Vanadium-Based Cathodes Modification via Defect Engineering: Strategies to Support the Leap from Lab to Commercialization of Aqueous Zinc-Ion Batteries

In advancing aqueous zinc-ion batteries (AZIBs) toward commercial viability, vanadium (V)-based cathodes are pivotal, offering broad redox ranges, and compatibility with water's electrochemical limits. Despite their great potentials, V-based cathodes face challenges in transitioning from lab to commercialization. Defect engineering is exploited as a pivotal technique that endows the cathodes with unexpected physical and chemical properties to break the intrinsic bottleneck and, in turn, enhance their electrochemical performances. This review delves into the role of defect engineering on V-based materials, underscoring its potential in mitigating the critical challenges. It starts by encapsulating the current characteristics of V-based cathodes in AZIBs. Research efforts related to various defects, such as oxygen vacancies, cation vacancies, cationic doping, anionic doping, water intercalation, and lattice disorders/amorphization, are then rationalized and discussed. The fabrication and characterization techniques of defect engineering are also summarized. By integrating the conclusions from existing works and tailoring defect engineering strategies, a few perspectives are provided for systematically employing defect engineering to pave the way for a more efficient transition of these promising materials from laboratory breakthroughs to commercially viable energy storage solutions.