Al离子掺杂正极材料LiMn_2O_4的高温循环性能  

Cycling Performance of LiMn_2O_4 Cathode Materials Doped with Al^(3+) at Elevated Temperature

作　　者：李智敏[1] 罗发[1] 张玲[1] 朱冬梅[1] 周万城[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室

出　　处：《稀有金属材料与工程》2007年第A02期623-626,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(90305016)

摘　　要：采用固相反应法分别合成正极材料LiMn_2O_4和LiAl_xMn_(2-x)O_4(x=0.05,0.1,0.3)。对它们进行XRD和SEM测试,并对比了高温下的循环性能。结果显示:除Al掺杂量x=0.3时,合成物出现了LiAlO_2杂质相外,其余皆具有单一的尖晶石相结构。掺杂后的晶体颗粒比较圆润。LiMn_2O_4在高温下经过20次循环后,其比容量降低29%,衰减很快。造成衰减的主要原因是Mn^(3+)歧化反应生成的Mn^(2+)在电解液中的溶解,以及Jahn-Teller效应。通过阳离子Al^(3+)的掺杂,有效的提高了尖晶石LiMn_2O_4的高温循环性能。Cathode materials of LiMn2O4 and LiAlxMn2-xO4 （x=0.05, 0.1, 0.3 ） were synthesized by solid-state reaction, respectively, and investigated by XRD and SEM. Their cycling performances were compared at elevated temperature. The results show that the powders synthesized have the structure of spinel phase, except for nominal LiA10.3Mn1.7O4 with the impurity LiAlO2. The morphology of particle doped with Al3. is smoother than that of undoped. The specific capacity of LiMn204 decreases heavily after 20 cycles at elevated temperature, with a capacity loss of 29%, mainly due to the effect of Jahn-Teller and disproportionating reaction of Mn3~, which can generate Mn^2＋ to be dissolved into electrolyte. But through Al^3＋ doping, cycling performance of LiMn2O4 is improved obviously at elevated temperature.

关 键 词：正极材料 锰酸锂 LiA1xMn2-xO4 高温循环性能 

分 类 号：TM912[电气工程—电力电子与电力传动]