Enhanced electrochemical performance of LiNi0.8Co0.1Mn0.1O2 by surface modification with lithium-active MoO3

LiNi0.8Co0.1Mn0.1O2 cathode materials coated with MoO3 were synthesized via drying coating process with low velocity ball milling. The crystal structure and particle morphology of the sample were examined and observed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed that the surface modification had a little change on the samples and illustrated that the components of the coating layer were MoO3/Li2MoO4. Electrochemical results demonstrated that the MoO3 coated samples exhibited preeminent electrochemical performance compared with the bare samples. Particularly for the 3 wt% MoO3 coated samples, its initial coulombic efficiencies increased from 83.3% to 89.0%. Furthermore, the 3 wt% MoO3 coated samples exhibited the highest capacity retention of 94.8% after 100 cycles at 1 C, and possessed the excellent rate discharge performance at a high current density. The electrochemical impedance spectroscopy and cyclic voltammetric results suggested that the layered MoO3 coating could suppress the augmenter of the charge transfer resistance and stabilize the active material structure during cyclic process.