关键词: 电化学, 制备, 高镍材料, 正极, 锂离子电池, 工艺

Abstract:

The high nickel cathode materials are considered as key materials for upgrading energy density of current lithium-ion battery due to their high theoretical specific capacity (270mA·h/g). Currently, the ternary hydroxide precursors of high nickel materials are typically prepared using co-precipitation methods, which is significant in determining the performance of the final sintered material. During the co-precipitation process, factors such as ammonia content, pH value, reaction temperature, solid content, stirring rate and impurities jointly affect the physicochemical properties of the product, making it challenging to synthesize cathode materials with targeted performance. This work investigated the preparation process and basic properties of high nickel precursors with different particle size distributions and nickel contents of 88%, 90%, 92%, and 94% (molar ratios of Ni in Ni, Co, Mn). Furthermore, focusing on the precursor material with a nickel content of 94%, the effects of synthesis parameters, ammonia content, pH and stirring rate, on the properties of the precursor product were explored. It was found that under relatively low ammonia content, pH and stirring speed conditions, it was easier to prepare precursors with uniform particle size distribution and intact morphology. Moreover, the resulting high nickel materials exhibited higher discharge capacity and initial coulombic efficiency.

Key words: electrochemistry, preparation, high nickel material, cathode, lithium-ion battery, technology