Optimising electrochemical performance of lithium-rich manganese-based ternary cathode materialxLi2MnO3·(1 ?x)LiNi0.5Co0.3Mn0.2O2by adjusting composition r

作者：Xiaoli Deng; Jin Guo; Guangxu Li; Wenzheng Zhou; Wenquan Dong; Hongliang Zhang; Xianqing Liang; Haifu Huang

来源：Micro & Nano Letters, 2018, 13(12): 1699-1702.

• electrochemical impedance spectroscopy
• crystal structure
• X-ray photoelectron spectra
• lithium compounds
• secondary cells
• electrochemical electrodes
• precipitation (physical chemistry)
• voltammetry (chemical analysis)
• X-ray diffraction
• crystal growth from solu

Herein, lithium-rich manganese-based cathode materials x Li 2 MnO 3 ·(1 ? x )LiNi 0.5 Co 0.3 Mn 0.2 O 2 with different chemical components ( x = 0. 4, 0.5, 0.6 and 0.7) were prepared by a simple co-precipitation method. The effects of different chemical components on the crystal structure and electrochemical properties of the lithium-rich manganese-based cathode materials were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, charge–discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that the sample x Li 2 MnO 3 ·(1 ? x )LiNi 0.5 Co 0.3 Mn 0.2 O 2 ( x = 0.5) shows an optimum electrochemical performance: the first discharge capacity is high up to 240.71 mAh g ?1 at 0.1 C; the discharge capacity can be maintained at 153 mAh g ?1 after cycling 50 times when measured at a high rate of 2 C, and the good cycle stability at a high charge–discharge rate, where the discharge capacity was maintained at 123.26 mAh g ?1 after 100 cycles at 5 C. Therefore, it can well balance the relationship between the specific capacity and rate capability.