Flexible Supercapacitor Device Based on Laser-Synthesized Nanographene for Low-Power Applications

Laser-induced graphene (LIG) and laser-induced reduced graphene oxide (LIrGO) are two relatively recent graphene-based nanoscale materials suitable for miniaturized flexible supercapacitors. This study employs direct laser engraving techniques to generate patterns on flexible substrates, such as paper and polyamide (PI). This methodology allows fine control over the formed nanographene structures to fabricated LIG and LIrGO supercapacitors. The LIG on PI exhibits a distinctive porous structure and high surface area, adsorption, and transportation of ions. Furthermore, paper-based LIrGO electrodes are recyclable and are formed in a single step. The morphological study is done using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Galvanostatic charge–discharge studies at 0.05 mA cm⁻² current density show an areal capacitance of 3.69 mF cm⁻² for LIG and 1.61 mF cm⁻² for LIrGO. The comparable energy densities for LIG and LIrGO are 0.32 and 0.16 μWh cm⁻², respectively. From the calculative analysis of both types, the variation in specific areal capacitance enabling effective is 56.3% from GCD, indicating that the LIG device performs better. Finally, a portable potentiostat is employed to investigate the viability of utilizing supercapacitors to operate self-powered sensors in a portable and integrable fashion.