Room temperature sodium-sulfur batteries possess higher specific energy and improved inherent safety compared to their high-temperature analogs used in stationary grid storage. The viability of room temperature sodium batteries depends critically on the mechanical and ionic transport properties of the solid electrolyte interphase. However, little emphasis has been placed on developing sodium anode interphases that combine high Young’s modulus (stiffness), high critical strain (ductility), and low ionic diffusion barrier for cycling at high rates. Here, we report an artificial biphasic interphase comprising two chemically distinct phases, NaOH and NaNH₂, which combines high stiffness and high ductility. In addition, the biphasic interphase exhibits a low diffusion barrier for sodium ions, enabling reversible sodium plating and stripping behavior even at extremely high current densities (up to 50 mA cm⁻²) in symmetric cell configuration. Stable and reversible cycling of a room temperature sodium-sulfur battery is also demonstrated over 500 cycles.

与用于固定电网存储的高温类似物相比，室温钠硫电池具有更高的比能和更高的固有安全性。室温钠电池的生存能力主要取决于固体电解质相间的机械和离子传输性能。但是，很少有人集中精力开发钠阳极相，这些相结合了高杨氏模量（刚度），高临界应变（延展性）和低离子扩散势垒，从而可以高速循环。在这里，我们报告了一个人工双相中间相，包括两个化学上不同的相NaOH和NaNH ₂，兼具高刚度和高延展性。另外，双相界面对钠离子表现出低的扩散势垒，即使在对称电池配置中的极高电流密度（高达50 mA cm ^-2）下，也能实现可逆的钠电镀和剥离行为。还证明了室温钠硫电池的稳定和可逆循环超过500个循环。