Doped and coated single crystal cathode material and method for doping and coated single crystal cathode material

Abstract

The invention discloses a doped and coated single crystal positive electrode material and a method for doping and coated single crystal positive electrode material. Wherein, the single crystal positive electrode material is prepared by the following steps: mixing a lithium source, a precursor, a dopant and a coating agent to obtain a raw material mixture; sintering the raw material mixture to obtain a high-temperature reaction product; and grinding the high-temperature reaction product after cooling After sieve treatment, a doped-coated single-crystal cathode material is obtained. The present invention stabilizes the layered material structure and suppresses O 2‑ to O 2 The oxidation process of the layered phase prevents the transformation of the spinel structure; at the same time, the fast ion conductor formed by the coating agent and the residual lithium reduces the surface alkali content, reduces the specific surface area of ​​the material, improves the thermal stability of the material, and then improves the structural stability and electrical conductivity. Chemical properties: The preparation method of the present invention adopts the traditional sintering method for bulk phase doping, and is simple to operate and easy to industrialized production.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a doped and coated single crystal positive electrode material and a method for doping and coated single crystal positive electrode material. Background technique [0002] Lithium batteries are widely used in various fields such as electronic products, automobiles, and aerospace due to their high energy density and good cycle performance. As people have higher and higher requirements on the environmental protection, battery life, and life of lithium-ion batteries, the design and optimization of batteries are becoming more and more important. As the core of lithium-ion batteries, the quality of the cathode material directly determines the performance of the battery. Multi-element cathode materials have become an important cathode active material for current lithium-ion batteries, such as NCM523, NCM622, NCM811, etc., which have been commercialized on a large scale. With...

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Problems solved by technology

The technical solution coating in these two patents involves solvent method and secondary calcination, the process is complicated and the cost is high

[0004] However, these technical solutions in the prior art still have certain technical problems, for example, the wet coating process is more, the cost is higher, the use of organic chemical reagents is not conducive to environmental protection, the particle shape of the ring-breaking powder, the particle The specific surface area increases, and the post-processing is relatively complicated; metal oxides are used as additives, and metal elements will diffuse into the particles and increase the metallicity of the particle surface, and the coated metal oxides are all non-electrochemically active materials, which have poor ion conductivity; The positive electrode material is doped and coated with two-step or even three-step calcination, the process is complicated, it is not conducive to industrial production, and the production cost is high

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