Supercapacitive Performance of N-Doped Graphene/Mn3O4/Fe3O4 as an Electrode Material

Abstract

Nitrogen-doped graphene (NDG) and mixed metal oxides have been attracting much attention as the combination of these materials resulted in enhanced electrochemical properties. In this study, a composite of nitrogen-doped graphene/manganese oxide/iron oxide (NDG/Mn3O4/Fe3O4) for a supercapacitor was prepared through the hydrothermal method, followed by freeze-drying. Field emission scanning electron microscopy (FESEM) images revealed that the NDG/Mn3O4/Fe3O4 composite displayed wrinkled-like sheets morphology with Mn3O4 and Fe3O4 particles attached on the surface of NDG. The presence of NDG, Mn3O4, and Fe3O4 was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The electrochemical studies revealed that the NDG/Mn3O4/Fe3O4 composite exhibited the highest specific capacitance (158.46 F/g) compared to NDG/Fe3O4 (130.41 F/g), NDG/Mn3O4 (147.55 F/g), and NDG (74.35 F/g) in 1 M Na2SO4 at a scan rate of 50 mV/s due to the synergistic effect between bimetallic oxides, which provide richer redox reaction and high conductivity. The galvanostatic charge discharge (GCD) result demonstrated that, at a current density of 0.5 A/g, the discharging time of NDG/Mn3O4/Fe3O4 is the longest compared to NDG/Mn3O4 and NDG/Fe3O4, indicating that it had the largest charge storage capacity. NDG/Mn3O4/Fe3O4 also exhibited the smallest resistance of charge transfer (Rct) value (1.35 Ω), showing its excellent charge transfer behavior at the interface region and good cyclic stability by manifesting a capacity retention of 100.4%, even after 5000 cycles.

Influence of Temperature on ZnO/Co3O4 Nanocomposites for High Energy Storage Supercapacitors

“…In the low-frequency region, ZnO/Co 3 O 4 @450 exhibited a more inclined line than the others. This suggests that the intricate structure of ZnO/Co 3 O 4 @450 limited ion diffusion compared to the rapid ion adsorption/desorption on its large surface. , …”

“…This suggests that the intricate structure of ZnO/Co 3 O 4 @450 limited ion diffusion compared to the rapid ion adsorption/desorption on its large surface. 69,70 Thus, the ZnO/Co 3 O 4 @450 nanocomposite deposited by the two-step CBD method was found to be a promising material for pseudocapacitors, and the importance of calcination temperature to develop crystalline structures was confirmed.…”

A simple strategy to prepare a layer-by-layer assembled composite of Ni–Co LDHs on polypyrrole/rGO for a high specific capacitance supercapacitor

“…The initial enhancement in the retention can be ascribed to the self-activation process where the electrolyte gradually penetrating into the active material, resulting in the activation of redox species of the active materials. 42 With the further increase in the number of cycles, the capacitance retention gradually decays to 89% of its initial capacitance after 5000 cycles. The major drawback of LDHs based electrodes is poor stability due to structural instability of LDHs during the continuous charge–discharge cycling process.…”

Improved Electrochemical Performance of Ni2P2O7 and Mn‐doped Ni2P2O7 Electrode Materials for Supercapacitor Applications

“…[4] As the electrochemical performance of SCs mainly depends on the nature of electrodes, novel materials for electrode fabrication remain prerequisite to achieve the same. Carbon enriched material such as activated carbon, [5] graphene [6] and its hybrid composites [7] are widely utilized as active electrode material for EDLCs because of their fascinating properties such as high surface area, controlled porosity and high ionic conductivity. PCs are based on oxide materials like NiO, [8] Co 3 O 4 /Co(OH) 2 , [9] MnO 2 , [10] RuO 2 [11] etc., and conducting polymers like polyaniline, [12] polypyrrole [13] polythiophene [14] etc., are used as electrode materials because they have high electrochemical activity which leads to high specific capacitance.…”