掺钛、钴、镍的Li-Mn-O尖晶石的电化学性能研究  

Electrochemical performance of the Ti- and Ni-Ti- and Co-Ti-doped Li-Mn-O spinels

作　　者：童庆松[1] 杨勇[1] 

机构地区：[1]福建师范大学化学与材料学院

出　　处：《电源技术》2006年第1期28-33,共6页Chinese Journal of Power Sources

基　　金：教育部重点项目(03065;JA02159);国家自然科学基金资助课题(29925310)

摘　　要：由掺钛电解二氧化锰与氢氧化锂及掺杂剂烧结制备掺钛或掺镍-钛或掺钴-钛的尖晶石锂锰氧化物样品。在4.6～2.5V电压范围和1C倍率的电流下充放电时,600℃掺钛样、600℃和750℃的未掺杂样的初始容量分别为205mAh/g、189mAh/g和207mAh/g;将经过40循环测试并以充电态存放3个月的600℃掺钛样、600℃和750℃未掺杂样再次充放电时,初始放电容量分别为175mAh/g、135mAh/g和126mAh/g,在40循环中平均1次循环的容量衰减率分别为0.4%、1.1%和1.3%。循环伏安实验表明,掺钛明显改善充放电反应的可逆性。拉曼分析表明,掺钛对充电态样品的Mn-O键有明显的增强作用。XRD(X射线衍射)分析表明,600℃掺钛样具有立方晶格,晶轴a为0.8242nm。因此,掺钛可以明显改善样品的放电性能和充电态存放性能。A series of Ti-, Ti-Ni-, and Ti-Co-doped spinels were synthesized by sintering the mixture Ti-doped electrolytic manganese dioxides, LiOH·H2O and dopant. In the voltage region of 4.6 to 2.5 V and 1C current, the charge-discharge experiment shows that Ti-doped spinels sintered at 600℃, spinels without doping sintered at 600 ℃ and 750 ℃, exhibit a initial capacity of 205, 189 and 207 mAh/g, spectively. And also exhibit a initial capacity of 175, 135 and 126 mAh/g aider cycled and stored for 3 months at charged state and the average capacity attenuation ratio in each cycle of 40-cycle was 0.4 %,1.1%, 1.3 %, respectively. Cyclic voltammetry experiment shows the titanium dopant obviously improves the reversibility of charge-discharge reaction. Raman analyses show that the Ti dopant enhances Mn-O bond at charged state over the samples without cycling or without doping. XRD data exposure that the Ti doped spinel sintered at 600℃ possesses a cubic structure and its a axis is 0.824 2 nm. Therefore,Ti dopant can improve the reversibility of charge-discharge reaction and storage performance.

关 键 词：掺杂锂锰氧化物 托曼光谱 充放电循环 贮存性能 

分 类 号：TM912.9[电气工程—电力电子与电力传动]