Template-Free Fabrication of Hollow NiO–Carbon Hybrid Nanoparticle Aggregates with Improved Lithium Storage



Hollow NiO–carbon hybrid nanoparticle aggregates are fabricated through an environmental template-free solvothermal alcoholysis route. Controlled hollow structure is achieved by adjusting the ratio of ethylene glycol to water and reaction time of solvothermal alcoholysis. Amorphous carbon can be loaded on the NiO nanoparticles uniformly in the solvothermal alcoholysis process, and the subsequent calcination results in the formation of hollow NiO–C hybrid nanoparticle aggregates. As anode materials for lithium-ion batteries, it exhibits a stable reversible capacity of 622 mAh g−1, and capacity retention keeps over 90.7% after 100 cycles at constant current density of 200 mA g−1. The NiO–C electrode also exhibits good rate capabilities. The unique hollow structures can shorten the length of Li-ion diffusion and offer a sufficient void space, which sufficiently alleviates the mechanical stress caused by volume change. The hybrid carbon in the particles renders the electrode having a good electronic conductivity. Here, the hollow NiO-C hybrid electrode exhibits excellent electrochemical performance.