Fabrication of high-rate microsupercapacitors by ultraviolet laser-assisted scribing of fluorinated graphene films

The work presents the scalable fabrication of microsupercapacitors by scribing fluorinated graphene (FG) films using a low-power ultraviolet (UV) laser. The interaction of the FG film with UV light leads to its transformation to a few-layer graphene-like material with a tunable composition and structure. In the resulting graphene/FG hybrids, the patterned graphene sections act as electrodes, while the dielectric FG areas serve as a separator/electrolyte storage. The electrochemical characteristics of the samples were studied by cyclic voltammetry, galvanostatic charge-discharge measurements and impedance spectroscopy. The best microsupercapacitors have an areal capacitance of 0.35 mF cm−2 at 0.02 V s−1, a power density of 5580 μW cm−2, and a capacity retention of 84% over the scan rate range of 0.01–1 V s−1.