Inorganic Na⁺ conducting solid-state electrolyte (SSE) has received extensive attention in assembling large-scale sodium metal batteries. However, continuous Na dendrites propagation has prevailingly hampered its implementation due to premature cell failure and safety concerns. Herein, a coating layer of AlF₃ was decorated between Na anode and NASICON SSE for the first time, which can in situ form a Na⁺ conducting buffer layer by a conversion reaction with Na during initial cycles. Profiting from the intimate modification of AlF₃ interlayer, the Na/SSE interfacial contact is extremely ameliorated. Moreover, owing to the “overpotential triggering” mechanism of the reaction between AlF₃ and Na, the locally agminated electron at the anode-electrolyte interface can be released by preferentially driving more Na⁺ to react with AlF₃ instead of forming dendrites at large current density. According to DFT calculations, the critical dendrites length is also enlarged owing to the increased interfacial energy between AlF₃-induced interlayer and Na. Therefore, the critical current density of Na/AlF₃-NASICON/Na cells has multiplied three-fold to 1.2 ​mA ​cm⁻² at 60 ​°C, and the cycling stability of Na metal SSE batteries is also dramatically ameliorated. The rational strategy of modifying AlF₃ interlayer is believed to be helpful in resisting dendrites propagation among solid alkalis metal batteries.

无机Na ⁺导电固态电解质（SSE）在组装大型钠金属电池方面受到广泛关注。但是，由于细胞过早失效和安全问题，Na树枝状晶体的连续繁殖普遍阻碍了其实施。在此，AlF ₃的涂层第一次被装饰在阳极阳极和NASICON SSE之间，其可以在初始循环中通过与Na的转化反应原位形成Na ⁺导电缓冲层。受益于AlF ₃中间层的紧密修饰，Na / SSE界面接触得到了极大的改善。此外，由于AlF ₃之间的反应的“过电位触发”机制和Na，可以通过优先驱动更多的Na ⁺与AlF ₃反应而不是在大电流密度下形成树枝状晶体来释放阳极-电解质界面处的局部电子。根据DFT计算，由于AlF ₃诱导的夹层与Na之间的界面能增加，因此临界枝晶的长度也增大了。因此，Na / AlF ₃ -NASICON / Na电池的临界电流密度在60°C时增加了三倍，达到1.2 mA cm ^-2，并且Na金属SSE电池的循环稳定性也得到了显着改善。修改AlF ₃的合理策略 中间层被认为有助于抵抗树枝状晶体在固体碱金属电池之间的传播。