Pore Electrostatic Reconstruction in Ionic COF for Li + Transport and Interface Stability

Ionic COF solid-state electrolytes offer ordered charged channels, but Li + −anion association, unstable Li interphases, and cathode-side polarization remain challenges. Here, we develop a pore electrostatic reconstruction strategy to coordinately regulate bulk Li + transport and interfacial electrochemistry. TFSI − is directionally introduced into cationic COF channels via ion exchange (ION-TFSI-COF), giving rise to a localized electrostatic environment with multilevel polarization. Through cation−anion electrostatic coupling and local charge redistribution, Li + −TFSI − coordination is weakened, while TFSI − polarization is promoted, enabling Li + -selective transport. The polarized TFSI − favors LiF-rich interphase formation on Li metal and maintains continuous Li + flux to reduce cathode-side charge accumulation and space charge layer polarization, thereby coupling intrachannel transport with dual-interface compatibility. The optimized electrolyte delivers 8.5 × 10 −4 S cm −1 conductivity, a t Li+ of 0.83, 91% retention in Li||LFP cells over 1300 cycles at 2C, and durable Li||NCM811/NCM90 cycling, highlighting pore electrostatic reconstruction as a design strategy for COF solid-state electrolytes.