To Study the Effect of Al2O3 Nano-powder Coating As an Electrode Material in Lithium Batteries

LiMn₂O₄ precursors were prepared by chemical precipitation and the precursors were coated to prepare LiMn₂O₄ composites. X-ray diffraction and scanning electron microscopy showed that LiMn₂O₄ had been successfully combined with Al₂O₃. Electrode charge-discharge and electrochemical impedance tests showed that the cycle performance of LiMn₂O₄/Al₂O₃ at high rate is the best. The initial discharge capacity of LiMn₂O₄/Al₂O₃ reached 104.4 mA h g^–1. After 100 cycles, the capacity retention rates of 1, 2, and 5 C were 78.9, 75.1, and 69.7%, respectively, compared with only 70.8, 62.6, and 52.8% for pristine LiMn₂O₄. The improved electrochemical performance was attributed to the nanoscale oxides hindering the reaction between the electrolyte and the electrode, which effectively improved the stability of the material during high current charging and discharging.