Composite solid electrolyte, all-solid-state lithium ion battery and preparation method of all-solid-state lithium ion battery

Abstract

The invention discloses a composite solid-state electrolyte, an all-solid-state lithium ion battery and a preparation method thereof. The composite solid-state electrolyte is composed of three layersof solid-state electrolytes with different components, and the composite solid-state electrolyte comprises an electrolyte coated on the negative electrode side, an electrolyte coated on the positive electrode side and a composite solid-state electrolyte located between the positive electrode electrolyte and the negative electrode electrolyte. In addition, an all-solid-state lithium ion battery isprepared through the solid electrolyte. Electrolyte which is not prone to electrochemical reduction and good in electrode interface compatibility is adopted to coat one side of the negative electrode,and electrolyte resistant to high voltage is selected to coat one side of the positive electrode, so the interface compatibility of the electrolyte and an electrode material is effectively improved,and the interface impedance is reduced; the solid electrolyte between the positive electrolyte and the negative electrolyte has relatively high ionic conductivity, so the ionic conductivity of the whole composite solid electrolyte is improved; meanwhile, the prepared all-solid-state lithium ion battery has excellent cycling stability and high safety.

Description

technical field [0001] The invention belongs to the technical field of solid-state lithium-ion batteries, and in particular relates to a composite solid-state electrolyte, an all-solid-state lithium-ion battery and a preparation method thereof. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, high specific energy, long cycle life, low self-discharge rate, and no pollution. They are widely used in 3C products, new energy electric vehicles, and electric bicycles. However, the organic carbonate-based liquid electrolyte commonly used in lithium-ion batteries currently used has risks such as leakage, combustion, and explosion. For these problems, the urgent demand for batteries with high safety, high specific capacity, and long life in the future has promoted the research and development of all-solid-state lithium batteries. Using solid electrolytes instead of liquid electrolytes is one of the effective ways to improve the safety o...

AI Technical Summary

Problems solved by technology

Although the solid electrolytes currently prepared can solve the safety problem of lithium-ion batteries well, due to the poor compatibility with the electrode material interface, the interface resistance is large, and the cycle performance is low.

In addition, the current research on solid-state lithium-ion batteries has a low voltage, and in today's era of lithium batteries that pursue high energy density, increasing the voltage of lithium batteries is one of the effective ways to increase energy density