Lithium battery electrolyte and lithium battery

Abstract

The invention relates to lithium battery electrolyte which is prepared from lithium salt, an organic solvent and additives. The additives include the additive S accounting for 0.1-10% of the total mass of the lithium battery electrolyte, the additive S is one or more of elements in the following structural formula (shown in the description), wherein R1-R5 are independently selected from H, halogen, nitryl, amino, cyano, alkyl substituted by the halogen or not substituted by the halogen, alkoxy substituted by the halogen or not substituted by the halogen, alkenyl substituted by the halogen or not substituted by the halogen, R6 represents alkyl, the halogen substituted by the halogen is F, Cl and Br, and the substitution performed by the halogen is partial or complete. The overcharge, charge and discharge performance of a lithium battery are all improved, side reaction is reduced, expansion of the battery under high temperature is decreased, and the cycle life of the battery under normal temperature, high temperature and low temperature is prolonged.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and particularly relates to a lithium battery electrolyte and a lithium battery. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, large specific energy, no pollution, no memory effect and long life, and are widely used in portable electrical devices such as mobile phones, digital cameras and notebook computers. And hybrid vehicles will also be used on a large scale. [0003] However, safety concerns are the biggest impediment to the commercialization of large lithium-ion batteries. Many burst, fire, explosion, etc. hazards are caused by overcharging of Li-ion batteries, which are caused by exothermic reactions caused by runaway battery voltage. [0004] In order to solve these problems, the traditional method is to install PTC terminals, gas expansion detection devices, explosion-proof safety valves in the safety cap of the battery, or to...

AI Technical Summary

Problems solved by technology

However, the types of current additives are basically limited to biphenyl, halobenzene (bromobenzene, chlorobenzene), and alkylbenzene. After adding such additives, it will affect the normal charge and discharge capacity of the battery and affect its cycle efficiency. It has a certain negative impact on the surface morphology of the battery material. The battery generates a large amount of gas during charging and discharging, which causes the battery to swell and degrades the performance of the lithium-ion battery.

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