Desenvolvimento de microsupercapacitores de grafeno induzido por laser recobertos com sulfeto de níquel cobalto pelo método de eletrodeposição

Abstract

The continuous increase in the demand for new energy storage technologies has driven numerous studies in the field of microelectronics. More recently, the use of infrared laser to produce patterned electrodes for microsupercapacitors has been extensively studied. This study reports a method of Ni-C-S coated laser induced graphene microsupercapacitors (MSCs) by combining the synthesis of laser-induced graphene (LIG) through direct laser writing on commercial polyimide sheets and posterior electrodeposition of Ni-Co-S. XPS and FESEM analysis were performed and revealed the existence of a highly porous structure containing Ni-Co-S homogeneously distributed along the entire substrate. As a result, the LIG/Ni-Co-S MSC exhibited excellent electrochemical properties, with the highest specific capacitance of 30.4 mF.cm-2 at 0.75 mA.cm-2 and an energy density of 32.25 µWh.cm-2 (16.9 Wh.kg-1 ) at a power density of 1210 µW.cm-2 (367.5 W.kg-1). These values are much higher than bare LIG MSC and are among the best for LIG-based MSCs. Furthermore, high capacitance retention of 122% was obtained after 5000 cycles, showing to be a promising candidate for the next generation of miniaturized portable devices.