Thick, Binder-Free Carbon-Nanotube-Based Electrodes for High Power Applications

Abstract

In this study, synthesis and characterization of thick carbon nanotube (CNT) electrodes with impressive electrical conductivity, mechanical properties, and large surface area is presented. The electrodes are made by effectively cross-linking the CNTs with graphitic carbon particles. The random network of cross-linked CNTs results in a bulk conductivity of >60 S/cm, large Young's modulus (∼1.2 GPa), and high surface area (>500 m2/g). Electrochemical characterization of these thick CNT electrodes (100–1000 μm) shows a capacitance of 90 F/g (40 F/cm3) in an aqueous electrolyte (5 M KOH). Furthermore, much of this capacitance is maintained at fast scan rates up to 1000 mV/s. This high rate performance leads to a simultaneous display of large energy densities (>10 Wh/kg) and power densities (>40 kW/kg) for the thick, binderless CNT electrode.