Li−N Interaction Induced Deep Eutectic Gel Polymer Electrolyte for High Performance Lithium‐Metal Batteries

Abstract

AbstractAs emerging eutectic mixtures, deep eutectic electrolytes (DEEs) show unique properties for Li‐metal batteries (LMBs). However, the limited choice and inferior electrode compatibility hinder their further development in LMBs. Herein, we report a new 1,2‐dimethylimidazole (DMIm)‐based deep eutectic gel polymer electrolyte induced by Li−N interaction. We demonstrate that incorporating electron‐withdrawing polyvinylidene difluoride (PVDF) polymer into the DMIm‐based DEE changes the coordination environment of Li+ ions, leading to a high transference number of Li+ ions (0.65) and superior interface stability between the electrolyte and Li anode. The deep eutectic gel polymer electrolyte exhibits excellent non‐flammability, high ionic conductivity (1.67 mS cm−1 at 30 °C), and high oxidation voltage (up to 4.35 V vs. Li/Li+). The Li||LFP cell based on the newly developed deep eutectic gel polymer electrolyte can achieve superior long‐term cycling stability at a wide range of rates.