MOF-derived heterostructured C@VO2 @V2O5 for stable aqueous zinc-ion batteries cathode

Abstract

Rationally designed cathode materials with high specific capacity and excellent cycling stability are indispensable for stable and highly efficient aqueous zinc-ion batteries (AZIBs). The mesoporous nanocomposite C@VO2 @V2O5 is successfully synthesized using the vanadium-based metal-organic framework as precursor by carbonization and subsequent oxidation processes. As the AZIBs cathode, the MOF-derived heterostructured materials display a high specific capacity (376 mAh g−1 at 0.05 A g−1), excellent rate capability (178 mAh g−1 at 5 A g−1) and outstanding long-life cycling (90.3% capacity retention for 2000 cycles at 5 A g−1). The promising electrochemical performance is attributed to abundant Zn2+ active sites and rapid intercalation kinetics of Zn2+ originated from the heterojunction structure at the two-phase (VO2 @V2O5) interface and mesoporous structure, and the enhanced electron transport efficiency brought by the the porous carbon skeleton with high conductivity. Furthermore, the synergistic effect of dual-ion co-intercalated energy storage mechanism endows C@VO2 @V2O5 with impressive electrochemical performance. This work demonstrates MOF-derived hetero-structured materials as an alternative cathode for high cyclic stability AZIBs in the future.