Recent advanced skeletons in sodium metal anodes

The sodium metal anode exhibits great potential in next-generation high-energy-density batteries due to its high theoretical capacity (1165 mA h g−1) at low redox potential (−2.71 V versus standard hydrogen electrode) as well as the high natural abundance and low cost of Na resources. However, its practical application in rechargeable batteries is hindered by uncontrollable dendrite growth that leads to poor coulombic efficiency, short lifespan, infinite volume change and even safety issues during plating/stripping processes. Among various strategies, the application of skeletons for Na metal anodes demonstrates a positive influence on reducing local current density, inhibiting dendrite growth, and alleviating volume expansion. This work reviews the research progress of various skeleton materials for sodium metal anodes in recent years, including carbon-based skeletons, alloy-based skeletons, metallic skeletons and MXene-based skeletons. Simultaneously, the recent technological advances and strategies are summarized and categorized. Finally, we discuss the development prospects and research strategies of skeleton materials in sodium metal anodes from the perspective of basic research and practical applications.