Electrochemical Properties of Electrochemical Capacitors Using NiO Electrode

The NiO positive electrode active material was prepared on Ni foam and Ni mesh substrates by chemical bath deposition, and a hybrid capacitor (HC) composed of the NiO-loaded Ni foam or Ni mesh positive electrode and the activated carbon fiber cloth negative electrode was assembled. Both HCs had the maximum operating voltage of 1.6 V. The HC using the Ni foam substrate with heavier weight had higher surface area, lower charge-transfer resistance and higher rate capability, while the HC using the Ni mesh with lighter weight had higher specific energy and power density. The discharge capacitance at 100 mA (700 C-rate) for the HC with the Ni foam was ca. 30 F g(-1) and was maintained even at 10(5)th cycle.