Templated synthesis of spinel cobaltite MCo2O4 (M=Ni, Co and Mn) hierarchical nanofibers for high performance supercapacitors

Abstract

Rational construction of transitional metal oxides electrode materials with suitable structure and composition is an effective strategy of improving their electrochemical performance. Herein, novel MCo2O4 hierarchical nanofibers (H-MCo2O4NFs, M = Ni, Co and Mn) were fabricated by a multi-step self-templating method using electrospun nanofibers as precursors. Benefiting from the unique structure, such as numerous of vertically interlinked nanosheets on the surface and 1D interwoven nanofibers networks, the obtained HNiCo2O4NFs electrode exhibits a high specific capacitance of 1750 F g−1 (At a current density of 0.5 A g−1), good rate capability (Capacitance retention of 70% at 20 A g−1), and outstanding cycling stability (Capacitance retention of 92% after 6000 cycles). Moreover, the solid-state hybrid supercapacitor assembled by HNiCo2O4NFs and activated carbon (AC), delivers a high energy density of 38.4 Wh kg−1 at a power density of 800 W kg−1, and excellent cycling stability. Thus, the HNiCo2O4NFs is a promising candidate material for supercapacitors electrode and this self-templating method in this work also provides a new path for the preparation of one-dimensional hierarchical metallic oxides.

Keywords

• Electrospinning
• Supercapacitor
• NiCo2O4
• Hierarchical nanofibers
• Self-templating method