Critical roles of RuO2 nano-particles in enhancing cyclic and rate performance of LISICON Li3V2(PO4)3 cathode materials

Abstract

LISICON-type Li3V2(PO4)3 (LVP) is a promising candidate of cathode material for the next generation of lithium ion batteries. Nevertheless, the poor conductivity restricts its practical applications. Carbon coating can improve the deficiency to some extent, but the practical application of LVP is still hindered because of its inert reaction kinetics, unstable electrode structure and side-reaction. Thereby, it is still very insufficient to obtain the satisfied electrochemical performance by the simple modification of carbon coating. Herein, LVP/C@RuO2 composites are designed and characterized. The RuO2/C hybrid layer consists of RuO2 nanoparticles embedded in amorphous carbon. Benefitting from this unique design, the electronic conductivity, Li+ migration rate and structural stability can be remarkably improved. As a result, LVP/C-5 delivers a high initial capacity of 167.8 mAh g−1 at 0.2 C and superior long-term cycling performance of 81.2 mAh g−1 after 1000 cycles at 10 C. Moreover, LVP/C-5 exhibits good thermal stability (55 °C), giving a high reversible capacity of 116 mAh g−1 after 350 cycles at 5 C. More importantly, the LVP/C@RuO2 possesses a facile technical procedure, excellent electrochemical property, and shows significant potential to apply in large-scale production. Our study provides a potential reference for optimizing electrochemical properties through low dosage of carbon and low metallic oxide amount.