A Co3O4@Ni(OH)2 core/shell nanowire arrays (NAs) material is synthesized and successfully applied to the energy storage device. Combining the performance advantages of Co3O4 nanowires and Ni(OH)2 nanosheets, Co3O4@Ni(OH)2 NAs exhibit a remarkable specific capacity (SC) of 912Cg−1 at the current density of 1Ag−1, good rate capability and cycling stability. A asymmetric supercapacitor based on Co3O4@Ni(OH)2 NAs positive electrode and active carbon (AC) negative electrode shows a broad operation voltage of 1.6V and a good specific capacitance of 140Fg−1 at 1Ag−1. All of the electrolyte used in this work is 6M KOH aqoeous solution. Furthermore, the Co3O4@Ni(OH)2//AC asymmetric supercapacitor represents prominent specific energy (49.8Whkg−1 at 801Wkg−1) and specific power (16.1kWkg−1 at 28.1Whkg−1). So, those excellent properties of Co3O4@Ni(OH)2 NAs focus more interest on similar core/shell materials.