导电氧化物AZO对尖晶石型LiMn2O4高温性能的改善及研究  

Improved Electrochemical Properties of Conducting AZO-Coated Spinel LiMn_2O_4 at 55 ℃

作　　者：夏丙波[1] 仇光超[1] 孙洪丹[1] 方国清 刘伟伟 张瑞雪[1] 王宏宇 李德成[1] 

机构地区：[1]苏州大学化学电源研究所 江苏省锂电池材料重点实验室,苏州215006 [2]常州储能材料与器件研究院,常州213003

出　　处：《无机化学学报》2014年第4期725-732,共8页Chinese Journal of Inorganic Chemistry

基　　金：科技部科研院所研究开发专项基金(No.2010EG111015)资助课题;江苏省科技支撑计划-工业项目(No.BE2013006-3)资助项目

摘　　要：采用溶胶凝胶法对尖晶石型LiMn2O4正极材料进行铝掺杂氧化锌(AZO)包覆改性,并通过XRD、SEM、EDS、TEM、EIS、ICP-AES和充放电测试等手段对其结构,形貌及电化学性能进行表征。研究结果表明,AZO包覆层有效的阻止了LiMn2O4颗粒和电解液的直接接触,抑制了高温下锰溶解,明显改善了LiMn2O4的高温循环性能。1.5wt%AZO包覆的LiMn2O4正极材料在高温(55℃)1C时,首次放电比容量为114 mAh·g-1,经过100次循环后,容量保持率仍高达95.4%,远高于未包覆LiMn2O4的70.6%。此外,1.5wt%AZO包覆的LiMn2O4表现出了优越的大倍率放电性能,在10C下放电比容量能达到99 mAh·g-1。To improve the electrochemical properties of spinel LiMn2O4 cathode material, LiMn2O4 coated with Al doped ZnO （AZO） was prepared by sol-gel method. The effects of AZO coating on the structural and electrochemical properties were investigated by XRD, SEM, EDS, TEM, EIS, ICP-AES and charge-discharge test. The results demonstrate that AZO coating can effectively obstruct the direct contact between the cathode electrode and electrolyte and suppress the dissolution of manganese into the electrolyte. It is shown that 1.5wt% AZO-coated LiMn2O4 delivers a capacity of 114 mAh ·g-1 with a capacity retention of 95.4% after 100 cycles operated at 1C rate and 55 ℃, which is obviously higher than that of bare LiMn2O4 （70.6%）. Moreover, 1.5wt% AZO-eoated LiMn2O4 presents an excellent high-rate capability with the discharge capacity of 99 mAh. g-1 at 10C rate.

关 键 词：锂离子电池 正极材料 溶胶凝胶法 LIMN2O4 锰溶解 导电AZO 包覆 

分 类 号：TM911[电气工程—电力电子与电力传动] O646[理学—物理化学]