Hydrogen-Bond and Solvation-Shell Dual Modulation Enables Safe Gel Polymer Electrolyte for Lithium Metal Batteries.

Gao, Xinran; Zheng, Cheng; Li, Rui; Liu, Hongmin; Wang, Mingyue; Shang, Zhichao; Wang, Chunting; Xuan, Wufan et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

Lithium metal batteries promise ultrahigh energy density but suffer from interfacial instability, dendrite growth, and safety risks. Gel polymer electrolytes are a promising solution, but conventional designs suffer from poor interfacial compatibility and lithium dendrite growth. Here, we design an <i>in situ</i> formed nonflammable gel polymer electrolyte (NGPE) that integrates two molecular-level strategies: hydrogen-bond anchoring and solvation-shell regulation. Hydrogen bonds among TMP, PVDF-HFP, and TFSI<sup>-</sup> immobilize anions, enhancing ionic conductivity and Li<sup>+</sup> transference. Fluoroethylene carbonate reshapes Li<sup>+</sup> solvation, leading to the formation of inorganic-rich interphases that suppress dendrites and stabilize interfaces. The optimized NGPE achieves stable Li||Li cycling for over 2800 h and Li||LFP full cells with 74.3% capacity retention after 1000 cycles at 2 C. Pouch cells further demonstrate mechanical robustness and exceptional safety under flame tests. This dual molecular strategy provides a general design principle for safe, dendrite-free quasi-solid-state lithium metal batteries.