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.