Electrophoretic co‐deposition of Bi <sub>2</sub> O <sub>3</sub> –multiwalled carbon nanotubes coating as supercapacitor electrode
Daixiong Zhang, Qing Xiang
Abstract
Abstract Nafion is suggested as an efficient assistant in preparing supercapacitor by employing nanoparticles. In this work, using a bi‐additive of 0.10‐mM NaOH + 0.10 g L −1 Nafion, Nafion‐assisted electrophoretic co‐deposition of Bi 2 O 3 –multiwalled carbon nanotubes (MWCNTs) coating is successfully realized in ethanol solvent. The capacitance performances of the electrophoretic coatings in 6.0‐M KOH electrolyte are investigated by cyclic voltammetry and galvanostatic charge–discharge techniques. Comparing with Bi 2 O 3 coating prepared with electrophoretic deposition (EPD) by employing other additive (such as polyethyleneimine), the Bi 2 O 3 coating prepared by Nafion‐assisted EPD shows a better capacitance performance. Benefiting from the improvement in coating conductivity caused by MWCNTs, with a small additional amount of 4.0 wt.%, the Bi 2 O 3 –MWCNTs coating exhibits an amazing 164% increase of mass‐specific capacitance (473 F g −1 at the current density of 1.0 A g −1 ) in comparison with pure Bi 2 O 3 coating (179 F g −1 at the current density of 1.0 A g −1 ). The cyclic stability test exhibits excellent capacitance retention of 88.7% over 3000 cycles at a constant current density of 10.0 A g −1 . This work combines the advantages of MWCNTs, Nafion, and EPD to provide a facile route for preparing Bi 2 O 3 ‐based coating as a high‐performance supercapacitor electrode.