Core–shell Co3O4/ZnCo2O4 coconut-like hollow spheres with extremely high performance as anode materials for lithium-ion batteries

Abstract

Core–shell Co₃O₄/ZnCo₂O₄ coconut-like hollow spheres are synthesized by a facile two-step method. As the anode of lithium-ion batteries, their reversible capacity is up to 1278 mA h g⁻¹ at 0.1C rate and remains at 1093 mA h g⁻¹ after 50 cycles, much higher than that of pure Co₃O₄. Even after 300 cycles (cycling for more than 4 months), their reversible capacity can maintain at 934 mA h g⁻¹ at 0.2C rate. Such superior electrochemical performance (high reversible capacity, excellent long-term cycling stability and good rate capability) can be ascribed to the unique core–shell hollow structure, complex synergistic effect, good electrical conductivity and interfacial charging mechanism. The present results demonstrate that the core–shell Co₃O₄/ZnCo₂O₄ hollow spheres are promising anode materials for high-performance lithium-ion batteries.