Porosity-engineered Hard Carbons Hybridized with Carbon Nanotubes for Electrochemical Capacitors

Abstract

Mesoporous carbon-based materials are attractive for energy storage devices. A novel multidimensional carbonaceous electrode material (hard carbon-CNT, denoted as HC-CNT) with the utilization of porous hard carbon as support was successfully synthesized in this work. Morphology of as-obtained products was characterized by scanning electron microscopy (SEM), the phase was investigated by X-ray diffraction (XRD), and the surface area was tested via Brunauer Emmett Teller (BET) method. The specific area of as-synthesized HC-CNT was up to 72.1 m(2)/g compared to hard carbon material (2.4 m(2)/g). The electrochemical characterization of HC-CNT electrode was performed in a three-electrode system. The results indicated great improvement in electrochemical performances for supercapacitors. The mass-specific capacitance of HC-CNT was 96.6 mF/cm(2) at the current density of 1.5 mA/cm(2), which was approximately two to three times larger than that of HCs. Furthermore, HC-CNT electrode showed a lower internal resistance and superior charge-discharge property, demonstrating the kind of materials can be a promising candidate for electrode material for energy storage devices.