Reflex Charging for Anion‐Derived Solid Electrolyte Interphase Formation

ABSTRACT Lithium (Li) metal offers exceptional energy density but suffers from unstable interphases that lead to dendrite growth and poor reversibility. Because the interphase is established during the earliest stages of operation, controlling its formation is critical for stabilizing Li metal electrodes. Here, we demonstrate that a reflex charging strategy, in which short discharge pulses are introduced during charging, dynamically reprograms the interfacial environment. This approach sustains anion enrichment near the electrode surface and shifts Li + solvation from solvent‐dominated structures toward anion‐coordinated structures, thereby promoting the formation of an inorganic‐rich interphase. The resulting interphase reduces interfacial resistance and enables dense and uniform Li deposition. Consequently, the reflex charging‐based formation protocol exhibits markedly improved Li depo…