Enhanced asymmetric supercapacitor performance via facile construction of Cu-MOF@Co(OH)2 heterostructure

Integrating metal-organic frameworks (MOFs) with transition hydroxides has the potential to enhance the inadequate electronic conductivity and address the slow diffusion of MOF materials in electrochemical applications. Herein, we synthesized a 2D Cu-MOF and successfully prepared a Cu-MOF@Co(OH)2 heterostructure using a one-step hydrothermal method on a Co(OH)2/NF (nickel foam) substrate. The hybrid Cu-MOF@Co(OH)2 material exhibits high electrochemical reactivity, resulting in enhanced pseudocapacitor performance, with a specific capacitance of 2039.8 mF cm-2 at a current density of 1.0 mA cm-2. In addition, an asymmetric twoelectrode cell was constructed using Cu-MOF@Co(OH)2/NF and activated carbon (AC)/NF, exhibiting a specific capacitance of 444.5 mF cm-2 at a current density of 1.0 mA cm-2, and demonstrating decent cycling durability with 90.1 % retention after 2000 cycles.