Synthesis and characterization of bimetallic metal-organic framework based on copper and iron metals (Cu-Fe MOF) as cathode electrode active materials in battery-supercapacitor (BSH) hybrid energy storage system

Achieving high power and high energy in a single storage device (such as a battery) is very challenging because high power density usually results in a trade-off for low energy density in these devices. Therefore, in this work, the design of a battery-supercapacitor hybrid storage device (BSH) is reported to achieve high power density along with high energy density [۱].Despite the different electrochemical properties and behaviors of batteries and supercapacitors, they share similar configurations, both including anode, cathode, electrolyte, separator, and current collector, which make hybridization possible [۲]. For battery and supercapacitor hybridization, we have a two-electrode cell similar to the supercapacitor system, with the difference that two asymmetric electrodes are used here. So that the anode electrode is made of carbon material with supercapacitor properties and the cathode electrode is made of metal-organic framework nanostructure (MOF) based on copper and iron metals with battery properties to have a high energy density and compensate for the low energy density of the supercapacitor.Metal-organic frameworks are considered as one of the best classes of materials for energy storage due to their impressive and unique properties such as high specific surface area, regular crystal structures, large pore volume, controllable morphology, and diverse structures [۳]. Because their porous structure is useful for the access and transportation of electrolytes, and they can provide more active sites when exposed to metal ions [۴]. In particular, a few bimetallic MOFs can be obtained when two kinds of metal ions are coordinated with ligands among the MOF structures. Therefore, in this battery-supercapacitor hybrid design, the metal-organic framework is used as the cathode electrode material. In this study, Cu-Fe bimetallic MOF (Cu-Fe MOF) is synthesized by hydrothermal method.Then, the structure of the synthesized compounds is investigated by using Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). The results show that Cu-Fe MOF is a promising cathode active material for increasing the energy density in BSH.

کلیدواژه ها:

Battery-supercapacitor hybrid ، Metal-organic frameworks ، Power density ، Energy density