Engineering ion transport in all-solid-state sodium-ion batteries: fundamentals, strategies, and perspectives

Rechargeable sodium-ion batteries (SIBs) offer a promising solution for large-scale energy storage systems due to their abundant availability and cost-effectiveness. Recently, all-solid-state sodiumion batteries (ASSSIBs) with solid electrolytes have garnered significant attention for their superior energy density and safety compared to traditional SIBs with organic liquid electrolytes (OLEs). Despite notable progress, the sluggish ion transport remains a substantial barrier to the practical application of ASSSIBs. This review comprehensively examines the ion transport mechanisms and challenges in solid electrolytes, electrode/solid electrolyte interfaces, and electrodes of ASSSIBs. Additionally, it systematically explores representative strategies to enhance ion transport through engineering solid electrolytes, interfaces, and electrodes. Furthermore, it addresses the remaining challenges and future directions for advancing highperformance practical ASSSIBs. By providing development history, fundamental insights, effective strategies, and perspectives on designing ASSSIBs for rapid ion transport, this review could serve as a comprehensive guide for scientific research and practical development in the field.