A Regenerable Hydrogel Electrolyte for Flexible Supercapacitors

Guanbing Zhou; Leyi Yang; Weijun Li; Chongyi Chen; Qiao Liu

doi:10.1016/j.isci.2020.101502

A Regenerable Hydrogel Electrolyte for Flexible Supercapacitors

iScience. 2020 Aug 26;23(9):101502. doi: 10.1016/j.isci.2020.101502. eCollection 2020 Sep 25.

Authors

Guanbing Zhou¹, Leyi Yang¹, Weijun Li¹, Chongyi Chen¹, Qiao Liu²

Affiliations

¹ State Key Laboratory Base of Novel Functional Materials and Preparation Science, School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China.
² Institute of Materials, Ningbo University of Technology, Ningbo 315016, China.

Abstract

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.

Keywords: Energy Materials; Materials Science; Polymer Chemistry.