To produce supercapacitor electrodes, the fct-EEM and fct-EEG supernatants were mixed at a gravimetric ratio of 1:3 and 3:1. The mixed dispersion was then ultrasonicated for 10 minutes to aid the mixing. The mixture was then filtered through PTFE membranes of a diameter of 13 mm using a syringe pump. The loading was determined by weighing the PTFE membrane before and after the filtration. The weight of the active material on the composite electrode ranged from 0.6 mg to 0.8 mg. Two identical composite membranes were then stacked back-to-back with the PTFE sides facing each other, with the PTFE membranes serving as the separator. The stacked composite membranes were then sealed in a standard CR2032 coin cell after adding 1 M H2SO4 electrolyte. This method has been demonstrated in previous papers . The pristine EEM/EEG composite electrodes and coin cells were fabricated using the same method.