Abstract
Nano‐sized NiO/Ni composite films have been found to perform as superior electrodes in electrochemical capacitor applications. These films can provide a specific capacitance of 50 to 64 F/g. The specific energy and specific power of these films were 25 to 40 kJ/kg and 4 to 17 kW/kg, respectively. These specific quantities are dependent on the microstructure of the films. Superior performance can be obtained from samples having rough surfaces and consisting of larger secondary particles (ca. 100 to 120 nm in diam).