One‐Step Controllable Synthesis of Mesoporous MgCo₂O₄ Nanosheet Arrays with Ethanol on Nickel Foam as an Advanced Electrode Material for High‐Performance Supercapacitors

Abstract

In recent years, ternary transition metal oxides (TTMOs), especially spinel type TTMOs have attracted widespread attention as promising candidates for electrode materials. Among all of the popular TTMOs, MgCo O is an outstanding one, owing to its superior theoretical capacitance. In this work, MgCo O nanosheet arrays (NSAs) grown directly on nickel foams were fabricated through a facile hydrothermal process at 120 °C for 4 h. With a series of structural and morphological characterization techniques, it was found that the ethanol played a key role in controlling the composition and morphology during the synthesis process. The MgCo O NSAs exhibited a superior specific capacitance of 853.06 C g (at 1 mA cm ) and enhanced cycling performance, with 94.65 % of initial capacitance retained after 3000 cycles when used as a binder-free integrated electrode for electrochemical supercapacitors; much higher than other reported data for MgCo O as well. The excellent electrochemical properties mainly came from the unique morphology of the MgCo O NSAs. This study will demonstrate the applications of MgCo O NSAs based large-scale supercapacitors grown on low-cost nickel foams.

Fluoride ion assisted growth of hierarchical flowerlike nanostructures of Co/Ni ferrites and their magnetoresistive response

“…The solution in autoclave was treated at 120 C for 4 h while another, similar solution was treated at 180 C for 4 h. This optimization was done in accordance with the different literature available for the synthesis of these NSs using the hydrothermal technique. 22,23 These as-synthesized NSs were then taken out in the form of the powder and repeatedly washed with deionized water. Finally, the powder was heat treated at 300 C for 2 h. The CoFe 2 O 4 NRs thus produced which were heat treated at 120 C were named as CFO-1, while the sample heat treated at 180 C was named CFO-2.…”

“…This method has been previously adopted to synthesize nanosheet arrays of MgCo 2 O 4 using hydrothermal approach. 22 Hydrothermal method is one of the most facile chemicals method to synthesize NSs but generating arrays of NSs is not a simple task. Here, a small amount of an active reagent ammonium uoride is used for the self-assembly of these NR arrays to form ordered owerlike pattern.…”

Investigating the Influence of Reflux Condensation Reaction Temperature on the Growth of FeCo2O4 Thin Film for Flexible Supercapacitor

“…The size and shape of complex spinel structure binary transition metal oxide material play a very important role in electrochemical performance because of their physical and chemical properties [21] . Spinel's like NiFe 2 O 4 , [22–23] CuCo 2 O 4 , [24–25] MgCo 2 O 4 , [26–27] ZnCo 2 O 4 , [28–29] NiCo 2 O 4 , [30–31] ZnMn 2 O 4 , [32–33] MnCo 2 O 4 , [34–35] and CoMn 2 O 4 [36–37] with different nanostructures are promising low cost and eco‐friendly alternative supercapacitor electrodes demonstrating excellent electrochemical performances. Binary metal oxides exhibit a synergistic effect with the contribution from the participating metal ions thereby improving the conductivity, capacitive performance, stability, and expanding potential window [38–40] .…”

Facile hydrothermal synthesis of porous MgCo2O4 nanoflakes as an electrode material for high-performance asymmetric supercapacitors

“…In general, PCs can deliver higher specic capacitance and energy density than EDLCs. [12][13][14][15] Among the various electrode materials for PCs, transition metal oxides (TMOs) such as NiO, MnO 2 and Co 3 O 4 are considered as the most promising candidates owing to their high theoretical specic capacitance. 16 Co 3 O 4 can provide relatively huge capacitance owing to its rich redox reactions.…”