NASICON-structured Na₃Zr₂Si₂PO₁₂ (NZSP) has been considered as one of the ideal electrolytes for all-solid-state sodium metal batteries (ASSSB). However, the practical application of NZSP-based ASSSB is hindered by the low ionic conductivity and large interfacial resistance caused by the poor contact between NZSP and Na metal. Herein, the introduction of Fe₂O₃ not only improves ionic conductivity and reduces activation energy by the doping of Fe³⁺ in the crystal structure of NZSP, but also reduces the interfacial resistance and enhances interface stability between NZSP and Na metal anode. The synergistic effects significantly enhance the cycling stability, rate capability, and critical current density of the symmetrical solid-state cells. The interfacial reaction mechanism indicates that Fe³⁺ in the interface is reduced Fe²⁺ by Na anode, which effectively even the electric-filed distribution and suppresses the dendrite growth. Consequently, the symmetric solid-state cells exhibit stable cycling performance for 1500 h at 0.1 mA·cm⁻¹/0.1 mA·h·cm⁻¹ and over 900 h at 0.2 mA·cm⁻¹/0.2 mA·h·cm⁻¹. The Na|NZSP-0.075%Fe₂O₃|Na₂FePO₄F solid-state full cells display high capacity retention of 94.2 % after 100 cycles at 0.5 C. The stable interface of NZSP/Na and improved ionic conductivity contribute to excellent electrochemical performance, which accelerates the practical application of ASSSB.

NASICON结构的Na ₃ Zr ₂ Si ₂ PO ₁₂ (NZSP)被认为是全固态钠金属电池(ASSSB)的理想电解质之一。然而，NZSP基ASSSB的实际应用受到NZSP与Na金属接触不良导致的低离子电导率和大界面电阻的阻碍。_{其中，Fe 2} O ₃的引入不仅通过在NZSP晶体结构中掺杂Fe ^{3+来提高离子电导率并降低活化能，而且还降低了界面电阻并增强了NZSP与Na金属负极之间的界面稳定性。}协同效应显着提高了对称固态电池的循环稳定性、倍率性能和临界电流密度。界面反应机理表明，Na阳极将界面中的Fe ³⁺还原为Fe ²⁺，有效均匀了电场分布，抑制了枝晶生长。因此，对称固态电池在0.1 mA·cm ^-1 /0.1 mA·h·cm ^{-1下表现出稳定的循环性能1500小时，在0.2 mA·cm -1} /0.2 mA·h·cm -1下表现出超过900小时的稳定循环性能^{。 1} . Na|NZSP-0.075%Fe ₂ O ₃ |Na ₂ FePO ₄ F 固态全电池在 0.5 C 下循环 100 次后显示出 94.2 % 的高容量保持率。NZSP/Na 的稳定界面和改进的离子电导率有助于实现优异的性能。电化学性能，加速了ASSSB的实际应用。