Modified high-nickel positive electrode material and preparation method thereof

Abstract

A preparation method of a modified high-nickel positive electrode material comprises the following steps: uniformly mixing a high-nickel positive electrode material precursor, an additive and a lithium source, carrying out primary sintering in an oxygen atmosphere, crushing, and sieving to obtain a primary sintered high-nickel positive electrode material; washing the primary sintered high-nickel positive electrode material with water, and drying to obtain a washed and dried primary sintered high-nickel positive electrode material; performing primary surface treatment on the washed and dried primary sintered high-nickel positive electrode material to obtain a primary surface treated high-nickel positive electrode material; and uniformly mixing the modifier with the primary surface treatmenthigh-nickel positive electrode material, and then carrying out secondary surface treatment to obtain the modified high-nickel positive electrode material. The residual alkali amount on the surface ofthe material and the specific surface area of a final product are reduced, so that the impedance on the surface of the material is obviously reduced, the gas production phenomenon of the battery is obviously relieved, the structural stability and the cycling stability of the material are improved, the processability of the positive electrode material in the preparation process can be improved, the preparation condition is easy to control, and mass production can be realized.

Description

technical field [0001] The invention relates to positive electrode materials, in particular to a modified high-nickel positive electrode material and a preparation method thereof. Background technique [0002] Due to the advantages of low raw material cost, high charge-discharge voltage, high charge-discharge specific capacity and high energy density, high-nickel cathode materials have shown great potential for development in the lithium-ion battery market, and have quickly become the research and development center in the field of lithium-ion battery cathode materials. and application hotspots. However, the high nickel content of the positive electrode material makes it more sensitive to moisture, and the surface is prone to generate relatively high alkaline substances lithium hydroxide and lithium carbonate, which reduces the stability of the surface / interface of the material, especially after washing and drying. Obviously, thereby reducing the discharge capacity and cycl...

AI Technical Summary

Problems solved by technology

However, the high nickel content of the positive electrode material makes it more sensitive to moisture, and the surface is prone to generate relatively high alkaline substances lithium hydroxide and lithium carbonate, which reduces the stability of the surface / interface of the material, especially after washing and drying. Obviously, thereby reducing the discharge capacity and cycle life of the material

Moreover, the material is easy to jelly during the processing process, which increases the difficulty of pulping and coating, and the battery produces serious gas during the test process, which further leads to the reduction of material capacity and poor cycle performance.

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