Preparation and Properties of Positive Electrode Material WO3·0.33H2O for Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (ZIBs) have attracted considerable attention due to their outstanding safety and cost-effectiveness; however, further exploration of cathode materials remains necessary. This study investigates the preparation of WO₃·0.33H₂O with various nanostructures through the hydrothermal method using different raw materials. WO₃·0.33H₂O synthesized with the structure-guiding agent dodecyl benzene sulfonic acid (DBSA) exhibits a snowflake spherical structure, facilitating the insertion and extraction of Zn²⁺. The initial specific discharge capacity reaches 76.455 mA h g^–1 at a current density of 50 mA g^–1, surpassing that of WO₃·0.33H₂O (57.715 mA h g^–1) prepared with nitric acid, despite both samples sharing identical crystal shapes. Following cycling at high current densities, both samples recover their initial levels of current density and exhibit similar capacity decay (only 2 mA h g^–1). Consequently, nanostructured WO₃·0.33H₂O demonstrates exceptional electrochemical performance, suggesting its potential application in aqueous zinc-ion batteries.