Electrochemical properties of the HFG-based quasi-solid-state supercapacitor. (a) Schematic structure, (b) CV curves, and (c) areal capacitances of the HGF-based asymmetric supercapacitor. Inset in (c) is the EIS results. Ragone plots of aqueous and quasi-solid-state asymmetric supercapacitor based on (d) area, (e) volume, and (f) active material mass of the whole device. (g) Comparison of the CV curves of the asymmetric supercapacitor in its initial state and under compression. (h) Photographs of LEDs powered by two HGF-based supercapacitors in the initial state and under compression. (i) Cycling performance of the HGF-based asymmetric supercapacitor.