The Role of Interfaces in Ionic Liquid‐Based Hybrid Materials (Ionogels) for Sensing and Energy Applications
Ji Wei Suen, Naveen Kumar Elumalai, Sujan Debnath, Nabisab Mujawar Mubarak, Chye Ing Lim, Mohan M. Reddy
Abstract
Abstract Ionogels have established themselves as an intriguing type of composites, owing to their distinctive properties, including superior thermal stability, non‐flammability, tunable electrochemical stability window, and high ionic conductivity. Hybrid materials based on ionic liquids (ionogels) are held together by interfaces arising out of intermolecular interactions, including electrostatic, van der Waals, solvophobic, steric, and hydrogen bonding. The interfaces within the ionic liquid (ILs) and its multifaceted interplay with the encapsulating matrix greatly influence the physicochemical and electronic/ionic interactions within the composite resulting in exceptional characteristics, allowing for the design of ionogels for targeted applications. Though ionogels have shown superior properties comparable to neat ILs, they still exhibit relatively low mechanical strength, limiting their application in several practical technologies. Simultaneous enhancement of mechanical durability while retaining high ionic conductivity is indispensable, which requires understanding interfaces and related influencing parameters. This review provides a synergetic comprehension, focusing on the interactive forces and factors affecting the conductivity, stability, and robustness of ionogels. Correlating with interfaces, several strategies, including the implications of nanofiller incorporation on the electromechanical properties of ionogel, are also elaborated. Finally, a primer is provided on the application of ionogels in sensors and energy harvesting technologies.