Lithium-conductive LiNbO3 coated high-voltage LiNi0.5Co0.2Mn0.3O2 cathode with enhanced rate and cyclability

• Published in: Green energy & environment 2022-04, Vol.7 (2), p.266-274
• Main Authors: Yu, Haifeng, Wang, Shouliang, Hu, Yanjie, He, Guanjie, Bao, Le Quoc, Parkin, Ivan P., Jiang, Hao
• Format: Article
• Language: English
• Subjects: Confined synthesis; Cycling stability; Li-ion batteries; NCM523; Surface coating
• ISSN: 2468-0257; 2468-0257
• DOI: 10.1016/j.gee.2020.09.011

LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode materials can operate at extremely high voltages and have exceptional energy density. However, their use is limited by inherent structure instability during charge/discharge and exceptionally oxidizing Ni4+ at the surface. Herein, we have developed a citrate-assisted deposition concept to achieve a uniform lithium-conductive LiNbO3 coating layer on the NCM523 surface that avoids self-nucleation of Nb-contained compounds in solution reaction. The electrode–electrolyte interface is therefore stabilized by physically blocking the detrimental parasitic reactions and Ni4+ dissolution whilst still maintaining high Li+ conductivity. Consequently, the modified NCM523 exhibits an encouraging Li-storage specific capacity of 207.4 mAh g−1 at 0.2 C and 128.9 mAh g−1 at 10 C over the range 3.0–4.5 V. Additionally, a 92% capacity retention was obtained after 100 cycles at 1 C, much higher than that of the pristine NCM523 (73%). This surface engineering strategy can be extended to modify other Ni-rich cathode materials with durable electrochemical performances. We develop a citrate-assisted deposition concept to achieve a uniform lithium-conductive LiNbO3 coating layer on the NCM523 surface. Therefore, the capacity retention at 10C have been improved from 45% to 63% relative to 0.2C. [Display omitted]