Waste carbon ashes/PEDOT:PSS nano-inks for printing of supercapacitors

The aim of this paper is the development of an innovative method for the recycling of carbon-based ashes waste derived from the production plant CMD ECO 20, designed by the company Costruzioni Motori Diesel (C.M.D.) for the combined production of electricity and heat. In this work we propose, for the first time, an original way for a technological/industrial valorisation of the carbon ashes waste, produced from biomass pyro-gasification plant, by using them as fillers of electrically conductive inks suitable for the fabrication of supercapacitors. A water-based dispersion containing nanometric waste carbon ashes (nCA), of around 300 nm, was obtained from carbon waste ashes of wooden biomass through an eco-friendly process. The developed inks based on PEDOT:PSS and nCA showed good capacity performance, explored by cyclic voltammetry (CV) measurements, with CV characterised by approximately rectangular shape and long-term stability in the time. Indeed the best specific capacitance of 26.80 ± 0.21 F/g, achieved for the nCA0.5PEDOT:PSS film was retained at 96.8% of the initial capacitance after 1000 cycles. The PEDOT:PSS/ nCA based suspensions were then characterised by rheological and surface tension analysis, as a function of the nCA concentration ahead of printing deposition with the aim to investigate the printability of the developed inks Finally, the printability of the inks was investigated and demonstrated by means of Aerosol Jet Printing (AJ®P) setup with the aim to identify a production technology suitable for their use in printed electrical applications.