Enhancing the electrochemical performances of LiNi0.5Mn1.5O4 by Co3O4 surface coating

A Co3O4 coating is formed on the surface of LiNi0.5Mn1.5O4 particles via an ethanol mediated precipitation method. The existence of the uniform Co3O4 coating is clearly observed by scanning electron microscopy and transmission electron microscopy. The results of electrochemical performance testing prove that the Co3O4 coating can greatly enhance the cycling stability and rate performance of LiNi0.5Mn1.5O4. The optimal sample 5% Co3O4-coated LiNi0.5Mn1.5O4 delivers a discharge capacity 126 mAh g−1 at 1 C rate with a capacity retention 96.8% after 300 cycles and a high discharge capacity 97.5 mAh g−1 at 10 C rate. The causes to the improvement are discussed based on elemental analysis, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy.