Spinel lithium titanate (Li4Ti5O12, LTO) is applied as an epitaxial coating layer on LiMn2O4 hollow microspheres (LMO) through solvothermal-assisted processing. The epitaxial interface between LTO and LMO can be clearly observed by high resolution transmission electron microscopy (HR-TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with atomic resolution images. The epitaxial coating cathode (EC-LMO@LTO) exhibits an excellent cyclability, thermal and rate capability for LIBs cathode due to the complete, thin LTO coating layer with strong adhesion to the host material. In addition, the small structure mismatch and high Li(+)-ion mobility of LTO can be beneficial to forming an efficient tunnel for Li(+)-ion transfer at the interface. It is suggested that EC-LMO@LTO can be recognized as a promising cathode material in electric vehicles (EVs) and plug-in hybrid electric vehicles (HEVs).
Keywords: Li-ion batteries; heteroepitaxial structure; lithium titanate coating; solvothermal; spinel lithium manganese oxide.