Inkjet Printing-Based Micro-manufacturing of the Thin Film Electrodes for Flexible Supercapacitor Applications
Inkjet printing is one of the most promising micro-manufacturing techniques to develop thin film and flexible electronics. The selective area deposition and efficient integration of all components of an electronic device on a flexible substrate are major challenges for the existing flexible electronics field. Also, the wide spread of the portable electronics, with features such as compactness, lightweight, low cost, environment friendliness, and high-performance electronic devices, raises the demand for the more research attention in using smart manufacturing techniques to achieve the required performance of the flexible devices. Here, we have reported a micro-supercapacitor device on a filter paper substrate with ~8 μm thick electrode layer. The reduced graphene oxide (rGO) and rGO–MnO2 nanocomposite materials were converted to water-based printable inks using ethylene glycol and ethanol. The rGO ink was used to make the conducting patterns, while rGO–MnO2 nanocomposite ink is used to fabricate interdigital electrodes for the supercapacitor device. The developed device shows excellent electrochemical performance with the poly(vinyl alcohol) (PVA) 4 M KOH gel electrolyte within a voltage range of 1 V. The device shows ideal supercapacitor behavior with a highest areal capacitance of 390 mF/cm2 at one mA/cm2 current density. The developed device also exhibits excellent cycle stability with 96% capacitance retention up to 1000 cycles. Also, the excellent performance of the device in various flexibility conditions facilitates its huge potential for high-performance flexible electronics applications.
KeywordsMicro-manufacturing Inkjet printing Flexible electronics Supercapacitors
The authors would like to thank the Nanoscience unit of DST, IIT Kanpur for material characterizations, and PG Research Lab, Chemical Engineering Department, IIT Kanpur for the electrochemical analysis of the supercapacitor device. The authors would also like to thank DST for providing the research grant (DST/TMD/MES/2K17/05).