High‐Performance Deep Eutectic/Ionic Liquid Gels for Zinc‐Ion Battery and Flexible Sensor Applications in Extreme Environments

Abstract Due to the remarkable flexibility and high safety of gel electrolytes, they have garnered significant attention in the fields of batteries and beyond. However, limitations such as low ionic conductivity, poor environmental adaptability, and a propensity for side reactions at interfaces hinder their practical application. In this study, a deep eutectic solvent/ionic liquid composite gel (PDEM) is synthesized via a one‐pot method. Leveraging extensive dynamic hydrogen bonding and ionic interactions between deep eutectic solvents, ionic liquids, and polymer matrices, the activity of free water is effectively suppressed. This results in the PDEM exhibiting exceptional flexibility (tensile deformation up to 2500%) and anti‐freezing properties (freezing point at −49 °C). Furthermore, the water‐poor Zn 2+ solvation structures effectively inhibit the hydrogen evolution reaction and dendrite growth in zinc‐ion batteries. The assembled Zn||PDEM||VO 2 flexible battery exhibits deformation resistance and excellent environmental adaptability under extreme conditions (−20 °C). The Zn||PDEM||Zn symmetric battery demonstrates stable cycling performance for 1003 h at a current density of 2.0 mA cm −2 . Moreover, the PDEM performs admirably in flexible sensing applications, offering a novel approach for the development of next‐generation flexible solid electrolytes.