Robust and Highly\nConductive Cellulose-Based Eutectogel\nfor Flexible Electronics

High-performance\nionic conductive gels are essential\nfor the development\nof flexible electronic devices. However, the robustness and conductivity\nof gel materials are compromised at extreme temperatures. In this\nstudy, a high-performance eutectogel composed of cellulose and metal-based\ndeep eutectic solvent (DES) was prepared. Specifically, cellulose\nwas dissolved in a ternary DES (ZnCl<sub>2</sub>/water/citric acid)\nat room temperature, and then another polymerizable DES (ZnCl<sub>2</sub>/acrylic acid) was introduced to prepare eutectogels with\nmultiple cross-linking hydrogen bonds. In such a design, the as-obtained\neutectogels display a decent mechanical performance (tensile stress\nup to 1.43 MPa) and superior ionic conductivity (5.51 S m<sup>–1</sup>). Furthermore, their excellent environmental adaptability allows\ntheir use across a wide range of temperatures from −45 to +95\n°C. Eutectogel-based wearable multifunctional sensors are highly\nresponsive to both tensile and compressive deformation, monitor human\nmovement, and transmit stable and tunable electrical signals. As a\nsolid-state eutectogel-based electrolyte, the assembled supercapacitor\nhas a wide operating voltage window of 2.2 V and a high specific capacitance\nof 143.2 F g<sup>–1</sup> at a current density of 0.5 A g<sup>–1</sup>. This work provides an idea for designing green and\nflexible gel-based electronic devices.