Non-aqueous electrolyte of lithium ion battery and lithium ion battery

Abstract

The invention discloses a non-aqueous electrolyte of a lithium ion battery and the lithium ion battery. The non-aqueous electrolyte of the lithium ion battery comprises at least one of compounds shownin the structural formula I or the structural formula II, wherein R1 and R2 in the structural formula I are independently selected from C2-C5 alkenyl and C2-C5 alkynyl, and R3 in the structural formula II is selected from C2-C5 alkenyl and C2-C5 alkynyl. According to the non-aqueous electrolyte of the lithium ion battery, the compounds shown in the structural formula I or the structural formula II are added to the electrolyte and contain unsaturated bonds and hexafluoroisopropyl, and a passivation film is formed by the unsaturated bonds on the surfaces of the positive and negative poles, inhibits the electrolyte from being decomposed on the surfaces of the positive and negative poles and prevents the positive material structure from being damaged; furthermore, by means of steric hindrancerelationship of hexafluoroisopropyl functional groups, the degree of polymerization of the unsaturated bonds can be inhibited to a certain degree; low-temperature performance of the lithium ion battery is guaranteed while high-temperature performance of the lithium ion battery is improved.

Description

technical field [0001] The present application relates to the field of lithium-ion battery electrolyte, in particular to a lithium-ion battery non-aqueous electrolyte and a lithium-ion battery. Background technique [0002] Because of its light weight, small size, high working voltage, high energy density, high output power, no memory effect and long cycle life, lithium-ion batteries are not only widely used in digital products such as mobile phones and notebook computers, It is also considered to be one of the best choices for electric vehicles and large energy storage devices. At present, electronic digital products such as smartphones and tablet computers have higher and higher energy density requirements for batteries, making it difficult for commercial lithium-ion batteries to meet the requirements. [0003] When lithium-ion batteries are charged and discharged at high temperatures or stored at high temperatures, the decomposition of the electrolyte on the surface of t...

AI Technical Summary

Problems solved by technology

However, the inventors of the present application have found through a large number of experiments that although unsaturated phosphate can significantly improve the high-temperature storage and high-temperature cycle performance of the battery, it significantly increases the internal resistance of the battery and reduces the low-temperature performance and rate performance of the battery, especially at low temperature. Cycling performance, a large area of ​​lithium precipitation occurs on the surface of the negative electrode

Chinese patent application 201180037584.4 also discloses an electrolyte solution containing triple bond unsaturated phosphoric acid ester, which mentions fluorine-substituted unsaturated phosphoric acid ester. The electrolyte of saturated phosphate ester still has poor low-temperature performance, and large-area lithium precipitation occurs during low-temperature charging, causing serious safety hazards

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