Towards extreme fast charging of 4.6V LiCoO2 via mitigating high-voltage kinetic hindrance

• Published in: Journal of energy chemistry Vol. 78
• Main Authors: Tang, Yu, Zhao, Jun, Zhu, He, Ren, Jincan, Wang, Wei, Fang, Yongjin, Huang, Zhiyong, Yin, Zijia, Huang, Yalan, Zhang, Binghao, Yang, Tingting, Li, Tianyi, Gallington, Leighanne C., Lan, Si, Ren, Yang, Liu, Qi
• Format: Journal Article
• Language: English
• Published: United States Elsevier 01.12.2022
• Subjects: fast charging; high-voltage LiCoO2; Li-ion battery; Li-ion diffusion; structural evolution
• ISSN: 2095-4956

High-voltage LiCoO2 (LCO) is an attractive cathode for ultra-high energy density lithium-ion batteries (LIBs) in the 3C markets. However, the sluggish lithium-ion diffusion at high voltage significantly hampers its rate capability. Herein, combining experiments with density functional theory (DFT) calculations, we demonstrate that the kinetic limitations can be mitigated by a facial Mg2++Gd3+ co-doping method. The as-prepared LCO shows significantly enhanced Li-ion diffusion mobility at high voltage, making more homogenous Li-ion de/intercalation at a high-rate charge/discharge process. The homogeneity enables the structural stability of LCO at a high-rate current density, inhibiting stress accumulation and irreversible phase transition. When used in combination with a Li metal anode, the doped LCO shows an extreme fast charging (XFC) capability, with a superior high capacity of 193.1 mAhg-1 even at the current density of 20C and high-rate capacity retention of 91.3% after 100 cycles at 5C. In conclusion, this work provides a new insight to prepare XFC high-voltage LCO cathode materials.