Nanocomposite Ionogel Electrolytes for Solid‐State Rechargeable Batteries

Ionogels composed of ionic liquids and gelling solid matrices offer several advantages as solid‐state electrolytes for rechargeable batteries, including safety under diverse operating conditions, favorable electrochemical and thermal properties, and wide processing compatibility. Among gelling solid matrices, nanoscale materials have shown particular promise due to their ability to concurrently enhance ionogel mechanical properties, thermal stability, ionic conductivity, and electrochemical stability. These beneficial attributes suggest that ionogel electrolytes are not only of interest for incumbent lithium‐ion batteries but also for next‐generation rechargeable battery technologies. Herein, recent advances in nanocomposite ionogel electrolytes are discussed to highlight their advantages as solid‐state electrolytes for rechargeable batteries. By exploring a range of different nanoscale gelling solid matrices, relationships between nanoscale material structure and ionogel properties are developed. Furthermore, key research challenges are delineated to help guide and accelerate the incorporation of nanocomposite ionogel electrolytes in high‐performance solid‐state rechargeable batteries. As a solid‐state electrolyte for rechargeable batteries, nanocomposite ionogels based on ionic liquids and nanoscale gelling matrices offer distinct advantages for ionic conductivity, mechanical properties, and thermal and electrochemical stability. This essay delineates recent developments for nanocomposite ionogel electrolytes in the context of next‐generation solid‐state rechargeable batteries in addition to outlining remaining challenges and future research directions.