Lithium-ion battery electrolyte and lithium-ion battery

Abstract

The present application provides a lithium ion battery electrolyte and a lithium ion battery. The lithium-ion battery electrolyte includes a solvent, an electrolyte lithium salt and an additive, and the solvent includes a carbonate solvent and a carboxylate solvent; the total amount of the electrolyte is 100%, and the additive is in mass percent, including: D Dinitrile 0.1%~1%; Vinylene carbonate 0.1%~1%; Fluoroethylene carbonate 2%~10%; 1,3-propane sultone 0.1%~1%; Additive lithium salt 0.1%~ 1%. The application adopts a lithium-ion battery electrolyte composed of a specific proportion of mixed solvent, mixed additives and electrolyte lithium salt, which can significantly improve the high-temperature cycle and high-temperature storage performance of the lithium-ion battery.

Description

technical field [0001] The present application relates to the technical field of lithium-ion batteries, in particular to a lithium-ion battery electrolyte and a lithium-ion battery. Background technique [0002] Because of its high energy density, high power density, long cycle life, no memory effect, low self-discharge rate, wide operating temperature range, safety and reliability, and environmental friendliness, lithium-ion batteries have been used in portable consumer electronics, power tools, medical Electronics and other fields have been widely used, and at the same time, it has also shown good application prospects in fields such as pure electric vehicles, hybrid electric vehicles, and energy storage. [0003] In recent years, the demand for battery energy density in various fields has increased rapidly, and it is urgent to develop lithium-ion batteries with higher energy density. Therefore, the application of ternary positive electrode materials and silicon-carbon neg...

AI Technical Summary

Problems solved by technology

[0004] However, there are still two key problems that need to be solved during the use of silicon-based negative electrode materials: (1) Silicon materials repeatedly expand and shrink during the lithium-intercalation process, causing the negative electrode materials to pulverize and fall off, and eventually cause the negative electrode materials to lose electrical contact (2) The continuous growth of the solid electrolyte interfacial film (SEI) on the surface of the silicon material will irreversibly consume the limited electrolyte in the battery and lithium from the positive electrode, eventually leading to a rapid decline in battery capacity

At present, the silicon-based materials that are widely used in the market mainly relieve the volume expansion and inhibit the rebound by blending graphite, but this volume expansion problem still exists, and the problems of high-nickel positive electrode materials and silicon-carbon negative electrode materials still need to be further optimized to improve the electrolyte. battery performance

Images