Non-aqueous electrolyte and lithium ion battery containing the same

Abstract

The application provides a non-aqueous electrolyte and a lithium ion battery. The non-aqueous electrolyte comprises an electrolyte salt, a non-aqueous organic solvent and an additive, the additive comprises a compound A, a structural formula of the compound A is shown in formula I, wherein R1 is selected from fluorine, a substituted or unsubstituted aromatic group and a substituted or unsubstituted C1-C6 alkyl group, R2, R3 and R4 are each independently selected from hydrogen, fluorine, a substituted or unsubstituted C1-C6 alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aromatic group and a substituted or unsubstituted C1-C6 alkyl group, and R5, R6 and R7 are each independently selected from hydrogen, a substituted or unsubstituted aromatic group and a substituted or unsubstituted C1-C6 alkyl group. The compound A can form an inner inorganic outer organic SEI film, the film can greatly promote lithium ion transmission, greatly reduce the charge transfer resistance of the lithium ion battery, promote the desolvation of lithium ions, stabilize the electrode-electrolyte interface, inhibit the catalytic decomposition of the electrolyte, and improve the high-temperature cycle performance of the battery.

Description

Technical Field

[0001] This invention relates to the field of energy storage device technology, particularly to secondary batteries, and even more particularly to a non-aqueous electrolyte and a lithium-ion battery containing the non-aqueous electrolyte. Background Technology

[0002] With the widespread application of electric vehicles and energy storage systems, the long-term reliability of batteries in complex climatic environments has become a core concern. Especially in the harsh operating conditions of tropical and subtropical regions and high summer temperatures, battery systems face continuous testing under high-temperature cycling conditions.

[0003] High-temperature environments significantly accelerate a series of complex physicochemical processes within batteries. On the one hand, increased temperature facilitates the diffusion of lithium ions in electrode materials; on the other hand, it provides intense kinetic conditions for various interfacial side reactions. During long-term high-temperature cycling, the thermocatalytic decomposition reaction between the electrolyte and highly active electrode materials continues, leading to a continuous thickening of the solid electrolyte interfacial film, compositional imbalance, and the dissolution and migration of transition metal ions. This results in a significant increase in battery internal resistance and a continuous decline in usable capacity. Simultaneously, the electrode materials themselves may undergo irreversible lattice structure evolution and phase transitions under the coupled effects of thermal and chemical stresses, further impairing their cycle stability and thermal safety.

[0004] Therefore, developing electrolytes with excellent high-temperature resistance and batteries with long cycle life is a key step in improving the safety and efficiency of energy systems and achieving sustainable development. Summary of the Invention

[0005] Based on the above problems, the purpose of this invention is to provide a non-aqueous electrolyte and a lithium-ion battery. Compound A in the non-aqueous electrolyte can form an inner inorganic and outer organic SEI film. This film can greatly promote lithium-ion transport, effectively reduce the charge transfer resistance of the lithium-ion battery, promote the desolvation of lithium ions, and protect the inner inorganic SEI from dissolution. The outer organic SEI is more resilient, stabilizes the electrode-electrolyte interface, inhibits the catalytic decomposition of the electrolyte, and improves the high-temperature cycle performance of the battery.

[0006] To achieve the above objectives, the present invention provides a non-aqueous electrolyte comprising an electrolyte salt, a non-aqueous organic solvent, and an additive, wherein the additive comprises compound A, and the structural formula of compound A is shown in Formula 1.

[0007] Formula 1 Wherein, R1 is selected from fluorine, substituted or unsubstituted aromatic groups, substituted or unsubstituted C1-C6 alkyl groups; R2, R3, and R4 are each independently selected from hydrogen, fluorine, substituted or unsubstituted alkoxy groups containing C1-C6, substituted or unsubstituted amino groups, substituted or unsubstituted aromatic groups, substituted or unsubstituted C1-C6 alkyl groups; and R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted aromatic groups, substituted or unsubstituted C1-C6 alkyl groups.

[0008] The additive in the non-aqueous electrolyte of this invention includes compound A as shown in Formula 1, which has a sulfonyl-vinylazolidinone structure that preferentially adsorbs at the negative electrode interface during charging. The sulfonyl group preferentially forms an inorganic solid electrolyte interface film containing lithium (sulfinic)sulfonate on the negative electrode surface. Subsequently, the outer vinylazolidinone polymerizes on the outer layer, ultimately forming an inner inorganic and outer organic SEI film. Compared to SEI films with a higher organic content, this inorganic-rich SEI film significantly promotes lithium-ion transport, effectively reduces the charge transfer resistance of lithium-ion batteries, and promotes lithium-ion desolvation. Compared to inorganic-rich SEI films, the outer organic SEI film better protects the inner inorganic SEI from dissolution. Simultaneously, the outer organic SEI is more resilient, stabilizing the electrode-electrolyte interface, inhibiting the catalytic decomposition of the electrolyte, and thus improving the battery's cycle performance.

[0009] As a technical solution of the present invention, R1 is selected from fluorine, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups; R2, R3, and R4 are each independently selected from hydrogen, fluorine, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups; R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups.

[0010] As a technical solution of the present invention, R1 is selected from substituted or unsubstituted aromatic groups, R2, R3, and R4 are each independently selected from hydrogen, substituted or unsubstituted C1-C4 alkyl groups, and R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted C1-C4 alkyl groups.

[0011] As one technical solution of the present invention, compound A is selected from at least one of compounds one to five.

[0012] Compound 1 Compound 2

[0013] Compound 3 Compound 4

[0014] Compound Five As a technical solution of the present invention, based on the mass of the electrolyte salt, the non-aqueous organic solvent and the additive being 100%, the mass percentage of compound A is 0.05~5.00%.

[0015] As one technical solution of the present invention, the electrolyte salt is a lithium salt, which is selected from at least one of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(oxalate-borate), lithium difluorophosphate, lithium fluorosulfonate, lithium bis(oxalate-borate), lithium difluorooxalate-borate, lithium lower aliphatic carboxylic acids, lithium difluorobis(oxalate-phosphate), and lithium bis(oxalate-imide).

[0016] As a technical solution of the present invention, the non-aqueous organic solvent is selected from at least one of γ-butyrolactone, γ-valerolactone, δ-valerolactone, methyl acetate, ethyl acetate, ethyl propionate, butyl acetate, propyl propionate, butyl propionate, ethylene carbonate, propylene carbonate, butyl carbonate, pentylenetene carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl n-propyl carbonate, ethyl n-propyl carbonate, propylene carbonate, 1,3-dioxolane, 1,4-dioxane, crown ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2-trifluoromethyltetrahydrofuran, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.

[0017] A second aspect of the present invention provides a lithium-ion battery, comprising a positive electrode material, a negative electrode material and an electrolyte, wherein the electrolyte is selected from the aforementioned non-aqueous electrolytes.

[0018] As a technical solution of the present invention, the cathode material is selected from at least one of lithium iron phosphate materials, lithium manganese iron phosphate materials, lithium nickel cobalt manganese oxide materials, lithium nickel cobalt aluminum oxide materials, and lithium cobalt oxide materials.

[0019] As one technical solution of the present invention, the negative electrode material is selected from at least one of artificial graphite, natural graphite, lithium titanate, silicon-carbon composite material and silicon-oxygen composite material. Detailed Implementation

[0020] The non-aqueous electrolyte of this invention can reduce the charge transfer resistance of lithium-ion batteries and improve high-temperature cycle performance. The lithium-ion battery of this invention may include a positive electrode material, a negative electrode material, and a non-aqueous electrolyte. Among them, the positive electrode material may include layered oxides (such as lithium nickel cobalt manganese oxide materials, lithium nickel cobalt aluminum oxide materials, and lithium cobalt oxide materials), olivine-type materials (lithium iron phosphate materials, lithium manganese iron phosphate materials). Further, the lithium nickel cobalt manganese oxide materials may include lithium nickel cobalt manganese oxide, doped or coated lithium nickel cobalt manganese oxide, and the lithium nickel cobalt aluminum oxide materials may include lithium nickel cobalt aluminum oxide, doped or coated lithium nickel cobalt aluminum oxide. The chemical formula of nickel cobalt manganese oxide is LiNi x Co y Mn z M (1-x-y-z) O2, and the chemical formula of nickel cobalt aluminum oxide is LiNi x Co y Al z N (1-x-y-z) O2, where M is at least one of Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V, and Ti, N is at least one of Mn, Mg, Cu, Zn, Sn, B, Ga, Cr, Sr, V, and Ti, 0 < x < ........... 1, 0 < y < 1, 0 < z < 1, and x + y + z ≤ 1. The lithium cobalt oxide materials may include lithium cobalt oxide materials, doped or coated lithium nickel cobalt manganese lithium cobalt oxide materials. The lithium iron phosphate materials may include lithium iron phosphate, doped or coated lithium iron phosphate. The lithium manganese iron phosphate materials may include lithium manganese iron phosphate, doped or coated lithium manganese iron phosphate.

[0021] The negative electrode material is selected from at least one of artificial graphite, natural graphite, lithium titanate, silicon-carbon composite materials, and silicon-oxygen composite materials.

[0022] The non-aqueous electrolyte includes an electrolyte salt, a non-aqueous organic solvent, and an additive.

[0023] Based on the total mass of the electrolyte salt, non-aqueous organic solvent, and additive being 100%, the mass ratio of the electrolyte salt is 5 - 25%, further, the mass ratio of the electrolyte salt is 8 - 20%, and still further, the mass ratio of the electrolyte salt is 10 - 15%. As an example, the mass ratio of the electrolyte salt can be, but is not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 24%, 25%. The mass ratio of the electrolyte salt is not limited to the listed values, and other unlisted values within this range are equally applicable. The electrolyte salt is selected from at least one of LiPF6 (lithium hexafluorophosphate), LiClO4 (lithium perchlorate), LiBF4 (lithium tetrafluoroborate), lithium trifluoromethanesulfonate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(oxalato)borate, lithium difluorophosphate, lithium fluorosulfonate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium lower aliphatic carboxylate, lithium difluorodi(oxalato)phosphate, and lithium bis(fluorosulfonyl)imide.

[0024] The non-aqueous organic solvent includes at least one of chain carbonates, cyclic carbonates, and carboxylic acid esters. Further, the non-aqueous organic solvent is selected from at least one of γ-butyrolactone, γ-valerolactone, δ-valerolactone, methyl acetate, ethyl acetate, ethyl propionate, butyl acetate, propyl propionate, butyl propionate, ethylene carbonate, propylene carbonate, butyl carbonate, pentylenetene carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl n-propyl carbonate, ethyl n-propyl carbonate, propylene carbonate, 1,3-dioxolane, 1,4-dioxane, crown ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2-trifluoromethyltetrahydrofuran, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.

[0025] The additive includes compound A, the structural formula of which is shown in Formula 1. R1 is selected from fluorine, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C6 alkyl groups; R2, R3, and R4 are each independently selected from hydrogen, fluorine, substituted or unsubstituted alkoxy groups containing C1-C6, substituted or unsubstituted amino groups, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C6 alkyl groups; R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C6 alkyl groups.

[0026]

[0027] Formula 1 Furthermore, R1 is selected from fluorine, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups; R2, R3, and R4 are each independently selected from hydrogen, fluorine, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups; R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups. Even further, R1 is selected from substituted or unsubstituted aromatic groups; R2, R3, and R4 are each independently selected from hydrogen, and substituted or unsubstituted C1-C4 alkyl groups; R5, R6, and R7 are each independently selected from hydrogen, and substituted or unsubstituted C1-C4 alkyl groups. Wherein, substituted or unsubstituted aromatic groups refer to fluorine, alkyl, or fluoroalkyl-substituted aromatic groups, specifically fluorobenzene, methylbenzene, and fluorobenzyl. Substituted or unsubstituted C1-C6 alkyl groups refer to substituted or unsubstituted straight-chain or branched saturated hydrocarbon groups containing 1 to 6 carbon atoms. These can be methyl, ethyl, propyl (CH3CH2CH2-), butyl, isopropyl, butyl, pentyl, or hexyl. Substituted C1-C6 alkyl groups refer to alkyl groups in which one or more hydrogen atoms are replaced by other atoms or groups (called substituents). Substituents can be halogens (such as fluorine, chlorine, bromine, iodine), hydroxyl, amino, nitro, alkoxy, or aryl. For example, a methyl group can be substituted with a chlorine atom to form chloromethyl (-CH2Cl) or with a hydroxyl group to form hydroxymethyl (-CH2OH). Unsubstituted C1-C6 alkyl groups refer to alkyl groups in which no hydrogen atoms are replaced by other atoms or groups. Substituted or unsubstituted C1-C6 alkoxy groups refer to substituted or unsubstituted straight-chain or branched alkoxy groups containing 1 to 6 carbon atoms. Specifically, they can be methoxy or ethoxy. The substituted or unsubstituted amino group can be an amino group or one or two hydrogens can be substituted by a methyl or ethyl group.

[0028] Compound A is selected from at least one of compounds one through five.

[0029]

[0030] Compound 1 Compound 2 CAS:395061-59-3CAS:169179-88-8

[0031] Compound 3 Compound 4 CAS:402846-06-4 CAS:402846-08-6

[0032] Compound Five Compound 5 can be obtained by reacting chlorofluorosulfonyl (CAS:13637-84-8) with vinyloxazolone (CAS:1856-28-6), as shown in the following reaction.

[0033] In the synthesis of compound five, a catalyst and heating can be used to promote the reaction, and the catalyst can be a conventional nucleophilic substitution reaction catalyst, such as a basic catalyst.

[0034] The mass percentage of compound A is 0.05% to 5.00%, based on the mass of electrolyte salt, non-aqueous organic solvent, and additives as 100%. For example, the mass percentage of compound A may be, but is not limited to, 0.05%, 0.10%, 0.30%, 0.50%, 0.70%, 1.00%, 1.30%, 1.50%, 1.70%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, and 5.00%, but is not limited to the listed values; other unlisted values ​​within this range also apply.

[0035] Furthermore, the electrolyte also includes additives. The mass percentage of the additives is 0.50% to 4.50% based on 100% of the mass of the electrolyte salt, non-aqueous organic solvent, and additives. Preferably, the mass percentage of the additives is 2.00% to 4.00%. For example, the mass percentage of the additives may be, but is not limited to, 0.05%, 0.10%, 0.30%, 0.50%, 0.70%, 1.00%, 1.30%, 1.50%, 1.70%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, and 4.50%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The additives may be selected from at least one of VC, PS, DTD, ES, and FEC.

[0036] To further illustrate the purpose, technical solution, and beneficial effects of this invention, the following will provide a further description of the invention in conjunction with specific embodiments. It should be noted that, for other raw materials in the embodiments and comparative examples where specific conditions are not specified, they can be carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used where the manufacturer is not specified are all commercially available conventional products.

[0037] Example 1 1.1 Preparation of Electrolyte In an argon atmosphere and a vacuum glove box with a moisture content of <1ppm, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and ethyl acetate (EA) were mixed in a weight ratio of EC:EMC:EA = 3:1:4 to prepare 81.5g of non-aqueous organic solvent. Then, 0.5g of compound one was added as an additive, dissolved, and stirred thoroughly. After that, 18.0g of lithium hexafluorophosphate was added and mixed evenly to obtain a non-aqueous electrolyte.

[0038] 1.2 Preparation of the positive electrode Lithium iron phosphate material LiFePO4, binder PVDF and conductive agent SuperP are mixed evenly at a mass ratio of 95:1:4 to prepare a lithium secondary battery positive electrode slurry with a certain viscosity. The mixed slurry is coated on both sides of aluminum foil, dried and rolled to obtain the positive electrode sheet.

[0039] 1.3 Preparation of the diaphragm Polyethylene (PE) with a thickness of approximately 15 μm is used as the separator.

[0040] 1.4 Preparation of the negative electrode A negative electrode graphite material, binder PVDF and conductive agent SuperP are mixed evenly at a mass ratio of 90:2:8 to prepare a lithium secondary battery negative electrode slurry with a certain viscosity. The mixed slurry is coated on both sides of copper foil, dried and rolled to obtain a negative electrode sheet.

[0041] 1.5 Preparation of Lithium Secondary Batteries The positive electrode, separator, and negative electrode are stacked in sequence, and then layered as needed. After the tabs are welded, the battery is placed in the aluminum-plastic film of the outer packaging. The prepared non-aqueous electrolyte is injected into the dried bare cell. Vacuum sealing, settling, formation and shaping, and capacity testing are then performed to obtain a 1Ah soft-pack lithium secondary battery.

[0042] The composition and content of the electrolytes in Examples 1-11 and Comparative Examples 1-3 are shown in Table 1. The preparation processes of the lithium-ion battery electrolytes, positive electrode sheets, negative electrode sheets, and lithium-ion batteries in Examples 2-11 and Comparative Examples 1-3 are the same as those in Example 1.

[0043] Table 1. Composition of the electrolytes in Examples 1-11 and Comparative Examples 1-3

[0044] The structural formulas of compounds six and seven are shown below.

[0045]

[0046] Compound 6 Compound 7 The lithium-ion batteries prepared in Examples 1-11 and Comparative Examples 1-3 were subjected to performance tests under the following conditions, and the results are shown in Table 2.

[0047] (1) High-temperature cycling performance test The lithium-ion battery was placed in a 45°C constant temperature chamber and left to stand for 30 minutes to reach a constant temperature. It was then charged at a constant current of 5C until the voltage reached 3.65V, followed by constant voltage charging at 3.65V until the current reached 0.05C. Next, it was discharged at a constant current of 5C until the voltage reached 2.5V. The first discharge capacity was recorded as C0, constituting one charge-discharge cycle. Then, 1400 cycles of 2C / 2C charge and discharge were performed at 45°C, with the discharge capacity recorded as C1. The capacity retention rate of the lithium-ion battery was calculated using the following formula.

[0048] Capacity retention rate = C1 / C0 × 100% (2) AC impedance performance test The lithium-ion battery was placed in a 25°C constant temperature chamber and left to stand for 30 minutes to reach a constant temperature. It was then charged at a constant current of 0.33 C until the voltage reached 3.65V, followed by a constant voltage charge of 3.65V until the current reached 0.05C. Next, it was discharged at a constant current of 0.33C until the voltage reached 2.5V. The first discharge capacity was recorded as 100% SOC. The battery was then charged again at a constant current of 0.33C until the voltage reached 3.65V, followed by a constant voltage charge of 3.65V until the current reached 0.05C. Finally, it was discharged at a constant current of 0.33C until 50% SOC was reached. The electrochemical impedance spectroscopy (EIS) was measured using an electrochemical workstation with an open-circuit voltage, an amplitude of 10mV, and a frequency range of 0.01Hz to 1000000Hz.

[0049] Table 2 Performance test results of lithium-ion batteries in Examples 1-11 and Comparative Examples 1-3

[0050] As shown in Table 2, compared to Comparative Examples 1-3, the additives in Examples 1-11, including Compound A, which has a sulfonyl-vinylazolidinone structure, can significantly reduce the charge transfer resistance of the battery and improve its high-temperature cycling performance. After 1400 cycles at 45°C, it still maintains over 88% capacity retention. Comparative Example 2 uses Compound VI as an additive, which has a high carbonyl group and high viscosity, making cycling difficult. Comparative Example 3 uses Compound VII as an additive, which has an active hydrogen atom on its sulfonamide, easily generating HF, corroding the SEI film, and thus deteriorating performance.

[0051] Comparing Examples 1-5, it can be seen that the battery performance is better when R1 is substituted or unsubstituted F. This is because F can form SEI such as LiF with Li during the formation stage, which is conducive to lithium ion transport, and thus has better performance.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A non-aqueous electrolyte, characterized in that, It includes an electrolyte salt, a non-aqueous organic solvent, and an additive, wherein the additive includes compound A, the structural formula of which is shown in Formula 1. Formula 1 Wherein, R1 is selected from fluorine, substituted or unsubstituted aromatic groups, substituted or unsubstituted C1-C6 alkyl groups; R2, R3, and R4 are each independently selected from hydrogen, fluorine, substituted or unsubstituted alkoxy groups containing C1-C6, substituted or unsubstituted amino groups, substituted or unsubstituted aromatic groups, substituted or unsubstituted C1-C6 alkyl groups; and R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted aromatic groups, substituted or unsubstituted C1-C6 alkyl groups.

2. The non-aqueous electrolyte according to claim 1, characterized in that, R1 is selected from fluorine, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups; R2, R3, and R4 are each independently selected from hydrogen, fluorine, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups; R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted aromatic groups, and substituted or unsubstituted C1-C4 alkyl groups.

3. The non-aqueous electrolyte according to claim 1, characterized in that, R1 is selected from substituted or unsubstituted aromatic groups, R2, R3, and R4 are each independently selected from hydrogen, substituted or unsubstituted C1-C4 alkyl groups, and R5, R6, and R7 are each independently selected from hydrogen, substituted or unsubstituted C1-C4 alkyl groups.

4. The non-aqueous electrolyte according to claim 1, characterized in that, Compound A is selected from at least one of compounds one through five. Compound 1 Compound 2 Compound 3 Compound 4 Compound 5.

5. The non-aqueous electrolyte according to claim 1, characterized in that, Based on the mass of the electrolyte salt, the non-aqueous organic solvent, and the additive being 100%, the mass percentage of compound A is 0.05~5.00%.

6. The non-aqueous electrolyte according to claim 1, characterized in that, The electrolyte salt is a lithium salt, which is selected from at least one of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(oxalate-borate), lithium difluorophosphate, lithium fluorosulfonate, lithium bis(oxalate-borate), lithium difluorooxalate-borate, lithium lower aliphatic carboxylic acids, lithium difluorobis(oxalate-phosphate), and lithium bis(oxalate-imide).

7. The non-aqueous electrolyte according to claim 1, characterized in that, The non-aqueous organic solvent is selected from at least one of γ-butyrolactone, γ-valerolactone, δ-valerolactone, methyl acetate, ethyl acetate, ethyl propionate, butyl acetate, propyl propionate, butyl propionate, ethylene carbonate, propylene carbonate, butyl carbonate, pentylenetene carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl n-propyl carbonate, ethyl n-propyl carbonate, propylene carbonate, 1,3-dioxolane, 1,4-dioxane, crown ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2-trifluoromethyltetrahydrofuran, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.

8. A lithium-ion battery, comprising a positive electrode material, a negative electrode material, and an electrolyte, characterized in that, The electrolyte is selected from the non-aqueous electrolyte described in any one of claims 1 to 7.

9. The lithium-ion battery according to claim 8, characterized in that, The cathode material is selected from at least one of lithium iron phosphate materials, lithium manganese iron phosphate materials, lithium nickel cobalt manganese oxide materials, lithium nickel cobalt aluminum oxide materials, and lithium cobalt oxide materials.

10. The lithium-ion battery according to claim 8, characterized in that, The negative electrode material is selected from at least one of artificial graphite, natural graphite, lithium titanate, silicon-carbon composite material, and silicon-oxygen composite material.

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