Facile syntheses and electrochemical properties of Ni(OH)2 nanosheets/porous Ni foam for supercapacitor application

We demonstrated a novel porous Ni foam (PNF) with small voids/pores penetrating the skeleton wall by a simple etching process using commercial Ni foam, aiming to achieve the maximum use of its hollow structure for various nanostructured materials growing as the electrode for supercapacitor application. The hydrothermal Ni(OH)2 nanosheets, functioning as the battery-type active material, were successfully grown vertically on both inner and outer surface of the PNF skeleton. The Ni(OH)2/PNF electrodes exhibited high capacity of ∼578 C/g at 1 A/g current density with capacitance retention of ∼90% after 3000 cycles, which was much higher than those of the Ni(OH)2/NF electrodes. The strategy suggests that 3D PNF not only provides a universal route for the rational design of biface (inner and outer) growth of various nanostructured electrode materials, but also reducing the total mass of the electrode supporter by take full advantage of the hollow structure of Ni foam for the industrial applications.