V-MOF derived porous V2O5 nanoplates for high performance aqueous zinc ion battery

Rechargeable aqueous zinc-ion battery is a promising energy storage device because of its low cost and high safety. However, they are still in their infancy due to the limited choice of cathodes with high capacity and satisfactory cycling performance. In this work, porous V₂O₅ materials were obtained by pyrolysis of vanadium-MOF and adopted as intercalation cathode for aqueous zinc-ion batteries. V₂O₅ purchased commercially as a control, the effects of specific surface area, pore size distribution and mixed valence of electrodes on the performance of batteries were studied. The novel cathode delivers high capacities of 300 mA h g⁻¹ compared to 60 mAh g⁻¹ for C-V₂O₅ at current density of 100 mA g⁻¹. The energy density of this Zn ion battery is about 230 Wh kg⁻¹, which is much higher than commercial lead acid batteries. The capacity of P-V₂O₅ electrode retains 120 mA h g⁻¹ even at 2000 mA g⁻¹, which is much higher than that of C-V₂O₅. Moreover, the structure of V₂O₅ nanoplates and their composites with carbon materials can improve the cyclic stability.