Three-dimensional NiCo2O4@NiCo2O4 core–shell nanocones arrays for high-performance supercapacitors

Wang, Xiuhua; Yao, Fang; Shi, Bo; Huang, Feifei; Fang, Ruiqi; Que, Ronghui

doi:10.1016/j.cej.2018.03.061

Cited by 257 publications

(76 citation statements)

References 50 publications

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“…Additionally, the reaction kinetics was further researched according to the CV curves by the following formula (4) relating to the peak current (i) and scan rate (v) [Eq. ]:

true normali = normala v^{b}

…”

Section: Resultssupporting

confidence: 60%

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr₂O₄ Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

Zhou

Zhao

et al. 2020

ChemElectroChem

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Hollow metal-organic frameworks (MOFs) and their derived materials have shown fascinating structural complexity, such as diverse morphology, tunable porosity and hierarchical structure, which largely extends their intrinsic applications, especially in electrochemical energy storage and conversion. Herein, a hollow and hierarchical Co-MOF@CoCr 2 O 4 microplate array on nickel foam was successfully prepared through a simple onestep in situ conversion strategy, in which Co-MOF served both as self-supporting etching template and as a self-sacrificing ionexchange template. When used as a battery-type electrode for advanced hybrid supercapacitors, the Co-MOF@CoCr 2 O 4 composite expressed a high specific capacity of 596.8 C g À 1 at 0.4 A g À 1 , excellent rate properties (72.6 % retention rate at 10 A g À 1 compared with the initial capacitance at 0.4 A g À 1 ) and good cycling stability (85.1 % retention over 5000 cycles). Furthermore, a fabricated hybrid supercapacitor device reached a high energy density of 0.4 mWh cm À 2 (34.36 Wh kg À 1 ) at a power density of 2.34 mW cm À 2 (201.03 W kg À 1 ), and superior cycle stability (96.2 % retention over 5000 cycles). These enhanced electrochemical behaviors indicated that this advanced approach can be extended to design various hollow and hierarchical structural MOF/bimetallic-oxide-based composite arrays for high-performance hybrid supercapacitors.[a] Dr.

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“…Additionally, the reaction kinetics was further researched according to the CV curves by the following formula (4) relating to the peak current (i) and scan rate (v) [Eq. ]:

true normali = normala v^{b}

…”

Section: Resultssupporting

confidence: 60%

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr₂O₄ Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

Zhou

Zhao

et al. 2020

ChemElectroChem

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“…The Nyquist plot in Figure 10c displays the relationship between the imaginary part (Z im ) and the real part (Z re ) of the electrode impedance. The initial data point in the high frequency (Figure 10d) measurements shows the initial resistance of the electrode/electrolyte interface, because the effects of mass transfer of the OH − ions on the impedance can be ignored at high frequency [12]. As shown in the magnified view of Figure 10c, the initial resistance was measured as 5.1 Ω and 3.87 Ω for the NiCo 2 O 4 NE and NiCo 2 O 4 /MnO 2 HNE, respectively.…”

Section: Electrochemical Analysis Of Single Electrodementioning

confidence: 99%

Fiber-Shaped Supercapacitors Fabricated Using Hierarchical Nanostructures of NiCo2O4 Nanoneedles and MnO2 Nanoflakes on Roughened Ni Wire

2019

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Electrostatic capacitors have high power density but low energy density. In contrast, batteries and fuel cells have high energy density but low power density. However, supercapacitors can simultaneously achieve both high power density and energy density. Herein, we propose a supercapacitor, in which etched nickel wire was used as a current collector due to its high conductivity. Two redox reactive materials, MnO2 nanoflakes and NiCo2O4 nanoneedles, were used in a hierarchical structure to cover the roughened surface of the Ni wire to maximize the effective surface area. Thus, a specific capacitance, energy density, and power density of 14.4 F/cm3, 2 mWh/cm3, and 0.1 W/cm3, respectively, was obtained via single-electrode experiments. A fiber-shaped supercapacitor was prepared by twisting two electrodes with solid electrolytes made of KOH and polyvinyl alcohol. Although the solid electrolyte had a low ionic conductivity, the energy density and power density were determined to be 0.97 mWh/cm3 and 49.8 mW/cm3, respectively.

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“…As shown in the figure, the Ni 10 /NCO/RGO electrode expresses a relatively smaller semicircle at high frequencies than that of other electrodes, specifying reduced charge transfer resistance exhibited by the Ni 10 /NCO/RGO electrode. Since the effects of mass transfer of the OH - ions from KOH solution on the impedance can be ignored at high frequency, the first data point in the high-frequency region displays the electrode/electrolyte interface’s initial resistance [ 59 ]. Thus, from the high-frequency region Nyquist plot, the initial resistances of Ni 00 /NCO/RGO, Ni 10 /NCO/RGO, Ni 20 /NCO/RGO, and Ni 30 /NCO/RGO electrodes were measured as 3.29, 1.68, 1.86, and 2.81 Ω, respectively.…”

Section: Resultsmentioning

confidence: 99%

NiCo2O4/RGO Hybrid Nanostructures on Surface-Modified Ni Core for Flexible Wire-Shaped Supercapacitor

Shewale

Yun

2021

Nanomaterials

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In this work, we report surface-modified nickel (Ni) wire/NiCo2O4/reduced graphene oxide (Ni/NCO/RGO) electrodes fabricated by a combination of facile solvothermal and hydrothermal deposition methods for wire-shaped supercapacitor application. The effect of Ni wire etching on the microstructural, surface morphological and electrochemical properties of Ni/NCO/RGO electrodes was investigated in detail. On account of the improved hybrid nanostructure and the synergistic effect between spinel-NiCo2O4 hollow microspheres and RGO nanoflakes, the electrode obtained from Ni wire etched for 10 min, i.e., Ni10/NCO/RGO exhibits the lowest initial equivalent resistance (1.68 Ω), and displays a good rate capability with a volumetric capacitance (2.64 F/cm3) and areal capacitance (25.3 mF/cm2). Additionally, the volumetric specific capacitance calculated by considering only active material volume was found to be as high as 253 F/cm3. It is revealed that the diffusion-controlled process related to faradaic volume processes (battery type) contributed significantly to the surface-controlled process of the Ni10/NCO/RGO electrode compared to other electrodes that led to the optimum electrochemical performance. Furthermore, the wire-shaped supercapacitor (WSC) was fabricated by assembling two optimum electrodes in-twisted structure with gel electrolyte and the device exhibited 10 μWh/cm3 (54 mWh/kg) energy density and 4.95 mW/cm3 (27 W/kg) power density at 200 μA. Finally, the repeatability, flexibility, and scalability of WSCs were successfully demonstrated at various device lengths and bending angles.

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Three-dimensional NiCo2O4@NiCo2O4 core–shell nanocones arrays for high-performance supercapacitors

Cited by 257 publications

References 50 publications

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr₂O₄ Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr₂O₄ Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

Fiber-Shaped Supercapacitors Fabricated Using Hierarchical Nanostructures of NiCo2O4 Nanoneedles and MnO2 Nanoflakes on Roughened Ni Wire

NiCo2O4/RGO Hybrid Nanostructures on Surface-Modified Ni Core for Flexible Wire-Shaped Supercapacitor

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Three-dimensional NiCo2O4@NiCo2O4 core–shell nanocones arrays for high-performance supercapacitors

Cited by 257 publications

References 50 publications

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr2O4 Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr2O4 Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

Fiber-Shaped Supercapacitors Fabricated Using Hierarchical Nanostructures of NiCo2O4 Nanoneedles and MnO2 Nanoflakes on Roughened Ni Wire

NiCo2O4/RGO Hybrid Nanostructures on Surface-Modified Ni Core for Flexible Wire-Shaped Supercapacitor

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Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr₂O₄ Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr₂O₄ Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors