Build electrodes quickly and cheaply on a large scale with the ability to rapidly charge/discharge electrical load, and you will improve the promise of supercapacitor technology. University of Washington researchers say they have developed a scalable, rapid nanomanufacturing process to do just that.
The team applied aerogels, carbon-rich materials dried into a low-density matrix, to realize the high surface area required for an efficient electrode. The addition of graphene imbued the resulting aerogel with supercapacitor properties.
To improve capacitance and simplify the synthesis process, the aerogels were loaded with thin sheets of molybdenum disulfide or tungsten disulfide. Both materials were treated with high-frequency sound waves to break them up into thin sheets that were then incorporated into the carbon-rich gel matrix. A fully-loaded wet gel was manufactured in less than two hours; other methods would take many days.
Next, the dried, low-density aerogel was combined with adhesives and another carbon-rich material to yield an industrial 'dough' that was simply rolled out to sheets just a few thousandths of an inch thick. Half-inch discs cut from the dough were assembled into simple coin cell battery casings and tested as a supercapacitor electrode.
The devices proved fast, simple and easy to synthesize, and featured a capacitance at least 127 percent greater than the carbon-rich aerogel alone. The researchers recorded specific capacitances around 80 F/g, volumetric capacitances approaching 60 F/cm3, and low operational electrochemical impedance.