Anion‐Managing Biomimetic Electrolyte Based on Fluorinated COF Recognition and Hyperbranched Polyamidoamine Capture for Practical Lithium–Metal Batteries

Abstract

ABSTRACT Solid polymer electrolytes (SPEs) hold great promise for next‐generation high‐safety lithium batteries, yet their development is fundamentally constrained by the inherent dilemma of poor ion transport and unstable electrode–electrolyte interfaces. To address the challenge, the biomimetic ion‐management strategy termed “recognition‐capture” strategy, inspired by the synergistic predation behavior of grouper and moray eel, is proposed. The covalent organic framework (COF) with ordered nanochannels is designed as the “moray eel” to recognize, enrich, and guide TFSI − anions, while the hyperbranched polyamidoamine (PAMAM) with dense amine groups serves as the “grouper” to deeply anchor and lock the anions. Therefore, the created composite electrolyte TFPL simultaneously achieves ionic conductivity of 4.5 mS cm −1 and t Li+ of 0.7. Moreover, the biomimetic “recognition‐capture” strategy induces the spontaneous formation of the stable gradient interphase (Li 3 N─Li 2 S─LiF/LiH), which homogenizes Li + flux and suppresses dendrite. Consequently, Li||Li cells achieve stable cycling exceeding 1800 h. The TFPL electrolyte enables LFP cells to cycle stably for 450 cycles at 5 C, delivers over 240 mAh g −1 for NCM811 cell at 4.5 V, and offers 9.37 mAh for NCM523 pouch cells at 0.1 C. The strategy also proves effective in Li─S cell, demonstrating the broad applicability for next‐generation solid‐state lithium–metal batteries.