Hierarchical 3D micro-nanostructures based on in situ deposited bimetallic metal-organic structures on carbon fabric for supercapacitor applications

Metal-organic frameworks (MOFs) have received considerable devotion as capable electrode materials for energy storage applications. However, applying MOFs to electrodes still faces difficulties including achieving high capacitance, rate performance with good stability. Therefore, in order to further advance the electrochemical activity, it is necessary to rationally design the electrode structure and couple the metallic elements to obtain the desired structure. Here, novel three-dimensional (3D) hollow microspheres with hierarchical structure of nickel-zinc MOFs (NZMF) are fabricated in situ on carbon fabric (NZMF/CF) by a solvo-hydrothermal approach used directly as binder-free electrode for supercapacitor applications. The rate capacity of NZMF/CF sample is higher than that of NZMF. In addition, the 3D NZMF/CF electrode offered superior specific capacitance (311.11 F g(-1)) compared with NZMF (273.33 F g(-1)), ascribed good electrical conductivity of CF scaffold. As a result, a split cell asymmetric supercapacitor device (SC-ASD) assembled using NZMF/CF//AC/CF attained a good energy density of 22.39 Wh kg(-1) at 1650 W kg(-1) power density with cyclic stability of 93.69% achieved even after 1000 cycles. This study offers a versatile scheme to efficiently prepare MOF-based binder-free energy storage materials for forthcoming hybrid and flexible electronic devices.