Extreme Temperature-Tolerant Organohydrogel Electrolytes for Laminated Assembly of Biaxially Stretchable Pseudocapacitors

Polymer gel electrolytes (PGEs) have been considered as one of the most promising candidates to solve safety and flexibility issues in wearable devices. To supply energy for the daily-used epidermal electronic systems, biaxial stretchability and temperature tolerance are essential for energy storage units. However, the limited choices of PGEs, including fragile poly(vinyl alcohol) and uniaxial stretchable polyacrylamide hydrogel, lag far behind the requirement of wearable supercapacitors. Herein, an adhesive organohydrogel with a water/ethylene glycol binary solvent is tailored as the electrolyte of an all-climate, biaxially stretchable pseudocapacitor. The adhesive organohydrogel electrolyte facilitates the device assembly with carbon nanotube (CNT) paper electrodes and electroactive 2-pyridinethiol. The final pseudocapacitor has the highest specific capacitance 364 F/g and all-climate stability ranging from -40 to 80 °C. More importantly, this pseudocapacitor can be biaxially stretched up to 400% of its area. This work provides the first example of using organohydrogel electrolytes in biaxially stretchable and all-climate pseudocapacitors and a platform to design stretchable electronics and devices with high performance and all-climate tolerance.