MoO2-loaded porous carbon hollow spheres as anode materials for lithium-ion batteries

Abstract

In this study, novel MoO2-loaded porous carbon hollow sphere composite materials were synthesized. The composites consisted of homogeneous hollow microspheres with a size of ∼0.7 ± 0.1 μm and a shell thickness of ∼70 nm; MoO2 nanoparticles with an average size of ∼12 nm were uniformly dispersed in the shells of the porous carbon hollow spheres (PCHS). The MoO2/PCHS composites showed high capacity and excellent capacity retention when they were applied as an anode material for Li ion batteries. The composite containing 44.2% of MoO2 revealed a reversible capacity of 574 mAh g−1 at a current density of 50 mA g−1, and a first coulombic efficiency of 61%. After 80 cycles, this composite still retained a capacity of 640 mAh g−1. The good electrochemical performance could be due to the fact that the MoO2 nanoparticles were homogeneously embedded in the shells of the porous carbon hollow spheres in the composites, which effectively prevented volume change or aggregation of the MoO2 nanoparticles during the lithium ion insertion/extraction process. The porous carbon hollow spheres with good electronic conductivity and high surface area offered a large electrode/electrolyte contact area, and a short path length for the Li+ transport.