A comparative study on the performance of activated carbon electrodes and activated carbon/titanium dioxide nanotubes hybrid electrodes

Abstract

The growing need to preserve our natural resources and protect the environment has resulted in a continuous effort to develop clean, renewable, and sustainable materials for energy storage and conversion. Supercapacitors (SCs) are electrochemical storage devices that have attracted the attention of the scientific community owing to their high power density, high charge/discharge efficiency, and relatively infinite cycle-life. Recent efforts have been devoted to the development of hybrid materials for supercapacitor electrodes by combining the properties of electric double-layer (EDL) and pseudocapacitive materials to improve energy density, capacitance, rate capability, and cycle-life. In this work, the electrochemical properties of a hybrid electrode made of activated carbon (AC) and titanium dioxide nanotubes (TNT) were assessed and compared to a pristine AC electrode. The AC/TNT and the 100% AC electrodes were prepared by electrophoretic deposition (EPD) using a reticulated vitreous carbon (RVC) substrate. The electrochemical behavior of the as-prepared electrodes was analyzed by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Generally, the TNTs facilitated the EPD and enhanced the electrochemical performance of the as-prepared AC/TNT electrodes. The specific capacitances of the hybrid and pristine electrodes were 128.4 Fg−1 and 41.73 Fg−1 at 0.5 Ag−1, respectively.

Keywords

• Hybrid supercapacitors
• Activated carbon
• Titanium dioxide
• Electrophoretic deposition