Structure and Performance of Dual-doped LiMn sub(2)O sub(4) Cathode Materials Prepared via Microwave Synthesis Method

• Published in: Electrochimica acta Vol. 125; pp. 225 - 231
• Main Authors: Zhang, Huang, Xu, Yunlong, Liu, Dong, Zhang, Xiusheng, Zhao, Chongjun
• Format: Journal Article
• Language: English
• Published: 01.04.2014
• Subjects: Cycles; Dissolution; Electrochemical impedance spectroscopy; Electrodes; Fading; Microwaves; Shrinkage; Transmission electron microscopy
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2014.01.102

A series of LiNi sub(0.05-x)Mg sub(x)Mn sub(1.95)O sub(4) (0.01 less than or equal to x less than or equal to 0.04) compounds were synthesized using microwave irradiation as sintering technique. The structures and electrochemical performances of the as-prepared powders were characterized by XRD, SEM, EDS, TEM, electrochemical galvanostatic cycling tests, EIS and XRF. The XRD and Rietveld refinement results indicate that all samples exhibit a single spinel structure and dual-doping causes the shrinkage of lattice space. The discharge capacities and cycling performances of LiNi sub(0.03)Mg sub(0.02)Mn sub(1.95)O sub(4) are the best with a low capacity fading over the investigated 30 cycles at elevated temperature (55 degree C). These results demonstrate that the microwave sintering method and metallic ions co-doping are effective ways to suppress the Mn dissolution from active electrodes at high temperature and high rate for lithium-ion batteries.