Anchoring Monodispersed NiSe@Ni Particles on Graphene for Energy Storage in Supercapacitors.

In this study, monodispersed NiSe@Ni particles were successfully anchored on graphene sheets by electroless nickel plating combined with a chemical-vapor-reaction process, in which the nickel particles were first deposited onto graphene sheets and subsequently transformed in situ into NiSe@Ni at an elevated temperature. The obtained product showed a unique multi-dimensional coupling structure, namely, monodispersed NiSe@Ni particles (0 D) anchored on graphene sheets (2 D), which enabled maximum synergy on the specific surface area, conductivity, and the electrochemical activity of NiSe, Ni, and graphene multi-phases. The NiSe@Ni/graphene composite showed a specific capacity of 302 mAh g⁻¹ at a current density of 1 A g⁻¹ in a potassium-hydroxide-electrolyte solution. Meanwhile, the hybrid supercapacitor of NiSe@Ni/graphene//AC exhibited a high energy density of 68.0 Wh kg⁻¹ at 803.0 W kg⁻¹ and maintained 72.53% of the initial capacity after 10,000 cycles at a current density of 10 A g⁻¹. [ABSTRACT FROM AUTHOR]