Hierarchical flower-like structures composed of cross-shaped vanadium dioxide nanobelts as superior performance anode for lithium and sodium ions batteries

摘要

Until now, both lithium ion batteries (LIBs) and sodium ion batteries (SIBs), have been broadly researched, which is either attractive or challenging. Among the transition metal oxides (TMOs), VO2 (B), with a high theoretical capacity and appealing rate capability, has been studied as anode materials. In our work, the flower-like structures composed of cross-shaped VO2 (B) nanobelts were synthesized via a simple solvothermal method. The electrochemical properties were investigated for lithium storage (with capacities of 529.2 mA h g(-1) at current density of 0.2 A g(-1) after 200 cycles and 683.1 mA h g(-1) at 1 A g(-1) after 1000 cycles) and sodium storage (225.2 mA h g(-1) at 0.2 A g(-1) after 200 cycles, 150 mA h g(-1) at 5 A g(-1)). The reaction mechanisms were explored by ex-situ XRD and ex-situ TEM, which reveals the intercalation mechanism for both LIBs and intercalation combined with conversion mechanisms for SIBs.