Research Progress and Prospect of Perovskite and Anti‐Perovskite Solid Electrolytes for Sodium Solid‐State Batteries

Sodium solid-state batteries (SSSBs) are poised to revolutionize energy storage by capitalizing on sodium's exceptional crustal abundance (2.36% vs 0.0017% for lithium) and cost-effectiveness, addressing critical sustainability challenges of lithium-dependent technologies. Solid electrolytes (SEs) with high ionic conductivity and stability have gained significant attention. The compositional and structural flexibility of perovskites and anti-perovskites make them competitive, and the combination of advanced computer simulations and synthesis techniques can achieve stable synthesis of the materials. Importantly, the high ionic conductivity and high stability of perovskite and anti-perovskite SEs at room temperature endow them with enormous potential for the construction of SSSBs. In this review, the research progress of perovskite and anti-perovskite SEs for SSSBs is summarized, different optimization strategies for improving the ionic conductivity of SEs are compared, and an in-depth discussion on the chemical and electrochemical stability of SEs is provided. Specifically, key technical indicators reflecting their structural tolerance and future application potential have been summarized and discussed for the first time. Among these, anti-perovskites, due to their diversity and the presence of more ion transport channels, have the potential to become commercial SEs. Finally, the future challenges and development directions of perovskite and anti-perovskite SEs for SSSBs have been prospected.