Progress on Fe-Based Cathode Materials for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) have received significant interest as an alternative to lithium-ion batteries (LIBs) due to the abundant availability of sodium, low cost, and enhanced safety. Among the various cathode materials explored for SIBs, iron-based cathodes stand out as promising candidates for large-scale energy storage systems due to their affordability, environmentally friendly nature, and non-toxicity. This review provides a comprehensive overview of recent advancements in Fe-based cathode materials like layered oxides, polyanionic compounds, and Prussian blue analogs. We analyze their synthesis techniques, electrochemical properties, and structural features to assess their viability for SIB applications. The impact of different synthesis methods on the electrochemical performance of these materials is highlighted and their underlying mechanisms are examined. Additionally, strategies to enhance key performance such as energy density, cycle life, and conductivity are discussed. We also address the main technical challenges that limit the practical application of iron-based cathodes, including issues with cycle stability and charge/discharge performance. In conclusion, this review presents a comprehensive overview and a forward-looking perspective on the design of Fe-based cathode materials for next-generation SIBs.