Mechanically Strong and Tough Organohydrogels for Wide Temperature Tolerant, Flexible Solid‐State Supercapacitors

Abstract

AbstractHydrogel‐based flexible solid‐state supercapacitors (SSCs) hold great promise for wearable electronics, yet significant challenges persist in simultaneously achieving excellent mechanical properties, high ionic conductivity, outstanding electrochemical properties, and wide operating temperature ranges. Here, this study presents a straightforward method for synthesizing dual crosslinked polyvinyl alcohol‐polyimide (PVA‐PI) organohydrogels via a simple one‐pot synthesis followed by a freezing‐thawing process. The controlled dual crosslinked networks with significanonetly different crosslinking densities and robust intermolecular hydrogen bonding interactions facilitated by the macromolecular crosslinker of PI, endow the organohydrogels with both high mechanical properties and ionic conductivity. Furthermore, SSCs based on PVA‐PI organohydrogels are fabricated, which can exhibit outstanding electrochemical performance at temperatures ranging from −40 to 80 °C. Specifically, the energy density reaches 16.7 µWh cm−2 even at −40 °C under a power density of 410.0 µW cm−2. These SSCs also show excellent performance stability under various deformations, such as bending and compression, alongside exceptional long‐term cycling stability (over 10 000 cycles) with high capacitance retention from −40 to 50 °C. The synthesis strategy, along with a robust mechanism for enhancing mechanical properties of hydrogels, demonstrated in this study offers insights for the development of strong hydrogels/organohydrogels with broad temperature adaptability for soft electronic applications.