V-MOF@carbon nanotube derived three-dimensional V2O5@carbon nanotube as high-performance cathode for aqueous zinc-ion batteries

Abstract

Aqueous zinc ion batteries (ZIBs) are considered as the next generation of power sources due to their high theoretical capacity, low redox potential, and abundant reserves. However, it has still been the main bottleneck limiting cathode materials with superior cyclic performance and rate capability for aqueous ZIBs. Here, a nanorod architecture V-MOF@CNT derived V2O5@CNT is listed as the excellent cathode composite material for ZIBs for the first time. Here, V2O5@CNT has outstanding electrochemical characteristics in aqueous ZIBs by virtue of its unique nanorod composite structure, adequate electrochemical active sites and the synergistic effect of V2O5 and carbon nanotubes. In this regard, the V2O5@CNT nanocomposite shows a high discharge specific capacity of 400 mAh g−1 at a current density of 1 A g−1, showing twice the discharge specific capacity of pure vanadium pentoxide (200 mAh g−1 at 1 A g−1). The capacity retention (84.4% after 100 cycles at 0.1 A g−1) is better than the V2O5 cathode (63.5% after 100 cycles at 0.1 A g−1). These results indicte that the V2O5@CNT cathode should provide the basis for the development of high-performance aqueous zinc ion batteries.