All-glycerogel stretchable supercapacitor with stable performance in a wide temperature window from −20 to 80 °C

Abstract

Stretchable supercapacitors (s-SCs) are extensively used in portable and wearable smart electronic devices. However, existing s-SCs exhibit low electrical conductivity/stretchability, weak electrode/electrolyte interfaces, and limited operational temperatures, which severely limit their practical applications. Accordingly, we have developed a stretchable glycerogel supercapacitor (s-GGSC) addressing these limitations. Electrode is fabricated by glycerol-mediated robust integration of poly(vinyl alcohol) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate through a simple strategy of partial drying–reswelling and thermal annealing. This eliminates the conventional trade-off between electrical conductivity and stretchability and provides adaptability to wide temperature ranges (−20 to 80 °C). A compatible electrolyte is also fabricated using poly(vinyl alcohol), lithium perchlorate, and glycerol. Heat-mediated facile exchange of inter- and intramolecular hydrogen bonding enables robust bonding between the electrode and electrolyte in the developed s-GGSC, thus solving interfacial problems under harsh mechanical conditions. The high electrical conductivity (1089 ± 49 S m−1) and fracture strain (232%) of the electrode preclude the use of an additional current collector. s-GGSC exhibits areal capacitance retentions of 90.92% and 93.27% after 7 d of incubation at −20 and 80 °C, respectively, and excellent cycling stability (81.48% capacitance retention) after 10,000 cycles. Furthermore, the areal capacitance of the device remains constant after intense mechanical deformations, such as bending, twisting, and stretching. s-GGSC outperforms existing flexible and/or stretchable supercapacitors under harsh conditions, confirming its suitability as a potential power source for wearable and stretchable smart electronic devices.