Vertically Aligned Li + Transport Interfaces for Fast‐Charging Quasi‐Solid‐State Batteries

ABSTRACT Gel polymer electrolytes (GPEs) hold promise for lithium metal batteries because they are processable and can form conformal electrode contact. However, tortuous ion‐transport pathways and pronounced interfacial polarization severely constrain fast‐charging capability. Herein, a vertically aligned ion transport interface is constructed via a single‐step dopamine‐regulated phase inversion strategy, designed to couple low‐tortuosity pathways with solvation‐tuning chemistry for efficient transport and interfacial regulation. During phase inversion, dopamine simultaneously drives rapid demixing to generate finger‐like vertical channels, stabilizes the polar β‐PVDF‐HFP framework via dipole interactions, and oxidatively polymerizes to enrich the pore walls with Lewis‐basic catechol/amine sites. Theoretical simulations and 7 Li ssNMR reveal that the high‐dielectric framework within vertically aligned pores provides low‐tortuosity pathways and low Li + migration barrier for rapid ion transport, while Lewis‐basic pore walls modulate Li + solvation to weaken anion association, thereby homogenizing Li + flux and suppressing concentration polarization. Consequently, the electrolyte exhibits high ionic conductivity of 1.2 × 10 −3 S cm −1 and Li + transference number of 0.666. It enables stable cycling of symmetric cells for over 2500 h and supports LiFePO 4 full cells with operation even at ultrahigh rates up to 20 C. A small molecule enables one‐step tri‐functionalization to build ion‐transport interface for fast‐charging quasi‐solid‐state lithium metal batteries.