A Regenerable Hydrogel Electrolyte for Flexible Supercapacitors

• Published in: iScience Vol. 23; no. 9; p. 101502
• Main Authors: Zhou, Guanbing, Yang, Leyi, Li, Weijun, Chen, Chongyi, Liu, Qiao
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 25.09.2020; Elsevier
• Subjects: Energy Materials; Materials Science; Polymer Chemistry; Polymer Chemistry; Energy Materials; Materials Science
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2020.101502

Easy regenerability of core components such as electrode and electrolyte is highly required in advanced electrochemical devices. This work reports a reliable, regenerable, and stretchable hydrogel electrolyte based on ionic bonds between polyacrylic acid (PAA) and polyallylamine (PAH). PAA-PAH electrolyte (1M LiCl addition) exhibits high ionic conductivity (0.050 S·cm-1) and excellent mechanical property (fracture strain of 1,688%). Notably, the electrolyte can be regenerated to any desired shape under mild conditions and remains 96% and 90% of the initial ionic conductivity after the first and second regeneration, respectively. PAA-PAH/LiCl-based supercapacitor exhibits nearly 100% capacitance retention upon rolling, stretching, and 5,000 charge-discharge cycles, whereas the regenerated device holds 97.6% capacitance of the initial device and 90.9% after 5,000 cycles. This low-cost, high-efficiency, and regenerable hydrogel electrolyte reveals very promising use in solid-state/flexible supercapacitors and possibly becomes a standard commercial hydrogel electrolyte for sustainable electrochemical energy devices. [Display omitted] •Highly reliable PAA-PAH/LiCl electrolyte for flexible supercapacitor is developed•PAA-PAH/LiCl hydrogel electrolyte can be easily regenerated under mild conditions•Regenerated hydrogel shows high retention of ionic conductivity and extensibility•Regenerated device reserves >90% capacitance and durability of the original one Energy Materials; Materials Science; Polymer Chemistry