Electrochemical Performance of Carbon Nanorods with Embedded Cobalt Metal Nanoparticles as an Electrode Material for Electrochemical Capacitors

Abstract

We describe a simple method to embed cobalt metal nanoparticles in porous carbon nanorods (Co-CNRs) as a suitable nanostructured electrode material for electrochemical capacitor (EC) applications. The Co-CNRs is synthesized by an easy and versatile electrospinning technique and followed by one step carbonization at 900 C in Ar atmosphere. Comparative studies with different cobalt loading are performed to optimize the minimum cobalt presence in different Co-CNRs to improve specific capacitance as well as life cycle. Cobalt enriched carbon nanorods with a specific surface area (SBET) of 476.1 m2g-1, pore volume of 0.3811 cm3 g -1 and pore sizes ranging from 1.18 nm to 3.78 nm are developed. Electrochemical investigations are carried out using cyclic voltammetry (CV), galvanostatic charge-discharge techniques and electrochemical impedance spectroscopy (EIS). Appreciable capacitance retention is observed, 101 Fg -1at a high scan rate of 100 mVs-1 and 108 Fg -1at a high discharge current of 5 mA. The porous Co-CNR exhibited excellent cycle stability at 50 mVs-1 for 5000 cycles in aqueous 0.5 M H2SO4 electrolyte. © 2014 Elsevier Ltd.