Fabrication of polyimide-CNTS Based Electrodes For Flexible Supercapacitor Using Laser Scribing Technique

Abstract

As there is still a research emphasis and challenge in the field of supercapacitors on how to enhance the energy density and capacitance, a great deal of work has been put forth in this study to assure good electrochemical performance of the fabricated device. Three samples were made. One sample of laser-induced graphene (LIG) had no Multi-Walled Carbon Nano-Tubes (MWCNT) coating, whilst the other two samples had MWCNT coating in varying concentrations. The reason why MWCNTs are sprayed on LIG film is to increase conductivity, stability, and flexibility as well as to enhance the electrochemical performance of the fabricated device since they are highly capacitive, flexible, and have a large surface area due to their porous nature. It is difficult to effectively pattern carbon nanoparticles in electronic and energy storage systems. We show how to induce 3D porous graphene films from polymers using a CO2 laser. The XRD analysis shows the fabricated device exhibits the structure between graphene and graphene oxide. Commercially available graphene is very expensive, and graphene is an ideal candidate for the next generation of wearable and portable devices with improved performance due to its enormous specific surface area, superior mechanical flexibility, and outstanding electrical properties. The SEM images are further taken at different resolutions to support the carbon content increasing with carbon flakes. The surface roughness of the fabricated device was also measured using atomic force microscopy, and it was found to be 2.03 µm. A rise in hump intensity is seen, which is caused by high-energy photons striking the polymer's valance atoms. This is due to the laser treatment, which causes the polymer to transform into graphitic carbon. For an optical analysis, Raman spectroscopy was performed, and the results revealed that the synthesized film has several D and G bands (1362 cm1 and 1579 cm-1 ). In the last electrochemical analysis, cyclic voltammetry analysis was carried out which shows the resulting LIG exhibits a capacitance of 6.09 mF cm-2 at a current density of 0.2mA cm-2 and an energy density of 3.38 µWh cm-2 . In comparison to the LIG produced, the LIGMWCNT coated electrode has a greater energy density of 6.05 Wh cm-2 and an areal-specific capacitance of 51.975 mFcm-2 . The fabricated device can be used in the areas of smart electronics, Nano-robotics, MEMs, and portable and wearable electronics.