Enhanced Electrochemical Performance of Micro-Supercapacitors\nVia Laser-Scribed Cobalt/Reduced Graphene Oxide Hybrids

Abstract

The evolution of “smart life,” which connects all\ninternet-of-things (IoT) microdevices and microsensors under wireless\ncommunication grids, requires microscale energy storage devices with\nhigh power and energy density and long-term cyclability to integrate\nthem with sustainable power generators. Instead of Li-ion batteries\nwith a short lifetime, pseudocapacitors with longer or infinite cyclability\nand high-power density have been considered as efficient energy storage\ndevices for IoT. However, the design and fabrication of microscale\npseudocapacitors have difficulties in patterning microscale electrodes\nwhen loading active materials at specific points of the electrodes\nusing conventional microfabrication methods. Here, we developed a\nfacile, one-step fabrication method of micro-supercapacitors (MSCs)\nthrough the in situ formation of Co metals and the reduced graphene\noxides (rGOs) in a one-pot laser scribing process. The prepared Co/rGO\nMSC thus exhibited four times higher capacitance than the rGO MSC,\ndue to the Faradaic charge capacitance behavior of the Co/rGO composites.