.0 mol / L.

[0019] By setting the electrolyte to include lithium hexafluorophosphate at the above concentration, the battery subunit has a higher ionic conductivity, thereby improving the charging rate of the charging device, and also has a higher interface stability and a higher thermal stability; lithium hexafluorophosphate has a smaller influence 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 a higher reliability when the power output is above 350 kW.

[0020] In some embodiments, the electrolyte further includes an organic solvent, and the organic solvent includes a carbonate-based solvent.

[0021] Adding a carbonate-based solvent to the electrolyte can improve various performances of the battery subunit, for example, the charging and discharging efficiency, cycle performance, low-temperature performance, and high-voltage stability of the battery subunit can be improved.

[0022] In some embodiments, the electrolyte salt further includes a fluorine-containing sulfonimide salt, and the concentration of the fluorine-containing sulfonimide salt is in the range of 0.2 mol / L-0.5 mol / L.

[0023] Since the fluorine-containing sulfonimide salt has the characteristics of low viscosity and high ionic conductivity, the electrolyte including the fluorine-containing sulfonimide salt at the above concentration is conducive to improving the charging rate of the battery subunit, thereby improving the charging rate of the charging device.

[0024] In some embodiments, the electrolyte further includes an organic solvent, and the organic solvent includes a chain carboxylic acid ester-based solvent, and the mass content A of the chain carboxylic acid ester-based solvent based on the total mass of the solvent satisfies: 5%≤A≤75%,

[0025] The chain carboxylic acid ester-based solvent includes a compound having the following structure:

[0026]

[0027] 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.

[0028] In this technical solution, the solvent includes a carboxylic acid ester-based solvent, so that the electrolyte can have a higher ionic conductivity and a relatively lower viscosity, which is conducive to further improving the rapid charging performance of the charging device, such as the fast charging performance and / or the super charging performance.

[0029] In some embodiments, 40%≤A≤75%.

[0030] Setting A to be greater than or equal to 40% and less than or equal to 75% can better achieve the purpose of rapid charging of the charging device.

[0031] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a single cell, the single cell comprises a negative pole tab, the negative pole tab comprises a negative pole current collector and a negative pole film layer arranged on at least one side of the negative pole current collector, the negative pole film layer comprises a negative pole active material, and the negative pole active material comprises a carbon-based material, the carbon-based material comprises at least one of natural graphite and artificial graphite.

[0032] The carbon-based material using at least one of natural graphite and artificial graphite as the negative pole active material has good electrical conductivity and high theoretical specific capacity. The natural graphite has high crystallinity and regular layered structure, which is beneficial to the rapid embedding and extraction of lithium ions, thereby improving the charging and discharging efficiency of the battery. The artificial graphite can precisely adjust its microstructure and performance by controlling the production process, thereby enhancing the cycle stability of the battery and prolonging the service life of the battery.

[0038] In some embodiments, the volume average particle size Dv50 of the negative pole film layer is in the range of 8.2 μm-13.5 μm.

[0034] Therefore, this particle size range can balance the specific surface area and the compaction density. Smaller particle size can provide larger specific surface area, increase the reaction sites of lithium ions, and improve the charging and discharging rate performance of the battery. Appropriate particle size can ensure higher compaction density, reduce the voids between active materials, and improve the energy density of the battery, thereby achieving a good balance between the rate performance and the energy density of the battery.

[0035] In some embodiments, the negative pole film layer comprises a first negative pole active material layer and a second negative pole active material layer arranged in a stack, the first negative pole active material layer is located on the side close to the negative pole current collector, the volume average particle size Dv50 of the negative pole active material in the first negative pole active material layer is in the range of 9.5 μm-18.5 μm, and the volume average particle size Dv50 of the negative pole active material in the second negative pole active material layer is in the range of 7.8 μm-14.3 μm.

[0036] When the volume average particle size Dv50 of the negative pole active material in the first negative pole active material layer and the volume average particle size Dv50 of the negative pole active material in the second negative pole active material layer are in the above ranges, on the one hand, the solid-phase transmission path of lithium ions can be shortened, and the rapid charging performance can be improved. On the other hand, the material is not prone to agglomeration during the preparation process, and the stability of the material can be improved. The negative pole active material in the second negative pole active material layer and the negative pole active material in the first negative pole active material layer in the above volume average particle size range cooperate to facilitate the construction of the gradient pore difference between the second negative pole active material layer and the first negative pole active material layer, reduce the tortuosity of lithium ion transmission, and improve the rapid charging performance of the battery single cell.

[0037] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a single battery cell, the single battery cell comprises a negative electrode tab, the negative electrode tab comprises a negative electrode current collector and at least one negative electrode film layer located on one side of the negative electrode current collector, the negative electrode film layer comprises a negative electrode active material layer.

[0038] The compaction density of the negative electrode film layer is 1.15 g / cm 3 -1.36 g / cm 3 , and / or the single-side coating weight of the negative electrode film layer is 0.09 g / 15 40.25 mm 2 -0.17 g / 15 40.25 mm 2 .

[0039] When the compaction density of the negative electrode film layer is in the above range, the energy density of the battery cell can be improved, and because the negative electrode active material in the negative electrode film layer is packed more closely, the contact resistance between particles is smaller, which can further reduce the resistance of the tab and thus reduce heat generation.

[0040] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a single battery cell, the single battery cell comprises a positive electrode tab, the positive electrode tab comprises a positive electrode current collector and at least one positive electrode film layer located on one side of the positive electrode current collector, the positive electrode film layer comprises a positive electrode active material layer;

[0041] The compaction density of the positive electrode film layer is 2.5 g / cm 3 -2.8 g / cm 3 .

[0042] When the compaction density of the positive electrode film layer is in the above range, the energy density of the battery cell can be improved, and because the positive electrode active material in the positive electrode film layer is packed more closely, the contact resistance between particles is smaller, which can further reduce the resistance of the tab and thus reduce heat generation.

[0043] In some embodiments, the single-side coating weight of the positive electrode film layer is 0.2 g / 15 40.25 mm 2 -0.37 g / 15 40.25 mm 2 .

[0044] When the single-side coating weight of the positive electrode film layer is in the above range, the heat generation per unit area of the positive electrode tab will not be too large, and the energy density of the battery cell can be improved.

[0045] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a single battery cell, the single battery cell comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer located at least on one side of the positive electrode current collector, and the thickness of the positive electrode current collector is 10-15 microns.

[0046] When the thickness of the positive electrode current collector is in the above range, the overcurrent capacity of the positive electrode current collector is excellent, and the battery cell can have a higher energy density.

[0047] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a single battery cell, the single battery cell comprises a separator film, the separator film comprises a base film with a porous structure, and the porosity of the base film is 20-70%.

[0048] When the porosity of the base film is in the above range, the migration ability of lithium ions in the separator film can be improved, and the internal resistance of the battery cell can be reduced, thereby reducing heat generation.

[0049] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a positive electrode sheet, the positive electrode sheet comprises 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 comprises a positive electrode active material, and the positive electrode active material comprises a lithium-containing phosphate.

[0050] The lithium-containing phosphate comprises phosphate particles and a coating layer, the coating layer is coated on at least part of the surface of the phosphate particles, and the coating layer comprises one or more elements of C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0051] In this technical solution, the positive electrode coating layer has excellent ion and electron conductivity, which can improve the ion and electron conductivity of the positive electrode active material, thereby effectively improving the charge rate of the battery subunit and the rapid charging performance of the charging device, and being conducive to improving the rapid charging performance of the battery device.

[0052] In some embodiments, the coating layer comprises a fast ion conductor, wherein the fast ion conductor comprises a compound with a general formula of Li 3-d Fe 2- d M 2d (PO4)3, M2 comprises at least one element of Ti, Zr, Hf, Ge, and Sn, and 0≤d≤1.

[0053] Since the fast ion conductor has high ion conductivity, it is conducive to the diffusion and transmission of lithium ions, which can further improve the charge rate of the battery subunit, the rapid charging performance of the charging device, and the rapid charging performance of the battery device.

[0054] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode current 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 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 0.5-2 microns.

[0055] In this way, the diffusion path of lithium ions can be shortened, thereby improving the rate performance of the battery subunit and facilitating the improvement of the rapid charging performance of the battery device.

[0056] In some embodiments, 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.

[0057] The mass content of the positive electrode conductive agent is set in the range of 30%-50%, which can improve the electron transmission efficiency in the positive electrode sheet and further improve the rate performance of the battery subunit.

[0058] In some embodiments, the positive electrode conductive layer comprises 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.

[0059] The mass content of the positive electrode binder is set 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 subunit.

[0060] In some embodiments, each energy storage unit comprises a battery subunit, the battery subunit comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode current 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 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 0.5-2 microns.

[0061] In this way, the diffusion path of lithium ions can be shortened, thereby improving the rate performance of the battery subunit and facilitating the improvement of the rapid charging performance of the battery device.

[0062] In some embodiments, 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.

[0063] The mass content of the positive electrode conductive agent is set in the range of 30%-50%, which can improve the electron transmission efficiency in the positive electrode sheet and further improve the rate performance of the battery subunit.

[0064] In some embodiments, the negative electrode conductive layer includes a negative electrode binder, and a mass content of the negative electrode binder is in a range from 60% to 80% based on a total mass of the negative electrode conductive layer.

[0065] The technical solution sets the mass content of the negative electrode binder in a range from 60% to 80%, which can reduce the possibility of cracking or peeling of the negative electrode sheet during the cycle process, thereby improving the cycle life of the battery subunit and being beneficial to improving the cycle life of the battery device.

[0066] In some embodiments, the one or more energy storage units are connected in series and / or parallel between the second positive power supply end and the second negative power supply end of the energy storage module through the first positive power supply end and the first negative power supply end to provide the first direct current. In this way, the function of small-power input and large-power output of the charging and storage system can be met, thereby improving the adaptability of the charging and storage system.

[0067] 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 electric energy of the battery subunit.

[0068] In some embodiments, at least part of the one or more energy storage units further includes a first power conversion subunit connected with the first positive power supply end and the first negative power supply end of the corresponding battery subunit and energy storage unit, and configured to convert the electric energy of the battery subunit into the second direct current; and in the case that the energy storage unit does not include the first power conversion subunit, the battery subunit is directly connected with the first positive power supply end and the first negative power supply end of the corresponding energy storage unit to provide the second direct current. In this way, the flexibility of charging can be improved.

[0069] In some embodiments, at least part of the one or more energy storage units further includes a first switch subunit connected with the first positive power supply end and the first negative power supply end of the corresponding battery subunit and energy storage unit, and configured to connect the first positive power supply end and the first negative power supply end of the corresponding battery subunit and energy storage unit when turned on to provide the second direct current; and in the case that the energy storage unit does not include the first switch subunit, the battery subunit is directly connected with the first positive power supply end and the first negative power supply end of the corresponding energy storage unit to provide the second direct current. In this way, the energy storage unit can be protected.

[0070] In some embodiments, at least part of the one or more energy storage units further comprises a first power conversion subunit and a first switch subunit, the first power conversion subunit and the first switch subunit are connected in series between the first positive power terminal and the first negative power terminal of the corresponding battery subunit and the energy storage unit, 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 comprise the first power conversion subunit and the first switch subunit, the battery subunit is directly connected to the first positive power terminal and the first negative power terminal of the corresponding energy storage unit to provide the second direct current. In this way, the flexibility of charging and the protection of the energy storage unit can be improved.

[0071] In some embodiments, the input module comprises an input interface connected to the second positive power terminal and the second negative power terminal of the energy storage module, and is configured to provide charging energy for each energy storage unit based on the third direct current provided by the first external power source; or the input module comprises a second power conversion subunit connected to the second positive power terminal and the second negative power terminal of the energy storage module, and is configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power source. In this way, AC input or DC input can be allowed to charge the energy storage unit.

[0072] In some embodiments, the charging module comprises a third power conversion subunit and a charging gun, the positive input terminal and the negative input terminal of the third power conversion subunit are connected to the second positive power terminal and the second negative power terminal of the energy storage module, the positive output terminal and the negative output terminal of the third power conversion subunit are connected to the positive input terminal and the negative input terminal of the charging gun, and the third power conversion subunit is configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun is not common negative.

[0073] In some embodiments, the charging module comprises 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 terminal of the energy storage module, the positive output terminal of the fourth power conversion subunit is connected to the positive input terminal of the charging gun, the negative input terminal of the charging gun is connected to the second negative power terminal of the energy storage module, and the fourth power conversion subunit is configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun is common negative, and the cost can be reduced.

[0074] In some embodiments, the energy storage module further comprises a selection unit connected to the one or more energy storage units, and configured to select at least one energy storage unit from the one or more energy storage units to be connected to the second positive power terminal and the second negative power terminal of the energy storage module to provide the first direct current. In this way, the flexibility of charging can be improved.

[0075] In some embodiments, the second positive power supply terminal and the second negative power supply terminal of the energy storage module each include one, the selection unit includes a plurality of second switch sub-units, each second switch sub-unit is connected with one 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 with 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 with the second positive power supply terminal of the energy storage module in a conducting state.

[0076] In some embodiments, the charging module includes a fifth power conversion sub-unit and a charging gun, the positive input terminal and the negative input terminal of the fifth power conversion sub-unit are connected with the second positive power supply terminal and the second negative power supply terminal of the energy storage module, the positive output terminal and the negative output terminal of the fifth power conversion sub-unit are connected with the positive input terminal and the negative input terminal of the charging gun, and the fifth power conversion sub-unit is configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun does not share a negative terminal.

[0077] In some embodiments, the charging module includes a sixth power conversion sub-unit and a charging gun, the positive input terminal of the sixth power conversion sub-unit is connected with the second positive power supply terminal of the energy storage module, the positive output terminal of the sixth power conversion sub-unit is connected with the positive input terminal of the charging gun, the negative input terminal of the charging gun is connected with the second negative power supply terminal of the energy storage module, and the sixth power conversion sub-unit is configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun shares a negative terminal, and the cost can be reduced.

[0078] In some embodiments, the second positive power supply terminal of the energy storage module includes a plurality of, the second negative power supply terminal of the energy storage module includes one, the selection unit includes a plurality of second switch sub-units, each second switch sub-unit is connected with one energy storage unit and one second positive power supply terminal, each second switch sub-unit is connected in series between the first positive power supply terminal of the corresponding energy storage unit and the corresponding second positive power supply terminal, the first negative power supply terminal of one or more energy storage units is respectively connected with 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 with the corresponding second positive power supply terminal in a conducting state.

[0079] In some embodiments, the charging module includes a plurality of seventh power conversion sub-units and a charging gun, the positive input terminal and the negative input terminal of each seventh power conversion sub-unit are connected with one second positive power supply terminal and one second negative power supply terminal, the positive output terminal and the negative output terminal of each seventh power conversion sub-unit are connected with the positive input terminal and the negative input terminal of the charging gun, and the plurality of seventh power conversion sub-units are configured to convert the first direct current into the fourth direct current for charging output through the charging gun. In this way, the charging gun does not share a negative terminal.

[0080] In some embodiments, the charging module includes a plurality of eighth power conversion sub-units and a charging gun, a positive input end of each eighth power conversion sub-unit is connected with one second positive power supply end, a positive output end of each eighth power conversion sub-unit is connected with a positive input end of the charging gun, a negative input end of the charging gun is connected with the second negative power supply end of the energy storage module, and the plurality of eighth power conversion sub-units are configured to convert the first direct current into fourth direct current for charging output through the charging gun. In this way, the charging gun is shared, and the cost can be reduced.

[0081] In some embodiments, the input module includes a ninth power conversion sub-unit connected with one or more energy storage units and configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply. In this way, charging of the energy storage units is realized through one power conversion sub-unit.

[0082] In some embodiments, the input module includes a plurality of tenth power conversion sub-units, each connected with one energy storage unit, and the plurality of tenth power conversion sub-units are configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply. In this way, charging of the energy storage units is realized through a plurality of power conversion sub-units.

[0083] In some embodiments, in the case that the plurality of charging devices share one direct current bus and the input module of the charging device includes an input interface, the system further includes:

[0084] a first transformer, a primary winding of the first transformer being connected with the alternating current grid and being configured to convert the second alternating current provided by the alternating current grid into the first alternating current;

[0085] a first AC-DC conversion module, the first AC-DC conversion module being connected with the secondary winding of the first transformer and the direct current bus respectively and being configured to convert the first alternating current into third direct current;

[0086] wherein the second positive power supply end and the second negative power supply end of the energy storage module of the plurality of charging devices are connected with the direct current bus. In this way, the direct current bus of the plurality of charging devices is realized.

[0087] In some embodiments, in the case that the plurality of charging devices share one direct current bus and the input module of the charging device includes a second power conversion sub-unit, the system further includes:

[0088] a first transformer, a primary winding of the first transformer being connected with the alternating current grid, the second power conversion sub-unit being connected with the secondary winding of the first transformer and the direct current bus respectively, and the first transformer being configured to convert the second alternating current provided by the alternating current grid into the first alternating current;

[0089] The second positive power supply end and the second negative power supply end of the energy storage module in the plurality of charging devices are connected with the DC bus. In this way, the plurality of charging devices share the DC bus.

[0090] In some embodiments, when the plurality of charging devices share an AC bus and the input module of the charging device includes the ninth power conversion subunit or the plurality of tenth power conversion subunits, the system further includes:

[0091] The primary winding of the second transformer is connected with the AC power grid, and the secondary winding of the second transformer is connected with the AC bus, and is configured to convert the second AC power provided by the AC power grid into the first AC power;

[0092] The ninth power conversion subunit or the plurality of tenth power conversion subunits of the input module in the plurality of charging devices are connected with the AC bus. In this way, the plurality of charging devices share the AC bus.

[0093] 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 with the wireless communication module to interact with external equipment through the wireless communication module.

[0094] In the second aspect, the application provides a charging pile including the charging device.

[0095] The above description is only a summary of the technical solutions of the application. In order to enable one skilled in the art to better understand the technical means of the application, the application can be implemented according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the application to be more obvious and easy to understand, the following specific embodiments of the application are described. BRIEF DESCRIPTION OF DRAWINGS

[0096] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of illustrating the preferred embodiments and are not considered limiting the application. Moreover, the same reference numbers are used to represent the same components throughout the drawings. In the drawings:

[0097] Figure 1 Structure schematic diagram of the charging device with the energy storage unit in series for an embodiment of the application.

[0098] Figure 2 Structure schematic diagram of the charging device with the input module for an embodiment of the application.

[0099] Figure 3 Structure schematic diagram of the charging device with the energy storage unit in parallel for an embodiment of the application.

[0100] Figure 4aThis is a schematic diagram of the structure of a charging device for an energy storage unit including a battery sub-unit, according to an embodiment of this application.

[0101] Figure 4b This is a schematic diagram of the structure of a charging device for an energy storage unit including a battery sub-unit and a first power conversion sub-unit, according to an embodiment of this application.

[0102] Figure 4c This is a schematic diagram of the structure of a charging device for an energy storage unit including a battery subunit and a first switch subunit, according to an embodiment of this application.

[0103] Figure 4d This is a schematic diagram of the structure of a charging device for an energy storage unit comprising a battery subunit, a first power conversion subunit, and a first switch subunit, according to one embodiment of this application.

[0104] Figure 5a This is a schematic diagram of the structure of a charging device including an input interface, which is an embodiment of the present application.

[0105] Figure 5b This is a schematic diagram of a charging device whose input module includes a second power conversion subunit, according to one embodiment of this application.

[0106] Figure 6a This is a schematic diagram of the structure of a charging device with a non-common negative charging gun according to an embodiment of this application.

[0107] Figure 6b This is a schematic diagram of the structure of a charging device for a charging gun according to an embodiment of this application.

[0108] Figure 7 This is a schematic diagram of a charging device with a selection unit according to an embodiment of this application.

[0109] Figure 8 for Figure 7 The diagram shows a schematic of a charging device with a second positive power supply terminal.

[0110] Figure 9a for Figure 8 The diagram shows a charging device with a second positive power supply terminal and a non-common negative charging gun.

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

[0112] Figure 10 for Figure 7 The diagram shows a charging device with multiple second positive power terminals.

[0113] Figure 11a forFigure 10 Structure diagram of the charging device with multiple second positive power supply terminals and the charging gun not sharing a negative terminal.

[0114] Figure 11b For Figure 10 Structure diagram of the charging device with multiple second positive power supply terminals and the charging gun sharing a negative terminal.

[0115] Figure 12a For Figure 7 Structure diagram of the charging device with a selection unit and the input module including a ninth power conversion subunit.

[0116] Figure 12b For Figure 7 Structure diagram of the charging device with a selection unit and the input module including multiple tenth power conversion subunits.

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

[0118] Figure 14 Structure diagram of the charging device with energy storage units in series, each energy storage unit including a bidirectional DCDC subunit, and the charging gun not sharing a negative terminal according to an embodiment of the present application.

[0119] Figure 15 Structure diagram of the charging device with energy storage units in series, each energy storage unit including a bidirectional DCDC subunit, and the charging gun sharing a negative terminal according to an embodiment of the present application.

[0120] Figure 16 Structure diagram of the charging device with energy storage units in parallel, each energy storage unit including a bidirectional DCDC subunit, and the charging gun not sharing a negative terminal according to an embodiment of the present application.

[0121] Figure 17 Structure diagram of the charging device with energy storage units in parallel, each energy storage unit including a bidirectional DCDC subunit, and the charging gun sharing a negative terminal according to an embodiment of the present application.

[0122] Figure 18 Structure diagram of the charging device with energy storage units in series, part of the energy storage units including bidirectional DCDC subunits, and the charging gun not sharing a negative terminal according to an embodiment of the present application.

[0123] Figure 19 Structure diagram of the charging device with energy storage units in series, part of the energy storage units including bidirectional DCDC subunits, and the charging gun sharing a negative terminal according to an embodiment of the present application.

[0124] Figure 20Structure diagram of a charging device with parallel energy storage units, each energy storage unit comprising a first switch subunit and the charging gun not sharing a negative pole, according to an embodiment of the present application.

[0125] Figure 21 Structure diagram of a charging device with parallel energy storage units and bidirectional ACDC subunits to generate three-phase power and the charging gun not sharing a negative pole, according to an embodiment of the present application.

[0126] Figure 22 Structure diagram of a charging device with parallel energy storage units and bidirectional ACDC subunits to generate three-phase power and the charging gun sharing a negative pole, according to an embodiment of the present application.

[0127] Figure 23 Structure diagram of a single cell, according to some embodiments of the present application.

[0128] Figure 24 Exploded diagram of a single cell, according to some embodiments of the present application.

[0129] Figure 25 Structure diagram of a battery module, according to some embodiments of the present application.

[0130] Figure 26 Structure diagram of a battery pack, according to some embodiments of the present application.

[0131] Figure 27 Structure diagram of an electrical device, according to some embodiments of the present application.

[0132] Figure 28 Structure diagram of a charging pile, according to an embodiment of the present application.

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

[0134] Figure 30 Structure diagram of a charging and storage system with multiple charging devices sharing a DC bus, according to an embodiment of the present application.

[0135] Figure 31 Structure diagram of a charging and storage system with multiple charging devices sharing a DC bus, according to another embodiment of the present application.

[0136] Figure 32 Structure diagram of a charging and storage system with multiple charging devices sharing an AC bus, according to an embodiment of the present application.

[0137] Legend of reference signs is as follows:

[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 supply; 220, second external power supply; 131, second power conversion subunit; 132, ninth power conversion subunit;

[0139] 1, electric device; 2, battery pack; 3, controller; 4, motor; 5, box body; 5a, first box body part; 5b, second box body part; 5c, containing space; 6, battery module;

[0140] 7, single battery cell;

[0141] 10, electrode assembly; 11, first tab; 13, second tab; 12, main body part;

[0142] 20, outer shell; 21, shell; 22, end cover;

[0143] 31, first electrode terminal; 32, second electrode terminal. DETAILED DESCRIPTION

[0144] The embodiments of the technical scheme of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0145] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments of the present application, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0146] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0147] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be incorporated into any other embodiment.

[0148] In the description of the embodiments of the application, the term“and / or” only means an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character“ / ” herein generally means that the front and rear associated objects are in an“or” relationship.

[0149] In the description of the embodiments of the application, the term“a plurality of” means two or more (including two), and similarly, “a plurality of groups” means two or more groups (including two groups), and “a plurality of pieces” means two or more pieces (including two pieces).

[0150] In the description of the embodiments of the application, the technical terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the application.

[0151] In the description of the embodiments of the application, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connection”,“connection”,“fixing” and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the application can be understood according to the specific circumstances.

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

[0153] However, the fast charging / super charging charging pile in the related art needs to be additionally configured with a transformer or the transformer needs to be expanded, which is not conducive to the rapid access of the fast charging / super charging charging pile and increases the cost. For example, the input end of the transformer is connected with the alternating current power grid, and the output end of the transformer is connected with the charging pile. When the charging pile is a fast charging / super charging charging pile, the transformer needs to be expanded or a new transformer needs to be added between the original transformer and the fast charging / super charging charging pile. However, since the transformer needs to be expanded or a new transformer needs to be added, it is not conducive to the rapid access of the fast charging / super charging charging pile and increases the cost.

[0154] Based on this, the application provides a charging and storing system. Without the need of additionally configuring a transformer or expanding the transformer, by configuring an energy storing unit inside the charging device, not only the fast charging, such as fast charging / super charging, of the charging device can be realized, but also the cost caused by adding a new transformer or expanding the transformer can be reduced.

[0155] The charging device disclosed in the embodiments of the application can be used to charge the equipment, such as electric vehicles, electric ships and electric tools, which need fast charging / super charging, and can also be used to charge the equipment, such as electric vehicles, electric ships and electric tools, which do not need fast charging / super charging. That is, the charging device disclosed in the embodiments of the application can realize the charging of the electric equipment according to high power and low power, and has a wide range of applications.

[0156] The charging and storing system of the application will be described below in combination with specific embodiments.

[0157] Figure 1 FIG. 1 is a structural schematic diagram of a charging device 100 according to an embodiment of the application.

[0158] Referring to FIG. 1, Figure 1 The charging device 100 can include an energy storing module 110 and a charging module 120.

[0159] The energy storing module 110 includes one or more energy storing units, which are energy storing unit A1,..., energy storing unit An (n is a positive integer). n-1 and energy storing unit An (n is a positive integer). n Each energy storing unit has a first positive power supply end (+) and a first negative power supply end (-), and the one or more energy storing units are connected with the second positive power supply end (+) and the second negative power supply end (-) of the energy storing module 110 through the first positive power supply end and the first negative power supply end. The energy storing module 110 is configured to provide first direct current. As an example, the energy storing unit can be an electric box.

[0160] The charging module 120 is connected with the second positive power supply end and the second negative power supply end of the energy storage module 110, and 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 small power charging, the energy storage units can be set to one or a small number of several, which can meet the small power charging application scenario at this time. When the charging device 100 is used for large power charging, the energy storage units can be set to multiple, which can meet the large power and small 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 perform large power or small power charging. Due to the modularity of the energy storage unit, the energy storage unit can be freely increased or decreased, which can realize rapid access and large power charging without the need to increase or expand the transformer.

[0162] When the energy storage unit is one, the first positive power supply end of the energy storage unit is connected with the second positive power supply end of the energy storage module 110, and the first negative power supply end of the energy storage unit is connected with the second negative power supply end of the energy storage module 110. The second positive power supply end and the second negative power supply end of the energy storage module 110 are also connected with the charging module 120. When charging, the energy storage module 110 provides the first direct current through the energy storage unit, and the charging module 120 obtains the target direct current by converting the first direct current to charge the device to be charged. At this time, the charging device 100 can meet the small power charging application scenario. It should be noted that the related parameters of the energy storage unit and the charging module 120 can be set based on actual conditions, and the charging demand can be met by reasonable parameter configuration.

[0163] When the energy storage unit is multiple, multiple energy storage units can be connected in series, parallel or series-parallel mode, and connected with the charging module 120 through the second positive power supply end and the second negative power supply end of the energy storage module 110. For example, in the case of multiple energy storage units, the energy storage units can be connected in series, and the series connection of the energy storage units is connected with the charging module 120 through the second positive power supply end and the second negative power supply end of the energy storage module 110. Figure 1In the specific embodiment, the energy storage unit A1, the energy storage unit An-1 and the energy storage unit An are connected in series between the second positive power supply end and the second negative power supply end of the energy storage module 110 through the first positive power supply end and the first negative power supply end of each energy storage unit, and the second positive power supply end and the second negative power supply end of the energy storage module 110 are also connected with the charging module 120. When charging, when high-power charging is needed, the energy storage module 110 provides first direct current through the plurality of energy storage units, which can have high power, and then the charging module 120 converts the first direct current to obtain target direct current to charge the device to be charged, which has high power, so as to meet the high-power charging application scenario; when low-power charging is needed, the first direct current can have low power, and the target direct current has low power, so as to meet the low-power charging application scenario. It should be noted that the related parameters of the energy storage unit and the charging module 120 can be set based on the actual situation, and the charging demand can be met through reasonable parameter configuration. When there are a plurality of energy storage units, the power of the energy storage module is the sum of the powers of the plurality of energy storage units.

[0164] For example, the maximum charging output power of the charging module 120 is greater than or equal to 350 kW, that is, the maximum charging output power of the charging device 100 is greater than or equal to 350 kW. For example, by selecting a reasonable number of energy storage units, the maximum charging output power of the charging module 120 can reach 350 kW, 360 kW, 500 kW, 800 kW and 900 kW, etc. It should be noted that the charging output power here refers to the maximum charging output power, which can be downward compatible in actual charging. For example, when the maximum charging output power is 360 kW, it means that the charging device 100 can output a charging output power of 0-360 kW to meet different charging demands.

[0165] 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, for example, a multiple relationship of 1.1-1.2, so the rated charging output power of the charging module 120 can be greater than or equal to 290 kW, that is, the rated charging output power of the charging device 100 is greater than or equal to 290 kW.

[0166] In actual application, the maximum charging output power of the charging module 120 can be limited, the rated charging output power can be limited, or both can be limited.

[0167] In the above embodiments, by configuring the modular energy storage units inside the charging device, or by arranging the modular energy storage units and the modular charging units outside the charging device, i.e., arranging the energy storage modules and the charging modules outside the charging device, the energy storage units and the charging units can be freely added or removed. When high-power charging is needed, the free and fast access of the energy storage units can not only realize high-power charging, such as fast charging / ultra-fast charging, but also can reduce the cost of transformers without the need of additional transformers or transformer expansion.

[0168] In some embodiments, referring to Figure 2 The charging device 100 further comprises an input module 130 adapted to provide charging energy for each energy storage unit.

[0169] In an example, the input module 130 can be an AC-DC conversion unit.

[0170] Taking the input module 130 as an AC-DC conversion unit as an example, the input module 130 can be adapted to provide charging energy for the energy storage units. In different power consumption environments, whether in old urban areas with relatively tight power supply or in remote areas sensitive to infrastructure construction cost, the charging device can adjust the power supply parameters of the energy storage modules 110 by the input module 130, so as to realize the function of fast charging without relying on external complex power supply upgrade, and enhance the applicability and flexibility of the charging device in various scenarios.

[0171] Therefore, the power grid can charge the energy storage units 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 for charging each energy storage unit in the energy storage module 110, and is used for small-power charging during charging. For example, 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, 85 kilowatts, etc. It should be noted that the output power here refers to the maximum output power, which can be downward compatible during actual charging. For example, when the maximum output power is 150 kilowatts, it means that the output power of 0-150 kilowatts can be used to charge each energy storage unit in the energy storage module 110.

[0174] In this example, the input module 130 is for small power output, while the charging module 120 can be for large power output, so the entire charging device 100 can achieve large power output under small 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 due to the capacity of the transformer, such as a maximum output power of 150 kW. At this time, the small power is used to charge each energy storage unit in the energy storage module 110, but when the energy storage module 110 discharges externally to charge the device to be charged, based on multiple energy storage units, large power charging can be achieved, such as a maximum charging output power of 360 kW of the charging module 120. In this way, large power output under small power input is achieved, so that the charging device can meet the demand for large power charging without additional transformers or transformer expansion. Those skilled in the art can understand that the power grid generally refers to a system that can provide power. As an example, the power grid can be a municipal power source.

[0175] It can be understood that the maximum output power of the input module 130 and the rated output power satisfy a certain multiple relationship, for example, a multiple relationship of 1.1-1.2, so the rated output power of the input module 130 can be less than or equal to 125 kW.

[0176] In actual application, the maximum output power of the input module 130 can be limited, the rated output power can be limited, or both can be limited.

[0177] In the above embodiment, by configuring modular energy storage units inside the charging device 100, the maximum output power and / or rated power of the input module 130 is limited within the above range, so that the charging device 100 can be flexibly connected to the power network. Specifically, since the output power of most public power grids or commercial power interfaces has certain limitations, the power setting of the input module 130 can successfully obtain charging energy from the conventional power environment without modifying the existing power supply line, improving the accessibility of the charging device 100 in various power consumption scenarios to facilitate the installation of the charging device 100. In addition, the charging device 100 can achieve large power charging under small power input, so that the charging device 100 can meet the demand for large power charging without additional transformers or transformer expansion. During the peak power consumption period, when multiple power consumption devices are running at the same time, the energy storage module supplies power to multiple power consumption devices, and the input module 130 charges the energy storage unit at a lower power, which can effectively reduce the impact of the charging device 100 on the power grid during charging, and help maintain the stability of the power grid.

[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, i.e., 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, 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 can be greater than 2, greater than 2.3, greater than 3, greater than 4, greater than 8, or greater than 12.5, etc., so as to realize high-power output under 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 kW, then the maximum charging output power of the charging module 120 is greater than or equal to 500 kW.

[0180] Meanwhile, the ratio between the maximum charging output power of the charging module 120 and 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 kW, then the maximum charging output power of the charging module 120 is less than or equal to 900 kW.

[0181] It should be noted that when the above ratio is set, the minimum ratio is less than or equal to the maximum ratio, for example, the ratio between the maximum charging output power of the charging module 120 and the maximum output power of the input module 130 is greater than 2 and less than or equal to 15, or greater than 1 and less than or equal to 6, or greater than 6 and less than or equal to 12.5, etc., which is selected and set 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, high performance and cost ratio can be achieved under the condition of high-power output under low-power input.

[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, for example, a multiple relationship of 1.1-1.2, and the maximum output power of the input module 130 and the rated output power satisfy a certain multiple relationship, for example, a multiple relationship of 1.1-1.2, so 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 application, 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, and 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 limited, or both can be limited.

[0185] In the above embodiment, by limiting the ratio between the maximum charging output power of the charging module and the maximum output power of the input module, and / or limiting the ratio between the rated charging output power of the charging module and the rated output power of the input module, on the one hand, the current impact, overheating and other problems caused by the charging module 120 due to instantaneous excessive power input can be reduced. On the other hand, the input module 130 can charge the energy storage module 110 with small power, and the energy storage module can output to the charging module 120 with controllable large power, realizing small power input to the energy storage module 110 and large power output of the charging module 120. In addition, the energy storage module 110 can flexibly adjust the output power according to the amount of electricity stored and the power demand of the power consumption equipment, so that the charging device 100 can reasonably distribute the electric energy, reduce unnecessary energy consumption, improve the performance-price ratio of the charging device 100, and make the charging device 100 run smoothly when the small power input is large power output.

[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 is in the range of 1-4.

[0187] Specifically, the rated energy of the battery subunit refers to the energy capacity specified at the design of the battery subunit, which represents the maximum energy value that the battery subunit can store or output under normal working conditions, and the unit is kilowatt-hour. The rated output power of the input module 130 is greater than or equal to the rated energy of the battery subunit / n1 / 100%, where n1 can be 1, 1.4, 2, 3, and 4, etc. By specifying that the rated output power of the input module is greater than the rated energy of the battery subunit divided by the coefficient n1, when the input power of the input module 130 is small, the rated energy of the battery subunit is small, so that the input power and the rated energy of the battery subunit are matched, and the input module 130 will not charge the battery subunit too slowly, affecting the use of the energy storage unit. At the same time, the small rated energy of the battery subunit also means that the battery subunit has a small volume, so that the energy storage unit occupies a small area and is easy to install. Further, the small volume of the energy storage unit realizes small power input and large power output, and improves the 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 n2 ranges from 94% to 99%, and n3 ranges from 4 to 6.

[0189] That is, the rated energy of the battery subunit is greater than or equal to the rated charging output power of the charging module 120 / (n2*n3)*100%, where n2 can be 94%, 96%, 98.5%, and 99%, etc., and n3 can be 4, 5, 5.5, and 6, etc. In this way, the charging performance is guaranteed while the reliability of the charging device 100 is taken into account. When the rated energy of the battery subunit and the rated charging output power of the charging module 120 are matched, the battery subunit can stably provide energy for the charging module 120 during the charging process, reducing the instability or interruption of the charging power caused by insufficient energy supply. Taking n2=94% and n3=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, which enables the charging device 100 to work stably for a long time during high-power charging, reduces the probability of failure, and reduces maintenance costs, thereby prolonging the service life of the charging device 100 and improving the cost performance.

[0190] 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 power of the battery subunit is less than or equal to 1 / 3, and / or the volumetric energy density of the battery subunit is greater than 380 watt-hours per liter.

[0191] That is, the ratio of the rated energy of the battery subunit 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 kW, the rated energy of the battery subunit is 58 kWh. In this way, the cost performance of the entire charging device can be improved.

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

[0193] When the charging device 100 has a high-power (the maximum charging output power of the charging module is greater than or equal to 350 kW) output, the ratio of the rated energy of the battery subunit to the rated power of the battery subunit is less than or equal to 1 / 3, and / or the volumetric energy density of the battery subunit is greater than 380 Wh / L, so that the rated energy of the battery subunit matches the rated power of the battery subunit, reduces the grid fluctuation caused by the need for grid power supply due to insufficient rated energy of the battery subunit caused by high-power output, and is beneficial to improve the reliability and stability of the charging device 100. When the charging device 100 has a high-power output, it can work stably and continuously, reduce the probability of failure, reduce maintenance costs, thereby prolonging the service life of the charging device 100 and improving the cost performance.

[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 4C, for example, greater than or equal to 5C, 6C, 7C, or 8C, etc. In this way, high-power output can be provided.

[0195] It should be noted that the above parameters can be stacked. For example, when the maximum charging output power of the charging module 120 is greater than or equal to 350 kW, the maximum output power of the battery subunit is greater than or equal to 350 kW, the rated power of the battery subunit is greater than or equal to 350 kW, the rated energy of the battery subunit is greater than or equal to 58 kWh, and the maximum discharge rate of the battery subunit is greater than or equal to 4C, the maximum output power of the input module 130 can be less than or equal to 150 kW.

[0196] It should be noted that the above-mentioned related parameters of the battery sub-unit are applicable to the energy storage unit and / or the energy storage module in some cases, that is, the above-mentioned parameters are applicable to the energy storage unit, the energy storage module and the battery sub-unit in some cases. For example, when the energy storage unit only includes a battery sub-unit, the related parameters of the battery sub-unit are the related parameters of the energy storage unit, and further, when the energy storage module 110 includes an energy storage unit, the related parameters of the battery sub-unit are the related parameters of the energy storage module 110; and the like.

[0197] It should be noted that the energy storage unit can include one or more battery sub-units, and the plurality of battery sub-units can be connected in series, in parallel or in series-parallel. Each battery sub-unit can be a single cell or a plurality of single cells connected in series, in parallel or in series-parallel. For example, the single cell can include 10-100, and 2-6 battery sub-units can be obtained by combining the single cells, and the 2-6 battery sub-units can be connected in series and / or in parallel, so that the energy storage unit can reach 80-150 kilowatt hours through the 2-6 battery sub-units. For example, 80 kilowatt hours can be obtained by combining 2 single cells; for example, 150 kilowatt hours can be obtained by combining 100 single cells; for example, 90 kilowatt hours can be obtained by combining 80 single cells; and the like.

[0198] In the above-mentioned embodiments, by limiting the proportional relationship of the rated energy and the rated power of the battery sub-unit, 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 performance.

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

[0200] Specifically, when the energy storage unit is one, the first positive power supply end of the energy storage unit is connected to the second positive power supply end of the energy storage module 110, and the first negative power supply end of the energy storage unit is connected to the second negative power supply end of the energy storage module 110, and the first direct current is provided through the energy storage unit.

[0201] When the energy storage unit is a plurality, the plurality of energy storage units can be connected in series, in parallel or in series-parallel. For example, referring to Figure 1 , the plurality of energy storage units are connected in series between the second positive power supply end and the second negative power supply end of the energy storage module 110 through the first positive power supply end and the first negative power supply end of the energy storage units; for example, referring to Figure 3For example, the plurality of energy storage units are connected in series between the second positive power supply end and the second negative power supply end of the energy storage module 110. For another example, the plurality of energy storage units are connected in parallel between the second positive power supply end and the second negative power supply end of the energy storage module 110. For yet another example, the plurality of energy storage units are connected in series first and then in parallel, or connected in parallel first and then in series between the second positive power supply end and the second negative power supply end of the energy storage module 110. The first direct current is provided by the plurality of energy storage units connected in series, in parallel, or in series and in parallel. The connection mode can be selected based on actual conditions.

[0202] In the above embodiments, the plurality of energy storage units can be connected in series, in parallel, or in series and in parallel, and free access of the energy storage units can be achieved to meet different charging power requirements.

[0203] In some embodiments, referring to Figures 4a-4d each energy storage unit includes a battery subunit, and each energy storage unit is configured to provide the second direct current based on the electrical energy of the battery subunit.

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

[0205] In some embodiments, referring to Figure 4b at least part of the one or more energy storage units further includes a first power conversion subunit, the first power conversion subunit is connected to the first positive power supply end and the first negative power supply end of the corresponding battery subunit and energy storage unit, respectively, and is configured to convert the electrical energy of the battery subunit into the second direct current; wherein, in the case that the energy storage unit does not include the first power conversion subunit, the battery subunit is directly connected to the first positive power supply end and the first negative power supply end of the corresponding energy storage unit to provide the second direct current.

[0206] Specifically, when the energy storage unit is one, the energy storage unit further includes the first power conversion subunit to convert the electrical energy of the battery subunit into the second direct current.

[0207] When the energy storage unit is a plurality, a first power conversion subunit can be provided in each of the plurality of energy storage units, or a first power conversion subunit can be provided in part of the plurality of energy storage units. For example, in Figure 4bIn the above, energy storage unit A1 includes battery subunit BAT1 and first power conversion subunit B1. First power conversion subunit B1 is connected to the first positive power supply terminal and the first negative power supply terminal of both battery subunit BAT1 and energy storage unit A1, respectively. Through first power conversion subunit B1, the electrical energy of battery subunit BAT1 is converted into a second direct current;...; Energy storage unit A n-1 Including battery sub-unit BAT n-1 and the first power conversion subunit B n-1 The first power conversion subunit Bn-1 is connected to 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 through the first power conversion subunit B. n-1 BAT battery sub-cells n-1 The electrical energy is converted into a second direct current; energy storage unit A n Including battery sub-unit BAT n Battery sub-unit BAT n Directly connected to energy storage unit A n The first positive power supply terminal and the first negative power supply terminal are connected to provide a second DC power.

[0208] In some embodiments, when the battery sub-unit is discharging externally, the maximum output power of the first power conversion sub-unit is greater than or equal to 350 kW, and / or the rated output power is greater than or equal to 310 kW. When the battery sub-unit is charging, the ratio of the maximum output power of the input module 130 to the maximum output power of the first power conversion sub-unit is not greater than 1:4, and / or the ratio of the rated output power of the input module 130 to the rated output power of the first power conversion sub-unit is not greater than 1:4.

[0209] In the above embodiments, some or all of the multiple energy storage units can be equipped with a first power conversion subunit. The first power conversion subunit converts the electrical energy of the battery subunit to provide a second DC power, which can improve the charging flexibility. At the same time, by partially setting the first power conversion subunit, the cost can be reduced while meeting the charging requirements. Moreover, this method can realize access with and without the first power conversion subunit, making it highly applicable.

[0210] In some embodiments, refer to Figure 4c, at least part of the one or more energy storage units further comprises a first switch subunit, the first switch subunit is connected with the corresponding battery subunit and the first positive power supply end and the first negative power supply end of the energy storage unit respectively, and is configured to connect the corresponding battery subunit with the first positive power supply end and the first negative power supply end of the energy storage unit to provide the second direct current when the first switch subunit is turned on; wherein, when the energy storage unit does not comprise the first switch subunit, the battery subunit is directly connected with the first positive power supply end and the first negative power supply end of the corresponding energy storage unit to provide the second direct current.

[0211] Specifically, when the energy storage unit is one, the energy storage unit further comprises a first switch subunit, when the first switch subunit is turned on, the battery subunit is connected with the first positive power supply end and the first negative power supply end of the energy storage unit to provide the second direct current; in abnormal conditions, such as abnormality of the battery subunit or the charging module 120, the first switch subunit is turned off 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 demand, the first switch subunit is turned off to make the battery subunit stop providing the second direct current.

[0212] When the energy storage unit is multiple, a first switch subunit can be arranged in each of the multiple energy storage units, or a first switch subunit can be arranged in part of the multiple energy storage units. For example, in the energy storage unit A1, the energy storage unit A2, the energy storage unit A3, and the energy storage unit A4, the energy storage unit A1 comprises the battery subunit BAT1 and the first switch subunit C1, the first switch subunit C1 is connected with the battery subunit BAT1 and the first positive power supply end and the first negative power supply end of the energy storage unit A1 respectively, and the first switch subunit C1 controls the on-off of the battery subunit BAT1 and the first positive power supply end and the first negative power supply end of the energy storage unit A1 to selectively provide the second direct current; the energy storage unit A2 comprises the battery subunit BAT2, and the battery subunit BAT2 is directly connected with the first positive power supply end and the first negative power supply end of the energy storage unit A2 to provide the second direct current; the energy storage unit A3 comprises the battery subunit BAT3 and the first switch subunit C3, the first switch subunit C3 is connected with the battery subunit BAT3 and the first positive power supply end and the first negative power supply end of the energy storage unit A3 respectively, and the first switch subunit C3 controls the on-off of the battery subunit BAT3 and the first positive power supply end and the first negative power supply end of the energy storage unit A3 to selectively provide the second direct current; the energy storage unit A4 comprises the battery subunit BAT4 and the first switch subunit C4, the first switch subunit C4 is connected with the battery subunit BAT4 and the first positive power supply end and the first negative power supply end of the energy storage unit A4 respectively, and the first switch subunit C4 controls the on-off of the battery subunit BAT4 and the first positive power supply end and the first negative power supply end of the energy storage unit A4 to selectively provide the second direct current. Figure 4c n-1 n-1 n-1 n-1 n-1 n-1 n-1 n-1 n-1 n n n n ​​​​​​​​​​​​​The first positive power terminal and the first negative power terminal of the first energy storage unit are connected to the first positive power terminal and the first negative power terminal of the battery subunit, so as to provide the second direct current.

[0213] In the above embodiment, part or all of the plurality of energy storage units can be provided with the first switch subunit, and the battery subunit selectively provides the second direct current through the first switch subunit, so as to improve the flexibility of charging and protection in abnormal conditions.

[0214] In some embodiments, referring to Figure 4d , at least part of the one or more energy storage units further comprises a first power conversion subunit and a first switch subunit, the first power conversion subunit and the first switch subunit are connected in series between the first positive power terminal and the first negative power terminal of the corresponding battery subunit and the energy storage unit, and the first power conversion subunit is configured to convert the electrical energy of the battery subunit into the second direct current when the corresponding first switch subunit is turned on; wherein, in the case that the energy storage unit does not comprise the first power conversion subunit and the first switch subunit, the battery subunit is directly connected to the first positive power terminal and the first negative power terminal of the corresponding energy storage unit to provide the second direct current.

[0215] Specifically, when the energy storage unit is one, the energy storage unit further comprises a first power conversion subunit and a first switch subunit, and the first power conversion subunit converts the electrical energy of the battery subunit into the second direct current when the first switch subunit is turned on; in abnormal conditions, such as abnormality of the battery subunit or the charging module 120, the first switch subunit is turned off, 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 demand, the first switch subunit is turned off, and the first power conversion subunit stops working to make the battery subunit stop providing the second direct current.

[0216] When the energy storage unit is a plurality, a first switch subunit and a first power conversion subunit can be provided in each of the plurality of energy storage units, or a first switch subunit and a first power conversion subunit can be provided in part of the plurality of energy storage units. For example, Figure 4d , the energy storage unit A1 comprises 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 first positive power terminal and the first negative power terminal of the battery subunit BAT1 and the energy storage unit A1, and the first power conversion subunit B1 converts the electrical energy of the battery subunit BAT1 into the second direct current when the first switch subunit C1 is turned on;...; the energy storage unit A n-1 comprises a battery subunit BAT n-1 , a first switch subunit C n-1 and a first power conversion subunit Bn-1 , the first switch subunit C n-1 and the first power conversion subunit B n-1 is connected in series with the battery subunit BAT n-1 and the energy storage unit A n-1 between the first positive power supply end and the first negative power supply end of the energy storage unit A n-1 , in the case of being turned on, the first power conversion subunit B n-1 converts the electric energy of the battery subunit BAT n-1 into the second direct current; the energy storage unit A n includes the battery subunit BAT n , the battery subunit BAT n is directly connected with the first positive power supply end and the first negative power supply end of the energy storage unit A n to provide the second direct current.

[0217] It should be noted that in some embodiments, a part of the energy storage unit can also include the first switch subunit, and the other part includes the first power conversion subunit, which is not limited here.

[0218] In the above embodiment, part or all of the plurality of energy storage units can be provided with the first switch subunit and the first power conversion subunit, so as to improve the flexibility of charging and the protection ability in abnormal conditions.

[0219] In some embodiments, the first power conversion subunit is a bidirectional DCDC subunit, and the charging and discharging of the battery subunit are realized through the bidirectional DCDC subunit. The bidirectional DCDC subunit includes but is not limited to a BUCK-BOOST circuit and the like, which is not limited here.

[0220] In some embodiments, referring to Figure 5a , the input module 130 includes an input interface (X, Y) connected with the second positive power supply end and the second negative power supply end of the energy storage module 110, and is configured to provide charging energy for each energy storage unit based on the third direct current provided by the first external power supply 210.

[0221] Specifically, the first external power supply 210 is used to generate the third direct current, and transmit it to the energy storage module 110 through the input interface to charge each energy storage unit in the energy storage module 110. For example, the first external power supply 210 can include a first transformer and a first AC / DC conversion module. The primary winding of the first transformer is connected with the AC power grid to convert the second alternating current provided by the AC power grid into the first alternating current. The first AC / DC conversion module is connected with the secondary winding of the first transformer and the input interface respectively to convert the first alternating current into the third direct current and transmit it to the energy storage module 110 through 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, not only charging of the energy storage module 110 can be implemented, but also electric energy of the energy storage module 110 can be fed to 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 supply 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, referring to Figure 5b The input module 130 includes a second power conversion subunit 131 connected to the second positive power supply end and the second negative power supply end of the energy storage module 110, and configured to provide charging energy for each energy storage unit based on the first AC power provided by the second external power supply 220.

[0226] Specifically, the second external power supply 220 is configured to generate the first AC power and provide the first AC power to the second power conversion subunit 131 in the input module 130, so as to charge each battery subunit in the energy storage module 110 through the second power conversion subunit 131. For example, the second external power supply 220 can include a first transformer, a primary winding of the first transformer being connected to the AC power grid, and the second power conversion subunit 131 being connected to a 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 power grid into the first AC power, and provides the first AC power to the second power conversion subunit 131. The second power conversion subunit 131 converts the first AC power into the 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, not only charging of the energy storage module 110 can be implemented, but also electric energy of the energy storage module 110 can be fed 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 the rated output power of the input module 130 are also the maximum output power and the rated output power of the second power conversion subunit 131.

[0229] In the above embodiments, when the external power supply provides alternating current, the battery subunit can be charged by the second power conversion subunit.

[0230] In some embodiments, referring 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. For example, the number of charging guns 122 is two, and the maximum charging output power or rated output power of each charging gun 122 can be 500kW, which can simultaneously charge the same electric device, which can be an electric vehicle, and each charging gun 122 can also individually charge different electric devices.

[0232] When the number of charging guns 122 is multiple, multiple charging guns 122 can be connected to the energy storage module 110 through the same charging module conversion unit, and each charging gun 122 can also be individually connected to the energy storage module 110 through a charging module conversion unit. The charging module conversion unit can be a DCDC conversion unit, which can be a unipolar one-way DCDC conversion unit or a unipolar bidirectional DCDC conversion unit, or a bipolar one-way DCDC conversion unit or a bipolar bidirectional DCDC conversion unit.

[0233] The charging module conversion unit can flexibly adjust the voltage, current, and other parameters according to the direct current output by the energy storage module 110 and the requirements of the charging gun 122 connected device (such as an electric vehicle), to achieve efficient charging output. The configuration of at least one charging gun 122 allows the charging device 100 to simultaneously charge one or more electric devices. In a public charging area, such as a parking lot, a charging station, etc., multiple users can simultaneously use different charging guns 122 to charge their electric vehicles, improving the use efficiency and service capacity of the charging device 100, meeting the use requirements in large-scale charging demand scenarios, effectively alleviating the charging queuing and waiting problem, and improving the user experience.

[0234] In some embodiments, referring to Figure 6aThe charging module 120 includes a third power conversion subunit 121 and a charging gun 122. The positive input end and the negative input end of the third power conversion subunit 121 are connected to the second positive power supply end and the second negative power supply end of the energy storage module 110, respectively. The positive output end and the negative output end of the third power conversion subunit 121 are connected to the positive input end and the negative input end of the charging gun 122, respectively. 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, the one or more energy storage units provide the second direct current, so that the energy storage module 110 provides the first direct current, which is converted into the fourth direct current by the third power conversion subunit 121 and provided to the charging gun 122, and then provided to the device to be charged by the charging gun 122, so as to charge the device to be charged.

[0236] In this example, the third power conversion subunit 121 has bipolarity, i.e., has a positive input end and a negative input end. At this time, the positive input end and the negative input end of the third power conversion subunit 121 are directly connected to the second positive power supply end and the second negative power supply end of the energy storage module 110, respectively. The positive output end and the negative output end of the third power conversion subunit 121 are directly connected to the positive input end and the negative input end of the charging gun 122, respectively. The negative input end of the charging gun 122 and the second negative power supply end of the energy storage module 110 are not shared. In this way, it is suitable for the application scenario in which the third power conversion subunit 121 has 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, not only can the device to be charged be charged, but also the electrical energy of the device to be charged can be fed to the energy storage module 110, and can also be fed to the AC power grid in the foregoing example through the input module 130, so as to ultimately realize the free conversion of electrical energy among the grid, the charging, and the storage.

[0238] In some embodiments, referring to Figure 6b The charging module 120 includes a fourth power conversion subunit 123 and the charging gun 122. The positive input end of the fourth power conversion subunit 123 is connected to the second positive power supply end of the energy storage module 110. The positive output end of the fourth power conversion subunit 123 is connected to the positive input end of the charging gun 122. The negative input end of the charging gun 122 is connected to the second negative power supply end 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, the one or more energy storage units provide the second direct current, so that the energy storage module 110 provides the first direct current, which is converted into the fourth direct current by the fourth power conversion subunit 123 and provided to the charging gun 122, and then provided to the device to be charged by the charging gun 122, so as to charge the device to be charged.

[0240] In this example, the fourth power conversion subunit 123 has a single polarity, that is, only has a positive input end. At this time, the positive input end of the fourth power conversion subunit 123 is directly connected with the second positive power supply end of the energy storage module 110, the positive output end of the fourth power conversion subunit 123 is directly connected with the positive input end of the charging gun 122, and the negative input end of the charging gun 122 is directly connected with the second negative power supply end of the energy storage module 110, that is, the negative input end of the charging gun 122 and the second negative power supply end of the energy storage module 110 are shared. In this way, it is suitable for the application scenario that the fourth power conversion subunit 123 has a single polarity, and the cost is low.

[0241] The fourth power conversion subunit 123 can be a single-polarity one-way DCDC subunit or a single-polarity bidirectional DCDC subunit. When the fourth power conversion subunit 123 is a single-polarity bidirectional DCDC subunit, not only can the device to be charged be charged, but also the electrical energy of the device to be charged can be fed to the energy storage module 110, and can also be fed to the AC power grid in the foregoing example through the input module 130, so as to finally realize the free conversion of electrical energy among the grid, charging and storage.

[0242] In the above embodiments, by sharing or not sharing the negative input end of the charging gun, different power supply scenarios can be applied, thereby improving the selection range when selecting the circuit structure.

[0243] In some embodiments, referring to Figure 7 The energy storage module 110 further includes a selection unit 111 connected with the one or more energy storage units and configured to select at least one energy storage unit from the one or more energy storage units to be connected with the second positive power supply end and the second negative power supply end of the energy storage module 110, so as to provide the first direct current.

[0244] Specifically, when charging, the selection unit 111 can select one energy storage unit A1 to be connected with the second positive power supply end and the second negative power supply end of the energy storage module 110, so as to provide the first direct current; or, all energy storage units A1,..., energy storage unit A n-1 and energy storage unit A n are connected with the second positive power supply end and the second negative power supply end of the energy storage module 110, so as to provide the first direct current. Then, the charging module 120 performs charging output based on the first direct current.

[0245] In the above embodiment, the energy storage unit is selectively controlled by the selection unit to output, so that the flexibility of charging can be improved, and different charging requirements can be met.

[0246] In some embodiments, referring to Figure 8 , the second positive power supply end and the second negative power supply end of the energy storage module 110 each include one, the selection unit 111 includes a plurality of second switch sub-units, each of which is connected with one energy storage unit, each second switch sub-unit is connected in series between the first positive power supply end of the corresponding energy storage unit and the second positive power supply end of the energy storage module 110, and the first negative power supply end of one or more energy storage units is respectively connected with the second negative power supply end of the energy storage module 110. The second switch sub-unit is configured to connect the first positive power supply end of the corresponding energy storage unit with the second positive power supply end of the energy storage module 110 in the on state.

[0247] Specifically, the selection unit 111 includes a second switch sub-unit K1,..., a second switch sub-unit Kn-1, and a second switch sub-unit Kn, wherein the second switch sub-unit K1 is connected in series between the first positive power supply end of the energy storage unit A1 and the second positive power supply end of the energy storage module 110,..., the second switch sub-unit Kn-1 is connected in series between the first positive power supply end of the energy storage unit A n-1 and the second positive power supply end of the energy storage module 110, and the second switch sub-unit Kn is connected in series between the first positive power supply end of the energy storage unit A n and the second positive power supply end 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 direct current, so that the energy storage module 110 provides the first direct current, and at this time the charging module 120 converts the first direct current into the fourth direct current to charge the device to be charged.

[0248] In the above embodiment, by providing one second positive power supply end and selectively controlling the energy storage unit to provide the second direct current by the selection unit, the flexibility of charging can be improved, and the charging requirements can be met.

[0249] In some embodiments, referring to Figure 9a , the charging module 120 includes a fifth power conversion sub-unit 124 and a charging gun 122, the positive input end and the negative input end of the fifth power conversion sub-unit 124 are connected with the second positive power supply end and the second negative power supply end of the energy storage module 110, respectively, the positive output end and the negative output end of the fifth power conversion sub-unit 124 are connected with the positive input end and the negative input end of the charging gun 122, respectively, and the fifth power conversion sub-unit 124 is configured to convert the first direct current into the fourth direct current for charging output through the charging gun 122.

[0250] It should be noted that, for the connection relationship of the fifth power conversion subunit 124 with the charging gun 122 and the energy storage module 110 and the structure of the fifth power conversion subunit 124, please refer to the foregoing description of the third power conversion subunit 121, and details are not repeated here.

[0251] In some embodiments, referring to Figure 9b , the charging module 120 includes the sixth power conversion subunit 125 and the charging gun 122, the positive input end of the sixth power conversion subunit 125 is connected with the second positive power supply end of the energy storage module 110, the positive output end of the sixth power conversion subunit 125 is connected with the positive input end of the charging gun 122, the negative input end of the charging gun 122 is connected with the second negative power supply end of the energy storage module 110, and the sixth power conversion subunit 125 is configured to convert the first direct current into the fourth direct current for charging output through the charging gun 122.

[0252] It should be noted that, for the connection relationship of the sixth power conversion subunit 125 with the charging gun 122 and the energy storage module 110 and the structure of the sixth power conversion subunit 125, please refer to the foregoing description of the fourth power conversion subunit 123, and details are not repeated here.

[0253] In some embodiments, referring to Figure 10 , the second positive power supply end of the energy storage module 110 includes multiple, the second negative power supply end of the energy storage module 110 includes one, and the selection unit 111 includes multiple second switch subunits, each of which is connected with one energy storage unit and one second positive power supply end, each second switch subunit is connected in series between the first positive power supply end of the corresponding energy storage unit and the corresponding second positive power supply end, and the first negative power supply end of one or more energy storage units is respectively connected with the second negative power supply end of the energy storage module 110, and the second switch subunit is configured to connect the first positive power supply end of the corresponding energy storage unit with the corresponding second positive power supply end in the case of conduction.

[0254] Specifically, the selection unit 111 includes the second switch subunit K1,..., the second switch subunit Kn-1, and the second switch subunit Kn, wherein the second switch subunit K1 is connected in series between the first positive power supply end of the energy storage unit A1 and one second positive power supply end of the energy storage module 110,..., the second switch subunit Kn-1 is connected in series between the first positive power supply end of the energy storage unit A n-1 , and the second switch subunit Kn is connected in series between the first positive power supply end of the energy storage unit A nThe first positive power supply terminal is connected to another second positive power supply terminal of the energy storage module 110. By controlling the on / off state of the second switching subunit, 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. It should be noted that the first DC power here includes multiple second DC powers, and the charging module 120 can selectively convert one or more second DC powers into a fourth DC power.

[0255] In the above embodiments, by setting multiple second positive power supply terminals and selectively controlling the energy storage unit to provide a second DC power through a selection unit, the charging flexibility can be improved and the charging demand can be met.

[0256] In some embodiments, refer to Figure 11a The charging module 120 includes multiple seventh power conversion sub-units and a charging gun 122. The positive and negative input terminals of each seventh power conversion sub-unit are connected to a second positive power supply terminal and a second negative power supply terminal respectively. The positive and negative output terminals of each seventh power conversion sub-unit are connected to the positive and negative input terminals of the charging gun respectively. The multiple seventh power conversion sub-units are configured to convert the first DC power into a fourth DC power for charging output through the charging gun.

[0257] Specifically, the multiple seventh power conversion sub-units are seventh power conversion sub-unit D1, ..., seventh power conversion sub-unit D... n-1 and the seventh power conversion subunit D n In this case, 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 is connected to another second positive power supply terminal, the seventh power conversion subunit D. n The positive input terminal is connected to another second positive power supply terminal, the seventh power conversion subunit D1, ..., the seventh power conversion subunit D n-1 and the seventh power conversion subunit D n The negative input terminals are all connected to the second negative power supply terminal. Seventh power conversion subunit D1, ..., Seventh power conversion subunit D n-1 and the seventh power conversion subunit D n The positive and negative output terminals are connected to the positive and negative input terminals of the charging gun 122, respectively.

[0258] In this example, each seventh power conversion subunit can convert the second DC power of the corresponding energy storage unit into the fifth DC power, and finally multiple seventh power conversion subunits output the fourth DC power.

[0259] The seventh power conversion subunit can be a bipolar unidirectional DC-DC subunit or a bipolar bidirectional DC-DC subunit. When the seventh power conversion subunit is a bipolar bidirectional DC-DC 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 feed it to the AC power grid in the aforementioned example through the input module 130, thus realizing the free conversion of power between the grid, charging and storage.

[0260] In some embodiments, refer to Figure 11b The charging module 120 includes multiple eighth power conversion sub-units and a charging gun 122. The positive input terminal of each eighth power conversion sub-unit is connected to a second positive power supply terminal, the positive output terminal of each eighth power conversion sub-unit 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 sub-units are configured to convert the first DC power into a fourth DC power for charging output through the charging gun 122.

[0261] Specifically, the multiple eighth power conversion sub-units are eighth power conversion sub-unit E1, ..., eighth power conversion sub-unit E n-1 and the eighth power conversion subunit E n In this case, the positive input terminal of the eighth power conversion subunit E1 is connected to a second positive power supply terminal, ..., the eighth power conversion subunit E n-1 The positive input terminal is connected to another second positive power supply terminal, the eighth power conversion subunit E n The positive input terminal is connected to another second positive power supply terminal, the eighth power conversion subunit E1, ..., the eighth power conversion subunit E n-1 and the eighth power conversion subunit E n The positive output terminals of the charging gun 122 are all connected to the positive input terminal of the charging gun 122, and the negative input terminal of the charging gun 122 is connected to the second negative power supply terminal of the energy storage module 110.

[0262] In this example, each eighth power conversion subunit can convert the second DC power of the corresponding energy storage unit into the fifth DC power, and finally multiple eighth power conversion subunits output the fourth DC power.

[0263] The eighth power conversion subunit can be a unipolar unidirectional DC-DC subunit or a unipolar bidirectional DC-DC subunit. When the eighth power conversion subunit is a unipolar bidirectional DC-DC 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 feed it to the AC power grid in the aforementioned example through the input module 130, thus realizing the free conversion of power between the grid, charging and storage.

[0264] In the above embodiments, the negative input end of the charging gun is shared or not shared, which can be applied to different power supply scenarios, and the selection range of the circuit structure selection is improved.

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

[0266] Specifically, the second external power supply 220 is used to generate the first alternating current and provide it to the ninth power conversion subunit 132 in the input module 130, which charges each battery subunit in the energy storage module 110. For example, the second external power supply 220 can include a second transformer, the primary winding of which is connected to the alternating current grid, and the secondary winding of which is connected to the ninth power conversion subunit 132. The second transformer converts the second alternating current provided by the alternating current grid into the first alternating current, which is provided to the ninth power conversion subunit 132. The ninth power conversion subunit 132 converts the first alternating current into the third direct current to charge the energy storage module 110.

[0267] For example, the second external power supply 220 is a three-phase alternating current power supply, and the ninth power conversion subunit 132 is a one-way three-phase ACDC subunit or a bidirectional three-phase ACDC subunit. At this time, each phase of the three-phase ACDC subunit is connected to an energy storage unit to charge the corresponding energy storage unit. When the ninth power conversion subunit 132 is a bidirectional three-phase ACDC subunit, not only can it charge the energy storage module 110, but also can feed the electrical energy of the energy storage module 110 to the alternating current grid. In this way, in the three-phase alternating current, a single-phase is realized by an energy storage unit, and three energy storage units can realize the function of three-phase alternating current, for example, three-phase power frequency alternating current with a phase difference of 120°. The specific circuit structure of the one-way 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 subunit 132.

[0269] In the above embodiments, in the case of alternating current provided by the external power supply, the battery subunit can be charged by the ninth power conversion subunit.

[0270] In some embodiments, referring to Figure 12bThe input module 130 includes a plurality of tenth power conversion sub-units, each of which is connected with one energy storage unit, and the plurality of tenth power conversion sub-units are configured to provide charging energy for each energy storage unit based on the first alternating current provided by the second external power supply 220.

[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 F2, a tenth power conversion sub-unit F3, a tenth power conversion sub-unit F4, a tenth power conversion sub-unit F5, a tenth power conversion sub-unit F6, a tenth power conversion sub-unit F7, a tenth power conversion sub-unit F8, a tenth power conversion sub-unit F9, and a tenth power conversion sub-unit F10. n-1 The tenth power conversion sub-unit F1 is connected with the second external power supply 220 and the energy storage unit A1, respectively. n The tenth power conversion sub-unit F2 is connected with the second external power supply 220 and the energy storage unit A2, respectively. n-1 The tenth power conversion sub-unit F3 is connected with the second external power supply 220 and the energy storage unit A3, respectively. n-1 The tenth power conversion sub-unit F4 is connected with the second external power supply 220 and the energy storage unit A4, respectively. n The tenth power conversion sub-unit F5 is connected with the second external power supply 220 and the energy storage unit A5, respectively. n The tenth power conversion sub-unit F6 is connected with the second external power supply 220 and the energy storage unit A6, respectively. 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 supply 220.

[0272] For example, the second external power supply 220 is a three-phase alternating current power supply, and the tenth power conversion sub-units include three, each of which is a unidirectional single-phase ACDC sub-unit or a bidirectional single-phase ACDC sub-unit, at this time, each tenth power conversion sub-unit is connected to one phase of the three-phase alternating current power supply to charge the corresponding energy storage unit. When the tenth power conversion sub-unit is a bidirectional single-phase ACDC sub-unit, not only can the charging of the energy storage module 110 be realized, but also the electrical energy of the energy storage module 110 can be fed to the alternating current grid, and when feeding, the three bidirectional single-phase ACDC sub-units cooperate with each other to form a three-phase alternating current fed to a three-phase alternating current grid, so that in the three-phase alternating current, the single-phase is realized by the energy storage unit, and the three energy storage units can realize the function of the three-phase alternating current. The specific circuit structure of the unidirectional single-phase ACDC sub-unit or the bidirectional single-phase ACDC sub-unit is not limited here.

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

[0274] In the above embodiment, in the case of an alternating current provided by an external power supply, the battery sub-units can be charged by the plurality of tenth power conversion sub-units.

[0275] In some embodiments, with reference to Figure 13The charging device 100 further comprises a wireless communication module 140, 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, so as to interact with external devices through the wireless communication module 140.

[0276] It should be noted that in the above embodiments, various charging device architectures are provided, for example, multiple energy storage units can be connected in series, in parallel or in series-parallel; part or all of the multiple energy storage units can be provided with the first power conversion subunit, the first switch subunit or the first power conversion subunit and the first switch subunit; the charging module can adopt a unipolar power conversion subunit or a bipolar power conversion subunit, and the negative input end of the corresponding charging pile can be shared or not shared; a single phase of three-phase alternating current is realized by an energy storage unit, and three energy storage units can realize the function of three-phase alternating current; the input module can be an alternating current input or a direct current input; and the like.

[0277] In order for those skilled in the art to more clearly understand the present application, specific examples will be described below, but this should not be considered as a limitation of the present application.

[0278] Example one, refer to Figure 14 The energy storage module 110 comprises multiple energy storage units, each energy storage unit comprises a battery subunit and a first power conversion subunit, the first power conversion subunit can be a bidirectional DCDC subunit, the multiple energy storage units are connected in series between the second positive power supply end and the second negative power supply end of the energy storage module 110, and the second positive power supply end and the second negative power supply end of the energy storage module 110 are connected to the DC bus, that is, the multiple energy storage units are connected in series on the DC bus. The charging module 120 comprises a third power conversion subunit 121 and a charging gun 122, the third power conversion subunit 121 has a high-voltage positive input end and a high-voltage negative input end, and a high-voltage positive output end and a high-voltage negative output end, and the third power conversion subunit 121 can be a bipolar bidirectional DCDC subunit. The input module 130 comprises a second power conversion subunit 131, which can be a bidirectional ACDC subunit. The second external power supply 220 comprises a first transformer connected to an alternating current grid.

[0279] When charging the energy storage module 110, the first transformer converts the second alternating current provided by the alternating current grid into the first alternating current, which is converted into direct current through the bidirectional ACDC subunit, and then charges 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 second direct current based on the electrical energy of the battery subunit, the energy storage module 110 obtains first direct current based on the second direct current, the first direct current is converted into fourth direct current through the high-power bipolar bidirectional DCDC subunit, and the fourth direct current charges the device to be charged through the charging gun 122, so as to realize high-power charging and fast charging / super charging of the device to be charged.

[0281] It can be understood that under the action of the bidirectional ACDC subunit and the bipolar bidirectional DCDC subunit, the electrical energy of the device to be charged can also be fed to the energy storage module 110 or the alternating current power grid, so as to realize free switching of electrical energy among the device to be charged, the energy storage module 110 and the alternating current power grid.

[0282] Example two, referring to Figure 15 , the difference between this example and the example shown in Figure 14 is that the fourth power conversion subunit 123 only has a high-voltage positive input end and a high-voltage positive output end, the high-voltage negative input end of the charging gun 122 is directly connected to the second negative power supply end of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared, and the fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit. For the same content, to avoid redundancy, this will not be repeated here.

[0283] Example three, referring to Figure 16 , the difference between this example and the example shown in Figure 14 is that a plurality of energy storage units are connected in parallel between the second positive power supply end and the second negative power supply end of the energy storage module 110, that is, the plurality of energy storage units are connected in parallel to the direct current bus.

[0284] Example four, referring to Figure 17 , the difference between this example and the example shown in Figure 16 is that the fourth power conversion subunit 123 only has a high-voltage positive input end and a high-voltage positive output end, the high-voltage negative input end of the charging gun 122 is directly connected to the second negative power supply end of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared, and the fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit.

[0285] Example five, referring to Figure 18 , the difference between this example and the example shown in Figure 14 is that part of the plurality of energy storage units includes a battery subunit, and the other part of the plurality of energy storage units includes a battery subunit and a first power conversion subunit, for example, the energy storage unit A1 includes a battery subunit, the energy storage unit A n includes a battery subunit and a bidirectional DCDC subunit A n .

[0286] Example six, referring toFigure 19 The example shown in FIG. 7 is different from the example shown in FIG. 6 in that the fourth power conversion subunit 123 has only a high-voltage positive input end and a high-voltage positive output end, and the high-voltage negative input end of the charging gun 122 is directly connected to the second negative power supply end of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit. Figure 18 The example shown in FIG. 7 is different from the example shown in FIG. 6 in that the fourth power conversion subunit 123 has only a high-voltage positive input end and a high-voltage positive output end, and the high-voltage negative input end of the charging gun 122 is directly connected to the second negative power supply end of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DCDC subunit.

[0287] Example Seven, referring to FIG. 8, Figure 20 The example shown in FIG. 8 is different from the example shown in FIG. 7 in that each energy storage unit includes a battery subunit and a first switch subunit, and the first switch subunit can be a protection switch to protect the energy storage unit in abnormal situations. Figure 16 The example shown in FIG. 8 is different from the example shown in FIG. 7 in that each energy storage unit includes a battery subunit and a first switch subunit, and the first switch subunit can be a protection switch to protect the energy storage unit in abnormal situations.

[0288] In the above examples one to seven, the energy storage module 110 and the charging module 120 are connected to the DC bus, that is, the charging device 100 adopts a DC bus design. When the energy storage module 110 and the charging module 120 are both provided in multiple, multiple charging devices 100 share the DC bus. When the charging device 100 adopts a DC bus design, in the case where 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 kilowatt-hours, 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 not greater than 1:4.

[0289] Example Eight, referring to FIG. 9, Figure 21 The energy storage module 110 includes three energy storage units A1, A2 and A3 and a selection unit 111, each energy storage unit includes a battery subunit, and the selection unit 111 includes three second switch subunits K1, K2 and K3. The charging module 120 includes a fifth power conversion subunit 124 and a charging gun 122, the fifth power conversion subunit 124 has a high-voltage positive input end and a high-voltage negative input end, and a high-voltage positive output end and a high-voltage negative output end, and the fifth power conversion subunit 124 can be a bipolar bidirectional DCDC subunit. The input module 130 includes three tenth power conversion subunits, which can be bidirectional single-phase ACDC subunits. The second external power supply 220 includes a second transformer connected to an alternating current power grid.

[0290] When charging the energy storage module 110, the second transformer converts the second alternating current provided by the alternating current grid into the first alternating current, which is converted into direct current by the bidirectional single-phase AC-DC subunit, and then charges the corresponding battery subunit. Among them, each bidirectional single-phase AC-DC subunit is connected to one phase of the alternating current bus, for example, the first bidirectional single-phase AC-DC subunit is connected to phase A, the second bidirectional single-phase AC-DC subunit is connected to phase B, and the third bidirectional single-phase AC-DC subunit is connected to phase C. It should be noted that under the action of the bidirectional single-phase AC-DC subunit, when the electrical energy in the energy storage module 110 is fed to the alternating current grid, the three bidirectional single-phase AC-DC subunits can cooperate with each other to generate three-phase alternating current with a phase difference of 120°, so that the output of three-phase alternating current can be realized through the three energy storage units.

[0291] When charging the device to be charged, the energy storage unit provides the second direct current based on the electrical energy of the battery subunit, and the energy storage module 110 selectively outputs the second direct current to obtain the first direct current through the selection unit 111, the first direct current is converted by the high-power bipolar bidirectional DC-DC subunit to obtain the fourth direct current, and the fourth direct current is used to charge the device to be charged through the charging gun 122, so as to realize high-power charging and fast / ultra-fast charging of the device to be charged. In some examples, the second switch subunits K1, K2 and K3 can be closed one by one in time sequence to make the electrical energy in the three energy storage units consistent.

[0292] It can be understood that under the action of the bidirectional single-phase AC-DC subunit and the bipolar bidirectional DC-DC subunit, the electrical energy of the device to be charged can also be fed to the energy storage module 110 or the alternating current grid, so as to realize the free switching of electrical energy between the device to be charged, the energy storage module 110 and the alternating current grid.

[0293] Example nine, with reference to Figure 22 Compared with the examples shown in Figure 21 The difference is that the sixth power conversion subunit 125 only has a high-voltage positive input end and a high-voltage positive output end, the high-voltage negative input end of the charging gun 122 is directly connected to the second negative power supply end of the energy storage module 110, that is, the negative poles of the charging gun 122 and the energy storage module 110 are shared, and the sixth power conversion subunit 125 can be a unipolar bidirectional DC-DC subunit.

[0294] In the above-mentioned examples eight to nine, the energy storage module 110 and the charging module 120 are connected to the alternating current bus, that is, the charging device 100 adopts the alternating current bus design. When the energy storage module 110 and the charging module 120 are provided as a plurality of modules, the plurality of charging devices 100 share the alternating current bus.

[0295] In the above examples one to nine, the charging device 100 can communicate with external devices, including but not limited to cloud services / monitoring platforms, through the wireless communication module 140, and achieve 4G / 5G communication, etc. The cloud services / monitoring platforms can select appropriate peak and valley periods according to the peak and valley periods of the region where the charging device 100 is located, and issue them to the charging device 100, so that the charging device 100 can achieve peak clipping and valley filling. For example, during the peak period of the alternating current power grid, the alternating current power grid does not charge the energy storage module 110, and during the valley period of the alternating current power grid, the energy storage module 110 is charged by the alternating current power grid.

[0296] It should be noted that the above examples one to nine are only exemplary, and based on the inventive concept of the present application, through reasonable setting of the foregoing architecture, they should all be within the protection scope of the present application.

[0297] In order to further illustrate the implementation manner of the scheme that the rated charging output power of the charging module of the present application is greater than or equal to 290 kilowatts, the following will be described in detail with respect to the battery sub-units.

[0298] In the present application, each energy storage unit can include a battery sub-unit, the battery sub-unit can include one or more single cells, the single cell can include an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator film. The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer arranged 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 sheet includes a negative electrode current collector and a negative electrode film layer arranged 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 can be a single layer film layer or at least two layer film layers. Optionally, the negative electrode film layer includes at least two layer film layers. Similarly, the positive electrode film layer can be a single layer film layer or at least two layer film layers. During the charging and discharging process of the single cell, active ions such as lithium ions are inserted and extracted between the positive electrode sheet and the negative electrode sheet, and the electrolyte plays a role in conducting active ions between the positive electrode sheet and the negative electrode sheet.

[0299] The following will be specifically described with respect to the electrolyte, the positive electrode sheet, the negative electrode sheet and the separator film:

[0300] [Electrolyte]

[0301] In some embodiments, the electrolyte includes an electrolyte salt, and 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.

[0302] By setting the electrolyte to include lithium hexafluorophosphate at the above concentration, the battery subunit has a high ionic conductivity, thereby improving the charging rate of the charging device, and also has a high interface stability and a high thermal stability; lithium hexafluorophosphate has a small influence on the severity of thermal runaway, so that the battery subunit has a suitable severity of thermal runaway and a low risk of thermal diffusion, thereby making the charging device have a high reliability when the power output is above 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 methyl ethyl carbonate. Further optionally, the carbonate solvent includes one or more of ethylene carbonate, dimethyl carbonate, and methyl ethyl carbonate.

[0305] Further optionally, the mass content of the carbonate solvent in the organic solvent is 10% to 70%, optionally one of 30% to 50% or 10% to 30% or 30% to 70%.

[0306] Illustratively, the mass content of the carbonate solvent in the organic solvent is 10%, 20%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 40%, 45%, 48%, 50%, 55%, 60%, 65%, 70%, or a range composed of any two of the above values. The carbonate solvent at the above mass content can further improve the conductivity of the electrolyte at room temperature, which is conducive to the migration of lithium ions.

[0307] Illustratively, the carbonate solvent includes one or more of ethylene carbonate, dimethyl carbonate, and methyl ethyl carbonate, and the mass content of the carbonate solvent is 30% to 50%.

[0308] Adding the carbonate solvent to the electrolyte can improve various performances of the battery subunit, for example, can improve the charge-discharge efficiency, cycle performance, low-temperature performance, and high-voltage stability of the battery subunit, so that the battery subunit can improve the battery discharge stability at high power output.

[0309] In some embodiments, the electrolyte includes an electrolyte salt, and the electrolyte salt includes lithium hexafluorophosphate, and the concentration of lithium hexafluorophosphate is in the range of 0.5 mol / L to 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 composed of any two of the above values.

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

[0312] By setting the electrolyte to include lithium hexafluorophosphate in the above 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 less influence on the severity of thermal runaway, so that the battery subunit has a suitable thermal runaway severity, and the risk of thermal diffusion is lower, so that the charging device has higher reliability when the power output is above 350kW.

[0313] In some embodiments, the electrolyte salt further includes a fluorine-containing sulfonimide salt, and the concentration of the fluorine-containing sulfonimide salt is in the range of 0.2mol / L-0.5mol / L.

[0314] The fluorine-containing sulfonimide salt can include one or more of lithium bisfluorosulfonimide LiFSI and lithium bis(trifluoromethylsulfonyl)imide LiTFSI.

[0315] Optionally, the lithium salt includes lithium bisfluorosulfonimide LiFSI and lithium hexafluorophosphate LiPF6, the molar concentration of lithium bisfluorosulfonimide LiFSI is 0.2mol / L to 0.5mol / L, and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.5mol / L to 1.0mol / L.

[0316] For example, the molar concentration of lithium bisfluorosulfonimide LiFSI is 0.4mol / L to 0.5mol / L, and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.7mol / L. 66

[0317] For example, the molar concentration of lithium bisfluorosulfonimide LiFSI is 0.5mol / L, and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.5mol / L.

[0318] For example, the molar concentration of lithium bisfluorosulfonimide LiFSI is 0.2mol / L, and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.8mol / L.

[0319] Optionally, the ratio of the molar concentration of lithium bisfluorosulfonimide and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.2 to 1.0, which can be 0.2 to 0.5. For example, the ratio of the molar concentration of lithium bisfluorosulfonimide and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, or a range composed of any two of the above values.

[0320] ​In the embodiments of the present application, the types and contents of the inorganic components / lithium salt in the electrolyte are in the meanings known in the art, and can be detected by using the devices and methods known in the art, for example, the qualitative or quantitative analysis of the inorganic components / lithium salt in the electrolyte can be performed by ion chromatography according to the standard JY / T020-1996 "General Ion Chromatography Analysis Method". In the embodiments of the present application, the newly prepared electrolyte can be taken as the sample, the free electrolyte of the fresh battery can be taken as the sample, or the free electrolyte obtained from the battery which has been discharged to the lower limit cut-off voltage so that the charged state of the battery is about 0% SOC by reverse disassembly can be taken as the sample, and the ion chromatography analysis method is used for detection.

[0321] In the embodiments of the present application, the types and contents of the organic components in the electrolyte are in the meanings known in the art, and can be detected by using the devices and methods known in the art, for example, the qualitative and quantitative analysis of the organic components in the electrolyte can be performed by gas chromatography according to the standard GB / T9722-2006 "Chemical Reagents-General Gas Chromatography Method". In the embodiments of the present application, the newly prepared electrolyte can be taken as the sample, the free electrolyte of the fresh battery can be taken as the sample, or the free electrolyte obtained from the battery which has been discharged to the lower limit cut-off voltage so that the charged state of the battery is about 0% SOC by reverse disassembly can be taken as the sample, and the ion chromatography analysis method is used for detection.

[0322] In the embodiments of the present application, after the quantitative and qualitative detection of each component in the electrolyte, each component is classified, the chain carboxylate solvents, carbonate solvents (for example, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate) are taken as the constituent components of the organic solvent, and the mass content of each component is calculated based on 100% of the mass of the organic solvent.

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

[0324] Since the fluorine-containing sulfonimide salt has the characteristics of low viscosity and high ionic conductivity, the electrolyte including the fluorine-containing sulfonimide salt with the above concentration is beneficial to improve the charging rate of the battery subunit, and further improve 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] The chain carboxylate solvent includes a compound with the following structure:

[0327]

[0328] wherein R1 comprises at least one of a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 haloalkyl group, and R2 comprises a C1-C5 alkyl group and / or a C1-C5 haloalkyl group.

[0329] The mass content of the chain carboxylate solvent relative to the mass of the organic solvent is greater than or equal to 5% and less than or equal to 75%, which can be greater than or equal to 10% and less than or equal to 75%, which can be 30% to 70%, which can be 50% to 70%. Exemplarily, the mass content of the chain carboxylate solvent is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or a range formed by any two of the above values.

[0330] When the mass content of the chain carboxylate solvent is within the above range, the viscosity of the electrolyte system is relatively small, which is conducive to the migration of lithium ions.

[0331] The chain carboxylate solvent described above has a relatively high conductivity, which is conducive to improving the rapid charging capability of the single battery.

[0332] Optionally, R1 comprises a hydrogen atom, a halogen atom, a C1 to C3 alkyl group, or a C1 to C3 haloalkyl group. Further optionally, R1 comprises a hydrogen atom, a halogen atom, a C1 to C2 alkyl group, or a C1 to C2 haloalkyl group.

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

[0334] In each of the above embodiments, the halogen atom comprises one or more of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, which can optionally comprise a fluorine atom.

[0335] In each of the above embodiments, the haloalkyl group comprises one or more of a fluoroalkyl group, a chloroalkyl group, a bromoalkyl group, and an iodoalkyl group, which can optionally comprise a fluoroalkyl group.

[0336] Exemplarily, the chain carboxylate solvent comprises one or more of a compound represented by formula I-1 to a compound represented by formula I-8,

[0337]

[0338] The technical solution, the solvent comprises a carboxylate solvent, so that the electrolyte can have a higher ionic conductivity and a relatively low viscosity, which is conducive to further improving the rapid charging performance of the charging device, such as the fast charging performance and / or the super charging performance.

[0339] In some embodiments, the electrolyte has an electrical conductivity of 13 mS / cm to 20 mS / cm, optionally 15 mS / cm to 20 mS / cm at room temperature. For example, the electrolyte has an electrical 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 defined by any two of the above values at room temperature.

[0340] When the electrolyte has an electrical conductivity in the above range at room temperature, for example 25°C, the migration rate of lithium ions in the electrolyte is high, which can further reduce the internal resistance of the single battery cell, thereby reducing heat generation and improving the rapid charging performance of the single battery cell.

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

[0342] In some embodiments, the electrolyte has a viscosity of 2.3 mPa s to 3.5 mPa s at room temperature. For example, the electrolyte has a viscosity of 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 defined by any two of the above values.

[0343] When the electrolyte has a viscosity in the above range at room temperature, for example 25°C, the migration rate of lithium ions in the electrolyte is high, which can further reduce the internal resistance of the single battery cell, thereby reducing heat generation and improving the rapid charging performance of the single battery cell.

[0344] In embodiments of the present application, the viscosity of the electrolyte is the meaning known in the art, which can be detected by using devices and methods known in the art, for example, by referring to GB / T 10247-2008.

[0345] In some embodiments, the electrolyte has a density of 1.05 g / mL to 1.35 g / mL at room temperature, for example 25°C. For example, the electrolyte has a density of 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 defined by any two of the above values.

[0346] When the electrolyte has a density in the above range, the migration rate of lithium ions in the electrolyte is high, which can further reduce the internal resistance of the single battery cell, thereby reducing the heat generation and improving the rapid charging performance of the single battery cell.

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

[0348] The electrolyte comprises 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 the actual needs.

[0349] In some embodiments, the electrolyte further comprises an additive. The additive can comprise a negative electrode film-forming additive, a positive electrode film-forming additive, or an additive capable of improving certain performance of the battery, for example, an additive capable of improving the overcharge performance of the battery, an additive capable of improving the high-temperature performance of the battery, an additive capable of improving the low-temperature power performance of the battery, etc.

[0350] In some embodiments, the additive comprises one or more of a carbonate additive, a sulfur-containing additive, and a lithium salt additive, and can optionally comprise at least two of them. The above additives can improve the performance of the interface film on the positive electrode side and / or the negative electrode side, which is beneficial to improving the rapid charging performance of the single battery cell and improving the cycle performance.

[0351] In some embodiments, the mass content of the additive in the electrolyte is 1% to 10%, which can be 2% to 8%, and further can be 3.5% to 8%. For example, the mass content of the additive in the electrolyte is 1%, 2%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range defined by any two of the above values.

[0352] The additive in the above mass content can effectively improve the performance of the interface film on the positive electrode side and / or the negative electrode side, which is beneficial to improving the rapid charging performance of the single battery cell and improving the cycle performance.

[0353] For example, the carbonate additive comprises one or more of vinylene carbonate VC and fluoroethylene carbonate FEC.

[0354] Exemplarily, the sulfur-containing additive comprises one or more of vinyl sulfonate DTD, bis vinyl sulfonate 2-DTD, butylene sulfite BS, 1,3-propane sultone PS, ethylene sulfite ES, and methyl methylene disulfonate MMDS.

[0355] Optionally, the lithium salt additive comprises one or more of lithium difluorophosphate LiPO2F2, lithium difluoro oxalate borate LiDFOB, lithium tetrafluoroborate LiBF4, and lithium bisoxalate borate LiBOB.

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

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

[0358] Optionally, the mass content of the vinylene carbonate VC in the electrolyte is 0.5% to 9%, and the mass content of the fluoroethylene carbonate FEC in the electrolyte is 0.1% to 4%.

[0359] Further optionally, the mass content of the vinylene carbonate VC in the electrolyte is 2% to 6%, and the mass content of the fluoroethylene carbonate FEC in the electrolyte is 0.5% to 3%.

[0360] In some embodiments, the monomer battery cell satisfies 2.45 g / Ah ≤ d / A ≤ 3.5 g / Ah, and optionally 2.45 g / Ah ≤ d / A ≤ 3.3 g / Ah, where d represents the mass of the electrolyte in the monomer battery cell, in units of g, and A represents the rated capacity of the monomer battery cell, in units of Ah. Exemplarily, d / A can be 3.5 g / Ah, 3.3 g / Ah, 3.2 g / Ah, 3.0 g / Ah, 2.8 g / Ah, 2.5 g / Ah, 2.45 g / Ah, or a range formed by any two of the above values.

[0361] d / A can reflect the liquid retention capacity of the electrolyte. When d / A is in the above range, the electrolyte can better infiltrate the positive and negative electrode sheets, and can improve the migration rate of lithium ions in the liquid phase, which is conducive to improving the rapid charging capacity of the monomer battery cell.

[0362] In the embodiments of the present application, d / A of the monomer battery cell can be understood as a liquid retention coefficient, which can be detected by using devices and methods known in the art. For example, GB / T31486-2015 “Electric Performance Requirements and Test Methods for Power Batteries for Electric Vehicles” can be used as an example to illustrate the case where the upper limit voltage of the battery is 3.65V and the discharge cutoff voltage of the battery is 2.0V.

[0363] The monomer cell is charged to 3.65V at 0.33C at 25°C, then charged to 0.05C at constant voltage, and then discharged to 2.0V at 0.33C at constant current, to obtain the capacity A discharged as the denominator, the monomer cell is weighed as M0, then the positive electrode plate, the negative electrode plate, the separator and the electrolyte are disassembled, and the free electrolyte is in a bag, all the solid components are placed in a 60°C oven for more than 4 hours (including but not limited to the positive electrode plate, the negative electrode plate, the separator, and other mechanical parts of the disassembled monomer cell), then all the components of the monomer cell are weighed again M1, and the weight difference between M0 and M1 is taken as the numerator. The liquid retention coefficient is equal to the value obtained by dividing the weight difference d between M0 and M1 by the capacity A.

[0364] [the negative electrode plate]

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

[0366] Optionally, the resistance of the negative electrode plate is 0.001Ω to 0.005Ω. Illustratively, 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 formed by any two of the above values.

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

[0368] In this way, when the resistance of the negative electrode plate is in the above range, it is beneficial to reduce the internal resistance of the monomer cell, can improve the conductivity of the battery subunit, and further improve the charging rate of the battery subunit, which is beneficial to improve the rapid charging performance of the battery device.

[0369] In the embodiments of the present application, the resistance of the negative electrode plate has the meaning known in the art and can be detected by using devices and methods known in the art, and the detection method is as described above for the resistance test method of the positive electrode plate.

[0370] In some embodiments, the negative 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 can further include natural graphite. Specifically, the carbon-based material can include graphite particles, or the carbon-based material can 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 percentage of the natural graphite can be greater than that of the artificial graphite.

[0372] The carbon-based material of at least one of natural graphite and artificial graphite is used as the negative active material layer, both of which have good electrical conductivity and high theoretical specific capacity. Natural graphite has high crystallinity and regular layered structure, which is beneficial to the rapid embedding and extraction of lithium ions, thereby improving the charging and discharging efficiency of the battery; artificial graphite can precisely adjust its microstructure and performance by controlling the production process, enhance the cycle stability of the single cell, and prolong the service life of the single cell, thereby prolonging the cycle life and charging stability of the charging device 100 in the scene of high-power charging.

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

[0374] In the case of using a single-layer film layer for the negative electrode film layer, the negative 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 using a single-layer film layer, the volume average particle size Dv50 of the negative 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 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 formed by any two of the above values. In other embodiments, the volume average particle size Dv50 of the negative electrode film layer can be between 8.2 μm and 18.5 μm, for example, can be 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm, 14 μm, 15 μm, 16.2 μm, 18 μm, 18.5 μm, or a range formed by any two of the above values.

[0375] In the case of using at least two film layers for the negative electrode film layer, the negative active material in the negative electrode film layer includes a carbon-based material, and optionally also includes a silicon-based material, which can 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 can 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 in the range of 8.2 μm-13.5 μm, which can balance the specific surface area and the compaction density. A smaller particle size can provide a larger specific surface area, increase the reaction sites of lithium ions, and improve the charge-discharge rate performance of the single battery cell; and a proper particle size can have a higher compaction density, reduce the voids between active materials, and improve the energy density of the single battery cell, so as to achieve a good balance between the rate performance and the energy density of the single battery cell to meet the charging requirements of the charging device 100 at different charging 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 arranged in a stack, the first negative electrode active material layer is located on the side close to the negative electrode current collector, the volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer is 9.5 μm-18.5 μm, and the volume average particle size Dv50 of the negative electrode active material in the second negative electrode active material layer is 7.8 μm-14.3 μm.

[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 in the above range, on the one hand, the solid-phase transmission path of lithium ions can be shortened to improve the rapid charging performance, and on the other hand, the material is not easy to agglomerate during the preparation process, which can improve the stability of the material. 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 in the above volume average particle size range cooperate to facilitate the construction of the gradient pore difference of the second negative electrode active material layer and the first negative electrode active material layer, reduce the tortuosity of lithium ion transmission, and improve the rapid 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 of the first negative electrode film layer and the second negative electrode film layer can be regular or irregular, and is optionally irregular.

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

[0382] The negative electrode film layer includes at least two film layers, and the layered coating is beneficial to improve the rapid charging performance of the single battery cell. In particular, when the first negative electrode film layer and the second negative electrode film layer are different, the pore difference of the negative electrode film layer can be constructed, the tortuosity of lithium ion transmission is reduced, and the rapid charging performance of the single battery cell is improved.

[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 to improve 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] The particle size difference in the first negative electrode film layer and the second negative electrode film layer can improve the rapid charging performance of the single battery cell. Specifically, during the rapid charging process, the overpotential of the second negative electrode film layer is usually high, and the bottleneck of rapid charging is mainly in the second negative electrode film layer. In the embodiments of the present application, the particle size in the second negative electrode film layer is relatively small, which can shorten the solid-phase transmission path of lithium ions, improve the rapid charging performance, and improve the problem of lithium extraction on the surface of the negative electrode sheet.

[0385] Optionally, the negative electrode active material in the first negative electrode film layer is in a particle form, and the volume average particle size Dv50 thereof is 9.5 μm to 18.5 μm, which can be 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 formed by 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, which can be 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 in the above range, on the one hand, the solid-phase transmission path of lithium ions can be shortened, and the rapid charging performance can be improved. On the other hand, the material is not easy to agglomerate during the preparation process, and the stability of the material can be improved.

[0387] Optionally, the volume average particle size Dv50 of the negative active material in the second negative electrode film layer is 7.8 μm to 14.3 μm, or 7.8 μm to 11.3 μm. For example, the volume average particle size Dv50 of the negative active material in the second negative electrode film layer is 7.8 μm, 8.0 μm, 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.3 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm, 13.8 μm, 14 μm, 14.1 μm, 14.3 μm, or a range defined by any two of the above values. When the second negative electrode film layer comprises 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, or 7.8 μm to 11.3 μm.

[0388] When the volume average particle size Dv50 of the negative active material in the second 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 rapid charging performance can be improved. On the other hand, the material is less likely to agglomerate during preparation, and the stability of the material can be improved. On the other hand, the negative active material in the second negative electrode film layer and the negative active material in the first negative electrode film layer cooperate to facilitate the construction of a gradient pore difference between the second negative electrode film layer and the first negative electrode film layer, reduce the tortuosity of lithium ion transmission, and improve the rapid charging performance of the single battery cell.

[0389] In the embodiments of the present application, the volume average particle size Dv50 of the negative active material has the meaning known in the art, and can be detected by using the devices and methods known in the art. The detection method is as described above in the volume average particle size Dv50 test method of the positive active material.

[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 more densely packed, so that the energy density of the single battery cell is improved, and the first negative electrode film layer is relatively less densely packed, and the pores are more abundant, which can improve the rapid charging performance of the single battery cell. When the negative active material comprises 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 3Up to 1.21 g / cm 3 For example, 0.82 g / cm³ 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 1.10 g / cm 3 1.12 g / cm 3 1.15g / cm 3 1.18 g / cm 3 1.20g / cm 3 1.21 g / cm 3 Or it can be a range consisting of any two of the above values. When the tap density of the carbon-based material in the first negative electrode film is within a suitable range, it can improve the fast charging performance of a single battery cell.

[0392] Optionally, the tap density of the carbon-based material in the second negative electrode film is 0.90 g / cm³. 3 Up to 1.25 g / cm 3 For example, 0.90 g / cm³ 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 1.10 g / cm 3 1.12 g / cm 3 1.15g / cm 3 1.18 g / cm 3 1.20g / cm 3 1.21 g / cm 3 1.22g / cm 3 1.23g / cm 3 1.24 g / cm 3 ³ 1.25g / cm 3 Or it could be a range consisting of any two of the above values. When the tap density of the carbon-based material in the second negative electrode film is within a suitable range, it can improve the energy density of the single cell.

[0393] In the embodiments of the present application, the tap density of the material is a meaning known in the art, which can be measured by instruments and methods known in the art. For example, GB / T 5162-2006 can be referred to, and a powder tap density tester can be used for measurement. The testing instrument can be Dandong Bitai BT-301.

[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, or 4:6 to 6:4. For example, 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 formed by any two of the above values. By adjusting the thickness ratio of the first negative electrode film layer and the second negative electrode film layer, the gradient pore difference between the upper and lower layers can be further increased, the tortuosity of lithium ion transmission can be reduced, and the rapid charging capacity of the single battery cell can be improved.

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

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

[0397] In the embodiments of the present application, the tap density of the negative electrode film layer of the single battery cell at 100% state of charge is a meaning known in the art, which can be detected by devices and methods known in the art, and the detection method is the same as the tap density test method of the positive electrode film layer described above.

[0398] When the tap density of the negative electrode film layer is in the above range, the energy density of the battery cell can be improved, and since the negative electrode active material in the negative electrode film layer is packed more closely, the contact resistance between particles is smaller, which can further reduce the resistance of the electrode sheet, thereby reducing the heat generation.

[0399] In some embodiments, the powder compaction density of the negative active material under a pressure of 20000 N is 1.5 g / cm 3 to 1.85 g / cm 3 , optionally 1.55 g / cm 3 to 1.65 g / cm 3 . For example, the powder compaction density of the negative active material under a pressure of 20000 N is 1.5 g / cm 3 , 1.55 g / cm 3 , 1.6 g / cm 3 , 1.65 g / cm 3 , 1.7 g / cm 3 , 1.75 g / cm 3 , 1.8 g / cm 3³ , 1.85 g / cm 3 , or a range defined by any two of the above values.

[0400] When the powder compaction density of the negative active material under a pressure of 20000 N is within the above range, the energy density of the single battery cell can be improved, and the negative active material in the negative film layer can be more closely packed, the contact resistance between particles is smaller, which can further reduce the resistance of the electrode sheet, thereby reducing the heat generation.

[0401] In the embodiments of the present application, the powder compaction density of the material is the meaning known in the art, which can be detected by the methods and devices known in the art according to the test standard GB / T24533-2009. For example, a certain amount of negative active material is taken as a sample, added to a mold with a bottom area of 1.327 cm 2² of the UTM7305 electronic pressure testing machine, pressurized to 2000 kg (equivalent to 20000 N), keep pressure for 30 s, then release pressure, keep for 10 s, then record and calculate the powder compaction density of the negative active material under the action of 20000 N force.

[0402] In some embodiments, the charge gram capacity of the negative active material at a 0.1C rate is 350 mAh / g to 480 mAh / g. For example, the charge gram capacity of the negative active material at a 0.1C rate is 350 mAh / g, 355 mAh / g, 360 mAh / g, 365 mAh / g, 370 mAh / g, 375 mAh / g, 380 mAh / g, 385 mAh / g, 390 mAh / g, 395 mAh / g, 400 mAh / g, 410 mAh / g, 420 mAh / g, 430 mAh / g, 440 mAh / g, 450 mAh / g, 460 mAh / g, 470 mAh / g, 480 mAh / g, or a range defined by any two of the above values.

[0403] When the charged gram capacity of the negative active material at 0.1C rate is in the above range, the energy density of the single battery cell is relatively high.

[0404] In the embodiments of the present application, the charged gram capacity of the negative active material at 0.1C rate is in the meaning known in the art, which can be detected by using the devices and methods known in the art, and the detection method is as follows: the charged gram capacity of the positive active material at 0.1C rate is tested.

[0405] In some embodiments, the negative active material layer comprises a carbon-based material, which has high cycle stability and can improve the cycle performance of the single battery cell. Optionally, the mass fraction of the carbon-based material in the negative active material can be greater than or equal to 80% and less than or equal to 100%.

[0406] The positive active material of the present application is mainly a lithium-containing phosphate system with an olivine structure, and the negative active material is mainly a carbon-based material system. When the two are used together, the cycle performance of the single battery cell is excellent.

[0407] Optionally, the carbon-based material comprises graphite particles, and the graphitization degree of the graphite particles is 92.0% to 94.5%. For example, the graphitization degree of the graphite particles is 92.0%, 92.5%, 93%, 93.5%, 94%, 94.5% or a range formed by any two of the above values.

[0408] When the graphitization degree of the graphite particles is in the above range, the conductive performance of the graphite particles is excellent, which can reduce the heat generation of the negative electrode sheet, reduce the heat generation of the single battery cell, and improve the rapid charging performance of the single battery cell.

[0409] In some embodiments, the graphite particles comprise artificial graphite and a carbon coating layer, the artificial graphite comprises secondary particles, the secondary particles comprise a plurality of primary particles, and the carbon coating layer is coated on the surface of the artificial graphite. The carbon in the carbon coating layer is mainly amorphous carbon, which refers to a transition state carbon material with a very low degree of graphitization and crystallization, and an approximate amorphous state (or a structure with no fixed shape and periodicity). In the present application, amorphous carbon refers to the product after carbonization treatment of an organic carbon source.

[0410] The artificial graphite comprises secondary particles, the migration path of lithium ions in the artificial graphite is more, and the migration path in the primary particles is shorter, which can improve the migration rate of lithium ions, the carbon coating layer has more end faces and defects, so that the number of sites capable of deintercalating lithium ions increases, and the conductivity of the carbon coating layer is excellent, which can reduce the internal resistance of the negative electrode sheet and 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. Illustratively, the mass content of the carbon coating layer is 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a range between any two of the foregoing values.

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

[0413] In the embodiments 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 then forming a carbon coating layer on at least part of the surface of the artificial graphite particles after carbonization treatment.

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

[0415] Optionally, the carbonization treatment temperature is 700°C to 1800°C. Optionally, the carbonization treatment temperature is 1000°C to 1300°C. When the carbonization treatment temperature is within the appropriate range, the organic carbon source can be carbonized, and a coating layer containing amorphous carbon can be formed on at least part of the surface of the artificial graphite.

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

[0417] In some embodiments, the negative electrode active material can further include a silicon-based material. The introduction of the silicon-based material can improve the capacity of the negative electrode active material and increase the energy density of the single battery.

[0418] Optionally, the mass content of silicon in the silicon-based material is 0.3% to 10.0%, and can be 1% to 6%, based on the mass of the negative electrode active material. Illustratively, 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 between any two of the foregoing values.

[0419] When the mass content of silicon in the silicon-based material is within the foregoing range, the capacity of the negative electrode active material can be improved, and the energy density of the single battery can be improved.

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

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

[0422] The qualitative and quantitative detection of each substance or element in the present application can be performed by using suitable devices and methods known to those skilled in the art, and the relevant detection methods can refer to domestic and foreign detection standards, domestic and foreign enterprise standards, etc., and those skilled in the art can also adaptively change certain detection steps / instrument parameters from the perspective of detection accuracy to obtain more accurate detection results. One detection method can be used for qualitative or quantitative determination, or several detection methods can be used jointly for qualitative or quantitative determination.

[0423] For example, the negative electrode sheet or the negative active material can be subjected to X-ray powder diffraction test and qualitative analysis by JIS / K0131-1996 X-ray Diffraction Analysis Method General.

[0424] Artificial graphite and natural graphite can be distinguished by SEM cross-sectional SEM images taken by scanning electron microscope SEM, there are gaps between flaky structures in the SEM cross-sectional image of natural graphite, the SEM cross-sectional image of artificial graphite is dense and has no obvious gap, or distinguished by XRD spectrum obtained by X-ray diffraction method, there are obvious 2H phase and 3R phase in the XRD spectrum of natural graphite, and there is only 2H phase in the XRD spectrum of artificial graphite.

[0425] In some embodiments, the powder resistivity of the negative active material is 0.005 Ω•cm to 0.043 Ω•cm, and optionally 0.04 Ω•cm. Illustratively, the powder resistivity of the negative active material can be 0.043 Ω•cm, 0.04 Ω•cm, 0.035 Ω•cm, 0.03 Ω•cm, 0.025 Ω•cm, 0.02 Ω•cm, 0.015 Ω•cm, 0.01 Ω•cm, 0.005 Ω•cm, or a range formed by any two of the above values.

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

[0427] In the embodiments of the present application, the powder resistivity of the negative active material has the meaning known in the art, and can be detected by using devices and methods known in the art, and the detection method is as described above in the powder resistivity test method of the positive active material.

[0428] In some embodiments, after the single battery cell is subjected to 10 cycles of BOL full charge test, the thickness of the first negative electrode film layer is 15-65 μm, for example, 15 μm, 17 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 57 μm, 58 μm, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm, 65 μm, or a range defined by any two of the above values. When the thickness of the first negative electrode film layer is within the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transmission can be reduced, and the rapid charging capability of the single battery cell can be improved.

[0429] In some embodiments, after the single battery cell is subjected to 10 cycles of BOL full charge test, the thickness of the second negative electrode film layer is 15-65 μm, for example, 15 μm, 17 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 57 μm, 58 μm, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm, 65 μm, or a range defined by any two of the above values. When the thickness of the second negative electrode film layer is within the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transmission can be reduced, and the rapid charging capability of the single battery cell can be improved.

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

[0431] The BOL full charge test procedure is as follows: at 25℃, the battery is charged at a charging rate of 0.33C of the nominal capacity to 3.65 V, then charged at 3.65 V to 0.05C, and then rested for 10 min, then discharged at a discharge rate of 0.33C to 2.0 V, and then rested for 10 min. The above one cycle of charging and discharging is one cycle, and 10 cycles are repeated. Then, the battery is charged at a charging rate of 0.33C of the nominal capacity to 3.65 V, and then charged at 3.65 V to 0.05C, which is the BOL full charge state. In the BOL full charge state, the negative electrode sheet is disassembled, the thickness direction of the cross section of the middle region of the negative electrode sheet is observed using a scanning electron microscope, the interface between the first negative electrode film layer and the second negative electrode film layer is distinguished, the thickness of each layer is measured, for example, the thickness of the first negative electrode film layer at 10 positions is measured, and the average value is calculated as the average thickness of the first negative electrode film layer. The thickness of the second negative electrode film layer at 10 positions is measured, and the average value is calculated as the average thickness of the second negative electrode film layer.

[0432] In some embodiments, after the monomer battery cell is subjected to the End Of Life (EOL) full charge test, the thickness of the first negative electrode film layer is 15 μm to 70 μm, for example, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 35 μm, 40 μm, 43 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 66 μm, 67 μm, 68 μm, 69 μm, 70 μm, or a range formed by any two of the above values. When the thickness of the first negative electrode film layer is in the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transmission can be reduced, and the rapid charging capability of the monomer battery cell can be improved.

[0433] In some embodiments, after the monomer battery cell is subjected to the End Of Life (EOL) full charge test, the thickness of the second negative electrode film layer is 15 μm to 70 μm, for example, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 35 μm, 40 μm, 43 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 66 μm, 67 μm, 68 μm, 69 μm, 70 μm, or a range formed by any two of the above values. When the thickness of the second negative electrode film layer is in the above range, the gradient pore difference between the first negative electrode film layer and the second negative electrode film layer can be increased, the tortuosity of lithium ion transmission can be reduced, and the rapid charging capability of the monomer battery cell can be improved.

[0434] In the embodiments of the present application, for example, the upper limit voltage of battery charging is 3.65 V, and the discharge cut-off voltage of the battery is 2.0 V.

[0435] The EOL full charge test procedure is as follows: at 60°C, charge at a charge rate of 0.33C of the nominal capacity of the battery to 3.65V, then charge at a constant voltage of 3.65V to 0.05C, stand for 10min, then discharge at a discharge rate of 0.33C to 2.0V, stand for 10min, the above one charge and discharge is one cycle, until the battery capacity decays to 80% of the nominal capacity to stop the test. 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 full charge state, in the EOL full charge state, disassemble the negative electrode sheet, use a scanning electron microscope to observe the thickness direction of the cross section of the middle region of the negative electrode sheet, distinguish the two regions according to the interface of the first negative electrode film layer and the second negative electrode film layer, and measure the thickness of the two regions respectively, for example, measure the thickness of 10 positions of the first negative electrode film layer respectively, calculate the average value as the average thickness of the first negative electrode film layer, and measure the thickness of 10 positions of the second negative electrode film layer, calculate the average value as the average thickness of the second negative electrode film layer.

[0436] In some embodiments, in the case of a single-layer film layer (different from the above-mentioned double-layer film layer) for the negative electrode film layer, the negative electrode film layer further comprises a lithium-containing binder. Optionally, the mass content of the lithium-containing binder in the negative electrode film layer is 0.1% to 1%. Illustratively, the mass content of the lithium-containing binder in the negative electrode film layer is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or a range composed of any two of the above-mentioned values. The lithium element in the lithium-containing binder can exist in ionic form, which can increase the number of free-moving lithium ions in the negative electrode film layer, shorten the distance of lithium ion diffusion to the surface of the negative electrode film layer, increase the de-intercalation rate of lithium ions, and improve the rapid charging performance of the single battery. Optionally, the negative electrode film layer can further comprise a negative electrode binder, for example, the negative electrode binder comprises at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based acrylic resin (for example, polyacrylic acid PAA, polymethylacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0437] Optionally, the mass content of lithium element in the lithium-containing binder is 3% to 10%. Illustratively, the mass content of lithium element in the lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range composed of any two of the above-mentioned values. The mass content of lithium element is calculated based on the mass of the lithium-containing binder. When the mass content of lithium element is in the above-mentioned range, the number of free-moving lithium ions in the negative electrode film layer can be relatively large, which can further shorten the distance of lithium ion diffusion to the surface of the negative electrode film layer, increase the de-intercalation rate of lithium ions, and improve the rapid charging performance of the single battery.

[0438] Exemplarily, the lithium-containing binder comprises lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, the lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer is derived from lithium acrylate monomers, acrylonitrile monomers, acrylamide monomers and hydroxyethyl acrylate monomers, and the molar ratio of the lithium acrylate monomers, the acrylonitrile monomers, the acrylamide monomers and the hydroxyethyl acrylate monomers is 30% to 50%: 15% to 45%: 5% to 20%: 20% to 35%. For example, the molar ratio of the lithium acrylate monomers, the acrylonitrile monomers, the acrylamide monomers and the hydroxyethyl acrylate monomers 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, improve the rapid charging performance of the single battery, and is not prone to swelling during charging and discharging, so that the structure is stable, and the cycle performance of the negative electrode film layer during rapid charging and discharging is improved.

[0440] In some other embodiments, in the case of adopting at least two film layers for the negative electrode film layer, the negative electrode film layer further comprises a lithium-containing binder.

[0441] Optionally, the first negative electrode film layer further comprises a first lithium-containing binder, and the second negative electrode film layer further comprises a second lithium-containing binder, and 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 a relatively large amount of freely movable lithium ions for the second negative electrode film layer, which can further improve the rapid charging performance of the single battery.

[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 formed by any two of the above values. The lithium element in the first lithium-containing binder can exist in the form of ions, which can increase the number of freely movable lithium ions in the negative electrode film layer, shorten the distance of lithium ion diffusion to the surface of the negative electrode film layer, improve the de-intercalation rate of lithium ions, and improve the rapid charging performance of the single battery.

[0444] Optionally, the mass content of lithium element in the first lithium-containing binder is 3% to 10%, which can be 3% to 8%. For example, the mass content of lithium element in the first lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range formed by any two of the above values. When the mass content of lithium element is in 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 of lithium ion diffusion to the surface of the negative electrode film layer, improve the deintercalation rate of lithium ions, and improve the rapid charging performance of the single battery.

[0445] For example, the first lithium-containing binder includes lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, which is derived from lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and hydroxyethyl acrylate monomer, and the molar ratio of lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and hydroxyethyl acrylate monomer is 30% to 50%: 15% to 45%: 5% to 20%: 20% to 35%. For example, the molar ratio of lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and 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, improve the rapid charging performance of the single battery, and is not prone to swelling during charging and discharging, has a stable structure, and improves the cycle performance of the negative electrode film layer during rapid charging and discharging.

[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%. For example, 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 formed by any two of the above values. The lithium element in the second lithium-containing binder can exist in the form of ions, which can increase the number of lithium ions that can freely move in the negative electrode film layer, shorten the distance of lithium ion diffusion to the surface of the negative electrode film layer, improve the deintercalation rate of lithium ions, and improve the rapid charging performance of the single battery.

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

[0449] Optionally, the mass content of lithium element in the second lithium-containing binder is 3% to 10%, optionally 3% to 8%. Illustratively, the mass content of lithium element in the second lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range formed by any two of the above values. When the mass content of lithium element is in 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 of lithium ion diffusion to the surface of the negative electrode film layer, improve the deintercalation rate of lithium ions, and improve the rapid charging performance of the single battery cell.

[0450] Illustratively, the second lithium-containing binder includes lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, the lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer is derived from lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and hydroxyethyl acrylate monomer, and the molar ratio of lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and hydroxyethyl acrylate monomer is 30% to 50%: 15% to 45%: 5% to 20%: 20% to 35%. For example, the molar ratio of lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and 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, improve the rapid charging performance of the single battery cell, and is not prone to swelling during charging and discharging, has a stable structure, and improves the cycle performance of the negative electrode film layer during rapid charging and discharging.

[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 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).

[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 further optionally comprises a negative electrode conductive agent. The present application does not have a particular limitation on the type of the negative electrode conductive agent, and as an example, the negative electrode conductive agent can comprise at least one of super-p carbon, conductive graphite, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the mass 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 further optionally comprises a negative electrode binder. In some embodiments, the mass content of the negative electrode binder is ≤5% based on the total weight of the negative electrode film layer.

[0456] In some embodiments, the negative electrode film layer further optionally comprises other auxiliary agents. As an example, the other auxiliary agents can comprise thickening agents, dispersing agents, and the like, such as sodium carboxymethyl cellulose (CMC-Na), PTC thermistor materials, and the like. In some embodiments, the mass content of the other auxiliary agents is ≤2% based on the total weight of the negative electrode film layer.

[0457] In some embodiments, the negative electrode current collector can employ a metal foil or a composite current collector. As an example of the metal foil, at least one foil of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy can be employed. The composite current collector can comprise a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material in the metal material layer can comprise at least one of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer can comprise 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 the single battery cell is 1.05 to 1.30, which can be optionally 1.07 to 1.15. As an 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 the single battery 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 between any two of the above 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 the single battery cell is within the above range, there are sufficient sites in the negative electrode film layer for lithium intercalation, which can reduce the risk of lithium precipitation and is conducive to fast charging.

[0460] In the embodiments of the present application, the CB value is of the meaning known in the art and can be detected by using the devices and methods known in the art, for example, the capacity of the unit area of the negative electrode film layer and the capacity of the 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, taking the battery charging upper limit voltage of 3.65V and the battery discharging cut-off voltage of 2.0V as examples,

[0462] The capacity of the unit area of the positive electrode film layer refers to the actual de-lithium 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 taken, and a CR2430 type half buckle battery of positive electrode-lithium sheet is assembled. The area of the positive electrode sheet used is a mm 2 , wherein the electrolyte is a solution of 1 mol / L LiPF 66 6 in EC / EMC / DEC=3 / 5 / 2 (mass ratio), and then the assembled half buckle battery is placed for 3h. The test is carried out at 25℃. The capacity of the unit area of the positive electrode film layer is calculated by using 0.1C to charge (Charge) de-lithium in the voltage interval 2.0V to 3.65V, and then using 0.05C to discharge (Discharge) lithium intercalation to 2.0V, and repeating the cycle 2 times. The discharge capacity of the second cycle is taken as Y mAh. The actual battery design positive electrode sheet length is b mm, the width is c mm, and the number of positive electrode active material coated on the positive electrode current collector is d. Then the capacity of the unit area of the positive electrode film layer is Y / (a*b*c*d).

[0463] Specifically, the capacity of the unit area of the negative electrode film layer refers to the actual lithium intercalation capacity of the negative electrode active material. The test method is as follows: the battery is disassembled in a PRS340 / 11-119-11 Braun glove box, the negative electrode sheet is taken, and a CR2430 type half buckle battery of negative electrode-lithium sheet is assembled. The area of the negative electrode sheet used is f mm 2² , wherein the electrolyte is a solution of 1 mol / L LiPF 66 6 in EC / EMC / DEC=3 / 5 / 2 (mass ratio), and then the assembled half buckle battery is placed for 3h. The test is carried out at 25℃. The capacity of the unit area of the positive electrode film layer is calculated by using 0.1C to charge (Charge) de-lithium in the voltage interval 2.0V to 3.65V, and then using 0.05C to discharge (Discharge) lithium intercalation to 2.0V, and repeating the cycle 2 times. The discharge capacity of the second cycle is taken as Y mAh. The actual battery design positive electrode sheet length is b mm, the width is c mm, and the number of positive electrode active material coated on the positive electrode current collector is d. Then the capacity of the unit area of the positive electrode film layer is Y / (a*b*c*d).

[0464] In some embodiments, the single-sided coating weight of the negative electrode film layer is 0.09g / 1540.25mm2 -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 to 150 mg / 1540.25 mm 2 . Illustratively, the single-sided coating weight of the negative electrode film layer is 90 mg / 1540.25 mm 2 , 92 mg / 1540.25 mm 2 , 95 mg / 1540.25 mm 2 , 96 mg / 1540.25 mm 2 , 100 mg / 1540.25 mm 2 , 102 mg / 1540.25 mm 2 , 104 mg / 1540.25 mm 2 , 105 mg / 1540.25 mm 2 , 108 mg / 1540.25 mm 2 , 110 mg / 1540.25 mm 2 , 112 mg / 1540.25 mm 2 , 114 mg / 1540.25 mm 2 , 115 mg / 1540.25 mm 2 , 116 mg / 1540.25 mm 2 , 118 mg / 1540.25 mm 2 , 120 mg / 1540.25 mm 2 , 122 mg / 1540.25 mm 2 , 125 mg / 1540.25 mm 2 , 128 mg / 1540.25 mm 2 , 130 mg / 1540.25 mm 2 , 132 mg / 1540.25 mm 2 , 135 mg / 1540.25 mm 2 , 137 mg / 1540.25 mm 2 , 140 mg / 1540.25 mm 2 , 142 mg / 1540.25 mm 2 , 145 mg / 1540.25 mm 2 , 148 mg / 1540.25 mm 2 , 150 mg / 1540.25 mm 2 , 152 mg / 1540.25 mm 2, 155 mg / 154 0.25 mm 2 , 160 mg / 154 0.25 mm 2 , 165 mg / 154 0.25 mm 2 , 170 mg / 154 0.25 mm 2 or a range between any two of the above values.

[0466] In the embodiments of the present application, the single-side coating weight of the negative electrode film layer is in the meaning known in the art, which can be detected by using the devices and methods known in the art, for example, the method for testing the single-side coating weight of the film layer.

[0467] When the single-side coating weight of the negative electrode film layer is in the above range, the heat generation per unit area of the negative electrode tab 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. For example, the thickness of the negative electrode current collector is 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm or a range between any two of the above values. In other examples, the thickness of the negative electrode current collector is 4 μm to 10 μm, and the thickness of the negative electrode current collector is 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or a range between any two of the above values. The negative electrode current collector can be copper.

[0469] When the thickness of the negative electrode current collector is in the above range, the flow capacity of the negative electrode current collector is excellent, and the energy density of the battery cell can be improved.

[0470] In the embodiments of the present application, the thickness of the negative electrode current collector is in the meaning known in the art, which can be detected by using the devices and methods known in the art, for example, the thickness of the negative electrode current collector can be measured by using a micrometer after the solvent is used to wash the film layer on the surface of the negative electrode current collector.

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

[0472] The negative electrode tab does not exclude other additional functional layers in addition to the negative electrode film layer. For example, in some embodiments, the negative electrode tab of the embodiments of the present application further comprises a negative electrode conductive layer arranged on the surface of the negative electrode current collector and sandwiched between the negative electrode current collector and the negative electrode film layer. In some other embodiments, the negative electrode tab of the embodiments of the present application further comprises a protective layer arranged on the surface of the negative electrode film layer.

[0473] In some embodiments, the negative electrode tab further comprises a negative electrode conductive layer between the negative electrode film layer and the negative electrode current collector. The negative electrode conductive layer can further improve the conductivity of the negative electrode tab, reduce the heat generation of the negative electrode tab, and thus reduce the heat generation of the single 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 defined by any two of the above values.

[0475] When the thickness of the negative electrode conductive layer is in the above range, the conductivity of the negative electrode tab can be further improved, the heat generation of the negative electrode tab can be reduced, and thus the heat generation of the single battery cell can be reduced, while the energy density of the single battery cell can be improved.

[0476] In the embodiments of the present application, the thickness of the negative electrode conductive layer has the meaning known in the art, can be detected by using the devices and methods known in the art, and can be detected by using the test method of the negative electrode conductive layer described above.

[0477] In some embodiments, the negative electrode conductive layer comprises 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, and thus improve the conductivity of the negative electrode tab and reduce the heat generation of the single battery cell. The negative electrode binder in the negative electrode conductive layer can improve the adhesion between the negative electrode current collector and the negative electrode film layer, and thus improve the structural stability of the negative electrode tab.

[0478] In some embodiments, the negative electrode conductive layer can further optionally comprise other auxiliary agents. For example, the other auxiliary agents can comprise thickening agents, such as 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%. For example, the mass content of the negative electrode conductive agent is 20%, 25%, 30%, 35%, 40%, or a range defined by any two of the above values.

[0480] For example, the negative electrode conductive agent comprises 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%. For example, the mass content of the negative electrode binder is 60%, 65%, 70%, 75%, 80%, or a range defined by any two of the above values.

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

[0483] [Positive electrode sheet]

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

[0485] In other examples, the positive electrode sheet has a resistance 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 positive film layer of the single battery cell has a compacted density of, but not limited to, 2.5 g / cm 3 -2.8 g / cm 3 , optionally 2.55 g / cm 3 -2.70 g / cm 3 , at 100% state of charge SOC. Exemplarily, the positive film layer of the single battery cell has a compacted density of 2.2 g / cm 3 , 2.50 g / cm 3 , 2.52 g / cm 3 , 2.55 g / cm 3 , 2.56 g / cm 3 , 2.57 g / cm 3 , 2.58 g / cm 3 , 2.60 g / cm 3 , 2.62 g / cm 3 , 2.65 g / cm 3 , 2.68 g / cm 3 , 2.70 g / cm 3 , 2.72 g / cm3 2.75 g / cm3 3 2.78 g / cm3 3 2.80 g / cm3 3 or a range consisting of any two of the aforementioned values.

[0488] The compaction density of the positive electrode film layer in the above range is conducive to improving the energy density of the single battery cell, and because the positive electrode active material in the positive electrode film layer is more tightly packed, the contact resistance between particles is smaller, which can further reduce the resistance of the pole piece, thereby reducing the heat generation under fast charging. Therefore, by adjusting the compaction density of the positive electrode film layer to a reasonable range, the single battery cell has high energy density and high charging rate performance.

[0489] Optionally, the powder compaction density of the positive electrode active material under 30000N is 2.46 g / cm3 3 2.8 g / cm3 3 . For example, the powder compaction density of the positive electrode active material under 30000N is 2.46 g / cm3 3 2.47 g / cm3 3 2.48 g / cm3 3 2.49 g / cm3 3 2.5 g / cm3 3 2.51 g / cm3 3 2.55 g / cm3 3 2.58 g / cm3 3 2.60 g / cm3 3 2.65 g / cm3 3 2.68 g / cm3 3 2.70 g / cm3 3 2.72 g / cm3 3 2.75 g / cm3 3 2.78 g / cm3 3 2.80 g / cm3 3 or a range consisting of any two of the aforementioned values.

[0490] The powder compaction density of the positive electrode active material under 30000N in the above range can improve the energy density of the single battery cell, and because the positive electrode active material in the positive electrode film layer can be more tightly packed, the contact resistance between particles is smaller, which can further reduce the resistance of the pole piece, thereby reducing the heat generation.

[0491] In the embodiments of the present application, the powder compaction density of the material is the meaning known in the art, which can be detected by the methods and devices known in the art according to the test standard GB / T24533-2009. For example, a certain amount of the positive active material is taken as a sample, which is added into a mold with a bottom area of 1.327 cm2 of a UTM7305 type electronic pressure testing machine, and is pressed to 3000 kg (equivalent to 30000 N), and is kept for 30 s, then is unloaded, and is kept for 10 s, then the powder compaction density of the positive active material under the action of 30000 N is recorded and calculated. 2

[0492] In some embodiments, the single-side coating weight of the positive electrode film layer is 0.2 g / 1540.25 mm 2 to 0.37 g / 1540.25 mm 2 , which can be 240 mg / 1540.25 mm 2 to 330 mg / 1540.25 mm 2 . Exemplarily, the single-side coating weight of the positive electrode film layer is 200 mg / 1540.25 mm 2 , 210 mg / 1540.25 mm 2 , 220 mg / 1540.25 mm 2 , 230 mg / 1540.25 mm 2 , 240 mg / 1540.25 mm 2 , 250 mg / 1540.25 mm 2 , 260 mg / 1540.25 mm 2 , 270 mg / 1540.25 mm 2 , 280 mg / 1540.25 mm 2 , 290 mg / 1540.25 mm 2 , 300 mg / 1540.25 mm 2 , 310 mg / 1540.25 mm 2 , 320 mg / 1540.25 mm 2 , 330 mg / 1540.25 mm 2 , 340 mg / 1540.25 mm 2 , 350 mg / 1540.25 mm 2 , 360 mg / 1540.25 mm 2 , 370 mg / 1540.25 mm 2 or a range composed of any two of the above values.

[0493] ​When the single-sided coating weight of the positive electrode film is within the above range, the heat generation per unit area of ​​the positive electrode sheet will not be too large, and it can also improve the energy density and charging rate performance of the single cell.

[0494] In this embodiment, the compaction density of the positive electrode film layer of a single battery cell at 100% State of Charge (SOC) can be detected by the following method: The positive electrode sheet of the single battery cell at 100% 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 it is a double-sided coated sheet, the positive electrode film layer on one side can be wiped off first) is cut into a small circular piece with an area of ​​S1, its weight is weighed and recorded as M1, and its thickness H1 is measured. Then, the positive electrode film layer of the weighed positive electrode sheet is wiped off, 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 = (weight of the positive electrode sheet M1 - weight of the positive current collector M0) / S1, the thickness of the positive electrode film = the thickness of the positive electrode sheet H1 - the thickness of the positive current collector H0, and the compaction density of the positive electrode film = the single-sided coating weight of the positive electrode film / the thickness of the positive electrode film.

[0495] In some embodiments, the thickness of the positive electrode current collector is 10 μm-15 μm, optionally 12 μm to 15 μm. Exemplarily, the thickness of the positive electrode current collector is 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, or a range consisting of any two of the above values.

[0496] The positive current collector can be aluminum.

[0497] When the thickness of the positive current collector is within the above range, the current carrying capacity of the positive current collector is excellent, and it can enable the single cell to have a high energy density.

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

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

[0500] The positive electrode tab does not exclude other additional functional layers besides the positive electrode film layer. For example, in some embodiments, the positive electrode tab of the embodiments of the present application further comprises a positive electrode conductive layer sandwiched between the positive electrode current collector and the positive electrode film layer, arranged on the surface of the positive electrode current collector. In some other embodiments, the positive electrode tab of the embodiments of the present application further comprises 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 single-sided positive electrode film layer is 0.05 to 0.3. Illustratively, the ratio of the thickness of the positive electrode current collector to the thickness of the single-sided positive electrode film layer is 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, or a range formed by 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 rapid 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. Illustratively, the powder resistivity of the positive electrode active material can be 27.5 Ω•cm, 20 Ω•cm, 19 Ω•cm, 18 Ω•cm, 17 Ω•cm, 16 Ω•cm, 15 Ω•cm, 14 Ω•cm, 13 Ω•cm, 12 Ω•cm, 11 Ω•cm, 10 Ω•cm, 9 Ω•cm, 8 Ω•cm, 7 Ω•cm, 6 Ω•cm, 5 Ω•cm, 4 Ω•cm, 3 Ω•cm, 2 Ω•cm, 1 Ω•cm, or a range formed by any two of the above values.

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

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

[0506] In some embodiments, the cathode active material has a charge gram capacity at 0.1C rate of 150 mAh / g to 170 mAh / g, optionally 157 mAh / g to 170 mAh / g. Illustratively, the cathode active material has a charge gram capacity at 0.1C rate 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 defined by any two of the foregoing values.

[0507] When the cathode active material has a charge gram capacity at 0.1C rate in the above range, the energy density of the single battery cell is relatively high.

[0508] In the embodiments of the present application, the gram capacity of the active material has the meaning known in the art and can be tested using devices and methods 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. A half-buckle type battery is assembled using lithium metal as the negative electrode and the sample tab containing the above material as the positive electrode. The half-buckle type battery is tested on a battery tester or other equivalent performance testing device at 23°C ± 2°C. The discharge capacity is obtained by 0.1C rate charging and discharging, and then the capacity is divided by the mass of the active material of the tab to obtain the charge gram capacity parameter.

[0509] In some embodiments, the cathode active material includes a lithium-containing phosphate, and the lithium-containing phosphate 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 of C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0510] The phosphate particles coated with the coating layer on the surface can improve the electrical conductivity of the lithium-containing phosphate with an olivine structure, reduce the powder resistivity of the material, and be beneficial to improving the migration rate of lithium ions, improving the rapid charging capacity of the battery, and reducing the heat generation of the single battery cell.

[0511] The mass ratio of the olivine-structured lithium-containing phosphate in the positive electrode active material can be greater than or equal to 80% and less than or equal to 100%. It can be considered that the positive electrode active material of the present application is an olivine-structured lithium-containing phosphate system. When the mass ratio of the olivine-structured lithium-containing phosphate is less than 100%, the positive electrode active material can also include commonly used positive electrode active materials, for example, 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 ratio of the olivine-structured lithium-containing phosphate in the positive electrode active material is 100%.

[0513] In some embodiments, the phosphate particles include a compound of the general formula Li x1 A y1 Me a M b P 1-c X c Y z , 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 includes one or more of Na, K, Mg, Me includes one or more of Mn, Fe, Co, Ni, M includes one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, Ce, X includes one or more of S, Si, Cl, B, C, N, and Y includes one or more of O, F. The cycle stability of the phosphate particles is relatively excellent, which is beneficial to improve the cycle performance of the single battery cell.

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

[0515] Exemplarily, the phosphate particles include one or more of LiFePO4, LiMnPO4, LiNiPO4, LiCoPO4. During the charging and discharging process, the single battery cell will be accompanied by the deintercalation and consumption of active ions such as Li, and the molar content of Li is different when the single battery cell is discharged to different states. In the enumeration of the positive 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, and the positive active material is applied to the battery system. After charging and discharging cycle, the molar content of Li may change. In the enumeration of the positive active materials LiFePO4, LiMnPO4, LiNiPO4, LiCoPO4, etc. in the embodiments of the present application, the molar content of oxygen O is only the theoretical state value, and the release of oxygen from the lattice will cause the molar content of oxygen O to change. In fact, the molar content of oxygen O will appear to float, and the above-mentioned situations are all within the protection scope of the present application.

[0516] In some embodiments, the coating layer includes a fast ion conductor of the general formula Li 3-d Fe 2-d M 2d (PO x2 ) y2 , M2 includes one or more elements of Ti, Zr, Hf, Ge, and Sn, 0≤d≤1, 0

[0517] Exemplarily, the fast ion conductor is a material with a NASICON structure, for example, including one or more of lithium iron titanium phosphate Li2FeTi(PO4)3, lithium iron zirconium phosphate Li2FeZr(PO4)3, lithium iron tin phosphate Li2FeSn(PO4)3.

[0518] The fast ion conductor with a NASICON structure is a material with super-fast ion conduction ability, which has abundant three-dimensional lithium ion diffusion and transmission channels, and has the advantages of high ion conduction efficiency and strong structural stability in multiple delithiation and lithium intercalation processes. Coating the surface of the phosphate particles with a fast ion conductor containing a NASICON structure can significantly improve the transmission rate of lithium ions in the positive electrode during multiple delithiation and lithium intercalation, improve the ion conductivity of the positive active material, and improve the rapid charging capacity of the single battery cell. In addition, it can also improve the specific capacity and the energy density of the corresponding single battery cell.

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

[0520] The carbon element and the fast ion conductor can be arranged in layers, for example, the carbon element as an independent carbon coating layer and the fast ion conductor 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 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 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, the carbon coating layer can be coated on the surface of the fast ion conductor layer by a carbonization process of an organic carbon source (for example, glucose, polyethylene glycol, etc.). The carbon coating layer can partially coat the fast ion conductor layer or completely coat the fast ion conductor layer. The arrangement of the carbon coating layer can significantly improve the electronic conductivity of the phosphate particles, compensate for the poor electronic conductivity of the phosphate particles, and improve the energy density of the single battery.

[0522] Specifically, the arrangement of the carbon coating layer has the following advantages for the positive electrode active material of the application:

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

[0524] The carbon coating layer of the positive electrode active material of the application has a loose and porous structure, which enables the electrolyte to fully and effectively contact the lithium-containing phosphate, thereby improving the transmission rate of lithium ions at the phase interface and the charging capacity of the single battery.

[0525] Coating a carbon coating layer on the surface of the lithium-containing phosphate not only improves the electronic conductivity of the lithium-containing phosphate, but also improves the structural stability of the positive electrode active material, effectively alleviates the iron dissolution phenomenon of the positive electrode active material during long-term storage and cyclic use of the single battery, and thus improves the cycle life of the single battery.

[0526] The positive electrode active material of the application uses lithium-containing phosphate as a substrate, fully utilizes the advantages of low cost, high reliability, and good cycle stability of lithium-containing phosphate, and solves the disadvantages of poor electronic conductivity and ionic conductivity by using the coating layer (fast ion conductor layer and carbon coating layer). The single battery prepared from the positive electrode active material of the application can improve the energy density of the single battery under the premise of excellent cycle performance.

[0527] In the embodiments of the present application, the content of elements in the positive electrode active material is in the meaning known in the art, which can be detected by using the devices and methods known in the art, for example, referring to EPA 6010D-2014, tested by inductively coupled plasma atomic emission spectrometry, and determined by plasma atomic emission (ICP-OES, instrument model: Thermo ICAP7400). After disassembling the positive electrode sheet from the single battery cell discharged to 0% state of charge SOC, washing and drying with DMC, and removing impurities by high-temperature calcination, 0.4g of the positive electrode active material is weighed, 10ml (50% concentration) aqua regia is added thereto. Then it is placed on a 180°C flat plate for 30min. After digestion on the flat plate, it is diluted to a volume of 100ml, and the quantitative test is performed by the standard curve method.

[0528] In some embodiments, the graphitization degree of the positive electrode active material is 0.15 to 0.32, which can be 0.19 to 0.26. Illustratively, the graphitization degree of the positive electrode active material is 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, or a range consisting of any two of the above values.

[0529] When the graphitization degree of the positive electrode active material is in the above range, it is beneficial to improve the conductivity of the positive electrode active material and reduce the heat generation of the positive electrode sheet, thereby reducing the heat generation of the single battery cell.

[0530] In the embodiments of the present application, the higher the graphitization degree of the material, the lower the degree of disorder, which can be tested according to the test standard JIS / K 0131-1996 "General method for X-ray diffraction analysis".

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

[0532] Alternatively, the mass content of carbon element in the olivine-structured lithium-containing phosphate is 1% to 2%, and the specific surface area of the olivine-structured lithium-containing phosphate is 7.5m 2 / g to 14m 2 / g.

[0533] Illustratively, the mass content of carbon element 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 olivine-structured phosphate 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 formed by any two of the above values.

[0535] The carbon element mainly exists in the material in the form of a carbon coating layer, the carbon coating layer is loose and porous, which is beneficial to improve the specific surface area of the material, and is more beneficial to the effective contact between the electrolyte and the phosphate particles and the transmission of lithium ions at the phase interface. In addition, when the mass content of the carbon element is in the above range, the conductivity of the lithium-containing olivine-structured phosphate can be significantly improved, which is beneficial to improve the ionic conductivity and electronic conductivity of the lithium-containing olivine-structured phosphate, and can improve the rapid charging capacity and energy density of the single battery cell.

[0536] In the embodiments of the present application, the specific surface area of the material has the meaning known in the art and can be detected by using the devices and methods known in the art, for example, according to the test standard GB / T 19587-2017, taking the positive active material as a sample, and using the Tri-Star 3020 type specific surface area pore size analyzer of the Micromeritics company of the United States to test the specific surface area.

[0537] In some embodiments, the volume distribution particle size of the positive active material satisfies: 1µm≤Dv50≤2µm, 0.4µm≤Dv10≤0.7µm.

[0538] For example, the Dv50 of the positive 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 formed by any two of the above values.

[0539] Exemplarily, the Dv10 of the positive electrode active material can 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 formed by any two of the above values.

[0540] The particle size of the positive electrode active material is relatively small, the path of lithium ion deintercalation in the positive electrode active material is short, and the heat production is less. Moreover, the particle size of the positive electrode active material is not too small, and agglomeration basically does not occur in the process of preparation, so that the performance of the positive electrode active material is stable.

[0541] In the embodiments of the present application, the volume average particle size Dv50 of the material refers to the particle size corresponding to 50% in the volume distribution, and the volume average particle size Dv10 of the material refers to the particle size corresponding to 10% in the volume distribution. The detection can be performed by using devices and methods known in the art. For example, the positive electrode active material is taken as a sample, 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 with 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 lithium-containing phosphate with olivine structure is in a particulate form, the lithium-containing phosphate with olivine structure includes secondary particles, the secondary particles include a plurality of primary particles, and the average particle size of the primary particles is 200 nm to 500 nm. Exemplarily, the average particle size of the primary particles is 200 nm, 220 nm, 250 nm, 280 nm, 300 nm, 320 nm, 350 nm, 380 nm, 400 nm, 420 nm, 450 nm, 480 nm, 500 nm, or a range formed by any two of the above values.

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

[0545] In the embodiments of the present application, the secondary particle refers to an agglomerated particle formed by aggregation of two or more primary particles. The primary particles and the 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 SEM image testing. The SEM test parameters can be set as follows: working voltage (EHT) is 10.00 kV, InLens detector is used, working distance is 4.6 mm, and magnification is 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 metavanadate, lithium tartrate, lithium citrate, lithium nickelate, and lithium ferrite. The above-mentioned materials can act as a lithium supplement, which can supplement lithium ions for the positive electrode film layer, make up for the irreversible loss of lithium ions in the system, and improve the capacity, thereby improving the energy density of the single cell.

[0547] Optionally, the ternary material comprises 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 comprises one or more of Na, K, Mg, M3 comprises 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, Ce, and Y3 comprises one or more of O, F.

[0548] Exemplarily, the ternary material comprises LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (NCM523), LiNi 0.6 Co 0.2 Mn 0.2 O2 (NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (NCM811), LiNi 0.80 Co 0.15 Al 0.05 O2.

[0549] In some embodiments, the mass content of the lithium supplement in the positive electrode film layer is 0.5% to 5%, for example, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a range between any two of the foregoing values. When the mass content of the lithium supplement is within the foregoing range, the lithium supplement can supplement lithium ions to the positive electrode film layer, compensate for the irreversible loss of lithium ions in the system, and improve the capacity, thereby improving the energy density of the single battery cell.

[0550] The lithium supplement can be in the same layer as the positive electrode active material, or in different layers. When the lithium supplement and the positive electrode active material are in different layers, the lithium supplement can be in a lithium supplement layer, and the positive electrode active material can be in a positive electrode active material layer, in other words, the positive electrode film layer includes the lithium supplement layer and the positive electrode active material layer. The positive electrode active material layer can be disposed on at least one side of the positive electrode current collector, and the lithium supplement layer can be between the positive electrode active material layer and the positive electrode current collector. Alternatively, the lithium supplement layer can be disposed on at least one side of the positive electrode current collector, and the positive electrode active material layer can be between the lithium supplement layer and the positive electrode current collector. Alternatively, the lithium supplement layer can be between the positive electrode active material layer and the positive electrode current collector, and the lithium supplement in the lithium supplement layer can be gradually released into the system during the cyclic charging and discharging of the single battery cell, thereby compensating for the loss of lithium in the battery system.

[0551] In some embodiments, the positive electrode film layer optionally further includes a positive electrode conductive agent. The type of positive electrode conductive agent is not particularly limited in the embodiments of the present application, and as an example, the positive electrode conductive agent includes at least one of super conductive 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 optionally further includes a positive electrode binder. The type of positive electrode binder is not particularly limited in the embodiments of the present application, and as an example, the positive electrode binder can include at least one of polyvinylidene fluoride, polytetrafluoroethylene, a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, polyacrylic acid, and a fluorine-containing acrylic ester resin. In some embodiments, the mass content of the positive electrode binder is ≤5% based on the mass of the positive electrode film layer.

[0554] In some embodiments, the positive current collector can employ a metal foil or a composite current collector. As an example of the metal foil, at least one of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy can be employed. The composite current collector can include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material of the metal material layer can include at least one of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy. As an example, the polymer material base layer can 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 tab further includes a positive conductive layer between the positive film layer and the positive current collector. The positive conductive layer can further improve the conductivity of the positive electrode tab, reduce the heat generation of the positive electrode tab, and thus reduce the heat generation of the single battery cell.

[0556] In some embodiments, the positive conductive layer has a thickness of 0.5 μm to 2 μm. For example, the positive conductive layer has a thickness of 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 defined by any two of the above values.

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

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

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

[0560] Optionally, the positive conductive agent has a mass content of 30% to 50% in the positive conductive layer. For example, the positive conductive agent has a mass content of 30%, 35%, 40%, 45%, 50%, or a range defined by any two of the above values.

[0561] For example, the positive 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 conductive agent in the positive conductive layer can improve the conductivity of the positive conductive layer, and thus improve the conductivity of the positive electrode tab and reduce 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%. Illustratively, the mass content of the positive electrode binder is 50%, 60%, 65%, 70%, or a range composed 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, a polyacrylic acid, and a fluorine-containing acrylic ester resin. The positive electrode binder in the positive electrode conductive layer can improve the adhesion between the positive electrode current collector and the positive electrode film layer, and improve the structural stability of the positive electrode sheet.

[0564] [Separator film]

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

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

[0567] In the embodiments of the present application, the porosity refers to the percentage of the volume of the pores in the separator film to the total volume of the separator film. The porosity can be tested in accordance with the standard GB / T36363-2018 “Polyolefin Separator for Single Battery Cell”. It should be noted that, in the actual testing process, the testing process can be slightly different from the standard in order to eliminate the influence on the testing of the porosity as much as possible, and to obtain more accurate test values.

[0568] In some embodiments, the thickness of the base film can be, but is not limited to, 6 μm to 12 μm, optionally 6 μm to 9 μm. Illustratively, 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 composed of any two of the above values.

[0569] Optionally, the material of the base film can be polypropylene.

[0570] When the thickness of the base film is in the above range, the migration path of lithium ions in the base film is shorter, and the internal resistance of the single battery can be further reduced, thereby reducing the heat generation.

[0571] In the embodiments of the present application, the separator film can be a base film, and the separator film optionally further comprises a functional layer disposed on at least one side of the base film, and the functional layer can comprise inorganic particles to improve the heat resistance of the separator film. Optionally, the functional layer is disposed on both sides of the base film.

[0572] In some embodiments, the functional layer comprises a first functional layer and a second functional layer, the first functional layer is disposed on one side of the base film, the first functional layer comprises first inorganic particles, the second functional layer is disposed on the other side of the base film, and the second functional layer comprises composite particles, the composite particles comprise second inorganic particles and a plurality of 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 separator film.

[0574] Optionally, the first functional layer can comprise a binder, and the binder can comprise at least one of a fluorine-containing binder or a polyacrylic acid binder, for example, polyvinylidene fluoride.

[0575] Optionally, the first inorganic particles comprise one or more of silicon oxide, aluminum oxide, boehmite, barium sulfate, calcium oxide, titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, and tin oxide. The above first inorganic particles can improve the heat resistance of the first functional layer.

[0576] In the embodiments of the present application, the thickness of the base film has the meaning known in the art, and can be detected by methods and devices known in the art. For example, a newly prepared separator film can be taken as a sample, or a single battery that has been fully discharged (discharged to the lower limit cutoff voltage so that the charged state of the battery is about 0% SOC) can be disassembled in reverse, the separator film is obtained from the single battery, and the separator film is dried as a sample. The separator film is cut by an ion beam cutting instrument to form a cross section, and then the thickness of the cross section of the separator film and each layer thereof is measured by a scanning electron microscope.

[0577] The non-fluoropolymer particles in the second functional layer refer to polymers that are non-fluorinated polymers. For example, the non-fluoropolymer particles comprise an acrylate copolymer, and the acrylate copolymer comprises an acrylate-acrylonitrile-acrylamide-acryl copolymer. The acrylate copolymer has excellent bonding performance, and has high bonding stability with the base film. The molar ratio of each monomer in the copolymer can be any ratio, for example, the molar ratio is 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 high-temperature treatment in the granulation process, so that the composite particles have pores, which is beneficial to the transmission of lithium ions, improves the ion conductivity of the isolation film, and the second inorganic particles can also improve the compression modulus of the composite particles. In the charging and discharging process, the composite particles are less likely to deform, making the structure of the isolation film more stable, which can improve the kinetic performance of the single cell and improve the rapid charging performance. Optionally, compared with the first functional layer, the second functional layer is arranged close to the negative electrode plate. Due to the fact that the composite particles are less likely to deform, the isolation film is less likely to cause side effects such as extrusion to the negative electrode plate, so that the kinetic performance of the negative electrode plate is stable. Correspondingly, the first functional layer is arranged close to the positive electrode plate.

[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. The above-mentioned second inorganic particles can improve the heat resistance of the second functional layer, and can form composite particles with non-fluoropolymers, further improving the cycle stability and kinetic performance of the isolation film, and improving the cycle performance and rapid charging performance of the single cell.

[0580] The average particle size of the second inorganic particles is 5 nm to 100 nm, optionally 10 nm to 100 nm, and optionally 5 nm to 20 nm. Illustratively, the average particle size of the second inorganic particles is 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or a range composed of any two of the above values. When the average particle size of the second inorganic particles is in the above range, it is beneficial to improve the heat resistance and compression modulus of the composite particles.

[0581] In the embodiments of the present application, the average particle size of the second inorganic particles has the meaning known in the art and can be detected by using devices and methods known in the art. For example, after obtaining the isolation film, the isolation film is dried as a sample, the isolation film is cut off using an ion beam cutter to form a cross section, and then the particle size of the second inorganic particles in the isolation film is measured using a scanning electron microscope. The particle sizes of a plurality of, for example, 50, second inorganic particles are measured, and the average value thereof is calculated as the average particle size of the second inorganic particles.

[0582] In some embodiments, the ion conductivity of the separation membrane is 0.3 mS / cm to 0.6 mS / cm. Exemplarily, the ion conductivity of the separation membrane is 0.3 mS / cm, 0.35 mS / cm, 0.4 mS / cm, 0.45 mS / cm, 0.5 mS / cm, 0.55 mS / cm, 0.6 mS / cm, or a range defined by any two of the above values.

[0583] When the ion conductivity of the separation membrane is in the above range, the migration ability of the separation membrane to lithium ions can be further improved, and the rapid charging performance of the single battery cell can be improved.

[0584] In the embodiments of the present application, the ion conductivity of the separation membrane is the meaning known in the art, which can be detected by using the devices and methods known in the art, for example,

[0585] Preparation of 2025 type button cell for testing: in a vacuum glove box, lithium sheet was put into the negative electrode shell, 150 μL of electrolyte was added, the electrolyte was a solution of 1 mol / L LiPF6 in EC / EMC / DEC=3 / 5 / 2 (mass ratio), and then the separation membrane (area of 3.14 cm 2 , thickness of 12 μm) was put to make it close to the lithium sheet, 25 μL of electrolyte was added, and finally the positive electrode sheet (the positive electrode sheet can be the positive electrode sheet in Example 1) was placed thereon, and then it was packaged. The assembled button cell was taken out of the vacuum glove box and placed for 24 h for the next test.

[0586] Test: in an electrochemical workstation, the test was carried out in the frequency range of 10 -1 ~ 10 6 Hz, the resistance Rb of the separation membrane was obtained, and the ion conductivity σ (unit: mS / cm) was calculated by the following formula,

[0587] σ = L / (R b × S)

[0588] Wherein, R b is the resistance of the separation membrane, and L and S are the thickness and area of the separation membrane to be tested, respectively.

[0589] In some embodiments, the base film comprises at least one of glass fiber, non-woven fabric, and polyolefin. The base film can be a single-layer film or a multi-layer composite film, and is not particularly limited. When the base film is a multi-layer composite film, the materials of the layers can be the same or different, and are not particularly limited.

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

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

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

[0593] In some embodiments, the single battery cell 7 can include a shell 20.

[0594] In some embodiments, the shell 20 of the single battery cell 7 can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, and the like. The shell 20 of the single battery cell 7 can also be a soft package, such as a pouch soft package. The material of the soft package can be plastic, such as at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

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

[0596] The preparation method of the single battery cell 7 of the embodiments of the present application is known. In some embodiments, the positive electrode tab, the separator film, the negative electrode tab, and the electrolyte can be assembled to form the single battery cell 7. As an example, the positive electrode tab, the separator film, the negative electrode tab can be formed into the electrode assembly 10 through a winding process and / or a stacking process, the electrode assembly 10 is placed in the shell 20, the electrolyte is injected after drying, and the single battery cell 7 is obtained through processes such as vacuum packaging, standing, formation, shaping, and the like.

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

[0598] The shape of the shell body 21 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cylindrical structure, a cylindrical shell body can be selected, and if the electrode assembly 10 is a cuboid structure, a cuboid shell body can be selected. Alternatively, the electrode assembly 10 and the shell body 21 are both cuboid structures.

[0599] In some embodiments, the material of the shell body 21 includes steel, which has high mechanical strength and is not easy to deform, and can improve the use reliability and cycle performance of the single battery cell. Alternatively, the mass ratio of steel in the shell body 21 is the highest.

[0600] Optionally, the thickness of the shell 21 is 0.1mm to 0.5mm, optionally 0.2mm to 0.35mm. For example, 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 between 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 high, which can improve the use reliability and cycle performance of the single battery cell 7, and the shell 21 occupies less space, and the internal space of the shell 21 is larger, which is beneficial to improve 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 part 12, a first tab 11 and a second tab 13, the first tab 11 and the second tab 13 protrude from the main body part 12. The first tab 11 is a part of the first tab that is not coated with an active material layer, and the second tab 13 is a part of the second tab that is not coated with an active material layer. The first tab 11 and the second tab 13 are used to lead out the current in the main body part 12. The polarity of the first tab and the second tab is opposite, that is, one of the first tab and the second tab is a positive electrode tab, and the other of the first tab and the second tab is a negative electrode tab. Of course, the first tab 11 can be a positive electrode tab, and the second tab 13 can be a negative electrode tab.

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

[0603] The first tab 11 and the second tab 13 can protrude from the same side of the main body part 12, or can extend from opposite sides respectively.

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

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

[0606] In some embodiments, the single battery cell 7 further comprises a first electrode terminal 31 electrically connected with 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 can be connected through an adapter or without an adapter. Optionally, the first electrode terminal 31 and the first tab 11 are directly welded without an adapter, which can reduce the resistance at the connection and is conducive to reducing the overall internal resistance of the single battery cell 7.

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

[0608] In some embodiments, the single battery cell 7 further comprises a second electrode terminal 32 electrically connected with 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 through an adapter or without an adapter. Optionally, the second electrode terminal 32 and the second tab 13 are directly welded without an adapter, which can reduce the resistance at the connection and is conducive to reducing the overall internal resistance of the single battery cell 7.

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

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

[0611] Further optionally, the overcurrent area of the single-side first electrode terminal 31 is 150mm 2 to 1000mm 2 , and can be 200mm 2 to 1000mm 2 The overcurrent area of the single-side first electrode terminal 31 refers to the sum of the overcurrent areas of all the first electrode terminals 31 on the same side of the main body 12. The overcurrent area of the 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 cover 22.

[0612] For example, the overcurrent area of the single-side first electrode terminal 31 can be 150mm 2 , 200mm 2 , 210mm 2 , 250mm 2, 280mm 2 , 300mm 2 , 320mm 2 , 350mm 2 , 380mm 2 , 400mm 2 , 450mm 2 , 500mm 2 , 550mm 2 , 600mm 2 , 650mm 2 , 700mm 2 , 750mm 2 , 800mm 2 , 850mm 2 , 900mm 2 , 950mm 2 , 1000mm 2 or a range between any two of the above values.

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

[0614] Further optionally, the overcurrent area of the single-side second electrode terminals 32 is 150mm 2 to 1000mm 2 , and optionally 200mm 2 to 1000mm 2 . The overcurrent area of the single-side second electrode terminals 32 refers to the sum of the overcurrent areas of all the second electrode terminals 32 located on the same side of the main body portion 12. The overcurrent area of the second electrode terminals 32 can be understood as the cross-sectional area of the second electrode terminals 32, which is perpendicular to the thickness direction of the end cover 22.

[0615] Exemplarily, the overcurrent area of the single-side second electrode terminals 32 can be 150mm 2 , 200mm 2 , 210mm 2 , 250mm 2 , 280mm 2 , 300mm 2 , 320mm 2 , 350mm 2 , 380mm 2 , 400mm 2 , 450mm 2 , 500mm 2 , 550mm 2 , 600mm 2 , 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 this application, the individual battery cell 7 according to the embodiments of this application can be assembled into a battery module 6. The number of individual battery 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 individual battery cells 7, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple individual battery cells 7 are connected in both series and parallel configurations. Multiple individual battery cells 7 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of these cells 7 is housed within the housing of the battery module 6. Alternatively, multiple individual battery cells 7 can first be connected in series, parallel, or in a mixed configuration to form the battery module 6, and then the multiple battery modules 6 can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing. Optionally, the battery module 6 may also include a housing with a accommodating space, within which multiple individual battery cells 7 are housed.

[0618] like Figure 26 As shown, in some embodiments, the battery module 6 can also be assembled into a battery pack 2, and 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 either 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, and the housing 5 has a receiving space 5c. The first housing portion 5a is used to cover the second housing portion 5b and form a closed space for accommodating the battery modules 6. The plurality of battery modules 6 can be arranged in the housing 5 in any manner.

[0620] The first box body part 5a and the second box body part 5b are mutually covered, and the first box body part 5a and the second box body part 5b jointly define a containing space 5c for containing single batteries. The second box body part 5b can be a hollow structure with one end open, and the first box body part 5a is a plate-shaped structure, which covers the open side of the second box body part 5b to form a box 5 with a containing space 5c. The first box body part 5a and the second box body part 5b can also be hollow structures with one side open, and the open side of the first box body part 5a covers the open side of the second box body part 5b to form a box 5 with a containing space 5c. Of course, the first box body part 5a and the second box body part 5b can be various shapes, such as a cylinder, a cuboid, etc.

[0621] In order to improve the sealing performance of the first box body part 5a and the second box body part 5b after being connected, a sealing member such as sealing glue, sealing ring, etc. can be arranged between the first box body part 5a and the second box body part 5b.

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

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

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

[0625] In some embodiments, during the charging process of the battery pack 2 or any single battery constituting the battery pack 2 from 10% state of charge to 80% state of charge, a plurality of charging steps are included, and the difference between the maximum state of charge of any charging step in the plurality of charging steps and the maximum state of charge of its adjacent charging step is less than or equal to 5% state of charge, such as 1% state of charge, 1.5% state of charge, 2% state of charge, 2.5% state of charge, 3% state of charge, 3.5% state of charge, 4% state of charge, 4.5% state of charge, 5% state of charge, or a range composed 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 10% state of charge to 40% state of charge, for any charging step, the charging rate can be any value between 5C to 10C, each charging step corresponding charging rate 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 between 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, for any charging step, the charging rate 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 charging to 80% state of charge is any value between 2.5C to 5C, for example, it can be 2.7C.

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

[0629] charging from 10% SOC to 15% SOC at 5.0C constant current,

[0630] charging from 15% SOC to 20% SOC at 5.0C constant current,

[0631] charging from 20% SOC to 25% SOC at 5.0C constant current,

[0632] charging from 25% SOC to 30% SOC at 5.0C constant current,

[0633] charging from 30% SOC to 35% SOC at 5.0C constant current,

[0634] charging from 35% SOC to 40% SOC at 5.0C constant current,

[0635] charging from 40% SOC to 45% SOC at 4.6C constant current,

[0636] charging from 45% SOC to 50% SOC at 4.3C constant current,

[0637] charging from 50% SOC to 55% SOC at 4.0C constant current,

[0638] charging from 55% SOC to 60% SOC at 3.7C constant current,

[0639] charging from 60% SOC to 65% SOC at 3.4C constant current,

[0640] charging 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 battery pack 2 or any single cell constituting the battery pack 2 has a charging time from 10% state of charge to 80% state of charge less than or equal to 10.5 min, optionally 5 min to 10.5 min, and the battery pack 2 is at room temperature, for example 30°C, at 10% state of charge. Illustratively, the battery pack 2 has a charging time from 10% state of charge to 80% state of charge of 10.5 min, 10 min, 9.5 min, 9 min, 8.5 min, 8 min, 7.5 min, 7 min, 6.5 min, 6 min, 5.5 min, 5 min, or a range consisting of any two of the above values.

[0644] In some embodiments, the single cell has a volumetric energy density of, but not limited to, 390 Wh / L to 500 Wh / L, optionally 410 Wh / L to 470 Wh / L. Illustratively, the single cell has a volumetric energy density of 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 above values. The single cell has a high volumetric energy density.

[0645] In the embodiments of the present application, the volumetric energy density of the single cell has the meaning known in the art and can be detected using devices and methods known in the art, for example, using a battery charging upper limit voltage of 3.65 V and a battery discharging cut-off voltage of 2.0 V as an example for illustration,

[0646] The single cell is placed at 25°C, charged to 3.65 V at a constant current of 0.33C, then charged at a constant voltage of 0.05C, discharged to 2.0 V at a constant current of 0.33C, and the discharge capacity A0 at this time is recorded, unit: Ah. The length, width, and height of the single cell are measured using a caliper (generally calculated based on the size of the battery shell, excluding the height of the electrode terminal, and excluding the insulating film outside the shell), the volume V0 of the single cell is calculated, unit: L, and the volumetric energy density VED of the single cell is (A0 x discharge platform voltage) / V0, unit: Wh / L.

[0647] The volume energy density of the single battery cell is 290-500 Wh / L, which enables the energy storage unit to store a large amount of electrical energy in a limited space, providing stable and sufficient energy support for the high-power output of the charging module 120. In the process of realizing fast charging, the high-energy-density single battery cell enables the energy storage unit to continuously power the charging module 120, further optimizing the performance of the charging device 100 to enable the charging device 100 to operate stably at high-power output.

[0648] Electricity using device

[0649] The second aspect of the embodiments of the present application provides a power-using device, which comprises the battery device of the embodiments of the present application, such as a single battery cell, a battery module or a battery pack. The single battery cell, the battery module or the battery pack can be used as a power source of the power-using device, or as an energy storage unit of the power-using device. The power-using device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The vehicle can be a fuel car, a gas car or a new energy car, the new energy car can be a pure electric car, a hybrid electric car or an extended-range car, etc., the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc., 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 plane toy, etc., the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, such as 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, etc. The embodiments of the present application do not specially limit the above-mentioned power-using devices.

[0650] The power-using device can select a single battery cell, a battery module or a battery pack according to its use requirements.

[0651] Figure 27 is a schematic diagram of a power-using device 1 as an example. The power-using device 1 is a pure electric vehicle, a hybrid electric vehicle or a plug-in hybrid electric vehicle, etc. In order to meet the requirements of high power and high energy density of the power-using device 1, a battery pack or a battery module can be used.

[0652] The power-using device 1 is internally provided with a battery pack 2, which can be arranged at the bottom, head or tail of the power-using device 1. The battery pack 2 can be used for power supply of the power-using device 1, for example, the battery pack 2 can be used as an operating power source of the power-using device 1, and also can be used as a driving power source of the power-using device 1, instead of or partially instead of fuel or natural gas to provide driving power for the power-using device 1.

[0653] The electric device 1 can further include a controller 3 and a motor 4, the controller 3 being configured to control the battery pack 2 to supply power to the motor 4, for example, for power requirements of the electric device 1 for starting, navigation, and operation during travel.

[0654] As another example, the electric device can be a mobile phone, a tablet computer, a notebook computer, or the like. The electric device generally requires thinness and can employ a single battery cell as a power source.

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

[0656] charging from 10% SOC to 15% SOC at 5.0C constant current,

[0657] charging from 15% SOC to 20% SOC at 5.0C constant current,

[0658] charging from 20% SOC to 25% SOC at 5.0C constant current,

[0659] charging from 25% SOC to 30% SOC at 5.0C constant current,

[0660] charging from 30% SOC to 35% SOC at 5.0C constant current,

[0661] charging from 35% SOC to 40% SOC at 5.0C constant current,

[0662] charging from 40% SOC to 45% SOC at 4.6C constant current,

[0663] charging from 45% SOC to 50% SOC at 4.3C constant current,

[0664] charging from 50% SOC to 55% SOC at 4.0C constant current,

[0665] charging from 55% SOC to 60% SOC at 3.7C constant current,

[0666] charging from 60% SOC to 65% SOC at 3.4C constant current,

[0667] charging from 65% SOC to 70% SOC at 3.1C constant current,

[0668] charging from 70% SOC to 75% SOC at 2.9C constant current,

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

[0670] In some embodiments, the charging time of the power-consuming device from 10% state of charge to 80% state of charge is less than or equal to 10.5 minutes, optionally 5 minutes to 10.5 minutes, and the temperature of the external environment of the battery pack 2 at 10% state of charge is room temperature, for example, 30°C. Illustratively, 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 defined by any two of the above values.

[0671] Embodiments

[0672] The following examples more particularly exemplify the application as contemplated by the instant disclosure. These examples are intended merely to be illustrative and the practice thereof will be apparent to those skilled in the art from consideration of the disclosure herein. Unless otherwise indicated, all parts, percentages and ratios reported herein are on a mass basis and all reagents used in the examples are commercially available or are prepared in accordance with known procedures and used without further purification, and the equipment used in the examples is commercially available.

[0673] Example 1

[0674] 1. Preparation of the positive electrode tab

[0675] The positive electrode tab includes a positive electrode current collector, a positive electrode conductive layer on the positive electrode current collector, and a positive electrode film layer.

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

[0677] The positive electrode film layer includes a film layer formed by uniformly coating a positive electrode slurry (the solvent is N-methyl pyrrolidone (NMP)) on the surface of the positive electrode conductive layer, and then 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, and the coating layer is coated on the surface of the lithium iron phosphate. The coating layer includes lithium titanium iron phosphate, Li2FeTi(PO4)3, and amorphous carbon. The Dv50 of the positive electrode active material is 1.6 μm, and the Dv10 is 0.64 μm.

[0679] The single-side coating weight of the positive electrode film layer is 300 mg / 1540.25 mm 2 .

[0680] 2. Preparation of the negative electrode tab

[0681] The negative electrode tab comprises a negative electrode current collector, a negative electrode conductive layer on the negative electrode current collector, and a negative electrode film layer.

[0682] The negative electrode conductive layer on the negative electrode current collector is a film layer formed by uniformly mixing a negative electrode conductive agent, a negative electrode binder, a thickening agent, and a solvent, and then coating the mixture on the surface of the negative electrode current collector and drying, wherein the thickness of the negative electrode conductive layer is 1 μm, the mass content of the negative electrode conductive agent in the negative electrode conductive layer is 35%, the mass content of the negative electrode binder in the negative electrode conductive layer is 60%, and the mass content of the thickening agent in the negative electrode conductive layer is 5%.

[0683] The negative electrode film layer is a film layer for...

Claims

1. A charge storage system characterized by, The charging device comprises a plurality of charging devices, and the plurality of charging devices share a direct current bus or an alternating current bus. The energy storage module comprises a plurality of energy storage units, each of which has a first positive power supply end and a first negative power supply end, and the plurality of energy storage units are connected to the second positive power supply end and the second negative power supply end of the energy storage module through the first positive power supply end and the first negative power supply end, and the energy storage module is configured to provide first direct current; The input module comprises an input interface, and the input module is adapted to provide charging energy for each of the energy storage units; The charging module is connected to the second positive power supply end and the second negative power supply end of the energy storage module, and the charging module is configured to adapt to the charging output based on the first direct current, the maximum charging output power of the charging module is greater than or equal to 350 kW, and / or the rated charging output power of the charging module is greater than or equal to 290 kW, the ratio between the maximum charging output power of the charging module and the maximum output power of the input module is greater than 1 and less than or equal to 15, and / or the ratio between the rated charging output power of the charging module and the rated output power of the input module is greater than 1 and less than or equal to 15, when the number of energy storage units is a plurality, the energy storage units and the charging module are configured to charge the electrical equipment at different output powers; The plurality of energy storage units are connected in series and / or parallel through the first positive power supply end and the first negative power supply end between the second positive power supply end and the second negative power supply end of the energy storage module to provide the first direct current; Each of the energy storage units comprises a battery subunit, and each of the energy storage units is configured to provide second direct current based on the electrical energy of the battery subunit; At least part of the plurality of energy storage units further comprises a first power conversion subunit, the number of the first power conversion subunits is a plurality, the first power conversion subunits are respectively connected to the first positive power supply end and the first negative power supply end of the corresponding battery subunit and energy storage unit, the first power conversion subunit is a bidirectional DCDC subunit, at least one of the bidirectional DCDC subunits is connected to the direct current bus, and the first power conversion subunit is configured to convert the electrical energy of the battery subunit into the second direct current; A first transformer has a primary winding connected to an alternating current grid and is configured to convert second alternating current provided by the alternating current grid into first alternating current; A first AC / DC conversion module is connected to the secondary winding of the first transformer and the direct current bus, and is configured to convert the first alternating current into third direct current; The second positive power supply end and the second negative power supply end of the energy storage module of the plurality of charging devices are connected to the direct current bus.

2. The refill system of claim 1, wherein, The ratio between the rated output power of the input module and the rated energy of the battery subunit is greater than or equal to 1 / n1, wherein n1 is in the range of 1-4.

3. The fill storage system of claim 1, wherein, A ratio between a rated energy of the battery subunit and a rated charging output power of the charging module is greater than or equal to 1 / (n2*n3), where n2 is in a range from 94% to 99% and n3 is in a range from 4 to 6.

4. The refill system of claim 1, wherein, A ratio between the rated energy of the battery subunit and a rated power of the battery subunit is less than or equal to 1 / 3, and / or a volumetric energy density of the battery subunit is greater than or equal to 380 Wh / L.

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

6. The fill storage system of claim 5, wherein, The electrolyte further includes an organic solvent, and the organic solvent includes a carbonate-based solvent.

7. The fill storage system of claim 5, wherein, The electrolyte salt further includes a fluorine-containing sulfonimide salt, and a concentration of the fluorine-containing sulfonimide salt is in a range from 0.2 mol / L to 0.5 mol / L.

8. The fill storage system of claim 5, wherein, The electrolyte further includes an organic solvent, and the organic solvent includes a chain carboxylate-based solvent, and a mass content A of the chain carboxylate-based solvent based on a total mass of the solvent satisfies 5%≤A≤75%, wherein the chain carboxylate-based solvent includes a compound having 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 fill storage system of claim 8, wherein, 40%≤A≤75%。 10. The charging and storage system according to any of claims 1-4, characterized in that, The battery subunit includes a single cell, and the single cell includes a negative electrode sheet, and the negative electrode sheet 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, and 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.

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

12. The refill system of any one of claims 1-4, wherein, The battery subunit includes a single cell, and the single cell includes a negative electrode sheet, and the negative electrode sheet 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. The compaction density of the negative electrode film layer is 1.15 g / cm 3 -1.36 g / cm 3 , and / or the single-side coating weight of the negative electrode film layer is 0.09 g / 15 40.25 mm 2 -0.17 g / 15 40.25 mm 2 .

13. The refill system of any one of claims 1-4, wherein, The battery subunit includes a single cell, and the single cell includes a positive electrode sheet, and the positive electrode sheet 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 monomer cell has a compaction density of the positive electrode film layer of 2.5 g / cm 3 -2.8 g / cm 3 , and / or a single-side coating weight of the positive electrode film layer of 0.2 g / 15 40.25 mm 2 -0.37 g / 15 40.25 mm 2 .

14. The refill system of any one of claims 1-4, wherein, The battery subunit includes a single cell, and the single cell includes a positive electrode sheet, and the positive electrode sheet 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 a thickness of the positive electrode current collector is in a range from 10 μm to 15 μm.

15. The refill system of any one of claims 1-4, wherein, The battery subunit comprises a single cell, and the single cell comprises a separator film, and the separator film comprises a base film with a porous structure, and the porosity of the base film is 20% to 70%.

16. The refill system of any one of claims 1-4, wherein, The battery subunit comprises a positive electrode sheet, and the positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer arranged on at least one side of the positive electrode current collector, and the positive electrode film layer comprises a positive electrode active material, and the positive electrode active material comprises a lithium-containing phosphate; The lithium-containing phosphate comprises phosphate particles and a coating layer, and the coating layer is coated on at least part of the surface of the phosphate particles, and the coating layer comprises one or more elements of C, Fe, Ti, Zr, Hf, Ge and Sn.

17. The fill storage system of claim 16, wherein, The cladding layer includes a fast ion conductor, wherein the fast ion conductor includes a compound of the general formula Li 3-d Fe 2-d M 2d a compound of the general formula (PO4)3, M2 includes at least one element of Ti, Zr, Hf, Ge, and Sn, and 0≤d≤1.

18. The refill system of any one of claims 1-4, wherein, The battery subunit comprises a positive electrode sheet, and the positive electrode sheet comprises a positive electrode current collector, a positive electrode conductive layer and a positive electrode film layer, and the positive electrode film layer is arranged on at least one side of the positive electrode current collector, and 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 to 2 μm; and / or The battery subunit comprises a negative electrode sheet, and the negative electrode sheet comprises a negative electrode current collector, a negative electrode conductive layer and a negative electrode film layer, and 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, and the thickness of the negative electrode conductive layer is in the range of 0.5 μm to 2 μm.

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

20. The charging and storage system 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% to 40% based on the total mass of the negative electrode conductive layer; and / or The negative electrode conductive layer comprises a negative electrode binder, and the mass content of the negative electrode binder is in the range of 60% to 80% based on the total mass of the negative electrode conductive layer.

21. The refill system of claim 1, wherein, At least part of the one or more energy storage units further comprises a first switch subunit, and the first switch subunit is connected with the first positive power supply end and the first negative power supply end of the corresponding battery subunit and energy storage unit respectively, and is configured to connect the corresponding battery subunit with the first positive power supply end and the first negative power supply end of the energy storage unit in a conductive state to provide the second direct current. In the case that the energy storage unit does not comprise the first switch subunit, the battery subunit is directly connected with the first positive power supply end and the first negative power supply end of the corresponding energy storage unit to provide the second direct current.

22. The fill storage system of claim 21, wherein, At least part of the one or more energy storage units further comprises a first power conversion subunit and a first switch subunit, the first power conversion subunit and the first switch subunit are connected in series between the first positive power terminal and the first negative power terminal of the corresponding battery subunit and the energy storage unit, 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. When the energy storage unit does not comprise the first power conversion subunit and the first switch subunit, the battery subunit is directly connected to the first positive power terminal and the first negative power terminal of the corresponding energy storage unit to provide the second direct current.

23. The refill system of any one of claims 1, 21 or 22, wherein, The energy storage module further comprises a selection unit connected to the one or more energy storage units, configured to select at least one energy storage unit from the one or more energy storage units to be connected to the second positive power terminal and the second negative power terminal of the energy storage module to provide the first direct current.

24. The fill storage system of claim 23, wherein, The second positive power terminal and the second negative power terminal of the energy storage module each comprises one, the selection unit comprises a plurality of second switch subunits, each of the second switch subunits is connected to one of the energy storage units, each of the second switch subunits is connected in series between the first positive power terminal of the corresponding energy storage unit and the second positive power terminal of the energy storage module, the first negative power terminal of the one or more energy storage units is connected to the second negative power terminal of the energy storage module respectively, and the second switch subunit is configured to connect the first positive power terminal of the corresponding energy storage unit to the second positive power terminal of the energy storage module when turned on.

25. The fill storage system of claim 24, wherein, The charging module comprises a fifth power conversion subunit and a charging gun, the positive input terminal and the negative input terminal of the fifth power conversion subunit are connected to the second positive power terminal and the second negative power terminal of the energy storage module respectively, the positive output terminal and the negative output terminal of the fifth power conversion subunit are connected to the positive input terminal and the negative input terminal of the charging gun respectively, and the fifth power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

26. The fill storage system of claim 24, wherein, The charging module comprises 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 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, the negative input terminal of the charging gun is connected to the second negative power terminal of the energy storage module, and the sixth power conversion subunit is configured to convert the first direct current into a fourth direct current for charging output through the charging gun.

27. The fill storage system of claim 26, wherein, The second positive power supply end of the energy storage module includes a plurality of, the second negative power supply end of the energy storage module includes one, the selection unit includes a plurality of second switch subunits, each of the second switch subunits is connected with one of the energy storage units and one of the second positive power supply ends, each of the second switch subunits is connected in series between the first positive power supply end of the corresponding energy storage unit and the corresponding second positive power supply end, the first negative power supply end of the one or more energy storage units is connected with the second negative power supply end of the energy storage module respectively, and the second switch subunit is configured to connect the first positive power supply end of the corresponding energy storage unit with the corresponding second positive power supply end in the case of conduction.

28. The fill storage system of claim 27, wherein, The charging module includes a plurality of seventh power conversion subunits and a charging gun, the positive input end and the negative input end of each of the seventh power conversion subunits are connected with one of the second positive power supply ends and the second negative power supply end, the positive output end and the negative output end of each of the seventh power conversion subunits are connected with the positive input end and the negative input end of the charging gun, and the plurality of seventh power conversion subunits are configured to convert the first direct current into fourth direct current for charging output through the charging gun.

29. The fill storage system of claim 27, wherein, The charging module includes a plurality of eighth power conversion subunits and a charging gun, the positive input end of each of the eighth power conversion subunits is connected with one of the second positive power supply ends, the positive output end of each of the eighth power conversion subunits is connected with the positive input end of the charging gun, the negative input end of the charging gun is connected with the second negative power supply end of the energy storage module, and the plurality of eighth power conversion subunits are configured to convert the first direct current into fourth direct current for charging output through the charging gun.

30. The fill storage system of claim 23, wherein, The input module includes a ninth power conversion subunit, the ninth power conversion subunit is connected with the one or more energy storage units and is configured to provide charging energy for each of the energy storage units based on the first alternating current provided by the second external power supply.

31. The fill storage system of claim 23, wherein, The input module includes a plurality of tenth power conversion subunits, each of the tenth power conversion subunits is connected with one of the energy storage units, and the plurality of tenth power conversion subunits are configured to provide charging energy for each of the energy storage units based on the first alternating current provided by the second external power supply.

32. The recharging system of any one of claims 1, 21 or 22, wherein, 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 with the wireless communication module to interact with external equipment through the wireless communication module.

33. A charging station, characterized in that The charging and storage system includes the charging and storage system according to any one of claims 1-32.

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