Supercapacitors Fabricated via Laser-Induced Carbonization of Biomass-Derived Poly (furfuryl alcohol)/Graphene Oxide Composites

The use of low-cost and widely available infrared lasers to pattern laser-induced graphene (LIG) into commercial polymers has incited intense research over the past few years due to its simplicity and ability to create various electrical and electrochemical devices. While the highest performing devices have been created by using costly synthetic polymers such as Kapton, the carbonization of one of the most common carbon precursors, the waste biomass-derived polymer poly(furfuryl alcohol) (PFA), has yet to be reported. As we demonstrate here, this is likely because PFA does not carbonize effectively via laser exposure. Instead, we show that the successful carbonization of PFA can be achieved by doping films with graphene oxide (GO) at loadings as low as 1 wt % GO. This enables the formation of highly conductive traces with sheet resistances as low as 13 Ω/sq. Supercapacitors built from microstructured PFA/GO composites result in specific areal capacitances as high as 16.0 mF/cm² at 0.05 mA/cm², which is among the highest ever reported for micro-supercapacitors based on the LIG method, and retain 97% of their capacitance over 10000 cycles. This materials system provides a simpler, more versatile, higher performing, and greener platform for laser writing than previously reported polymers and composites.