Synergistic effect of morphology evolution with oxygen vacancies on layered cathode derived from polyoxovanadates for aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have attracted increasing attention owing to the low cost, high safety and sustainability, whereas the poor electronic conductivity and durability of the cathode materials severely limits their large-scale application. Herein, the layered vanadate Fe5V15O39(OH)9·9H2O with nanobelt morphology (FeVO-B) was synthesized using polyoxovanadates as precursors, which give rise to the nanorod-like FeVO material (FeVO-R) possessing larger surface area and abundant oxygen vacancies with introducing graphene oxide as surfactant. The collaborative effect of morphological tailoring with oxygen vacancies significantly accelerates the reaction kinetics, thus facilitating the efficient zinc ion storage. As expected, the FeVO-R cathode displays a high specific capacity of 409.6 mAh g−1 at 0.1 A g−1 and significant cycle stability at 10 A g−1 (87.5% capacity retention after 3000 cycles). This work utilizes multiple strategies to achieve high performance cathodes for AZIBs.