Synthesis of 2D NiCo–MOF/GO/CNTs flexible films for high-performance supercapacitors

Abstract

Flexible two-dimensional nickel–cobalt metal–organic frameworks/graphene oxide/carbon nanotubes (2D NiCo–MOF/GO/CNTs) hybrid films have been designed and prepared as high-performance supercapacitor electrode materials via vacuum filtration. The 2D NiCo–MOF nanosheets serve as the main source of capacitance for the hybrid films, while CNTs function as both the conductive network, enhancing the electrical conductivity of the MOFs, and the binder, linking the 2D NiCo–MOF nanosheets and GO. When the mass ratio of 2D NiCo–MOF, GO, and CNTs is 2 : 1 : 0.5, the hybrid film exhibits a high specific capacitance of 40.3 F g⁻¹ at 0.4 A g⁻¹. Furthermore, the film electrode demonstrates outstanding cycling stability, with a capacitance retention of 82.8% after 5000 cycles at 1 A g⁻¹. Notably, the CV curves of the asymmetric supercapacitor (ASC) show almost no change after multiple bending, indicating excellent flexibility. Additionally, two devices connected in series can light an LED, demonstrating significant potential for practical applications.