A Novel Raw of Alkaline Stripped Pentavalent Vanadium Solution for High-Capacity Sodium Vanadate Aqueous Zinc Ion Battery Cathode

High capacity and good stability of sodium vanadate for aqueous zinc ion batteries are urgently desired. The alkaline stripped pentavalent vanadium solution was used to prepare Na0.58V2O5·0.11H2O with high interlayer spacing. As cathode for aqueous zinc ion battery, the Na0.58V2O5·0.11H2O delivers a high initial discharge capacity of 542 mAh g−1 at 0.2 A g−1 and a high capacity of 437 mAh g−1 at 1 A g−1 after 100 cycles corresponding to high retention of 91.2%. The ex-situ X-ray diffraction result shows the generation of an open-structured zinc pervanadate (Zn3(VO4)2·2.93H2O) during the discharge/charge process, which promotes the excellent cyclic performance of the Na0.58V2O5·0.11H2O. The low-cost material with high performance is a promising candidate for cathode in aqueous zinc ion batteries.