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CN-115810795-B - Ternary high-nickel lithium ion battery nonaqueous electrolyte and lithium ion battery containing same

CN115810795BCN 115810795 BCN115810795 BCN 115810795BCN-115810795-B

Abstract

The invention belongs to the technical field of lithium ion batteries, and discloses a ternary high-nickel lithium ion battery nonaqueous electrolyte and a lithium ion battery containing the same. The ternary high-nickel lithium ion battery nonaqueous electrolyte comprises a nonaqueous organic solvent, electrolyte lithium salt and an additive, wherein the additive comprises a sulfur-containing additive and other film-forming additives, and the structure of the sulfur-containing additive is shown as a formula (I): According to the non-aqueous electrolyte of the high-nickel lithium ion battery, through optimizing the formula, under the combined action of multiple components in a unique combination, the electrolyte system has high energy density and long service life, and is beneficial to meeting the requirements of the electrolyte on the cycle performance and the high-temperature storage performance in the high-nickel system.

Inventors

  • FU XIANGTIAN
  • ZHU XUEQUAN
  • HUANG HUICONG
  • QIU YANG
  • ZHANG XIAOYU
  • ZHAO QIAN

Assignees

  • 杉杉新材料（衢州）有限公司

Dates

Publication Date
20260512
Application Date
20210914

Claims (7)

  1. 1. The ternary high-nickel lithium ion battery nonaqueous electrolyte is characterized by comprising a nonaqueous organic solvent, electrolyte lithium salt and an additive, wherein the additive comprises a sulfur-containing additive and other film-forming additives, and the sulfur-containing additive is selected from at least one of compounds shown in the following structural formulas: the mass percentage of the sulfur-containing additive in the ternary high nickel lithium ion battery nonaqueous electrolyte is 0.1-0.2%; The other film-forming additive comprises Vinylene Carbonate (VC), and at least one of lithium difluorooxalate borate (LiDFOB), methylene Methane Disulfonate (MMDS), vinyl sulfate (DTD) and lithium difluorobis-oxalate phosphate (LiDFOP); The electrolyte lithium salt is lithium hexafluorophosphate and lithium difluorosulfimide.
  2. 2. The ternary high nickel lithium ion battery nonaqueous electrolyte according to claim 1, wherein the mass percentage of the other film forming additives in the electrolyte is 0.2-2%.
  3. 3. The ternary high-nickel lithium ion battery nonaqueous electrolyte according to claim 1, wherein the mass percentage of the electrolyte lithium salt in the electrolyte is 12-18%.
  4. 4. The ternary high-nickel lithium ion battery nonaqueous electrolyte according to claim 1, wherein the nonaqueous organic solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, ethylmethyl carbonate, diethyl carbonate, and dimethyl carbonate.
  5. 5. A lithium ion battery, characterized in that the high nickel lithium ion battery comprises a positive electrode, a negative electrode, a diaphragm and the ternary high nickel lithium ion battery nonaqueous electrolyte of any one of claims 1-4.
  6. 6. The lithium ion battery of claim 5, wherein the active material of the positive electrode is LiNi1-x-yCoxMnyAlz, wherein x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 1, and x+y+z is more than or equal to 0 and less than or equal to 1, and the negative electrode material is one or more of natural graphite, artificial graphite, lithium titanate and silicon.
  7. 7. The lithium ion battery of claim 5, wherein the high nickel lithium ion battery has an upper cutoff voltage of 4.35-4.5V.

Description

Ternary high-nickel lithium ion battery nonaqueous electrolyte and lithium ion battery containing same Technical Field The invention relates to the technical field of lithium ion batteries, in particular to a ternary high-nickel lithium ion battery nonaqueous electrolyte and a lithium ion battery containing the same. Background With technological progress, people continuously increase the requirements on the quality of living environment, and the environmental pollution problem caused by the increasingly depleted and consumed fossil energy is more serious, so that the research and development of clean renewable new energy becomes urgent. A large amount of new energy sources such as solar energy, wind energy, tidal energy, geothermal energy and the like are developed and used at present, but the energy sources are limited in time and space and need to be properly converted and stored for use. The lithium ion battery is used as a green environment-friendly high-energy battery and is the most ideal and potential rechargeable battery in the world at present. Compared with other batteries, the battery has a series of advantages of no memory effect, rapid charge and discharge, high energy density, long cycle life, no environmental pollution and the like, and is widely applied to small electronic equipment such as notebook computers, video cameras, mobile phones, electronic watches and the like. With the continuous improvement of the capacity requirements of pure electric vehicles, hybrid electric vehicles, portable energy storage devices and the like on lithium ion batteries, the development of lithium ion batteries with higher energy density and power density is expected to realize long-term endurance and energy storage. The improvement of the nickel content in the positive electrode material of the battery can improve the energy density of the battery, but as the nickel content is improved, the stability of the positive electrode material is reduced, the circulation performance is deteriorated due to the increase of Ni, the thermal stability is deteriorated, the surface reaction is uneven in the charging and discharging process, the material is oxidized due to the existence of a large proportion of Ni4 + in the reaction product, the electrolyte is slowly oxidized, and the gas is discharged in the process, so that the development of the electrolyte suitable for a high-nickel system is needed. Disclosure of Invention The invention aims to overcome the defects of the background technology and provide a ternary high-nickel lithium ion battery nonaqueous electrolyte and a lithium ion battery containing the electrolyte. According to the non-aqueous electrolyte of the high-nickel lithium ion battery, through optimizing the formula, under the combined action of multiple components in a unique combination, the electrolyte system has high energy density and long service life, and is beneficial to meeting the requirements of the electrolyte on the cycle performance and the high-temperature storage performance in the high-nickel system. In order to achieve the purpose, the nonaqueous electrolyte of the ternary high-nickel lithium ion battery comprises a nonaqueous organic solvent, electrolyte lithium salt and additives, wherein the additives comprise sulfur-containing additives and other film-forming additives, and the structure of the sulfur-containing additives is shown as a formula (I): wherein R 1、R2、R3 is independently selected from a hydrogen atom, a fluorine atom, a nitrile group, a fluoroalkyl group, a silyl ether group, and a boron fluoride group; The other film forming additive is selected from at least one of Vinylene Carbonate (VC), fluoroethylene carbonate (FEC), vinyl vinylene carbonate (VEC), 1, 3-Propane Sultone (PS), propylene Sultone (PST), butylene Sultone (BS), methane disulfonic acid methylene ester (MMDS), ethylene sulfate (DTD), lithium difluorooxalato borate (LiDFOB) and lithium difluorobis (oxalato phosphate (LiDFOP). Preferably, in some embodiments of the present invention, the sulfur-containing additive is selected from at least one of the compounds represented by the following structural formulas: Preferably, the mass percentage of the sulfur-containing additive in the ternary high nickel lithium ion battery nonaqueous electrolyte is 0.1-0.2%. Preferably, in some embodiments of the present invention, the other film-forming additive comprises Vinylene Carbonate (VC) and further comprises at least one of lithium difluorooxalato borate (lidaob), 1, 3-Propane Sultone (PS), methylene Methane Disulfonate (MMDS), vinyl sulfate (DTD), and lithium difluorobis oxalato phosphate (LiDFOP). More preferably, in some embodiments of the present invention, the other film-forming additive comprises Vinylene Carbonate (VC) and further comprises at least one of lithium difluorooxalato borate (lidaob), vinyl sulfate (DTD), and lithium difluorobis oxalato phosphate (LiDFOP). Further, in some embodiments of the invent