NASICON-structured NaZrSiPO (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 FeO not only improves ionic conductivity and reduces activation energy by the doping of Fe 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 Fe in the interface is reduced Fe 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 1,500 h at 0.1 mA·cm/0.1 mA·h·cm and over 900 h at 0.2 mA·cm/0.2 mA·h·cm. The Na|NZSP-0.075%FeO|NaFePOF 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.

中文翻译：

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Fe2O3 同时增强固态钠金属电池的离子电导率和界面稳定性


NASICON结构的NaZrSiPO（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，FeO的引入不仅通过在NZSP晶体结构中掺杂Fe提高了离子电导率并降低了活化能，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还原，有效均匀电场分布，抑制枝晶生长。因此，对称固态电池在0.1 mA·cm/0.1 mA·h·cm下表现出稳定的循环性能1,500小时，在0.2 mA·cm/0.2 mA·h·cm下表现出超过900小时的稳定循环性能。 Na|NZSP-0.075%FeO|NaFePOF固态全电池在0.5 C下循环100次后，容量保持率高达94.2%。NZSP/Na稳定的界面和改进的离子电导率有助于实现优异的电化学性能，从而加速实际应用。 ASSSB 的应用。