Highly Enhanced Electrochemical Performance of LiNi0.5Co0.2Mn0.3O2 by Surface Coating with Li-Ti-O Nanoparticles for Lithium-Ion Batteries

The Li-Ti-O-coated LiNi0.5Co0.2Mn0.3O2 (LTO@NCM) cathode materials are synthesized via an in situ co-precipitation method followed by the lithiation process and thermal annealing. The Li-Ti-O coating layer is designed to strongly adhere to the core-material with diffusion pathways for Li+ ions. Measurements and analysis of structure, morphology and electrochemical properties have been applied. X-ray diffraction patterns showed the existence and conversion of lithium titanium oxide (Li-Ti-O labeled as LTO). Electrochemical tests suggest that compared with pristine NCM, The LTO layer works both as an excellent Li ion conductive layer and as a protective coating layer against the attack of HF in the electrolyte, and remarkably improves the cycling performance at higher charged state and rate capability of the LTO@NCM composite material. 3.0 wt.% LTO-coated NCM (LTO3) material exhibited higher capacity retentions of 94.8% than that of the bare one (58.2%) and nickel-riched cathodes (90-91%) after 100 cycles at cut-off charge voltages of 4.3V at 1C rate.