Morphology Control of a Nanoporous Nickel/Cobalt Double Hydroxide for Supercapacitor Electrode Materials using Halides

Nickel/cobalt double hydroxides with sphere-like nanoflowers and nanoporous structures were controllably prepared by introducing halide ions into the reaction system. The morphology and structure of the composites were characterized by X-ray diffraction, scanning electron microscope, infrared spectra and Brunauer-Emmett-Teller method. Halides, especially bromide, can dramatically affect the morphology of the crystal aggregates, and some morphology-dependent electrochemical properties are found. Nickel/cobalt double hydroxide, prepared in the presence of potassium bromide, exhibits excellent electrochemical performance. The composite's specific capacitance can reach 2630 F g(-1) at a current density of 1 A g(-1) . Even at 8 A g(-1), the composite can still retain 80.7% of its capacitance, which is much higher than that of nickel/cobalt double hydroxide prepared in the absence of bromide (68.6%).