Electrochemical performance of rare-earth doped LiMn _2O _4 spinel cathode materials for Li-ion rechargeable battery

摘要

Spinel powders of LiMn _(2-x)RE _xO _4 (RE = La, Ce, Nd, Sm; 0≤x≤0.1) have been synthesized by solid-phase reaction. The structure and electrochemical properties of these electrode materials were characterized by X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge-discharge experiment. The part substitution of rare-earth element RE for Mn in LiMn _2O _4 decreases the lattice parameter, resulting in the improvement of structural stability, and decreases the charge transfer resistance during the electrochemical process of LiMn _2O _4. As a result, the cycle ability, 55 °C high-temperature and high-rate performances of LiMn _(2-x)RE _xO _4 electrode materials are significantly improved with increasing RE addition, compared to the pristine LiMn _2O _4.