“Double guarantee mechanism” of Ca2+-intercalation and rGO-integration ensures hydrated vanadium oxide with high performance for aqueous zinc-ion batteries

Ca²⁺-Intercalated hydrated V₂O₅/rGO (CaVOH/rGO) is synthesized via a facile hydrothermal process and applied as a cathode for ARZIBs with an admirable specific capacity (409 mA h g⁻¹ at 0.05 A g⁻¹) and excellent energy density (381 W h kg⁻¹).