Highly enhanced lithium storage capability of LiNi0.5Mn1.5O4 by coating with Li2TiO3 for Li-ion batteries

A uniform and thin Li2TiO3 layer with various amounts was coated on the surface of nanostructured LiNi0.5Mn1.5O4 (LNMO) materials by in situ hydrolysis of tetrabutyl titanate (TBOT) followed by the lithiation process. The morphology and structure of the samples were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM) with an energy-dispersive X-ray spectroscope (EDS). Electrochemical tests illustrate that Li2TiO3 as a Li+-conductive coating layer remarkably improved the rate and cycling performance of the LNMO spinel cathode. Particularly, the 3 wt% and 5 wt% Li2TiO3-surface modified samples deliver high discharge capacities of 95 mA h g(-1) and 90 mA h g(-1) even at a high current density of 5 C, while the bare one only has a discharge capacity of 70 mA h g(-1). At a current density of 1 C at elevated temperature, the 3 wt% and 5 wt% Li2TiO3-surface modified LNMO samples show excellent cyclability. After 50 cycles, the capacity retention of 3 wt% and 5 wt% Li2TiO3 modified LNMO is 88.1% and 94.1%, while only 77.1% for the bare sample.