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

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-O₂ batteries sustain exceptional long-term stability and impressive capacity retention, exploiting a promising approach for constructing durable SEI and dendrite-free sodium metal anodes.