Laser‐induced graphene‐based flexible interdigital electrode realizing micro supercapacitor sustainable in different temperatures

Abstract

Abstract Electronic components for energy storage need to be mechanically conformable to ensure maximum wearer comfort, flexibility, and good thermal stability in different environments. Hence, the development of supercapacitors (SCs) as an alternative to micro‐batteries for use in microelectronics applications is currently receiving much scientific attention. This work presents an adaptable, cost‐effective, and efficient method to fabricate flexible laser‐induced graphene (LIG) supercapacitor electrodes using a CO 2 laser. LIG formation and morphology have been studied and confirmed through energy dispersive X‐ray (EDX) spectroscopy and scanning electron microscopy (SEM) techniques. The interdigital laser‐induced graphene electrodes are fabricated and optimized for SCs on a flexible substrate. These SCs have the advantages of charge‐discharge cycles, capacitive performance, high power density as well as long cyclic life. For LIG electrodes, the suitable electrolyte is optimized to control the electrochemical properties of supercapacitors, such as charge transfer, flexibility, and stability. Hence, a supercapacitor composed of 3D porous laser‐induced graphene with PVA‐KOH gel electrolyte is fabricated, with 83.33 mF/cm 2 areal capacitance at a constant current density of 0.5 mA/cm 2 . The energy density 4.62 μWh/cm 2 and power density 0.2 mW/cm 2 are observed at a 0.5 mA/cm 2 constant current density. The capacitance of the proposed SC increases with an increase in certain temperatures and shows excellent performance. This flexible SC could be a high potential for use in energy storage and wearable device applications.