Three-dimensional porous carbon/Co3O4 composites derived from graphene/Co-MOF for high performance supercapacitor electrodes

[Display omitted] •The nanostructured 3DPC/Co3O4 composites were prepared.•Amorphous and hierarchical structure enhanced ion and electron transport.•Oxygen-deficient Co3O4 state provided more active sites.•The 3DPC/Co3O4 delivered enhanced electrochemical performance. The three-dimensional porous carbon (3DPC)/Co3O4 composites were prepared via pyrolysis of 3D graphene/Co-MOF precursor. The rich carbon content, amorphous state and hierarchical porous structure remarkably accelerated electron and ion transport. The oxygen-deficient Co3O4 state provided more active sites. Consequently, the 3DPC/Co3O4 electrode delivered enhanced capacitive performance owing to these advantages, which exhibited a high specific capacitance of 423 F g−1 at 1 A g−1, good rate capability of 85.7% capacitance retention even at 10 A g−1, and ideal durability with about 17% capacitance decay after 2000 cycles. Moreover, the 3DPC/Co3O4//AC asymmetric supercapacitor exhibited a broad potential window of 1.7 V and a maximum energy density of 21.1 Wh kg−1 with a power density of 790 W kg−1.