Kinetic study of LiMn_2O_4 in process of lithium intercalation

摘要

Exchange current density of spinel LiMn_2O_4 was studied by linear polarization. The relationship of the kinetic property with the structure of spinel LiMn_2O_4 was investigated by studying the effect of the doping and surface coating on the kinetic properties of electrode material. The results show that the exchange current density of spinel LiMn_2O_4 electrode increases with the increase of the amount for lithium intercalation at first, and then decreases. The maximal exchange current density appeares at the 80%-90% lithium intercalation. The similar phenomenon was observed on the doped spinel LiMn_2O_4 electrode. Doping can enhance the exchange current density of spinel LiMn_2O_4 material. However, the degree of the doping effect varies with the doped element varying. Surface coating can also enhance the exchange current density of spinel material, and the increment of value is higher than that of doped ones.