Abstract: Abstract: By doping NiOx with acetylene black (AB), the micro-structure of the composite NiOx electrode is changed and the amount of the ion channels and electron channels in the electrode is increased. As a result, the electron conduction of the NiOx is enhanced and the efficiency of the activated material's utilization is improved. Moreover, the capacitance characteristic of the composite NiOx is better. In a C/NiOx asymmetric hybrid capacitor system, the high rate capacitance of the NiOx electrode doped with 10% AB is 2.5 times as much as that of the undoped electrode. In the working voltage range, the energy density of the C/NiOx asymmetric hybrid capacitor is 1.5 times as much as that of a C/C electric double-layer capacitor.