Synthesis of polycrystalline K0.25V2O5 nanoparticles as cathode for aqueous zinc-ion battery

Abstract Polycrystalline K 0.25 V 2 O 5 nanoparticles have been synthesized and evaluated as cathode for aqueous zinc-ion batteries, which demonstrates excellent Zn 2+ storage capability. As elucidated, a high capacity of 306 mA h g −1 , excellent rate capability of 5 A g −1 and long-term cyclic stability up to 500 cycles at 2 A g −1 are achieved. The effect of the K + ions and the role of morphology for K 0.25 V 2 O 5 cathode were also discussed in this work. CV measurements at different rates demonstrate that partial surface-controlled capacitive behavior contributes to the capacity of polycrystalline K 0.25 V 2 O 5 nanoparticles. The zinc storage mechanism is investigated, which demonstrates as a highly reversible intercalation-type cathode for K 0.25 V 2 O 5 with unique three-dimensional tunnel structure.