High efficient carbon coated TiO2 electrode for ultra-capacitor applications

Abstract

The present paper reports the investigation of structural, optical, chemical bonding, and electrical properties of the carbon black (CB)/TiO2 composite synthesized via the standard sol–gel method. The structural and morphological properties have been investigated using x-ray diffraction and also field emission scanning electron microscopy to confirm the formation of the nanocomposite. The electrochemical performance of the two-electrode symmetric fabricated supercapacitor (SC) has been examined by complex impedance spectroscopy, cyclic voltammetry, and galvanostatic charge–discharge (GCD). The electrode CT15 (15% TiO2 in CB matrix) shows a high specific capacitance of 236 F g−1 at scan rate 10 mV s−1. The GCD illustrates good specific capacitance retention of 90.3% after 10 000 cycles and with energy density and power density values as 22 Wh kg−1 and 625 kW kg−1 respectively (at 1 A g−1) in the voltage window of 1.2 V. The CT15 electrode cell demonstrates superior electrochemical performance as compared to other electrodes. Electrochemical impedance spectroscopy (EIS) demonstrates the capacitive behaviour of the composite electrode with a low value of resistance. The SC cell having optimum performance has been chosen to demonstrate the glowing red light emitting diode. A mechanism has also been proposed based on received data parameters to validate the SC performance.