Sustainable Laser Induced Supercapacitors from Cork Natural Substrates

Abstract

A novel type of eco-friendly and cost-effective supercapacitor has been developed by fabricating interdigitated and squared supercapacitors made of porous graphitic carbon electrodes and Polyvinyl alcohol (PVA) electrolyte. The electrodes were fabricated using a simple, fast, and low-cost laser engraving process, using visible irradiation wavelengths (450 nm) and performed under ambient conditions, resulting in highly three-dimensional, electrically conductive, and porous graphitic carbon structures.By adjusting the laser power and wavelength, it was possible to produce electrode materials with highly porous and high surface area morphology, which are promising for electrochemical applications. Spectral investigation using Raman and FTIR spectroscopies confirmed the formation of graphitic carbon structures and the full conversion of the cork precursor under visible laser irradiation.The obtained electrodes exhibited excellent supercapacitive behavior when exposed to a PVA electrolyte, achieving a specific areal capacitance of up to 11.24 mF/cm2 with PVA at 30% laser power. The supercapacitive properties showed excellent stability over time, with no significant loss after 10000 charge/discharge cycles.To evaluate the performance of the new supercapacitors, linear electrodes were used as working electrodes in a three-electrode configuration electrochemical cell. The electrodes showed diffusion-limited electrochemical behavior with fast heterogeneous electron transfer rates (HET), which was superior to that of traditional glassy carbon electrodes.The innovative and efficient electrode fabrication method presented in this study, which utilizes low-cost instrumentation, environmentally friendly fabrication methods, and Earth-abundant precursor materials, shows great promise for producing large-scale "green" electrochemical sensing platforms and devices in the future.