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

The evolution of smart life, which connects all internet-of-things (IoT) microdevices and microsensors under wireless communication grids, requires microscale energy storage devices with high power and energy density and long-term cyclability to integrate them with sustainable power generators. Instead of Li-ion batteries with a short lifetime, pseudocapacitors with longer or infinite cyclability and high-power density have been considered as efficient energy storage devices for IoT. However, the design and fabrication of microscale pseudocapacitors have difficulties in patterning microscale electrodes when loading active materials at specific points of the electrodes using conventional microfabrication methods. Here, we developed a facile, one-step fabrication method of micro-supercapacitors (MSCs) through the in situ formation of Co metals and the reduced graphene oxides (rGOs) in a one-pot laser scribing process. The prepared Co/rGO MSC thus exhibited four times higher capacitance than the rGO MSC, due to the Faradaic charge capacitance behavior of the Co/rGO composites.

Automated summary

The evolution of smart life requires microscale energy storage devices with high power and energy density to integrate IoT devices with sustainable power generators. Pseudocapacitors are considered efficient energy storage devices due to their longer cyclability and high-power density compared to Li-ion batteries, but there are difficulties in patterning microscale electrodes using conventional methods. A one-step fabrication method of micro-supercapacitors was developed through the in situ formation of Co metals and reduced graphene oxides in a one-pot laser scribing process, resulting in a Co/rGO MSC with four times higher capacitance than rGO MSC.