Ionic liquid gel polymer electrolytes for flexible supercapacitors: Challenges and prospects

Ionic liquid gel polymer electrolytes (IL-GPEs) have attracted wide interest in the field of electrochemical energy storage devices, particularly for their use in flexible supercapacitors (FSCs). IL-GPEs integrate ionic liquids (ILs) as either a solvent or as a polymerizable unit. They possess several attractive properties including high ionic conductivity, wide operating potential range, good thermal stability, tunable chemical functionalities and self-healing capabilities. In this short review, an overview of IL-GPEs is provided, first describing their classification, fundamental properties, and chemical design, then detailing some of the most recent essential advances in the field along with their limitations. • Flexible supercapacitors are desirable due to light weight, flexibility, and comfort when wearing. • Ionic liquid gel polymer electrolytes (IL-GPEs) open up new possibilities for multi-functional FSCs. • This mini-review paper describes recent advancements of IL-GPEs used in FSCs over the past three years. • Selecting a specific IL for a given gel scaffold material is crucial when exploring new FSC materials.