Rapid Preparation\nof Antifreezing Conductive Hydrogels\nfor Flexible Strain Sensors and Supercapacitors

Abstract

Conductive hydrogels have shown great promise in flexible\nelectronics,\nbut their practical applications may be impeded by the time-consuming\nand energy-consuming polymerization process. We proposed a sodium\nlignosulfonate–Fe (SLS–Fe) strategy to address this\nchallenge and took advantage of carboxymethyl cellulose (CMC) and\npoly(acrylic acid) to prepare the CMC/PAA/Fe³⁺/LiCl interpenetrating\nconductive hydrogels with good self-healing properties, antifreezing\nproperties, and a 6-fold increase in conductivity in this study. The\nhydrogel-based flexible strain sensors demonstrated a broad detection\nrange (400%), high sensitivity (GF = 6.19 at 200–400%), and\nhuman motion detection capability. The hydrogel-based supercapacitor\nexhibited a single-electrode specific capacitance of 122.36 F g^–1 which successfully powered LEDs. Furthermore, the\nsupercapacitor showed a single-electrode specific capacitance of 83.16\nF g^–1 at −23 °C (68% of the one exhibited\nat 25 °C). Therefore, the multifunctional performance of the\nCMC/PAA/Fe³⁺/LiCl hydrogel is anticipated to play an exemplary\nrole in a new generation of flexible electronics.