Co₃O₄/MoCo/Layered Double Hydroxide Nanosheets for Asymmetric Supercapacitor

Abstract

Recent research studies have focused on energy storage systems such as supercapacitors with high power density, good operational safety, and durable cycling life. Hence, the structure design effectively promotes the excellent performance of pseudocapacitive materials as an electrode in a supercapacitor. In this research, Co 3 O 4 /MoCo/LDH is prepared and fabricated as a binder-free electrode on the nickel foam. The Co 3 O 4 nanowires (NWs) and MoCo layered double hydroxides (LDHs) are synthesized via a hydrothermal pathway with a combination of calcination processes and characterized by various techniques, including attenuated total reflectance-infrared (ATR-IR), field emission-scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) patterns. This electrode enlarges active sites and enhances the rates of ion/electron diffusion. As a result, the Co 3 O 4 /MoCo/LDH/NF electrode demonstrates a superb specific capacitance of 2677 F g −1 at 1.0 A g −1 , great cycling stability after 5000 cycles (maintaining 93.2% of its initial capacitance) at 9.0 A g −1 , and an excellent capacity retention rate of 62.86% at 15 A g −1 , which shows better performance than MoCo LDH/NF and Co 3 O 4 NWs/NF electrodes. Furthermore, an asymmetric supercapacitor is fabricated by Co 3 O 4 /MoCo/LDH and activated carbon; Co 3 O 4 /MoCo/LDH/NF//AC ASC exhibits a specific capacitance of 190.2 F g −1 at 1.0 A g −1 and an outstanding energy density of 67.62 Wh kg −1 at a high power density of 800 W kg −1 . Therefore, it is a promising electrode for energy storage applications.

Three-Dimensional Lanthanide-Based Nanoporous Metal–Organic Frameworks for High-Performance Supercapacitors

“…While at higher current densities, the movements of OH – ions are very fast so there is insufficient time for ions to reach the inner active sites of the electrode material and therefore faradaic reactions are not that prominent. This is the general phenomenon usually observed in the battery type supercapacitive materials. ,,, …”

“…The diffusion controlled or capacitive (surface) process are represented by the following equations: − i = a v b log ( i ) = b log ( ν ) + log ( a ) where, i = peak current density, ν = sweep rate, a and b are constants. The value of b can be obtained from log ( i ) versus log (ν) plot.…”

Sustainable Furfural Biomass Feedstocks Electrooxidation toward Value‐Added Furoic Acid with Energy‐Saving H2 Fuel Production Using Pt‐Decorated Co3O4 Nanospheres

“…00–042‐1467 of cubic Co 3 O 4 . [ 31,32 ] In addition, the Pt‐Co 3 O 4 sample exhibited a faint peak of cubic Pt NPs at 39.9°, corresponding to the most prominent (111) crystal plane according to the JCPDS card no. 70‐2057.…”

Recent Progress in Co3O4‐Based Nanomaterials for Supercapacitors

“…The obtained Co 3 O 4 /MoCo‐LDH exhibited a high specific capacitance of 2677 F/g at the current density of 1.0 A/g, which was significant for the original MoCo‐LDH and Co 3 O 4 components. In addition, at 9.0 A/g current density, the electrode showed an initial capacitance of 93.2% after 5000 cycles, showing lasting cyclic stability [111] . Zhang et al.…”

“…In addition, at 9.0 A/g current density, the electrode showed an initial capacitance of 93.2% after 5000 cycles, showing lasting cyclic stability. [111] Zhang et al made use of the high oxidation and reduction of layered double hydroxides (LDHs) and the synergistic effect of each component to prepare heteronuclear shell structure Co 3 O 4 @NiAl-LDH (Co 3 O 4 @LDH)materials have been proved to be crucial to improve the electroactive sites and charge transfer dynamics of high-performance SCs. Also by hydrothermal methods, onedimensional Co 3 O 4 nanowire arrays (NWAs) were directly grown on NF as the "core" and NiAl-LDH nanosheets (NSs) as the "shell" to obtain three-dimensional layered Co 3 O 4 @LDH coreshell network structures (NWs).…”