A nickel foam supported copper core/nickel oxide shell composite for supercapacitor applications

Micro porous and branched copper/nickel oxide composite with novel core shell structure was fabricated on the nickel foam by using two consecutive electroplating processes and normally used electrochemical oxidation process. Nickel foam was used as the current collector to deposit more electroactive material, and it also helped to rapidly disperse hydrogen bubbles generated during the copper electroplating process. Field emission-scanning electronic microscopy (FE-SEM) images showed that mesoporous NiO wrinkles with lateral sizes of tens of nm were well grown and dispersed on the surface of 3-dimensional copper core. The electrochemical measurements of the as prepared Ni foam/Cu/NiO composite were performed to determine its performances. A maximum specific capacitance of 416 F/g and energy density of 11.2 Wh/kg at the 3.6 kW/kg were obtained, indicating its excellent ions accessibility and charge storage ability. Moreover, the developed composite material exhibited low inner resistance (0.6 Omega) and good cycling performance along with 71.1% specific capacitance retained after 5000 cycles. These results reveal that the developed composite electrode could be a promising positive electrode candidate material for supercapacitor applications. (C) 2014 Elsevier Inc. All rights reserved.