The Polymer Society of Korea

Abstract

Lithium metal batteries (LMBs) are promising energy storage system due to their high energy density, but their practical application is hindered by lithium dendrite growth and safety concerns. Gel polymer electrolyte (GPEs) offer a alternative solution by mechanically suppressing dendrites, yet often exhibit low ionic conductivity and high interfacial resistance due to strong Li⁺ solvation and sluggish ion transport. In liquid systems, F-containing diluent with low dielectric constants have been explored to mitigate this issue. Herein, we address the challenges of conventional GPEs by covalently incorporating an F-diluent into the polymer matrix. This reduces Li⁺ solvation strength and promotes faster ion hopping, while the fluorinated environment induces an anion-rich solvation structure that facilitates the formation of a robust, LiF-rich SEI layer. This SEI layer stabilizes Li⁺ flux and effectively suppresses dendrite growth. Moreover, the high oxidative stability of the F containing polymer enables reliable battery operation. This molecular-level GPE design can enhance ionic conductivity and electrochemical stability in LMB.