One−Step Synthesis of Fe−Based Metal–Organic Framework (MOF) Nanosheet Array as Efficient Cathode for Hybrid Supercapacitors

Abstract

With the flourishing development of the new energy automobile industry, developing novel electrode materials to balance the capacity between cathode and anode is a challenge for hybrid supercapacitors. In comparison to conventional inorganic materials, metal–organic frameworks materials offer higher porosity and greater surface area for use in supercapacitors. Herein, we proposed a facile one–pot solvothermal technique to synthesize an Fe(BPDC) nanosheet array on Ni foam, which we then applied as a binder–free cathode for a supercapacitor. The solvothermal time was adjusted to ensure a desirable morphology of the final product. Benefitting from the impressive nanosheet morphology, to a great extent, Fe(BPDC) has solved the problem of volume expansion of Fe–based electrode materials during cycling, and exhibits brilliant electrochemical performances, i.e., high specific capacitance (17.54 F/cm2 at 1 mV/s) and satisfactory cycle performance (129% retention after 10,000 cycles). Furthermore, Fe(BPDC) and activated carbon (AC) have been chosen to assemble a hybrid supercapacitor (namely Fe(BPDC)//AC), delivering an energy density of 45.64 Wh/kg at the power density of 4919.6 W/kg with 87.05% capacitance retention after 10,000 cycles. These brilliant results prove that Fe(BPDC) material has great potential as the cathode of supercapacitors.