High-compaction long-cycle-life fast charging battery

Abstract

The utility model provides a high-compaction long-cycle-life fast-charging battery which comprises a shell, a battery pack and a battery pack. The negative electrode plate is arranged in the shell, and the negative electrode plate comprises a negative electrode current collector and a negative electrode active material coated on the surface of the negative electrode current collector; the positive electrode plate is arranged in the shell, and the positive electrode plate comprises a positive electrode current collector and a positive electrode active material coated on the surface of the positive electrode current collector; the diaphragm is arranged between the negative pole piece and the positive pole piece; wherein the negative electrode active material comprises primary granular graphite and secondary granular graphite, the mass of the primary granular graphite and the mass of the secondary granular graphite are in a preset proportion, the primary granular graphite and the secondary granular graphite are respectively made of projectile coke materials, and the particle size of the primary granular graphite is smaller than that of the secondary granular graphite. According to the high-compaction long-cycle-life fast charging battery disclosed by the invention, the compaction density can be increased, so that the fast charging cycle attenuation is slowed down, the cycle life is prolonged, the energy density is increased, and the charging speed is improved.

Description

Technical Field

[0001] This disclosure relates to the field of energy storage technology, and in particular to a high-voltage, long-cycle-life fast-charging battery. Background Technology

[0002] Unlike traditional low-rate batteries, fast-charging cells require the transfer and deintercalation of lithium ions from the positive electrode to the negative electrode in an extremely short time. This process places high demands on the cell system, especially on the negative electrode graphite. On the one hand, graphite needs to have good rate performance to meet the requirement of lithium ion intercalation at high rates. On the other hand, graphite needs to have high cycle stability to ensure the lifespan of the cell.

[0003] In particular, it is difficult for a single graphite particle to meet the performance requirements while also meeting the high-density requirements of the electrode sheet, which affects the battery's cycle life and charging speed, making it difficult to meet energy storage needs. Summary of the Invention

[0004] This disclosure aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, the purpose of this disclosure is to provide a high-voltage, long-cycle-life fast-charging battery.

[0006] To achieve the above objectives, this disclosure provides a high-voltage, long-cycle-life fast-charging battery, comprising: a casing, wherein an electrolyte is disposed within the casing; a negative electrode sheet, wherein the negative electrode sheet is disposed within the casing and comprises: a negative current collector and a negative active material coated on the surface of the negative current collector; a positive electrode sheet, wherein the positive electrode sheet is disposed within the casing and comprises: a positive current collector and a positive active material coated on the surface of the positive current collector; and a separator, wherein the separator is disposed between the negative electrode sheet and the positive electrode sheet; wherein the negative active material comprises: primary granular graphite and secondary granular graphite in a predetermined mass ratio, wherein the primary granular graphite and the secondary granular graphite are respectively made of pellet coke material, and the particle size of the primary particles is smaller than that of the secondary particles.

[0007] Optionally, the mass proportion of the primary particulate graphite in the negative electrode active material ranges from 30% to 70%; and / or, the mass proportion of the secondary particulate graphite in the negative electrode active material ranges from 70% to 30%.

[0008] Optionally, the preset ratio between the mass of the primary graphite particles and the mass of the secondary graphite particles is 5:5.

[0009] Optionally, the primary graphite particles have a particle size range of 9µm-12µm; and / or, the secondary graphite particles have a particle size range of 11µm-16µm.

[0010] Optionally, the compaction range of the primary graphite particles is 1.5 g / cm³. 3 -1.6g / cm 3 ; and / or, the compaction range of the secondary particle graphite is 1.5 g / cm³. 3 -1.6g / cm 3 .

[0011] Optionally, the mass ratio of the negative electrode active material in the negative electrode current collector ranges from 94% to 98%.

[0012] Optionally, the positive electrode active material is lithium iron phosphate, and the particle size range of the positive electrode active material is 0.9 μm-1.5 μm, and the specific surface area of ​​the positive electrode active material is 11 m². 2 / g-16m 2 / g, wherein the mass ratio of the positive electrode active material in the positive electrode current collector ranges from 95% to 98%.

[0013] Optionally, the positive current collector is made of aluminum foil, and the thickness of the aluminum foil is in the range of 12um-15um; and / or, the negative current collector is made of copper foil, and the thickness of the copper foil is in the range of 4um-6um.

[0014] Optionally, the organic solvent in the electrolyte is one or more of ethylene carbonate, methyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, propylene carbonate, and ethyl acetate; the lithium salt in the electrolyte is lithium hexafluorophosphate or lithium bis(fluorosulfonyl)imide; and the additive in the electrolyte is one or more of ethylene carbonate, fluoroethylene carbonate, ethylene sulfate, triphosphate, and methylene disulfonate.

[0015] Optionally, the diaphragm is a high-porous polyethylene ceramic-coated diaphragm.

[0016] The technical solution provided in this disclosure may include the following beneficial effects:

[0017] The negative electrode, positive electrode, and separator are arranged in a casing containing an electrolyte to form the battery structure. With the cooperation of the negative and positive electrodes, the battery can store and release electrical energy. At the same time, since the negative electrode active material is composed of primary and secondary granular graphite in a predetermined mass ratio, the negative electrode can not only combine the advantages of the stable structure and good high-temperature performance of primary granular graphite with the advantages of the good rate performance and low cycle expansion of secondary granular graphite, but also increase the compaction density, thereby slowing down the fast charging cycle decay, extending the cycle life, increasing the energy density, and improving the charging speed.

[0018] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 This is a partial schematic diagram of a high-voltage, long-cycle-life fast-charging battery according to an embodiment of this disclosure;

[0021] Figure 2 This is a schematic diagram of the structure of the negative electrode sheet in a high-voltage, long-cycle-life fast-charging battery according to an embodiment of this disclosure;

[0022] Figure 3 This is a schematic diagram of the structure of the positive electrode in a high-voltage, long-cycle-life fast-charging battery according to an embodiment of this disclosure;

[0023] Figure 4 This is a fast charging cycle capacity retention rate curve proposed in one embodiment of the present disclosure.

[0024] As shown in the figure: 1. Negative electrode sheet, 11. Negative electrode current collector, 12. Negative electrode active material;

[0025] 2. Positive electrode sheet; 21. Positive electrode current collector; 22. Positive electrode active material;

[0026] 3. Diaphragm. Detailed Implementation

[0027] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are used only to explain this disclosure, and should not be construed as limiting this disclosure. Rather, embodiments of this disclosure include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0028] like Figure 1 , Figure 2 and Figure 3As shown in the figure, this disclosure proposes a high-voltage, long-cycle-life fast-charging battery, comprising: a casing (not shown), a negative electrode 1, a positive electrode 2, and a separator 3. An electrolyte is disposed within the casing. The negative electrode 1 is disposed within the casing and includes a negative current collector 11 and a negative active material 12 coated on the surface of the negative current collector 11. The positive electrode 2 is disposed within the casing and includes a positive current collector 21 and a positive active material 22 coated on the surface of the positive current collector 21. The separator 3 is disposed between the negative electrode 1 and the positive electrode 2. The negative active material 12 comprises primary granular graphite and secondary granular graphite in a predetermined mass ratio. The primary and secondary granular graphite are respectively made of pellet coke material, and the particle size of the primary particles is smaller than that of the secondary particles.

[0029] It is understandable that the negative electrode 1, positive electrode 2, and separator 3 are arranged in a shell containing electrolyte to form a battery structure. Thus, with the cooperation of the negative electrode 1 and positive electrode 2, the battery can store and release electrical energy. At the same time, since the negative electrode active material 12 of the negative electrode 1 is composed of primary granular graphite and secondary granular graphite in a predetermined mass ratio, the negative electrode 1 can not only take into account the advantages of the stable structure and good high-temperature performance of primary granular graphite and the advantages of the good rate performance and low cycle expansion of secondary granular graphite, but also increase the compaction density, thereby slowing down the fast charging cycle decay, extending the cycle life, increasing the energy density, and improving the charging speed.

[0030] It should be noted that the mainstream fast-charging anode material currently on the market is artificial graphite made from needle coke, but its high price has always been one of the important factors limiting its development. Shot coke, as a new type of low-temperature carbonized deposited coal product, has the characteristics of low cost, high conductivity and stability, making it very suitable as a raw material for fast-charging artificial graphite.

[0031] Based on different synthesis processes, graphite made from pellet coke can be divided into two main categories: primary particle graphite and secondary particle graphite. Primary particle graphite is characterized by structural stability and good high-temperature performance, while secondary particle graphite is characterized by good rate performance and low cyclic expansion.

[0032] For fast-charging batteries, on the one hand, using only secondary graphite particles will result in significant high-temperature losses in the cell and rapid capacity decay during cycles. On the other hand, using only primary graphite particles will result in the system's rate performance not meeting requirements, leading to the risk of lithium plating during cycles. Furthermore, it is difficult for single graphite particles to meet both performance requirements and the need for high electrode compaction.

[0033] In summary, mixing primary and secondary granular graphite synthesized from pellet coke in a predetermined ratio can combine the advantages of both, meet rate performance requirements, slow down fast charging cycle degradation, and increase the compaction density of the negative electrode, enabling the battery cell to achieve higher energy density.

[0034] The fast-charging battery of this embodiment optimizes the type of coke raw materials and graphite combination, while improving the compaction of the negative electrode artificial graphite sheet and increasing the cycle life and charging speed of the cell. It not only has the performance of high compaction, long cycle life and fast charging, but also has good chemical and safety performance. The manufacturing process is simple and the cost is low, making it suitable for large-scale commercial production.

[0035] The negative electrode active material 12 is composed of primary granular graphite and secondary granular graphite mixed in a predetermined mass ratio. The primary granular graphite and secondary granular graphite are made of shot coke material, which not only has low raw material cost and simple manufacturing process, making it suitable for large-scale commercialization, but also has advantages such as high pressure and long cycle life, fast charging and stable electrochemical performance.

[0036] The synthesis route for primary particulate graphite is: pellet coke (raw material) - crushing and shaping - graphitization; the synthesis route for secondary particulate graphite is: pellet coke (raw material) - crushing and shaping - graphitization - granulation - coating carbonization - crushing.

[0037] The casing, as the main structure of the battery, is used to house the electrolyte and the negative electrode 1, positive electrode 2, and separator 3 immersed in the electrolyte. The specific type of casing can be set according to actual needs and there are no restrictions on it.

[0038] Electrolytes are used to provide a medium for ion transport, thereby enabling the charging and discharging process of the battery. The specific type of electrolyte can be set according to actual needs and there are no restrictions on it.

[0039] The negative electrode 1 is responsible for storing and releasing ions, providing an electron transport path, and affecting the battery's energy density, cycle life, and rate performance. The specific type of negative electrode 1 can be set according to actual needs and is not limited thereto.

[0040] The positive electrode 2 is responsible for storing and releasing ions, providing an electron transport path, and affecting the battery's energy density, voltage plateau, and thermal stability. The specific type of the positive electrode 2 can be set according to actual needs and is not restricted.

[0041] The separator 3 physically isolates the negative electrode 1 and the positive electrode 2, ensuring ion conduction, providing thermal stability and mechanical strength, and ensuring the safety and performance of the battery. The specific type of separator 3 can be set according to actual needs and there are no restrictions on it.

[0042] The arrangement of the negative electrode 1 and the positive electrode 2 can be set according to actual needs, and there are no restrictions on it. For example, the negative electrode 1 and the positive electrode 2 can adopt a stacked structure or a wound structure.

[0043] In some embodiments, the mass ratio of primary particulate graphite in the negative electrode active material 12 ranges from 30% to 70%; and / or, the mass ratio of secondary particulate graphite in the negative electrode active material 12 ranges from 70% to 30%.

[0044] Understandably, since the mass ratio of primary granular graphite in the negative electrode active material 12 ranges from 30% to 70%, and the mass ratio of secondary granular graphite in the negative electrode active material 12 ranges from 70% to 30%, the negative electrode active material 12 of the negative electrode sheet 1 can be made of a mixture of primary granular graphite and secondary granular graphite, and the mass ratio of primary granular graphite to secondary granular graphite ranges from 3:7 to 7:3. This allows the negative electrode sheet 1 to not only take into account the advantages of primary granular graphite in terms of structural stability and high-temperature performance, as well as the advantages of secondary granular graphite in terms of good rate performance and low cycle expansion, but also to increase the compaction density, thereby slowing down fast charging cycle decay, extending cycle life, increasing energy density, and improving charging speed.

[0045] The mass ratio of primary graphite particles in the negative electrode active material 12 can be 30%, 40%, 55%, 60%, 70%, etc., and there is no limitation on this.

[0046] The mass ratio of secondary particulate graphite in the negative electrode active material 12 can be 30%, 40%, 50%, 60%, 70%, etc., and there is no restriction on this.

[0047] It should be noted that since the negative electrode active material 12 is composed of primary and secondary granular graphite, when the mass ratio of primary granular graphite in the negative electrode active material 12 increases, the mass ratio of secondary granular graphite in the negative electrode active material 12 decreases accordingly. Conversely, when the mass ratio of primary granular graphite in the negative electrode active material 12 decreases, the mass ratio of secondary granular graphite in the negative electrode active material 12 increases accordingly.

[0048] For example, when the mass ratio of primary graphite particles in the negative electrode active material 12 is 40%, the mass ratio of secondary graphite particles in the negative electrode active material 12 is 60%; when the mass ratio of primary graphite particles in the negative electrode active material 12 is 70%, the mass ratio of secondary graphite particles in the negative electrode active material 12 is 30%.

[0049] In some embodiments, the preset ratio between the mass of primary graphite particles and the mass of secondary graphite particles is 5:5.

[0050] Understandably, since the preset ratio between the mass of primary granular graphite and the mass of secondary granular graphite is 5:5, the negative electrode active material 12 of the negative electrode sheet 1 can efficiently combine the advantages of the stable structure and good high-temperature performance of primary granular graphite with the advantages of the good rate performance and low cycle expansion of secondary granular graphite. Moreover, it can significantly increase the compaction density, thereby slowing down the fast charging cycle decay, extending the cycle life, increasing the energy density, and improving the charging speed.

[0051] It should be noted that 5:5 is the preferred mass ratio between primary and secondary graphite particles in this embodiment. For different application scenarios, other ratios can be used between the mass of primary and secondary graphite particles, and there are no restrictions on this.

[0052] In some embodiments, the particle size range of primary graphite particles is 9µm-12µm; and / or, the particle size range of secondary graphite particles is 11µm-16µm.

[0053] It is understandable that primary graphite particles with a particle size range of 9um-12um and secondary graphite particles with a particle size range of 11um-16um are mixed to form the negative electrode active material 12 of the negative electrode sheet 1, thereby giving the negative electrode sheet 1 a higher compaction density, thus extending the cycle life and improving the charging speed.

[0054] It should be noted that the particle size of primary graphite can be 9um, 10um, 10.5um, 11um, 12um, etc., and there is no limitation on this.

[0055] The particle size of secondary particulate graphite can be 11um, 12um, 13um, 14um, 15um, 16um, etc., and there is no restriction on this.

[0056] The aggregate particle size range of secondary granular graphite can be 7um-9um, and further, the aggregate particle size of secondary granular graphite can be 7um, 8um, 8.3um, or 9um.

[0057] In some embodiments, the compaction range of primary graphite particles is 1.5 g / cm³. 3 -1.6g / cm 3 ; and / or, the compaction range of secondary graphite particles is 1.5 g / cm³. 3 -1.6g / cm 3 .

[0058] It is understandable that the compaction range of primary and secondary graphite particles is 1.5 g / cm³. 3 -1.6g / cm 3This results in the negative electrode 1 having a higher compaction density, thereby extending cycle life and increasing charging speed.

[0059] It should be noted that the compacted density of primary and secondary graphite particles can be 1.5 g / cm³. 3 1.51g / cm 3 1.54g / cm 3 1.58g / cm 3 1.6g / cm 3 There are no restrictions on this.

[0060] The residual carbon content of secondary particulate graphite can range from 1.5% to 4.5%. Specifically, the residual carbon content of secondary particulate graphite can be 1.5%, 3%, 3.5%, 4%, 4.5%, etc., and there is no limit to this.

[0061] In some embodiments, the mass ratio of the negative electrode active material 12 in the negative electrode current collector 11 ranges from 94% to 98%.

[0062] It is understandable that the mass ratio of the negative electrode active material 12 in the negative electrode current collector 11 ranges from 94% to 98%, which makes the negative electrode 1 have a longer cycle life and a higher charging speed.

[0063] It should be noted that the mass ratio of the negative electrode active material 12 in the negative electrode current collector 11 can be 94%, 95%, 96%, 97%, 98%, etc., and there is no limitation thereto.

[0064] The slurry of the negative electrode active material 12 is made by first mixing secondary particles and primary particle dry powder in a certain mass ratio, then adding dispersant, binder, conductive agent and solvent and dispersing at high speed to obtain a uniformly dispersed slurry with a solid content of 50%-56% and a viscosity of 2000-5000.

[0065] In some embodiments, the positive electrode active material 22 is lithium iron phosphate, and the particle size range of the positive electrode active material 22 is 0.9 μm-1.5 μm, and the specific surface area of ​​the positive electrode active material 22 is 11 m². 2 / g-16m 2 / g, the mass ratio of positive electrode active material 22 in positive electrode current collector 21 ranges from 95% to 98%.

[0066] It is understandable that, since the positive electrode active material 22 is lithium iron phosphate, and the particle size range of the positive electrode active material 22 is 0.9um-1.5um, the specific surface area of ​​the positive electrode active material 22 is 11m². 2 / g-16m 2 / g, the mass ratio of positive electrode active material 22 in positive electrode current collector 21 ranges from 95% to 98%, which makes the battery have higher energy density, cycle performance, rate performance and safety, while reducing cost.

[0067] It should be noted that the particle size of the positive electrode active material 22 can be 0.9um, 1um, 1.1um, 1.3um, 1.5um, etc., and there is no limitation on it.

[0068] The specific surface area of ​​the positive electrode active material 22 can be 11 m². 2 / g、12m 2 / g、14m 2 / g, 15m 2 / g, 16m 2 / g, etc., are not restricted in this regard.

[0069] The mass ratio of the positive electrode active material 22 in the positive electrode current collector 21 can be 95%, 96%, 97%, 98%, etc., and there is no limitation thereto.

[0070] In some embodiments, the positive current collector 21 is made of aluminum foil, and the thickness of the aluminum foil ranges from 12um to 15um; and / or, the negative current collector 11 is made of copper foil, and the thickness of the copper foil ranges from 4um to 6um.

[0071] It is understandable that the positive electrode current collector 21 uses aluminum foil with a thickness ranging from 12um to 15um, and the negative electrode current collector uses copper foil with a thickness ranging from 4um to 6um, which enables the battery to have higher energy density, cycle life, rate performance, safety and cost-effectiveness.

[0072] In some embodiments, the organic solvent in the electrolyte is one or more of ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), propylene carbonate (PC), and ethyl acetate (EA); the lithium salt in the electrolyte is lithium hexafluorophosphate (LiPF6) or lithium bis(fluorosulfonyl)imide (LiFSi); and the additive in the electrolyte is one or more of ethylene carbonate (VC), fluoroethylene carbonate (FEC), ethylene sulfate (DTD), triphosphate (TMSP), and methylene disulfonate (MMDS).

[0073] In some embodiments, the diaphragm 3 is a high-porous polyethylene (PE) ceramic-coated diaphragm 3.

[0074] It should be noted that the high-porosity polyethylene ceramic-coated separator 3 is a high-performance battery separator 3 material that combines the excellent properties of polyethylene substrate with the functional advantages of ceramic coating and adhesive layer, which can significantly improve the safety, performance and economy of battery.

[0075] Based on the battery in this embodiment, a wound structure was used to prepare five sets of samples for analysis:

[0076] The negative electrode active material 12 and the positive electrode active material 22 are respectively processed into electrode sheets of a specified size through homogenization, coating, rolling, and slitting processes. Then, they are manufactured into square aluminum-cased batteries through winding, assembly, electrolyte injection, and formation processes. Cyclic testing is conducted under high-rate charge-discharge conditions of 2.5C / 1C at 25℃, with the cell capacity retention rate decaying to 80% of the initial state of charge (SOC) as the cutoff condition. Cyclic data are recorded on [the relevant data]. Figure 4 And in the table below.

[0077] All samples in all groups used a negative electrode plate with a strength of 1.65 g / cm³. 3 The electrode sheets are compacted by roller pressing.

[0078] Except for the different ratio of primary to secondary particles in negative electrode plate 1, all other materials of samples 1-5 adopt the same design and manufacturing process.

[0079] Among them, the negative electrode of sample 1 is pure primary particles; the negative electrode of sample 2 is primary particles: secondary particles = 7:3; the negative electrode of sample 3 is primary particles: secondary particles = 5:5; the negative electrode of sample 4 is primary particles: secondary particles = 3:7; and sample 5 is pure secondary particles.

[0080] Experiment number Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Primary granules: Secondary granules 10：0 7：3 5：5 3：7 0：10 80% of EOL cycle count 1261 2029 2693 2337 1505

[0081] The table shows the number of cycles at 25℃ 2.5C / 1C fast charging to 80% EOL for different graphite ratios.

[0082] from Figure 4 As can be seen from the table above, the negative electrode active material composed of primary and secondary granular graphite has a longer cycle life and a higher charging speed, especially when the mass ratio of primary to secondary granular graphite is 5:5.

[0083] The fast-charging battery in this embodiment, through optimizing the combination of raw materials and graphite, explores and obtains a fast-charging cycle negative electrode system with lower cost and better cycle performance.

[0084] It should be noted that in the description of this disclosure, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0085] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of preferred embodiments of this disclosure includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this disclosure pertain.

[0086] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0087] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A high-voltage, long-cycle-life fast-charging battery, characterized in that, include: A housing containing an electrolyte; A negative electrode sheet is disposed within the housing, and the negative electrode sheet includes: a negative current collector and a negative active material coated on the surface of the negative current collector; A positive electrode sheet is disposed within the housing, and the positive electrode sheet includes: a positive current collector and a positive active material coated on the surface of the positive current collector; A separator is disposed between the negative electrode and the positive electrode. The negative electrode active material includes primary granular graphite and secondary granular graphite in a predetermined mass ratio. The primary granular graphite and the secondary granular graphite are respectively made of shot coke material, and the particle size of the primary particles is smaller than that of the secondary particles.

2. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The mass proportion of the primary particulate graphite in the negative electrode active material ranges from 30% to 70%. And / or, The secondary particulate graphite in the negative electrode active material has a mass ratio ranging from 70% to 30%.

3. The high-voltage, long-cycle-life fast-charging battery according to claim 2, characterized in that, The preset ratio between the mass of the primary graphite particles and the mass of the secondary graphite particles is 5:

5.

4. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The particle size range of the primary graphite particles is 9µm-12µm; And / or, The particle size range of the secondary graphite particles is 11um-16um.

5. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The compaction range of the primary graphite particles is 1.5 g / cm³. 3 -1.6g / cm 3 ; And / or, The compaction range of the secondary granular graphite is 1.5 g / cm³. 3 -1.6g / cm 3 .

6. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The mass ratio of the negative electrode active material in the negative electrode current collector ranges from 94% to 98%.

7. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The positive electrode active material is lithium iron phosphate, and the particle size range of the positive electrode active material is 0.9 μm-1.5 μm, and the specific surface area of ​​the positive electrode active material is 11 m². 2 / g-16m 2 / g, wherein the mass ratio of the positive electrode active material in the positive electrode current collector ranges from 95% to 98%.

8. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The positive current collector is made of aluminum foil, and the thickness of the aluminum foil ranges from 12um to 15um; And / or, The negative electrode current collector is made of copper foil, and the thickness of the copper foil ranges from 4um to 6um.

9. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The organic solvent in the electrolyte is one or more of ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, propylene carbonate, and ethyl acetate. The lithium salt in the electrolyte is lithium hexafluorophosphate or lithium difluorosulfonylimide; The additives in the electrolyte are one or more of vinylene carbonate, fluoroethylene carbonate, vinyl sulfate, triphosphate, and methylene disulfonate.

10. The high-voltage, long-cycle-life fast-charging battery according to claim 1, characterized in that, The diaphragm is a high-porous polyethylene ceramic-coated diaphragm.

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