Sn-substituted LiMn_2O_4 thin films prepared by RF magnetron sputtering

摘要

The spinel thin films of LiMn_2O_4 and LiSn_(0.0125)Mn_(1.975)O_4 prepared by RF magnetron sputtering were studied with focusing on structural and electrochemical properties. The LiSn_(0.0125)Mn_(1.975)O_4 thin films showed the superior properties, i.e., a high capacity retention of 94% at the current rate of 5 C after 90 cycles, due to the increase in Mn valence and the decrease in oxygen deficiency. The larger oxygen deficiency in undoped LiMn_2O_4 thin films was confirmed by the increased lattice volume and structural degeneration.