Battery cathode coating structure material with pinning effect and preparation method thereof

Abstract

The invention discloses a battery cathode coating structure material with a pinning effect and a preparation method thereof. A coating layer is formed on a surface of a lithium ion battery cathode material. The coating layer is metal compound of lithium. Metal cations in the coating layer form a metal cation gradient doped solid solution buffer structure on an interface of the coating layer and the cathode material. The solid solution buffer structure has a nail similar shape. A nail cap is formed in the coating layer. A nail point extends into the cathode material. The solid solution buffer structure and the coating layer are calcined in an inert atmosphere, and one-step generation is realized. According to the cathode coating structure with the pinning effect provided by the invention, through calcining in the inert atmosphere, surface oxygen defects of a high voltage cathode material LNMO are increased, the metal cations in the coating layer are enabled to diffuse and enter into thesurface detects of the cathode material in a coating process, so the pinning effect is achieved, and surface coating and surface doping integrated double modification of the high voltage cathode material of the lithium ion battery is realized.

Description

technical field [0001] The invention relates to the field of preparation and modification of positive electrode materials for new energy lithium-ion batteries, in particular to a battery positive electrode coating structure material with a pinning effect and a preparation method thereof. Background technique [0002] Lithium-ion batteries have been widely used as energy storage devices for portable electronic devices due to their high energy density, long cycle life, good thermal safety performance, and environmental friendliness, and are rapidly expanding into fields such as electric vehicles and large-scale energy storage. At present, the cathode materials of lithium-ion batteries mainly include lithium cobaltate, lithium iron phosphate, layered lithium-rich, layered high-nickel and high-voltage spinel materials. Among them, LiNi 0.5 mn 1.5 o 4 (LNMO) as a representative spinel cathode material due to its high operating voltage (~ 4.7 V), high energy density (~ 690 Wh k...

AI Technical Summary

Problems solved by technology

However, this two-step or multi-step method to achieve double modification of surface doping and surface coating has complicated procedures, poor repeatability, and is not conducive to industrial applications. At the same time, high-voltage active materials undergo two During the high-temperature calcination process, its bulk phase structure will be affected uncontrollably

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