Ultrafast synthesis of vanadium-based oxides with crystalline-amorphous heterostructure for advanced aqueous zinc-ion batteries

The development of amorphous-crystalline hybrids shows significant promise for high-performance cathodes in aqueous zinc ion batteries (ZIBs). However, efficient and controlled synthesis remains a major challenge due to the thermodynamic instability of amorphous materials. In this study, we present a facile and ultrafast method for the controlled fabrication of crystalline V2O3 and amorphous sodium vanadate (V2O3 /a-NVO) heterostructure using the flash Joule heating technique, achieved in approximately 3 s. Benefitting from abundant storage sites and isotropic charge transfer channel of a-NVO, as well as the intimate contact between V2O3 and a-NVO, the resulting heterostructure exhibits significant pseudocapacitive contribution and accelerated reaction kinetics, further facilitated by the co-insertion of H+/Zn2+. This results in impressive electrochemical performance, with a high specific capacity of 414.6 mAh/g at 0.2 A/g and a capacity of 329.2 mAh/g at a current density of 1 A/g after 1000 cycles. Notably, it retains a high capacity of 138 mAh/g after 5000 cycles at a large current density of 10 A/g. This approach offers a facile and rapid strategy for designing efficient vanadium-based oxide cathodes through the rational design of amorphous-crystalline heterostructures.