Oxygen plasma-etched nano-honeycomb diamond thin film electrodes were examined for electrochemical capacitor applications in non-aqueous electrolytes. As-deposited and nano-honeycomb diamond electrodes in 0.5 M TEABF4/PC both exhibited a wide potential window (approx. 7.3 V), similar to that of glassy carbon electrodes. For as-deposited diamond, the impedance behavior was found to be similar for non-aqueous and aqueous electrolytes, and the double-layer capacitance was found to be 21.8 μF cm-2, almost the same as that obtained in aqueous electrolytes. For the honeycomb diamond electrodes, however, the impedance behavior observed in non-aqueous electrolytes was significantly different from that in aqueous electrolyte and indicated that the ac signal cannot penetrate to the bottom of the honeycomb pores in the non-aqueous electrolytes due to low conductivity, and that not all the surface may contribute to the double-layer capacitance. This result was verified by mathematical simulation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Mechanical Engineering
- Materials Chemistry
- Electrical and Electronic Engineering