Two-Dimensional Core-Shell Structure of Cobalt-Doped@MnO2 Nanosheets Grown on Nickel Foam as a Binder-Free Battery-Type Electrode for Supercapacitor Application

Abstract

Herein, we present an interfacial engineering strategy to construct an efficient hydrothermal approach by in situ growing cobalt-doped@MnO2 nanocomposite on highly conductive nickel foam (Ni foam) for supercapacitors (SCs). The remarkably high specific surface area of Co dopant provides a larger contacting area for MnO2. In the meantime, the excellent retentions of the hierarchical phase-based pore architecture of the cobalt-doped surface could beneficially condense the electron transportation pathways. In addition, the nickel foam (Ni foam) nanosheets provide charge-transport channels that lead to the outstanding improved electrochemical activities of cobalt-doped@MnO2. The unique cobalt-doped@MnO2 nanocomposite electrode facilitates stable electrochemical architecture, multi-active electrochemical sites, and rapid electro-transports channels; which act as a key factor in enhancing the specific capacitances, stability, and rate capacities. As a result, the cobalt-doped@MnO2 nanocomposite electrode delivered superior electrochemical activities with a specific capacitance of 337.8 F g–1 at 0.5 A g–1; this is greater than pristine MnO2 (277.9 F g–1). The results demonstrate a worthy approach for the designing of high-performance SCs by the grouping of the nanostructured dopant material and metal oxides.

In Situ Grown Mesoporous Structure of Fe-Dopant@NiCoOX@NF Nanoneedles as an Efficient Supercapacitor Electrode Material

“…The R ct of NiCoO x @NF nanowires and Fe-dopant@NiCoO x @NF nanoneedle composite electrodes were approximated to be 0.57 and 0.36 Ω, respectively, revealing that Fe-dopant@NiCoO x @NF nanoneedle composites possess rapid kinetic charge transfers and low resistance internals. Such characteristics favor the paths for ions affected by the Fe-dopant particles to the internal zone of Fe-dopant@NiCoO x @NF nanoneedle composites [ 37 , 38 ]. Impressively, the Fe-dopant@NiCoO x @NF nanoneedle composites sample delivered a smaller circled line with possible vertical slope lines, indicating the ultra-fast rate of ion transport diffusion and adequate connections between electrolytes and electrode samples.…”

“…Therefore, GCD results from varying current densities were procured to quantify the specific capacitances of electrodes. The specific capacitances were measured according to the following equation [ 37 , 38 ]: C = ( I × Δ t )/( m × Δ V ) wherein I is the current density, t is the discharge time, Δ V is the window range for the GCD procedures, and m denotes the mass of the samples.…”

Novel Synthesis of Nano Mg(OH)2 by Means of Hydrothermal Method with Different Surfactants

“…On the other hand, MOH is a fire-resistant and insulating substance as well as an antibacterial agent. By heating the MOH to temperatures above 350 °C, according to Equation ( 1 ), a dehydration reaction occurs, during which MOH is converted to magnesium oxide and water [ 6 , 7 , 8 , 9 , 10 ].…”

Polypyrrole-Coated Low-Crystallinity Iron Oxide Grown on Carbon Cloth Enabling Enhanced Electrochemical Supercapacitor Performance

“…Metal oxides, such as the pseudocapacitor materials (e.g., Co 3 O 4 , MnO 2 , and Bi 2 O 3 ), can offer a higher specific capacitances than EDLC materials because of the charge storage mechanism of surface/near-surface redox reactions [11][12][13][14][15]. Among these metal oxides, Fe 2 O 3 is one of the most interesting negative materials due to its low cost, environmental benignity, wide operating voltage window (0 to −0.1 V vs. Ag/AgCl), and so on [16,17].…”