Electrochemical properties of high-power lithium ion batteries made from modified spinel LiMn_2O_4  

作　　者：李向群 王志兴 梁如福 郭华军 李新海 陈启元 

机构地区：[1]School of Chemistry and Chemical Engineering,Central South University [2]School of Metallurgical Science and Engineering,Central South University

出　　处：《中国有色金属学会会刊：英文版》2009年第6期1494-1498,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project(2007CB613607)supported by the National Basic Research Program of China

摘　　要：A prismatic 204056-type high power lithium-ion battery was developed.Modified LiMn2O4 and carbonaceous mesophase sphere(CMS)were adopted as the cathode and anode,respectively.The effects of proportion of conductive carbon black in cathode and the rest time after discharge on the electrochemical properties of batteries were investigated.The electrochemical tests show that the proportion of conductive carbon black in cathodes affects the high rate capability and discharge voltage plateau distinctly.The battery with 3.0%of conductive carbon black in cathode shows excellent electrochemical performances when being charged/discharged within 2.5-4.2 V at room temperature.The discharge capacity at 20C rate is 94.4%of that at 1C rate,and the capacity retention ratio charged at 1C and discharged at 5C is 86.6%after 390 cycles at room temperature.The test result of impulse discharge at 50C for 5 s shows that the battery has outstanding high rate discharge performance when the battery is in the depth of charge of 90%,75%,60%,45%,30%and 15%.The battery also shows good charge performance.When the battery is charged at 0.5C,1C,2C and 4C,the ratios of capacity for constant current charge are 98.4%,96.4%,91.0%and 72.9%of the whole charge capacity,respectively.In addition,the rest time after discharge affects the cycle performance distinctly when the battery is discharged at high rate.A prismatic 2O4056-type high power lithium-ion battery was developed. Modified LiMn2O4 and carbonaceous mesophase sphere （CMS） were adopted as the cathode and anode, respectively. The effects of proportion of conductive carbon black in cathode and the rest time after discharge on the electrochemical properties of batteries were investigated. The electrochemical tests show that the proportion of conductive carbon black in cathodes affects the high rate capability and discharge voltage plateau distinctly. The battery with 3.0% of conductive carbon black in cathode shows excellent electrochemical performances when being charged/discharged within 2.5-4.2 V at room temperature. The discharge capacity at 20C rate is 94.4% of that at 1C rate, and the capacity retention ratio charged at 1 C and discharged at 5 C is 86.6% after 390 cycles at room temperature. The test result of impulse discharge at 50C for 5 s shows that the battery has outstanding high rate discharge performance when the battery is in the depth of charge of 90%, 75%, 60%, 45%, 30% and 15%. The battery also shows good charge performance. When the battery is charged at 0.5C, 1C, 2C and 4C, the ratios of capacity for constant current charge are 98.4%, 96.4%, 91.0% and 72.9% of the whole charge capacity, respectively. In addition, the rest time after discharge affects the cycle performance distinctly when the battery is discharged at high rate.

关 键 词：锂离子电池 电化学性能 尖晶石LIMN2O4 高功率 改性 碳质中间相 高倍率放电 放电电压平台 

分 类 号：TM912[电气工程—电力电子与电力传动] TG139.7[一般工业技术—材料科学与工程]