Zn-Ion Dop Ed Regulates the Oxygen Vacancy Structure of V6o13 to Achieve High-Capacity Performance in Zinc-Ion Batteries

Abstract

Zinc-ion batteries have attracted considerable interest because of their high theoretical capacity, superior safety, and cost-effectiveness. However, the cathode materials' performance is the main factor limiting their advancement. Among various candidates, vanadium-based oxides have been widely utilized due to their outstanding properties. In this study, we successfully synthesize a Zn2+ doped V6O13 cathode material using a hydrothermal method. The introduction of Zn2+ not only altered the morphology of V6O13 but also partially replaced the vanadium atoms, leading to an increase in the oxygen vacancy content. This structural modification effectively increases the active sites for reactions, enabling the electrode material to achieve a higher specific capacity. Electrochemical analysis shows that Zn-V6O13-x exhibits a specific capacity of 442.56 mAh g-1 at a current density of 0.2 A g-1. After 1000 cycles at a current density of 5 A g-1, the specific capacity remains 211.7 mAh g-1, reflecting a capacity retention of 89.3%. The storage mechanism of Zn-V6O13-x is confirmed using various ex-situ techniques. This study enhances the use of ZIBs in the energy storage industry and offers fresh perspectives on the development of high-performance cathode materials.

Keywords: Zinc-ion battery, cathode material, V6O13, oxygen vacancy