Fabrication and characterization of single walled nanotube supercapacitor electrodes with uniform pores using electrophoretic deposition

Highlights: ► Well dispersed aqueous solutions were prepared without surfactant by functionalizing single walled carbon nanotubes. ► Carbon nanotube coated electrodes were fabricated using an electrophoretic deposition method. ► Uniform carbon nanotube nanoporous networks were suitable for supercapacitor applications. - Abstract: Well dispersed aqueous suspensions containing single walled carbon nanotubes (SWNTs) were prepared without surfactants by functionalizing SWNTs in an acid treatment. SWNT coated electrodes were prepared from the SWNT aqueous suspensions using various methods to create uniform nanoporous networks of SWNTs on stainless steel (SST) current collectors. The EPD process was identified as the primary tool for reliably producing uniform SWNT nanoporous networks on SST substrates. Optical and scanning electron microscopic images and the BET surface area analysis were used to evaluate the SWNT dispersion quality of the electrodes. The average SWNT nanopore size produced from the EPD process was found about 1 nm and was nearly unaffected by extended EPD processing times. The SWNT coated electrodes were characterized using the cyclic voltammetry and their capacitance was determined. A correlation between the extended EPD processing time and the electrode capacitance was quantified.