Effect of Ammonia Concentration during Coprecipitation Reaction on the Multi-Component Hydroxide Precursors and Cathode Materials

High nickel content Li(Ni x Co y Mn 1-x-y )O 2 (NCM, x 0.9) cathode materials suffer from rapid capacity fading, a significant obstacle to their commercial application.To mitigate this issue, strategies such as doping and coating with various elements have been widely reported.In particular, multi-element doping has been explored as a potentially more effective alternative to single or dual element modification.Concurrently, the synthesis of high-entropy precursors via coprecipitation has gained significant attention.In this study, high nickel content precursors with nine components were synthesized by hydroxide coprecipitation under varying concentrations of ammonia that was employed as a chelating agent.The primary particle morphology of the precursors was found to be dependent on the ammonia concentration, which in turn influenced the physicochemical and electrochemical properties of the final cathode materials.At low ammonia concentration, the formation of secondary phases was detected.Notably, the cathode synthesized under high ammonia concentration exhibited excellent cycling stability, delivering a discharge capacity of 164.22 mAh/g after 100 cycles at 1 C, which corresponds to a capacity retention of approximately 91 % of its initial discharge capacity (180.50 mAh/g at 0.1 C).