Low-cost, solution processable carbon nanotube supercapacitors and their characterization

• DOI: 10.1007/s00339-014-8547-4
• Publication Date: 2014-08-19T20:46:45Z
• Authors: Suvi Lehtimäki; Sampo Tuukkanen; Juho Pörhönen; Pasi Moilanen; Jorma Virtanen; Mari Honkanen; Donald Lupo
• Keywords: 2. Zero hunger; 213 Electronic, automation and communications engineering, electronics; 216 Materials engineering; 0103 physical sciences; 02 engineering and technology; 0210 nano-technology; 7. Clean energy; 01 natural sciences

We report ecological and low-cost carbon nanotube (CNT) supercapacitors fabricated using a simple, scalable solution processing method, where the use of a highly porous and electrically conductive active material eliminates the need for a current collector. Electrodes were fabricated on a poly(ethylene terephthalate) substrate from a printable multi-wall CNT ink, where the CNTs are solubilized in water using xylan as a dispersion agent. The dispersion method facilitates a very high concentration of CNTs in the ink. Supercapacitors were assembled using a paper separator and an aqueous NaCl electrolyte and the devices were characterized with a galvanostatic discharge method defined by an industrial standard. The capacitance of the $$2\hbox { cm}^2$$ devices was $$6\hbox { mF/cm}^2$$ (2.3 F/g) and equivalent series resistance $$80\,\Omega $$ . Low-cost supercapacitors fabricated from safe and environmentally friendly materials have potential applications as energy storage devices in ubiquitous and autonomous intelligence as well as in disposable low-end products.