Critical review of material design and interfacial chemistry in next-generation sodium-ion battery technology

The growing demand for renewable energy has intensified the search for efficient, scalable, and sustainable energy storage systems. While lithium-ion batteries (LIBs) have dominated this field, limitations in resource availability and cost have prompted a search for alternative energy sources. Sodium-ion batteries (SIBs) have garnered significant attention due to the natural abundance and low cost of Na. This review presents the progress in SIBs, with a focus on the development of high-performance, cost-effective, and environmentally benign materials. The historical evolution and renewed interest in SIBs are first highlighted, followed by a detailed discussion on the state-of-the-art anode and cathode materials. Anode categories include graphitic and hard carbon, alloy-type materials, and emerging materials like metal oxides, sulfides, and organics. For the cathode, layered oxides, tunnel structures, polyanionic frameworks, and Prussian blue analogs are elucidated. Furthermore, the review addresses critical developments in liquid and solid-state electrolytes, including aqueous systems, ionic liquids, and various hybrid electrolyte configurations. Challenges related to electrolyte stability, interfacial compatibility, and ion transport mechanisms are also discussed. Finally, key research directions such as fast-charging capability, low-temperature operability, and the adoption of solvent-free electrolytes have been discussed. This piece aims to guide future research toward the realization of high-capacity, cost-efficient, and environmentally sustainable sodium-ion battery technologies.