Cyclic Voltammetry Studies of Inkjet-printed NiO supercapacitors: Effect of Substrates, Printing and Materials

In the past decade the family of digital printing technology has been developed beyond the visualisation of information into a generator of a whole new set of functionalities through printed electronics, which triggered an explosion of new ideas and alternative fabrication approaches towards lean and cost-efficient manufacturing processes. Among other electronic components, inkjet-printed electrochemical systems including supercapacitors, are growing exponentially with the aim to achieve advanced form factors (i.e. flexible, stretchable, conformal, etc.) and design versatility, to simplify their production process and to lower their manufacturing cost. To the best of our knowledge, despite the growing interest in inkjet-printed electrochemical capacitors, no studies have been found to investigate the effects of printing (including substrates and materials) as a production process on the electrochemical performance and response of the devices. In this work, cyclic voltammetry studies were performed to investigate the effect of substrate and printing resolution, different types of current collector silver inks, sintering temperatures and carbon residues in electrodes, different types of electrolytes, binders and other organic compounds in electrolytes, and the effect of electrode gaps on the electrochemical response and capacitance of inkjet-printed, coplanar NiO supercapacitors. The results of this study can be extended to other electrochemical systems realised through printing fabrication processes (e.g. batteries, electrolyte-gated transistors, etc.).