Preparation and characterization of modified carbon -based electrodes for energy storage devices

Abstract

Nowadays supercapacitors have attracted great attentions as high-performance energy-storage devices. This work involves preparation of different materials such as carbon xerogels (CX), cobalt doped carbon xerogels (Co-CX), polyaniline (PANI), series of carbon xerogels with different loading of polyaniline (PANI), and cobalt doped carbon xerogels polyaniline composite (PANI/Co-CX). The characterization of the prepared samples utilizes XRD, FTIR, TEM, FE-SEM and BET of N2 adsorption/desorption isotherms techniques. These analyses verify that incorporation of PANI onto the CX and Co-CX surface reduces its specific surface area with simultaneous development of an average pore diameter from range microporous to mesoporous range. The prepared composites were tested as supercapacitors electrodes and their electro-capacitive properties were studied by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy in two-electrode cell using an acidic electrolyte of 1M H2SO4. All samples show high gravimetric capacitances ranging from 156 to 612 F∙g-1 at current density of 0.1 A∙g-1. The PANI/Co-CX exhibits higher electrochemical performance. For instance, it displays high specific capacitance of 587 F.g-1 at 0.1 A.g-1. Ragone plot delivers an energy density of 13.1 Wh.kg-1 at 68.8 W.kg-1 in the voltage range of 0 V – 0.8 V. and most stable cyclic life comprises 94% at 1 A.g-1 throughout 1500 cycles.