Sodiophilic design for sodium-metal batteries: progress and prospects

Sodium-metal batteries are considered as attractive energy storage systems because of the high theoretical capacity, low redox potential, and abundant resources of metallic sodium (Na). However, the uncontrolled growth of Na dendrites significantly hinders their practical feasibility, leading to poor coulombic efficiency, limited cycling lifespan, and severe safety issues. To tackle this issue, many strategies focusing on sodiophilic design have been developed to ensure uniform and dendrite-free Na deposition. Unfortunately, it is noteworthy that the latest progress in sodiophilic design lacks a comprehensive and systematic evaluation. This review begins by thoroughly elucidating the formation mechanisms of Na dendrites and the underlying causes of battery failure. Subsequently, the recent scientific advancements for extending the cycling lifespan of Na metal batteries are comprehensively summarized based on a sodiophilic design strategy. Finally, we propose conclusive insights into enhancing the sodiophilic properties of Na metal anodes, which may guide battery design and deepen the understanding of sodiophilicity for the development of Na metal batteries.