Recent progress in the synthetic protocols for vanadium oxide-based cathodes in rechargeable aqueous zinc-Ion batteries

With the increasing demand for high-energy-density batteries with enhanced stability, aqueous zinc-ion batteries (AZIB) have emerged as a promising solution due to their high theoretical capacity, low redox potential, cost-effectiveness, and the inherent safety provided by aqueous electrolytes in combination with Zn metal anodes. Extensive research has focused on developing high-capacity and durable cathodes, with materials such as vanadium oxides (e.g., V2O₅, V2O3, and other VxOy forms, including Na- and K-doped variants) being explored. Vanadium oxides stand out due to their variable valence states and the ability to exist in different hydrate forms depending on the presence of water, as well as their diverse morphologies, which can be tailored by varying the synthesis methods. These properties allow vanadium oxides to achieve higher capacity, superior rate capability, and lower cost compared to manganese oxides and Prussian Blue analogs. The versatile crystalline structures of vanadium oxides enable rapid ion diffusion and electron transport, contributing to improved rate performance. Additionally, vanadium oxides exhibit enhanced electrochemical stability and reduced solubility in electrolytes, ensuring prolonged cycle life compared to manganese oxides, which are prone to dissolution. This review aims to provide an in-depth examination of various high-performance synthesis methods for vanadium oxide-based cathodes, including doped forms, and their associated electrochemical properties, highlighting significant advancements in the field that enhance the performance and stability of AZIB, thereby underscoring their strong potential for future energy storage applications.