Effects on surface modification of spinel LiMn2O4 material for lithium-ion batteries

Surface modification effects of the spinel LiMn2O4 cathode by a LiCoO2 precursor solution have been studied in terms of electrochemical performance and impedance response. The LiCoO2-modified LiMn2O4 cathode shows superior capacity retention of 91% than does the as-received LiMn2O4 (74% of capacity retention) after the 1st storage at 55 °C. AC impedance spectra of the LiCoO2-modified sample, in case of the after storage, show significantly improved impedance behaviors when compared with that of the as-received sample. Hence, the LiCoO2-modified LiMn2O4 cathode helps in improving the electrochemical cycling stability, especially in periodic storage at elevated temperature.