Synthesis and electrochemical performance of Ni and F doped LiMn2O4 cathode materials

• Main Authors: Wang, Qingqing, Zhang, Xiusheng, Xu, Yunlong, Liu, Dong, Dong, Hui, Zhang, Yang
• Format: Journal Article
• Language: English
• Published: 07.09.2015
• ISSN: 2046-2069
• DOI: 10.1039/c5ra14231h

A series of Ni and F ion doped LiMn 2 O 4 composite cathode materials are synthesized via a sol-gel method with citric acid as the chelating agent. The morphology and structure of LiNi x Mn 2− x O 4− y F y were characterized by XRD, SEM, EDS and the electrochemical performance was tested and characterized by CV and EIS. The results showed that Ni and F ions were uniformly dispersed in the lattice without changing the structure and morphology of LiMn 2 O 4 . LiNi 0.03 Mn 1.97 O 3.95 F 0.05 exhibits an excellent electrochemical performance among all the samples, and delivers an initial discharge capacity of 120.3 mA h g −1 at 1C and with a retention of 94.5% (25 °C) and 80.4% (55 °C) after the 100th cycle respectively. The results demonstrated that the dual-doping of Ni and F ions in lithium manganate can prevent the manganate from dissolving in the electrolyte and enhance the cycling performance at elevated temperatures, exhibiting excellent performance at different discharge rates. A series of Ni and F ion doped LiMn 2 O 4 composite cathode materials are synthesized via a sol-gel method. LiNi 0.03 Mn 1.97 O 3.95 F 0.05 exhibits an excellent electrochemical performance.