Lithium ion battery and electrolyte thereof

Abstract

The invention discloses a lithium ion battery and electrolyte thereof, the lithium ion battery electrolyte comprises a non-aqueous organic solvent, lithium salt and additives, wherein the additives include an additive A-ring phosphonitrile compound, an additive B lithium fluoride phosphate compound and additives C, and the additives C are selected from at least one of a silane phosphate ester compound, a silane phosphite ester compound and a silane borate compound. Compared with the prior art, a nickelic positive pole lithium ion battery using the lithium ion battery electrolyte has ideal circulation capacity retention ratio, storage capacity retention ratio and lower gas output under high temperature, has lower direct current internal resistance under low temperature and can improve the heat stability of the lithium ion battery remarkably.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and more specifically, the invention relates to a lithium ion battery and an electrolyte thereof. Background technique [0002] Due to the characteristics of high energy density, long cycle life, and no pollution, lithium-ion batteries have broad application prospects in consumer electronics, power vehicle batteries, and energy storage power supplies. [0003] With the development of the lithium-ion battery industry, people have put forward higher requirements for the battery life of lithium-ion batteries. In order to improve the energy density of lithium-ion batteries, it is one of the effective ways to develop cathode materials for lithium-ion batteries with high specific capacity. At present, high-nickel cathode materials have become a research hotspot due to their higher theoretical specific capacity than other cathode materials. However, the use of high-nickel cathode materials in batt...

AI Technical Summary

Problems solved by technology

However, the use of high-nickel cathode materials in batteries still faces many problems, which are mainly reflected in: 1) The nickel content in high-nickel cathode materials is very high, which makes it highly oxidizable, causing the electrolyte to easily generate electricity on the surface of the cathode. The chemical oxidation reaction causes the structure change of the high-nickel cathode material at the same time, leading to the reduction reaction and dissolution of transition metal ions such as nickel and cobalt; Some additives in the electrolyte have chemical side reactions; 3) The thermal stability of high-nickel cathode materials is poor

All of the above problems will deteriorate the electrochemical performance and safety performance of lithium-ion batteries containing high-nickel cathode materials

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