Abstract:
In order to improve the electrochemical performance of LiNi
0.5Co
0.2Mn
0.3O
2 (NCM), WO
3 coated NCM (NCM@WO
3) composite cathode materials were synthesized with a liquid phase evaporation process. The structure and morphology of the NCM@WO
3 composite were characterized by XRD, SEM and TEM. The electrochemical performance of the NCM@WO
3 composite was characterized by charge-discharge test, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the NCM@WO
3 composite with 3wt% WO
3 has the best performance, it delivers an initial discharge capacity of 179.9 mA·hg
-1 with a low irreversible capacity loss of 42.4 mA·hg
-1 at 0.5 C, and the capacity retention after 50 cycles is 98.3%. The improved electrochemical properties of the NCM@WO
3 composite are mainly attributed to the WO
3 coating, which improves the lithium ions diffusion rate and suppresses the interface reaction between the cathode and the electrolyte.