锂离子蓄电池正极材料LiMn2O4掺钒的研究

采用低温液相碳酸盐法合成了掺杂钒的Li-Mn-O正极材料.X射线衍射分析表明当掺钒量小于20%,合成的电极材料Li-V-Mn-O仍能保持LiMn2O4的尖晶石结构,当掺钒量超过20%则合成产物中不含尖晶石结构的LiMn2O4.循环伏安和恒电流充放电实验证实掺杂钒可改善Li-Mn-O正极材料电化学反应的可逆性,并提高其比容量;掺钒量大于10%时,合成产物中出现杂质相导致电极材料电化学性能下降.

Effects of the vanadium-doping on the structure and electrochemical performance of LiMn2O4

The cathode material Li Mn O with vanadium doping for lithium ion battery was prepared by low temperature liquid phase carbonate method.X ray diffraction analysis indicates that the prepared cathode material Li V Mn O still maintains the structure of spinel LiMn 2O 4 when the content of vanadium doping is less than 20%. However, when the addition amount of vanadium in the reactant is more than 20%, there is no spinel LiMn 2O 4 in the product. The results of cyclic voltammetry and constant current charge/discharge experiments show that vanadium doping improves the reversibility of the Li Mn O cathode material and increases its specific capacity. The production of impure phase in the product cause the electrochemical performance of the prepared material fade when the content of vanadium doping is more than 10%.