LiMn_xN_xiCo_(1-2x)O_2的自蔓延燃烧合成及电化学性能研究  

Electrochemical Performances and Synthesis of LiMn_xNi_xCo_(1-2x)O_2 by Self-Combustion Reactions

作　　者：乔亚非[1] 李新丽[1] 连芳[1] 李福燊[1] 仇卫华[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《稀有金属》2011年第4期491-497,共7页Chinese Journal of Rare Metals

基　　金：国家863资助项目(2009AA03Z226);北京市优秀博士论文专项资助项目(YB20081000801)

摘　　要：采用自蔓延燃烧法合成LiMnxNixCo1-2xO2（x=0.25,0.33,0.4,0.45）系列锂离子电池正极材料,通过X射线衍射（XRD）、X射线光电子能谱（XPS）分析研究钴含量的变化对材料结构的影响;利用场发射电子显微镜（FESEM）对材料的形貌进行了表征。由XPS图谱分析,在LiMnxNixCo1-2xO2（x=0.25,0.33,0.40,0.45）中,当x为0.4时合成材料中的Mn3＋和Ni3＋相对含量较少。在2.5~4.5 V电压范围和0.5C充放电条件下,LiMnxNixCo1-2xO2（x=0.25,0.33,0.40,0.45）的初始放电比容量分别为174,177,180和155 mAh.g-1,循环40次后的容量保持率分别为87.7%,88.0%,90.9%和87.7%,LiMn0.4Ni0.4Co0.2O2的初始放电比容量最高且循环性能最好。在LiMnxNixCo1-2xO2（x=0.25,0.33,0.40,0.45）中,随着钴含量的增加,其倍率性能越好。LiMnxNixCo1-2xO2（x=0.25,0.33,0.4,0.45） cathode materials were synthesized by self-combustion reactions（SCR）.The X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS） were used to analyze the structure change when the content of cobalt increased.The morphology of LiMnxNixCo1-2xO2（x=0.25,0.33,0.4,0.45） was revealed by FESEM.In LiMnxNixCo1-2xO2（x=0.25,0.33,0.40,0.45）,it had the least content of Mn3＋and Ni3＋,when x was 0.4.When charged and discharged at 0.5C in the voltage range of 2.5~4.5 V,the initial discharge capacities of LiMnxNixCo1-2xO2（x=0.25,0.33,0.40,0.45） were 174,177,180 and 155 mAh·g-1 respectively,and the capacity retention after 40 cycles were 87.7%,88%,90.9% and 87.7%.LiMn0.4Ni0.4Co0.2O2 exhibited the highest specific discharge capacity and the best cycling performance in all samples.In LiMnxNixCo1-2xO2（x=0.25,0.33,0.4,0.45）,with the Co content increasing,the rate capability was improved.

关 键 词：锂离子电池 自蔓延燃烧法 倍率性能 LiMnxNixCo1-2xO2 

分 类 号：TM912.9[电气工程—电力电子与电力传动]