Solvothermal synthesis of sea urchin-like NaxV2O5 structure for ultra-high stability aqueous zinc ion batteries

Abstract

Vanadium pentoxide, as a low-cost, safe and reliable cathode electrode material. Its structure is prone to collapse during the process of repeated Zn2+ intercalation and deintercalation of aqueous zinc-ion batteries (AZIBs), so enhancing the structural stability of vanadium pentoxide and improving the rate performance has always been a challenge. In this work, sea urchin-like NaxV2O5 vanadate materials are obtained by solvothermal reaction, and the prepared samples exhibit a fast ion transport path during the process of Na+ chemical embedding in V2O5 framework, which is due to the plentiful active sites that nanowires can provide. This paves the way for high magnification performance. In addition, the unique sea urchin-like morphology with a large specific surface can continuously adapt to strain during ion insertion to obtain excellent long cycle performance. The above merits endow NaVO with a highly stable discharge capacity of 250.5 mA g−1 at 0.5 A/g and a long cycle capacity of 100 mA h g−1 maintains for more than 11,000 cycles at 10 A/g. Remarkably, the capacity retention rate up to 85.7%.