Nanoparticle MoO2 composited with biomass-derived carbon micron balls used as enhanced bifunctional cathode materials

Abstract

Transition metal oxides (MOx) with high theoretical specific capacity are considered as potential anode materials for batteries. However, it is mainly limited by poor electrical conductivity, slow reaction kinetics during discharge/charge and large volume variation. In this study, we designed and synthesized a feasible strategy to fabricate core-shell structures by coating MoO2 nanoparticles on the surface of biomass carbon spheres to prepare C@MoO2 composite materials (SSCCM) and demonstrate their excellent electrochemical properties as anode materials for lithium/sodium ion batteries (LIBs/SIBs). The nanostructure of MoO2 and the core-shell structure formed by SSCCM can reduce the capacity attenuation caused by volume expansion in the charging and discharging process, thus improving the cycle stability. In addition, biomass carbon and MoO2 have been shown to be strongly linked by C-O-Mo bond, which provides a good pathway for charge transfer and thus improves the rate performance. Due to the above characteristics, the capacity of SSCCM as the anode of LIBs finally stabilizes at 1441.3/654.9 mAh·g−1 after 100/1000 cycles at 0.2/2 C current density. When it is used as a SIBs anode material, the capacity stabilizes at 345.6 mAh·g−1 after 180 cycles at 0.2 C current density. Excellent cycling performance, high capacity and good rate performance make this material have broad prospects in LIBs/SIBs field.