NASICON‐Type Na 3 Zr 2 Si 2 PO 12 Solid‐State Electrolytes for Sodium Batteries**

Abstract Owing to their low cost, high energy density, and reliable safety, all‐solid‐state sodium batteries have been regarded as one of the most promising candidates beyond lithium‐ion batteries. Sodium super ionic conductor (NASICON)‐structured solid‐state electrolytes (SSEs), with good electrochemical stability and environmental friendliness, are potential candidates for SSEs. In this Minireview, we summarize the basic properties of Na 3 Zr 2 Si 2 PO 12 SSEs, including structural characteristics, preparation methods, ionic conductivity, and the strategies, substituting proper elements, optimizing preparation approaches, increasing packing density, and so forth, to improve the bulk and grain boundary conductivity. Additionally, we also analyze the challenges and approaches for interfacial modification between electrodes and SSEs in all‐solid‐state sodium batteries. Finally, future research directions for facilitating the development of all‐solid‐state sodium batteries are proposed.