Lithium ion battery positive pole material, preparation method thereof, lithium ion battery positive pole and all-solid-state lithium battery

Abstract

The invention relates to a lithium ion battery positive pole material, a preparation method thereof, a lithium ion battery positive pole and an all-solid-state lithium battery. The positive pole material comprises a core-shell structure composite material; the core-shell structure composite material comprises a core material, an inner shell material and an outer shell material; the core material comprises a positive pole active substance; the inner shell material is a positive pole active substance containing fluorine; and the outer shell material contains oxyfluoride. According to the lithiumion battery positive pole material disclosed by the invention, a fluorinated layer is adopted as an inner shell, the oxyfluoride is adopted as an outer shell; and since the formed core-shell structure is coated with the two shells, a coating structure is stable, and therefore, interface reaction or element diffusion between the positive pole material and a solid electrolyte can be avoided, and atthe same time, element diffusion between the positive pole material and the coating is reduced, and therefore, the interface of the positive pole material can be greatly optimized. With the method for preparing the positive pole material disclosed by the invention adopted, coating and fluorination can be completed in one step; coating temperature is low; operation is simple and feasible; elementinterpenetration is reduced; and the interface of the positive pole material is optimized.

Description

technical field

[0001] The present disclosure relates to the field of all-solid-state lithium batteries, in particular, to a lithium-ion battery cathode material and a preparation method thereof, a lithium-ion battery cathode and an all-solid-state lithium battery. Background technique

[0002] The interface between the positive electrode material and the solid electrolyte of an all-solid-state lithium battery is prone to element diffusion, resulting in a decrease in battery performance. Most of the existing technologies are to coat the positive electrode material, so as to improve the interface between the positive electrode and the solid electrolyte. The commonly used coating materials are Li 4 Ti 5 o 12 、Al 2 o 3 , LiNbO 3 Wait. However, the performance improvement brought by a single coating to the cathode material is limited, and it cannot solve the problem of interfacial diffusion between the cathode material and the coating. Contents of the invention

[0003] ...

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