Co-electrodeposition of NiCu(OH)2@Ni-Cu-Se hierarchical nanoparticle structure for supercapacitor application with enhanced performance

Currently, a hierarchical nanostructure with a new atom inserting into active material has paid more attention to the supercapacitor application. Here, we present a vertical growth of NiCu(OH)(2) wrapped Ni-Cu-Se co-axial nanoparticle structure via the co-electrodeposition technique. The deposition of NiCu(OH)(2) on top of Ni-Cu-Se can exhibit excellent electrochemical performance. As a result, the NiCu(OH)(2)@Ni-Cu-Se offers a high specific capacitance 264.91 F g(-1 )and capacity of (158.95 mAh g(-1)) at a current density of 1 A g(-1), which is significantly higher than that of Ni-Cu-O and Ni-Cu-Se. Moreover, the electrode delivers good long-term cycling stability of 3000 cycles (the capacitance decreased to 24.2% of its initial capacitance value). The improved performance mainly attributed to the synergetic effect of NiCu(OH)(2)@Ni-Cu-Se, and its unique hierarchical nanostructure plays a vital role in providing rich redox reactions, high conductivity, efficient charge transport and short ion diffusion. This study opens a new platform for layered bimetallic hydroxide into selenium as promising active electrode material for energy storage devices.