Abstract
The next generation of energy storage technologies requires enhanced fabrication techniques such as the use of CO2 infrared lasers to pattern micro-supercapacitor (MSC) electrodoes. This study reports direct-writen laser-induced graphene (LIG) micro-supercapacitors with electrodepositated NiCo2S4-nanoparticles on commercial polyimide sheets. X-ray photoelectron spectroscopy (XPS) combined with transmission electron microscopy (TEM) showed NiCo2S4 nanoparticles decorating the graphene, within a highly porous carbon-based electrode. The LIG/NiCo2S4 exhibited outstanding properties with a specific capacitance of 30.4 mF cm-2 at 0.75 mA cm-2 and an energy density of 16.9 µWh cm-2 at a power density of 367.5 µW cm-2. High capacitance retention of 1.22-fold was measured after 5000 cycles of charge/discharge, and of ~90% when bent to 120ångle. Here, it is demonstrated that surface decoration is an effective route in improving LIG MSC storage properties, and that the LIG/NiCo2S4 MSC is suitable for use in next generation of flexible and miniaturized portable devices.