Modified metallic current collectors for sodium metal anodes

Abundant and inexpensive sodium metal anode with low redox potential and high theoretical capacity shows great potential in next-generation high-energy–density energy storage batteries. However, the uncontrollable growth of sodium dendrites during cycling decays cell cycle life, limiting the practical application and large-scale production of sodium metal batteries. To resolve this problem, researchers have proposed many strategies to inhibit the growth of sodium dendrites. Among those strategies, metal current collectors structuring stands out for its unique role in mitigating volume fluctuations caused by sodium metal plating/stripping, reducing energy barrier for sodium nucleation, and providing a large number of nucleation sites. Therefore, this review presents the basic requirements for metallic current collectors of sodium metal anodes and summarizes research progress of three common categories of metallic current collectors. Finally, the challenges and future directions of further modifying metallic current collectors are proposed.