Self-Assembled Hybrid of Microwave-Exfoliated V2O5 Nanoribbons and Reduced Graphene Oxide Nanosheets As a Sustainable Electrode Material for Zinc Ion Batteries

Abstract

Rechargeable aqueous zinc ion batteries are an emerging topic in the battery research due to its high volumetric capacity (5855 mAh/cm3), low cost, environmental friendliness and safety. But the development of the zinc ion batteries have been seriously hindered by the slow insertion/extraction kinetics of the multivalent Zn2+ ions in the host structure. Two-dimensional (2D) transition metal oxides are intensely studied for various energy storage applications such as batteries and supercapacitors but controlled synthesis and tunable nanoscale properties are still a challenge. Herein we present and discuss the self-assembly of a hybrid material of microwave-exfoliated Vanadium pentoxide (V2O5) nanoribbons (NRs) on graphene oxide (GO) nanosheets as a potential host for zinc ion storage. Vanadium pentoxide have several advantages such as high discharge capacity (294 mAhg-1) and large abundance but suffers from low electrical conductivity and poor stability. Using a thermal treatment, the GO template is converted to reduced graphene oxide (rGO) which improves the electrical conductivity of the hybrid. Multiple divalent cations such as Zn2+ and Mn2+ have been used in the self-assembly process to bind the negatively charged V2O5 NRs and GO nanosheets to improve the stability of the hybrid and accommodate the intercalation/deintercalation of the Zn2+ ions. Incorporation of 0.0357 M Mn2+ along with 0.10 M Zn2+ in the assembly process has been found to form a stoichiometric composition of Mn0.15Zn0.08V2O5 by XPS, which provides the high specific capacity of 295 mAh g-1 at 0.5 A g-1 and a high stability with the capacity retention of ~81.3% after 500 cycles at 4 A g-1.