CoO-loaded graphitable carbon hollow spheres as anode materials for lithium-ion battery

A new type of CoO nanoparticles encapsulated by graphitable hollow carbon sphere (GHCS) composite material was synthesized. The core–shell structure CoO/GHCS composite shows the improved cyclability as an anodic material in Li-ion battery. The core–shell composite containing 50 wt% CoO exhibits a reversible capacity of 584 mAh g⁻¹ at a constant current density of 100 mA g⁻¹ between 0 and 3.0 V (vs. Li⁺/Li), and remains a capacity retention of 95% after 50th cycle. The improvement could be attributed to that the GHCS with a good electronic conductivity and high surface severs as dispersing medium to prevent CoO nanoparticles from aggregating, and provide the enough space to buffer the volume change during the Li-ion insertion and extraction reactions in CoO nanoparticles.