Robust Solid Electrolyte Interphase Engineered by Catalysis Chemistry Toward Durable Anode‐Free Sodium Metal Batteries

Abstract Anode‐free sodium metal batteries (AFSMBs) are considered one of the most promising large‐scale energy storage systems due to their extremely high energy density. Nonetheless, their practical application is hindered by the uncontrolled growth of sodium dendrites. Constructing a mechanically robust solid electrolyte interphase (SEI) is an effective strategy to suppress dendrite formation. Herein, we report a catalysis chemistry approach to construct an ultra‐thin (∼ 5 nm), NaF‐rich and high‐strength (203 MPa) SEI layer by introducing Ru catalytic sites on the current collector, which promotes rapid Na⁺ diffusion and effectively inhibits dendrite growth. Benefiting from this design, the Ru modified‐Cu//Na asymmetric cells exhibit exceptional cycling stability over 2000 h (1000 cycles at 2 mA cm −2 , 2 mAh cm −2 ). Furthermore, the AFSMBs with Ru modified‐Cu current collector also deliver excellent cycling performance and maintains nearly 98.1% capacity retention after 100 cycles at 0.5 C. The results demonstrate great potential of catalysis chemistry in developing advanced sodium metal anodes and provide a new perspective to engineering efficient SEI toward battery applications.