Chromium-containing polyanionic cathode materials for sodium-ion batteries: progress, challenges and opportunities

Abstract

Sodium-ion batteries (SIBs) have emerged as promising candidates for next-generation energy storage systems due to their abundant resources, low cost, and environmental friendliness. Among various cathode materials, chromium-containing polyanionic compounds have attracted significant attention for their high working voltage, excellent diffusion kinetics, and safety. This review provides a comprehensive overview of the recent progress in chromium-containing polyanionic cathode materials for SIBs, emphasizing the multifunctional roles of chromium in enhancing electronic conductivity, stabilizing crystal structures, and enabling high-voltage redox activity. The interplay between material composition, crystal architecture, and sodium storage behavior is discussed. Challenges such as poor high-voltage durability and interface degradation are identified, with emphasis on strategies including structural modulation, defect regulation, and interface engineering. Moreover, strategies to overcome the bottlenecks in material development, such as improving high-voltage stability, optimizing energy density, and enhancing interfacial performance, are proposed. These findings not only deepen the understanding of chromium-containing polyanionic materials but also provide a theoretical foundation for the development of efficient and safe energy storage solutions.