Preparation method of high-voltage lithium ion fast-charging battery

Abstract

The application provides a preparation method of a high-voltage lithium ion fast-charging battery. Through the step distribution of the active material particle size of the pole piece and a two-step liquid injection and formation process, the battery impedance under the fast-charging effect of the high-energy-density battery is effectively reduced, and the cycle stability, high-temperature storage performance and rate performance of the battery under the high-voltage condition are improved. Through optimization of the particle size control range of the step distribution, the influence of the particle size change on the secondary liquid injection process condition is explored and revealed, and the control condition of the secondary liquid injection under different particle size distribution conditions is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery manufacturing, in particular to a preparation method of high-voltage lithium ion fast-charging battery. BACKGROUND

[0002] Lithium ion batteries have been widely used in the current market, with the acceleration of people's life pace and the rapid response requirements in special fields, the requirements for the convenience and efficiency of various products are also gradually deepening, so the energy density and fast-charging performance of lithium ion batteries are also put forward higher demand. Increasing the charging voltage of the battery is an important means to improve the energy density of the battery, which can effectively reduce the charging frequency of electric tools, mobile power supplies and the like, and improve the service life of the battery; at the same time, fast charging can further improve the use experience, especially 3C series products have been more and more favored by the market.

[0003] But the high-energy-density fast-charging battery has great defects in performance stability, cycle life and safety, etc. On the one hand, during fast charging, the migration rate of lithium ions inside the electrode particles is less than the rate of the electrochemical reaction occurring on the surface, so it will cause the concentration polarization phenomenon of the electrode, making the positive and negative electrode potential difference deviate from the equilibrium potential, and the solid electrolyte interface film (SEI film) will start to break down under large current, then the electrode material and electrolyte will react, the electrode material will be damaged, resulting in electrolyte capacity attenuation and electrolyte decomposition gas, etc. Continuous fast charging will also exacerbate the rapid increase of the above adverse reactions. On the other hand, the heat generated by fast charging and the uneven heat will become a potential cause of battery thermal runaway (Thermal Runaway). Generally, the battery has a very high thermal runaway temperature threshold, but fast charging will bring greater lithium precipitation effect, and the tree-like structure of lithium dendrites will greatly reduce the critical temperature of the battery, thereby increasing the risk of thermal runaway. That is, the thermal effect during fast charging increases the battery temperature, and the lithium precipitation effect reduces the critical temperature, and the two negative effects superimpose to exacerbate the risk of thermal runaway. SUMMARY

[0004] The present application provides a preparation method of high-voltage lithium ion fast-charging battery, which improves the fast-charging, cycle and high-temperature storage performance of the battery while solving the problems of insufficient life and safety stability of high-energy-density battery under fast-charging demand in the prior art.

[0005] Specifically, the preparation method of high-voltage lithium ion fast-charging battery provided by the present application adopts a step distribution of the particle size of the negative electrode sheet active material, and the electrolyte is formed by two-step liquid injection.

[0006] As an optional optimization scheme, the step distribution design of the negative electrode sheet is two layers, and the active material particle size D50 decreases from the current collector outward.

[0007] As an optional optimization, the inner layer active material particle size D50 near the current collector is 10-30 μm.

[0008] As an optional optimization, the outer layer active material particle size D50 is 6-13 μm.

[0009] As an optional optimization, the thickness of the outer layer active material is 0.2%-20% of the total thickness of the outer layer active material and the inner layer active material, and more preferably 5%-12%.

[0010] As an optional optimization, the thickness of the outer layer active material is 8-30 μm.

[0011] As an optional optimization, the battery voltage is greater than 4.35 V, the first formation cutoff voltage is 3.5-3.8 V, and the second formation cutoff voltage is > 3.8 V.

[0012] As an optional optimization, the first injection of electrolyte is generally 60%-80% of the total injection amount, and the second injection is the remainder.

[0013] As an optional optimization, when the outer layer active material particle size D50 is 6-10 μm, the first injection amount is 70%-80% of the total injection amount, and the first formation cutoff voltage is 3.5-3.7 V; when the outer layer active material particle size D50 is 11-13 μm, the first injection amount is 60%-70% of the total injection amount, and the first formation cutoff voltage is 3.7-3.8 V.

[0014] As an optional optimization, the second injection of electrolyte is supplemented with an additive for positive electrode film formation alone or a high-impedance positive and negative electrode film formation additive, including at least one of phosphoric acid ester, nitrile, alkenyl-, alkynyl-, or cyano-containing compounds, and the like, with a tri-nitrile additive being preferred.

[0015] As an optional optimization, the percentage of the second injection of the supplemental additive in the total amount of electrolyte is: nitrile: 0.5%-6% of the single nitrile based on the multiple nitrile groups contained, preferably (3±0.6)%; phosphoric acid ester: 0.1%-1%, preferably (0.5±0.1)%; alkenyl-containing silane: 0.1%-0.5%, preferably (0.3±0.1) %.

[0016] As an optional solution of optimization, the electrolyte added in one-time injection is added with low-impedance positive and negative electrode film-forming additives or negative electrode film-forming additives, which include at least one of 0-2% propylene carbonate, 0-20% fluoroethylene carbonate, 0-2% vinyl sulfate, 0-8% 1,3 propane sulfone lactone, 0-1% 1,3 propylene sulfone lactone, 0-5% lithium difluorophosphate, 0-3% lithium difluoro oxalate borate, 0-2% lithium bisoxalate borate, 0-3% lithium tetrafluoroborate, 0-2% 1,3 dioxane, 0-2% 1,4 dioxane, 0-5% lithium bisfluorosulfonimide, 0-5% lithium bis-trifluoromethyl sulfonamide, in terms of mass percentage and the lower limit is not 0.

[0017] As an optional solution of optimization, the positive electrode active material of the lithium ion fast-charging battery is at least one of a transition metal composite lithium oxide or a transition metal phosphate compound, and the chemical formulas of the transition metal composite oxide and the transition metal phosphate compound are respectively Li x M1O2, Li y M2PO4, xLi2MnO3·(1-x)LiM3O2, Li z (M4)2O4, wherein M1, M2, M3, and M4 respectively represent one or more transition metal elements, 0.05≤x≤1.20, 0.05≤y≤1.20, and 0.05≤z≤1.20; and the negative electrode active material is at least one of natural graphite, artificial graphite, mesophase carbon microbeads, hard carbon, soft carbon, silicon (oxygen), silicon (oxygen)-carbon composite, Li-Sn alloy, Li-Ge alloy, Li-Sn-O alloy, Sn, SnO, SnO2, spinel-structured lithiated TiO2-Li4Ti5O 12 12, MXene.

[0018] The present application effectively reduces the battery impedance under the fast-charging action of high-energy-density batteries and improves the cycle stability, high-temperature storage performance and rate performance under high-voltage conditions of the batteries by means of the two-step liquid injection chemical formation process of the step distribution of the active material particle size of the pole piece. Further, by optimizing the particle size control range of the step distribution, the influence of the particle size change on the secondary injection process conditions is explored and revealed, and the control conditions of the secondary injection under different particle size distribution conditions are obtained, so that the comprehensive performance of the high-voltage fast-charging battery reaches the optimal design goal. It has important fast-charging market application value. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of the present application, the present application will be described more fully below, and the preferred embodiments of the present application will be given. However, it should be understood that these embodiments are only used for more detailed description, and should not be understood as limiting the present application in any form, i.e. not intended to limit the protection scope of the present application.

[0020] The application provides a preparation method of a high-voltage lithium ion fast-charging battery.

[0021] To achieve the effect of optimizing the design of the particle size of the negative electrode active material, the particle D50 of the active material decreases from the current collector. With the decrease of the particle size, the close packing between particles is enhanced, the contact density is increased, and the specific surface area is increased, which is beneficial to the increase of capacity, but the crystallization degree of the particles is reduced, which will lose part of the capacity density, therefore, the effective balance between the positive influence of capacity caused by the particle packing contact and the negative influence of capacity caused by the particle crystallization needs to be considered, and at the same time, the outer particles are directly in contact with the electrolyte, the prevention of the too close packing of the particles to affect the wettability needs to be considered while reducing the D50. Therefore, the step distribution design of the negative electrode plate is designed as two layers, the particle size D50 of the inner layer active material close to the current collector is 15-30 mu m, and the particle size D50 of the outer layer active material is 6-13 mu m.

[0022] The outer layer active material on the negative electrode plate plays a spacing role between the inner layer active material and the electrolyte, and plays a leading role in the wettability of the plate, interface generation and lithium extraction, and the range of the particle size of the outer layer active material plays a decisive role. In the above design of the particle size D50 of the outer layer active material, it is found that the specific surface area of the particle size below 6 mu m is too large, the side reaction is too much, which is not conducive to the improvement of the service life and energy density of the battery, and the particle size above 13 mu m is difficult for lithium ion extraction, which is not conducive to the improvement of the fast-charging performance. As a further optimization, we selected the particle size D50 of the outer layer active material as 8-11 mu m in the experiment, and obtained better comprehensive performance indicators.

[0023] Since the reduction of the particle size of the outer layer active material on the negative electrode plate will cause more loss of energy density, we further control the thickness, the thickness of the outer layer active material is generally less than that of the inner layer active material, and the thickness of the outer layer active material accounts for 0.2-20% of the total thickness of the outer layer active material and the inner layer active material, and the thickness of the outer layer active material is 8-30 mu m in terms of thickness size, which can ensure a high energy density and avoid lithium deposition caused by the thin outer layer, thereby reducing the battery life. As a further optimization, we selected the thickness of the outer layer active material to account for 5-12% of the total thickness of the outer layer active material and the inner layer active material in the experiment, and obtained better comprehensive performance indicators.

[0024] The step distribution of the particle size of the negative active material provides a basis for high energy density and a certain guarantee for safety. The high voltage required at high energy density needs to be greater than 4.35 V. In order to match the smaller particle size ratio of the outer active material, the voltage of the first formation in the two-step injection needs to be appropriately controlled at a higher level, but at the same time, the stability of the electrolyte needs to be ensured. In order to form a better interface film, the experiment controls the first formation cut-off voltage to be 3.5-3.8 V, and the second formation cut-off voltage is greater than 3.8 V.

[0025] In order to fully soak and react the electrolyte of the two-step injection, the electrolyte of the first injection is generally 60% to 80% of the total injection amount, and the second injection is the remaining amount.

[0026] In order to further optimize the comprehensive performance of the obtained battery, the influence of the step distribution of the particle size of the negative active material on the two-step injection condition is further optimized and analyzed. It is found that the first injection amount decreases with the increase of the D50 of the outer active material particles and the decrease of the thickness. It is shown that within the particle size range of the outer active material corresponding to the high energy density of the present application, the smaller the D50, the thicker the outer layer, the larger the specific surface area of the pole piece, the more additives needed for film formation, and the increase of the first injection amount is beneficial to the full film formation and inhibition of the side effects of the second injection additives on the negative electrode. At the same time, the first formation cut-off voltage decreases with the decrease of the outer layer D50 and the increase of the outer layer thickness. It is shown that within the particle size range of the outer active material corresponding to the high energy density of the present application, on the one hand, the decrease of D50 and the increase of the outer layer thickness are beneficial to the electrolyte soaking, and the polarization generated in the formation process is small, so that a better protection film can be formed at a lower voltage. On the other hand, under the condition of D50 reduction and outer layer thickness increase, the first injection amount is usually larger, and a better protection film can be formed at a lower voltage. Therefore, as a further optimization, when the particle size D50 of the outer active material is 6-10 μm, the first injection amount is 70% to 80% of the total injection amount, and the first formation cut-off voltage is 3.5-3.7 V; when the particle size D50 of the outer active material is 11-13 μm, the first injection amount is 60% to 70% of the total injection amount, and the first formation cut-off voltage is 3.7-3.8 V. Among them, the first injection amount of 70% and the first formation cut-off voltage of 3.7 V serve as a critical point, which can be divided into one of the two particle size ranges of D50.

[0027] To promote good formation of the interface film, electrolyte additives can be added in the two-step liquid injection. The electrolyte of the first liquid injection can add low impedance positive and negative film-forming additives or negative film-forming additives, including but not limited to: at least one of propylene carbonate (0-2%), fluoroethylene carbonate (0-20%), vinyl sulfate (0-2%), 1,3 propane sulfone lactone (0-8%), 1,3 propylene sulfone lactone (0-1%), lithium difluorophosphate (0-5%), lithium difluoro oxalate borate (0-3%), lithium bisoxalate borate (0-2%), lithium tetrafluoroborate (0-3%), 1,3 dioxane (0-2%), 1,4 dioxane (0-2%), lithium bisfluorosulfonylimide (0-5%), lithium bis-trifluoromethyl sulfonamide imide (0-5%), all in the form of the percentage of the total mass of the electrolyte, and the lower limit is not 0. The electrolyte of the second liquid injection can supplement the addition of single positive film-forming additives or high impedance positive and negative film-forming additives, including but not limited to: at least one of phosphate esters, nitriles, compounds containing alkenyl, alkynyl or cyano, etc., with trinitrile additives being preferred.

[0028] The formation procedure of the second liquid injection requires a more severe condition environment, which needs to be carried out at a higher voltage and with less residual electrolyte, so the content of the additive needs to be further optimized and controlled to avoid the insufficient additive affecting the film formation while also avoiding the excessive additive causing adverse side reactions. We found that different types of additives have different optimized control addition ranges. The percentage of the supplementary additive in the total electrolyte is: 0.5%-6% for nitrile groups, preferably (3±0.6)%, for nitrile groups in nitrile compounds; 0.1%-1% for phosphate esters, preferably (0.5±0.1)%; and 0.1%-0.5% for alkenyl-containing silanes, preferably (0.3±0.1)%.

[0029] The battery prepared by the above method includes a positive electrode sheet containing a positive electrode active material, the above-mentioned negative electrode sheet containing a negative electrode active material, a separator, and the above-mentioned electrolyte.

[0030] The positive electrode active material includes one or more positive electrode active substances capable of deintercalating lithium ions, a positive electrode binder, and a positive electrode conductive agent, the positive electrode active substance being at least one of a transition metal composite lithium oxide or a transition metal phosphate compound, the chemical formula of the transition metal composite oxide or the transition metal phosphate compound being Li x M1O2, Li y M2PO4, xLi2MnO3·(1-x)LiM3O2, Li z (M4)2O4, wherein M1, M2, M3, and M4 represent one or more transition metal elements, 0.05≤x≤1.20, 0.05≤y≤1.20, and 0.05≤z≤1.20.

[0031] The transition metal composite oxide, the transition metal phosphate compound can contain a doping element selected from one or more of Al, Co, Mg, Ta, W, Nb, Zr, Ca, V, Mo, Cr, La, Sc, Lu, Y, and B.

[0032] The positive electrode conductive agent is a carbon material, a metal material, or a conductive polymer.

[0033] The negative electrode active material is at least one of natural graphite, artificial graphite, meso-carbon microbead, hard carbon, soft carbon, silicon (oxide), silicon (oxide)-carbon composite, Li-Sn alloy, Li-Ge alloy, Li-Sn-O alloy, Sn, SnO, SnO2, spinel-structured lithiated TiO2-Li4Ti5O 12 , and MXene.

[0034] Optionally, the compound has a coating on the surface thereof, or can be mixed with another compound having a coating.

[0035] Optionally, the coating is at least one coating element compound of an oxide of a coating element, a hydroxide of a coating element, a hydroxyl oxide of a coating element, a carbonate or nitrate or phosphate or borate of a coating element, or a hydroxyl carbonate of a coating element.

[0036] Optionally, the coating element compound is amorphous or crystalline.

[0037] Optionally, the coating element is Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, Ta, Nb, La, or a mixture thereof.

[0038] The separator film is at least one of polyethylene, polypropylene, polyethylene terephthalate, polyimide, and aramid.

[0039] Optionally, the separator film includes a porous layer disposed on at least one surface of the separator film.

[0040] Optionally, the porous layer includes inorganic particles and a binder.

[0041] Optionally, the inorganic particles are at least one of alumina, silica, magnesia, titania, hafnia, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconia, yttria, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate.

[0042] The binder is at least one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, carboxymethyl cellulose, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.

[0043] To further verify the above scheme of the present application, a series of examples are prepared below for comparative analysis.

[0044] 1. Preparation of lithium ion battery

[0045] The positive active material lithium cobalt oxide (LCO) (or lithium nickel cobalt manganese oxide (NCM523)), conductive agent Super P, polyvinylidene fluoride (PVDF), carbon nanotubes are mixed in a weight ratio of 95:2:2.5:0.5, N-methyl pyrrolidone (NMP) is added, and the mixture is stirred uniformly under the action of a vacuum stirrer to obtain a positive electrode slurry, wherein the solid content of the positive electrode slurry is 70wt%. The obtained positive electrode slurry is uniformly coated on the positive electrode current collector aluminum foil, the aluminum foil coated with the positive electrode slurry is dried at 90°C, and then after cold pressing, cutting and slitting, a positive electrode sheet is obtained.

[0046] The negative active material graphite 1, conductive additive Super P, sodium carboxymethyl cellulose (CMC), binder styrene-butadiene rubber (SBR), carbon nanotubes are mixed in a weight ratio of 95:1.5:1.4:1.6:0.5, deionized water is added, and a negative electrode slurry 1 is obtained under the action of a vacuum stirrer, wherein the solid content of the negative electrode slurry is 50wt%; in the same way, the active material graphite 2 and the conductive agent, the binder, etc. are mixed in the same proportion, deionized water is added, and the slurry 2 is prepared by vacuum stirring; the negative electrode slurry 1 and the negative electrode slurry 2 are uniformly coated on the negative electrode current collector copper foil by the method of extrusion coating with the slurry 1 nozzle below the slurry 2 nozzle; the copper foil is dried at 80°C, and then after cold pressing, cutting and slitting, it is dried at 110°C under vacuum conditions for 12h to obtain a negative electrode sheet. Among them, the negative active material graphite 1 and the active material graphite 2 use different graphite particle sizes.

[0047] In a dry argon atmosphere glove box, ethylene carbonate, propylene carbonate, propyl propionate, ethyl propionate, dimethyl carbonate are mixed in a ratio of 1:1:1:1:1, 0.5% vinyl sulfate, 4% fluoroethylene carbonate are dissolved and stirred thoroughly, then 1.1M LiPF6 is added, and the mixture is stirred uniformly to obtain electrolyte 1, and electrolyte 2 is obtained by adding a proper amount of positive electrode film-forming additive to electrolyte 1.

[0048] The separator film is a 16μm thick polyethylene (PE) separator film.

[0049] The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order with the separator between the positive and negative electrode sheets to play a role of separation, and after the tab is welded, the lithium ion battery is obtained by placing in an outer packaging aluminum plastic film, drying, injecting the prepared electrolyte 1, vacuum packaging, standing, injecting electrolyte 2 after primary formation, shaping, capacity test, and the like after secondary formation.

[0050] 2. Test method

[0051] (1) Test of cycle performance of lithium ion battery

[0052] The lithium ion battery is placed in a 25°C (or 45°C) thermostat for 2 hours to make the lithium ion battery reach a constant temperature. The lithium ion battery reaching the constant temperature is charged at a constant current of 0.5C (25°C) or 1C (45°C) to a voltage of 4.4V, then charged at a constant voltage of 0.05C, and then discharged at a constant current of 0.5 to a voltage of 3V, which is one cycle, and the discharge capacity is recorded. Cycle capacity retention rate = discharge capacity of the nth cycle / first cycle discharge capacity*100%.

[0053] (2) Test of storage performance of lithium ion battery under full charge

[0054] After the cell is fully charged, the thickness M0 of the cell is tested. After being placed in a thermostat at 60°C for 15 days, the thickness M1 at room temperature is tested. Cell thickness growth rate = (M1-M0) / M0*100%.

[0055] (4) Test of rate charging

[0056] The lithium ion battery is placed in a 25°C thermostat for 2 hours to make the lithium ion battery reach a constant temperature. The lithium ion battery reaching the constant temperature is charged at a constant current of 3C or 0.5C to a voltage of 4.4V, and the charge capacity is recorded. Capacity retention rate = 3C charge capacity / 0.5C charge capacity*100%.

[0057] 3. Test results

[0058] The implementation scheme of the examples is shown in Table 1, all the examples are prepared by the method of secondary injection and formation, all use the method of double-layer coating, and the organic matter in the table is added in the secondary injection; the comparative examples are prepared by the method of primary injection and formation. The first injection amount of examples 1-9 is 65%, and the first injection amount of example 10 is 75%; organic matter 1 is hexanetricarbonitrile, organic matter 2 is tris(trimethylsilyl) phosphate, and organic matter 3 is tetraethenylsilane. The test results are listed in Table 2.

[0059] Table 1 Implementation scheme of examples and comparative examples

[0060]

[0061] Table 2 Test results

[0062]

[0063]

[0064] From the above results, first, the examples 1-18 in the particle size range of the step distribution of the negative active material after secondary injection all achieve good capacity retention rate, the high temperature cycle capacity retention rate is further improved, the thickness growth rate is stably controlled, and the capacity retention rate can basically reach more than 89% under 3C fast charging rate, and the internal resistance is significantly reduced.

[0065] Examples 1-3 and comparative examples 1, 5 are compared as a group, which verifies that the particle size step distribution, secondary injection and formation voltage all play a role in improving the comprehensive performance of high energy density fast charging. Examples 4 and comparative example 2 as a group, and examples 5 and comparative example 3 as a group, also show the same verification conclusion.

[0066] Examples 2, 4, 5 are compared as a group, which shows the influence of different types of additives in secondary injection on performance. We verified that the trinitrile additive has higher advantages in room temperature and high temperature cycle capacity retention rate during fast charging.

[0067] Examples 2, 6, 7 are compared as a group, which verifies the influence of particle size step distribution change on performance. Example 6 shows that when the inner layer active material moves to the lower D50 direction, although the 3C retention rate increases and the internal resistance further decreases, the cycle capacity of the battery will decrease and the thermal deformation will increase. The particle size range of the inner layer active material is balanced and optimized in our selected range. Example 7 shows that when the outer layer active material moves to the lower D50 direction, the 3C retention rate is also observed to increase and the internal resistance further decreases, while the cycle capacity of the battery will decrease and the thermal deformation will increase. It can be seen that the particle size range of the outer layer active material is also balanced and optimized in our selected range.

[0068] Examples 8 and comparative example 4 are compared as a group, which verifies the universality of our technical scheme matching the positive electrode material. The NCM ternary system shows the same fast charging improvement effect as the LCO system.

[0069] As a group of comparison, we verified the influence of the step distribution of the negative active material particle size on the two-step liquid injection condition. Under the condition of unchanged formation voltage, the comprehensive performance decreased when the surface layer D50 was reduced alone (Example 7) or the surface layer thickness was increased (Example 9); the battery comprehensive performance was effectively stabilized when the battery liquid injection amount was increased and the formation voltage was reduced at the same time (Example 10). Therefore, the one-time liquid injection amount can be reduced as the outer layer active material particle D50 increases and the thickness decreases, and at the same time, the one-time formation cut-off voltage can be reduced as the outer layer D50 decreases and the outer layer thickness increases.

[0070] As a group of comparison, Examples 2, 11-13, as a group of comparison, Examples 4, 14-15, and as a group of comparison, Examples 5, 16-18, respectively verify the optimal addition amount of different types of additive systems in the two-step liquid injection process within the addition amount range of each type of design. From the example results, the optimal addition amount of hexanetricarbonitrile is about 1%, and the optimal addition amount of nitrile can be 3% when converted to mononitrile according to the multiple of the nitrile group contained; the optimal addition amount of tris(trimethylsilyl) phosphate is about 0.5%, and the optimal addition amount of tetra-vinyl silane is about 0.3%.

[0071] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A preparation method of a high-voltage lithium ion fast-charging battery, wherein the particle size of the active material of the negative electrode sheet adopts a step distribution, and the electrolyte adopts two-step liquid injection and formation, the voltage of the battery is greater than 4.35 V, the step distribution of the negative electrode sheet is designed as two layers, and the particle size D50 of the active material decreases from the current collector outward; when the particle size D50 of the outer layer active material is 6-10 pm, the one-time liquid injection amount of the two-step liquid injection and formation is 70%-80% of the total liquid injection amount, the secondary liquid injection is the balance, and the one-time formation cutoff voltage is 3.5-3.7 V; when the particle size D50 of the outer layer active material is 11-13 pm, the one-time liquid injection amount of the two-step liquid injection and formation is 60%-70% of the total liquid injection amount, the secondary liquid injection is the balance, and the one-time formation cutoff voltage is 3.7-3.8 V; the secondary formation cutoff voltage is greater than 3.8 V; the thickness of the outer layer active material accounts for 5%-12% of the total thickness of the outer layer active material and the inner layer active material; the electrolyte of the secondary liquid injection is supplemented with an additive for positive electrode film formation alone or an additive for positive and negative electrode film formation, including at least one of the following: phosphoric acid ester, nitrile, and an alkenyl-, alkynyl-, or cyano-containing compound; the percentage of the supplemental additive in the total amount of the electrolyte of the secondary liquid injection is as follows: nitrile: 0.5%-6% as calculated from the number of nitrile groups contained and converted into a single nitrile; phosphoric acid ester: 0.1%-1%; alkenyl-containing silane: 0.1%-0.5%; and the capacity retention rate of the high-voltage lithium ion fast-charging battery reaches 89% or more at a 3C fast-charging rate. The thickness of the outer layer active material is 8-30 pm. The electrolyte of the secondary liquid injection is supplemented with a trinitrile additive. The percentage of the supplemental additive in the total amount of the electrolyte of the secondary liquid injection is as follows: nitrile: 3%±0.6% as calculated from the number of nitrile groups contained and converted into a single nitrile; phosphoric acid ester: 0.5%±0.1%; and alkenyl-containing silane: 0.3%±0.1%. The electrolyte of the one-time liquid injection is supplemented with an additive for positive and negative electrode film formation or an additive for negative electrode film formation, including at least one of the following: 0-2% propylene carbonate, 0-20% fluoroethylene carbonate, 0-2% vinyl sulfonate, 0-8% 1,3 propane sulfonolactone, 0-1% 1,3 propylene sulfonolactone, 0-5% lithium difluorophosphate, 0-3% lithium difluoro oxalate borate, 0-2% lithium bisoxalate borate, 0-3% lithium tetrafluoroborate, 0-2% 1,3 dioxane, 0-2% 1,4 dioxane, 0-5% lithium bisfluorosulfonylimide, 0-5% lithium bis-trifluoromethylsulfonylimide, in terms of mass percentage, and the lower limit is not 0. ​ ​ ​ ​ ​ 2. The method of making a high voltage lithium ion fast charge battery of claim 1, wherein, ​ 3. The method of making a high voltage lithium ion fast charge battery of claim 1, wherein, ​ 4. The method of making a high voltage lithium ion fast charge battery of claim 1, wherein, ​ 5. The method of making a high voltage lithium ion fast charge battery of claim 1, wherein, ​ 6. The method of making a high voltage lithium ion fast charge battery of claim 1, wherein, The positive active material is at least one of a transition metal composite lithium oxide or a transition metal phosphate compound, the chemical formula of the transition metal composite oxide, the transition metal phosphate compound is respectively Li x M1O2, Li y M2PO4, xLi2MnO3·(1-x)LiM3O2, Li z (M4)2O4 wherein, M1, M2, M3, M4 respectively represent one or more transition metal elements, 0.05 ≤ x ≤ 1.20, 0.05 ≤ y ≤ 1.20, 0.05 ≤z ≤ 1.20; the negative electrode active material is at least one of natural graphite, artificial graphite, mesophase carbon microbeads, hard carbon, soft carbon, silicon-oxygen material, silicon-oxygen-carbon composite, Li-Sn alloy, Li-Ge alloy, Li-Sn-O alloy, Sn, SnO, SnO2, spinel structure lithiumized TiO2-Li4Ti5O 12 , MXene.

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