Amorphous FeOOH nanorods and Co3O4 nanoflakes as binder-free electrodes for high-performance all-solid-state asymmetric supercapacitors.

We have built a high-performance supercapacitor anode based on carbon fabric (CF), vertically aligned graphene nanosheets (VAGN) and FeOOH nanorods. This CF/VAGN/FeOOH electrode can charge/discharge at a low potential window (0 to −1.1 V vs. Hg/HgO), and demonstrates a high specific capacitance of 909 F g−1 aided by the unique structure of VAGN. Additionally, we made an all-solid-state asymmetric supercapacitor by assembling CF/VAGN/FeOOH and CF/Co3O4 electrodes. The asymmetric design broadens the working potential up to 1.7 V, leading to a high energy density of 33 W h kg−1 and a high power density of 26 kW kg−1. We believe that the CF/VAGN/FeOOH electrode holds great promise for applications in high-performance asymmetric supercapacitors. [ABSTRACT FROM AUTHOR]