Abstract:
We report an economical approach for the fabrication of laser-produced graphene (LPG) electrodes, which results in an improved electrochemical performance. Polyimide polymer was used as the starting material for LPG synthesis and was irradiated under ambient conditions with a CO
2 laser. The prepared LPG samples were characterized by Raman spectroscopy and FTIR, which validated the formation of multilayer graphene containing sp
2 hybridized C=C bonds. FE-SEM revealed three-dimensional (3D) sheet-like structures, while HR-TEM images showed lattice planes with an interplanar spacing of approximately 0.33 nm, corresponding to the (002) plane of graphene. Their electrochemical performance showed a remarkable areal specific capacitance (
CA) of 51 mF cm
−2 (170 F g
−1) at 1 mA cm
−2 (3.3 A g
−1) in a three-electrode configuration with 1 mol L
−1 KOH as the aqueous electrolyte. The LPG electrodes produced an energy density of ~3.5 µWh cm
−2 and a power density of ~350 µW cm
−2, demonstrating significant energy storage ability. They also had an excellent cycling stability, retaining 87% of their specific capacitance after 3 000 cycles at 1 mA/cm
2. A symmetric supercapacitor fabricated with LPG electrodes and the 1 mol L
−1 KOH electrolyte had a specific capacitance of 23 mF cm
−2 and showed excellent retention after 10 000 cycles, showing LPG’s potential for use in supercapacitors.