“Salt-in-Fiber”\nElectrolyte Enables\nHigh-Voltage Solid-State Supercapacitors

Abstract

The\ndesign of functional solid electrolytes is crucial to develop\nflexible nonsealing supercapacitors for lightweight, wearable, and\nportable electronics. Herein, an innovative method was used to fabricate\nLiCl electrospun electrolyte. A solid-state supercapacitor was assembled\nusing LiCl-containing nanofibers as both an electrolyte and separator,\nand commercial activated carbon as the positive and negative electrodes,\nrespectively. The morphology and chemical composition of the novel\nelectrolyte was revealed using scanning electron microscopy, energy-dispersive\nX-ray, Fourier transform infrared, and Brunauer–Emmett–Teller\nanalyses. The electrochemical properties of the solid-state supercapacitor\nwere characterized by cyclic voltammetry, galvanostatic charge–discharge,\nand electrochemical impedance spectroscopy techniques. Additionally,\nthe performance of the supercapacitor device with the nanofiber electrolyte\nwas compared with that of the aqueous electrolyte-based and hydrogel-based\ndevices. The supercapacitor with the LiCl nanofiber electrolyte exhibited\nan extended potential window of 2.3 V compared to 1.8 V for the aqueous-based\ndevice and 2 V for the hydrogel-based device. Consequently, the specific\ncapacitance and energy density were increased by 9.6 and 44.6%, respectively,\nwhen both devices are measured at 1 A/g.