锂离子正极材料LiCo_(1-x)Mg_xMnO_4与LiCo_(1-x)Al_xMnO_4(x=0,0.02,0.05,0.1)的制备及其电化学性能  

Synthesis and Electrochemical Properties of LiCo_(1-x)Mg_xMnO_4 and LiCo_(1-x)Al_xMnO_4(x = 0, 0.02, 0.05, 0.1) as Positive Materials for Lithium-Ion Batteries

作　　者：游美玲[1] 童庆松[1] 李秀华[1] 林忞 黄行康[1] 杨勇[2] 

机构地区：[1]福建师范大学化学系,福建福州350007 [2]厦门大学固体表面物理化学国家重点实验室,化学化工学院化学系,福建厦门361005

出　　处：《电化学》2014年第1期22-27,共6页Journal of Electrochemistry

基　　金：福建省教育厅科技项目(A类;No.JA10072);福建省高校杰出青年科研人才计划项目(No.JA11040);福建省自然科学基金计划项目(No.2011J05021)资助

摘　　要：采用固相法合成掺杂镁和铝尖晶石LiCoMnO4材料,研究镁和铝掺杂量对尖晶石LiCoMnO4电极的初始容量、放电平台以及循环性能的影响.利用扫描电子显微镜、粉末X-射线衍射仪观察分析材料形貌及结构.结果表明,所合成材料的粒径分布均匀,结晶性较佳.LiCoMnO4电极初始容量为87.0 mAh·g-1,少量镁或铝掺杂使电极初始容量有所增加,LiCo0.98Mg0.02MnO4和LiCo0.98Al0.02MnO4电极初始容量分别为91.3和93.6 mAh·g-1,提高了其5 V放电平台的比例,过量掺杂则其容量降低.此外,掺杂Al显著改善了LiCoMnO4电极的循环性能,而掺杂镁对电极的循环性能其影响不明显.The Al-doped and Mg-doped LiCoMnO4 materials were synthesized through solid-state reaction. The effects of doping amounts of Mg and A1 on the initial capacities, discharge plateaus, and cycle performances were investigated. The morphologies and structures of the as-prepared materials were studied by scanning electron microscopy and powder X-ray diffraction. The results indicate that the as-prepared samples were composed of uniform, well-crystallized particles. The pristine LiCoMnO4 possessed an initial capacity of 87.0 mAh. g-l, while LiCo0.98Mg0.02MnO4 and LiCo0.98Alo0.02MnO4 delivered their initial values of 91.3 and 93.6 mAh. g^-1, respectively. The proper doping amotmt increased the capacity and the ratio of discharge plateau at 5 V while over-doping decreased the discharge capacity of LiCoMnO4. In addition, A1 doping significantly improved the cycle performance of LiCoMnO4, while no apparent influence with Mg doping.

关 键 词：固相合成 尖晶石LiCoMnO4 镁掺杂 铝掺杂 锂离子电池 正极材料 

分 类 号：TM912[电气工程—电力电子与电力传动]