Versatile Ionic Liquids: Bridging Biomass Dissolution and Battery Material Innovation

The search for environmentally benign solvents capable of processing
renewable polymers has accelerated interest in ionic liquids (ILs)—
salts that remain liquid at low temperatures and display remarkable
tunability. This chapter explores the dual functionality of
imidazolium-based ionic liquids, particularly 1-butyl-3-
methylimidazolium chloride ([BMIM]Cl), in (i) dissolving recalcitrant
cellulose and (ii) producing ionic-liquid-incorporated cellulose films
suitable for electrochemical devices. Cellulose, the most abundant
biopolymer on Earth, resists dissolution because of its crystalline
hydrogen-bonded network. ILs overcome this limitation by disrupting
intermolecular hydrogen bonds while simultaneously imparting ionic
conductivity to regenerated films. The chapter details the synthesis
of [BMIM]Cl, preparation of cellulose and IL-incorporated cellulose
films, and their characterization using NMR, FT-IR, SEM, and XRD
analyses. Results reveal that IL incorporation decreases film crystallinity, enhances amorphous character, and promotes
morphological uniformity—features conducive to solid-state electrolyte behaviour. By connecting biomass dissolution chemistry
with energy-storage material design, this work highlights ionic liquids
as versatile tools for advancing sustainable battery technologies.