Laser-Induced Formation of Fine Porous Graphitic Carbon for Eco-Friendly Supercapacitors

An electric double-layer capacitor (EDLC), which is one of the pivotal energy storage devices, provides rapid charge-discharge capabilities and an extended cycle life. Areal capacitance, a key indicator of EDLC performance, increases with the specific surface area of its electrodes. This study demonstrates a method for significantly increasing the specific surface area in the laser-induced graphitization of biodegradable polymers by incorporating NaHCO3 into the composite sheet, generating not only microscale pores but also a large number of nanoscale fine pores. Furthermore, it shows that using these structures as EDLC electrodes leads to a substantial increase in areal capacitance. An increase in the number of fine pores formed in the structure and a corresponding rise in the areal capacitance of the fabricated EDLC are observed with the increase in the NaHCO3 weight ratio. Notably, the composite sheets are composed of natural-derived, biodegradable materials, while NaHCO3 is known for its low corrosivity and biotoxicity. The proposed method thus offers a pathway for fabricating energy storage devices with minimal environmental impact, ensuring their eco-friendly disposal post-use. Fine porous graphitic carbon structures are fabricated by using NaHCO3 in laser-induced graphitization of biodegradable polymer composite sheets. Furthermore, the application of the structures to the electrodes of a supercapacitor is demonstrated. This method realizes the fabrication of energy storage devices with reduced environmental impact, both during usage and disposal in natural environments.image (c) 2024 WILEY-VCH GmbH