Highly Flexible PEDOT Film Assembled with Solution-Processed Nanowires for High-Rate and Long-Life Solid-State Supercapacitors

• Published in: ACS sustainable chemistry & engineering Vol. 11; no. 7; pp. 2938 - 2948
• Main Authors: Han, Xiying, Sun, Jie, Li, Qi, He, Xuexia, Dang, Liqin, Liu, Zonghuai, Lei, Zhibin
• Format: Journal Article
• Language: English
• Published: American Chemical Society 20.02.2023
• Subjects: high-rate performance; oxidative polymerization; thick-film electrode; PEDOT nanowires; supercapacitor
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.2c06423

Self-supporting highly conductive polymers are strongly demanded for high-rate flexible supercapacitors. In this work, we demonstrate that solution-processed poly­(3,4-ethylenedioxythiophene) (PEDOT) nanowires with tens of micrometers in length can facilely assemble into highly flexible PEDOT films for high-rate supercapacitors. Our results show that the conductivity of the films (50.8–100 S cm–1) relies on the polymerization time of the nanowires and longer time favors doping of dodecyl sulfate anions but results in a decrease of carrier mobility from 16.08 to 6.05 cm2 V–1 s–1. A specific capacitance of 137 F g–1 along with 98% capacitance retention after 10 000 cycles has been achieved in 1 M H2SO4. Moreover, due to the favorable ion and electron pathways and rapid pseudocapacitive redox reactions, these PEDOT films exhibit nearly thickness-independent capacitive performance even as the film thickness increases up to 100 μm. A solid-state capacitor built with a PEDOT film delivers an energy density of 1.38 mWh cm–3 at 27.9 mW cm–3. Meanwhile, it also exhibits superior long-term electrochemical stability without obvious capacitance decay and excellent structural integrity under various deformation tests. These outstanding properties demonstrate that the PEDOT nanowires could become one of the promising building blocks for developing flexible electrodes with an interconnected network for future high-rate energy storage devices.