Porous flower-like Zn0.18V2O5·0.84 H2O as cathode for ultralong lifespan aqueous zinc-ion batteries

Vanadium-based oxides have attracted extensive attention in the study of cathode materials for aqueous rechargeable zinc-ion batteries (ZIBs) due to multivalent state, high capacity and inexpensive cost. Nevertheless, the disadvantages with vanadium dissolution and poor cycle stability in the cathode limit its application. To cope with these problems, we design a novel porous zinc vanadium oxide (Zn0.18V2O5·0.84 H2O) with enhanced transport kinetics and structural stability during cycling due to the action of interlayer doping of Zn2+. Specially, the Zn0.18V2O5·0.84 H2O as the cathode of ZIBs manifests an excellent specific capacity of 416 mAh g−1 at 1 A g−1 and the retention capacity is 189 mAh g−1 after 10,000 cycles at 10 A g−1. It also offers a significant rate performance and attaches an energy density of up to 279.5 wh kg−1. Moreover, the electrode was placed in 3 M Zn(CF3SO3)2 electrolyte for 4500 h without obvious change, indicating that the porous structure is not liable to collapse, and the electrode is rich in contact with the electrolyte, which shortens the diffusion path of Zn2+.