Laser Direct Writing of Conductive Carbon Microelectrodes and Micro-Supercapacitor Applications

The 3D laser direct writing of a carbon microelectrode from a carbon black aqueous dispersion was developed and the carbon electrode was applied to an in-plane micro-supercapacitor (MSC). The thickness of the electrode was increased by repeating the cycle of immersion of a glass substrate into an aqueous dispersion, lifting up the substrate from the dispersion, and galvano-scanning of CO2 laser beam on the substrate covered with the carbon black aqueous dispersion. A carbonmanganese oxide (MnxOy) hybrid electrode from a carbon black-manganese (II) acetate tetrahydrate aqueous dispersion was also prepared by the 3D laser direct writing. The characteristics of in-plane MSCs composed of carbon and carbon-MnxOy hybrid electrodes were studied. A carbon-MnxOy hybrid electrode showed the characteristics of a pseudo MSC and larger capacitance than a pure carbon electrode.