Enhanced electrochemical properties of lithium-reactive V2O5 coated on the LiNi_(0.8)Co_(0.1)Mn_(0.1)O2 cathode material for lithium ion batteries at 60 °C

摘要

The cycling performance of a lithium-reactive V2O5 coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O2 material at 60 °C is substantially improved by a wet-coating process. The V2Os-coated materials are obtained from drying a mixture consisting of NH4VO3 and LiNi_(0.8)Co_(0.1)Mn_(0.1)O2 powders dispersed in ethanol at 85 °C followed by firing at 300 °C for 5 h. The morphology of the V2O5-coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O2 particle synthesized by this coating process is characterized by SEM, TEM and EDX analysis. The V2O5 layer is homogeneously coated onto the particle and the coating thickness was found to be approximately 10-30 nm. The capacity improvement at 60 °C is related to the fact that the highly distributed V2O5 near the surface diminishes the side reactions between the cathode and electrolyte. Moreover, the improvements may also benefit from the unique structure and properties of V2O5.