VO2·xH2O nanorods used as cathode materials for aqueous zinc-ion batteries
Aqueous zinc-ion batteries(AZIBs)with excellent electrochemical properties,environmen-tal friendliness,and low cost have emerged as promising energy storage devices.However,slow transport kinetics and unstable host structure are significant obstacles to develop advanced cathode materials for high-performance AZIBs.The reaction between tetraformylphenylboronic acid and vanadium pentoxide was used to prepare hydrated vanadium oxide(VO2·xH2O)nanorods containing oxygen defects through a simple one-step hydrothermal reaction.The morphology and structure of VO2·xH2O were characterized by XRD,Raman,FTIR,SEM and XPS.VO2·xH2O nanorods as cathode materials for AZIBs exhibited excellent zinc storage performance,mainly due to the efficient transport kinetics and abundant reaction sites of the material.It can provide a high discharge specific capacity of 314/199 mAh·g-1 at a current density of 0.5/5.0 A·g-1.Therefore,a simple strategy to synthesize high-performance AZIBs cathode materials was provided,and it would provide scientific guidance for the design of other advanced cathodes.