Charging system and charging method

Abstract

This application discloses a charging system and charging method. The charging system includes a charging device and an electrical device. The charging device includes an energy storage device and is configured to determine the charging demand information of the electrical device in response to a charging event; determine a target charging mode for charging the electrical device based on the charging demand information, wherein the target charging mode corresponds to target charging parameters; the charging device includes an energy storage device; and charge the electrical device based on the target charging parameters corresponding to the target charging mode. Where the target charging mode includes a first charging mode, the target charging parameters corresponding to the first charging mode include first charging parameters, and the charging power indicated by the first charging parameters is greater than 300 kilowatts.

Description

[0001] Cross-references to related applications

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

[0003] A PCT international patent application filed on May 15, 2024, with application number PCT / CN2024 / 093513 and title "Charging device, charging pile and charging and storage system";

[0004] A PCT international patent application filed on June 28, 2024, with application number PCT / CN2024 / 102652 and title "Battery cell, battery and electrical device";

[0005] The PCT international patent application filed on May 15, 2024, with application number PCT / CN2024093517 and title "Charging method, system, apparatus, storage medium and program product". Technical Field

[0006] This application relates to the field of charging technology, specifically to a charging system and charging method. Background Technology

[0007] With the rapid increase in electrical devices, problems such as slow charging and poor user experience urgently need to be solved. In order to meet the charging needs of electrical devices in different scenarios, various charging modes have emerged. However, there is currently no good method to determine the appropriate charging mode for electrical devices. Summary of the Invention

[0008] In view of this, embodiments of this application provide at least one charging system and charging method.

[0009] In a first aspect, this application provides a charging system, including a charging device and an electrical device, wherein the charging device includes an energy storage device;

[0010] A charging device is configured to, in response to a charging event, determine the charging demand information of an electrical device; based on the charging demand information, determine a target charging mode for the charging device to charge the electrical device, wherein the target charging mode corresponds to target charging parameters; the charging device includes an energy storage device and a ninth determining module, the ninth determining module being configured to, based on a state of charge value and a remaining energy state value, determine whether the energy storage device can charge the electrical device with the target charging parameters; and charge the electrical device based on the target charging parameters corresponding to the target charging mode;

[0011] Wherein, when the target charging mode includes the first charging mode, the target charging parameters corresponding to the first charging mode include the first charging parameters, and the charging power indicated by the first charging parameters is greater than 300 kilowatts.

[0012] In this embodiment, based on the charging demand information of the electrical equipment, the target charging mode for the charging device to charge the electrical equipment is determined. Then, based on the target charging parameters corresponding to the target charging mode, the electrical equipment is charged. In this way, when there are multiple charging modes, the most suitable charging mode can be determined to charge the electrical equipment based on the charging demand information of the electrical equipment.

[0013] In some embodiments, the charging device includes a charging control device, which includes:

[0014] The first determining module is configured to determine the charging demand information of the electrical equipment in response to a charging event.

[0015] The second determining module is configured to determine the target charging mode for the charging device to charge the electrical equipment based on the charging demand information.

[0016] The target charging mode corresponds to the target charging parameters; the charging device includes an energy storage device.

[0017] The first charging module is configured to charge the electrical equipment based on the target charging parameters corresponding to the target charging mode;

[0018] Wherein, when the target charging mode includes the first charging mode, the target charging parameters corresponding to the first charging mode include the first charging parameters, and the charging power indicated by the first charging parameters is greater than 300 kilowatts.

[0019] In some embodiments, the energy storage device and / or charging device satisfy one or more of the following conditions:

[0020] The ratio between the rated energy of the energy storage device and the maximum discharge power of the energy storage device shall not exceed 1:3;

[0021] The energy density of the energy storage device is greater than or equal to 380 Wh / L;

[0022] The ratio between the rated energy of the energy storage device and the maximum charging power of the charging device is less than 1:4.

[0023] In this embodiment of the application, based on the current state of charge and / or remaining energy state of the energy storage device, it can be determined that the energy storage device can support the following operating mode: the energy storage device provides the electrical equipment with the full power indicated by the charging parameters in the charging mode, so that the energy storage device can be controlled to charge the electrical equipment independently.

[0024] In some embodiments, the energy storage device includes one or more energy storage units, each energy storage unit having a first positive power supply terminal and a first negative power supply terminal, and the one or more energy storage units are connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage device through the first positive power supply terminal and the first negative power supply terminal, and the energy storage device is configured to provide a first direct current.

[0025] The charging device also includes a charging module and an input module. The charging module is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage device. The charging module is configured to output charging power based on a first DC power supply. The input module is adapted to provide charging energy to each energy storage unit. 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.

[0026] In the technical solution of this application embodiment, the input module can be adapted to provide charging energy to the energy storage unit. In different power environments, whether it is an old urban area with relatively tight power supply or a remote area that is sensitive to the cost of infrastructure construction, the charging device can realize fast charging function by means of the cooperation of the input module and the energy storage module without relying on external complex power supply upgrades, thereby enhancing the applicability and flexibility of the charging device in various scenarios.

[0027] Without the need for additional transformers or transformer capacity expansion, by configuring an energy storage unit inside the charging device, not only can fast charging, such as fast charging / supercharging, be achieved, but the costs associated with adding or expanding transformers can also be reduced.

[0028] In some embodiments, 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.

[0029] This reduces problems such as current surges and overheating caused by instantaneous high power input to the charging module. The input module charges the energy storage module with low power, and the energy storage module then outputs controllable high power to the charging module. The energy storage module can flexibly adjust its output power according to its stored power and the power demand of the device, enabling the charging device to rationally distribute power, reduce unnecessary energy consumption, improve the cost-effectiveness of the charging device, and ensure stable operation of the charging device when there is low power input and high power output.

[0030] In some embodiments, each energy storage unit includes a battery sub-unit, and the ratio between the rated output power of the input module and the rated energy of the battery sub-unit is greater than or equal to 1 / n1, wherein the value of n1 ranges from 1 to 4.

[0031] Therefore, when there is low power input and high power output, the battery sub-units can charge the electrical equipment at different charging rates. The charging rate can be adjusted according to the charging needs of the electrical equipment during the charging process or at different charging time periods. This allows the charging device to make reasonable use of its stored electrical energy to charge the electrical equipment, thus improving the cost-effectiveness of the entire charging device and enhancing its operational stability. During different charging processes, the charging device acts as a "buffer" between the power grid and the electrical equipment, reducing the impact of high power output on the power grid.

[0032] 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), wherein the value of n2 ranges from 94% to 99%, and the value of n3 ranges from 4 to 6.

[0033] Therefore, while ensuring charging performance, the reliability of the charging device is also taken into account. When the rated energy of the battery sub-unit matches the rated charging output power of the charging module, the battery sub-unit can stably provide energy to the charging module during the charging process, reducing the possibility of unstable or interrupted charging power due to insufficient energy supply. Taking n2 as 94% and n3 as 6 as an example, the larger denominator requires the battery sub-unit to have a relatively high rated energy to match the power of the charging module. This allows the charging device to work continuously and stably during long-term, high-power charging, reducing the probability of failure, lowering maintenance costs, and improving the cost-effectiveness from the perspective of the charging device's lifespan.

[0034] In some embodiments, each energy storage unit includes a battery sub-cell, wherein the ratio between the rated energy and the rated power of the battery sub-cell is less than or equal to 1 / 3, and / or the volumetric energy density of the battery sub-cell is greater than or equal to 380 Wh / L.

[0035] When the charging device outputs high power (the maximum charging output power of the charging module is above 350kW), the rated energy of the battery sub-unit is matched with the rated power. This reduces grid fluctuations caused by insufficient rated energy of the battery sub-unit due to high power output, which requires grid power supply. This helps improve the reliability and stability of the charging device. Furthermore, when the charging device is outputting high power, it can operate continuously and stably, reducing the probability of failure and lowering maintenance costs. From the perspective of the charging device's lifespan, this improves the cost-effectiveness.

[0036] 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 lithium hexafluorophosphate is in the range of 0.5 mol / L-1.0 mol / L.

[0037] By setting the electrolyte to include lithium hexafluorophosphate of the above concentration, the battery sub-cell has a high ionic conductivity, thereby improving the charging rate of the charging device. It also gives the battery sub-cell high interface stability and high thermal stability. Lithium hexafluorophosphate has a small impact on the severity of thermal runaway, so that the battery sub-cell has a suitable degree of thermal runaway severity and a low risk of thermal diffusion, which makes the charging device highly reliable when the power output is above 350kW.

[0038] In some embodiments, the electrolyte further includes an organic solvent, including carbonate solvents.

[0039] Adding carbonate solvents to the electrolyte can improve various performance characteristics of battery sub-cells, such as charge / discharge efficiency, cycle performance, low-temperature performance, and high voltage stability.

[0040] In some embodiments, the electrolyte salt further includes a fluorosulfonamide salt, the concentration of which is in the range of 0.2 mol / L to 0.5 mol / L.

[0041] Because fluorosulfonyl imide salts have low viscosity and high ionic conductivity, electrolytes containing the above-mentioned concentrations of fluorosulfonyl imide salts are beneficial to improving the charging rate of battery sub-cells, thereby improving the charging rate of the charging device.

[0042] In some embodiments, the electrolyte further includes an organic solvent, including chain carboxylic acid ester solvents, wherein the mass content A of the chain carboxylic acid ester solvent, based on the total mass of the solvent, satisfies the following condition: 5% ≤ A ≤ 75%.

[0043] Among them, chain carboxylic acid ester solvents include compounds with the following structures:

[0044]

[0045] Wherein, R1 includes at least one of hydrogen atom, C1-C5 alkyl or C1-C5 haloalkyl, and R2 includes C1-C5 alkyl and / or C1-C5 haloalkyl.

[0046] In this technical solution, the solvent includes carboxylic acid ester solvents, so that the electrolyte can have higher ionic conductivity and relatively low viscosity, which is beneficial to further improve the fast charging performance of the charging device, such as fast charging performance and / or supercharging performance.

[0047] In some embodiments, 40% ≤ A ≤ 75%.

[0048] Setting A to greater than or equal to 40% and less than or equal to 75% can better achieve the purpose of fast charging of the charging device.

[0049] 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 a negative electrode sheet, the negative electrode sheet includes a negative current collector and a negative electrode film layer disposed on at least one side of the negative current collector, the negative electrode film layer includes a negative electrode active material, the negative electrode active material includes a carbon-based material, and the carbon-based material includes at least one of natural graphite and artificial graphite.

[0050] Carbon-based materials employing at least one of natural graphite and artificial graphite as the negative electrode active material possess both excellent conductivity and high theoretical specific capacity. Natural graphite exhibits high crystallinity and a regular layered structure, which facilitates the rapid insertion and extraction of lithium ions, thereby improving battery charge and discharge efficiency. Artificial graphite, through precise control of the production process, can enhance battery cycle stability and extend battery life by precisely adjusting its microstructure and performance.

[0051] In some embodiments, the volume average particle size Dv50 of the negative electrode film is in the range of 8.2 μm to 13.5 μm.

[0052] Therefore, this particle size range can balance specific surface area and compaction density. Smaller particle size can provide a larger specific surface area, increase the reaction sites of lithium ions, and improve the charge and discharge rate performance of the battery; while an appropriate particle size can ensure a higher compaction density, reduce the gaps between active materials, and improve the energy density of the battery, thus achieving a good balance between rate performance and energy density.

[0053] In some embodiments, the negative electrode film layer includes a first negative electrode active material layer and a second negative electrode active material layer stacked together. The first negative electrode active material layer is located on the side close to the negative electrode current collector. The volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer is 9.5 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.

[0054] When the volume average particle size Dv50 of the negative electrode active material in both the first and second negative electrode active material layers is within the aforementioned range, it can shorten the solid-phase transport path of lithium ions, improving fast charging performance. Furthermore, the materials are less prone to agglomeration during preparation, thus enhancing material stability. The combination of the negative electrode active materials in the second and first negative electrode active material layers within the aforementioned volume average particle size range facilitates the creation of a gradient porosity difference between the two layers, reducing lithium ion transport tortuosity and improving the fast charging performance of the battery cell.

[0055] 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 a negative electrode sheet, the negative electrode sheet includes a negative current collector and a negative electrode film layer located at least on one side of the negative current collector, the negative electrode film layer includes a negative electrode active material layer.

[0056] When a single battery cell is 100% charged, the compaction density of the negative electrode film is 1.15 g / cm³. 3 -1.36g / cm 3 And / or, the single-sided coating weight of the negative electrode film is 0.09 g / 1540.25 mm. 2 -0.17g / 1540.25mm 2 .

[0057] When the compaction density of the negative electrode film is within the above range, it is beneficial to improve the energy density of the battery cell. Furthermore, because the negative electrode active material in the negative electrode film is densely packed, the contact resistance between particles is low, which can further reduce the resistance of the electrode sheet, thereby reducing heat generation. When the single-sided coating weight of the negative electrode film is within the above range, the heat generation per unit area of ​​the negative electrode sheet will not be excessive, while still maintaining an improved energy density for the battery cell.

[0058] 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 a positive electrode sheet, the positive electrode sheet includes a positive current collector and a positive electrode film layer located at least on one side of the positive current collector, and the positive electrode film layer includes a positive active material layer.

[0059] When a single battery cell is 100% charged, the compaction density of the positive electrode film is 2.5 g / cm³. 3 -2.8g / cm 3 .

[0060] When the compaction density of the positive electrode film is within the above range, it is beneficial to improve the energy density of the battery cell. Furthermore, since the positive electrode active material in the positive electrode film is packed more tightly, the contact resistance between particles is smaller, which can further reduce the resistance of the electrode sheet, thereby reducing heat generation.

[0061] In some embodiments, the single-sided coating weight of the positive electrode film is 0.2 g / 1540.25 mm. 2 -0.37g / 1540.25mm 2 .

[0062] 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 the energy density of the battery cell can be improved at the same time.

[0063] 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 a positive electrode sheet, the positive electrode sheet includes a positive current collector and a positive electrode film layer located at least on one side of the positive current collector, and the thickness of the positive current collector is 10μm-15μm.

[0064] When the thickness of the positive electrode current collector is within the above range, the current-carrying capacity of the positive electrode current collector is excellent, and it can enable the battery cell to have a high energy density.

[0065] 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 a separator, the separator includes a porous base film, and the porosity of the base film is 20% to 70%.

[0066] When the porosity of the base film is within the above range, it can enhance the migration ability of lithium ions in the separator, reduce the internal resistance of the battery cell, and thus reduce heat generation.

[0067] In some embodiments, each energy storage unit includes a battery sub-unit, the battery sub-unit includes a positive electrode sheet, the positive electrode sheet includes a positive current collector and a positive electrode film layer disposed on at least one side of the positive current collector, the positive electrode film layer includes a positive electrode active material, and the positive electrode active material includes a lithium phosphate.

[0068] The lithium-containing phosphate includes phosphate particles and a coating layer. The coating layer covers at least a portion of the surface of the phosphate particles and includes one or more elements selected from C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0069] Under this technical solution, the positive electrode coating layer has excellent ion and electron conduction capabilities, which can improve the ionic conductivity and electronic conductivity of the positive electrode active material, thereby effectively improving the charging rate of the battery sub-cell, enhancing the fast charging performance of the charging device, and improving the fast charging performance of the battery device.

[0070] In some embodiments, the cladding layer includes a fast ion conductor, wherein the fast ion conductor comprises a material of the general formula Li. 3-d Fe 2- d M2d (PO4)3 compounds, M2 including at least one element selected from Ti, Zr, Hf, Ge and Sn, 0≤d≤1.

[0071] Because fast ion conductors have high ionic conductivity, which is beneficial for the diffusion and transport of lithium ions, the charging rate of battery sub-cells can be further improved, thus enhancing the fast charging performance of the charging device and improving the fast charging performance of the battery device.

[0072] In some embodiments, each energy storage unit includes a battery sub-unit, the battery sub-unit includes a positive electrode sheet, the positive electrode sheet includes a positive current collector, a positive conductive layer and a positive film layer, the positive film layer is disposed on at least one side of the positive current collector, the positive conductive layer is located between the positive current collector and the positive film layer, and the thickness of the positive conductive layer is in the range of 0.5μm-2μm.

[0073] This shortens the diffusion path of lithium ions, thereby improving the rate performance of battery sub-cells and enhancing the fast charging performance of battery devices.

[0074] In some embodiments, the positive electrode conductive layer includes a positive electrode conductive agent, and the mass content of the positive electrode conductive agent is in the range of 30%-50% based on the total mass of the positive electrode conductive layer.

[0075] This technical solution sets the mass content of the positive electrode conductive agent in the range of 30%-50%, which can improve the electron transport efficiency in the positive electrode sheet, thereby improving the rate performance of the battery sub-cell.

[0076] In some embodiments, the positive electrode conductive layer includes a positive electrode binder, and the mass content of the positive electrode binder is in the range of 50%-70% based on the total mass of the positive electrode conductive layer.

[0077] This technical solution sets the mass content of the positive electrode binder in the range of 50%-70%, which can reduce the possibility of cracking or peeling of the positive electrode sheet during cycling, thereby improving the cycle life of the battery sub-cell.

[0078] In some embodiments, each energy storage unit includes a battery sub-unit, the battery sub-unit includes a negative electrode sheet, the negative electrode sheet includes a negative current collector, a negative conductive layer and a negative electrode film layer, the negative electrode film layer is disposed on at least one side of the negative current collector, the negative conductive layer is located between the negative current collector and the negative electrode film layer, and the thickness of the negative conductive layer is in the range of 0.5μm-2μm.

[0079] This shortens the diffusion path of lithium ions, thereby improving the rate performance of battery sub-cells and enhancing the fast charging performance of battery devices.

[0080] In some embodiments, the negative electrode conductive layer includes a negative electrode conductive agent, and the mass content of the negative electrode conductive agent is in the range of 20%-40% based on the total mass of the negative electrode conductive layer.

[0081] This technical solution sets the mass content of the negative electrode conductive agent in the range of 20%-40%, which can improve the electron transport efficiency in the negative electrode sheet, thereby improving the rate performance of the battery sub-cell and enhancing the fast charging performance of the battery device.

[0082] In some embodiments, the negative electrode conductive layer includes a negative electrode adhesive, and the mass content of the negative electrode adhesive is in the range of 60%-80% based on the total mass of the negative electrode conductive layer.

[0083] This technical solution sets the mass content of the negative electrode binder in the range of 60%-80%, which can reduce the possibility of cracking or peeling of the negative electrode sheet during cycling, thereby improving the cycle life of the battery sub-cell and thus improving the cycle life of the battery device.

[0084] In some embodiments, one or more energy storage units are connected in series and / or in parallel between the second positive and second negative power supply terminals of the energy storage module of the energy storage device via a first positive power supply terminal and a first negative power supply terminal to provide a first direct current. This configuration enables the charging and storage system to achieve low-power input and high-power output, thereby improving the adaptability of the charging and storage system.

[0085] In some embodiments, each energy storage unit includes a battery sub-unit, and each energy storage unit is configured to provide a second direct current based on the electrical energy of the battery sub-unit.

[0086] In some embodiments, at least a portion of the energy storage units in one or more energy storage units further includes a first power conversion subunit. The first power conversion subunit is connected to a first positive power supply terminal and a first negative power supply terminal of the corresponding battery subunit and energy storage unit, respectively, and is configured to convert the electrical energy of the battery subunit into a second direct current. Where the energy storage unit does not include the first power conversion subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current. This improves charging flexibility.

[0087] In some embodiments, at least some of the energy storage units in one or more energy storage units further include a first switching subunit. The first switching subunit is connected to a first positive power supply terminal and a first negative power supply terminal of a corresponding battery subunit and the energy storage unit, respectively, and is configured to connect the corresponding battery subunit to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit when the circuit is turned on, so as to provide a second DC power. Wherein, if the energy storage unit does not include the first switching subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second DC power. This provides protection for the energy storage unit.

[0088] In some embodiments, at least a portion of one or more energy storage units further includes a first power conversion subunit and a first switching subunit, which are connected in series between a first positive power supply terminal and a first negative power supply terminal of the corresponding battery subunit and energy storage unit. The first power conversion subunit is configured to convert electrical energy from the battery subunit into a second direct current when the corresponding first switching subunit is turned on. Alternatively, if the energy storage unit does not include the first power conversion subunit and the first switching subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current. This improves charging flexibility and protects the energy storage unit.

[0089] In some embodiments, the input module includes an input interface connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage module, configured to provide charging energy to each energy storage unit based on a third DC power supply provided by a first external power source; alternatively, the input module includes a second power conversion subunit connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage module, configured to provide charging energy to each energy storage unit based on a first AC power supply provided by a second external power source. This allows either AC or DC input to charge the energy storage unit.

[0090] In some embodiments, the charging module includes a third power conversion subunit and a charging gun. The positive and negative input terminals of the third power conversion subunit are connected to the second positive and second negative power supply terminals of the energy storage module, respectively. The positive and negative output terminals of the third power conversion subunit are connected to the positive and negative input terminals of the charging gun, respectively. The third power conversion subunit is configured to convert a first DC power into a fourth DC power for charging output through the charging gun. Thus, the charging gun does not share a common negative terminal.

[0091] In some embodiments, the charging module includes a fourth power conversion subunit and a charging gun. The positive input terminal of the fourth power conversion subunit is connected to the second positive power supply terminal of the energy storage module, the positive output terminal of the fourth power conversion subunit is connected to the positive input terminal of the charging gun, and the negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The fourth power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output through the charging gun. This shared negative charge in the charging gun reduces costs.

[0092] In some embodiments, the energy storage module further includes a selection unit connected to one or more energy storage units and configured to select at least one energy storage unit from the one or more energy storage units and connect it to a second positive power supply terminal and a second negative power supply terminal of the energy storage module to provide a first direct current. This improves charging flexibility.

[0093] In some embodiments, the energy storage module includes one second positive power supply terminal and one second negative power supply terminal. The selection unit includes multiple second switch sub-units, each of which is connected to 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 terminals of one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module. The second switch sub-unit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the second positive power supply terminal of the energy storage module when it is turned on.

[0094] In some embodiments, the charging module includes a fifth power conversion subunit and a charging gun. The positive and negative input terminals of the fifth power conversion subunit are connected to the second positive and second negative power supply terminals of the energy storage module, respectively. The positive and negative output terminals of the fifth power conversion subunit are connected to the positive and negative input terminals of the charging gun, respectively. The fifth power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output through the charging gun. Thus, the charging gun does not share a common negative terminal.

[0095] In some embodiments, the charging module includes a sixth power conversion subunit and a charging gun. The positive input terminal of the sixth power conversion subunit is connected to the second positive power supply terminal of the energy storage module, the positive output terminal of the sixth power conversion subunit is connected to the positive input terminal of the charging gun, and the negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The sixth power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output through the charging gun. This shared negative connection of the charging gun reduces costs.

[0096] In some embodiments, the energy storage module includes multiple second positive power terminals and one second negative power terminal. The selection unit includes multiple second switch sub-units. Each second switch sub-unit is connected to an energy storage unit and a second positive power terminal. Each second switch sub-unit is connected in series between the first positive power terminal and the corresponding second positive power terminal of the energy storage unit. The first negative power terminals of one or more energy storage units are respectively connected to the second negative power terminal of the energy storage module. The second switch sub-unit is configured to connect the first positive power terminal of the corresponding energy storage unit to the corresponding second positive power terminal when the module is turned on.

[0097] In some embodiments, the charging module includes a plurality of seventh power conversion subunits and a charging gun. The positive and negative input terminals of each seventh power conversion subunit 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 subunit are connected to the positive and negative input terminals of the charging gun, respectively. The plurality of seventh power conversion subunits are configured to convert a first DC power supply into a fourth DC power supply for charging output via the charging gun. Thus, the charging gun does not share a common negative terminal.

[0098] In some embodiments, the charging module includes a plurality of eighth power conversion sub-units and a charging gun. The positive input terminal of each eighth power conversion sub-unit is connected to a second positive power supply terminal, and the positive output terminal of each eighth power conversion sub-unit is connected to the positive input terminal of the charging gun. The negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The plurality of eighth power conversion sub-units are configured to convert a first DC power supply into a fourth DC power supply for charging output through the charging gun. In this way, the charging gun shares a common negative charge, which can reduce costs.

[0099] In some embodiments, the input module includes a ninth power conversion subunit, which is connected to one or more energy storage units and configured to provide charging energy to each energy storage unit based on a first AC power supplied by a second external power source. Thus, charging of the energy storage units is achieved through a single power conversion subunit.

[0100] In some embodiments, the input module includes a plurality of tenth power conversion sub-units, each of which is connected to an energy storage unit. The plurality of tenth power conversion sub-units are configured to provide charging energy to each energy storage unit based on a first AC power supplied by a second external power source. Thus, charging of the energy storage unit is achieved through the plurality of power conversion sub-units.

[0101] In some embodiments, the charging device includes multiple devices, and the multiple charging devices share a single DC bus or AC bus.

[0102] Specifically, having multiple charging devices share a single DC or AC bus can reduce the number of buses, thereby reducing the space occupied by the entire structure and improving the space utilization of the charging devices.

[0103] In some embodiments, where multiple charging devices share a single DC bus and the input module of the charging device includes an input interface, the system further includes:

[0104] The first transformer, whose primary winding is connected to the AC power grid, is configured to convert the second AC power supplied by the AC power grid into the first AC power.

[0105] The first AC-DC conversion module is connected to the secondary winding and the DC bus of the first transformer, respectively, and is configured to convert the first AC power into the third DC power.

[0106] In this configuration, the second positive power supply terminal and the second negative power supply terminal of the energy storage module in multiple charging devices are both connected to the DC bus. This achieves a common DC bus for multiple charging devices.

[0107] In some embodiments, where multiple charging devices share a single DC bus and the input module of the charging device includes a second power conversion subunit, the system further includes:

[0108] The first transformer has its primary winding connected to the AC power grid, and the second power conversion subunit is connected to the secondary winding and the DC bus of the first transformer respectively. The first transformer is configured to convert the second AC power provided by the AC power grid into the first AC power.

[0109] In this configuration, the second positive power supply terminal and the second negative power supply terminal of the energy storage module in multiple charging devices are both connected to the DC bus. This achieves a common DC bus for multiple charging devices.

[0110] In some embodiments, where multiple charging devices share a single AC bus and the input module of the charging device includes a ninth power conversion subunit or multiple tenth power conversion subunits, the system further includes:

[0111] The second transformer, whose primary winding is connected to the AC power grid and whose secondary winding is connected to the AC bus, is configured to convert the second AC power provided by the AC power grid into the first AC power.

[0112] In this configuration, the ninth power conversion subunit or multiple tenth power conversion subunits of the input modules in several charging devices are all connected to the AC bus. This achieves a common AC bus for multiple charging devices.

[0113] In some embodiments, the charging device further includes a wireless communication module, and at least a portion of the energy storage module, input module, and charging module are connected to the wireless communication module to interact with external devices via the wireless communication module.

[0114] Secondly, this application provides a charging method, the method comprising:

[0115] In response to charging events, determine the charging demand information of electrical equipment;

[0116] Based on charging demand information, the target charging mode for charging devices to charge electrical equipment is determined, wherein the target charging mode corresponds to target charging parameters; the charging device includes an energy storage device.

[0117] The device is charged based on the target charging parameters corresponding to the target charging mode.

[0118] Wherein, when the target charging mode includes the first charging mode, the target charging parameters corresponding to the first charging mode include the first charging parameters, and the charging power indicated by the first charging parameters is greater than 300 kilowatts.

[0119] In this embodiment, based on the charging demand information of the electrical equipment, the target charging mode for the charging device to charge the electrical equipment is determined. Then, based on the target charging parameters corresponding to the target charging mode, the electrical equipment is charged. In this way, when there are multiple charging modes, the most suitable charging mode can be determined to charge the electrical equipment based on the charging demand information of the electrical equipment.

[0120] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0121] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0122] Figure 1 This is a schematic diagram of a charging device with energy storage units connected in series according to an embodiment of this application.

[0123] Figure 2 This is a schematic diagram of the structure of a charging device with an input module according to an embodiment of this application.

[0124] Figure 3 This is a schematic diagram of a charging device with energy storage units connected in parallel according to an embodiment of this application.

[0125] Figure 4A This 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] Figure 7 This is a schematic diagram of a charging device with a selection unit according to an embodiment of this application.

[0134] Figure 8 for Figure 7 The diagram shows a schematic of a charging device with a second positive power supply terminal.

[0135] 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.

[0136] 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.

[0137] Figure 10 for Figure 7 The diagram shows a charging device with multiple second positive power terminals.

[0138] Figure 11A for Figure 10 The diagram shows a charging device with multiple second positive power terminals and non-common negative charging guns.

[0139] Figure 11B for Figure 10 The diagram shows a charging device with multiple second positive power terminals and a common negative charging gun.

[0140] Figure 12A for Figure 7 The diagram shows a charging device with a selection unit and an input module including a ninth power conversion subunit.

[0141] Figure 12B for Figure 7 The diagram shows a charging device with a selection unit and an input module including multiple tenth power conversion sub-units.

[0142] Figure 13 This is a schematic diagram of the structure of a charging device with a wireless communication module according to an embodiment of this application.

[0143] Figure 14 This is a schematic diagram of a charging device according to an embodiment of the present application, in which energy storage units are connected in series, each energy storage unit includes a bidirectional DC-DC sub-unit and a charging gun with non-common negative charge.

[0144] Figure 15 This is a schematic diagram of a charging device according to an embodiment of the present application, in which energy storage units are connected in series, each energy storage unit including a bidirectional DC-DC sub-unit and a charging gun sharing the same charge.

[0145] Figure 16 This is a schematic diagram of a charging device according to one embodiment of the present application, in which energy storage units are connected in parallel, each energy storage unit includes a bidirectional DC-DC sub-unit and a charging gun with non-shared charge.

[0146] Figure 17 This is a schematic diagram of a charging device according to one embodiment of the present application, in which energy storage units are connected in parallel, each energy storage unit including a bidirectional DC-DC sub-unit and a charging gun sharing the same charge.

[0147] Figure 18 This is a schematic diagram of a charging device according to an embodiment of the present application, in which energy storage units are connected in series, some of which include bidirectional DC-DC sub-units, and the charging guns are not shared.

[0148] Figure 19This is a schematic diagram of a charging device according to one embodiment of the present application, in which energy storage units are connected in series and some energy storage units include bidirectional DC-DC sub-units and a charging gun sharing the same charge.

[0149] Figure 20 This is a schematic diagram of a charging device according to one embodiment of the present application, in which energy storage units are connected in parallel, each energy storage unit includes a first switch subunit and a charging gun that does not share a common load.

[0150] Figure 21 This is a schematic diagram of the structure of a charging device in one embodiment of this application, in which the energy storage unit and the bidirectional AC / DC subunit constitute a three-phase power supply and the charging guns do not share a common load.

[0151] Figure 22 This is a schematic diagram of the structure of a charging device comprising an energy storage unit and a bidirectional AC / DC subunit, which is a three-phase power supply and a common charge for the charging gun, according to one embodiment of this application.

[0152] Figure 23 This is a schematic diagram of the structure of a single battery cell provided for some embodiments of this application.

[0153] Figure 24 This is an exploded schematic diagram of a single battery cell provided for some embodiments of this application.

[0154] Figure 25 This is a schematic diagram of the structure of a battery module provided for some embodiments of this application.

[0155] Figure 26 This is a schematic diagram of the structure of a battery pack provided for some embodiments of this application.

[0156] Figure 27 This is a schematic diagram of the structure of an electrical device provided in some embodiments of this application.

[0157] Figure 28 This is a schematic diagram of the structure of a charging pile according to an embodiment of this application.

[0158] Figure 29 This is a schematic diagram of the structure of a charging and storage system according to an embodiment of this application.

[0159] Figure 30 This is a schematic diagram of the structure of a charging and storage system with multiple charging devices sharing a DC bus, according to one embodiment of this application.

[0160] Figure 31 This is a schematic diagram of the structure of a charging and storage system with multiple charging devices sharing a DC bus, according to another embodiment of this application.

[0161] Figure 32 This is a schematic diagram of the structure of a charging and storage system with multiple charging devices sharing an AC bus according to an embodiment of this application.

[0162] Figure 33 The composition structure of a charging system provided in this application embodiment Figure 1 .

[0163] Figure 34 The composition structure of a charging system provided in this application embodiment Figure 2 .

[0164] Figure 35 This application provides a schematic diagram of the implementation process of a charging method. Figure 1 .

[0165] Figure 36 This application provides a schematic diagram of the implementation process of a charging method. Figure 2 .

[0166] Figure 37 The present application provides an implementation flow of a charging method for an electric vehicle and a battery system module.

[0167] Figure 38A This is a schematic diagram of a charging mode powered by a single battery system, provided as an embodiment of this application.

[0168] Figure 38B This is a communication architecture diagram of a charging system provided in an embodiment of this application.

[0169] Figure 38C This is a schematic diagram of a charging mode in which the power grid replenishes the battery system module, as provided in an embodiment of this application.

[0170] Figure 38D This is a schematic diagram of a charging mode in which a battery system module and the power grid are powered together, as provided in an embodiment of this application.

[0171] Figure 38E This is a schematic diagram of a charging mode powered solely by the power grid, provided as an embodiment of this application.

[0172] Figure 39 This is a schematic diagram illustrating the implementation process of a method for supplying power from an electric vehicle and battery system module to the power grid, provided in an embodiment of this application.

[0173] Figure 40A This is a schematic diagram of a power supply mode for an electric vehicle to supply power to the power grid, provided as an embodiment of this application.

[0174] Figure 40B This is a schematic diagram illustrating a power supply mode for a battery system module to supply power to the power grid, as provided in an embodiment of this application.

[0175] Figure 41A A schematic diagram of the composition structure of a charging control device provided in an embodiment of this application. Figure 1 .

[0176] Figure 41B A schematic diagram of the composition structure of a charging control device provided in an embodiment of this application. Figure 2 .

[0177] Figure 41C A schematic diagram of the composition structure of a charging control device provided in an embodiment of this application. Figure 3 .

[0178] Figure 41D The fourth diagram illustrates the structural composition of a charging control device provided in this application embodiment.

[0179] Figure 41E Figure 5 shows the structural composition of a charging control device provided in an embodiment of this application.

[0180] Figure 41F Sixth is a schematic diagram of the composition structure of a charging control device provided in an embodiment of this application.

[0181] Figure 41G A schematic diagram of the composition structure of a charging control device provided in an embodiment of this application. Figure 7 .

[0182] The annotations in the attached figures are explained as follows:

[0183] 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;

[0184] 1. Electrical equipment; 2. Battery pack; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 5c. Storage space; 6. Battery module;

[0185] 7. Individual battery cell;

[0186] 10. Electrode assembly; 11. First electrode tab; 13. Second electrode tab; 12. Main body;

[0187] 20. Outer shell; 21. Housing; 22. End cap;

[0188] 31. First electrode terminal; 32. Second electrode terminal. Detailed Implementation

[0189] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0190] 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0191] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0192] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0193] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0194] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0195] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0196] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0197] Currently, with the rapid increase in electrical devices, problems such as slow charging and poor user experience urgently need to be addressed. In order to meet the charging needs of electrical devices in different scenarios, various charging modes have emerged. However, there is currently no good method to determine the appropriate charging mode for charging electrical devices.

[0198] Based on this, this application provides a charging system, including a charging device and an electrical device, wherein the charging device includes an energy storage device; the charging device is configured to determine the charging demand information of the electrical device in response to a charging event; based on the charging demand information, determine a target charging mode for the charging device to charge the electrical device, wherein the target charging mode corresponds to target charging parameters; the charging device includes an energy storage device; and the electrical device is charged based on the target charging parameters corresponding to the target charging mode; wherein, when the target charging mode includes a first charging mode, the target charging parameters corresponding to the first charging mode include a first charging parameter, and the charging power indicated by the first charging parameter is greater than 300 kilowatts. In the embodiments of this application, based on the charging demand information of the electrical device, a target charging mode for the charging device to charge the electrical device is determined, and then, based on the target charging parameters corresponding to the target charging mode, the electrical device is charged. This method can determine the most suitable charging mode for charging the electrical device based on the charging demand information of the electrical device when multiple charging modes exist.

[0199] The charging device disclosed in this application can be used to charge electric vehicles, electric ships, power tools and other devices that require fast charging / supercharging, as well as electric vehicles, electric ships, power tools and other devices that do not require fast charging / supercharging. In other words, the charging device disclosed in this application can charge electrical equipment at both high and low power levels, and has a wide range of applications.

[0200] The charging and storage system of this application will be described below with reference to specific embodiments.

[0201] Figure 1 This is a schematic diagram of the structure of a charging device 100 according to an embodiment of this application.

[0202] Reference Figure 1 The charging device 100 may include an energy storage module 110 and a charging module 120.

[0203] Energy storage module 110 includes one or more energy storage units, namely energy storage unit A1, ..., energy storage unit A n-1 and energy storage unit A n (n is a positive integer), each energy storage unit has a first positive power supply terminal (+) and a first negative power supply terminal (-), and one or more energy storage units are connected to the second positive power supply terminal (+) and the second negative power supply terminal (-) of the energy storage module 110 through the first positive power supply terminal and the first negative power supply terminal, and the energy storage module 110 is configured to provide a first direct current. As an example, the energy storage unit may be an electrical box.

[0204] The charging module 120 is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. The charging module 120 is configured to output charging power based on the first DC power. The maximum charging output power of the charging module 120 is greater than or equal to 350 kW, and / or the rated charging output power of the charging module 120 is greater than or equal to 290 kW.

[0205] Specifically, the number of energy storage units can be selected based on actual needs. When the charging device 100 is only used for low-power charging, one or a few energy storage units can be set, which can meet the needs of low-power charging applications. When the charging device 100 is used for high-power charging, multiple energy storage units can be set, which can meet both high-power and low-power charging applications. For example, adjusting the charging output power of the energy storage unit, the charging module, or both the energy storage unit and the charging module can achieve high-power or low-power charging. Due to the modularity of the energy storage units, they can be freely added or removed, enabling rapid connection and high-power charging without the need to add transformers or expand transformer capacity.

[0206] When there is only one energy storage unit, its first positive power supply terminal is connected to the second positive power supply terminal of the energy storage module 110, and its first negative power supply terminal is connected to the second negative power supply terminal of the energy storage module 110. The second positive and second negative power supply terminals of the energy storage module 110 are also connected to the charging module 120. During charging, the energy storage module 110 provides a first DC power supply through the energy storage unit, and the charging module 120 converts this first DC power supply to obtain the target DC power supply to charge the device. In this case, the charging device 100 can meet the needs of low-power charging applications. It should be noted that the relevant parameters of the energy storage unit and the charging module 120 can be set based on actual conditions; reasonable parameter configuration is sufficient to meet charging requirements.

[0207] When there are multiple energy storage units, they can be connected in series, parallel, or series-parallel configurations, and connected to the charging module 120 through the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. For example, in Figure 1 In this configuration, energy storage units A1, ..., An-1, and An are connected in series between the second positive and second negative power supply terminals of energy storage module 110 via their respective first positive and first negative power supply terminals. The second positive and second negative power supply terminals of energy storage module 110 are also connected to charging module 120. During charging, when high-power charging is required, energy storage module 110 provides a first DC power supply through multiple energy storage units. This first DC power supply can have high power. Then, charging module 120 converts this first DC power supply to obtain a target DC power supply with high power to charge the device. This target DC power supply has high power, thus meeting the needs of high-power charging applications. When low-power charging is required, both the first DC power supply and the target DC power supply have low power, thus meeting the needs of low-power charging applications. It should be noted that the relevant parameters of the energy storage units and charging module 120 can be set based on actual conditions, as long as the charging requirements are met through reasonable parameter configuration. When there are multiple energy storage units, the capacity of the energy storage module is the sum of the capacities of the multiple energy storage units.

[0208] 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 instance, by selecting an appropriate number of energy storage units, the maximum charging output power of the charging module 120 can reach 350 kW, 360 kW, 500 kW, 800 kW, and 900 kW, etc. It should be noted that the charging output power here refers to the maximum charging output power. In actual charging, it is backward compatible. For example, when the maximum charging output power is 360 kW, it means that the charging device 100 can output a charging output power of 0~360 kW to meet different charging needs.

[0209] It is understandable that the maximum charging output power of the charging module 120 and the rated charging output power satisfy a certain multiple relationship, such as a multiple relationship of 1.1 to 1.2. Therefore, the rated charging output power of the charging module 120 can be greater than or equal to 290 kilowatts, that is, the rated charging output power of the charging device 100 is greater than or equal to 290 kilowatts.

[0210] In practical applications, the maximum charging output power of the charging module 120 can be limited, the rated charging output power can be limited, or both can be limited simultaneously.

[0211] In the above embodiments, by configuring a modular energy storage unit inside the charging device, or by setting a modular energy storage unit and a modular charging unit outside the charging device, i.e., setting an energy storage module and a charging module outside the charging device, the energy storage unit and the charging unit can be freely added or removed. When high-power charging is required, the free and rapid access of the energy storage unit can not only achieve high-power charging, such as fast charging / supercharging, but also eliminate the need to add an extra transformer or expand the transformer capacity, thereby reducing transformer costs.

[0212] In some embodiments, refer to Figure 2 The charging device 100 also includes an input module 130, which is adapted to provide charging energy to each energy storage unit.

[0213] In one example, input module 130 can be an ACDC conversion unit.

[0214] 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 to the energy storage unit. In different power environments, whether it is an old urban area with relatively tight power supply or a remote area that is sensitive to the cost of infrastructure construction, the charging device, with the cooperation of the input module 130 and the energy storage module 110, uses the input module 130 to adjust the power supply parameters of the energy storage module 110, thereby achieving fast charging function without relying on external complex power supply upgrades, enhancing the applicability and flexibility of the charging device in various scenarios.

[0215] This allows the power grid to charge the energy storage unit through the input module 130.

[0216] In some embodiments, the maximum output power of the input module 130 is less than or equal to 150 kW, and / or the rated output power of the input module 130 is less than or equal to 125 kW.

[0217] Specifically, the input module 130 is mainly used to charge the various energy storage units in the energy storage module 110, and it charges at a low power during charging. For example, the maximum output power of the input module 130 is less than or equal to 150 kW, such as 150 kW, 100 kW, and 85 kW. It should be noted that the output power here refers to the maximum output power. In actual charging, it is backward compatible; for example, when the maximum output power is 150 kW, it means that an output power of 0~150 kW can be used to charge the various energy storage units in the energy storage module 110.

[0218] In this example, input module 130 provides low-power output, while charging module 120 provides high-power output. Therefore, the entire charging device 100 can achieve high-power output with low-power input. For example, the input terminal of the transformer is connected to the AC power grid, and the output terminal of the transformer is connected to input module 130. When the transformer is of small capacity, the maximum output power of input module 130 is limited by its capacity, such as a maximum output power of 150 kW. In this case, it charges the energy storage units in energy storage module 110 at a low power. However, when energy storage module 110 discharges to charge the device to be charged, high-power charging can be achieved based on multiple energy storage units, such as a maximum charging output power of 360 kW for charging module 120. Thus, high-power output with low-power input is achieved, enabling the charging device to meet high-power charging needs without adding an additional transformer or expanding its capacity. Those skilled in the art will understand that a power grid generally refers to a system that can provide electricity. As an example, a power grid can be a municipal power source.

[0219] It is understandable that the maximum output power of the input module 130 and the rated output power satisfy a certain multiple relationship, such as a multiple relationship of 1.1 to 1.2. Therefore, the rated output power of the input module 130 can be less than or equal to 125 kilowatts.

[0220] In practical applications, the maximum output power of the input module 130 can be limited, the rated output power can be limited, or both can be limited simultaneously.

[0221] In the above embodiments, by configuring a modular energy storage unit inside the charging device 100, the maximum output power and / or rated power of the input module 130 are limited to the aforementioned range, allowing the charging device 100 to flexibly connect to the power grid. Specifically, since the output power of most public power grids or commercial power interfaces is limited, the power setting of the input module 130 can smoothly obtain charging energy from the conventional power environment without modifying existing power supply lines, improving the access feasibility of the charging device 100 in various power consumption scenarios, thus facilitating the installation of the charging device 100; furthermore, it enables the charging device 100 to achieve high-power charging under low-power input, allowing the charging device 100 to meet high-power charging needs without adding an additional transformer or expanding its capacity. During peak electricity consumption periods, when multiple electrical devices are running simultaneously, the energy storage module supplies power to multiple electrical devices, and the input module 130 charges the energy storage unit stably at a lower power, effectively reducing the impact of the charging device 100 on the power grid during charging and helping to maintain the stability of the power grid.

[0222] 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.

[0223] Specifically, the maximum charging output power of the charging module 120 is greater than the maximum output power of the input module 130, meaning the ratio of the maximum charging output power of the charging module 120 to the maximum output power of the input module 130 is greater than 1. For example, the ratio can be greater than 2, 2.3, 3, 4, 8, or 12.5, thereby achieving high power output with low power input. For instance, when the ratio is 12.5, it means the maximum charging output power of the charging module 120 is 12.5 times the maximum output power of the input module 130. Assuming the maximum output power of the input module 130 is 40 kilowatts, then the maximum charging output power of the charging module 120 is greater than or equal to 500 kilowatts.

[0224] Meanwhile, the ratio of the maximum charging output power of the charging module 120 to the maximum output power of the input module 130 is less than or equal to 15. For example, it can be 15, 12.5, 10.3, 9, 7, or 6. For instance, when the ratio is 6, it means that the maximum charging output power of the charging module 120 is 6 times the maximum output power of the input module 130. Assuming that the maximum output power of the input module 130 is 150 kilowatts, then the maximum charging output power of the charging module 120 is less than or equal to 900 kilowatts.

[0225] It should be noted that when setting the above ratios, the minimum ratio is less than or equal to the maximum ratio. For example, the ratio between the maximum charging output power of the charging module 120 and the maximum output power of the input module 130 is greater than 2 and less than or equal to 15, or greater than 1 and less than or equal to 6, or greater than 6 and less than or equal to 12.5, etc. The specific setting should be selected according to actual needs.

[0226] Thus, 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, a high cost-performance ratio and good performance can be achieved while realizing high power output with low power input.

[0227] It is understandable that the maximum charging output power of the charging module 120 and the rated charging output power satisfy a certain multiple relationship, such as a multiple relationship of 1.1 to 1.2. At the same time, the maximum output power of the input module 130 and the rated output power satisfy a certain multiple relationship, such as a multiple relationship of 1.1 to 1.2. Therefore, the ratio between the rated charging output power of the charging module 120 and the rated output power of the input module 130 can also be greater than 1 and less than or equal to 15.

[0228] In practical applications, the ratio between the maximum charging output power of the charging module 120 and the maximum output power of the input module 130 can be limited, or the ratio between the rated charging output power of the charging module 120 and the rated output power of the input module 130 can be limited, or both can be limited simultaneously.

[0229] In the above embodiments, by limiting the ratio of the maximum charging output power of the charging module to the maximum output power of the input module, and / or limiting the ratio of the rated charging output power of the charging module to the rated output power of the input module, on the one hand, problems such as current surges and overheating caused by instantaneous excessive power input to the charging module 120 can be reduced. On the other hand, the input module 130 can charge the energy storage module 110 with low power, and the energy storage module can then output controllable high power to the charging module 120, realizing low power input to the energy storage module 110 and high power output from the charging module 120. In addition, the energy storage module 110 can flexibly adjust its output power according to its stored power and the power demand of the electrical equipment, so that the charging device 100 can rationally allocate electrical energy, reduce unnecessary energy consumption, improve the cost-effectiveness of the charging device 100, and enable the charging device 100 to operate smoothly when low power input and high power output are achieved.

[0230] In some embodiments, each energy storage unit includes a battery sub-unit, and the ratio between the rated output power of the input module 130 and the rated energy of the battery sub-unit is greater than or equal to 1 / n1, wherein the value of n1 ranges from 1 to 4.

[0231] Specifically, the rated energy of a battery sub-cell refers to the energy capacity specified in the design of the battery sub-cell. It represents the maximum energy value that the battery sub-cell can store or output under normal operating conditions, measured in kilowatt-hours. The rated output power of the input module 130 is greater than or equal to the rated energy of the battery sub-cell divided by the coefficient n1 / 100%, where n1 can be 1, 1.4, 2, 3, or 4, etc. By specifying that the rated output power of the input module must be greater than the rated energy of the battery sub-cell divided by the coefficient n1, the rated energy of the battery sub-cell is lower when the input power of the input module 130 is lower. This ensures that the input power and the rated energy of the battery sub-cell are matched, preventing the input module 130 from charging the battery sub-cell too slowly and affecting the use of the energy storage unit. Simultaneously, specifying a lower rated energy of the battery sub-cell also indicates a smaller battery sub-cell size, resulting in a smaller footprint for the energy storage unit and easier installation. This further enables a small-volume energy storage unit, achieving high power output from low power input and improving the user experience.

[0232] 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 120 is greater than or equal to 1 / (n2*n3), wherein the value of n2 ranges from 94% to 99%, and the value of n3 ranges from 4 to 6.

[0233] In other words, the rated energy of the battery sub-unit 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%, or 99%, and n3 can be 4, 5, 5.5, or 6. This setting ensures both charging performance and the reliability of the charging device 100. When the rated energy of the battery sub-unit matches the rated charging output power of the charging module 120, the battery sub-unit can stably provide energy to the charging module 120 during charging, reducing the risk of unstable or interrupted charging power due to insufficient energy supply. Taking n2 as 94% and n3 as 6 as an example, the larger denominator requires the battery sub-unit to have a relatively high rated energy to match the power of the charging module 120. This allows the charging device 100 to operate stably during long-term, high-power charging, reducing the probability of failure, lowering maintenance costs, extending the service life of the charging device 100, and improving its cost-effectiveness.

[0234] In some embodiments, each energy storage unit includes a battery sub-cell, wherein the ratio between the rated energy and the rated power of the battery sub-cell is less than or equal to 1 / 3, and / or the volumetric energy density of the battery sub-cell is greater than 380 Wh / L.

[0235] In other words, the ratio of the rated energy to the rated power of the battery sub-unit should not exceed 1:3. For example, when the rated power of the battery sub-unit is 350 kW and the rated energy of the battery sub-unit is 58 kW, this setting can improve the cost-effectiveness of the entire charging device.

[0236] The volumetric energy density of the battery sub-cell is greater than or equal to 380 Wh / L, for example, it could be 380 Wh / L, 400 Wh / L, 600 Wh / L, or 900 Wh / L. Understandably, the higher the energy density of the battery sub-cell, the smaller its volume, thus saving space and reducing construction costs, while still providing high power output.

[0237] When the charging device 100 outputs high power (the maximum charging output power of the charging module is above 350kW), 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 380 Wh / L. This ensures that the rated energy of the battery sub-unit matches the rated power, reducing grid fluctuations caused by insufficient rated energy of the battery sub-unit due to high power output, which is beneficial to improving the reliability and stability of the charging device 100. Furthermore, it enables the charging device 100 to operate continuously and stably at high power output, reducing the probability of failure, lowering maintenance costs, and thus extending the service life of the charging device 100 and improving its cost-effectiveness.

[0238] In some embodiments, each energy storage unit includes a battery sub-cell with a maximum discharge rate greater than or equal to 4 times, for example, a maximum discharge rate greater than or equal to 5 times, 6 times, 7 times, or 8 times. This enables the provision of high power output.

[0239] It should be noted that the above parameters can be superimposed. For example, when the maximum charging output power of the charging module 120 is greater than or equal to 350 kW, the maximum output power of the battery sub-unit is greater than or equal to 350 kW, the rated power of the battery sub-unit is greater than or equal to 350 kW, the rated energy of the battery sub-unit is greater than or equal to 58 kW, the maximum discharge rate of the battery sub-unit is greater than or equal to 4 times, and the maximum output power of the input module 130 can be less than or equal to 150 kW.

[0240] It should be noted that the aforementioned parameters concerning battery sub-units also apply to energy storage units and / or energy storage modules in some cases. In other words, in some situations, the above parameters apply to energy storage units, energy storage modules, and battery sub-units. For example, when an energy storage unit includes only a battery sub-unit, the relevant parameters of that battery sub-unit are also the relevant parameters of the energy storage unit. Furthermore, when the energy storage module 110 includes one energy storage unit, the relevant parameters of that battery sub-unit are also the relevant parameters of the energy storage module 110; and so on.

[0241] It should be noted that the energy storage unit may include one or more battery sub-cells, which can be connected in series, parallel, or series-parallel. Each battery sub-cell can be a single cell, or multiple single cells connected in series, parallel, or series-parallel. For example, a single cell may include 10 to 100 cells, and combining these cells can yield 2 to 6 battery sub-cells. These 2 to 6 sub-cells can be connected in series and / or parallel, allowing the energy storage unit to achieve a capacity of 80 kWh to 150 kWh. For instance, 80 kWh can be achieved by combining 2 single cells; 150 kWh by combining 100 single cells; 90 kWh by combining 80 single cells; and so on.

[0242] In the above embodiments, by limiting the ratio of the rated energy and 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 achieve a high cost-performance ratio.

[0243] In some embodiments, one or more energy storage units are connected in series and / or in parallel between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 via a first positive power supply terminal and a first negative power supply terminal to provide a first direct current.

[0244] Specifically, when there is only one energy storage unit, the first positive power supply terminal of the energy storage unit is connected to the second positive power supply terminal of the energy storage module 110, and the first negative power supply terminal of the energy storage unit is connected to the second negative power supply terminal of the energy storage module 110, so as to provide the first DC power through the energy storage unit.

[0245] When there are multiple energy storage units, these units can be connected in series, in parallel, or a combination of series and parallel. For example, refer to... Figure 1 Multiple energy storage units are connected in series between the second positive and second negative power supply terminals of the energy storage module 110 via their own first positive and first negative power supply terminals; for example, referring to Figure 3 Multiple energy storage units are connected in parallel between the second positive and second negative power supply terminals of the energy storage module 110 via their own first positive and first negative power supply terminals; alternatively, multiple energy storage units can be connected in series first and then in parallel, or in parallel first and then in series, between the second positive and second negative power supply terminals of the energy storage module 110. The first DC power is provided by connecting multiple energy storage units in series, parallel, or series-parallel configurations. The specific connection method can be selected based on the actual situation.

[0246] In the above embodiments, multiple energy storage units can be connected in series, parallel, or series-parallel configurations, allowing for flexible access of energy storage units to meet different charging power requirements.

[0247] In some embodiments, refer to Figures 4A-4D Each energy storage unit includes a battery sub-unit, and each energy storage unit is configured to provide a second DC power based on the electrical energy of the battery sub-unit.

[0248] For example, refer to Figure 4A Energy storage unit A1 includes battery sub-units BAT1, ..., energy storage unit A n-1 Including battery sub-unit BAT n-1 Energy storage unit A n Including battery sub-unit BAT n Each energy storage unit provides a second DC power based on the electrical energy of the battery sub-unit, and multiple energy storage units provide a first DC power to the charging module 120 through series and / or parallel connection.

[0249] In some embodiments, refer to Figure 4BAt least some of the energy storage units in one or more energy storage units further include a first power conversion subunit, which is connected to a first positive power supply terminal and a first negative power supply terminal of the corresponding battery subunit and energy storage unit, respectively, and is configured to convert the electrical energy of the battery subunit into a second direct current; wherein, in the case where the energy storage unit does not include the first power conversion subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current.

[0250] Specifically, when there is only one energy storage unit, the energy storage unit also includes a first power conversion subunit to convert the electrical energy of the battery subunit into a second direct current.

[0251] When there are multiple energy storage units, a first power conversion subunit can be set in each of the multiple energy storage units, or a first power conversion subunit can be set in some of the multiple energy storage units. For example, in Figure 4B In 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.

[0252] 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.

[0253] 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.

[0254] In some embodiments, refer to Figure 4C At least some of the energy storage units in one or more energy storage units further include a first switching subunit, which is connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding battery subunit and the energy storage unit, respectively, and is configured to connect the corresponding battery subunit to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit when the battery is turned on, so as to provide a second DC power; wherein, when the energy storage unit does not include the first switching subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second DC power.

[0255] Specifically, when there is only one energy storage unit, the energy storage unit also includes a first switching subunit. When the first switching subunit is turned on, the battery subunit is connected to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit to provide a second DC power. In abnormal situations, such as abnormalities in the battery subunit or the charging module 120, the first switching subunit is turned off to reduce the occurrence of further abnormal accidents. When the battery subunit does not need to work, such as when the energy storage unit does not need to work based on power requirements, the first switching subunit is turned off to stop the battery unit from providing the second DC power.

[0256] When there are multiple energy storage units, a first switching subunit can be set in each of the multiple energy storage units, or a first switching subunit can be set in some of the multiple energy storage units. For example, in Figure 4C In the above, energy storage unit A1 includes a battery subunit BAT1 and a first switching subunit C1. The first switching subunit C1 is connected to the first positive power supply terminal and the first negative power supply terminal of the battery subunit BAT1 and energy storage unit A1, respectively. The first switching subunit C1 controls the switching on and off of the first positive power supply terminal and the first negative power supply terminal of the battery subunit BAT1 and energy storage unit A1 to selectively provide a second DC power;...; Energy storage unit A n-1 Including battery sub-unit BAT n-1 and the first switch subunit C n-1 First switch subunit C n-1 Each with battery sub-cell BAT n-1 and energy storage unit A n-1The first positive power supply terminal and the first negative power supply terminal are connected through the first switch subunit C. n-1 Control battery sub-cell BAT n-1 With energy storage unit A n-1 The switching of the first positive power supply terminal and the first negative power supply terminal selectively provides a second DC power supply; 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.

[0257] In the above embodiments, some or all of the multiple energy storage units may be equipped with a first switching subunit. The first switching subunit selectively controls the battery subunit to provide a second DC power, thereby improving the charging flexibility and protection in abnormal situations.

[0258] In some embodiments, refer to Figure 4D At least some of the energy storage units in one or more energy storage units further include a first power conversion subunit and a first switching subunit, the first power conversion subunit and the first switching subunit being connected in series between a first positive power supply terminal and a first negative power supply terminal of the corresponding battery subunit and energy storage unit, the first power conversion subunit being configured to convert the electrical energy of the battery subunit into a second direct current when the corresponding first switching subunit is turned on; wherein, in the case where the energy storage unit does not include the first power conversion subunit and the first switching subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second direct current.

[0259] Specifically, when there is only one energy storage unit, the energy storage unit also includes a first power conversion subunit and a first switching subunit. When the first switching subunit is turned on, the first power conversion subunit converts the electrical energy of the battery subunit into second DC power. In abnormal situations, such as abnormalities in the battery subunit or charging module 120, the first switching subunit is turned off, and the first power conversion subunit stops working to reduce the occurrence of further abnormal accidents. When the battery subunit does not need to work, such as when the energy storage unit does not need to work based on power requirements, the first switching subunit is turned off, and the first power conversion subunit stops working so that the battery subunit stops providing second DC power.

[0260] When there are multiple energy storage units, a first switching subunit and a first power conversion subunit can be set in each of the multiple energy storage units, or a first switching subunit and a first power conversion subunit can be set in some of the multiple energy storage units. For example, in Figure 4DIn the energy storage unit A1, there are battery sub-units BAT1, a first switching sub-unit C1, and a first power conversion sub-unit B1. The first switching sub-unit C1 and the first power conversion sub-unit B1 are connected in series between the first positive power supply terminal and the first negative power supply terminal of the battery sub-unit BAT1 and the energy storage unit A1. When the first switching sub-unit C1 is turned on, the first power conversion sub-unit B1 converts the electrical energy of the battery sub-unit BAT1 into a second direct current;...; Energy storage unit A n-1 Including battery sub-unit BAT n-1 First switch subunit C n-1 and the first power conversion subunit B n-1 First switch subunit C n-1 and the first power conversion subunit B n-1 Connected in series in the battery sub-cell BAT n-1 and energy storage unit A n-1 Between the first positive power supply terminal and the first negative power supply terminal, in the first switch subunit C n-1 When the circuit is on, 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.

[0261] It should be noted that in some embodiments, a portion of the energy storage unit may include a first switching subunit, and another portion may include a first power conversion subunit; no specific limitation is made here.

[0262] In the above embodiments, some or all of the multiple energy storage units may be equipped with a first switching subunit and a first power conversion subunit, thereby improving the charging flexibility and protection capability under abnormal conditions.

[0263] In some embodiments, the first power conversion subunit is a bidirectional DC-DC subunit, which enables the charging and discharging of the battery subunit. This bidirectional DC-DC subunit includes, but is not limited to, a BUCK-BOOST circuit, etc., and is not specifically limited here.

[0264] In some embodiments, refer to Figure 5A The input module 130 includes an input interface (X, Y), which is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. It is configured to provide charging energy to each energy storage unit based on the third DC power supplied by the first external power supply 210.

[0265] Specifically, the first external power source 210 generates a third direct current (DC) and transmits it to the energy storage module 110 via an input interface to charge the various energy storage units within the energy storage module 110. For example, the first external power source 210 may include a first transformer and a first AC / DC conversion module. The primary winding of the first transformer is connected to the AC power grid to convert the second AC power provided by the AC power grid into the first AC power. The first AC / DC conversion module is connected to the secondary winding of the first transformer and the input interface to convert the first AC power into the third DC power, which is then transmitted to the energy storage module 110 via the input interface.

[0266] The first AC / DC conversion module can be a unidirectional AC / DC sub-unit or a bidirectional AC / DC sub-unit. When the first AC / DC conversion module is a bidirectional AC / DC sub-unit, it can not only charge the energy storage module 110, but also feed the electrical energy of the energy storage module 110 to the AC power grid. The specific circuit structure of the unidirectional or bidirectional AC / DC sub-unit is not limited here.

[0267] It should be noted that in this example, the maximum output power and rated output power of the input module 130 are also the maximum output power and rated output power of the first external power supply 210.

[0268] In the above embodiments, when an external power source provides DC power, the battery sub-unit can be charged through the input interface.

[0269] In some embodiments, refer to Figure 5B The input module 130 includes a second power conversion subunit 131, which is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 and is configured to provide charging energy to each energy storage unit based on the first AC power provided by the second external power supply 220.

[0270] Specifically, the second external power source 220 generates first alternating current (AC) and provides it to the second power conversion subunit 131 in the input module 130. The second power conversion subunit 131 then charges the various battery subunits in the energy storage module 110. For example, the second external power source 220 may include a first transformer, the primary winding of which is connected to the AC power grid. The second power conversion subunit 131 is connected to both the secondary winding of the first transformer and the energy storage module 110. The first transformer converts the second AC power provided by the AC power grid into first AC power, which is then provided to the second power conversion subunit 131. The second power conversion subunit 131 then converts the first AC power into third direct current (DC) to charge the energy storage module 110.

[0271] The second power conversion subunit 131 can be a unidirectional AC-CDC subunit or a bidirectional AC-CDC subunit. When the second power conversion subunit 131 is a bidirectional AC-CDC subunit, it can not only charge the energy storage module 110, but also feed the power of the energy storage module 110 to the AC grid. The specific circuit structure of the unidirectional or bidirectional AC-CDC subunit is not limited here.

[0272] It should be noted that in this example, the maximum output power and rated output power of the input module 130 are also the maximum output power and rated output power of the second power conversion subunit 131.

[0273] In the above embodiments, when an external power source provides AC power, the battery sub-unit can be charged through the second power conversion sub-unit.

[0274] In some embodiments, please refer to Figure 6A , 6B 9A, 9B, 11A, 11B and Figures 14-22 The charging module 120 includes a charging module conversion unit and at least one charging gun 122, which is connected to the energy storage module 110 through the charging module conversion unit.

[0275] 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. They can charge the same electrical device at the same time, which can be an electric vehicle. Each charging gun 122 can also charge different electrical devices individually.

[0276] When there are multiple charging guns 122, they can be connected to the energy storage module 110 through the same charging module conversion unit. Each charging gun 122 can also be connected to the energy storage module 110 individually through a separate charging module conversion unit. The charging module conversion unit can be a DC-DC converter, specifically a unipolar unidirectional DC-DC converter, a unipolar bidirectional DC-DC converter, or a bipolar unidirectional DC-DC converter.

[0277] The charging module conversion unit can flexibly adjust parameters such as voltage and current according to the DC power output from the energy storage module 110 and the needs of the devices connected to the charging gun 122 (such as electric vehicles) to achieve efficient charging output. The configuration of at least one charging gun 122 allows the charging device 100 to charge one or more electrical devices simultaneously. In public charging areas, such as parking lots and charging stations, multiple users can simultaneously use different charging guns 122 to charge their electric vehicles, improving the utilization efficiency and service capacity of the charging device 100, meeting the requirements of large-scale charging demand scenarios, effectively alleviating charging queuing problems, and enhancing the user experience.

[0278] In some embodiments, refer to Figure 6A The charging module 120 includes a third power conversion subunit 121 and a charging gun 122. The positive and negative input terminals of the third power conversion subunit 121 are connected to the second positive and second negative power supply terminals of the energy storage module 110, respectively. The positive and negative output terminals of the third power conversion subunit 121 are connected to the positive and negative input terminals of the charging gun 122, respectively. The third power conversion subunit 121 is configured to convert the first DC power into a fourth DC power and output it for charging through the charging gun 122.

[0279] Specifically, when charging the device to be charged, one or more energy storage units provide a second DC power, thereby enabling the energy storage module 110 to provide a first DC power. This first DC power is converted into a fourth DC power by the third power conversion subunit 121 and provided to the charging gun 122, which then provides the charging device to be charged.

[0280] In this example, the third power conversion subunit 121 is bipolar, meaning it has a positive input terminal and a negative input terminal. The positive and negative input terminals of the third power conversion subunit 121 are directly connected to the second positive and second negative power supply terminals of the energy storage module 110. The positive and negative output terminals of the third power conversion subunit 121 are directly connected to the positive and negative input terminals of the charging gun 122. The negative input terminal of the charging gun 122 and the second negative power supply terminal of the energy storage module 110 are not shared. This design is suitable for application scenarios where the third power conversion subunit 121 is bipolar.

[0281] The third power conversion subunit 121 can be a bipolar unidirectional DC-DC subunit or a bipolar bidirectional DC-DC subunit. When the third power conversion subunit 121 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 can also 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.

[0282] In some embodiments, refer to Figure 6B The charging module 120 includes a fourth power conversion subunit 123 and a charging gun 122. The positive input terminal of the fourth power conversion subunit 123 is connected to the second positive power supply terminal of the energy storage module 110, the positive output terminal of the fourth power conversion subunit 123 is connected to the positive input terminal of the charging gun 122, and the negative input terminal of the charging gun 122 is connected to the second negative power supply terminal of the energy storage module 110. The fourth power conversion subunit 123 is configured to convert the first DC power into the fourth DC power and output it through the charging gun 122.

[0283] Specifically, when charging the device to be charged, one or more energy storage units provide a second DC power, thereby enabling the energy storage module 110 to provide a first DC power. This first DC power is converted into a fourth DC power by the fourth power conversion subunit 123 and provided to the charging gun 122, which then provides the device to be charged to charge it.

[0284] In this example, the fourth power conversion subunit 123 is unipolar, meaning it only has a positive input terminal. In this case, the positive input terminal of the fourth power conversion subunit 123 is directly connected to the second positive power supply terminal of the energy storage module 110, the positive output terminal of the fourth power conversion subunit 123 is directly connected to the positive input terminal of the charging gun 122, and the negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110. That is, the negative input terminal of the charging gun 122 and the second negative power supply terminal of the energy storage module 110 are shared. This design is suitable for application scenarios where the fourth power conversion subunit 123 is unipolar and is cost-effective.

[0285] The fourth power conversion subunit 123 can be a unipolar unidirectional DC-DC subunit or a unipolar bidirectional DC-DC subunit. When the fourth power conversion subunit 123 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 can also feed it to the AC power grid in the aforementioned example through the input module 130, ultimately realizing the free conversion of power between the grid, charging and storage.

[0286] In the above embodiments, by sharing or not sharing the negative input terminal of the charging gun, it can be applied to different power supply scenarios, thereby increasing the range of choices when selecting circuit structure.

[0287] In some embodiments, refer to Figure 7 The energy storage module 110 also includes a selection unit 111, which is connected to one or more energy storage units and configured to select at least one energy storage unit from the one or more energy storage units and connect it to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110 to provide a first DC power.

[0288] Specifically, during charging, selection unit 111 can select one energy storage unit A1 to connect to the second positive power supply terminal and the second negative power supply terminal of energy storage module 110 to provide the first DC power; or, it can select all energy storage units A1, ..., energy storage unit A n-1 and energy storage unit A n The first DC power supply is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110. Then, the charging module 120 outputs a charge based on the first DC power supply.

[0289] In the above embodiments, by selectively controlling the output of the energy storage unit through the selection unit, the charging flexibility can be improved to meet different charging needs.

[0290] In some embodiments, refer to Figure 8 The energy storage module 110 includes one second positive power supply terminal and one second negative power supply terminal. The selection unit 111 includes multiple second switch sub-units. Each second switch sub-unit is connected to 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 110. The first negative power supply terminals of one or more energy storage units are respectively connected to the second negative power supply terminal of the energy storage module 110. The second switch sub-unit is configured to connect the first positive power supply terminal of the corresponding energy storage unit to the second positive power supply terminal of the energy storage module 110 when it is turned on.

[0291] Specifically, the selection unit 111 includes a second switch subunit K1, ..., a second switch subunit Kn-1, and a second switch subunit Kn, wherein the second switch subunit K1 is connected in series between the first positive power supply terminal of the energy storage unit A1 and the second positive power supply terminal of the energy storage module 110, ..., the second switch subunit Kn-1 is connected in series between the energy storage unit A1 and the second positive power supply terminal of the energy storage module 110. n-1 Between the first positive power supply terminal and the second positive power supply terminal of the energy storage module 110, the second switching subunit Kn is connected in series in the energy storage unit A. n The first positive power supply terminal is connected to the 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 the fourth DC power to charge the device to be charged.

[0292] In the above embodiments, by setting a second positive power supply terminal and selectively controlling the energy storage unit to provide a second DC power through the selection unit, the charging flexibility can be improved and the charging demand can be met.

[0293] In some embodiments, refer to Figure 9AThe charging module 120 includes a fifth power conversion subunit 124 and a charging gun 122. The positive and negative input terminals of the fifth power conversion subunit 124 are connected to the second positive and second negative power supply terminals of the energy storage module 110, respectively. The positive and negative output terminals of the fifth power conversion subunit 124 are connected to the positive and negative input terminals of the charging gun 122, respectively. The fifth power conversion subunit 124 is configured to convert the first DC power into a fourth DC power and output it for charging through the charging gun 122.

[0294] It should be noted that for the connection relationship between the fifth power conversion subunit 124, the charging gun 122, and the energy storage module 110, as well as the structure of the fifth power conversion subunit 124, please refer to the aforementioned description of the third power conversion subunit 121. Further details will not be repeated here.

[0295] In some embodiments, refer to Figure 9B The charging module 120 includes a sixth power conversion subunit 125 and a charging gun 122. The positive input terminal of the sixth power conversion subunit 125 is connected to the second positive power supply terminal of the energy storage module 110, the positive output terminal of the sixth power conversion subunit 125 is connected to the positive input terminal of the charging gun 122, and the negative input terminal of the charging gun 122 is connected to the second negative power supply terminal of the energy storage module 110. The sixth power conversion subunit 125 is configured to convert the first DC power into a fourth DC power and output it for charging through the charging gun 122.

[0296] It should be noted that for the connection relationship between the sixth power conversion subunit 125, the charging gun 122, and the energy storage module 110, as well as the structure of the sixth power conversion subunit 125, please refer to the aforementioned description of the fourth power conversion subunit 123. Further details will not be repeated here.

[0297] In some embodiments, refer to Figure 10 The energy storage module 110 includes multiple second positive power terminals and one second negative power terminal. The selection unit 111 includes multiple second switch sub-units. Each second switch sub-unit is connected to an energy storage unit and a second positive power terminal. Each second switch sub-unit is connected in series between the first positive power terminal and the corresponding second positive power terminal of the corresponding energy storage unit. The first negative power terminals of one or more energy storage units are respectively connected to the second negative power terminal of the energy storage module 110. The second switch sub-unit is configured to connect the first positive power terminal of the corresponding energy storage unit to the corresponding second positive power terminal when the module is on.

[0298] Specifically, the selection unit 111 includes a second switching subunit K1, ..., a second switching subunit Kn-1, and a second switching subunit Kn, wherein the second switching subunit K1 is connected in series between the first positive power supply terminal of the energy storage unit A1 and a second positive power supply terminal of the energy storage module 110, ..., the second switching subunit Kn-1 is connected in series between the energy storage unit A1 and a second positive power supply terminal of the energy storage module 110. n-1 Between the first positive power supply terminal and the other second positive power supply terminal of the energy storage module 110, the second switching subunit Kn is connected in series in the energy storage unit A. n The 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.

[0299] 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.

[0300] 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.

[0301] 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-1and 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.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] In the above embodiments, by sharing or not sharing the negative input terminal of the charging gun, it can be applied to different power supply scenarios, thereby increasing the range of choices when selecting circuit structure.

[0309] In some embodiments, refer to Figure 12A The input module 130 includes a ninth power conversion subunit 132, which is connected to one or more energy storage units and is configured to provide charging energy to each energy storage unit based on a first AC power supplied by a second external power source 220.

[0310] Specifically, the second external power source 220 generates first alternating current (AC) and provides it to the ninth power conversion subunit 132 in the input module 130. The ninth power conversion subunit 132 then charges the various battery subunits in the energy storage module 110. For example, the second external power source 220 may include a second transformer. The primary winding of the second transformer is connected to the AC power grid, and the secondary winding of the second transformer is connected to the ninth power conversion subunit 132. The second transformer converts the second AC power provided by the AC power grid into first AC power, which is then provided to the ninth power conversion subunit 132. The ninth power conversion subunit 132 then converts the first AC power into third direct current (DC) to charge the energy storage module 110.

[0311] For example, the second external power supply 220 is a three-phase AC power supply, and the ninth power conversion subunit 132 is a unidirectional three-phase AC-CDC subunit or a bidirectional three-phase AC-CDC subunit. In this case, each phase of the three-phase AC-CDC 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 AC-CDC subunit, it can not only charge the energy storage module 110, but also feed the power of the energy storage module 110 to the AC power grid. Thus, in the three-phase AC power, each phase is implemented by an energy storage unit, and the three energy storage units can realize the function of three-phase AC power, for example, three-phase power frequency AC power with a phase difference of 120°. The specific circuit structure of this unidirectional three-phase AC-CDC subunit or bidirectional three-phase AC-CDC subunit is not limited here.

[0312] It should be noted that in this example, the maximum output power and rated output power of the input module 130 are also the maximum output power and rated output power of the ninth power conversion subunit 132.

[0313] In the above embodiments, when an external power source provides AC power, the battery sub-unit can be charged through the ninth power conversion sub-unit.

[0314] In some embodiments, refer to Figure 12B The input module 130 includes multiple tenth power conversion sub-units, each of which is connected to an energy storage unit. The multiple tenth power conversion sub-units are configured to provide charging energy to each energy storage unit based on the first AC power provided by the second external power source 220.

[0315] Specifically, the multiple tenth power conversion sub-units are tenth power conversion sub-unit F1, ..., tenth power conversion sub-unit F n-1 Tenth power conversion subunit F n Among them, the tenth power conversion subunit F1 is connected to the second external power source 220 and the energy storage unit A1 respectively, ..., the tenth power conversion subunit F n-1 Connected to the second external power supply 220 and energy storage unit A respectively n-1 Connected, the tenth power conversion subunit F n Connected to the second external power supply 220 and energy storage unit A respectively n Connected. Each tenth power conversion subunit can charge the corresponding energy storage unit based on the first AC power provided by the second external power source 220.

[0316] For example, the second external power supply 220 is a three-phase AC power supply, and the tenth power conversion subunit includes three subunits. Each tenth power conversion subunit is either a unidirectional single-phase AC-CDC subunit or a bidirectional single-phase AC-CDC subunit. In this case, each tenth power conversion subunit is connected to one phase of the three-phase AC power supply to charge the corresponding energy storage unit. When the tenth power conversion subunit is a bidirectional single-phase AC-CDC subunit, it can not only charge the energy storage module 110, but also feed the energy of the energy storage module 110 to the AC power grid. During feeding, the three bidirectional single-phase AC-CDC subunits cooperate with each other to form a three-phase AC power supply to the three-phase AC power grid. Thus, in the three-phase AC power, each phase is implemented by an energy storage unit, and the three energy storage units can realize the function of three-phase AC power. The specific circuit structure of the unidirectional single-phase AC-CDC subunit or the bidirectional single-phase AC-CDC subunit is not limited here.

[0317] It should be noted that, in this example, the maximum output power and rated output power of the input module 130 are the sum of the maximum output power and rated output power of the multiple tenth power conversion sub-units.

[0318] In the above embodiments, when an external power source provides AC power, the battery sub-unit can be charged through multiple tenth power conversion sub-units.

[0319] In some embodiments, refer to Figure 13 The charging device 100 also includes a wireless communication module 140. At least a portion of the energy storage module 110, the input module 130, and the charging module 120 are connected to the wireless communication module 140 to interact with external devices via the wireless communication module 140.

[0320] It should be noted that the above embodiments provide various charging device architectures. For example, multiple energy storage units can be connected in series, in parallel, or in a series-parallel configuration; some or all of the multiple energy storage units can be configured with a first power conversion subunit, a first switching subunit, or both; the charging module can employ a unipolar or bipolar power conversion subunit, and the negative input terminals of the corresponding charging piles can be shared or not; in three-phase AC power, a single phase is implemented using an energy storage unit, and three energy storage units can realize the function of three-phase AC power; the input module can be AC ​​input or DC input; and so on.

[0321] To enable those skilled in the art to better understand this application, specific examples are provided below, but these should not be construed as limiting the scope of this application.

[0322] Example 1, see reference Figure 14 The energy storage module 110 includes multiple energy storage units, each including a battery sub-unit and a first power conversion sub-unit. The first power conversion sub-unit can be a bidirectional DC-DC converter sub-unit. Multiple energy storage units are connected in series between the second positive power terminal and the second negative power terminal of the energy storage module 110, and the second positive power terminal and the second negative power terminal of the energy storage module 110 are connected to a DC bus. The charging module 120 includes a third power conversion sub-unit 121 and a charging gun 122. The third power conversion sub-unit 121 has a high-voltage positive input terminal and a high-voltage negative input terminal, as well as a high-voltage positive output terminal and a high-voltage negative output terminal. The third power conversion sub-unit 121 can be a bipolar bidirectional DC-DC converter sub-unit. The input module 130 includes a second power conversion sub-unit 131, which can be a bidirectional AC-DC converter sub-unit. The second external power supply 220 includes a first transformer connected to the AC power grid.

[0323] When charging the energy storage module 110, the first transformer converts the second AC power provided by the AC grid into the first AC power, which is then converted into DC power by the bidirectional AC-DC sub-unit and charged to each battery sub-unit in the energy storage module 110 through the DC bus.

[0324] When charging the device to be charged, the energy storage unit provides a second DC power based on the electrical energy of the battery sub-unit. The energy storage module 110 obtains a first DC power based on the second DC power. The first DC power is converted into a fourth DC power by the high-power bipolar bidirectional DC-DC sub-unit and then charged to the device to be charged through the charging gun 122 to achieve high-power charging, thereby realizing fast charging / supercharging of the device to be charged.

[0325] Understandably, with the help of the bidirectional AC-CDC subunit and the bipolar bidirectional DC-CDC subunit, the electrical energy of the device to be charged can also be fed to the energy storage module 110 or the AC grid, thereby realizing the free switching of electrical energy between the device to be charged, the energy storage module 110 and the AC grid.

[0326] Example 2, see reference Figure 15 This example is compared to Figure 14 The example shown differs in that the fourth power conversion subunit 123 only has a high-voltage positive input terminal and a high-voltage positive output terminal, while the high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110. That is, the charging gun 122 and the negative terminal of the energy storage module 110 are shared. This fourth power conversion subunit 123 can be a unipolar bidirectional DC-DC subunit. For the same content, further details are omitted here to avoid redundancy.

[0327] Example 3, see reference Figure 16 This example is compared to Figure 14 The example shown differs in that multiple energy storage units are connected in parallel between the second positive power supply terminal and the second negative power supply terminal of the energy storage module 110, that is, multiple energy storage units are connected in parallel to the DC bus.

[0328] Example 4, see reference Figure 17 This example is compared to Figure 16 The example shown differs in that the fourth power conversion subunit 123 has only a high-voltage positive input terminal and a high-voltage positive output terminal, and the high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110. That is, the negative terminal of the charging gun 122 and the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DC-DC subunit.

[0329] Example 5, see reference Figure 18 This example is compared to Figure 14 The example shown differs in that some energy storage units in the multiple energy storage units include battery sub-units, while other energy storage units include both battery sub-units and a first power conversion sub-unit. For example, energy storage unit A1 includes battery sub-units, and energy storage unit A... n Includes battery sub-units and bidirectional DC-DC sub-unit A n .

[0330] Example 6, see reference Figure 19 This example is compared to Figure 18 The example shown differs in that the fourth power conversion subunit 123 has only a high-voltage positive input terminal and a high-voltage positive output terminal, and the high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110. That is, the negative terminal of the charging gun 122 and the energy storage module 110 are shared. The fourth power conversion subunit 123 can be a unipolar bidirectional DC-DC subunit.

[0331] Example 7, see reference Figure 20 This example is compared to Figure 16 The example shown differs in that each energy storage unit includes a battery sub-unit and a first switch sub-unit, which can be a protection switch to protect the energy storage unit in abnormal circumstances.

[0332] In Examples 1 to 7 above, both the energy storage module 110 and the charging module 120 are connected to the DC bus, meaning the charging device 100 adopts a DC bus design. When multiple energy storage modules 110 and charging modules 120 are configured, the multiple charging devices 100 share a common DC bus. When the charging device 100 adopts a DC bus design, if the maximum charging output power of the charging device 100 is greater than or equal to 350 kW, the maximum output power of the battery sub-unit is greater than or equal to 350 kW, the rated power of the battery sub-unit is greater than or equal to 350 kW, the rated energy of the battery sub-unit is greater than or equal to 58 kW, the maximum discharge rate of the battery sub-unit is greater than or equal to 4C, the maximum output power of the first power conversion sub-unit is greater than or equal to 350 kW, and the rated power of the first power conversion sub-unit is greater than or equal to 310 kW. The maximum output power of the input module 130 is less than or equal to 150 kW, and the ratio of the maximum output power of the input module 130 to the maximum output power of the first power conversion sub-unit is not greater than 1:4.

[0333] Example 8, see reference 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 sub-unit, and the selection unit 111 includes three second switch sub-units K1, K2, and K3. The charging module 120 includes a fifth power conversion sub-unit 124 and a charging gun 122. The fifth power conversion sub-unit 124 has a high-voltage positive input terminal and a high-voltage negative input terminal, as well as a high-voltage positive output terminal and a high-voltage negative output terminal. The fifth power conversion sub-unit 124 can be a bipolar bidirectional DC-DC sub-unit. The input module 130 includes three tenth power conversion sub-units, which can be bidirectional single-phase AC-DC sub-units. The second external power supply 220 includes a second transformer connected to the AC power grid.

[0334] When charging the energy storage module 110, the second transformer converts the second AC power supplied by the AC grid into first AC power, which is then converted into DC power by the bidirectional single-phase AC-CDC sub-units to charge the corresponding battery sub-units. Each bidirectional single-phase AC-CDC sub-unit is connected to one phase AC bus; for example, the first bidirectional single-phase AC-CDC sub-unit is connected to phase A, the second bidirectional single-phase AC-CDC sub-unit is connected to phase B, and the third bidirectional single-phase AC-CDC sub-unit is connected to phase C. It should be noted that, under the action of the bidirectional single-phase AC-CDC sub-units, when the electrical energy in the energy storage module 110 is fed to the AC grid, the three bidirectional single-phase AC-CDC sub-units can cooperate to generate three-phase AC power with a 120° phase difference, thus enabling the output of three-phase AC power through the three energy storage units.

[0335] When charging the device to be charged, the energy storage unit provides a second DC power based on the electrical energy of the battery sub-unit. The energy storage module 110 selectively outputs the second DC power through the selection unit 111 to obtain a first DC power. This first DC power is converted into a fourth DC power by the high-power bipolar bidirectional DC-DC sub-unit and then used to charge the device to be charged through the charging gun 122 to achieve high-power charging, thereby realizing fast charging / supercharging of the device to be charged. In some examples, the second switch sub-units K1, K2, and K3 can be closed sequentially and individually in a time-sharing manner to keep the electrical charge in the three energy storage units consistent.

[0336] Understandably, with the help 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 AC grid, thereby realizing the free switching of electrical energy between the device to be charged, the energy storage module 110 and the AC grid.

[0337] Example 9, see reference Figure 22 This example is compared to Figure 21 The difference in the example shown is that the sixth power conversion subunit 125 only has a high-voltage positive input terminal and a high-voltage positive output terminal, and the high-voltage negative input terminal of the charging gun 122 is directly connected to the second negative power supply terminal of the energy storage module 110. That is, the negative terminal of the charging gun 122 and the energy storage module 110 are shared. The sixth power conversion subunit 125 can be a unipolar bidirectional DC-DC subunit.

[0338] In Examples 8 to 9 above, both the energy storage module 110 and the charging module 120 are connected to the AC bus, meaning the charging device 100 adopts an AC bus design. When multiple energy storage modules 110 and charging modules 120 are configured, the multiple charging devices 100 share the same AC bus.

[0339] In Examples 1 to 9 above, the charging device 100 can communicate with external devices, including but not limited to cloud services / monitoring platforms, via the wireless communication module 140 to achieve 4G / 5G communication. The cloud service / monitoring platform selects appropriate peak and valley periods based on the location of the charging device 100 and sends the data to the charging device 100, enabling peak shaving and valley filling. For example, during peak hours of the AC power grid, the AC power grid does not charge the energy storage module 110, while during off-peak hours, the AC power grid slowly charges the energy storage module 110.

[0340] It should be noted that Examples 1 to 9 above are merely illustrative examples. Based on the inventive concept of this application, any reasonable arrangement of the aforementioned architecture should be within the scope of protection of this application.

[0341] To further illustrate the implementation of the charging module rated charging output power greater than or equal to 290 kW in this application, the following details the battery sub-unit.

[0342] In this application, each energy storage unit may include a battery sub-cell, which may include one or more individual battery cells. Each individual battery cell may include an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The positive electrode includes a positive current collector and a positive electrode film layer disposed on at least one side of the positive current collector, the positive electrode film layer including a positive active material. The negative electrode includes a negative current collector and a negative electrode film layer disposed on at least one side of the negative current collector, the negative electrode film layer including a negative active material. Optionally, the individual battery cell also includes a housing, within which the electrode assembly and electrolyte are housed. The negative electrode film layer includes at least one film layer, which may be a single film layer or at least two film layers. Optionally, the negative electrode film layer includes at least two film layers. Similarly, the positive electrode film layer may be a single film layer or at least two film layers. During the charging and discharging process of a single battery cell, active ions such as lithium ions are inserted and extracted back and forth between the positive and negative electrode plates, and the electrolyte plays the role of conducting active ions between the positive and negative electrode plates.

[0343] The following details the electrolyte, positive electrode, negative electrode, and separator:

[0344] Electrolyte

[0345] In some embodiments, the electrolyte comprises an electrolyte salt, which includes lithium hexafluorophosphate, and the concentration of lithium hexafluorophosphate is in the range of 0.5 mol / L to 1.0 mol / L.

[0346] By setting the electrolyte to include lithium hexafluorophosphate of the above concentration, the battery sub-cell has a high ionic conductivity, thereby improving the charging rate of the charging device. It also gives the battery sub-cell high interface stability and high thermal stability. Lithium hexafluorophosphate has a small impact on the severity of thermal runaway, so that the battery sub-cell has a suitable degree of thermal runaway severity and a low risk of thermal diffusion, which makes the charging device highly reliable when the power output is above 350kW.

[0347] In some embodiments, the electrolyte further includes an organic solvent, including carbonate solvents.

[0348] Optionally, the carbonate solvent includes one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate. More preferably, the carbonate solvent includes one or more of ethylene carbonate, dimethyl carbonate, and methyl ethyl carbonate.

[0349] Further optionally, the carbonate solvent has a mass content of 10% to 70% in the organic solvent, and may be selected as one of 30% to 50%, 10% to 30%, or 30% to 70%.

[0350] For example, the mass content of the carbonate solvent in the organic solvent is 10%, 20%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 40%, 45%, 48%, 50%, 55%, 60%, 65%, 70%, or any combination of 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 beneficial for lithium ion migration.

[0351] For example, the carbonate solvent includes one or more of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate, and the mass content of the carbonate solvent is 30% to 50%.

[0352] Adding carbonate solvents to the electrolyte can improve various performance characteristics of battery sub-cells, such as charge / discharge efficiency, cycle performance, low-temperature performance, and high voltage stability, thereby enhancing battery discharge stability during high-power output.

[0353] In some embodiments, the electrolyte comprises an electrolyte salt, which includes lithium hexafluorophosphate, and the concentration of lithium hexafluorophosphate is in the range of 0.5 mol / L to 1.0 mol / L.

[0354] For example, 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 any combination of two of the above values.

[0355] For example, the proportion of lithium hexafluorophosphate can be, but is not limited to, 10%-25% based on the total mass of the electrolyte.

[0356] By setting the electrolyte to include lithium hexafluorophosphate of the above concentration, the battery sub-cell has a high ionic conductivity, thereby improving the charging rate of the charging device 100. It also gives the battery sub-cell high interface stability and high thermal stability. Lithium hexafluorophosphate has a small impact on the severity of thermal runaway, so that the battery sub-cell has a suitable degree of thermal runaway severity and a low risk of thermal diffusion, which makes the charging device highly reliable when the power output is above 350kW.

[0357] In some embodiments, the electrolyte salt further includes a fluorosulfonamide salt, the concentration of which is in the range of 0.2 mol / L to 0.5 mol / L.

[0358] Fluorosulfonyl imide salts may include one or more of lithium bisfluorosulfonyl imide (LiFSI) and lithium bistrifluoromethanesulfonate imide (LiTFSI).

[0359] Optionally, the lithium salt includes lithium bis(fluorosulfonyl)imide (LiFSI) and lithium hexafluorophosphate (LiPF6), wherein the molar concentration of lithium bis(fluorosulfonyl)imide (LiFSI) is from 0.2 mol / L to 0.5 mol / L, and the molar concentration of lithium hexafluorophosphate (LiPF6) is from 0.5 mol / L to 1.0 mol / L.

[0360] For example, the molar concentration of lithium bis(fluorosulfonyl)imide (LiFSI) is 0.4 mol / L to 0.5 mol / L, and the molar concentration of lithium hexafluorophosphate (LiPF6) is... 66 The molar concentration is 0.7 mol / L.

[0361] For example, the molar concentration of lithium bis(fluorosulfonyl)imide (LiFSI) is 0.5 mol / L, and the molar concentration of lithium hexafluorophosphate (LiPF6) is 0.5 mol / L.

[0362] For example, the molar concentration of lithium bis(fluorosulfonyl)imide (LiFSI) is 0.2 mol / L, and the molar concentration of lithium hexafluorophosphate (LiPF6) is 0.8 mol / L.

[0363] Optionally, the molar ratio of lithium bis(fluorosulfonyl)imide to lithium hexafluorophosphate (LiPF6) is from 0.2 to 1.0, and optionally from 0.2 to 0.5. Exemplarily, the molar ratio of lithium bis(fluorosulfonyl)imide to lithium hexafluorophosphate (LiPF6) is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, or a range of any two of the above values.

[0364] In the embodiments of this application, the types and contents of inorganic components / lithium salt concentrations in the electrolyte are well-known in the art and can be detected using well-known equipment and methods. For example, the concentrations of inorganic components / lithium salts in the electrolyte can be qualitatively or quantitatively analyzed by ion chromatography using the standard JY / T020-1996 "General Rules for Ion Chromatography Analysis". In the embodiments of this application, freshly prepared electrolyte can be used as a sample, the free electrolyte of a fresh battery can be used as a sample, or a battery that has been completely discharged (discharged to the lower limit cutoff voltage so that the battery's state of charge is approximately 0% SOC) can be disassembled in reverse, and the free electrolyte obtained from the battery can be used as a sample for detection by ion chromatography analysis.

[0365] In the embodiments of this application, the types and contents of organic components in the electrolyte are defined in the art and can be detected using equipment and methods known in the art. For example, the organic components in the electrolyte can be qualitatively and quantitatively analyzed by gas chromatography using GB / T9722-2006 "General Rules for Gas Chromatography of Chemical Reagents". In the embodiments of this application, freshly prepared electrolyte can be used as a sample, the free electrolyte of a fresh battery can be used as a sample, or a battery that has been completely discharged (discharged to the lower limit cutoff voltage so that the battery's state of charge is approximately 0% SOC) can be disassembled in reverse, and the free electrolyte obtained from the battery can be used as a sample for detection using ion chromatography.

[0366] In the embodiments of this application, after quantitative and qualitative detection of each component in the electrolyte, each component is classified. Chain carboxylic acid ester solvents and carbonate solvents (such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate) are taken as components of organic solvents. The mass content of each component is calculated with the mass of organic solvents as 100%.

[0367] Carbonate additives (such as vinylene carbonate and fluoroethylene carbonate), sulfur-containing additives, and lithium salt additives are used as additives in the electrolyte. The mass content of each component is calculated based on the mass of the electrolyte as 100%.

[0368] Because fluorosulfonyl imide salts have low viscosity and high ionic conductivity, electrolytes containing the above-mentioned concentrations of fluorosulfonyl imide salts are beneficial to improving the charging rate of battery sub-cells, thereby improving the charging rate of the charging device.

[0369] In some embodiments, the organic solvent includes a chain carboxylic acid ester solvent, and the mass content A of the chain carboxylic acid ester solvent satisfies: 5% ≤ A ≤ 75% based on the total mass of the solvent.

[0370] Among them, chain carboxylic acid ester solvents include compounds with the following structures:

[0371]

[0372] Wherein, R1 includes at least one of hydrogen atom, C1-C5 alkyl or C1-C5 haloalkyl, and R2 includes C1-C5 alkyl and / or C1-C5 haloalkyl.

[0373] The chain carboxylic acid ester solvent has a mass content of 5% or more and 75% or less relative to the organic solvent, optionally 10% or more and 75% or less, optionally 30% to 70%, or optionally 50% to 70%. For example, the mass content of the chain carboxylic acid ester solvent is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or a range of any two of the above values.

[0374] When the mass content of chain carboxylic acid ester solvents is within the above range, the viscosity of the electrolyte system is relatively low, which is conducive to the migration of lithium ions.

[0375] The aforementioned chain-like carboxylic acid ester solvents have high conductivity, which is beneficial for improving the fast charging capability of individual battery cells.

[0376] Optionally, R1 includes a hydrogen atom, a halogen atom, a C1 to C3 alkyl group, or a C1 to C3 haloalkyl group. Further optionally, R1 includes a hydrogen atom, a halogen atom, a C1 to C2 alkyl group, or a C1 to C2 haloalkyl group.

[0377] Optionally, R2 comprises a C1 to C3 alkyl group or a C1 to C3 haloalkyl group. More optionally, R2 comprises a C1 to C2 alkyl group or a C1 to C2 haloalkyl group.

[0378] In the above embodiments, the halogen atom includes one or more of fluorine, chlorine, bromine and iodine atoms, and optionally, the halogen atom includes fluorine atom.

[0379] In the above embodiments, the halogenated alkyl group includes one or more of fluoroalkyl, chloroalkyl, bromoalkyl and iodoalkyl groups, and optionally, the halogenated alkyl group includes fluoroalkyl.

[0380] For example, the chain carboxylic acid ester solvent includes one or more compounds of formula I-1 to formula I-8.

[0381]

[0382] In this technical solution, the solvent includes carboxylic acid ester solvents, so that the electrolyte can have higher ionic conductivity and relatively low viscosity, which is beneficial to further improve the fast charging performance of the charging device, such as fast charging performance and / or supercharging performance.

[0383] In some embodiments, the conductivity of the electrolyte at room temperature is from 13 mS / cm to 20 mS / cm, optionally from 15 mS / cm to 20 mS / cm. Exemplarily, the conductivity of the electrolyte at room temperature is 13 mS / cm, 13.5 mS / cm, 14 mS / cm, 14.5 mS / cm, 15 mS / cm, 15.5 mS / cm, 16 mS / cm, 16.5 mS / cm, 17 mS / cm, 17.5 mS / cm, 18 mS / cm, 18.5 mS / cm, 19 mS / cm, 19.5 mS / cm, 20 mS / cm, or any range of two of the above values.

[0384] When the conductivity of the electrolyte at room temperature, such as 25°C, is within the above range, the migration rate of lithium ions in the electrolyte is relatively high, which can further reduce the internal resistance of the individual cell, thereby reducing heat generation and improving the fast charging performance of the individual cell.

[0385] In the embodiments of this application, the conductivity of the electrolyte at room temperature, such as 25°C, is the ionic conductivity, which can be detected using equipment and methods known in the art, such as by referring to industry standard HG-T 4067-2015.

[0386] In some embodiments, the viscosity of the electrolyte at room temperature is between 2.3 mPa·s and 3.5 mPa·s. Exemplarily, the viscosity of the electrolyte is 2.3 mPa·s, 2.4 mPa·s, 2.5 mPa·s, 2.6 mPa·s, 2.7 mPa·s, 2.8 mPa·s, 2.9 mPa·s, 3.0 mPa·s, 3.1 mPa·s, 3.2 mPa·s, 3.3 mPa·s, 3.4 mPa·s, 3.5 mPa·s, or a range consisting of any two of the above values.

[0387] When the viscosity of the electrolyte at room temperature, such as 25°C, is within the above range, the migration rate of lithium ions in the electrolyte is relatively high, which can further reduce the internal resistance of the individual cell, thereby reducing heat generation and improving the fast charging performance of the individual cell.

[0388] In the embodiments of this application, the viscosity of the electrolyte has a meaning known in the art and can be detected using equipment and methods known in the art, such as in accordance with GB / T10247-2008.

[0389] In some embodiments, the density of the electrolyte at room temperature, such as 25°C, is between 1.05 g / mL and 1.35 g / mL. Exemplarily, the density of the electrolyte is 1.05 g / mL, 1.10 g / mL, 1.15 g / mL, 1.2 g / mL, 1.25 g / mL, 1.3 g / mL, 1.35 g / mL, or a range consisting of any two of the above values.

[0390] When the electrolyte density is within the above range, the migration rate of lithium ions in the electrolyte is relatively high, which can further reduce the internal resistance of the individual cell, thereby reducing heat generation and improving the fast charging performance of the individual cell.

[0391] In the embodiments of this application, the density of the electrolyte has a meaning known in the art and can be detected using equipment and methods known in the art, such as referring to GB / T 2013-2010 for testing.

[0392] Electrolytes consist of organic solvents and electrolyte salts. The types of organic solvents and electrolyte salts are not specifically limited and can be selected according to actual needs.

[0393] In some embodiments, the electrolyte may further include additives, which may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, additives that improve battery low-temperature power performance, etc.

[0394] In some embodiments, the additive comprises one or more of carbonate additives, sulfur-containing additives, and lithium salt additives, optionally at least two. These additives can improve the interfacial film performance on the positive and / or negative electrode sides, which is beneficial for improving the fast-charging performance of a single battery cell and enhancing cycle performance.

[0395] In some embodiments, the additive has a mass content of 1% to 10% in the electrolyte, optionally 2% to 8%, and more preferably 3.5% to 8%. Exemplarily, the additive has a mass content of 1%, 2%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any range of two of the above values.

[0396] The additives mentioned above can effectively improve the interfacial film performance on the positive and / or negative electrode sides, which is beneficial to improving the fast charging performance of individual cells and improving cycle performance.

[0397] For example, carbonate additives include one or more of vinylene carbonate (VC) and fluoroethylene carbonate (FEC).

[0398] For example, sulfur-containing additives include one or more of vinyl sulfate DTD, vinyl disulfide 2-DTD, butene sulfite BS, 1,3-propanesulfonate lactone PS, vinyl sulfite ES, and methylene disulfonate MMDS.

[0399] Optionally, the lithium salt additive includes one or more of lithium difluorophosphate (LiPO2F2), lithium difluorooxalate borate (LiDFOB), lithium tetrafluoroborate (LiBF4), and lithium dioxalate borate (LiBOB).

[0400] Optionally, the mass content of vinylene carbonate (VC) in the electrolyte is 0.5% to 9%, and optionally 2% to 6%.

[0401] Optionally, the mass content of fluoroethylene carbonate (FEC) in the electrolyte is 0.1% to 4%, and optionally 0.5% to 3%.

[0402] Optionally, the mass content of vinylene carbonate (VC) in the electrolyte is 0.5% to 9%, and the mass content of fluoroethylene carbonate (FEC) in the electrolyte is 0.1% to 4%.

[0403] Further optionally, the mass content of vinylene carbonate (VC) in the electrolyte is 2% to 6%, and the mass content of fluoroethylene carbonate (FEC) in the electrolyte is 0.5% to 3%.

[0404] In some embodiments, a single battery cell satisfies: 2.45 g / Ah ≤ d / A ≤ 3.5 g / Ah, optionally 2.45 g / Ah ≤ d / A ≤ 3.3 g / Ah, where d represents the mass of electrolyte in the single battery cell in grams (g), and A represents the rated capacity of the single battery cell in Ah. Exemplarily, d / A can be 3.5 g / Ah, 3.3 g / Ah, 3.2 g / Ah, 3.0 g / Ah, 2.8 g / Ah, 2.5 g / Ah, 2.45 g / Ah, or a range of any two of the above values.

[0405] d / A reflects the electrolyte's liquid retention capacity. When d / A is within the above range, the electrolyte can effectively wet the positive and negative electrode plates and improve the migration rate of lithium ions in the liquid phase, which is beneficial to improving the fast charging capability of a single cell.

[0406] In the embodiments of this application, the d / A of a single cell can be understood as the liquid retention coefficient, which can be tested using equipment and methods known in the art. For example, it can be described according to GB / T31486-2015 "Electrical Performance Requirements and Test Methods for Power Batteries for Electric Vehicles", taking a battery charging upper limit voltage of 3.65V and a battery discharge cut-off voltage of 2.0V as an example.

[0407] At 25℃, a single battery cell is charged to 3.65V at 0.33C, then charged at a constant voltage to 0.05C, and then discharged at a constant current of 0.33C to 2.0V. The discharged capacity A is used as the denominator. The weight of the single battery cell is M0. Then, the positive electrode, negative electrode, separator, and electrolyte are disassembled, with the free electrolyte stored in a bag. All the above solid components are placed in a 60℃ oven and baked for more than 4 hours (including but not limited to the positive electrode, negative electrode, separator, and other mechanical parts of the disassembled single battery cell that contribute to M0). Then, all components of the single battery cell are weighed again, M1, with the weight difference between M0 and M1 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.

[0408] [Negative electrode plate]

[0409] In some embodiments, the resistance value of the negative electrode can be, but is not limited to, within the range of 0.001Ω-0.01Ω.

[0410] The resistance can be selected from 0.001Ω to 0.005Ω. For example, the resistance of the negative electrode is 0.001Ω, 0.002Ω, 0.003Ω, 0.004Ω, 0.005Ω, 0.006Ω, 0.007Ω, 0.008Ω, 0.009Ω, 0.01Ω, or any combination of two of the above values.

[0411] In other examples, the resistance of the negative electrode can be in the range of 1mΩ-50mΩ.

[0412] Thus, when the resistance of the negative electrode is within the above range, it helps to reduce the internal resistance of the individual cell, improve the conductivity of the battery sub-cell, and thus increase the charging rate of the battery sub-cell, which is beneficial to improving the fast charging performance of the battery device.

[0413] In the embodiments of this application, the resistance of the negative electrode is a term known in the art and can be detected using equipment and methods known in the art, such as the resistance testing method for the positive electrode described above.

[0414] In some embodiments, the negative electrode active material comprises a carbon-based material, which includes at least one of natural graphite and artificial graphite. Alternatively, the carbon-based material may also include natural graphite. Specifically, the carbon-based material may include graphite particles, or the carbon-based material may include both graphite particles and natural graphite.

[0415] Optionally, the carbon-based material is graphite particles. Depending on the mass of the graphite particles, the mass percentage of natural graphite can be greater than that of synthetic graphite.

[0416] The carbon-based material uses at least one of natural graphite and artificial graphite as the negative electrode active material layer. Both have good conductivity and high theoretical specific capacity. Natural graphite has high crystallinity and a regular layered structure, which is conducive to the rapid insertion and extraction of lithium ions, thereby improving the battery charging and discharging efficiency. Artificial graphite can be precisely adjusted in terms of its microstructure and performance by controlling the production process, which can enhance the cycle stability of individual cells and extend the life of individual cells. Therefore, in high-power charging scenarios, it can extend the cycle life and charging stability of the charging device by 100%.

[0417] In some embodiments, the volume average particle size Dv50 of the negative electrode film can be, but is not limited to, in the range of 8.2 μm-13.5 μm.

[0418] When a single-layer negative electrode film is used, the negative electrode active material in the negative electrode film includes a carbon-based material, and optionally also includes a silicon-based material. When a single-layer film is used, the volume average particle size Dv50 of the negative electrode active material can be, but is not limited to, 8.2 μm to 13.5 μm. Exemplarily, the volume average particle size Dv50 of the negative electrode active material is 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm, or a range consisting of any two of the above values. In other embodiments, the volume average particle size Dv50 of the negative electrode film can be between 8.2 μm and 18.5 μm, for example, it can be 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm, 14 μm, 15 μm, 16.2 μm, 18 μm, 18.5 μm or any range of two of the above values.

[0419] When the negative electrode film layer comprises at least two film layers, the negative electrode active material in the negative electrode film layer includes a carbon-based material, and optionally also includes a silicon-based material. The silicon-based material may be located in one of the at least two film layers, or in at least two of the at least two film layers. The negative electrode film layer may include two film layers, three film layers, four film layers, or even more film layers.

[0420] The volume average particle size (Dv50) of the negative electrode film ranges from 8.2 μm to 13.5 μm, a range that balances specific surface area and compaction density. Smaller particle size provides a larger specific surface area, increasing the reaction sites for lithium ions and improving the charge / discharge rate performance of the individual cell; while an appropriate particle size provides a higher compaction density, reducing voids between active materials and increasing the energy density of the individual cell. This achieves a good balance between rate performance and energy density in the individual cell, meeting the charging requirements of the charging device 100 at different charging rates.

[0421] In some embodiments, the negative electrode film layer includes a first negative electrode active material layer and a second negative electrode active material layer stacked together. The first negative electrode active material layer is located on the side close to the negative electrode current collector. The volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer is 9.5 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.

[0422] When the volume average particle size Dv50 of the negative electrode active material in both the first and second negative electrode active material layers is within the aforementioned range, it can shorten the solid-phase transport path of lithium ions, improving fast charging performance. Furthermore, the materials are less prone to agglomeration during preparation, thus enhancing material stability. The combination of the negative electrode active materials in the second and first negative electrode active material layers within the aforementioned volume average particle size range facilitates the creation of a gradient porosity difference between the two layers, reducing lithium ion transport tortuosity and improving the fast charging performance of the battery cell.

[0423] In some embodiments, the negative electrode film layer includes a first negative electrode film layer and a second negative electrode film layer. The first negative electrode film layer is disposed on the surface of the negative electrode current collector. The carbon-based material in the first negative electrode film layer includes graphite particles. The second negative electrode film layer is connected to the side of the first negative electrode film layer away from the negative electrode current collector. The carbon-based material in the second negative electrode film layer also includes graphite particles. The graphite particles in the first negative electrode film layer and the graphite particles in the second negative electrode film layer may be the same or different.

[0424] The interface between the first negative electrode film and the second negative electrode film can be regular or irregular, and can optionally be irregular.

[0425] Optionally, the carbon-based material in the first negative electrode film layer may also include natural graphite.

[0426] The negative electrode film layer comprises at least two layers, and layered coating is beneficial for improving the fast charging performance of a single battery cell. In particular, when there are differences between the first and second negative electrode film layers, it is possible to create porosity differences in the negative electrode film layers, reduce the tortuosity of lithium-ion transport, and improve the fast charging performance of a single battery cell.

[0427] 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. More preferably, the volume average particle size Dv50 of the negative electrode active material in the first negative electrode film layer is greater than the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film layer, which is beneficial for increasing 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.

[0428] The difference in particle size between the first and second negative electrode layers can improve the fast charging performance of a single cell. Specifically, during fast charging, the overpotential of the second negative electrode layer is usually higher, and the bottleneck of fast charging is mainly in the second negative electrode layer. However, in the embodiments of this application, the particle size of the second negative electrode layer is relatively small, which can shorten the solid-phase transport path of lithium ions, improve fast charging performance, and improve the problem of lithium deposition on the surface of the negative electrode sheet.

[0429] Optionally, the negative electrode active material in the first negative electrode film layer is particulate, and its volume average particle size Dv50 is 9.5 μm to 18.5 μm, optionally 9.5 μm to 14.6 μm. Exemplarily, the volume average particle size of the negative electrode active material in the first negative electrode film layer is 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 14.6 μm, 15 μm, 15.5 μm, 16 μm, 16.5 μm, 17 μm, 17.5 μm, 18 μm, 18.5 μm, or a range consisting of any two of the above values. When the first negative electrode film layer includes graphite particles, the volume average particle size Dv50 of the graphite particles in the first negative electrode film layer is 9.5 μm to 18.5 μm, and can be selected as 9.5 μm to 14.6 μm.

[0430] When the volume average particle size Dv50 of the negative electrode active material in the first negative electrode film layer is within the above range, it can shorten the solid-phase transport path of lithium ions and improve fast charging performance. On the other hand, the material is less prone to agglomeration during the preparation process, which can improve the stability of the material.

[0431] Optionally, the negative electrode active material in the second negative electrode film layer is particulate, and its volume average particle size Dv50 is 7.8 μm to 14.3 μm, optionally 7.8 μm to 11.3 μm. For example, the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film layer is 7.8 μm, 8.0 μm, 8.2 μm, 8.5 μm, 8.8 μm, 9 μm, 9.2 μm, 9.5 μm, 9.8 μm, 10 μm, 10.2 μm, 10.5 μm, 10.8 μm, 11 μm, 11.3 μm, 11.2 μm, 11.5 μm, 11.8 μm, 12 μm, 12.2 μm, 12.5 μm, 12.8 μm, 13 μm, 13.2 μm, 13.5 μm, 13.8 μm, 14 μm, 14.1 μm, 14.3 μm, or a range consisting of any two of the above values. When the second negative electrode film layer includes graphite particles, the volume average particle size Dv50 of the graphite particles in the second negative electrode film layer is 7.8 μm to 14.3 μm, and can be selected as 7.8 μm to 11.3 μm.

[0432] When the volume average particle size Dv50 of the negative electrode active material in the second negative electrode film is within the above-mentioned range, it can shorten the solid-phase transport path of lithium ions and improve fast charging performance. On the other hand, the material is less prone to agglomeration during the preparation process, which can improve the stability of the material. Furthermore, the combination of the negative electrode active material in the second negative electrode film within the above-mentioned volume average particle size range with the negative electrode active material in the first negative electrode film is conducive to building a gradient porosity difference between the second negative electrode film and the first negative electrode film, reducing the tortuosity of lithium ion transport, and improving the fast charging performance of the single cell.

[0433] In the embodiments of this application, the volume average particle size Dv50 of the negative electrode active material has a meaning known in the art and can be detected using equipment and methods known in the art, such as the volume average particle size Dv50 test method for positive electrode active materials described above.

[0434] 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. Tap density reflects the packing 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 that in the first negative electrode film layer, the second negative electrode film layer is more densely packed, thus increasing the energy density of the individual battery cell. Conversely, the first negative electrode film layer is relatively sparsely packed with more pores, which improves the fast-charging performance of the individual battery cell. When the negative electrode active material includes graphite particles, the tap density of the graphite particles in the first negative electrode film layer is less than or equal to that in the second negative electrode film layer.

[0435] Optionally, the tap density of the carbon-based material in the first negative electrode film layer is 0.82 g / cm³. 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.

[0436] 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.

[0437] In the embodiments of this application, the tap density of the material has a meaning known in the art and can be determined using instruments and methods known in the art. For example, it can be determined using a powder tap density tester according to GB / T5162-2006. The testing instrument can be the Dandong Baite BT-301.

[0438] Optionally, the thickness ratio of the second negative electrode film to the first negative electrode film is 3:7 to 7:3, and optionally 4:6 to 6:4. For example, the thickness ratio of the second negative electrode film to the first negative electrode film is 3:7, 4:6, 5:5, 6:4, 7:3, or any range of two of the above values. By adjusting the thickness ratio of the first and second negative electrode films, the gradient porosity difference between the upper and lower layers can be further increased, reducing the tortuosity of lithium-ion transport and improving the fast charging capability of a single battery cell.

[0439] In some embodiments, when a single battery cell is 100% charged, the compaction density of the negative electrode film is 1.15 g / cm³. 3 -1.36g / cm 3 .

[0440] 1.25g / cm³ is optional. 3 Up to 1.36 g / cm 3 For example, the compaction density of the negative electrode film layer in a single battery cell at 100% charge is 1.15 g / cm³. 3 1.18 g / cm 3 1.20g / cm 3 1.22g / cm 3 1.25g / cm 3 1.28g / cm 3 1.3g / cm 3 1.32g / cm 3 1.35g / cm 3 1.36 g / cm 3 Or a range consisting of any two of the above values.

[0441] In the embodiments of this application, the compaction density of the negative electrode film layer of a single cell under 100% charge state has a well-known meaning in the art and can be detected using well-known equipment and methods in the art. The detection method is as described above for the compaction density test method of the positive electrode film layer.

[0442] When the compaction density of the negative electrode film is within the above range, it is beneficial to improve the energy density of the battery cell. Furthermore, since the negative electrode active material in the negative electrode film is packed more tightly, the contact resistance between particles is smaller, which can further reduce the resistance of the electrode sheet, thereby reducing heat generation.

[0443] In some embodiments, the compacted density of the negative electrode active material powder under a pressure of 20000N is 1.5 g / cm³. 3 Up to 1.85 g / cm 3 1.55g / cm³ is an optional value. 3 Up to 1.65 g / cm 3 For example, the compacted density of the negative electrode active material powder under a pressure of 20000N is 1.5 g / cm³. 3 1.55g / cm 3 1.6g / cm 3 1.65g / cm 3 1.7g / cm 3 1.75g / cm 3 1.8g / cm 3³ 1.85g / cm 3 Or a range consisting of any two of the above values.

[0444] When the powder compaction density of the negative electrode active material at 20000N is within the above range, it can improve the energy density of the single cell. Furthermore, since the negative electrode active material in the negative electrode film can be stacked more tightly, the contact resistance between particles is smaller, which can further reduce the resistance of the electrode sheet, thereby reducing heat generation.

[0445] In this application, the powder compaction density of the material has a meaning known in the art and can be tested using methods and equipment known in the art, according to the testing standard GB / T24533-2009. As an example, a certain amount of negative electrode active material is taken as a sample and added to a UTM7305 electronic pressure testing machine with a base area of ​​1.327 cm². 2² In the mold, the pressure is increased to 2000 kg (equivalent to 20000 N), held for 30 s, then depressurized and held for 10 s. The compaction density of the negative electrode active material under a force of 20000 N is then recorded and calculated.

[0446] In some embodiments, the specific charge capacity of the negative electrode active material at a 0.1C rate is between 350 mAh / g and 480 mAh / g. Exemplarily, the specific charge capacity of the negative electrode 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 consisting of any two of the above values.

[0447] When the charge capacity of the negative electrode active material at a 0.1C rate is within the above range, the energy density of the single cell is relatively high.

[0448] In the embodiments of this application, the charging capacity of the negative electrode active material at a rate of 0.1C is a well-known concept in the art and can be detected using well-known equipment and methods in the art. The detection method is as described above for the charging capacity test method of the positive electrode active material at a rate of 0.1C.

[0449] In some embodiments, the negative electrode active material layer includes a carbon-based material. Carbon-based materials exhibit high cycle stability, which can improve the cycle performance of a single battery cell. Optionally, the mass percentage of carbon-based material in the negative electrode active material can be greater than or equal to 80% and less than or equal to 100%.

[0450] The positive electrode active material of this application is mainly a lithium phosphate system with an olivine structure, and the negative electrode active material is mainly a carbon-based material system. When used together, the cycle performance of the single cell is relatively excellent.

[0451] Optionally, the carbon-based material includes graphite particles with a graphitization degree of 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 consisting of any two of the above values.

[0452] When the graphitization degree of graphite particles is within the above range, the graphite particles have excellent conductivity, which can reduce the heat generation of the negative electrode sheet, reduce the heat generation of the individual battery cell, and improve the fast charging performance of the individual battery cell.

[0453] In some embodiments, the graphite particles include artificial graphite and a carbon coating layer. The artificial graphite includes secondary particles, which in turn include multiple primary particles. The carbon coating layer coats the surface of the artificial graphite. The carbon in the carbon coating layer is primarily amorphous carbon, which refers to transitional carbon materials with a very low degree of graphitization and crystallization, exhibiting an approximately amorphous morphology (or lacking a fixed shape and periodic structural regularity). In this application, amorphous carbon refers to the product of carbonization treatment of an organic carbon source.

[0454] Artificial graphite includes secondary particles. There are more migration paths for lithium ions in artificial graphite, and the migration paths in primary particles are shorter, which can improve the migration rate of lithium ions. The carbon coating layer has more end faces and defects, which increases the number of sites where lithium ions can be inserted or extracted, resulting in better conductivity of the carbon coating layer. This can reduce the internal resistance of the negative electrode and reduce the heat generation of a single cell.

[0455] Optionally, the carbon coating content is 2% to 5% by mass, based on the mass of the graphite particles. For example, the carbon coating content is 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any range of two of the above values.

[0456] When the mass content of the carbon coating is within the above range, it can further reduce the internal resistance of the negative electrode and reduce the heat generation of the single cell.

[0457] In the embodiments of this application, the graphite particles can be prepared using methods known in the art, such as: providing artificial graphite and an organic carbon source, mixing the two, and then carbonizing them to form a carbon coating layer on at least a portion of the surface of the artificial graphite particles.

[0458] Optionally, the organic carbon source includes one or more of coal tar pitch, petroleum asphalt, phenolic resin, and coconut shell. More preferably, the organic carbon source includes petroleum asphalt. Optionally, the softening point of the coal tar pitch or petroleum asphalt is below 250°C.

[0459] Optionally, the carbonization temperature is between 700°C and 1800°C. Optionally, the carbonization temperature is between 1000°C and 1300°C. Within a suitable range, the carbonization temperature allows the organic carbon source to be carbonized, forming a coating layer containing amorphous carbon on at least a portion of the surface of the artificial graphite.

[0460] Optionally, the carbonization treatment time is 1 hour to 6 hours.

[0461] In some embodiments, the negative electrode active material may further include a silicon-based material. The introduction of a silicon-based material can improve the capacity of the negative electrode active material and increase the energy density of a single battery cell.

[0462] Optionally, based on the mass of the negative electrode active material, the mass content of silicon element in the silicon-based material is 0.3% to 10.0%, optionally 1% to 6%. For example, the mass content of silicon element in the silicon-based material is 0.3%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, 8%, 8.2%, 8.5%, 8.8%, 9%, 9.2%, 9.5%, 9.8%, 10%, or a range consisting of any two of the above values.

[0463] When the mass content of silicon in silicon-based materials is within the above range, it can increase the capacity of the negative electrode active material, thereby improving the energy density of the single cell.

[0464] Optionally, the silicon-based material may include at least one of elemental silicon, silicon oxide, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy.

[0465] In some embodiments, the negative electrode active material may include, in addition to the carbon-based material and optionally the silicon-based material described above, at least one of the tin-based material and lithium titanate. The tin-based material may include at least one of elemental tin, tin oxide, and tin alloy materials.

[0466] The qualitative and quantitative analysis of each substance or element in this application can be performed using suitable equipment and methods known to those skilled in the art. Relevant testing methods can be referenced from domestic and international testing standards and enterprise standards. Furthermore, those skilled in the art can adaptively modify certain testing steps / instrument parameters from the perspective of testing accuracy to obtain more accurate results. One testing method can be used for qualitative or quantitative analysis, or several testing methods can be used in combination for qualitative or quantitative determination.

[0467] For example, this application can combine the general rules of X-ray diffraction analysis in JIS / K0131-1996 to perform X-ray powder diffraction tests and qualitative analysis on negative electrode sheets or negative electrode active materials.

[0468] Artificial graphite and natural graphite can be distinguished by SEM cross-sectional images taken by scanning electron microscope (SEM). Natural graphite has gaps between its sheet-like structures in its SEM cross-section, while artificial graphite has a dense structure with no obvious gaps in its SEM cross-section. Alternatively, they can be distinguished by XRD patterns obtained by X-ray diffraction. Natural graphite has obvious 2H and 3R phases in its XRD pattern, while artificial graphite only has the 2H phase in its XRD pattern.

[0469] In some embodiments, the powder resistivity of the negative electrode active material is from 0.005 Ω•cm to 0.043 Ω•cm, optionally 0.04 Ω•cm. Exemplarily, the powder resistivity of the negative electrode active material can be 0.043 Ω•cm, 0.04 Ω•cm, 0.035 Ω•cm, 0.03 Ω•cm, 0.025 Ω•cm, 0.02 Ω•cm, 0.015 Ω•cm, 0.01 Ω•cm, 0.005 Ω•cm, or a range consisting of any two of the above values.

[0470] The powder resistivity of the negative electrode active material is relatively low, which results in relatively low resistance of the negative electrode sheet and less heat generation in a single cell.

[0471] In the embodiments of this application, the powder resistivity of the negative electrode active material has a well-known meaning in the art and can be detected using well-known equipment and methods in the art, such as the powder resistivity test method for the positive electrode active material described above.

[0472] In some embodiments, after 10 full-charge cycles during the Beginning of Life (BOL) test, the thickness of the first negative electrode film layer in a single battery cell is between 15 μm and 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 any combination of two of the above values. When the thickness of the first negative electrode film layer is within the above range, it can increase the gradient porosity difference between the first and second negative electrode film layers, reduce the tortuosity of lithium-ion transport, and improve the fast charging capability of the single battery cell.

[0473] In some embodiments, after 10 full-charge cycles during the Beginning of Life (BOL) test, the thickness of the second negative electrode film layer in a single battery cell is between 15 μm and 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 any combination of two of the above values. When the thickness of the second negative electrode film layer is within the above range, it can increase the gradient porosity difference between the first and second negative electrode film layers, reduce the tortuosity of lithium-ion transport, and improve the fast charging capability of the single battery cell.

[0474] In the embodiments of this application, for example, a battery charging upper limit voltage of 3.65V and a battery discharging cutoff voltage of 2.0V will be used for explanation.

[0475] The BOL full charge test procedure is as follows: At 25℃, charge the battery to 3.65V at a charging rate of 0.33C (the nominal capacity), then charge it to 0.05C at a constant voltage of 3.65V. Let it rest for 10 minutes, then discharge it to 2.0V at a discharging rate of 0.33C. Let it rest for 10 minutes. One charge-discharge cycle is completed. Perform 10 cycles, then charge the battery to 3.65V at a charging rate of 0.33C (the nominal capacity), and then charge it to 0.05C at a constant voltage of 3.65V. In the BOL fully charged state, disassemble the negative electrode sheet and use a tomographic scanning electron microscope to observe the cross-section of the thickness direction of the middle region of the negative electrode sheet. Distinguish the two regions according to the interface between the first negative electrode film layer and the second negative electrode film layer, and measure the thickness of each. For example, measure the thickness of the first negative electrode film layer at 10 locations and calculate the average value as the average thickness of the first negative electrode film layer. Measure the thickness of the second negative electrode film layer at 10 locations and calculate the average value as the average thickness of the second negative electrode film layer.

[0476] In some embodiments, after a single cell undergoes an end-of-life (EOL) full-charge test, the thickness of the first negative electrode film layer is between 15 μm and 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 any combination of two of the above values. When the thickness of the first negative electrode film layer is within the above range, it can increase the gradient porosity difference between the first and second negative electrode film layers, reduce the lithium-ion transport tortuosity, and improve the fast charging capability of the single cell.

[0477] In some embodiments, after a single cell undergoes an end-of-life (EOL) full-charge test, the thickness of the second negative electrode film is between 15 μm and 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 any combination of two of the above values. When the thickness of the second negative electrode film is within the above range, it can increase the gradient porosity difference between the first and second negative electrode films, reduce the lithium-ion transport tortuosity, and improve the fast-charging capability of the single cell.

[0478] In the embodiments of this application, for example, the upper limit voltage for battery charging is 3.65V and the cutoff voltage for battery discharging is 2.0V.

[0479] The EOL full charge test steps are as follows: At 60℃, charge the battery to 3.65V at a charging rate of 0.33C (the nominal capacity), then charge it to 0.05C at a constant voltage of 3.65V, let it stand for 10 minutes, then discharge it to 2.0V at a discharging rate of 0.33C, and let it stand for 10 minutes. One charge and discharge cycle is one cycle. The test continues until the battery capacity decreases to 80% of the nominal capacity. Then, charge at 25°C with a constant current of 0.33C to 3.65V, and then charge at a constant voltage of 0.05C to 3.65V, which is the EOL full charge state. In the EOL full charge state, disassemble the negative electrode plate and use a tomographic scanning electron microscope to observe the cross-section of the thickness direction of the middle region of the negative electrode plate. Distinguish the two regions according to the interface between the first negative electrode film layer and the second negative electrode film layer, and measure the thickness of each. For example, measure the thickness of the first negative electrode film layer at 10 locations and calculate the average value as the average thickness of the first negative electrode film layer. Measure the thickness of the second negative electrode film layer at 10 locations and calculate the average value as the average thickness of the second negative electrode film layer.

[0480] In some embodiments, when the negative electrode film layer is a single-layer film (as opposed to the double-layer film layer described above), the negative electrode film layer further includes a lithium-containing binder. Optionally, the mass content of the lithium-containing binder relative to the negative electrode film layer is 0.1% to 1%. Exemplarily, the mass content of the lithium-containing binder relative to 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 any combination of two of the above values. The lithium element in the lithium-containing binder can exist in ionic form, which can increase the number of freely moving lithium ions in the negative electrode film layer, shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, improve the lithium ion insertion / extraction rate, and improve the fast charging performance of the single cell. Optionally, the negative electrode film layer may further include a negative electrode binder, such as at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0481] Optionally, the lithium content in the lithium-containing binder is 3% to 10% by mass. For example, the lithium content in the lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any combination of two of the above values. The lithium content is calculated based on the mass of the lithium-containing binder. When the lithium content is within the above range, a relatively large number of freely moving lithium ions can be achieved in the negative electrode film layer, further shortening the distance that lithium ions diffuse to the surface of the negative electrode film layer, increasing the lithium ion insertion / extraction rate, and improving the fast charging performance of the single cell.

[0482] For example, lithium-containing binders include lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymers, which are derived from lithium acrylate monomers, acrylonitrile monomers, acrylamide monomers, and hydroxyethyl acrylate monomers, wherein the molar ratio of lithium acrylate monomers, acrylonitrile monomers, acrylamide monomers, and hydroxyethyl acrylate monomers is 30% to 50%: 15% to 45%: 5% to 20%: 20% to 35%. For example, the molar ratio of lithium acrylate monomers, acrylonitrile monomers, acrylamide monomers, and hydroxyethyl acrylate monomers is 35%: 30%: 15%: 20%, or 40%: 20%: 10%: 30%, or 45%: 15%: 20%: 20%, etc.

[0483] The lithium-containing binder of the above-mentioned material can provide a certain number of lithium ions to the negative electrode film layer, improve the fast charging performance of the single cell, and is not prone to swelling during charging and discharging, with a stable structure, which improves the cycle performance of the negative electrode film layer during fast charging and discharging.

[0484] In other embodiments, where the negative electrode film layer comprises at least two layers, the negative electrode film layer further includes a lithium-containing binder.

[0485] Optionally, the first negative electrode film layer further includes a first lithium-containing binder, and the second negative electrode film layer further includes a second lithium-containing binder, wherein the mass content of the first lithium-containing binder relative to the mass of the first negative electrode film layer is less than or equal to the mass content of the second lithium-containing binder relative to the mass of the second negative electrode film layer. More 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.

[0486] The second lithium-containing binder has a relatively high mass content in the second negative electrode film layer. The second lithium-containing binder provides a relatively larger number of freely moving lithium ions to the second negative electrode film layer, which can further improve the fast charging performance of the single cell.

[0487] Optionally, the mass content of the first lithium-containing binder relative to the first negative electrode film layer is 0.1% to 1%. For example, the mass content of the first lithium-containing binder relative to 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 any combination of two of the above values. The lithium element in the first lithium-containing binder can exist in ionic form, which can increase the number of freely moving lithium ions in the negative electrode film layer, shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, improve the lithium ion insertion / extraction rate, and improve the fast charging performance of the single cell.

[0488] Optionally, the lithium content in the first lithium-containing binder is 3% to 10% by mass, and optionally 3% to 8%. For example, the lithium content in the first lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any combination of two of the above values. When the lithium content is within the above range, a relatively large number of freely moving lithium ions can be achieved in the negative electrode film layer, further shortening the distance that lithium ions diffuse to the surface of the negative electrode film layer, increasing the lithium ion insertion / extraction rate, and improving the fast charging performance of the single cell.

[0489] For example, the first lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, which is derived from lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and hydroxyethyl acrylate monomer, wherein 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.

[0490] The lithium-containing binder of the above-mentioned material can provide a certain number of lithium ions to the negative electrode film layer, improve the fast charging performance of the single cell, and is not prone to swelling during charging and discharging, with a stable structure, which improves the cycle performance of the negative electrode film layer during fast charging and discharging.

[0491] Optionally, the mass content of the second lithium-containing binder relative to 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 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 any combination of two of the above values. The lithium element in the second lithium-containing binder can exist in ionic form, which can increase the number of freely moving lithium ions in the negative electrode film layer, shorten the distance for lithium ions to diffuse to the surface of the negative electrode film layer, improve the lithium ion insertion / extraction rate, and improve the fast charging performance of the single cell.

[0492] The first lithium-containing binder and the second lithium-containing binder can be made of the same material or different materials.

[0493] Optionally, the lithium content in the second lithium-containing binder is 3% to 10% by mass, and optionally 3% to 8%. For example, the lithium content in the second lithium-containing binder is 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any combination of two of the above values. When the lithium content is within the above range, a relatively large number of freely moving lithium ions can be achieved in the negative electrode film layer, further shortening the distance that lithium ions diffuse to the surface of the negative electrode film layer, increasing the lithium ion insertion / extraction rate, and improving the fast charging performance of the single cell.

[0494] For example, the second lithium-containing binder includes a lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, which is derived from lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer, and hydroxyethyl acrylate monomer, wherein 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.

[0495] The lithium-containing binder of the above-mentioned material can provide a certain number of lithium ions to the negative electrode film layer, improve the fast charging performance of the single cell, and is not prone to swelling during charging and discharging, with a stable structure, which improves the cycle performance of the negative electrode film layer during fast charging and discharging.

[0496] In some embodiments, the first negative electrode film layer further includes a negative electrode binder, and the second negative electrode film layer further includes a negative electrode binder. The negative electrode binder in the first negative electrode film layer and the negative electrode binder in the second negative electrode film layer each independently include at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0497] 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.

[0498] In some embodiments, the negative electrode film layer may optionally include a negative electrode conductive agent. This application does not impose any particular limitation on the type of negative electrode conductive agent. As an example, the negative electrode conductive agent may include at least one selected from superconducting 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.

[0499] In some embodiments, the negative electrode film layer may also optionally include 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.

[0500] In some embodiments, the negative electrode film layer may optionally include other additives. As examples, other additives may include thickeners, dispersants, etc., such as sodium carboxymethyl cellulose (CMC-Na), PTC thermistor materials, etc. In some embodiments, the mass content of other additives is ≤2% based on the total weight of the negative electrode film layer.

[0501] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. Examples of metal foils include at least one foil selected from copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. The composite current collector may include a polymeric material substrate and a metal material layer formed on at least one surface of the polymeric material substrate. As an example, the metal material layer may include at least one selected from copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymeric material substrate may include at least one selected from polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0502] In some embodiments, the ratio CB of the capacity of the negative electrode film per unit area to the capacity of the positive electrode film per unit area in a single cell is 1.05 to 1.30, and optionally 1.07 to 1.15. Exemplarily, the ratio CB of the capacity of the negative electrode film per unit area to the capacity of the positive electrode film per unit area in a single cell is 1.05, 1.07, 1.1, 1.12, 1.15, 1.18, 1.2, 1.22, 1.25, 1.28, 1.3, or a range of any two of the above values.

[0503] When the ratio CB of the capacity of the negative electrode film per unit area to the capacity of the positive electrode film per unit area in a single cell is within the above range, there are sufficient sites in the negative electrode film for lithium insertion, which can reduce the risk of lithium plating and facilitate fast charging.

[0504] In the embodiments of this application, the CB value has a well-known meaning in the art and can be detected using well-known equipment and methods in the art. For example, the capacity of the negative electrode film per unit area and the capacity of the positive electrode film per unit area can be calculated respectively, and the ratio between the two can be calculated to obtain the CB value.

[0505] Specifically, this explanation will be based on an example where the upper limit of battery charging voltage is 3.65V and the battery discharge cutoff voltage is 2.0V.

[0506] The capacity per unit area of ​​the positive electrode film refers to the actual lithium-depleting capacity of the positive electrode active material. The testing method is as follows: The battery is disassembled in a Braun glove box (PRS340 / 11-119-11), the positive electrode sheet is removed, and assembled into a CR2430 model semi-button battery with a positive electrode and lithium sheet. The positive electrode sheet area used is a mm². 2 The electrolyte used is 1 mol / L LiPF6. 66 The solution was prepared in an EC / EMC / DEC ratio of 3 / 5 / 2 (mass ratio). The assembled semi-coin cells were then left to stand for 3 hours. The test was conducted at 25°C. The cells were first charged at 0.1C in the voltage range of 2.0V to 3.65V to remove lithium, and then discharged at 0.05C to insert lithium to 2.0V. This cycle was repeated twice. The discharge coin capacity of the second cycle was recorded as YmAh. The actual battery design has a positive electrode length of bmm and a width of cmm. The number of surfaces of the positive electrode active material coated on the positive electrode current collector is d. Therefore, the capacity of the positive electrode film per unit area is Y / (a*b*c*d).

[0507] Specifically, the capacity per unit area of ​​the negative electrode film refers to the actual lithium intercalation capacity of the negative electrode active material. The testing method is as follows: The battery is disassembled in a PRS340 / 11-119-11 Braun glove box, the negative electrode sheet is removed, and it is assembled into a CR2430 model semi-button battery with a negative electrode and lithium sheet. The area of ​​the negative electrode sheet used is fmm². 2² The electrolyte used is 1 mol / L LiPF6. 66 The solution is prepared in an EC / EMC / DEC ratio of 3 / 5 / 2 (mass ratio). The assembled semi-coin cells are then left to stand for 3 hours. The test is conducted at 25°C. Lithium insertion is performed by discharging at 0.1C in the voltage range of 2V-0V, followed by lithium extraction by charging at 0.05C to 2V. This cycle is repeated twice. The discharge coin capacity of the second cycle is recorded as ZmAh. The actual battery design has a negative electrode length of hmm and a width of imm. The number of surfaces of the negative electrode active material coated on the negative electrode current collector is d. Therefore, the lithium insertion capacity of the negative electrode is Z / (f*h*i*d).

[0508] In some embodiments, the single-sided coating weight of the negative electrode film is 0.09 g / 1540.25 mm.2 -0.17g / 1540.25mm 2

[0509] Optionally, the single-sided coating weight of the negative electrode film is 110 mg / 1540.25 mm. 2 Up to 150mg / 1540.25mm 2 For example, the single-sided coating weight of the negative electrode film is 90 mg / 1540.25 mm. 2 92mg / 1540.25mm 2 95mg / 1540.25mm 2 96mg / 1540.25mm 2 100mg / 1540.25mm 2 102mg / 1540.25mm 2 104mg / 1540.25mm 2 105mg / 1540.25mm 2 108mg / 1540.25mm 2 110mg / 1540.25mm 2 112mg / 1540.25mm 2 114mg / 1540.25mm 2 115mg / 1540.25mm 2 116mg / 1540.25mm 2 118mg / 1540.25mm 2 120mg / 1540.25mm 2 122mg / 1540.25mm 2 125mg / 1540.25mm 2 128mg / 1540.25mm 2 130mg / 1540.25mm 2 132mg / 1540.25mm 2 135mg / 1540.25mm 2 137mg / 1540.25mm 2 140mg / 1540.25mm 2 142mg / 1540.25mm 2 145mg / 1540.25mm 2 148mg / 1540.25mm 2 150mg / 1540.25mm 2 152mg / 1540.25mm 2155mg / 1540.25mm 2 160mg / 1540.25mm 2 165mg / 1540.25mm 2 170mg / 1540.25mm 2 Or a range consisting of any two of the above values.

[0510] In the embodiments of this application, the single-sided coating weight of the negative electrode film layer has a meaning known in the art and can be detected using equipment and methods known in the art, such as the single-sided coating weight test method of the film layer described above.

[0511] When the single-sided coating weight of the negative electrode film is within the above range, the heat generation per unit area of ​​the negative electrode sheet will not be too large, and the energy density of the battery cell can be improved at the same time.

[0512] In some embodiments, the thickness of the negative electrode current collector is 4 μm to 6 μm. Exemplarily, the thickness of the negative electrode current collector is 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, or any combination of two of these values. In other examples, the thickness of the negative electrode current collector is 4 μm to 10 μm, or 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 any combination of two of these values. The negative electrode current collector can be copper.

[0513] When the thickness of the negative electrode current collector is within the above range, the current carrying capacity of the negative electrode current collector is relatively excellent, and it can enable the single cell to have a high energy density.

[0514] In the embodiments of this application, the thickness of the negative electrode current collector has a meaning known in the art and can be detected using equipment and methods known in the art. For example, the film layer on the surface of the negative electrode current collector can be washed away with a solvent, and the thickness of the negative electrode current collector can be measured with a micrometer.

[0515] The negative electrode film is typically formed by coating a negative electrode slurry onto a negative electrode current collector, followed by 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 until homogeneous. The solvent can be N-methylpyrrolidone (NMP) or deionized water, but is not limited to these.

[0516] The negative electrode sheet does not exclude other additional functional layers besides the negative electrode film layer. For example, in some embodiments, the negative electrode sheet of this application further includes a negative electrode conductive layer sandwiched between the negative electrode current collector and the negative electrode film layer and disposed on the surface of the negative electrode current collector. In other embodiments, the negative electrode sheet of this application further includes a protective layer covering the surface of the negative electrode film layer.

[0517] In some embodiments, the negative electrode sheet further includes a negative electrode conductive layer, which is located between the negative electrode film layer and the negative electrode current collector. The negative electrode conductive layer can further improve the conductivity of the negative electrode sheet and reduce the heat generation of the negative electrode sheet, thereby reducing the heat generation of a single battery cell.

[0518] In some embodiments, the thickness of the negative electrode conductive layer is from 0.5 μm to 2 μm. Exemplarily, the thickness of the negative electrode conductive layer can be 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.6 μm, 1.8 μm, 2 μm, or any range of two of the above values.

[0519] When the thickness of the negative electrode conductive layer is within the above range, the conductivity of the negative electrode sheet can be further improved, the heat generation of the negative electrode sheet can be reduced, thereby reducing the heat generation of the individual cell, and the energy density of the individual cell can also be improved.

[0520] In the embodiments of this application, the thickness of the negative electrode conductive layer has a meaning known in the art and can be detected using equipment and methods known in the art, such as the test method for the negative electrode conductive layer described above.

[0521] In some embodiments, the negative electrode conductive layer includes one or more of a negative electrode conductive agent and a negative electrode binder. The negative electrode conductive agent in the negative electrode conductive layer can improve the conductivity of the negative electrode conductive layer, thereby improving the conductivity of the negative electrode sheet and reducing the heat generation of a single cell. The negative electrode binder in the negative electrode conductive layer can improve the bonding performance between the negative electrode current collector and the negative electrode film layer, thereby improving the structural stability of the negative electrode sheet.

[0522] In some embodiments, the negative electrode conductive layer may optionally include other additives. As an example, other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC), PTC thermistor materials, etc.

[0523] 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 any combination of two of the above values.

[0524] For example, the negative electrode conductive agent includes one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0525] 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 any range of two of the above values.

[0526] For example, the negative electrode binder includes one or more of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based acrylic resin, polyvinyl alcohol, sodium alginate, and carboxymethyl chitosan.

[0527] [Positive electrode plate]

[0528] In some embodiments, the resistance of the positive electrode is in the range of 0.1Ω to 30Ω, and can be selected from 0.1Ω to 5Ω, and further selected from 0.1Ω to 1Ω. For example, the resistance of the positive electrode is 0.1Ω, 0.5Ω, 1Ω, 1.5Ω, 2Ω, 2.5Ω, 3Ω, 3.5Ω, 4Ω, 4.5Ω, 5Ω, 5.5Ω, 6Ω, 6.5Ω, 7Ω, 7.5Ω, 8Ω, 8.5Ω, 9Ω, 9.5Ω, 10Ω, 10.5Ω, 11Ω, 11.5Ω, 12Ω, 12.5Ω, 13Ω, 13.5Ω, 14Ω, 14.5Ω, 15Ω, 15.5Ω, 16Ω, 16.5Ω, 17Ω, 17.5Ω, 18Ω, 18.5Ω, 19Ω, 20Ω, 21Ω, 22Ω, 23Ω, 24Ω, 25Ω, 26Ω, 27Ω, 28Ω, 29Ω, 30Ω, or any range of two of the above values.

[0529] In other examples, the resistance of the positive electrode can be in the range of 0.01mΩ to 30Ω.

[0530] This improves the conductivity of the battery sub-cells, thereby enhancing the charging performance of the charging device.

[0531] In some embodiments, when a single battery cell is 100% charged, the compaction density of the positive electrode film can be, but is not limited to, 2.5 g / cm³. 3 -2.8g / cm 3 2.55g / cm³ is an optional value. 3 Up to 2.70 g / cm 3 For example, at 100% state of charge (SOC), the compaction density of the positive electrode film in a single battery cell is 2.2 g / cm³. 3 2.50g / cm 3 2.52g / cm 3 2.55g / cm 3 2.56 g / cm 3 2.57g / cm 3 2.58g / cm 3 2.60g / cm 3 2.62 g / cm 3 2.65g / cm 3 2.68g / cm 3 2.70 g / cm 3 2.72 g / cm3 2.75g / cm 3 2.78g / cm 3 2.80g / cm 3 Or a range consisting of any two of the above values.

[0532] When the compaction density of the positive electrode film is within the aforementioned range, it is beneficial to improve the energy density of a single battery cell. Furthermore, because the positive electrode active material in the positive electrode film is densely packed, the contact resistance between particles is low, which can further reduce the resistance of the electrode sheet, thereby reducing heat generation during fast charging. Therefore, by adjusting the compaction density of the positive electrode film to a reasonable range, a single battery cell can achieve both high energy density and high charging rate performance.

[0533] Optionally, the powder compaction density of the positive electrode active material at 30000N is 2.46 g / cm³. 3 Up to 2.8 g / cm 3 For example, the compacted density of the positive electrode active material at 30000 N is 2.46 g / cm³. 3 2.47 g / cm 3 2.48 g / cm 3 2.49 g / cm 3 2.5g / cm 3 2.51g / cm 3 2.55g / cm 3 2.58g / cm 3 2.60g / cm 3 2.65g / cm 3 2.68g / cm 3 2.70 g / cm 3 2.72 g / cm 3 2.75g / cm 3 2.78g / cm 3 2.80g / cm 3 Or a range consisting of any two of the above values.

[0534] When the powder compaction density of the positive electrode active material at 30000N is within the above range, it can improve the energy density of the single cell. Furthermore, since the positive electrode active material in the positive electrode film can be stacked more tightly, the contact resistance between particles is smaller, which can further reduce the resistance of the electrode sheet, thereby reducing heat generation.

[0535] In the embodiments of this application, the powder compaction density of the material has a meaning known in the art and can be tested using methods and equipment known in the art, according to the testing standard GB / T24533-2009. For example, a certain amount of positive electrode active material is taken as a sample and added to a UTM7305 electronic pressure testing machine with a bottom area of ​​1.327 cm². 2 In the mold, the pressure is increased to 3000 kg (equivalent to 30000 N), held for 30 seconds, then depressurized and held for 10 seconds. The compaction density of the positive electrode active material under a force of 30000 N is then recorded and calculated.

[0536] In some embodiments, the single-sided coating weight of the positive electrode film is 0.2 g / 1540.25 mm. 2 Up to 0.37g / 1540.25mm 2 The option is 240mg / 1540.25mm. 2 Up to 330mg / 1540.25mm 2 For example, the single-sided coating weight of the positive electrode film is 200 mg / 1540.25 mm. 2 210mg / 1540.25mm 2 220mg / 1540.25mm 2 230mg / 1540.25mm 2 240mg / 1540.25mm 2 250mg / 1540.25mm 2 260mg / 1540.25mm 2 270mg / 1540.25mm 2 280mg / 1540.25mm 2 290mg / 1540.25mm 2 300mg / 1540.25mm 2 310mg / 1540.25mm 2 320mg / 1540.25mm 2 330mg / 1540.25mm 2 340mg / 1540.25mm 2 350mg / 1540.25mm 2 360mg / 1540.25mm 2 370mg / 1540.25mm 2 Or a range consisting of any two of the above values.

[0537] 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.

[0538] 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.

[0539] 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.

[0540] The positive current collector can be aluminum.

[0541] 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.

[0542] 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.

[0543] 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.

[0544] The positive electrode sheet does not exclude other additional functional layers besides the positive electrode film layer. For example, in some embodiments, the positive electrode sheet of this application further includes a positive conductive layer sandwiched between the positive current collector and the positive electrode film layer and disposed on the surface of the positive current collector. In other embodiments, the positive electrode sheet of this application further includes a protective layer covering the surface of the positive electrode film layer.

[0545] In some embodiments, the ratio of the thickness of the positive current collector to the thickness of the positive electrode film layer on one side is 0.05 to 0.3. Exemplarily, the ratio of the thickness of the positive current collector to the thickness of the positive electrode film layer on one side is 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, or a range consisting of any two of the above values.

[0546] When the ratio of the thickness of the positive current collector to the thickness of the positive electrode film layer on one side is within the above range, the fast charging capability and energy density of a single cell can be improved.

[0547] In some embodiments, the resistivity of the positive electrode active material powder is from 1 Ω•cm to 27.5 Ω•cm, optionally less than or equal to 20 Ω•cm, and optionally less than or equal to 11 Ω•cm. Exemplarily, the resistivity of the positive electrode active material powder 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 consisting of any two of the above values.

[0548] The powder resistivity of the positive electrode active material is relatively low, which results in relatively low resistance of the positive electrode sheet and less heat generation in a single cell.

[0549] In the embodiments of this application, the powder resistivity of the material has a well-known meaning in the art and can be tested using methods and equipment well-known in the art, such as using a PRCD1100 powder resistivity meter according to the test standard GB / T30835-2014.

[0550] In some embodiments, the specific charging capacity of the positive electrode active material at a 0.1C rate is 150 mAh / g to 170 mAh / g, optionally 157 mAh / g to 170 mAh / g. Exemplarily, the specific charging capacity of the positive electrode active material at a 0.1C rate is 150 mAh / g, 151 mAh / g, 152 mAh / g, 153 mAh / g, 154 mAh / g, 155 mAh / g, 156 mAh / g, 157 mAh / g, 158 mAh / g, 159 mAh / g, 160 mAh / g, 161 mAh / g, 162 mAh / g, 163 mAh / g, 164 mAh / g, 165 mAh / g, 166 mAh / g, 167 mAh / g, 168 mAh / g, 169 mAh / g, 170 mAh / g, or a range consisting of any two of the above values.

[0551] When the charge capacity of the positive electrode active material at a 0.1C rate is within the above range, the energy density of the single cell is relatively high.

[0552] In the embodiments of this application, the specific capacity of the active material has a meaning known in the art and can be tested using equipment and methods known in the art. The test methods for the first coulombic efficiency and the first discharge specific capacity in Appendix G of the national standard GB / T 24533-2019 can be adopted. A half-coin cell is assembled with lithium metal as the negative electrode and a sample electrode containing the above-mentioned material as the positive electrode. The half-coin cell is tested on a battery tester or other test equipment with equivalent performance at 23℃±2℃ by charging and discharging at a rate of 0.1C to obtain the coin capacity. The capacity is then divided by the mass of the electrode active material to obtain the charging specific capacity parameter.

[0553] In some embodiments, the positive electrode active material includes a lithium phosphate, which includes phosphate particles and a coating layer. The coating layer coats the surface of the phosphate particles and contains one or more elements selected from C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0554] Phosphate particles, by having a coating layer on their surface, can improve the conductivity of lithium phosphates with olivine structure, reduce the powder resistivity of the material, and help improve the migration rate of lithium ions, improve the fast charging capability of the battery, and reduce the heat generation of individual cells.

[0555] The mass percentage of olivine-structured lithium phosphate in the positive electrode active material can be greater than or equal to 80% and less than or equal to 100%, thus the positive electrode active material of this application can be considered as an olivine-structured lithium phosphate system. When the mass percentage of olivine-structured lithium phosphate is less than 100%, the positive electrode active material may also include commonly used positive electrode active materials, such as, but not limited to, at least one of lithium transition metal oxides. Examples of lithium transition metal oxides 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.

[0556] Optionally, the lithium phosphate with an olivine structure in the positive electrode active material accounts for 100% by mass.

[0557] In some embodiments, phosphate particles include those with the general formula Li x1 A y1 Me a M b P 1-c X c Y z The compound contains the following components: 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, and Mg; Me includes one or more of Mn, Fe, Co, and 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, and Ce; X includes one or more of S, Si, Cl, B, C, and N; and Y includes one or more of O and F. Phosphate particles exhibit excellent cycle stability, which is beneficial for improving the cycle performance of single-cell batteries.

[0558] For example, the chemical elements in the phosphate particles include at least Li, Fe, P, Al, and Ti, and the mass ratio of each element is (3-4): (30-35): (15-20): (0.01-0.1): (0.1-0.5).

[0559] For example, phosphate particles include one or more of LiFePO4, LiMnPO4, LiNiPO4, and LiCoPO4. During the charging and discharging process of a single battery cell, active ions such as Li undergo insertion / extraction and consumption, resulting in different molar contents of Li at different discharge states. In the examples of positive electrode active materials such as LiFePO4, LiMnPO4, LiNiPO4, and LiCoPO4, the molar contents of Li represent the initial state of the material, i.e., the state before feeding. When the positive electrode active material is applied to the battery system, the molar contents of Li may change after charge-discharge cycles. In the embodiments of this application, the molar contents of oxygen (O) in the examples of positive electrode active materials such as LiFePO4, LiMnPO4, LiNiPO4, and LiCoPO4 are only theoretical values. Lattice oxygen release can cause changes in the molar contents of oxygen (O). In reality, the molar contents of oxygen (O) may fluctuate, and all of the above situations are within the scope of protection of this application.

[0560] In some embodiments, the coating layer includes a general formula Li 3-d Fe 2-d M 2d (PO x2 ) y2 A fast ion conductor, M2 includes one or more elements from Ti, Zr, Hf, Ge and Sn, 0≤d≤1, 0<x2<5, 0<y2<4.

[0561] For example, the fast ion conductor is a material having a NASICON structure, such as one or more of lithium iron phosphate (Li2FeTi(PO4)3), lithium zirconium iron phosphate (Li2FeZr(PO4)3), and lithium iron tin phosphate (Li2FeSn(PO4)3).

[0562] Fast ion conductors with a NASICON structure are materials with ultrafast ion conduction capabilities, possessing abundant three-dimensional lithium-ion diffusion and transport channels. They exhibit advantages such as high ion conduction efficiency and strong structural stability during multiple lithium delithiation and lithium intercalation processes. Coating the surface of phosphate particles with fast ion conductors containing a NASICON structure can significantly improve the lithium-ion transport rate during multiple lithium delithiation / intercalation at the positive electrode, enhance the ionic conductivity of the positive electrode active material, improve the fast charging capability of a single cell, and further increase the specific capacity and energy density of the corresponding single cell.

[0563] In some embodiments, the coating layer also includes all-carbon.

[0564] The carbon element and the fast ion conductor can be layered. For example, the carbon element can be an independent carbon coating layer, and the fast ion conductor can be an independent fast ion conductor layer. The carbon coating layer can be applied to the surface of the phosphate particles, and the fast ion conductor layer can be located on the surface of the carbon coating layer, i.e., 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 applied to the surface of the phosphate particles, and the carbon coating layer can be located on the surface of the fast ion conductor layer, i.e., 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 layered together.

[0565] Optionally, the carbon coating layer can be formed by carbonizing an organic carbon source (e.g., glucose, polyethylene glycol, etc.) onto the surface of the fast ion conductor layer. The carbon coating layer can partially or completely cover the fast ion conductor layer. The carbon coating layer can significantly improve the electronic conductivity of phosphate particles, compensating for the poor electronic conductivity of phosphate particles and increasing the energy density of the single-cell battery.

[0566] Specifically, the carbon coating layer gives the positive electrode active material of this application the following advantages:

[0567] The carbon coating layer in the positive electrode active material of this application provides a suitable channel for electron transport, which can significantly improve the electron conduction rate during multiple lithium delithiation and lithium insertion processes, improve the electronic conductivity of lithium phosphate, improve the charging capability of the corresponding single cell, and also improve the energy density.

[0568] The carbon coating layer of the positive electrode active material in this application has a loose and porous structure, which allows the electrolyte to fully and effectively contact the lithium phosphate, thereby improving the lithium ion transport rate at the phase interface and enhancing the charging capability of the single cell.

[0569] Coating the surface of lithium phosphate with a carbon coating layer can not only improve the conductivity of lithium phosphate, but also improve the structural stability of the positive electrode active material. This effectively alleviates the iron dissolution phenomenon of the positive electrode active material during long-term storage and cyclic use of the single cell, thereby improving the cycle life of the single cell.

[0570] The positive electrode active material of this application uses lithium phosphate as a substrate, fully leveraging the advantages of lithium phosphate such as low cost, high reliability, and good cycle stability. Simultaneously, it utilizes coating layers (a fast ion conductor layer and a carbon coating layer) to overcome the drawbacks of poor electronic and ionic conductivity. The single-cell battery prepared using the positive electrode active material of this application can improve the energy density of the single-cell battery while maintaining excellent cycle performance.

[0571] In this embodiment, the elemental content in the positive electrode active material is defined in a way known in the art and can be detected using equipment and methods known in the art. For example, referring to EPA 6010D-2014, it can be tested by inductively coupled plasma atomic emission spectrometry (ICP-OES, instrument model: Thermo ICAP7400). After discharging the single cell to 0% state of charge (SOC), the positive electrode sheet is disassembled, cleaned with DMC and dried, and then calcined at high temperature to remove impurities. 0.4g of the positive electrode active material is weighed and 10ml (50% concentration) of aqua regia is added. Then it is placed on a plate at 180℃ for 30min. After digestion on the plate, the volume is adjusted to 100mL, and quantitative testing is performed using the standard curve method.

[0572] In some embodiments, the degree of graphitization of the positive electrode active material is 0.15 to 0.32, optionally 0.19 to 0.26. Exemplarily, the degree of graphitization of the positive electrode active material is 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, or a range consisting of any two of the above values.

[0573] When the degree of graphitization of the positive electrode active material is within the above range, it is beneficial to improve the conductivity of the positive electrode active material, reduce the heat generation of the positive electrode sheet, and thus reduce the heat generation of the single cell.

[0574] In the embodiments of this application, the higher the degree of graphitization of the material, the lower the degree of disorder, which can be tested according to the testing standard JIS / K 0131-1996 "General Rules for X-ray Diffraction Analysis".

[0575] In some embodiments, the carbon content in the olivine-structured lithium phosphate is 1% to 2% by mass, and the specific surface area of ​​the olivine-structured lithium phosphate is 5 m². 2 / g to 18m 2 / g.

[0576] Optionally, the carbon content in the olivine-structured lithium phosphate is 1% to 2% by mass, and the specific surface area of ​​the olivine-structured lithium phosphate is 7.5 m². 2 / g to 14m 2 / g.

[0577] For example, the mass content of carbon in the lithium phosphate with olivine structure is 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, or any combination of two of the above values.

[0578] For example, the specific surface area of ​​lithium phosphate with an olivine structure is 5 m². 2 / g、6m 2 / g、7m 2 / g、8m 2 / g、9m 2 / g, 10m 2 / g、11m 2 / g、12m 2 / g、13m 2 / g、14m 2 / g, 15m 2 / g, 16m 2 / g、17m 2 / g、18m 2 / g or a range consisting of any two of the above values.

[0579] Carbon primarily exists in the material as a carbon coating layer. This porous carbon coating layer increases the material's specific surface area, facilitating effective contact between the electrolyte and phosphate particles and promoting lithium-ion transport at the phase interface. Furthermore, when the carbon content falls within the aforementioned range, it significantly improves the conductivity of olivine-structured lithium phosphates, enhancing both ionic and electronic conductivity, thereby increasing the rapid charging capability and energy density of individual battery cells.

[0580] In the embodiments of this application, the specific surface area of ​​the material has a meaning known in the art and can be detected using equipment and methods known in the art. For example, it can be detected according to the testing standard GB / T 19587-2017, using the positive electrode active material as a sample, and the specific surface area is tested using a Tri-Star 3020 specific surface area and pore size analyzer from Micromeritics, USA.

[0581] In some embodiments, the volume distribution particle size of the positive electrode active material satisfies: 1µm≤Dv50≤2µm, 0.4µm≤Dv10≤0.7µm.

[0582] For example, the Dv50 of the positive electrode active material can be 1µm, 1.1µm, 1.15µm, 1.2µm, 1.25µm, 1.3µm, 1.35µm, 1.4µm, 1.45µm, 1.5µm, 1.55µm, 1.6µm, 1.65µm, 1.7µm, 1.75µm, 1.8µm, 1.85µm, 1.9µm, 1.95µm, 2µm, or any range of two of the above values.

[0583] For example, the Dv10 of the positive electrode active material can be 0.4µm, 0.45µm, 0.5µm, 0.55µm, 0.6µm, 0.65µm, 0.7µm, or any range of two of the above values.

[0584] The positive electrode active material has a relatively small particle size, resulting in a shorter lithium ion insertion / extraction path and less heat generation. Furthermore, the particle size of the positive electrode active material is not too small, so it will not agglomerate during the processing and preparation process, thus ensuring the stable performance of the positive electrode active material.

[0585] In the embodiments of this application, the volume average particle size Dv50 of the material refers to the particle size corresponding to 50% of the volume distribution, and the volume average particle size Dv10 of the material refers to the particle size corresponding to 10% of the volume distribution. They can be detected using equipment and methods known in the art. For example, the positive electrode active material can be used as a sample, and the Dv50 and Dv10 of the particles can be tested using a Mastersizer 2000E laser particle size analyzer according to the test standard GB / T 19077-2016.

[0586] When the positive electrode active material includes not only lithium phosphate with an olivine structure but also other materials, the volume distribution particle size of the positive electrode active material refers to the volume distribution particle size of all positive electrode active materials.

[0587] In some embodiments, the olivine-structured lithium phosphate is particulate, comprising secondary particles, which in turn comprise a plurality of primary particles, the average particle size of which 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 consisting of any two of the above values.

[0588] The average particle size of primary particles is relatively small, the lithium ion insertion / extraction path in the positive electrode active material is shorter, and the heat generation is less.

[0589] In this embodiment, secondary particles refer to aggregated particles formed by the aggregation of two or more primary particles. Primary and secondary particles can be easily distinguished experimentally (e.g., by taking SEM images using a scanning electron microscope). The average particle size of primary particles can be obtained by testing the SEM images. The SEM test parameters can be set as follows: operating voltage (EHT) of 10.00 kV, using an InLens detector, operating distance of 4.6 mm, and magnification of 1000X.

[0590] In some embodiments, the positive electrode film layer further includes one or more of the following: ternary materials, lithium phosphate, lithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium molybdate, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganese oxide, lithium tartrate, lithium trilithium citrate, lithium nickel oxide, and lithium ferrite. These materials can act as lithium replenishing agents, which can replenish lithium ions to the positive electrode film layer, compensate for irreversible lithium ion losses within the system, increase capacity, and thereby improve the energy density of the single-cell battery.

[0591] Optionally, ternary materials include Li x3 A y3 Ni a3 Co b3 Mn c M3 (1-a3-b3-c3) Y3 z3 Wherein, 0 < x3 ≤ 2.1, 0 < y3 ≤ 2.1, and 0.9 ≤ x3 + y3 ≤ 2.1, 0 ≤ a3 ≤ 1, 0 ≤ b3 ≤ 1, 0 ≤ c3 ≤ 1, and 0.1 ≤ a3 + b3 + c3 ≤ 1, 1.8 ≤ z3 ≤ 3.5, A includes one or more of Na, K, and Mg, M3 includes one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce, and Y3 includes one or more of O and F.

[0592] For example, ternary materials include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (NCM523), LiNi 0.6 Co 0.2 Mn 0.2 O2 (NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (NCM811), LiNi 0.80 Co 0.15 Al 0.05 At least one of O2.

[0593] In some embodiments, the mass content of the lithium replenishing agent 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 any combination of two of the above values. When the mass content of the lithium replenishing agent is within the above range, it can replenish lithium ions to the positive electrode film layer, compensate for irreversible lithium ion loss in the system, increase capacity, and thereby increase the energy density of the single cell.

[0594] The lithium replenishing agent can be located in the same layer as the positive electrode active material or in a different layer. When the lithium replenishing agent and the positive electrode active material are in different layers, the lithium replenishing agent can be located in the lithium replenishing layer, and the positive electrode active material can be located in the positive electrode active material layer. In other words, the positive electrode film layer includes a lithium replenishing layer and a positive electrode active material layer. The positive electrode active material layer can be disposed on at least one side of the positive electrode current collector, and the lithium replenishing layer can be located between the positive electrode active material layer and the positive electrode current collector. Alternatively, the lithium replenishing layer can be disposed on at least one side of the positive electrode current collector, and the positive electrode active material layer can be located between the lithium replenishing layer and the positive electrode current collector. Optionally, the lithium replenishing layer can be located between the positive electrode active material layer and the positive electrode current collector. During the cycle charging and discharging of a single cell, the lithium replenishing agent in the lithium replenishing layer can be gradually released into the system to compensate for the lithium loss of the battery system.

[0595] In some embodiments, the positive electrode film may optionally include a positive electrode conductive agent. This application does not impose any particular limitation on the type of positive electrode conductive agent. As an example, the positive electrode conductive agent includes at least one of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0596] In some embodiments, the mass content of the positive electrode conductive agent is ≤5% based on the mass of the positive electrode film.

[0597] In some embodiments, the positive electrode film layer may optionally include a positive electrode binder. This application does not impose particular limitations on the type of positive electrode binder. As an example, the positive electrode binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polyacrylic acid, and fluorinated acrylate resins. In some embodiments, the mass content of the positive electrode binder is ≤5% based on the mass of the positive electrode film layer.

[0598] In some embodiments, the positive current collector may be a metal foil or a composite current collector. Examples of metal foils include at least one foil selected from aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. The composite current collector may include a polymeric material substrate and a metal material layer formed on at least one surface of the polymeric material substrate. As an example, the metal material layer may include at least one selected from aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymeric material substrate may include at least one selected from polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0599] In some embodiments, the positive electrode further includes a positive conductive layer located between the positive electrode film and the positive current collector. The positive conductive layer can further improve the conductivity of the positive electrode and reduce the heat generation of the positive electrode, thereby reducing the heat generation of a single battery cell.

[0600] In some embodiments, the thickness of the positive electrode conductive layer is from 0.5 μm to 2 μm. Exemplarily, the thickness of the positive electrode conductive layer can be 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.6 μm, 1.8 μm, 2 μm, or any range of two of the above values.

[0601] When the thickness of the positive electrode conductive layer is within the above range, the conductivity of the positive electrode sheet can be further improved, the heat generation of the positive electrode sheet can be reduced, thereby reducing the heat generation of the individual cell, and the energy density of the individual cell can also be improved.

[0602] In the embodiments of this application, the thickness of the positive electrode conductive layer has a meaning known in the art and can be detected using equipment and methods known in the art, such as performing a tomographic scan on the positive electrode sheet to directly measure the thickness of the positive electrode conductive layer.

[0603] In some embodiments, the positive electrode conductive layer includes one or more of a positive electrode conductive agent and a positive electrode binder.

[0604] Optionally, the mass content of the positive electrode conductive agent in the positive electrode conductive layer is 30% to 50%. For example, the mass content of the positive electrode conductive agent is 30%, 35%, 40%, 45%, 50%, or any combination of two of the above values.

[0605] For example, the positive electrode conductive agent includes one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. The positive electrode conductive agent in the positive electrode conductive layer can improve the conductivity of the positive electrode conductive layer, thereby improving the conductivity of the positive electrode sheet and reducing the heat generation of a single battery cell.

[0606] Optionally, the mass content of the positive electrode binder in the positive electrode conductive layer is 50% to 70%. For example, the mass content of the positive electrode binder is 50%, 60%, 65%, 70%, or any combination of two of the above values.

[0607] For example, the positive electrode binder includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, a terpolymer of vinylidene fluoride-tetrafluoroethylene-propylene, a terpolymer of vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene, a tetrafluoroethylene-hexafluoropropylene copolymer, polyacrylic acid, and fluorinated acrylate resins. 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, thereby enhancing the structural stability of the positive electrode sheet.

[0608] [Isolation membrane]

[0609] In some embodiments, the separator includes a base membrane having a porous structure, the porosity of which is 20% to 70%, optionally 35% to 60%. Exemplarily, the porosity of the base membrane is 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or any range of two of the above values.

[0610] When the porosity of the base film in the embodiments of this application is within the above-mentioned range, it can enhance the migration ability of lithium ions in the separator, further reduce the internal resistance of the single cell, and thus reduce heat generation.

[0611] In this embodiment, porosity refers to the percentage of the volume of the pores in the separator membrane to the total volume of the separator membrane. Porosity can be tested according to the standard GB / T36363-2018 "Polyolefin Separators for Monomeric Battery Cells". It should be noted that the actual testing process may differ slightly from the standard due to differences in testing instruments, testing errors, and to minimize the impact on porosity testing, in order to obtain more accurate test values.

[0612] In some embodiments, the thickness of the base film can be, but is not limited to, 6 μm to 12 μm, and may be 6 μm to 9 μm. Exemplarily, the thickness of the base film is 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 20.5 μm, or a range consisting of any two of the above values.

[0613] Alternatively, the base film can be made of polypropylene.

[0614] When the thickness of the base film is within the above range, the migration path of lithium ions in the base film is shorter, which can further reduce the internal resistance of the individual cell and thus reduce heat generation.

[0615] In this embodiment, the separator can be a base film. Optionally, the separator further includes a functional layer disposed on at least one side of the base film. The functional layer may include inorganic particles to improve the heat resistance of the separator. Optionally, the functional layer is disposed on both sides of the base film.

[0616] In some embodiments, the functional layer includes a first functional layer and a second functional layer. The first functional layer is located on one side of the base film and includes first inorganic particles. The second functional layer is located on the other side of the base film and includes composite particles. The composite particles include second inorganic particles and a plurality of non-fluoropolymer particles. The second inorganic particles are attached to the surface of the non-fluoropolymer particles and / or dispersed inside the non-fluoropolymer particles.

[0617] The first and second functional layers have good heat resistance, which can improve the heat resistance of the separator.

[0618] Optionally, the first functional layer may include an adhesive, optionally including at least one of a fluorinated adhesive or a polyacrylic adhesive, such as polyvinylidene fluoride.

[0619] Optionally, the first inorganic particles include one or more of silicon oxide, aluminum oxide, boehmite, barium sulfate, calcium oxide, titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, and tin oxide. These first inorganic particles can improve the heat resistance of the first functional layer.

[0620] In the embodiments of this application, the thickness of the base film has a meaning known in the art and can be detected using methods and equipment known in the art. For example, a newly prepared separator can be taken as a sample, or a single cell that has been completely discharged (discharged to the lower limit cutoff voltage so that the battery's state of charge is about 0% SOC) can be disassembled in reverse, the separator can be obtained from the single cell, and the separator can be dried and used as a sample. The separator can be cut with an ion beam cutter to form a cross section, and then the thickness of the separator and its various layers can be measured using a scanning electron microscope.

[0621] In the second functional layer, the non-fluorinated polymer particles refer to polymers that are non-fluorinated polymers. For example, non-fluorinated polymer particles include acrylate copolymers. Optionally, acrylate copolymers include acrylate-acrylonitrile-acrylamide-propylene copolymers. Acrylate copolymers have excellent adhesion properties and high adhesion stability to the base film. The molar ratio of each monomer in the copolymer can be arbitrary, for example, a molar ratio of 35%:30%:15%:20%, or 40%:20%:10%:30%, or 45%:15%:20%:20%, etc.

[0622] The second inorganic particle in the composite particles prevents the non-fluoropolymer particles from sticking together due to the high-temperature treatment during granulation. This creates porosity within the composite particles, facilitating lithium-ion transport and enhancing the ion-conductivity of the separator. Furthermore, the second inorganic particle increases the compressive modulus of the composite particles, reducing their deformation during charging and discharging. This results in a more stable separator structure, improving the kinetic performance of the individual battery cell and enhancing fast-charging performance. Optionally, compared to the first functional layer, the second functional layer is positioned closer to the negative electrode. Because the composite particles are less prone to deformation, the separator exerts minimal pressure or other side effects on the negative electrode, ensuring stable kinetic performance. Correspondingly, the first functional layer is positioned closer to the positive electrode.

[0623] Optionally, the second inorganic particles include one or more of silicon oxide, aluminum oxide, boehmite, barium sulfate, calcium oxide, titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, and tin oxide. Optionally, the second inorganic particles include silicon oxide. These second inorganic particles can improve the heat resistance of the second functional layer and can combine with non-fluoropolymers to form composite particles, further improving the cycle stability and kinetic performance of the separator, and improving the cycle performance and fast charging performance of the individual battery cell.

[0624] The average particle size of the second inorganic particles is 5 nm to 100 nm, optionally 10 nm to 100 nm, or optionally 5 nm to 20 nm. For example, 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 any combination of two of the above values. When the average particle size of the second inorganic particles is within the above range, it is beneficial to improve the heat resistance and compressive modulus of the composite particles.

[0625] In the embodiments of this application, the average particle size of the second inorganic particles has a meaning known in the art and can be detected using equipment and methods known in the art. For example, after obtaining the separator membrane and drying it as a sample, the separator membrane is cut with an ion beam cutter to form a cross-section. Subsequently, the particle size of the second inorganic particles in the separator membrane is measured using a scanning electron microscope. The particle size of multiple, for example, 50, second inorganic particles is measured, and their average value is calculated as the average particle size of the second inorganic particles.

[0626] In some embodiments, the ionic conductivity of the separator is from 0.3 mS / cm to 0.6 mS / cm. Exemplarily, the ionic conductivity of the separator is 0.3 mS / cm, 0.35 mS / cm, 0.4 mS / cm, 0.45 mS / cm, 0.5 mS / cm, 0.55 mS / cm, 0.6 mS / cm, or any range of two of the above values.

[0627] When the ionic conductivity of the separator is within the above range, it can further enhance the separator's ability to migrate lithium ions and improve the fast charging performance of a single battery cell.

[0628] In this application embodiment, the ionic conductivity of the separator has a meaning known in the art and can be detected using equipment and methods known in the art, for example,

[0629] Preparation of the 2025-type button cell for testing: In a vacuum glove box, a lithium sheet was placed in the negative electrode shell of the battery, and 150 μL of electrolyte was added. The electrolyte was a solution of 1 mol / L LiPF6 in EC / EMC / DEC = 3 / 5 / 2 (mass ratio). Then, a separator (with an area of ​​3.14 cm²) was placed inside. 2 The electrode (12 μm thick) is tightly attached to the lithium sheet, then 25 μL of electrolyte is added, and finally the positive electrode (which can be the positive electrode from Example 1) is placed on top and sealed. The assembled button cell is removed from the vacuum glove box and left for 24 hours for further testing.

[0630] Test: At an electrochemical workstation, at 10 -1 ~10 6 The isolation film resistance Rb was obtained by testing within a frequency range of Hz, and the ionic conductivity σ (unit: mS / cm) was calculated using the following formula.

[0631] σ=L / (R b ×S)

[0632] Where: R b Let L be the resistance of the isolation membrane, and S be the thickness and area of ​​the isolation membrane under test, respectively.

[0633] In some embodiments, the base film includes at least one of glass fiber, nonwoven fabric, and polyolefin. The base film can be a single-layer film or a multi-layer composite film, without particular limitation. When the base film is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0634] Optionally, the polyolefin includes at least one of polyethylene, polypropylene, and polyvinylidene fluoride.

[0635] In some embodiments, the positive electrode, the separator, and the negative electrode can be fabricated into an electrode assembly by a winding process and / or a stacking process.

[0636] Figure 23 and Figure 24 A schematic diagram of a single battery cell is shown.

[0637] In some embodiments, the individual battery cell 7 may include a housing 20.

[0638] In some embodiments, the outer casing 20 of the individual battery cell 7 can be a rigid casing, such as a rigid plastic casing, an aluminum casing, a steel casing, etc. The outer casing 20 of the individual battery cell 7 can also be a soft package, such as a pouch-type 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).

[0639] The outer shell 20 is a hollow structure, and the outer shell 20 can be used to encapsulate the electrode assembly 10 and the electrolyte.

[0640] The method for preparing the single-cell battery 7 according to the embodiments of this application is well known. In some embodiments, a positive electrode, a separator, a negative electrode, and an electrolyte can be assembled to form a single-cell battery 7. As an example, the positive electrode, the separator, and the negative electrode can be formed into an electrode assembly 10 by a winding process and / or a stacking process. The electrode assembly 10 is placed in a housing 20, dried, and then injected with an electrolyte. After vacuum sealing, settling, formation, shaping, and other processes, a single-cell battery 7 is obtained.

[0641] In some embodiments, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening and the end cap 22 covering the opening.

[0642] The shape of the housing 21 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cylindrical structure, a cylindrical housing can be selected; if the electrode assembly 10 is a cuboid structure, a cuboid housing can be selected. Optionally, both the electrode assembly 10 and the housing 21 are cuboid structures.

[0643] In some embodiments, the housing 21 is made of steel, which has high mechanical strength, is not easily deformed, and can improve the reliability and cycle performance of the individual battery cell. Optionally, steel accounts for the largest proportion of the mass in the housing 21.

[0644] Optionally, the thickness of the housing 21 is 0.1 mm to 0.5 mm, and optionally 0.2 mm to 0.35 mm. For example, the thickness of the housing 21 is 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, or any combination of two of the above values. When the thickness of the housing 21 is within the above range, the mechanical strength of the housing 21 is high, which can improve the reliability and cycle performance of the single cell 7. Furthermore, the housing 21 occupies less space, and the internal space of the housing 21 is larger, which is beneficial to increasing the energy density of the single cell 7.

[0645] From the external shape of the electrode assembly 10, the electrode assembly 10 includes a main body 12, a first electrode tab 11, and a second electrode tab 13, which protrude from the main body 12. The first electrode tab 11 is the portion of the first electrode sheet without an active material layer, and the second electrode tab 13 is the portion of the second electrode sheet without an active material layer. The first electrode tab 11 and the second electrode tab 13 are used to draw current from the main body 12. The first electrode sheet and the second electrode sheet have opposite polarities; in other words, one of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other is a negative electrode sheet. Of course, the first electrode tab 11 can be a positive electrode tab, and the second electrode tab 13 can be a negative electrode tab.

[0646] Taking the first tab 11 as the negative electrode tab and the second tab 13 as the positive electrode tab as an example, the portion of the negative electrode current collector in the negative electrode sheet that is not coated with an active material layer is the negative electrode tab. The active material coated on the negative electrode current collector in the negative electrode sheet constitutes the negative electrode film layer. The negative electrode film layer and the negative electrode current collector coated with the active material are part of the main body 12. Similarly, the portion of the positive electrode current collector in the positive electrode sheet that is not coated with an active material layer is the positive electrode tab. The active material coated on the positive electrode current collector in the positive electrode sheet constitutes the positive electrode film layer. The positive electrode film layer and the positive electrode current collector coated with the active material are part of the main body 12.

[0647] The first tab 11 and the second tab 13 can extend from the same side of the main body 12, or they can extend from opposite sides respectively.

[0648] Optionally, the number of first tabs 11 located on the same side of the main body 12 is at least one, and optionally at least two. At least two first tabs 11 can increase the current carrying capacity of the first tabs 11.

[0649] Optionally, the number of second tabs 13 located on the same side of the main body 12 is at least one, and optionally at least two. At least two second tabs 13 can increase the current carrying capacity of the second tabs 13.

[0650] In some embodiments, the single cell 7 further includes a first electrode terminal 31, which is electrically connected to the first tab 11. Optionally, the first electrode terminal 31 and the first tab 11 are welded together. The first electrode terminal 31 and the first tab 11 can be connected by an adapter, or they can be connected without an adapter. Optionally, the first electrode terminal 31 and the first tab 11 are directly welded together without an adapter, which can reduce the resistance at the connection point and help reduce the overall internal resistance of the single cell 7.

[0651] When the first tab 11 is the negative tab, the first electrode terminal 31 is the negative terminal. When the first tab 11 is the positive tab, the first electrode terminal 31 is the positive terminal.

[0652] In some embodiments, the individual battery cell 7 further includes a second electrode terminal 32, which is electrically connected to the second tab 13. Optionally, the second electrode terminal 32 and the second tab 13 are welded together. The second electrode terminal 32 and the second tab 13 can be connected by an adapter, or they can be connected without an adapter. Optionally, the second electrode terminal 32 and the second tab 13 are directly welded together without an adapter, which can reduce the resistance at the connection point and help reduce the overall internal resistance of the individual battery cell 7.

[0653] When the second electrode tab 13 is the negative electrode tab, the second electrode terminal 32 is the negative terminal. When the second electrode tab 13 is the positive electrode tab, the second electrode terminal 32 is the positive terminal.

[0654] Optionally, the number of first electrode terminals 31 located on the same side of the main body 12 is at least one, and optionally at least two. At least two first electrode terminals 31 can increase the current-carrying capacity of the first electrode terminals 31.

[0655] Alternatively, the current-passing area of ​​the first electrode terminal 31 on one side is 150 mm². 2 Up to 1000mm 2 200mm is optional 2 Up to 1000mm 2 The current-carrying area of ​​a single-sided first electrode terminal 31 refers to the sum of the current-carrying areas of all first electrode terminals 31 located on the same side of the main body 12. The current-carrying 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 cap 22.

[0656] For example, the current-passing area of ​​the first electrode terminal 31 on one side can be 150 mm². 2 200mm 2 210mm 2 250mm 2280mm 2 300mm 2 320mm 2 350mm 2 380mm 2 400mm 2 450mm 2 500mm 2 550mm 2 600mm 2 650mm 2 700mm 2 750mm 2 800mm 2 850mm 2 900mm 2 950mm 2 1000mm 2 Or a range consisting of any two of the above values.

[0657] Optionally, the number of second electrode terminals 32 located on the same side of the main body 12 is at least one, and optionally at least two. At least two second electrode terminals 32 can increase the current carrying capacity of the second electrode terminals 32.

[0658] Alternatively, the current-passing area of ​​the second electrode terminal 32 on one side is 150 mm². 2 Up to 1000mm 2 200mm is optional 2 Up to 1000mm 2 The current-carrying area of ​​a single-sided second electrode terminal 32 refers to the sum of the current-carrying areas of all second electrode terminals 32 located on the same side of the main body 12. The current-carrying area of ​​the second electrode terminal 32 can be understood as the cross-sectional area of ​​the second electrode terminal 32, which is perpendicular to the thickness direction of the end cap 22.

[0659] For example, the current-passing area of ​​the second electrode terminal 32 on one side can be 150 mm². 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.

[0660] 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.

[0661] 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.

[0662] 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.

[0663] 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.

[0664] The first housing portion 5a and the second housing portion 5b overlap each other, and together they define a receiving space 5c for accommodating a single battery cell. The second housing portion 5b can be a hollow structure with one open end, and the first housing portion 5a is a plate-like structure. The first housing portion 5a covers the open side of the second housing portion 5b to form a housing 5 with the receiving space 5c. Alternatively, both the first housing portion 5a and the second housing portion 5b can be hollow structures with one open side, and the open side of the first housing portion 5a covers the open side of the second housing portion 5b to form a housing 5 with the receiving space 5c. Of course, the first housing portion 5a and the second housing portion 5b can be various shapes, such as cylinders, cuboids, etc.

[0665] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0666] Assuming that the first box part 5a covers the top of the second box part 5b, the first box part 5a can also be called the upper box cover, and the second box part 5b can also be called the lower box.

[0667] In some embodiments, during the charging process of the battery pack 2 or any individual cell comprising the battery pack 2 from 0% state of charge (SOC) to 100% SOC, the ambient temperature of the external environment in which the battery pack 2 is located is 30°C.

[0668] In some embodiments, during the charging process of the battery pack 2 or any individual cell comprising the battery pack 2 from 10% state of charge (SOC) to 80% SOC, the ambient temperature of the external environment in which the battery pack 2 is located is 30°C.

[0669] In some embodiments, the charging process of the battery pack 2 or any individual cell comprising the battery pack 2 from 10% state of charge to 80% state of charge includes multiple charging steps. The difference between the maximum state of charge in any charging step and the maximum state of charge in the 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 any range of any two of the above values.

[0670] The charging process of the battery pack 2 or any individual cell comprising the battery pack 2 from 10% state of charge to 40% state of charge includes multiple charging steps. For any charging step, the charging rate can be any ratio between 5C and 10C. The charging rate corresponding to each charging step can be any value of 5C, 5.5C, 6C, 6.5C, 7C, 7.5C, 8C, 8.5C, 9C, 9.5C, 10C, or a value within the range of any two of the above values.

[0671] The charging process from 40% state of charge to 80% state of charge in the battery pack 2 or any individual cell comprising the battery pack 2 also includes multiple charging steps. The charging rate of any charging step is less than the charging rate of any charging step from 10% state of charge to 40% state of charge, and the charging rate of the step to 80% state of charge is any value from 2.5C to 5C, for example, it can be 2.7C.

[0672] For example, the charging process from 10% to 80% for the battery pack 2 or any individual cell comprising the battery pack 2 can be performed as follows:

[0673] Charge from 10% SOC to 15% SOC at a constant current of 5.0C.

[0674] Charge from 15% SOC to 20% SOC at a constant current of 5.0C.

[0675] Charge from 20% SOC to 25% SOC at a constant current of 5.0C.

[0676] Charge from 25% SOC to 30% SOC at a constant current of 5.0C.

[0677] Charge from 30% SOC to 35% SOC at a constant current of 5.0C.

[0678] Charge from 35% SOC to 40% SOC at a constant current of 5.0C.

[0679] Charge from 40% SOC to 45% SOC at a constant current of 4.6C.

[0680] Charge from 45% SOC to 50% SOC at a constant current of 4.3C.

[0681] Charge from 50% SOC to 55% SOC at a constant current of 4.0C.

[0682] Charge from 55% SOC to 60% SOC at a constant current of 3.7C.

[0683] Charge from 60% SOC to 65% SOC at a constant current of 3.4C.

[0684] Charge from 65% SOC to 70% SOC at a constant current of 3.1C.

[0685] Charge from 70% SOC to 75% SOC at a constant current of 2.9C.

[0686] Charge from 75% SOC to 80% SOC at a constant current of 2.7C.

[0687] In some embodiments, the charging time for the battery pack 2 or any individual cell comprising the battery pack 2 from 10% state of charge to 80% state of charge is less than or equal to 10.5 min, optionally ranging from 5 min to 10.5 min, and the ambient temperature of the battery pack 2 at 10% state of charge is room temperature, for example, 30°C. Exemplarily, the charging time for the battery pack 2 from 10% state of charge to 80% state of charge is 10.5 min, 10 min, 9.5 min, 9 min, 8.5 min, 8 min, 7.5 min, 7 min, 6.5 min, 6 min, 5.5 min, 5 min, or a range of any two of the above values.

[0688] In some embodiments, the volumetric energy density of a single battery cell can be, but is not limited to, 390 Wh / L to 500 Wh / L, and optionally 410 Wh / L to 470 Wh / L. Exemplarily, the volumetric energy density of a single battery cell is 290 Wh / L, 300 Wh / L, 320 Wh / L, 350 Wh / L, 370 Wh / L, 390 Wh / L, 400 Wh / L, 410 Wh / L, 420 Wh / L, 430 Wh / L, 440 Wh / L, 450 Wh / L, 460 Wh / L, 470 Wh / L, 480 Wh / L, 490 Wh / L, 500 Wh / L, or a range of any two of the above values. The volumetric energy density of the single battery cell is relatively high.

[0689] In the embodiments of this application, the volumetric energy density of a single battery cell has a meaning known in the art and can be detected using equipment and methods known in the art. For example, the following description uses a battery charging upper limit voltage of 3.65V and a battery discharging cutoff voltage of 2.0V as an example.

[0690] Place the individual battery cell at 25℃ and charge it to 3.65V with a constant current of 0.33C, then charge it to 0.05C with a constant voltage, and discharge it to 2.0V with a constant current of 0.33C. Record the discharge capacity A0 at this point, in Ah. Use calipers to measure the length, width, and height of the individual battery cell (generally calculated based on the battery casing dimensions, excluding the height of the electrode terminals and the insulating film outside the casing). Calculate the volume of the individual battery cell V0, in L. The volumetric energy density of the individual battery cell VED = (A0 × discharge plateau voltage) / V0, in Wh / L.

[0691] The volumetric energy density of a single battery cell ranges from 290Wh / L to 500Wh / L, enabling the energy storage unit to store a large amount of electrical energy within a limited space, providing a stable and sufficient energy guarantee for the high-power output of the charging module 120. During fast charging, the high energy density of the single battery cell allows the energy storage unit to continuously supply power to the charging module 120, further optimizing the performance of the charging device 100 and ensuring stable operation of the charging device 100 at high power output.

[0692] Electrical equipment

[0693] The second aspect of this application provides an electrical device, which includes a battery device according to the embodiments of this application, such as a single battery cell, a battery module, or a battery pack. The single battery cell, battery module, or battery pack can be used as a power source for the electrical device or as an energy storage unit for the electrical device. The electrical device can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Vehicles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0694] Electrical equipment can be selected from individual battery cells, battery modules, or battery packs according to its usage requirements.

[0695] Figure 27 This is a schematic diagram of an example electrical device 1. This electrical device 1 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of this electrical device 1, a battery pack or battery module can be used.

[0696] The electrical equipment 1 has a battery pack 2 installed inside. The battery pack 2 can be located at the bottom, head, or tail of the electrical equipment 1. The battery pack 2 can be used to power the electrical equipment 1. For example, the battery pack 2 can be used as the operating power source for the electrical equipment 1, and it can also be used as the driving power source for the electrical equipment 1, replacing or partially replacing fuel oil or natural gas to provide driving power for the electrical equipment 1.

[0697] Electrical equipment 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery pack 2 to supply power to the motor 4, for example, to meet the power needs of electrical equipment 1 during startup, navigation and driving.

[0698] Another example of a power-consuming device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design, and can utilize a single battery cell as their power source.

[0699] The charging process for the electrical equipment can be selected using the following charging methods:

[0700] Charge from 10% SOC to 15% SOC at a constant current of 5.0C.

[0701] Charge from 15% SOC to 20% SOC at a constant current of 5.0C.

[0702] Charge from 20% SOC to 25% SOC at a constant current of 5.0C.

[0703] Charge from 25% SOC to 30% SOC at a constant current of 5.0C.

[0704] Charge from 30% SOC to 35% SOC at a constant current of 5.0C.

[0705] Charge from 35% SOC to 40% SOC at a constant current of 5.0C.

[0706] Charge from 40% SOC to 45% SOC at a constant current of 4.6C.

[0707] Charge from 45% SOC to 50% SOC at a constant current of 4.3C.

[0708] Charge from 50% SOC to 55% SOC at a constant current of 4.0C.

[0709] Charge from 55% SOC to 60% SOC at a constant current of 3.7C.

[0710] Charge from 60% SOC to 65% SOC at a constant current of 3.4C.

[0711] Charge from 65% SOC to 70% SOC at a constant current of 3.1C.

[0712] Charge from 70% SOC to 75% SOC at a constant current of 2.9C.

[0713] Charge from 75% SOC to 80% SOC at a constant current of 2.7C.

[0714] In some embodiments, the charging time for the electrical device from 10% state of charge to 80% state of charge is less than or equal to 10.5 minutes, optionally ranging from 5 minutes to 10.5 minutes, and the ambient temperature of the battery pack 2 at 10% state of charge is room temperature, for example, 30°C. Exemplarily, the charging time for 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 of any two of the above values.

[0715] Example

[0716] The following embodiments describe the contents disclosed in this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of the embodiments of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0717] Example 1

[0718] 1. Preparation of positive electrode sheet

[0719] The positive electrode includes a positive current collector, a positive conductive layer on the positive current collector, and a positive film layer. The positive current collector is an aluminum foil with a thickness of 10 μm.

[0720] The positive electrode conductive layer on the positive electrode current collector is a film formed by uniformly mixing the positive electrode conductive agent superconducting carbon, the positive electrode binder polyvinylidene fluoride (PVDF), and the solvent N-methylpyrrolidone (NMP), coating it on the surface of the current collector, and drying it. The thickness is 1μm. The positive electrode conductive layer contains 40% positive electrode conductive agent by mass and 60% positive electrode binder by mass.

[0721] The positive electrode film layer comprises a film layer formed by uniformly coating the surface of the positive electrode conductive layer with a positive electrode slurry (solvent being N-methylpyrrolidone (NMP)) and then drying and cold pressing. The positive electrode film layer comprises positive electrode active material, binder polyvinylidene fluoride (PVDF), and conductive agent acetylene black in a weight ratio of 97:2:1.

[0722] The positive electrode active material includes lithium iron phosphate and a coating layer. The coating layer is coated on the surface of the lithium iron phosphate and 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.

[0723] The single-sided coating weight of the positive electrode film is 300 mg / 1540.25 mm. 2 .

[0724] 2. Preparation of negative electrode sheet

[0725] The negative electrode sheet includes a negative current collector, a negative conductive layer on the negative current collector, and a negative film layer. The negative current collector is a copper foil with a thickness of 5μm.

[0726] The negative electrode conductive layer on the negative electrode current collector is a film formed by uniformly mixing the negative electrode conductive agent superconducting carbon, the negative electrode binder styrene-butadiene rubber SBR, the thickener sodium carboxymethyl cellulose (CMC-Na) and the solvent water, coating it on the surface of the negative electrode current collector and drying it. The thickness is 1μm. 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 thickener in the negative electrode conductive layer is 5%.

[0727] The negative electrode film is formed by uniformly coating the negative electrode slurry (with deionized water as the solvent) onto the surface of the negative electrode conductive layer, followed by drying and cold pressing.

[0728] The single-sided coating weight of the negative electrode film is 138 mg / 1540.25 mm. 2 .

[0729] 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 located on the surface of the negative electrode conductive layer, and the second negative electrode film layer is located on the surface of the first negative electrode film layer.

[0730] The first negative electrode film layer comprises graphite particles in a mass ratio of 96.5:0.5:0.5:1.5:1, conductive agent acetylene black, a first lithium-containing binder (lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate copolymer, wherein t...

Claims

1. A charging system, characterized in that, It includes a charging device and an electrical device, wherein the charging device includes an energy storage device; The charging device is configured to determine the charging demand information of the electrical equipment in response to a charging event; Based on the charging demand information, a target charging mode is determined for the charging device to charge the electrical equipment, wherein the target charging mode corresponds to target charging parameters; the charging device includes an energy storage device and a ninth determining module, the ninth determining module being configured to determine whether the energy storage device can charge the electrical equipment with the target charging parameters based on the state of charge value and the remaining energy state value; and to charge the electrical equipment based on the target charging parameters corresponding to the target charging mode; Wherein, when the target charging mode includes a first charging mode, the target charging parameters corresponding to the first charging mode include a first charging parameter, and the charging power indicated by the first charging parameter is greater than 300 kilowatts. The energy storage device includes one or more energy storage units, each energy storage unit having a first positive power supply terminal and a first negative power supply terminal, the one or more energy storage units being connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage device through the first positive power supply terminal and the first negative power supply terminal, and the energy storage device being configured to provide a first direct current. The charging device further includes a charging module and an input module. The charging module is connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage device. The charging module is configured to output charging power based on the first DC power supply. The input module is adapted to provide charging energy to each of the energy storage units. 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. Each of the energy storage units 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. The battery sub-unit includes a single battery cell, the single battery cell includes an electrolyte and a separator, the electrolyte includes an electrolyte salt, the electrolyte salt includes lithium hexafluorophosphate, and the concentration of lithium hexafluorophosphate is in the range of 0.5 mol / L-1.0 mol / L; The single cell includes a negative electrode and a positive electrode. The negative electrode includes a negative current collector and a negative electrode film layer located at least on one side of the negative current collector. The negative electrode film layer includes a negative electrode active material. The positive electrode includes a positive current collector and a positive electrode film layer located at least on one side of the positive current collector. The positive electrode film layer includes a positive electrode active material. When the individual battery cell is 100% charged, the compaction density of the negative electrode film is 1.15 g / cm³. 3 -1.36g / cm 3 The single-sided coating weight of the negative electrode film is 0.09g / 1540.25mm. 2 -0.17g / 1540.25mm 2 The single-sided coating weight of the positive electrode film is 0.2g / 1540.25mm. 2 -0.37g / 1540.25mm 2 The isolation membrane comprises a porous base membrane with a porosity of 20% to 70%.

2. The charging system according to claim 1, characterized in that, The charging device includes a charging control device, the charging control device comprising: The first determining module is configured to determine the charging demand information of the electrical equipment in response to a charging event. The second determining module is configured to determine the target charging mode for the charging device to charge the electrical equipment based on the charging demand information.

3. The charging system according to claim 1, characterized in that, The energy storage device and / or the charging device satisfy one or more of the following conditions: The ratio between the rated energy of the energy storage device and the maximum discharge power of the energy storage device shall not exceed 1:3; The energy storage device has an energy density greater than or equal to 380 Wh / L; The ratio between the rated energy of the energy storage device and the maximum charging power of the charging device is less than 1:

4.

4. The charging system according to claim 1, characterized in that, The ratio between the rated output power of the input module and the rated energy of the battery sub-unit is greater than or equal to 1 / n1, where n1 ranges from 1 to 4.

5. The charging system according to claim 1, characterized in that, 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 ranges from 94% to 99% and n3 ranges from 4 to 6.

6. The charging system according to claim 1, characterized in that, The volumetric energy density of the battery sub-cell is greater than or equal to 380 Wh / L.

7. The charging system according to claim 1, characterized in that, The electrolyte also includes an organic solvent, which includes carbonate solvents.

8. The charging system according to claim 1, characterized in that, The electrolyte salt also includes a fluorosulfonamide salt, the concentration of which is in the range of 0.2 mol / L to 0.5 mol / L.

9. The charging system according to claim 1, characterized in that, The electrolyte also includes an organic solvent, which includes chain-like carboxylic acid ester solvents. Based on the total mass of the solvents, the mass content A of the chain-like carboxylic acid ester solvents satisfies: 5% ≤ A ≤ 75%. The chain-like carboxylic acid ester solvents include compounds with the following structures: Wherein, R1 includes at least one of hydrogen atom, C1-C5 alkyl or C1-C5 haloalkyl, and R2 includes C1-C5 alkyl and / or C1-C5 haloalkyl.

10. The charging system according to claim 9, characterized in that, 40%≤A≤75%。 11. The charging system according to any one of claims 1-10, characterized in that, The negative electrode active material includes a carbon-based material, which includes at least one of natural graphite and artificial graphite.

12. The charging system according to claim 11, characterized in that, The volume average particle size Dv50 of the negative electrode film layer is in the range of 8.2 μm-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 together, the first negative electrode active material layer is located on the side close to the negative electrode current collector, the volume average particle size Dv50 of the negative electrode active material in the first negative electrode active material layer is 9.5 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.

13. The charging system according to claim 1, characterized in that, When the individual battery cell is 100% charged, the compaction density of the positive electrode film is 2.5 g / cm³. 3 -2.8g / cm 3 .

14. The charging system according to claim 1, characterized in that, The thickness of the positive electrode current collector is 10μm-15μm.

15. The charging system according to claim 1, characterized in that, The positive electrode active material includes lithium phosphate; The lithium-containing phosphate comprises phosphate particles and a coating layer, wherein the coating layer covers at least a portion of the surface of the phosphate particles, and the coating layer comprises one or more elements selected from C, Fe, Ti, Zr, Hf, Ge, and Sn.

16. The charging system according to claim 15, characterized in that, The coating layer includes a fast ion conductor, wherein the fast ion conductor comprises a material of the general formula Li. 3-d Fe 2-d M 2d (PO4)3 compounds, M2 including at least one element selected from Ti, Zr, Hf, Ge and Sn, 0≤d≤1.

17. The charging system according to claim 1, characterized in that, The positive electrode further includes a positive conductive layer, which is located between the positive current collector and the positive film layer, and the thickness of the positive conductive layer is in the range of 0.5 μm-2 μm; and / or The negative electrode sheet further includes a negative electrode conductive layer, which 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 0.5μm-2μm.

18. The charging system according to claim 17, characterized in that, The positive electrode conductive layer includes a positive electrode conductive agent, and based on the total mass of the positive electrode conductive layer, the mass content of the positive electrode conductive agent is in the range of 30%-50%; and / or The positive electrode conductive layer includes a positive electrode binder, and the mass content of the positive electrode binder is in the range of 50%-70% based on the total mass of the positive electrode conductive layer.

19. The charging system according to claim 17, characterized in that, The negative electrode conductive layer includes a negative electrode conductive agent, and based on the total mass of the negative electrode conductive layer, the mass content of the negative electrode conductive agent is in the range of 20%-40%; and / or The negative electrode conductive layer includes a negative electrode adhesive, and the mass content of the negative electrode adhesive is in the range of 60%-80% based on the total mass of the negative electrode conductive layer.

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

21. The charging system according to claim 20, characterized in that, Each of the energy storage units is configured to provide a second direct current based on the electrical energy of the battery sub-unit.

22. The charging system according to claim 21, characterized in that, At least some of the energy storage units in the one or more energy storage units further include a first power conversion subunit, which is connected to a first positive power supply terminal and a first negative power supply terminal of the corresponding battery subunit and energy storage unit, respectively, and is configured to convert the electrical energy of the battery subunit into the second direct current. Wherein, if the energy storage unit does not include the first power conversion subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second DC power.

23. The charging system according to claim 22, characterized in that, At least some of the energy storage units in the one or more energy storage units further include a first switching subunit, which is connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding battery subunit and the energy storage unit, respectively, and is configured to connect the corresponding battery subunit to the first positive power supply terminal and the first negative power supply terminal of the energy storage unit when it is turned on, so as to provide the second DC power. Wherein, if the energy storage unit does not include the first switch subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second DC power.

24. The charging system according to claim 23, characterized in that, At least some of the energy storage units in the one or more energy storage units further include a first power conversion subunit and a first switch subunit, wherein the first power conversion subunit and the first switch subunit are connected in series between a first positive power supply terminal and a first negative power supply terminal of the respective battery subunit and energy storage unit, and the first power conversion subunit is configured to convert the electrical energy of the battery subunit into the second DC power when the respective first switch subunit is turned on. Wherein, if the energy storage unit does not include the first power conversion subunit and the first switch subunit, the battery subunit is directly connected to the first positive power supply terminal and the first negative power supply terminal of the corresponding energy storage unit to provide the second DC power.

25. The charging system according to any one of claims 22-24, characterized in that, The input module includes an input interface connected to a second positive power supply terminal and a second negative power supply terminal of the energy storage module, and is configured to provide charging energy to each energy storage unit based on a third DC power supply provided by a first external power supply; or... The input module includes a second power conversion subunit, which is connected to the second positive power supply terminal and the second negative power supply terminal of the energy storage module, and is configured to provide charging energy to each of the energy storage units based on the first AC power provided by the second external power supply.

26. The charging system according to claim 25, characterized in that, The charging module includes a third power conversion subunit and a charging gun. The positive and negative input terminals of the third power conversion subunit are connected to the second positive and second negative power supply terminals of the energy storage module, respectively. The positive and negative output terminals of the third power conversion subunit are connected to the positive and negative input terminals of the charging gun, respectively. The third power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output through the charging gun.

27. The charging system according to claim 25, characterized in that, The charging module includes a fourth power conversion subunit and a charging gun. The positive input terminal of the fourth power conversion subunit is connected to the second positive power supply terminal of the energy storage module, the positive output terminal of the fourth power conversion subunit is connected to the positive input terminal of the charging gun, and the negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The fourth power conversion subunit is configured to convert the first DC power into a fourth DC power and output it through the charging gun.

28. The charging system according to any one of claims 22-24, characterized in that, The energy storage module further includes 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 and connect it to the second positive power supply terminal and the second negative power supply terminal of the energy storage module to provide the first DC power.

29. The charging system according to claim 28, characterized in that, The energy storage module has one second positive power terminal and one second negative power terminal. The selection unit includes multiple second switch sub-units, each of which is connected to one of the energy storage units. Each second switch sub-unit 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 terminals of the one or more energy storage units are respectively connected to the second negative power terminal of the energy storage module. The second switch sub-unit 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 it is turned on.

30. The charging system according to claim 29, characterized in that, The charging module includes a fifth power conversion subunit and a charging gun. The positive and negative input terminals of the fifth power conversion subunit are connected to the second positive and second negative power supply terminals of the energy storage module, respectively. The positive and negative output terminals of the fifth power conversion subunit are connected to the positive and negative input terminals of the charging gun, respectively. The fifth power conversion subunit is configured to convert the first DC power into a fourth DC power for charging output through the charging gun.

31. The charging system according to claim 29, characterized in that, The charging module includes a sixth power conversion subunit and a charging gun. The positive input terminal of the sixth power conversion subunit is connected to the second positive power supply terminal of the energy storage module, the positive output terminal of the sixth power conversion subunit is connected to the positive input terminal of the charging gun, and the negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The sixth power conversion subunit is configured to convert the first DC power into a fourth DC power and output it through the charging gun.

32. The charging system according to claim 31, characterized in that, The energy storage module has multiple second positive power terminals and one second negative power terminal. The selection unit includes multiple second switch sub-units. Each second switch sub-unit is connected to one energy storage unit and one second positive power terminal. Each second switch sub-unit is connected in series between the first positive power terminal and the corresponding second positive power terminal of the energy storage unit. The first negative power terminals of the one or more energy storage units are respectively connected to the second negative power terminal of the energy storage module. The second switch sub-unit is configured to connect the first positive power terminal and the corresponding second positive power terminal of the energy storage unit when it is turned on.

33. The charging system according to claim 32, characterized in that, The charging module includes multiple seventh power conversion sub-units and a charging gun. 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 and output it through the charging gun.

34. The charging system according to claim 32, characterized in that, The charging module includes multiple eighth power conversion sub-units and a charging gun. 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, and the negative input terminal of the charging gun is connected to the second negative power supply terminal of the energy storage module. The multiple eighth power conversion sub-units are configured to convert the first DC power into a fourth DC power and output it through the charging gun.

35. The charging system according to claim 28, characterized in that, The input module includes a ninth power conversion subunit, which is connected to the one or more energy storage units and is configured to provide charging energy to each of the energy storage units based on a first AC power supplied by a second external power source.

36. The charging system according to claim 28, characterized in that, The input module includes multiple tenth power conversion sub-units, each of which is connected to one of the energy storage units. The multiple tenth power conversion sub-units are configured to provide charging energy to each of the energy storage units based on a first AC power supplied by a second external power source.

37. The charging system according to any one of claims 20-24, characterized in that, The charging device further includes a wireless communication module, and at least a portion of the energy storage module, the input module, and the charging module are connected to the wireless communication module to interact with external devices via the wireless communication module.

38. A charging method, applied to the charging system as described in any one of claims 1-37, characterized in that, The charging method includes: In response to charging events, determine the charging demand information of electrical equipment; Based on the charging demand information, a target charging mode is determined for the charging device to charge the electrical equipment, wherein the target charging mode corresponds to target charging parameters; the charging device includes an energy storage device. The electrical equipment is charged based on the target charging parameters corresponding to the target charging mode; Wherein, when the target charging mode includes a first charging mode, the target charging parameters corresponding to the first charging mode include a first charging parameter, and the charging power indicated by the first charging parameter is greater than 300 kilowatts.

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