Pseudocapacitive-battery-like behavior of cobalt manganese nickel sulfide (CoMnNiS) nanosheets grown on Ni-foam by electrodeposition for realizing high capacity

Abstract

Hierarchical interconnected nanosheets (HIN) of cobalt manganese nickel sulfide (CoMnNiS) were synthesized on Ni foam by a simple and economical electrodeposition technique for energy storage application. Sulfonated thin nanosheets of Co, Mn and Ni provide stability of chemical activity, surface functionalization and surface reactivity to the electrode. The fabricated electrode shows a specific capacity of 257.4 mA h g À1 (at 2.5 A g À1 ), measured by galvanostatic charging-discharging (GCD). Both diffusion and capacitive mechanisms in the sulfide layer contribute to the high electrical conductivity.Asymmetric devices CoMnNiS/NiCuO and CoMnNiS/CNT (CNT ¼ carbon nanotubes) were fabricated, providing a maximum operating voltage of 1.7 V and 1 V, specific capacity of 20.8 and 50.8 mA h g À1 , and energy density of 8.4 and 6.3 W h kg À1 corresponding to a power density of 985 and 211 W kg À1 , respectively, at a current density of 0.5 and 0.63 A g À1 . These results demonstrate a novel material for application in energy storage devices as an electrode.

Intercorrelation between physical and electrochemical behavior of nitrogen-doping in graphene for symmetric supercapacitor electrode

“…Therefore the increased defect densities could mainly come from lattice defects and not from nitrogen induced defects [33,45]. Figure S6 shows an increase in the double-layer current of the CV curve with an increased scan rate due to the rapid and fast diffusion of ions between the electrode surface and electrolyte [9]. The quasi-rectangular profile of N-rGO-8 was retained even at a high scan rate, showing the excellent rate capability and low resistance of the material.…”

“…High mechanical strength provides structural stability to the electrode over volumetric change during electrochemical measurement [7]. The high surface area allows better electrolyte ion intercalation between graphene sheets [8], and high electrical conductivity leads to fast electrochemical kinetics [9]. Despite the excellent properties of graphene, the accessible surface area in pristine graphene depends mainly on its layered structure.…”

Effects of morphology on the electrochemical performance of NiFe2O4nanoparticles with battery‐type behavior

“…The CV curves of all samples show clearly separated peaks, which are related to oxidation and reduction processes of reactions occurring on the surface of NiFe 2 O 4 ‐based electrodes, which implies that in our samples a Faradic charge storage mechanism is predominant 9,55 . With increasing the scan rate, the anodic and cathodic peaks shift in the direction of +ve and −ve potential regions, respectively, characterizing a rapid diffusion of ions in the KOH electrolyte 56 . Redox peaks attributed to the dispersal of electrolyte in the materials suggest that NiFe 2 O 4 ‐based electrodes are showing battery‐like behavior 57,58 .…”

“…9,55 With increasing the scan rate, the anodic and cathodic peaks shift in the direction of +ve and −ve potential regions, respectively, characterizing a rapid diffusion of ions in the KOH electrolyte. 56 Redox peaks attributed to the dispersal of electrolyte in the materials suggest that NiFe 2 O 4 -based electrodes are showing battery-like behavior. 57,58 This battery-like behavior and the surface Faradaic redox reaction mechanism can be attributed to the redox transitions of Ni 2+ /Ni 3+ and Fe 2+ /Fe 3+ , which may merge because of the similar redox potential 59,60 (Figure 7A), or not, as shown by the two reduction peaks for sample NF3, as previously reported in the literature.…”

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“…The CV curves of all samples show clearly separated peaks, which are related to oxidation and reduction processes of reactions occurring on the surface of NiFe2O4 based electrodes, which implies that in our samples a faradic charge storage mechanism is predominant [9,69]. With increasing the scan rate the anodic and the cathodic peaks shift in the direction of +ve and -ve potential regions, respectively, characterizing a rapid diffusion of ions in the KOH electrolyte [70]. Redox peaks attributed to the dispersal of electrolyte in the materials suggest that NiFe2O4 based electrodes are showing batterylike behavior [71,72].…”