Co(OH)2-combined carbon-nanotube array electrodes for high-performance micro-electrochemical capacitors

We have investigated binder-free Co(OH)2-combined carbon-nanotube (CNT) array electrodes using anodized aluminum oxide (AAO) templates for micro-electrochemical capacitors. It is shown that compared to the capacitors fabricated with CNT only electrodes (6.3 F/cm3 at 100 mV/s), those with the Co(OH)2-combined CNT array electrodes produce much higher capacitance (12.74 F/cm3 at 100 mV/s) together with superior high-rate capacitance. The improved electrochemical behavior is explained in terms of high capacitance of amorphous Co(OH)2 electrode and the use of CNT arrays as effective current collector.