Heterostructure of MnCo2O4 intercalated graphene oxide coated with Ni-V-Se nanoparticles for supercapacitors with high rate capability.

A new approach was proposed to construct a novel 3D hybrid nanocomposite heterostructure GO/MnCo 2 O 4 /Ni-V-Se as a hybrid supercapacitor electrode. Electrons can easily migrate from Mn ions to Ni ions, thereby increasing the electron energy of the metal orbital, and this inductive effect can effectively improve the electron transfer efficiency. In addition, the application of surface/interface control method also enables this electrode material to exhibit unique advantages. In this heterostructure, graphene serves as the extended conductive framework, cube-like MnCo 2 O 4 and flower-like Ni-V-Se spheres derived from MOFs as spacers separate the sheets to avoid the layer-by-layer stacking of graphene. Complemented by Ni-V-Se coating, the formed composite heterostructure exhibits excellent electrochemical performance. The as-prepared GO/MnCo 2 O 4 /Ni-V-Se delivers ultra-high specific capacity (1292.3 C·g−1 at 1 A·g−1), rate capability (94.87%) and cycling stability. Finally, the hybrid supercapacitor assembled by GO/MnCo 2 O 4 /Ni-V-Se and activated carbon also shows good electrochemical performance. [Display omitted] • Loose and porous 3D heteroconductive network had high specific capacity (1292.3 C/g) and excellent rate performance (94.87%). • A flower-like Ni-V-Se nanosphere composite derived from Ni-V-MOFs was designed for the first time. • The ternary composite avoided the stacking of graphene sheets and achieved the best synergistic effect. • GO/MnCo 2 O 4 /Ni-V-Se//AC HSC had high specific capacity, energy density and good cycling stability. [ABSTRACT FROM AUTHOR]