The effect of surface modification on high capacity Li1.375Ni0.25Mn0.75O2+γ cathode material for lithium-ion batteries

Li1.375Ni0.25Mn0.75O2+γ exhibits an obviously enhanced electrochemical performance after AlF3 surface modification, including the high initial discharge capacities of 276.8 mA h g−1 and high coulombic efficiency of 93.6%. The results from powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP) and galvanostatical test confirm that its electrochemical improvement can be mainly attributed to the appearance of spinel-like structure on the surface of the layered material induced by AlF3-modified. Moreover, the reduced charge transfer resistance (Rct) during cycling contributes to a better cycle stability of AlF3-modified Li1.375Ni0.25Mn0.75O2+γ.