烧结时间对LiNixMn2-xO4表面修饰LiCoO2性能的影响  

Effect of sintering time on the performance of LiNi_xMn_(2-x)O-coated LiCoO_2

作　　者：姚晓林[1] 张承平[2] 陈春华[2] 

机构地区：[1]安徽农业大学理学院,安徽合肥230036 [2]中国科学技术大学化学与材料学院,安徽合肥230026

出　　处：《合肥工业大学学报（自然科学版）》2008年第5期724-727,共4页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(50372064)

摘　　要：用LiNixMn2-xO4修饰锂离子电池正极材料LiCoO2,在850℃分别进行2 h4、h7、h和10 h的烧结处理,对所得产物进行了X射线衍射测试,并进行充放电容量测试和平台效率的评价,在包覆量不同的情况下研究了反应时间对LiCoO2循环稳定性和平台效率的影响。对包覆后LiCoO2样品,在电化学性能测试中,3.5%包覆量烧结时间为7 h的样品表现出最好的电化学性能,其初始容量为139.3 mAh/g,120次循环后容量139.5 mAh/g,保持率为100%;而在包覆量为10%时,放电比容量和平台效率相对较低。The LiNixMn2-xO4 film was mated on the surface of LiCoO2 cathode material and sintered at 850 ℃ for 2 h, 4 h, 7 h and 10 h respectively. The effects of sintering time on the electrochemical behavior of LiCoO2were discusse＆ The structures of the coated LiCoO2 were characterized by XRD and the electrochemical performance was tested after assembling these samples into Li-ion batteries. It could be seen from the results that sintering time affects the electrochemical performance of LiCoO2 to a certain extent. The surface modified LiCoO2 cathode material had increased actual specific capacity and stabilized cycling performance. The electrochemical measurements showed that the product obtained from sintering for 7 h has the best cycling behavior. The initial capacity of 3. 5% LiNixMn2-xO4 coated LiCoO2 was 139. 3 mA · h/g. The capacity amount of Li- NixMn2-xO4 coated LiCoO2 after 120 cycles was 139. 5 mA · h/g. The LiNixMnz-xO4 coated LiCoO2 has the excellent cycling performance and the capacity retention attains to almost 100% after 120 cycles. Moreover, it is found that the discharge capacity gradually increases with the increment of the cycle number, especially in the initial 10 cycles, The discharge capacity and plateau efficiency of 10% LiNixMn2-xO4 coated LiCoO2 were lower

关 键 词：LICOO2 表面修饰 平台效率 烧结时间 

分 类 号：TM912[电气工程—电力电子与电力传动]