A method for realizing ion doping and surface coating to modify ternary cathode material jointly by one-step method

Abstract

The invention discloses a method for realizing metal ion doping and metal oxide surface coating to modify a ternary cathode material jointly by a one-step method, which comprises the following steps:S1. mixing a complexing agent and a ternary cathode material to be dissolved in a solvent, and continuing stirring reaction after ultrasonic wave treatment; 2, adding a metal ion salt solution to be doped and coated into the mixed solution in S1 drop by drop under the stirring state, and continuing stirring e reaction; S3, heating the mixed solution in S2, continuing stirring until the solvent iscompletely volatilized to obtain a mixed powder body; S4, calcinating the powder body obtained in S3 at 400-600 DEG C for 4-6h, and cooling to room temperature to obtain the modified material. The invention adopts a simple process and a method assisted by a complexing agent to prepare a modified ternary cathode material doped with elements on the surface layer and coated on the surface layer of the material in one step. Doping effectively inhibits the crystal structure transformation of the surface layer of the material during the cycle, and the coating layer prevents the direct contact with the electrolyte, inhibits the occurrence of side reactions, and improves the cycling stability of the material. By optimizing the synthesis process, the cost can be effectively saved, and the method has great application prospects.

Description

technical field

[0001] The invention relates to the technical field of cathode materials for lithium batteries, and relates to the modification of ternary cathode materials for lithium batteries, and more specifically, to a method for jointly modifying ternary cathode materials by ion doping and surface coating in one step. Background technique

[0002] The cathode material of ternary lithium-ion battery has become a current research hotspot due to its advantages of high capacity and low cost, and is considered to be the main cathode material for the next generation of lithium-ion power battery. However, some technical barriers that still exist currently severely limit the expansion of the commercial scale of ternary materials. In particular, high-nickel ternary cathode materials still have a certain gap from large-scale commercial applications in terms of stability, safety, and rate performance.

[0003] At present, among domestic lithium-ion battery cathode materials, ter...

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