中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 31 No. 4 April 2021 |
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, Central South University, Changsha 410083, China;
3. Engineering Research Center of the Ministry of Education for Advanced Battery Materials, Central South University, Changsha 410083, China;
4. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China;
5. College of Chemistry, Tianjin Normal University, Tianjin 300387, China）
Abstract:Single-crystal Ni-rich cathode material LiNi0.88Co0.09Al0.03O2 (SC) was synthesized by a high-temperature solid-state calcination method. Physicochemical properties of primary and delithiated SC samples were investigated by X-ray diffractometry, X-ray photoelectron spectroscopy, and transmission electron microscopy. Electrochemical performance was characterized by long-term cycling, cyclic voltammetry, and in-situ impedance spectroscopy. The results indicated that high temperature rendered layered oxides to lose lithium/oxygen in the interior and exterior, and induced cationic disordering. Besides, the solid-phase synthesis process promoted phase transformation for electrode materials, causing the coexisting multi-phase in a single particle. High temperature can foster the growth of single particles, but it caused unstable structure of layered phase.
Key words: lithium-ion battery; cathode material; single-crystal; electrochemical performance; phase transformation
