High nickel content Li(NixCoyMn1-x-y)O2 (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).

Abstract
1. Introduction
2. Experimental Procedure
3. Results and Discussion
4. Conclusion
Acknowledgement
References
Author Information

• Dong Myung Kim(Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Republic of Korea)
• Chunjoong Kim(Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Republic of Korea) Corresponding author
• Ju Yeong Lee(Gumi Electronic and Information Technology Research Institute, Gumi 39171, Republic of Korea)
• Gyu-Seok Choi(Gumi Electronic and Information Technology Research Institute, Gumi 39171, Republic of Korea) Corresponding author