Surface Diffusion and Adsorption in Supercapacitors

Eftekhari, Ali

doi:10.1021/acssuschemeng.8b01075

Cited by 75 publications

(55 citation statements)

References 63 publications

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“…Ni‐S possesses a lower resistance than Ni‐NH, indicating a stronger adsorption at the sites of Ni‐S as compared with Ni‐NH. These positive results further confirmed the better rate capability and higher power density of Ni‐S as compared with Ni‐NH . The tail (oblique line) in the low frequency range (region 3) corresponds to the resistances caused by the diffusion of charges along or in between the surfaces of both compounds.…”

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confidence: 63%

Nanostructured Metal–Organic Conjugated Coordination Polymers with Ligand Tailoring for Superior Rechargeable Energy Storage

Xie

Cheng

Cao

et al. 2019

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only high specific capacity but also fast charging ability as well as long cycle life. [1] Although lithium-ion batteries (LIBs) currently dominate the rechargeable battery market, the conventional lithiation mechanism purely based on diffusion-controlled process limits the pursuit of high energy storage, particularly at harsh current density conditions. [2] To achieve next generation of promising energy storage systems, rational design of hybrid electrode materials that integrate the capacitor-like non-faradaic effect with the battery-like faradaic behavior is of great interest. [3,4] Meanwhile, the combination of both characteristics requires the electrode architecture that can rapidly deliver sufficient charges in a short given time period. In this respect, nanostructured redox-active materials with large surface areas and multiredox activities are the most potential candidates. [5][6][7][8][9][10][11][12] One class of redox-active materials that offers high electronic conductivity and tunable electrochemical property is the d-π conjugated coordination compounds. [13][14][15][16][17] Among them, metallically-conductive 2D frameworks have gained considerable efforts as effective materials for field-effect transistors, [18] supercapacitors, [19][20][21] and batteries. [22,23] Nevertheless, their 1D alternatives, [24][25][26] which possess similar repeating units and redox properties are keeping unexplored for electrochemical cells. Such linear conjugated coordination polymers, which are often obtained through the coordination of d 8 metal ions and conjugated tetradentate ligands, are able to provide good chemical stability due to their strong intermolecular interactions. [13,14] Moreover, their energy storage capability can be further stimulated through nanoengineering approaches.From the perspective of molecular design, here we present an innovative strategy to attain high performance conjugated co ordination polymers. Prior to the fabrication of electrodes, nanostructured Ni-NH and Ni-S were prepared in the first place. Differing from literature methods on precise control of the metal centers (M = Ni, Co, Cu, etc.), [20,22] we focus on the alteration of the bridging bonds in organic ligands (Figure 1a). By keeping the metal center remain unchanged, our initiative motivation is to improve the energy storage stability by substituting the bridging bond in metal-coordination complex. Inspired by Conjugated coordination polymers have become an emerging category of redoxactive materials. Although recent studies heavily focus on the tailoring of metal centers in the complexes to achieve stable electrochemical performance, the effect on different substitutions of the bridging bonds has rarely been studied. An innovative tailoring strategy is presented toward the enhancement of the capacity storage and the stability of metal-organic conjugated coordination polymers. Two nanostructured d-π conjugated compounds, Ni[C 6 H 2 (NH) 4 ] n (Ni-NH) and Ni[C 6 H 2 (NH) 2 S 2 ] n (Ni-S), are evaluated and demonstrated to exhibit ...

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supporting

confidence: 63%

Nanostructured Metal–Organic Conjugated Coordination Polymers with Ligand Tailoring for Superior Rechargeable Energy Storage

Xie

Cheng

Cao

et al. 2019

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“…Nyquist plots of the A-SC with the APPH electrodes show the high-, mid-, and lowfrequency regions, corresponding to the electro-transfer limited process, diffusion-limited electrode process and capacitive behavior ( Fig. 5c) 58 , respectively. In the mid-frequency region, the slope of Nyquist plots represents the Warburg impedance (Z w ), indicating the electrolyte diffusion within the electrode 59,60 .…”

Section: Resultsmentioning

confidence: 99%

Cryopolymerization enables anisotropic polyaniline hybrid hydrogels with superelasticity and highly deformation-tolerant electrochemical energy storage

et al. 2020

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The development of energy storage devices that can endure large and complex deformations is central to emerging wearable electronics. Hydrogels made from conducting polymers give rise to a promising integration of high conductivity and versatility in processing. However, the emergence of conducting polymer hydrogels with a desirable network structure cannot be readily achieved using conventional polymerization methods. Here we present a cryopolymerization strategy for preparing an intrinsically stretchable, compressible and bendable anisotropic polyvinyl alcohol/polyaniline hydrogel with a complete recovery of 100% stretching strain, 50% compressing strain and fully bending. Due to its high mechanical strength, superelastic properties and bi-continuous phase structure, the as-obtained anisotropic polyvinyl alcohol/polyaniline hydrogel can work as a stretching/compressing/bending electrode, maintaining its stable output under complex deformations for an all-solid-state supercapacitor. In particular, it achieves an extremely high energy density of 27.5 W h kg −1 , which is among that of state-of-the-art stretchable supercapacitors.

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“…It is also worth mentioning that distorted perfect rectangular shape of the CV is determined by other factors, for instance electrode porosity and internal resistance [79]. Eftekhari stated that the charge accumulation mechanisms in supercapacitors (SCs) are complicated; hence, novel models have to be postulated and emphasized [80,81]. The problem of existing models for double layers from Helmholtz to Graham, is the impossibility of applying these theories on carbon-based capacitor systems [80].…”

Section: Studymentioning

confidence: 99%

Structural, Impedance and Electrochemical Characteristics of Electrical Double Layer Capacitor Devices Based on Chitosan: Dextran Biopolymer Blend Electrolytes

et al. 2020

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This report presents the preparation and characterizations of solid biopolymer blend electrolyte films of chitosan as cationic polysaccharide and anionic dextran (CS: Dextran) doped with ammonium iodide (NH4I) to be utilized as electrolyte and electrode separator in electrical double-layer capacitor (EDLC) devices. FTIR and XRD techniques were used to study the structural behavior of the films. From the FTIR band analysis, shifting and broadening of the bands were observed with increasing salt concentration. The XRD analysis indicates amorphousness of the blended electrolyte samples whereby the peaks underwent broadening. The analysis of the impedance spectra emphasized that incorporation of 40 wt.% of NH4I salt into polymer electrolyte exhibited a relatively high conductivity (5.16 × 10−3 S/cm). The transference number measurement (TNM) confirmed that ion (tion = 0.928) is the main charge carriers in the conduction process. The linear sweep voltammetry (LSV) revealed the extent of durability of the relatively high conducting film which was 1.8 V. The mechanism of charge storage within the fabricated EDLC has been explained to be fully capacitive behavior with no redox peaks appearance in the cyclic voltammogram (CV). From this findings, four important parameters of the EDLC; specific capacitance, equivalent series resistance, energy density and power density were calculated as 67.5 F/g, 160 ohm, 7.59 Wh/kg and 520.8 W/kg, respectively.

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Surface Diffusion and Adsorption in Supercapacitors

Cited by 75 publications

References 63 publications

Nanostructured Metal–Organic Conjugated Coordination Polymers with Ligand Tailoring for Superior Rechargeable Energy Storage

Nanostructured Metal–Organic Conjugated Coordination Polymers with Ligand Tailoring for Superior Rechargeable Energy Storage

Cryopolymerization enables anisotropic polyaniline hybrid hydrogels with superelasticity and highly deformation-tolerant electrochemical energy storage

Structural, Impedance and Electrochemical Characteristics of Electrical Double Layer Capacitor Devices Based on Chitosan: Dextran Biopolymer Blend Electrolytes

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