Scalable fabrication of flexible supercapacitor electrodes using sustainable water‐based onion‐like carbon inks

Abstract

The increasing usage of electrical energy storage solutions demands for cost effective, scalable and sustainable manufacturing technologies. Deposition of functional inks, carrying electrochemically active materials is a suitable technique as it delivers material with selected properties only to required locations. However, the production of stable dispersions featuring high concentrations of active material ‐ necessary for effective deposition ‐ is challenging. Here we present an approach to print supercapacitor electrodes with onion‐like carbon as active material, using a simple, cost‐effective process as well as a water‐based ink. The ink is highly stable and can be deposited by spray and inkjet techniques. The fabricated electrodes offer a capacitance of up to 14 mF cm -2 (27 F g -1 ) and retained 97 % of their initial capacitance after 5000 cycles, demonstrating excellent performance and stability of the coating.