Non-aqueous electrolyte and lithium ion battery

Abstract

The application provides a nonaqueous electrolyte and a lithium ion battery. The nonaqueous electrolyte comprises an electrolyte salt, a nonaqueous organic solvent and an additive. The additive comprises a compound A shown in structural formula I or structural formula II, wherein X, Y and Z are each independently selected from C, S and P-R, m, n and p are each independently 0 or 1, R1, R2 and R3 are each independently selected from hydrogen, fluorine, C1-C4 alkyl or fluorine-substituted C1-C4 alkyl, and R is selected from fluorine, C1-C4 alkyl or fluorine-substituted C1-C4 alkyl. The nonaqueous electrolyte contains the compound A, and the use of the compound A in the lithium ion battery can improve the high-temperature and low-temperature performance of the battery, and the rapid migration of ions under fast charging conditions, so that the high capacity and fast charging of the secondary battery can be met. Structural formula I Structural formula II

Description

Technical Field

[0001] This invention belongs to the field of new energy battery technology, and particularly relates to a non-aqueous electrolyte and a lithium-ion battery. Background Technology

[0002] Rechargeable batteries, as a type of green and environmentally friendly high-energy battery, are currently the most ideal and promising rechargeable batteries in the world. Lithium-ion batteries, in particular, possess a series of advantages compared to other batteries, including no memory effect, rapid charging and discharging, high energy density, long cycle life, and no environmental pollution. Therefore, they are widely used in small electronic devices such as laptops, cameras, mobile phones, and smartwatches, as well as large-scale power transmission equipment such as electric vehicles and energy storage systems. Currently, with the increasing demands on lithium-ion battery capacity from pure electric vehicles, hybrid vehicles, and portable energy storage devices, there is a growing expectation for the development of lithium-ion batteries with fast charging capabilities and high capacity to improve the convenience of people's lives.

[0003] Currently, the industry is increasing the charging current to improve the charging speed of lithium-ion batteries. However, this increased charging speed leads to localized lithium deposition. Simultaneously, because the rate of lithium ion insertion into graphite is lower than the rate of lithium ion migration, a large amount of lithium accumulates, further exacerbating lithium ion deposition and easily forming lithium dendrites. These lithium dendrites cause continuous decomposition and regeneration at the electrode-electrolyte interface, leading to continuous electrolyte consumption and ultimately deteriorating lithium-ion battery performance.

[0004] Therefore, how to provide a lithium-ion battery with good overall performance is a technical problem that urgently needs to be solved. 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. The non-aqueous electrolyte contains compound A, which, when used in a lithium-ion battery, can improve the battery's high-temperature and low-temperature performance, as well as the rapid migration of ions under fast charging conditions, thus meeting the requirements of high capacity and fast charging for secondary batteries.

[0006] To achieve the above objectives, the present invention provides a non-aqueous electrolyte. The non-aqueous electrolyte comprises an electrolyte salt, a non-aqueous organic solvent, and an additive. The additive comprises compound A as shown in structural formula I or structural formula II, wherein X, Y, and Z are each independently selected from C, S, and PR; m, n, and p are each independently 0 or 1; R1, R2, and R3 are each independently selected from hydrogen, fluorine, C1-C4 alkyl groups, or fluorine-substituted C1-C4 alkyl groups; and R is selected from fluorine, C1-C4 alkyl groups, or fluorine-substituted C1-C4 alkyl groups.

[0007]

[0008] Structural Formula I Structural Formula II The non-aqueous electrolyte of this invention contains compound A, a multi-five-membered ring compound with relatively suitable oxidation and reduction potentials. Its low potential allows it to be oxidized before the solvent, forming a thin interfacial layer on the electrode surface. This reduces ion transport pathways and improves gas generation at high voltages. Its high-potential oxidation resistance protects the solvent from oxidative decomposition, reducing electrolyte side reactions and stabilizing the electrolyte-electrode interface. More importantly, the multi-five-membered ring compound containing amino groups and intracyclic carboxylic esters (carbonates, sulfonates, or phosphates) forms an interfacial component rich in nitrogen, sulfur, and phosphorus on the electrode surface. This interfacial component exhibits superior ion transport efficiency and high-temperature stability, supporting lithium-ion transport and migration under extreme conditions. Furthermore, the relatively dense and moderately thick interface formed by the multi-five-membered ring structure is highly beneficial for improving the stability of the electrode interface under extreme conditions (high and low temperatures, high voltage). Therefore, its use in secondary batteries can improve the high and low temperature performance and fast-charging performance of the battery.

[0009] As a technical solution of the present invention, R1 and R2 are each independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl or trifluoroethyl, and R is selected from fluorine.

[0010] As a technical solution of the present invention, compound A is selected from at least one of compounds one to eight.

[0011]

[0012] Compound 1, Compound 2, Compound 3, Compound 4

[0013] Compound 5, Compound 6, Compound 7, Compound 8 As one technical solution of the present invention, the mass percentage of compound A in the non-aqueous electrolyte is 0.1~5.0%.

[0014] As one technical solution of the present invention, the electrolyte salt is selected from at least one of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium methanesulfonate, lithium trifluoromethanesulfonate, lithium fluorosulfonate, lithium dioxalateborate, lithium difluorooxalateborate, lithium difluorophosphate, lithium difluorobis(oxalate)phosphate, lithium bis(fluorosulfonyl)imide, lithium diphosphate, and lithium lower aliphatic carboxylic acids.

[0015] As one technical solution of the present invention, the electrolyte salt accounts for 5 to 25% of the total mass of the non-aqueous electrolyte.

[0016] As a technical solution of the present invention, the non-aqueous organic solvent is selected from at least one of carbonate compounds, carboxylic acid ester compounds, and ether compounds.

[0017] As one technical solution of the present invention, the non-aqueous organic solvent is selected from at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, propyl propionate, butyl propionate, 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.

[0018] A second aspect of the present invention provides a lithium-ion battery, comprising a positive electrode material, a negative electrode material, and the aforementioned non-aqueous electrolyte.

[0019] As one technical solution of the present invention, the cathode material comprises LiNi x Co y Mn z M 1-x-y-z O2 or LiNi x Co y Al z M 1-x-y-z O2, where M is any one of Mg, Cu, Zn, Sn, B, Ga, Cr, Sr, V, and Ti, 0.5 ≤ x < 1.0, 0 <y<1.0,0<z<1.0,0.9<x+y+z≤1.0。 Detailed Implementation

[0020] The non-aqueous electrolyte of this invention can improve the high and low temperature performance and fast charging performance of lithium-ion batteries. The lithium-ion battery of this invention may include a positive electrode material, a negative electrode material, and a non-aqueous electrolyte. The positive electrode material may be a material capable of ion intercalation and deintercalation with lithium ions. Preferably, the positive electrode material comprises LiNi. x Co y Mn z M 1-x-y-z O2 or LiNi x Co y Al z M 1-x-y-zO2, wherein M is any one of Mg, Cu, Zn, Sn, B, Ga, Cr, Sr, V, and Ti, 0.5 ≤ x < 1.0, 0 < y < 1.0, 0 < z < 1.0, 0.9 < x + y + z ≤ 1.0. The negative electrode material is selected from at least one of carbon-based negative electrode materials, titanium-based oxide negative electrode materials, and alloy-based negative electrode materials. The negative electrode material includes at least one of a carbon-based negative electrode, a silicon-based negative electrode, a tin-based negative electrode, and a lithium negative electrode. The carbon-based negative electrode may include graphite, hard carbon, soft carbon, graphene, mesocarbon microbeads, etc. The silicon-based negative electrode may include silicon materials, silicon oxides, silicon-carbon composite materials, and silicon alloy materials, etc. The tin-based negative electrode may include tin, tin-carbon, tin-oxygen, tin metal compounds. The lithium negative electrode may include metallic lithium or a lithium alloy. The lithium alloy may specifically be at least one of a lithium-silicon alloy, a lithium-sodium alloy, a lithium-potassium alloy, a lithium-aluminum alloy, a lithium-tin alloy, and a lithium-indium alloy.

[0021] The non-aqueous electrolyte includes an electrolyte salt, a non-aqueous organic solvent, and an additive.

[0022] The mass ratio of the electrolyte salt in the non-aqueous electrolyte is 5% to 25%. Further, the mass ratio of the electrolyte salt in the non-aqueous electrolyte is 6% to 20%. More specifically, the mass ratio is 8% to 18%. By way of example, the mass ratio of the electrolyte salt may 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 numerical range are equally applicable. The electrolyte salt is selected from at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium methanesulfonate (LiCH3SO3), lithium trifluoromethanesulfonate (LiCF3SO3), lithium fluorosulfonate (LiSO2F), lithium bis(oxalato)borate (LiBC4O8), lithium difluoro(oxalato)borate (LiBF2C2O4), lithium difluorophosphate (LiPO2F2), lithium difluoro(bis(oxalato))phosphate (LiDFBP), lithium diphosphate (LiPO2F2), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), and lithium lower aliphatic carboxylate. Further, the lithium lower aliphatic carboxylate includes, but is not limited to, lithium chloroborane, lithium tetraphenylborate, lithium imide salts, etc.

[0023] The non-aqueous organic solvent is selected from at least one of carbonate compounds, carboxylic acid ester compounds, and ether compounds. Further, carbonate compounds include, but are not limited to, cyclic carbonates and chain carbonates. Cyclic carbonates may be, but are not limited to, ethylene carbonate (EC), propylene carbonate, butyl carbonate (BC), amyl carbonate, vinyl carbonate (VC), or derivatives thereof. Chain carbonates include, but are not limited to, dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and propylene carbonate (PC). Carboxylic acid ester compounds include, but are not limited to, cyclic carboxylic acid esters and chain carboxylic acid esters. Cyclic carboxylic acid esters may specifically include, but are not limited to, at least one of γ-butyrolactone, γ-valerolactone, and δ-valerolactone. Chain carboxylic acid esters include, but are not limited to, at least one of methyl acetate (MA), ethyl acetate (EA), propyl acetate (EP), butyl acetate, propyl propionate (PP), and butyl propionate. Ether compounds include cyclic ethers or chain ethers. Cyclic ethers include, but are not limited to, at least one of 1,3-dioxolane (DOL), 1,4-dioxolane (DX), crown ethers, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-CH3-THF), and 2-trifluoromethyltetrahydrofuran (2-CF3-THF). Chain ethers include, but are not limited to, at least one of dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.

[0024] The additive includes compound A as shown in structural formula I or structural formula II, wherein X, Y, Z are each independently selected from C, S, PR, m, n, and p are each independently 0 or 1, R1, R2, and R3 are each independently selected from hydrogen, fluorine, C1-C4 alkyl or fluorine-substituted C1-C4 alkyl, and R is selected from fluorine, C1-C4 alkyl or fluorine-substituted C1-C4 alkyl.

[0025]

[0026] Structural Formula I Structural Formula II Furthermore, R1 and R2 are each independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, or trifluoroethyl, and R is selected from fluorine. As an example, R1 and R2 are each independently selected from hydrogen, fluorine, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, monofluoromethyl, monofluoroethyl, monofluoropropyl, monofluoroisopropyl, monofluorobutyl, monofluoroisobutyl, polyfluoromethyl, polyfluoroethyl, polyfluoropropyl, polyfluoroisopropyl, polyfluorobutyl, and polyfluoroisobutyl.

[0027] Furthermore, compound A is selected from at least one of compounds one through eight.

[0028]

[0029] Compound 1, Compound 2, Compound 3, Compound 4

[0030] Compound 5, Compound 6, Compound 7, Compound 8 Compounds one through eight can be synthesized in the following manner.

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039] The mass percentage of compound A in the non-aqueous electrolyte is 0.1% to 5.0%, further, the mass percentage of compound A in the non-aqueous electrolyte is 0.5% to 3.0%, and even further, the mass percentage is 0.5% to 1.5%. As an example, the mass percentage of compound A may be, but is not limited to, 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, and 5.0%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0040] 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 raw materials in the embodiments and comparative examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer can be followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available conventional products.

[0041] Example 1 (1) Preparation of electrolyte In a nitrogen-filled glove box (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed thoroughly in a mass ratio of 2:1:5:2 to obtain a mixed solvent, which was then used as an organic solvent. Compound 1 was added to obtain a mixed solution. The mixed solution was sealed and packaged and frozen in a freezer (-4°C) for 2 hours. After being removed, lithium hexafluorophosphate was slowly added to the mixed solution in a nitrogen-filled glove box (O2 < 1 ppm, H2O < 1 ppm) and mixed thoroughly to obtain an electrolyte.

[0042] (2) Preparation of positive electrode sheet Ternary material LiNi 0.8 Co 0.1 Mn 0.1 Zr 0.03 O2, conductive agent SuperP, binder PVDF, and carbon nanotubes (CNTs) were mixed uniformly in a mass ratio of 96.5:1.5:1:1 to prepare a lithium-ion battery positive electrode slurry of a certain viscosity. This slurry was then coated onto aluminum foil used as a current collector, with a coating weight of 324 g / m². 2 After drying at 85℃, the material is cold-pressed; then it is trimmed, cut into pieces, and slit. After slitting, it is dried at 85℃ for 4 hours under vacuum conditions, and then the tabs are welded to produce a lithium-ion battery positive electrode sheet that meets the requirements.

[0043] (3) Preparation of negative electrode sheet Artificial graphite and silicon are mixed at a mass ratio of 90:10, and then mixed with conductive agent SuperP, thickener CMC, and binder SBR (styrene-butadiene rubber latex) at a mass ratio of 95:1.5:1.0:2.5 to form a slurry. After being mixed evenly, the slurry is coated on both sides of copper foil, dried, and rolled to obtain a negative electrode sheet, thus producing a lithium-ion battery negative electrode sheet that meets the requirements.

[0044] (4) Preparation of lithium-ion batteries The positive electrode, negative electrode, and separator prepared according to the above process are stacked to form a lithium-ion battery with a thickness of 4.7 mm, a width of 55 mm, and a length of 60 mm. The battery is then vacuum-baked at 75°C for 10 hours and injected with the above-mentioned electrolyte. After standing for 24 hours, it is charged to 4.45V with a constant current of 0.1C (180 mA), and then charged at a constant voltage of 4.45V until the current drops to 0.05C (90 mA). It is then discharged to 3.0V at 0.2C (180 mA), and this charge-discharge cycle is repeated twice. Finally, the battery is charged to 3.8V at 0.2C (180 mA) to complete the fabrication of the lithium-ion battery.

[0045] The composition and content of the electrolytes in Examples 1-13 and Comparative Examples 1-2 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 1-13 and Comparative Examples 1-2 are the same as those in Example 1.

[0046] Table 1. Composition of the electrolytes in Examples 1-13 and Comparative Examples 1-2

[0047] The structural formula of compound nine in Table 1 above is shown below.

[0048]

[0049] Compound Nine The lithium-ion batteries using the electrolytes of Examples 1-13 and Comparative Examples 1-2 were subjected to high-temperature storage performance tests, high-temperature cycle performance tests, room-temperature fast-charge cycle performance tests, and low-temperature performance tests. The results are shown in Table 2.

[0050] (1) High-temperature storage performance test Under normal temperature (25℃) conditions, the lithium-ion battery was subjected to one 0.5C / 0.5C charge and discharge cycle (battery discharge capacity recorded as C0), with an upper limit voltage of 4.4V. Then, the battery was charged to 4.4V under constant current and constant voltage conditions at 0.5C, and the battery thickness was measured (thickness recorded as D0). The battery was placed in a 60℃ oven for 30 days, removed, and the battery thickness was measured (thickness recorded as D1). The battery was placed in a 25℃ environment and discharged at 0.5C (discharge capacity recorded as C1). The lithium-ion battery was then subjected to one more 0.5C / 0.5C charge and discharge cycle under normal temperature (25℃) conditions (battery discharge capacity recorded as C2), with an upper limit voltage of 4.4V. The capacity retention rate, capacity recovery rate, and thickness expansion rate were calculated.

[0051] Capacity retention rate = (C1 / C0) * 100% Capacity recovery rate = (C2 / C0) * 100% Thickness expansion rate = (D1 / D0) * 100% (2) Room temperature cycling performance test Under normal temperature (25℃) conditions, a lithium-ion battery is subjected to one 1.0C / 1.0C charge and discharge cycle (battery discharge capacity is C0), with an upper limit voltage of 4.4V. Then, under normal temperature conditions, it is subjected to 500 cycles of 4.0C / 1.0C charge and discharge (battery discharge capacity is C1). Calculate the capacity retention rate.

[0052] Capacity retention rate = (C1 / C0) * 100% (3) High temperature cycling test Under high temperature (45℃) conditions, a lithium-ion battery is subjected to one 1.0C / 1.0C charge and discharge cycle (battery discharge capacity is C0), with an upper limit voltage of 4.4V. Then, it is subjected to 400 cycles of 1.0C / 1.0C charge and discharge at room temperature (battery discharge capacity is C1). The capacity retention rate is calculated.

[0053] Capacity retention rate = (C1 / C0) * 100% (4) Low temperature performance test Under normal temperature (25℃) conditions, a lithium-ion battery is subjected to a single 0.5C / 0.5C charge-discharge cycle (battery cutoff voltage 3.0V, discharge capacity C0), with an upper limit voltage of 4.4V (cutoff current 0.05C). Then, the battery is fully charged to 4.4V at 0.5C (cutoff current 0.05C) at normal temperature (25℃), and then transferred to -20℃ for 4 hours. It is then discharged at 0.5C to 3.0V, with a discharge capacity of C1. The capacity retention rate is calculated.

[0054] Capacity retention rate = (C1 / C0) * 100% Table 2 Test results of lithium-ion battery performance

[0055] As shown in Table 2, the overall performance of Examples 1-13 is better than that of Comparative Examples 1-2. This is because the electrolytes of Examples 1-13 contain compound A, which is a multi-five-membered ring compound with relatively suitable oxidation and reduction potentials. Its low potential characteristic allows it to be oxidized before the solvent, forming a thin interface layer on the electrode surface, reducing the ion transport path and improving the gas generation problem of the battery under high voltage. Its high potential oxidation resistance can protect the solvent from oxidative decomposition, reduce the occurrence of electrolyte side reactions, and stabilize the electrolyte electrode interface. More importantly, the multi-five-membered ring compound containing amino groups and intracyclic carboxylic esters (carbonates, sulfonates, or phosphates) can form an interface component rich in nitrogen, sulfur, phosphorus, and other elements on the electrode surface. This interface component has superior ion transport efficiency and high-temperature stability, supporting the transport and migration of lithium ions under extreme conditions. In addition, the interface formed by the multi-five-membered ring structure is relatively dense and of moderate thickness, which is very beneficial to improving the stability of the electrode interface under extreme conditions (high and low temperatures, high voltage).

[0056] In contrast, Compound IX in Comparative Example 2, although containing elements such as fluorine, sulfur, and nitrogen, can form a low-impedance SEI, may form acidic substances at high temperatures, leading to SEI rupture and recombination, gas production inside the battery, and thus poor performance.

[0057] The comparison of Examples 1-8 shows that the battery containing Compound VI has better high-temperature performance. This may be because Compound VI has a moderate proportion of sulfur and phosphorus elements, resulting in a sulfur- and phosphorus-rich interface with better thermal stability.

[0058] 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 comprising an electrolyte salt, a non-aqueous organic solvent, and an additive, said additive comprising compound A as shown in structural formula I or II, wherein, X, Y, and Z are each independently selected from C, S, and PR; m, n, and p are each independently 0 or 1; R1, R2, and R3 are each independently selected from hydrogen, fluorine, C1-C4 alkyl groups, or fluorine-substituted C1-C4 alkyl groups; R is selected from fluorine, C1-C4 alkyl groups, or fluorine-substituted C1-C4 alkyl groups. Structural Formula I and Structural Formula II.

2. The non-aqueous electrolyte according to claim 1, characterized in that, R1 and R2 are each independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl or trifluoroethyl, and R is selected from fluorine.

3. The non-aqueous electrolyte according to claim 1, characterized in that, Compound A is selected from at least one of compounds one through eight. Compound 1, Compound 2, Compound 3, Compound 4 Compound 5, Compound 6, Compound 7, Compound 8.

4. The non-aqueous electrolyte according to claim 1, characterized in that, The mass percentage of compound A in the non-aqueous electrolyte is 0.1-5.0%.

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

6. The non-aqueous electrolyte according to claim 1, characterized in that, The electrolyte salt accounts for 5-25% of the total mass of the non-aqueous electrolyte.

7. The non-aqueous electrolyte according to claim 1, characterized in that, The non-aqueous organic solvent is selected from at least one of carbonate compounds, carboxylic acid ester compounds, and ether compounds.

8. The non-aqueous electrolyte according to claim 7, characterized in that, The non-aqueous organic solvent is selected from at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, propyl propionate, butyl propionate, 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.

9. A lithium-ion battery, characterized in that, It includes positive electrode materials, negative electrode materials, and the non-aqueous electrolyte as described in any one of claims 1 to 8.

10. The lithium-ion battery according to claim 9, characterized in that, The cathode material includes LiNi. x Co y Mn z M 1-x-y-z O2 or LiNi x Co y Al z M 1-x-y-z O2, where M is any one of Mg, Cu, Zn, Sn, B, Ga, Cr, Sr, V, and Ti, 0.5 ≤ x < 1.0, 0 <y<1.0,0<z<1.0,0.9<x+y+z≤1.0。

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