金属氧化物掺杂改善LiFePO4电化学性能

采用氧化物前驱体对磷酸铁锂(LiFePO4)进行少量金属离子掺杂,用X射线衍射、电子扫描显微镜、循环伏安法和恒电流充放电对掺杂的LiFePO4进行了研究.结果表明,少量的掺杂离子在很大程度上提高了LiFePO4的电化学性能,特别是大电流放电性能中1.0%(摩尔分数)的Nb5 掺杂LiFePO4的1 C放电比容量约130 mAh/g.掺杂后的电化学性能与掺杂离子的半径、价态密切相关,半径合适、价态高的离子对提高LiFePO4的电化学性能有利.

Electrochemical performance of LiFePO4 by doping metal oxides

Lithium iron phosphate(LiFePO4) containing low concentration ion dopants was prepared by mixing precursors with metal oxides. The LiFePO4 samples were characterized by X-ray diffraction, scanning electron microscope, and electrochemical performance testing. The results indicate that the ion dopants do not affect the structure of the material but considerably improve its electrochemical performance, especially large current discharge behaviors. LiFePO4 samples doped with Nb5 have an initiate capacity of 130 mAh/g at 1 C. The results also verify that LiFePO4 doped with ions of suited radius and higher valence shows better electrochemical characters.