Sodium metal batteries (SMBs) represent a promising next-generation energy storage technology due to their low cost and high energy density. However, SMBs face significant challenges, including interfacial instability and the growth of sodium dendrites on the metal anode, particularly at low temperatures (LTs). Poor ion desolvation at LTs further exacerbates these issues, severely compromising battery performance. To address these problems, a heterogeneous artificial solid electrolyte interphase (SEI) composed of Na3VO4 and metallic In (NVO-In@Na) is designed for LT SMBs. The sodiophilic Na3VO4 promotes sodium ion adsorption, while the Na2In phase formed during the initial plating enhances ion transport kinetics, resulting in uniform Na deposition behavior. Theory calculations indicate that the Na3VO4/Na2In interface accelerates charge transfer processes and desolvation. The engineered NVO-In@Na anode demonstrates exceptional stability: symmetric cells operate for over 2000 h at 0.5 mA cm-2/1 mAh cm-2 under ambient conditions and exceed 1100 h at 0.1 mA cm-2/0.1 mAh cm-2 at -40 °C. Full cells paired with Na3V2(PO4)3 (NVP) cathode retain 97% capacity after 1150 cycles at 0.5 C and -40 °C. This work highlights the potential of rational SEI design to overcome critical limitations of SMBs, advancing high-performance energy storage under extreme conditions.
Keywords: Na+ desolvation; eterogeneous interphase layers; low‐temperature performance; sodium metal batteries.
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