Cellulose-Derived Water-Free, Anti-Freezing, and Self-Initiated Ionogel for Flexible Wearable Electronics

The growing demand for sustainable flexible electronics has positioned cellulose as a promising candidate, yet its efficient dissolution and functionalization remain challenging due to its highly crystalline structure and strong intermolecular hydrogen bonding. While a wide variety of cellulose dissolution systems have been reported in the literature, most systems still depend on toxic initiators or complex processes. Herein, we report a sunlight-driven, initiator-free green synthesis of cellulose-based ionogels that enables direct cellulose dissolution and in situ photopolymerization, which provides a facile and sustainable route to anti-freezing ionogels via the direct in situ polymerization of ionogel precursors without initiators or crosslinkers. Notably, the incorporation of cellulose, along with the intrinsic properties of the 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and ethylene glycol (EG) significantly enhanced the mechanical properties of the conductive ionogel, which exhibited outstanding mechanical performance (fracture strain of 935%, fracture stress of 166.5 kPa), robust adhesive properties (1.48 MPa), excellent conductivity (0.028 mS·cm–1) and wide work temperature range (–20∼60 °C). These properties enabled the ionogel to function not only as a wearable strain sensor for motion detection but also as a self-powered controller for operating a remote-controlled car via human-computer interaction. This work provides a versatile and sustainable strategy for fabricating high-performance cellulose ionogels, paving the high value-added way for future soft electronic systems with multifunctional integration.