Synthesis and electrochemical performance of LiCr_xMn_(2-x)O_4 (x=0,0.02,0.05,0.08,0.10)powders by ultrasonic coprecipitation

摘要

LiCr_xMn_(2-x)O_4(x=0,0.02,0.05,0.08,0.10)compounds with a spinel crystal structure have been prepared by a novel ultrasonic co-precipitation method.The effects of the calcination temperature and the citric acid-to-metal ion molar ratio (R)on powder characteristics and electrochemical performance are evaluated.It is found that the optimum R and sintering temperature for LiCr_xMn_(2-x)O_4 materials by the ultrasonic co-precipitation method are R =5/6 and 800 deg C,respectively.The calcined powders are loosely bound agglomerates of abnormally coarsened particles with a narrow range of particle sizes.The effect of Cr doping was also explored.Electrochemical studies show that optimum materials synthesized by the ultrasonic co-precipitation method demonstrate good cycling performance.