▎ 摘　　要

In this study, we devised an easy and simple approach to synthesize a composite of flower-like cobalt-nickel-tungsten-boron oxides (Co-Ni-W-B-O) that were doped with reduced graphene oxide (rGO); the composite was designed for supercapacitor applications. A Co-Ni-W-B alloy was first deposited on rGO through one-pot chemical reduction in an ethanol solution at room temperature. The resulting Co-Ni-W-B alloy self-oxidized in air on the rGO surface. The Co-Ni-W-B-O/rGO composites resembled three-dimensional flowers with a high surface area; they also exhibited superior electrochemical performance when compared to most previously reported electrodes based on nickel-cobalt oxides. Furthermore, the Co-Ni-W-B-O/rGO composite prepared in an ethanol solution showed much higher electrochemical performance than the composite prepared in water. The Co-Ni-W-B-O/rGO electrode showed an ultrahigh specific capacitance of 1189.1 F g(-1) at 1 A g(-1) and exhibited a high energy density of 49.9 W h kg(-1) along with remarkable cycle stability (10 000 cycles with 80.7% capacitance retention at 15 A g(-1)), which is promising for its application in energy storage devices.