Preparation of layered NiCo-MOF nanosheets for high-performance asymmetric supercapacitor electrode material

Metal–organic frameworks (MOFs) have become a newly developed type of potential electrode material for supercapacitors due to their special structural characteristics. Nevertheless, the inadequate electrochemical properties that characterize individual MOF structures preclude the direct application of MOFs to supercapacitors. This paper introduces a laminated stacked nanostructured NiCo-MOF electrode material based on 4,4''-ddiamino-p-terphenyl structural units, prepared using a controlled one-step solvothermal method. Owing to the three benzene rings and self-doped N atoms in the ligand, the NiCo–MOF possesses a porous and fragmented lamellar structure with numerous active sites and enhanced electrochemical properties. The synthesized layered nano-electrode material NiCo-MOF has obtained an exceptional specific capacitance of 1866 F g-1 at 1 A g-1. Additionally, despite increasing the current density resulting in 30 A g-1, an extraordinary multiplicity performance of 77.16% was achieved. More importantly, the NiCo-MOF/AC ASC assembled apparatus maintains 74.42% of its initial capacitance even after 3,000 cycles. Within a working voltage that starts at 1.55V, the assembled ASC device achieves an ultra-high energy density of 57 Wh kg-1 and an extraordinary power density of 775 W kg-1. Above MOF materials prepared from 4,4''-diamino-p-terphenyl ligands through a one-step solvothermal method are strong candidates for supercapacitor material applications.