Flexible Supercapacitor Based on Organohydrogel Electrolyte with Long‐Term Anti‐Freezing and Anti‐Drying Property

Abstract Hydrogel electrolytes have spurred the development of flexible energy storage devices by endowing them with liquid‐like ion transport and solid‐like mechanical elasticity. However, traditional hydrogel electrolytes always lose these functions in climate change because the internal water undergoes freezing and/or dehydration. In this work, a flexible supercapacitor (OHEC) is assembled based on the organohydrogel electrolyte (OHE) and activated carbon electrode material. The OHE is composed of PAMPS/PAAm double‐network hydrogel soaked from 4 m LiCl/ethylene glycol and exhibits good conductivities (1.9 and 22.9 mS cm −1 at −20 and 25 °C, respectively). The OHEC exhibits broad temperature adaptability (from −20 to 80 °C) and extraordinary resistance to mechanical damage (above 100 kg crushing). The OHEC avoids the polarization at low temperatures and retains 77.8% capacitance retention after storage at −20 °C for 30 days. Without extra sealed packaging, the OHEC maintains remarkable cycling stability (only 8.7% capacitance decay after 10 000 cycles) and retains 77.3% capacitance at 80 °C after 56 h. The outstanding anti‐drying performance and improved interfacial compatibility of OHEC account for the good durability in the high‐temperature environments. Additionally, other salts (such as LiClO 4 , NaCl, and KCl) with favorable solubility in ethylene glycol can also serve in OHEs for wide temperature range supercapacitors.