Ru_xBi_1‐x‐oxide as an electrode material for pseudocapacitors

Abstract

The influence of RuxBi1‐x‐oxide composition on the materials' charge storage/delivery capabilities as potential supercapacitor electrode materials was investigated in an alkaline medium. The oxides were produced as 2D coatings on a Ti substrate and were characterized by employing cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy, and scanning electron microscopy techniques. It was found that with an increase in Ru content in the binary oxide, the corresponding specific areal capacitance increased, reaching a maximum value of 338 ± 4 mF/cm2 at the current density of 3 mA/cm2 for the Ru0.6Bi0.4‐oxide composition, and then decreased with a further increase in Ru content. Ru0.6Bi0.4‐oxide was found to retain ~72% of its initial charge storage capacity after 5000 charging/discharging cycles at a high current density (200 mA/cm2). These results indicate that Ru0.6Bi0.4‐oxide exhibits excellent charge storage/delivery capabilities and could be a potential candidate for nanostructured electrode materials for supercapacitors.

Plasma-functionalized multi-walled carbon nanotubes directly grown on stainless steel meshes as supercapacitor electrodes

“…Unlike pure electrical double-layer capacitors that show a vertical line, the frequency dependence of the real impedance component reveals the pseudo-capacitive properties and/or the existence of impedance resulting from the porosity of all three electrodes. A slightly sloped and curved line in the lower frequency region and a semicircle-like behavior in the higher frequency region (figure 6(b)) originate from the kinetics of the redox reaction and ion movement inside the pores, contributing to the actual impedance component, thus yielding two time constants [41].…”

Dual‐template synthesis of hierarchical porous carbon and its application in electrical double‐layer capacitors

“…[4,5] Generally, supercapacitors are basically divided into two categories based on the mechanism of energy storage: electrical double-layer capacitors (EDLCs) and pseudocapacitors (PCs). [6,7] EDLCs are more popular than PCs in commercial applications because of their high power density. The electrode material is considered the key component of the EDLCs, which determines the ultimate electrochemical performance, such as specific capacitance and power density.…”