LiF‐Rich Solid Electrolyte Interphase Formation by Establishing Sacrificial Layer on the Separator

Abstract The formation of a stable solid electrolyte interphase (SEI) layer is crucial for enhancing the safety and lifespan of Li metal batteries. Fundamentally, a homogeneous Li + behavior by controlling the chemical reaction at the anode/electrolyte interface is the key to establishing a stable SEI layer. However, due to the highly reactive nature of Li metal anodes (LMAs), controlling the movement of Li + at the anode/electrolyte interface remains challenging. Here, an advanced approach is proposed for coating a sacrificial layer called fluorinated self‐assembled monolayer (FSL) on a boehmite‐coated polyethylene (BPE) separator to form a stable SEI layer. By leveraging the strong affinity between the fluorine functional group and Li + , the rapid formation of a LiF‐rich SEI layer in the cell production and early cycling stage is facilitated. This initial stable SEI formation promotes…