Inorganic–Organic Hybrid Multifunctional Solid Electrolyte Interphase Layers for Dendrite‐Free Sodium Metal Anodes

Abstract Constructing a stable and robust solid electrolyte interphase (SEI) is crucial for achieving dendrite‐free sodium metal anodes and high‐performance sodium batteries. However, maintaining the integrity of SEI during prolonged cycle life under high current densities poses a significant challenge. In this study, we propose an integrated multifunctional SEI layer with inorganic/organic hybrid construction (IOHL−Na) to enhance the durability of sodium metal anode during reduplicative plating/stripping processes. The inorganic components with high mechanical strength and strong sodiophilicity demonstrate optimized ionic conduction efficiency and dendrite inhibition ability. Simultaneously, the organic component contributes to the formation of a dense and elastic membrane structure, preventing fracture and delamination issues during volume fluctuations. The symmetrical batteries of IOHL−Na achieve stable cycling over 2000 hours with an extremely low voltage hysteresis of around 15.8 mV at a high current density of 4 mA cm −2 . Moreover, the Na−O 2 batteries sustain exceptional long‐term stability and impressive capacity retention, exploiting a promising approach for constructing durable SEI and dendrite‐free sodium metal anodes.