Tailoring defects and interfaces in sulfide solid electrolytes for high-performance solid-state sodium batteries

This review focuses on defect chemistry and ion transport in sodium sulfide solid electrolytes, emphasizing the influence of intrinsic and extrinsic defects, grain boundaries, and insights from advanced computational studies. By comparing sodium and lithium electrolyte systems, it highlights the unique challenges and opportunities in sodium-based solid electrolytes. Additionally, doping strategies, emerging materials, and hybrid approaches to enhance ionic conductivity and interfacial stability are explored. Practical implications regarding defect formation energies, grain boundary contributions, and interface effects are critically discussed, providing a comprehensive roadmap for advancing solid-state sodium batteries.