Electrolyte and lithium ion battery

Abstract

The electrolyte comprises an electrolyte salt, a non-aqueous organic solvent and an additive, the additive comprises a compound A shown as a structural formula 1, X is selected from carbon, sulfur or phosphorus, R1 is selected from C1-C6 alkyl, m, n and z are respectively and independently 0 or 1, and m + n = 0 or 1. According to the electrolyte, the lithium ion battery can simultaneously meet relatively good high-temperature storage, high-temperature circulation, normal-temperature quick charge circulation performance and low-temperature performance.

Description

Technical Field

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

[0002] In recent years, lithium-ion batteries have made significant progress in energy density, cycle life, and cost control, and are widely used in electric vehicles, consumer electronics, and energy storage systems. The optimization of high-nickel ternary (NCM / NCA) and lithium iron phosphate (LFP) cathode materials, the gradual commercialization of silicon-carbon composite anodes, and the development of novel electrolyte systems have significantly improved the energy density and cycle life of lithium-ion batteries. However, with the diversification of application scenarios, higher demands are being placed on battery stability under extreme temperatures, fast charging capabilities, and wide temperature range adaptability. Currently, the performance of commercially available lithium-ion batteries is still limited by the inherent contradictions in the material systems, making it difficult to simultaneously meet the requirements of high-temperature storage, high-temperature cycling, room-temperature fast charging, and low-temperature performance.

[0003] The core reason why existing technologies struggle to achieve synergistic optimization of multiple performance characteristics lies in the inherent conflicts within the material systems. For example: electrolyte design contradictions: high-temperature stable electrolytes (such as sulfone-containing / ionic liquids) typically exhibit poor low-temperature fluidity, while low-temperature suitable solvents (such as carboxylic esters) are prone to volatility or oxidation at high temperatures. Interface stability conflicts: high-temperature stable SEI films (such as those rich in LiF) may hinder low-temperature Li... + Transmission is problematic, but the thin SEI film (low impedance) required for fast charging is prone to failure at high temperatures. Electrode material limitations: high-nickel cathodes can improve energy density, but have poor high-temperature stability; silicon-based anodes can improve rate performance, but have short cycle life.

[0004] Therefore, there is an urgent need for an electrolyte and lithium-ion battery to address the shortcomings of existing technologies. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide an electrolyte and a lithium-ion battery, wherein the electrolyte enables the lithium-ion battery to simultaneously meet good high-temperature storage, high-temperature cycling, room-temperature fast-charge cycling performance and low-temperature performance.

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

[0007] Formula 1 Wherein, X is selected from carbon, sulfur or phosphorus, R1 is selected from C1~C6 alkyl, m, n and z are each independently 0 or 1, and m+n=0 or 1.

[0008] Compared with existing technologies, the electrolyte of the present invention contains compound A as shown in Formula 1. Compound A is a polycyclic compound with relatively low oxidation and reduction potentials. Its low potential characteristic allows it to be oxidized before the solvent, forming a thin interfacial layer on the electrode surface. This reduces the ion transport path and significantly improves the high-temperature cycle performance, room-temperature fast-charge cycle performance, and low-temperature performance of lithium-ion batteries. Furthermore, the nitrogen-containing heterocycle shown in Formula 1 exhibits Lewis basicity, which can scavenge hydrogen radicals in the electrolyte, inhibit the increase of electrolyte acid value, and improve gas generation during storage. In summary, the electrolyte of the present invention enables lithium-ion batteries to simultaneously meet the requirements of good high-temperature storage, high-temperature cycling, room-temperature fast-charge cycle performance, and low-temperature performance.

[0009] Furthermore, compound A of the present invention is selected from at least one of compounds 1 to 8:

[0010]

[0011] Specifically, compounds 1 through 8 can be prepared by following the synthetic route:

[0012]

[0013]

[0014]

[0015]

[0016]

[0017] Furthermore, the mass percentage of compound A in the electrolyte is 0.1% to 5%. As an example, the mass of compound A accounts for 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, and 5.0% of the total mass of the electrolyte, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0018] Further, the electrolyte salt of the present invention includes at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium methanesulfonate (LiCH3SO3), lithium trifluoromethanesulfonate (LiCF3SO3), lithium fluorosulfonate (LiSO2F), lithium di(oxalato)borate (LiBC4O8), lithium di(fluorooxalato)borate (LiBF2C2O4), lithium difluorophosphate (LiPO2F2), lithium di(fluorobis(oxalato)borate) (LiDFBP), lithium diphosphate (LiPO2F2), lithium trifluoromethanesulfonyl)imide (LiTFSI), and lower aliphatic carboxylic acids. Further, lower aliphatic carboxylic acids include, but are not limited to, lithium chloroborane, lithium tetraphenylborate, and lithium imide salts.

[0019] Further, the mass of the electrolyte salt of the present invention accounts for 5-25% of the total mass of the electrolyte. Further, the mass of the electrolyte salt accounts for 6-20% of the total mass of the electrolyte, preferably 8-18% of the total mass of the electrolyte. As examples, the mass of the electrolyte salt accounts for 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, and 24% of the total mass of the electrolyte, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0020] Further, the non-aqueous organic solvent of the present invention includes at least one of carbonates, carboxylic esters, and ether compounds. Further, carbonates 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 esters include, but are not limited to, cyclic carboxylic esters and chain carboxylic esters. Cyclic carboxylic esters may specifically include, but are not limited to, at least one of γ-butyrolactone, γ-valerolactone, and δ-valerolactone. Chain carboxylic 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.

[0021] Furthermore, the electrolyte of the present invention further includes additives selected from vinylene carbonate (VC), vinylene carbonate (VEC), fluoroethylene carbonate (FEC), vinyl sulfite (ES), 1,3-propanesulfonate lactone (PS), 1,3-propenesulfonate lactone (PES), 1,4-butanesulfonate lactone (BS), vinyl sulfate (DTD), succinic anhydride (SA), maleic anhydride (MA), 2-methylmaleic anhydride, methyl carbonate-2-propynyl ester, tetraethylenesilane, and triallyl isocyanurate. The battery contains at least one of the following: ester, hexamethylene diisocyanate, o-phenanthroline, terephthalic diisocyanate, 2,4-toluene diisocyanate, N-phenylbis(trifluoromethanesulfonyl)imide, vinyl disulfate, phenyl methanesulfonate, vinyl disulfate, dispironyl sulfate, hydroquinone difluorosulfonate, triallyl phosphate, triargyl phosphate, 2,4-butanesulfonyl lactone, isocyanoethyl methacrylate, methylene disulfonate, tri(trimethylsilane)borate, tri(trimethylsilane) phosphate, and tri(vinyldimethylsilane) phosphate. Through in-depth research, the inventors of this application have particularly preferred vinyl sulfate (DTD) as a key additive due to its unique film-forming properties: DTD can be preferentially reduced on the electrode surface to form an SEI film with both stability and high ionic conductivity. This film structure can significantly suppress electrolyte decomposition side reactions, thereby synergistically improving the battery's high-temperature storage performance, high-temperature cycle performance, and room-temperature fast-charging performance. It is worth noting that although DTD has low-temperature storage and transportation requirements when used alone (it is prone to discoloration at room temperature, which limits its application in the digital field), when compound A of the present invention is used in combination with DTD, it can significantly improve the discoloration problem of electrolyte at room temperature or high temperature. This is because the nitrogen-containing heterocyclic ring shown in Formula 1 can alleviate the increase of acid value in the electrolyte, thereby inhibiting the decomposition and discoloration of DTD. This synergistic effect breaks through the application limitations of traditional DTD additives and provides a new solution for the development of high-performance lithium-ion batteries.

[0022] Further, the mass of the additive of the present invention accounts for 0.1 to 5.0% of the total mass of the electrolyte, and further, the mass of the additive accounts for 0.2 to 2.0% of the total mass of the electrolyte. As an example, the mass of the additive accounts for 0.1%, 0.2%, 0.5%, 0.8%, 1.0%, 1.5%, 2.0%, 2.2%, 2.5%, 3.0%, 3.2%, 3.5%, 3.8%, 4.0%, 4.2%, 4.5%, 4.8%, and 5.0% of the total mass of the electrolyte, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0023] Accordingly, a second aspect of the present invention also provides a lithium-ion battery, including a positive electrode, a negative electrode, and the electrolyte mentioned above. This lithium-ion battery exhibits good high-temperature storage, high-temperature cycling, room-temperature fast-charge cycling performance, and low-temperature performance.

[0024] Further, the active material of the positive electrode of the present invention is 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. Preferably, the active material of the positive electrode is LiNi 0.8 Co 0.1 Mn 0.1 Zr 0.03 O2.

[0025] Further, the active material of the negative electrode of the present invention is selected from at least one of carbon-based negative electrodes, silicon-based negative electrodes, tin-based negative electrodes, and lithium negative electrodes. Among them, the carbon-based negative electrode may include graphite, hard carbon, soft carbon, graphene, mesophase carbon microspheres, 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, and tin metal compounds. The lithium negative electrode may include metallic lithium or lithium alloys. The lithium alloy may specifically be at least one of lithium-silicon alloy, lithium-sodium alloy, lithium-potassium alloy, lithium-aluminum alloy, lithium-tin alloy, and lithium-indium alloy. Preferably, the active material of the negative electrode is selected from silicon-carbon composite materials, and the silicon-carbon composite material includes artificial graphite and silicon. Specific Embodiments

[0026] In order to further illustrate the purpose, technical solution, and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that for those not specifying specific conditions in the embodiments and comparative examples, they can be carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specifying the manufacturer, they are all conventional products that can be obtained through commercial channels.

[0027] Example 1 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 1:1:3:4 to obtain a non-aqueous organic solvent. Compound 1 was then 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 (LiPF6) and lithium bis(fluorosulfonyl)imide (LiFSI) were slowly added to the mixed solution in a nitrogen-filled glove box (O2 < 1 ppm, H2O < 1 ppm). After thorough mixing, the electrolyte was prepared.

[0028] 1.2 Preparation of the positive electrode: 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 sheets, and slit. After slitting, it is dried at 85℃ for 4 hours under vacuum, and then the tabs are welded to produce a positive electrode sheet that meets the requirements.

[0029] 1.3 Preparation of the negative electrode: 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. The mixture is then coated on both sides of copper foil, dried, and rolled to form a negative electrode sheet that meets the requirements.

[0030] 1.4 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.

[0031] The composition and content of the electrolytes in Examples 1-21 and Comparative Examples 1-5 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 2-21 and Comparative Examples 1-5 are the same as those in Example 1. The additives were added along with the additives.

[0032] Table 1. Composition of the electrolytes in the examples and comparative examples

[0033] The structure of compound 9 is shown below:

[0034] Compound 9 The lithium-ion batteries prepared in Examples 1-21 and Comparative Examples 1-5 were subjected to high-temperature storage performance test, high-temperature cycle performance test, room-temperature fast-charge cycle performance test, and low-temperature performance test under the following conditions. The results are shown in Table 2.

[0035] 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.

[0036] Capacity retention rate = (C1 / C0) × 100% Capacity recovery rate = (C2 / C0) × 100% Thickness expansion rate = (D1 / D0) × 100% Room temperature fast charging cycle 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.

[0037] Capacity retention rate = (C1 / C0) × 100% High-temperature cycling performance 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.

[0038] Capacity retention rate = (C1 / C0) × 100% 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.

[0039] Capacity retention rate = (C1 / C0) × 100% Table 2 Test results of lithium-ion battery performance

[0040] Comparing Examples 1-8 with Comparative Example 1, it can be seen that the lithium-ion batteries of Examples 1-8 have superior high-temperature storage, high-temperature cycling, and room-temperature fast-charge cycling performance. This is because the electrolyte of the lithium-ion batteries of Examples 1-8 includes compound A, which is a polycyclic compound with relatively low 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 significantly improving the high-temperature cycling performance, room-temperature fast-charge cycling performance, and low-temperature performance of the lithium-ion battery. In addition, the nitrogen-containing heterocycle shown in Formula 1 exhibits Lewis basicity, which can scavenge hydrogen free radicals in the electrolyte, inhibit the increase of electrolyte acid value, and improve gas generation during storage. In summary, the electrolyte of the present invention enables lithium-ion batteries to simultaneously meet the requirements of good high-temperature storage, high-temperature cycling, room-temperature fast-charge cycling performance, and low-temperature performance.

[0041] Comparing Example 9 with Examples 15-18, it can be seen that adding an additive to the base containing compound A can further improve the high-temperature storage, high-temperature cycling, room-temperature fast-charging cycle performance and low-temperature performance of lithium-ion batteries.

[0042] The comparison between Examples 2 and 12-13 shows that the battery exhibits better overall electrochemical performance when LiPF6 and LiFSI are used together as electrolyte salts. This is because LiFSI has superior thermal stability and power characteristics, but it has a corrosion problem on the current collector. LiPF6 can passivate the current collector, thereby mitigating the negative impact of LiFSI on the current collector. When LiPF6 and LiFSI are used together, the battery performance is fully realized.

[0043] A comparison of Examples 15-16 and Examples 19-21 shows that when a VC / FEC mixed additive is used on the basis of a certain amount of compound A, the high-temperature performance and low-temperature performance of lithium-ion batteries can be significantly improved, and the expansion rate is further improved. This is because VC, FEC, and the structure of the present invention form a multi-component interface, which further improves the stability of the electrolyte electrode interface and the lithium-ion transport characteristics, resulting in a significant improvement in battery performance.

[0044] The comparison between Comparative Example 5 and Example 20 shows that the electrochemical performance of Compound 3 is better than that of Compound 9. This may be because Compound 9 has more double bonds than Compound 3, resulting in an excessively thick polymer layer for Compound 9, which leads to poor low-temperature and cycle performance of the battery.

[0045] A comparison of Examples 15-18 shows that, compared to other additives, DTD can preferentially reduce on the electrode surface to form an SEI film with both stability and high ionic conductivity. This film structure can significantly suppress electrolyte decomposition side reactions, thereby significantly improving the battery's high-temperature storage performance, high-temperature cycle performance, and room-temperature fast-charging performance. Therefore, DTD is preferably used as the additive.

[0046] Electrolyte high-temperature storage color change experiment: Electrolytes for Examples 1-1, 1-2, 1-3, 1-4, Comparative Example 1-1, and Comparative Example 1-2 were prepared according to the electrolyte formulations in Table 3. The initial color of the electrolytes for Examples 1-1, 1-2, 1-3, 1-4, Comparative Example 1-1, and Comparative Example 1-2 was then tested using a colorimetric method at 25°C. The electrolytes were then stored at 45°C for 72 hours, and the final color of the electrolytes was tested using a colorimetric method. The results are shown in Table 4.

[0047] Table 3 Electrolyte Formulation

[0048] Table 4 Initial and final color of electrolyte

[0049] As shown in Table 4, compared to compound 9, compounds 3 and 7 can improve the discoloration problem of the electrolyte. This may be because the nitrogen-containing heterocycle shown in Formula 1 can alleviate the increase in the acid value of the electrolyte, thereby inhibiting the decomposition and discoloration of DTD. However, the nitrogen-containing heterocycle shown in compound 9 is not easily stable under high temperature conditions and does not have a significant effect. This indicates that when compound A of the present invention is used in conjunction with DTD, it can significantly improve the discoloration problem of DTD-containing electrolytes at room temperature or high temperature.

[0050] 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. An electrolyte comprising an electrolyte salt, a non-aqueous organic solvent, and additives, characterized in that, The additive includes compound A as shown in structural formula 1. Formula 1 Wherein, X is selected from carbon, sulfur or phosphorus, R1 is selected from C1~C6 alkyl, m, n and z are each independently 0 or 1, and m+n=0 or 1.

2. The electrolyte as described in claim 1, characterized in that, Compound A is selected from at least one of compounds 1 to 8: 。 3. The electrolyte as described in claim 1, characterized in that, The mass percentage of compound A in the electrolyte is 0.1-5%.

4. The electrolyte as described in claim 1, characterized in that, The electrolyte salt includes at least one of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium difluorosulfonylimide, lithium bis(trifluoromethanesulfonylimide), lithium methanesulfonate, lithium trifluoromethanesulfonate, lithium fluorosulfonate, lithium dioxalate borate, lithium difluorooxalate borate, lithium difluorophosphate, lithium difluorobis(oxalate) phosphate, lithium difluorosulfonylimide, lithium diphosphate, and lithium lower aliphatic carboxylic acids.

5. The electrolyte as described in claim 1, characterized in that, The electrolyte salt accounts for 5-25% of the total mass of the electrolyte.

6. The electrolyte as described in claim 1, characterized in that, The non-aqueous organic solvent includes at least one of carbonates, carboxylic esters, and ether compounds.

7. The electrolyte as described in claim 1, characterized in that, It also includes additives selected from vinylene carbonate, vinylene ethylene carbonate, fluoroethylene carbonate, vinyl sulfite, 1,3-propanesulfonate lactone, 1,3-propenesulfonate lactone, 1,4-butanesulfonate lactone, vinyl sulfate, succinic anhydride, maleic anhydride, 2-methylmaleic anhydride, methyl carbonate-2-propynyl ester, tetraethylenesilane, triallyl isocyanurate, hexamethylene diisocyanate, o-phenanthroline, terephthalic diisocyanate, 2 At least one of the following: 4-toluene diisocyanate, N-phenylbis(trifluoromethanesulfonyl)imide, vinyl disulfate, phenyl methanesulfonate, vinyl disulfate, propylene dispironate, hydroquinone difluorosulfonate, triallyl phosphate, triargyl phosphate, 2,4-butane sulpholol, isocyanate ethyl methacrylate, methylene disulfonate, tri(trimethylsilane)borate, tri(trimethylsilane) phosphate, and tri(vinyldimethylsilane) phosphate.

8. A lithium-ion battery, comprising a positive electrode and a negative electrode, characterized in that, It also includes the electrolyte as described in any one of claims 1 to 7.

9. The lithium-ion battery as described in claim 8, characterized in that, The active material of the positive electrode is 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。 10. The lithium-ion battery as described in claim 8, characterized in that, The active material of the negative electrode is selected from at least one of carbon-based negative electrode, silicon-based negative electrode, tin-based negative electrode and lithium negative electrode.

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