Effect of TiO2-coating on structure and electrochemical performance of LiCo0.2Ni0.4Mn0.4O2

Abstract

LiCo 0.2 Ni 0.4 Mn 0.4 O 2 , as the cathode material for lithium ion batteries, was modified by TiO 2 -coating. The effect of TiO 2 -coating on the structure and electrochemical performance of LiCo 0.2 Ni 0.4 Mn 0.4 O 2 was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and galvanostatic charge-discharge tests. The results suggest that a small amount of TiO 2 -coating does not change the crystalline structure, but considerably improves the electrochemical performance of LiCo 0.2 Ni 0.4 Mn 0.4 O 2 in terms of capacity delivery and cyclability. XPS measurements confirm that the improved electrochemical performance is most possibly attributed to a decrease in interaction between the layered material and non-aqueous electrolyte during the charge-discharge processes.