Na metal anodes for liquid and solid-state Na batteries

Because of the high abundance, cost-effectiveness and low redox potential of Na, rechargeable Na metal batteries (NMBs) are considered an ideal alternative and complementary to state-of-the-art lithium-ion batteries. Despite numerous research efforts that have been made to accelerate the development of the NMBs utilizing both liquid- and solid-state electrolytes, issues such as Na dendrite formation, undesirable side reactions, and infinite volume changes remain to be addressed. This review paper presents a thorough examination of the progress and accomplishments of liquid-based and solid-state NMBs. It encompasses a comprehensive analysis of fundamental studies and practical applications, an extensive comparison between Li and Na metal anodes, along with an in-depth discussion of the fundamentals of Na dendrite formation in both liquid- and solid-state electrolytes. Furthermore, we summarize various promising approaches for addressing the associated issues and challenges. Through our review, we aim to accelerate the progress in comprehending and utilizing Na metal anodes for practical NMB systems. This review provides the understanding and development of Na metal anodes for liquid-based and solid-state Na metal batteries.