Enhanced high temperature performance of LiMn 2 O 4 coated with Li 3 BO 3 solid electrolyte

Cathode material, LiMn2O4, was synthesized by solid-state reaction followed by surface coating of Li3BO3 solid electrolyte. Structure and electrochemical performance of the prepared powders were characterized by X-ray diffraction, scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge techniques, respectively. Results show that Li3BO3 coated LiMn2O4 has similar X-ray diffraction patterns as LiMn2O4. The discharge specific capacities of LiMn2O4 coated with 0·1, 0·3 and 0·6 wt% Li3BO3 are 123·3, 118·2 and 110 mAh/g, respectively, which is slightly smaller than that of 124·4 mAh/g for LiMn2O4. However, the capacity retention of Li3BO3 coated LiMn2O4 is at least 5·6 and 7·6% higher than LiMn2O4 when cycled at room temperature and 55 °C, respectively. Li3BO3 coated LiMn2O4 shows much better cycling behaviours than LiMn2O4.