Carbon Coated Vanadium Dioxide Composites for Aqueous Zinc Batteries Based on Facile In-Situ Carbon-Impregnation Engineering

Abstract

Abstracts Vanadium oxide cathodes hold significant promise for aqueous zinc-ion batteries (AZIBs) under their excellent reversibility and capacity. However, their application is hindered by challenges such as vanadium ion dissolution and poor electrical conductivity. To overcome these issues, the development of advanced vanadium oxide cathode materials is of pivotal importance for the progression of AZIB technology. In this study, a carbon-coated vanadium dioxide (VO2@C) composite was fabricated through a hydrothermal process that involves mixing a vanadium precursor with glucose. This straightforward in-situ carbon-impregnation technique is designed to improve cathode performance by effectively preventing vanadium ion dissolution and enhancing both electronic conductivity and structural stability. Therefore, the VO2@C composite demonstrates exceptional electrochemical performance. It achieved an impressive capacity of 350 mA h g−1 at a current density of 0.2 A g−1. Even at 5 A g−1, the capacity reached 257 mA h g−1, reflecting outstanding rate capability. Furthermore, the Zn||VO2@C battery showed remarkable long-term cycling stability, maintaining a substantial capacity (234 mA h g−1) after 2000 cycles at 5 A g−1. This outstanding zinc-ion storage capability is largely attributed to the in-situ carbon-impregnation process, which effectively prevents vanadium ion dissolution and enhances the conductivity of the amorphous carbon.

Keywords: aqueous zinc ion batteries, vanadium dioxide, carbon-impregnation, In situ synthesis