A high-nickel lithium battery

Abstract

The present invention relates to a high-nickel lithium battery. In order to improve the comprehensive performance of the high-nickel lithium battery, such as room-temperature cycle performance, low-temperature cycle performance, low-temperature electrolyte lithium plating phenomenon, high-temperature storage performance, etc., the present invention provides a high-nickel lithium battery, which includes a positive electrode sheet, a negative electrode sheet and an electrolyte. The electrolyte includes a lithium salt, an additive and an organic solvent. The active material of the positive electrode sheet is LiNi x Co 1‑x‑ y M y O2 (1≥x≥0.5, x + y≤1), where M is manganese or aluminum in the formula, and the additive includes a tripyridyl phosphite compound and a conventional film-forming additive. The room-temperature cycle performance and low-temperature cycle performance of the high-nickel lithium battery of the present invention are improved, the lithium plating phenomenon at low temperature is significantly inhibited, and the battery swelling at high temperature is inhibited. It can be seen that the comprehensive performance is significantly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium batteries, and particularly relates to a high-nickel lithium battery. Background Art

[0002] The advantages of high-nickel oxide cathode materials are high specific capacity and energy density, while the disadvantages are poor structural stability and high-temperature performance. This is mainly because the particles on the surface of high-nickel oxide cathode materials are extremely prone to the phase transformation from layered structure to spinel structure, which causes cracks or structural collapse in the high-nickel materials, and then creates new contact interfaces between the electrode sheet and the electrolyte, accelerating the decomposition of the electrolyte to generate more gas, ultimately affecting the cycle performance of the battery. Moreover, the occurrence of the phase transformation process in the cathode material will also cause the precipitation of transition metal ions in the material. The precipitated transition metal ions will be reduced and deposited on the surface of the anode to generate dendrites, and the dendrites have the risk of piercing the diaphragm and causing battery short circuit, thus reducing the safety of the battery. In addition, conventional electrolytes are prone to crystallization at low temperatures, and the capacity retention rate is also significantly reduced. At high temperatures, the thickness increases and the capacity retention rate also decreases significantly. With the increasingly wide application scenarios of high-nickel lithium batteries, higher requirements are put forward for the low-temperature performance and high-temperature performance of high-nickel lithium batteries.

[0003] Therefore, how to comprehensively improve the normal-temperature cycle performance, low-temperature cycle performance, low-temperature electrolyte lithium plating phenomenon, high-temperature storage performance, and safety performance of high-nickel lithium batteries has become the research focus of high-nickel lithium batteries at present. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-nickel lithium battery with excellent normal-temperature cycle performance, low-temperature cycle performance, high-temperature storage performance, and capable of significantly suppressing low-temperature lithium plating phenomenon and high-temperature swelling phenomenon.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A high-nickel lithium battery, which includes a positive electrode sheet, a negative electrode sheet, and an electrolyte. The electrolyte includes a lithium salt, an additive, and an organic solvent. The active material of the positive electrode sheet is LiNi x Co 1-x-y M y O2 (1≥x≥0.5, x + y≤1), where M in the formula is manganese or aluminum. The additive includes one or more of the tripyridyl phosphite compounds shown in Formula I,

[0007]

[0008] Among them, R1 to R 12 independently selected from a hydrogen atom, a halogen atom, a cyano group, an amino group, a nitro group, a silyl group, an unsubstituted or arbitrarily substituted C1-C10 alkyl, unsubstituted or optionally substituted C2-C 10 alkenyl, unsubstituted or optionally substituted C6-C 14 aryl, unsubstituted or optionally substituted C1-C 14 alkoxy, unsubstituted or optionally substituted C6-C 14 aryloxy, and the substituents of the optionally substituted ones are F, Cl, Br or cyano group.

[0009] Preferably, R1-R 12 independently selected from a hydrogen atom, a halogen atom, a cyano group, an amino group, a nitro group, a silyl group, an unsubstituted or optionally substituted C1-C4 alkyl group, an unsubstituted or optionally substituted C2-C4 alkenyl group, an unsubstituted or optionally substituted C6-C8 aryl group, an unsubstituted or optionally substituted C1-C4 alkoxy group, an unsubstituted or optionally substituted C6-C8 aryloxy group, and the substituents of the optionally substituted ones are F, Cl or cyano group.

[0010] More preferably, R1-R 12 independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, an F-substituted C1-C4 alkyl group or an unsubstituted C2-C4 alkenyl group.

[0011] Even more preferably, R1-R 12 independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a trifluoromethyl group or a vinyl group.

[0012] According to some specific and preferred embodiments, the additive includes one or more of the compounds shown in the following structural formulas:

[0013]

[0014] Preferably, the feeding mass of the tripyridyl phosphite compound shown in Formula I is 0.1-10% of the total mass of the electrolyte.

[0015] Even more preferably, the feeding mass of the tripyridyl phosphite compound shown in Formula I is 1-10% of the total mass of the high-nickel lithium battery electrolyte.

[0016] Even further preferably, the feeding mass of the tripyridyl phosphite compound shown in Formula I is 3-8% of the total mass of the high-nickel lithium battery electrolyte.

[0017] Preferably, the additive further includes a conventional film-forming additive, which is selected from one or more of fluoroethylene carbonate, ethylene sulfate, propylene sulfate, vinylene carbonate, 1,3-propane sultone, succinic anhydride, glutaric anhydride, adiponitrile, succinonitrile, tris(trimethylsilyl) phosphate, tris(2,2,2-trifluoroethyl) phosphite, tris(trimethylsilyl) borate or triphenyl phosphite.

[0018] Preferably, the feeding mass of the conventional film-forming additive is 1-10% of the total mass of the electrolyte.

[0019] More preferably, the feeding mass of the conventional film-forming additive is 1-8% of the total mass of the electrolyte.

[0020] Even more preferably, the feeding mass of the conventional film-forming additive is 2-6% of the total mass of the electrolyte.

[0021] More preferably, the conventional film-forming additive is a composition of fluoroethylene carbonate, ethylene sulfate and adiponitrile, and the feeding mass ratio of fluoroethylene carbonate, ethylene sulfate and adiponitrile is 1-5:0.5-2:1.

[0022] Preferably, the lithium salt is selected from one or more of LiBF4, LiPF6, LiPF2O2, LiAsF6, LiClO4, LiFSI, LiTFSI, LiBOB, LiDFOB, LiDFOP, LiN(SO2CF3)2, LiN(SO2F)2.

[0023] Preferably, the concentration of the lithium salt is 0.5-2.5 mol / L.

[0024] More preferably, the concentration of the lithium salt is 0.8-2.0 mol / L.

[0025] Even more preferably, the concentration of the lithium salt is 0.8-1.5 mol / L.

[0026] Preferably, the organic solvent is selected from one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethylene carbonate, propylene carbonate, methyl formate, ethylene carbonate, propylene carbonate, vinylene carbonate, ethyl acetate, ethyl propionate, methyl acetate, propyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, γ-butyrolactone.

[0027] More preferably, the non-aqueous organic solvent is a mixture of dimethyl carbonate (DMC), ethylene carbonate (EC), propylene carbonate (PC) and ethyl methyl carbonate (EMC).

[0028] Preferably, the negative electrode sheet includes a negative electrode active material capable of accepting or releasing lithium ions, and the negative electrode active material includes one or more of lithium metal, lithium alloy, crystalline carbon, amorphous carbon, carbon fiber, hard carbon, or soft carbon.

[0029] More preferably, the crystalline carbon includes one or more of natural graphite, graphitized coke, graphitized MCMB, and graphitized mesophase pitch carbon fiber.

[0030] More preferably, the lithium alloy includes an alloy of lithium and one or more of aluminum, zinc, silicon, tin, gallium, or antimony.

[0031] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0032] By adding the tripyridyl phosphite compound shown in Formula I to the electrolyte of the high-nickel lithium battery, the present invention simultaneously improves the room-temperature cycle performance, low-temperature cycle performance, and high-temperature storage performance of the high-nickel lithium battery. Further, by compounding with other film-forming additives, it can effectively inhibit the lithium deposition phenomenon at low temperature and the bulging phenomenon at high temperature of the high-nickel lithium battery, so that the comprehensive performance of the high-nickel lithium battery is significantly improved. Detailed Embodiments

[0033] The present invention will be further described below in conjunction with embodiments. However, the present invention is not limited to the following embodiments. The implementation conditions adopted in the embodiments can be further adjusted according to different requirements of specific uses, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0034] In order to improve the comprehensive performance of the high-nickel lithium battery, the inventors have conducted a large number of studies and experimental verifications and proposed a new high-nickel lithium battery.

[0035] According to the present invention, the high-nickel lithium battery includes a positive electrode sheet, a negative electrode sheet, and an electrolyte. The electrolyte includes a lithium salt, an additive, and an organic solvent. The active material of the positive electrode sheet is LiNi x Co 1-x-y M y O2 (1≥x≥0.5, x + y≤1), where M in the formula is manganese or aluminum, and the additive includes one or more of the tripyridyl phosphite compounds shown in Formula I,

[0036]

[0037] wherein, R1~R 12 are independently selected from a hydrogen atom, a halogen atom, a cyano group, an amino group, a nitro group, a silyl group, an unsubstituted or arbitrarily substituted C1~C10 alkyl, unsubstituted or optionally substituted C2-C 10 alkenyl, unsubstituted or optionally substituted C6-C 14 aryl, unsubstituted or optionally substituted C1-C 14 alkoxy, unsubstituted or optionally substituted C6-C 14 aryloxy, and the substituents of the optionally substituted ones are F, Cl, Br or cyano.

[0038] According to the present invention, the additive further includes a conventional film-forming additive, and the conventional film-forming additive is selected from one or more of fluoroethylene carbonate, ethylene sulfate, propylene sulfate, vinylene carbonate, 1,3-propane sultone, succinic anhydride, glutaric anhydride, adiponitrile, succinonitrile, tris(trimethylsilyl) phosphate, tris(2,2,2-trifluoroethyl) phosphite, tris(trimethylsilyl) borate or triphenyl phosphite.

[0039] The N atom in the pyridine ring structure of the tripyridyl phosphite compound has a strong complexing ability, which can bind to the transition metal ions and free HF dissolved in the electrolyte, avoid the electrodeposition of transition metal ions on the surface of the negative electrode, and can also avoid the destruction of the SEI film by HF. At the same time, it also shows the advantage of improving the battery safety performance and has a certain application prospect in high-voltage battery systems. The phosphite structure can reduce the internal resistance of the battery and has a certain flame retardancy, thereby improving the battery safety performance.

[0040] The tripyridyl phosphite compound is used in combination with a conventional film-forming additive to simultaneously improve the room-temperature cycle performance, low-temperature cycle performance, high-temperature storage performance and safety performance of the high-nickel lithium battery.

[0041] According to some embodiments, R1-R 12 are preferably independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a trifluoromethyl group or a vinyl group.

[0042] According to some embodiments, the conventional film-forming additive is a composition of fluoroethylene carbonate, ethylene sulfate and adiponitrile with a feed mass ratio of 1-5:0.5-2:1.

[0043] According to some embodiments, the organic solvent is a mixture of dimethyl carbonate (DMC), ethylene carbonate (EC), propylene carbonate (PC) and ethyl methyl carbonate (EMC) with a mass ratio of 1-3:2-4:1:3-5.

[0044] According to some embodiments, the lithium salt is lithium hexafluorophosphate.

[0045] Although LiPF6 has problems such as poor thermal stability and easy hydrolysis, which can easily cause rapid attenuation of battery capacity and pose safety hazards, when the described tripyridyl phosphite compound and the described conventional film-forming additive are added to the electrolyte, the above-mentioned disadvantages of LiPF6 are overcome, and the comprehensive performance of the high-nickel lithium battery is improved without increasing the cost of the lithium salt.

[0046] The cut-off charging voltage of the high-nickel lithium battery of the present invention can reach 4.6V, and it still has excellent comprehensive performance under high-voltage conditions.

[0047] The technical solutions and technical effects of the present invention will be further elaborated below in conjunction with examples and comparative examples.

[0048] In the following examples and comparative examples, the tripyridyl phosphite compounds involved are as follows:

[0049]

[0050]

[0051] Synthesis route of tripyridyl phosphite (Compound (1)): Add polyethylene glycol to 4-hydroxypyridine, and dropwise add phosphorus trichloride during stirring. Control the reaction temperature at 75-85 °C under a pressure of about 800 Pa, and the reaction time is 4-6 h. After the reaction is completed, distill off the unreacted phosphorus trichloride under normal pressure to obtain tripyridyl phosphite.

[0052] Synthesis route of Compound (2): Mix 2-vinylpyridine with ethyl acetate, stir evenly at room temperature, and dropwise add thionyl chloride using a dropping funnel. After the addition is complete, heat the oil bath to the reflux state and stir for 4 h. The color of the mixture gradually changes from yellow to brown. After standing and separating, take the lower black solid, dry it, rinse it with absolute ethanol, and then dry it again to obtain 4-hydroxy-2-vinylpyridine. Add polyethylene glycol to 4-hydroxy-2-vinylpyridine, and dropwise add phosphorus trichloride during stirring. Control the reaction temperature at 75-85 °C under a pressure of about 800 Pa, and the reaction time is 4-6 h. After the reaction is completed, distill off the unreacted phosphorus trichloride under normal pressure to obtain Compound (2).

[0053] Synthesis route of Compound (3): Add polyethylene glycol to 4-hydroxy-2-cyanopyridine (CAS 475057-86-4), and dropwise add phosphorus trichloride during stirring. Control the reaction temperature at 75-85 °C under a pressure of about 800 Pa, and the reaction time is 4-6 h. After the reaction is completed, distill off the unreacted phosphorus trichloride under normal pressure to obtain Compound (3).

[0054] Preparation route of compound (4): Polyethylene glycol was added to 4-hydroxy-2-trifluoromethyl-3,5,6-trifluoropyridine (Application No.: PCT / JP2018 / 039843). Phosphorus trichloride was added dropwise during stirring. The reaction temperature was controlled at 75 - 85 °C under a pressure of about 800 Pa, and the reaction time was 4 - 6 h. After the reaction was completed, unreacted phosphorus trichloride was removed by distillation at atmospheric pressure to obtain compound (4).

[0055] Preparation route of compound (5): Polyethylene glycol was added to 4-hydroxy-3-nitro-2,6-dichloropyridine (Application No.: AU1958041193). Phosphorus trichloride was added dropwise during stirring. The reaction temperature was controlled at 75 - 85 °C under a pressure of about 800 Pa, and the reaction time was 4 - 6 h. After the reaction was completed, unreacted phosphorus trichloride was removed by distillation at atmospheric pressure to obtain compound (5).

[0056] Preparation route of compound (6) (Application No. 202010878715.2): Sodium 3,5,6-trichloropyridin-2-olate was dissolved in water. After heating to 70 - 75 °C during stirring, hydrochloric acid was added dropwise to adjust the pH value to 2 - 4. After filtration, 2-hydroxy-3,5,6-trichloropyridine was obtained; Dehydrating agent toluene was added to 2-hydroxy-3,5,6-trichloropyridine, and the temperature was raised to 100 °C - 110 °C during stirring for dehydration reaction; After the dehydration reaction was completed, the temperature was lowered to 35 °C - 40 °C, polyethylene glycol was added, and phosphorus trichloride was added dropwise during stirring. The reaction temperature was controlled at 75 °C - 85 °C under a pressure of about 800 Pa. After the reaction was completed, unreacted phosphorus trichloride was distilled off at atmospheric pressure, and then the dehydrating agent toluene was distilled off under reduced pressure to obtain tris(3,5,6-trichloropyridinyl) phosphite, that is, compound (6).

[0057] In the following examples and comparative examples, unless otherwise specified, the raw materials involved are all commercially available products.

[0058] Examples 1 - 15 and Comparative Examples 1 - 3

[0059] (1) Preparation of electrolyte

[0060] In a glove box under an argon atmosphere (with water and oxygen contents both less than 0.1 ppm), four solvents, dimethyl carbonate (DMC), ethylene carbonate (EC), propylene carbonate (PC), and ethyl methyl carbonate (EMC), were mixed in a mass ratio of 2:3:1:4, and then the electrolytes of the examples and comparative examples were prepared according to Table 1.

[0061] Table 1

[0062]

[0063]

[0064] (2) Preparation of the positive electrode sheet

[0065] Dissolve polyvinylidene fluoride (PVDF) with a mass percentage of 2.8% in 1-methyl-2-pyrrolidone solution, and add LiNi 0.6 Co 0.2 Mn 0.2 O2 with a mass percentage of 95.2% and 2% conductive agent carbon black into the above solution and mix evenly. After coating the mixed slurry on both sides of the aluminum foil, dry it and roll it to obtain the positive electrode sheet.

[0066] (3) Preparation of the negative electrode sheet

[0067] Dissolve SBR binder with a mass percentage of 3.4% and CMC thickener with a mass percentage of 1.3% in an aqueous solution, add graphite with a mass percentage of 95.3% into the above solution, mix evenly. After coating the mixed slurry on both sides of the copper foil, dry it and roll it to obtain the negative electrode sheet.

[0068] (4) Fabrication of the high-nickel lithium battery

[0069] Make a soft-pack battery cell by winding the above-prepared positive electrode sheet, negative electrode sheet and separator, package it with a polymer, pour the above-prepared electrolyte, and fabricate a high-nickel lithium battery with a capacity of 1500 mAh through processes such as formation.

[0070] (5) Battery performance test

[0071] Overcharge performance test: Take 50 high-nickel lithium batteries obtained from the above Examples 1-15 and Comparative Examples 1-3 respectively, charge them at a constant current of 1C and a constant voltage to 4.6V, with a cut-off current of 0.05C, and then overcharge the batteries at 1C for 1h to detect the battery status. The results are shown in Table 2. Among them, a test battery that does not show phenomena such as bulging (bulging rate < 10%), leakage, smoking, fire, rupture, etc. is considered qualified.

[0072] Table 2 Results of the overcharge performance test of the battery

[0073]

[0074]

[0075] From the test results in Table 2, it can be seen that compared with Comparative Example 1, for Examples 1 to 15, there was no smoking phenomenon during the 1C overcharge for 1 h after the high-nickel lithium battery was fully charged, and the bulging phenomenon was also significantly improved; compared with Comparative Examples 2 and 3, for Examples 5 and 7 to 15, when the content of tripyridyl phosphite (containing both phosphite and pyridine functional groups) was greater than or equal to 1.5 wt% compared with TPP with a single functional group and pentafluoropyridine, all the batteries in which it was located were qualified, greatly improving the safety performance of the battery.

[0076] Normal temperature cycling test conditions: The battery was subjected to 400 charge-discharge cycles in the voltage range of 2.75 - 4.35 V at a charge-discharge rate of 1 / 1C, and the discharge capacities in the first week and the 400th week were recorded respectively.

[0077] Capacity retention rate at the 400th week (%) = Discharge capacity at the 400th week / Discharge capacity in the first week * 100%.

[0078] Low temperature cycling test conditions: At -20°C, the battery was subjected to 200 charge-discharge cycles at a charge-discharge rate of 1 / 1C, and the discharge capacities in the first week and the 200th week were recorded respectively.

[0079] Capacity retention rate at the 200th week (%) = Discharge capacity at the 200th week / Discharge capacity in the first week * 100%.

[0080] High temperature storage test conditions: First, the battery after formation was charged and discharged once at 1C at room temperature, and the discharge capacity was recorded as Q1. Then the battery was fully charged at 1C with a cut-off current of 0.05C. Before the 7-day storage at 60°C, the thickness of the battery was measured and recorded as t1. After the high temperature storage was completed and the battery was completely cooled, the thickness of the battery was measured again and recorded as t2. Then the taken-out battery was discharged at 1C, and the discharge capacity of the battery was recorded as Q2.

[0081] Thickness change rate = (t2 - t1) / t1 * 100%;

[0082] Storage capacity retention rate = Q2 / Q1 * 100%.

[0083] The test results are shown in Table 3:

[0084] Table 3 Test results of the performance of the battery at normal temperature, low temperature and high temperature storage

[0085]

[0086]

[0087] As can be seen from Table 3, compared with Comparative Examples 1 to 3, the normal temperature cycle performance of Examples 1 to 15 has been improved; in terms of high temperature storage, Examples 1 to 15 have better inhibited the increase in battery thickness and at the same time improved the capacity retention rate of the battery; at low temperature, the cycle performance of Examples 1 to 15 has been significantly improved, and the lithium plating phenomenon of the battery at low temperature has also been significantly inhibited, indicating that the comprehensive performance of the high-nickel battery of the present invention has been significantly improved.

[0088] The above embodiments are only for illustrating the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It is not intended to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A high-nickel lithium battery, which comprises a positive electrode sheet, a negative electrode sheet and an electrolyte. The electrolyte comprises a lithium salt, an additive and an organic solvent, and is characterized in that, The active material of the positive electrode sheet is LiNi x Co 1-x-y M y O2 (1≥x≥0.5, x + y≤1), where M is manganese or aluminum, and the additive includes one or more of the tripyridyl phosphite compounds shown in Formula I Among them, R1 to R 12 are independently selected from a hydrogen atom, a halogen atom, a cyano group, an amino group, a nitro group, a silyl group, an unsubstituted or optionally substituted C1-C 10 alkyl group, an unsubstituted or optionally substituted C2-C 10 alkenyl group, an unsubstituted or optionally substituted C6-C 14 aryl group, an unsubstituted or optionally substituted C1-C 14 alkoxy group, an unsubstituted or optionally substituted C6-C 14 aryloxy group, and the substituent of the optionally substituted group is F, Cl, Br or a cyano group.

2. The high-nickel lithium battery according to claim 1, characterized in that, R1 to R 12 independently selected from a hydrogen atom, a halogen atom, a cyano group, an amino group, a nitro group, a silyl group, an unsubstituted or optionally substituted C1-C4 alkyl group, an unsubstituted or optionally substituted C2-C4 alkenyl group, an unsubstituted or optionally substituted C6-C8 aryl group, an unsubstituted or optionally substituted C1-C4 alkoxy group, an unsubstituted or optionally substituted C6-C8 aryloxy group, and the substituent of the optionally substituted group is F, Cl or a cyano group.

3. The high-nickel lithium battery according to claim 2, wherein R1 to R 12 independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, an F-substituted C1-C4 alkyl group or an unsubstituted C2-C4 alkenyl group.

4. The high-nickel lithium battery according to claim 3, characterized in that, R1 to R 12 are independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a trifluoromethyl group or a vinyl group.

5. The high-nickel lithium battery according to claim 4, wherein The additive(s) include(s) one or more of the compounds represented by the following structural formulae:

6. The high-nickel lithium battery according to claim 1, characterized in that, The feeding mass of the tripyridyl phosphite compound represented by Formula I is 0.1-10% of the total mass of the electrolyte.

7. The high-nickel lithium battery according to claim 1, characterized in that The additive further includes a conventional film-forming additive, which is selected from one or more of fluorinated ethylene carbonate, ethylene sulfate, propylene sulfate, vinylene carbonate, 1,3-propane sultone, succinic anhydride, glutaric anhydride, adiponitrile, succinonitrile, tris(trimethylsilyl) phosphate, tris(2,2,2-trifluoroethyl) phosphite, tris(trimethylsilyl) borate or triphenyl phosphite. The feeding mass of the conventional film-forming additive is 1-10% of the total mass of the electrolyte.

8. The high-nickel lithium battery according to claim 7, characterized in that, The conventional film-forming additive is a composition of fluorinated ethylene carbonate, ethylene sulfate and adiponitrile, and the feeding mass ratio of fluorinated ethylene carbonate, ethylene sulfate and adiponitrile is 1-5:0.5-2:

1.

9. The high-nickel lithium battery according to claim 1, characterized in that, The lithium salt(s) is / are selected from one or more of LiBF4, LiPF6, LiPF2O2, LiAsF6, LiClO4, LiFSI, LiTFSI, LiBOB, LiDFOB, LiDFOP, LiN(SO2CF3)2, LiN(SO2F)2; and / or, the concentration of the lithium salt is 0.5-2.5 mol / L; and / or, the organic solvent(s) is / are selected from one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethylene carbonate, propylene carbonate, methyl formate, ethylene carbonate, propylene carbonate, vinylene carbonate, ethyl acetate, ethyl propionate, methyl acetate, propyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, γ-butyrolactone.

10. The high-nickel lithium battery according to claim 1, characterized in that, The negative electrode sheet includes a negative electrode active material capable of accepting or releasing lithium ions, and the negative electrode active material includes one or more of lithium metal, lithium alloy, crystalline carbon, amorphous carbon, carbon fiber, hard carbon or soft carbon.

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