Synthesis of cobalt-doped V2O3 with a hierarchical yolk–shell structure for high-performance lithium-ion batteries

Abstract

Transition metal oxides as electrode materials for LIBs are constrained by tremendous volume changes, self-aggregation and poor conductivity. Therefore, it is extremely imperative and necessary to develop a new electrode material with high capacity and long-term cycles. In this paper, yolk–shell Co-V₂O₃-24 nanospheres assembled with nanosheets were designed and synthesized through a one-step solvothermal treatment and calcination process. The results show that the anion plays a significant role in morphology induction during the solvothermal reactions. As an anode material, Co-V₂O₃-24 displayed an outstanding reversible specific capacity of 986.2 mA h g⁻¹ at 0.5 A g⁻¹ after 630 cycles with a high capacity retention rate. Even when tested at 5 A g⁻¹ after 2200 cycles, the specific capacity of 457.6 mA h g⁻¹ can be retained, which indicates that Co-V₂O₃-24 has excellent rate performance and cycle stability. The outstanding lithium storage properties mainly benefit from the novel 3D hierarchical structure, Co doping and abundant electrochemical active sites.