High voltage and self-healing zwitterionic double-network hydrogels as electrolyte for zinc-ion hybrid supercapacitor/battery

The hydrogel electrolyte is an important part of safety and development potential in zinc -based energy storage equipment due to its inherent low mechanical strength and voltage decomposition. However, hydrogel electrolytes possess a reduced working life for zinc dendrites growth and a narrow voltage window. In this study, a hydrogel electrolyte pre-pares by the zwitterionic monomer [2-(methacryloyloxy) ethyl]dimethyl-(3-sulfopropyl) (MS) and sodium alginate (SA) alleviate these problems. The zwitterionic double-network hydrogel has good mechanical strength, inhibits the growth of zinc dendrites, enhances practicability, greatly increases the voltage window (0-2.4 V), and has self-healing prop-erties to its rich functional groups. The assembled zinc-ion hybrid supercapacitors (ZHSs) have a high-power density of 172.33 W kg(-1) and an energy density of 88.56 Wh.kg(-1) at 0.5 A g(-1). The assembled zinc-ion battery also has good electrochemical performance. Flexible ZHSs and batteries provide power to the timer stably under different bending angles. The zwitterionic double-network hydrogel can be applied to both zinc-based supercapacitors and batteries. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.