Three-Dimensional Co3O4 Nanowires@Amorphous Ni(OH)2 Ultrathin Nanosheets Hierarchical Structure for Electrochemical Energy Storage

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 912C g−1 at the current density of 1 A g−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 1.6 V and a good specific capacitance of 140 F g−1 at 1 A g−1. All of the electrolyte used in this work is 6 M KOH aqoeous solution. Furthermore, the Co3O4@Ni(OH)2//AC asymmetric supercapacitor represents prominent specific energy (49.8 Wh kg−1 at 801 W kg−1) and specific power (16.1 kW kg−1 at 28.1 Wh kg−1). So, those excellent properties of Co3O4@Ni(OH)2 NAs focus more interest on similar core/shell materials.