掺杂LiM_xV_(3-x)O_8正极材料的电化学性能

Electrochemical Properties of Cathode Materials LiM_x V_(3-x) O_8

以柠檬酸为螯合剂,应用溶胶-凝胶法制备锂离子电池正极材料LiV3O8,并通过掺杂过渡金属离子M(Mn、Ti、Co和Ni)部分取代V,经烧结制得LiMxV3-xO8.X射线衍射、热重/差热、扫描电镜及充放电和循环伏安等表征样品的结构、形貌和检测电极电化学性能.结果表明,烧结温度对样品的结构、形貌和性能均有影响.500℃烧结6 h的LiV3O8,在1.8～3.8 V范围内,首次放电比容量达到300.4 mAh.g-1.掺杂x=0.1的Ti、Co可改善LiMxV3-xO8电极材料的循环性能和寿命.

The cathode material of LiMxV3-xO8 was fabricated by sol-gel method using citric acid as a chelating agent and doping transition metal ions M（Mn,Ti,Co and Ni）.The structure,morphology and electrochemical proprieties of LiMxV3-xO8 were investigated by XRD,TGA/DTA,SEM,charge-discharge and CV measurements.The results showed that different calcining temperatures result in different structures and morphologies,which lead to different discharge capacities.The specific discharge capacity of the sample calcined at 500 ℃ for 6 h was up to 300.4 mAh/g in the first cycle,and the capacity decreased with the increasing of calcining temperature.The performance and life cycle of Ti-,Co-doped LiMxV3-xO8 electrodes were significantly improved.