A Phase-Separated Cellulose-Ionogel via Sunlight-Initiated Green Fabrication for Self-Powered Wearable Sensors

Ionogels, as soft ionic conductors, face synthesis challenges including toxicity, complexity, and high energy consumption. Herein, we present a green one-pot strategy that effectively dissolves cellulose and undergoes sunlight-induced photopolymerization to form ionogels without the need for cross-linkers or initiators. 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl), as the solvent, enables the disruption of the extensive hydrogen-bond network of cellulose, resulting in rapid and complete dissolution. Subsequent one-step photopolymerization, which proceeds solely under sunlight, simultaneously drives in situ cross-linking and a controlled phase separation process, yielding high-performance ionogels. Importantly, the resulting cellulose ionogel exhibits superior fracture strength (2.75 MPa), high toughness (18.4 MJ m^-3), and strong adhesion (6.6 MPa), ameliorating the traditional trade-off between mechanical strength and adhesion capabilities. This work develops an integrated ionogel platform as a soft TENG electrode for human motion monitoring, informing the design of sustainable self-powered electronics.