NaV6O15 microflowers as a stable cathode material for high-performance aqueous zinc-ion batteries

Reversible aqueous zinc-ion batteries (ZIBs) have great potential for large-scale energy storage owing to their low cost and safety. However, the lack of long-lifetime positive materials severely restricts the development of ZIBs. Herein, we report NaV6O15 microflowers as a cathode material for ZIBs with excellent electrochemical performance, including a high specific capacity of ∼300 mA h g−1 at 100 mA g−1 and 141 mA h g−1 maintained after 2000 cycles at 5 A g−1 with a capacity retention of ∼107%. The high diffusion coefficient and stable tunneled structure of NaV6O15 facilitate Zn2+ intercalation/extraction and long-term cycle stability.