A supramolecular hydrogel electrolyte for high-performance supercapacitors. (January 2021)

• Record Type: Journal Article
• Authors: Li, Guoqiang; Zhang, Xiangchen; Sang, Min; Wang, Xuan; Zuo, Danying; Xu, Jing; Zhang, Hongwei
• Is Part Of: Journal of energy storage. Volume 33(2021)
• Publication Date: 2021-01
• Subjects: Supramolecular hydrogel electrolyte -- Ionic conductivity -- Specific capacitance -- Specific energy -- Supercapacitor; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2020.101931
• Languages: English
• ISSNs: 2352-152X

Abstract

Highlights: A supramolecular hydrogel electrolyte with an ionic conductivity of 81.27 mS cm −1 is prepared. The corresponding EDLC exhibits a stable cell voltage window of 0–2 V. The corresponding EDLC delivers a specific energy of 12.6 Wh kg −1 . Abstract: With the development of flexible supercapacitors, aqueous gel polymer electrolytes with high ionic conductivity, wide voltage window, good mechanical performance and enough security are drawing great attention. Herein, a series of novel supramolecular hydrogel electrolytes are proposed and fabricated by a facile process at room temperature. They show good elongation at break and moderate ultimate tensile strength. The optimum hydrogel electrolyte exhibits an ionic conductivity of 81.27 mS cm −1, which endows a carbon-based supercapacitor with a stable voltage window of 2 V. The carbon-based supercapacitor can deliver a specific capacitance of 24.0 F g −1, a specific energy of 12.6 Wh kg −1 and a capacitance retention of 110% after 5000 charge-discharge cycles. After introducing a redox additive into the hydrogel electrolyte, the specific capacitance and specific energy of the resultant supercapacitor can be further increased to 32.7 F g −1 and 18.2 Wh kg −1, respectively. This work may provide a universal strategy to explore aqueous gel polymer electrolytes with high voltage window for applications in flexible energy storage devices. Graphical absract: A supramolecular hydrogel electrolyte for an EDLC with an electrochemical window of 2 V is studied. Image, graphical abstract