1
|
Jitvisate M. Direct Measurement of the Differential Capacitance of Deep Eutectic Solvents on Platinum and Glassy Carbon Electrodes. J Phys Chem Lett 2024; 15:9637-9643. [PMID: 39282944 DOI: 10.1021/acs.jpclett.4c02428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2024]
Abstract
Differential capacitance is a crucial parameter that connects the experimental observation of electrical double-layer behavior with theoretical models. However, the current number of reported differential capacitance values for deep eutectic solvents remains limited, making it challenging to verify or refute existing models. In this study, we systematically investigate the differential capacitance in deep eutectic solvents using chronoamperometry. By comparing metal and glassy carbon electrodes across various liquid combinations and ion concentrations, we observed a range of distinct capacitance characteristics. While some findings align with the existing mean-field model for ionic liquids, others clearly reflect the influence of electrode materials, with certain cases resisting full explanation by current theoretical models. These results underscore the importance of selecting appropriate electrode materials in experimental studies of such electrolytes and highlight the need for further theoretical advancements in understanding this complex liquid system.
Collapse
Affiliation(s)
- Monchai Jitvisate
- School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
| |
Collapse
|
2
|
Goloviznina K, Fleischhaker J, Binninger T, Rotenberg B, Ers H, Ivanistsev V, Meissner R, Serva A, Salanne M. Accounting for the Quantum Capacitance of Graphite in Constant Potential Molecular Dynamics Simulations. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2405230. [PMID: 39096068 DOI: 10.1002/adma.202405230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 07/19/2024] [Indexed: 08/04/2024]
Abstract
Molecular dynamics (MD) simulations at a constant electric potential are an essential tool to study electrochemical processes, providing microscopic information on the structural, thermodynamic, and dynamical properties. Despite the numerous advances in the simulation of electrodes, they fail to accurately represent the electronic structure of materials such as graphite. In this work, a simple parameterization method that allows to tune the metallicity of the electrode based on a quantum chemistry calculation of the density of states (DOS) is introduced. As a first illustration, the interface between graphite electrodes and two different liquid electrolytes, an aqueous solution of NaCl and a pure ionic liquid, at different applied potentials are studied. It is shown that the simulations reproduce qualitatively the experimentally-measured capacitance; in particular, they yield a minimum of capacitance at the point of zero charge (PZC), which is due to the quantum capacitance (QC) contribution. An analysis of the structure of the adsorbed liquids allows to understand why the ionic liquid displays a lower capacitance despite its large ionic concentration. In addition to its relevance for the important class of carbonaceous electrodes, this method can be applied to any electrode materials (e.g. 2D materials, conducting polymers, etc), thus enabling molecular simulation studies of complex electrochemical devices in the future.
Collapse
Affiliation(s)
- Kateryna Goloviznina
- CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, Sorbonne Université, F-75005, Paris, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039, Amiens Cedex, France
| | - Johann Fleischhaker
- CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, Sorbonne Université, F-75005, Paris, France
- Institute of Polymers and Composites, Hamburg University of Technology, 21073, Hamburg, Germany
| | - Tobias Binninger
- ICGM, Univ Montpellier, CNRS, ENSCM, 34293, Montpellier, France
- Theory and Computation of Energy Materials (IEK-13), Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Benjamin Rotenberg
- CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, Sorbonne Université, F-75005, Paris, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039, Amiens Cedex, France
| | - Heigo Ers
- University of Tartu, Ravila 14a, Tartu, 51004, Estonia
| | | | - Robert Meissner
- Institute of Polymers and Composites, Hamburg University of Technology, 21073, Hamburg, Germany
- Institute of Surface Science, Helmholtz-Zentrum Hereon, 21502, Geesthacht, Germany
| | - Alessandra Serva
- CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, Sorbonne Université, F-75005, Paris, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039, Amiens Cedex, France
| | - Mathieu Salanne
- CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, Sorbonne Université, F-75005, Paris, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039, Amiens Cedex, France
- Institut Universitaire de France (IUF), 75231, Paris, France
| |
Collapse
|
3
|
Park S, McDaniel JG. Generalized Helmholtz model describes capacitance profiles of ionic liquids and concentrated aqueous electrolytes. J Chem Phys 2024; 160:164709. [PMID: 38651812 DOI: 10.1063/5.0194360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 03/21/2024] [Indexed: 04/25/2024] Open
Abstract
In this work, we propose and validate a generalization of the Helmholtz model that can account for both "bell-shaped" and "camel-shaped" differential capacitance profiles of concentrated electrolytes, the latter being characteristic of ionic liquids. The generalization is based on introducing voltage dependence of both the dielectric constant "ϵr(V)" and thickness "L(V)" of the inner Helmholtz layer, as validated by molecular dynamics (MD) simulations. We utilize MD simulations to study the capacitance profiles of three different electrochemical interfaces: (1) graphite/[BMIm+][BF4-] ionic liquid interface; (2) Au(100)/[BMIm+][BF4-] ionic liquid interface; (3) Au(100)/1M [Na+][Cl-] aqueous interface. We compute the voltage dependence of ϵr(V) and L(V) and demonstrate that the generalized Helmholtz model qualitatively describes both camel-shaped and bell-shaped differential capacitance profiles of ionic liquids and concentrated aqueous electrolytes (in lieu of specific ion adsorption). In particular, the camel-shaped capacitance profile that is characteristic of ionic liquid electrolytes arises simply from combination of the voltage-dependent trends of ϵr(V) and L(V). Furthermore, explicit analysis of the inner layer charge density for both concentrated aqueous and ionic liquid double layers reveal similarities, with these charge distributions typically exhibiting a dipolar region closest to the electrode followed by a monopolar peak at larger distances. It is appealing that a generalized Helmholtz model can provide a unified description of the inner layer structure and capacitance profile for seemingly disparate aqueous and ionic liquid electrolytes.
Collapse
Affiliation(s)
- Suehyun Park
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| | - Jesse G McDaniel
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| |
Collapse
|
4
|
Chen Y, Wippermann K, Rodenbücher C, Suo Y, Korte C. Impedance Analysis of Capacitive and Faradaic Processes in the Pt/[Dema][TfO] Interface. ACS APPLIED MATERIALS & INTERFACES 2024; 16:5278-5285. [PMID: 38247120 PMCID: PMC10835653 DOI: 10.1021/acsami.3c15465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
The electrochemical reaction kinetics, especially the oxygen reduction reaction (ORR) at the cathode, is crucial for the performance of a fuel cell. In this study, the electrochemical processes on a polycrystalline Pt electrode in the presence of protic ionic liquid (PIL) electrolyte diethylmethylammonium triflate [Dema][TfO] are investigated by means of cyclic voltammetry and electrochemical impedance spectroscopy. Since water is continually produced during fuel cell operation, the effect of the water content in the PIL has been intensively analyzed. In order to reveal the dependence of the interfacial reaction characteristics on the electrode potential, the impedance spectra were simulated by an equivalent circuit whose parameters can be related to both Faradaic and capacitive processes. Two interfacial resistances were identified, which differ by about 3 orders of magnitude. The larger one is a charge transfer resistance that can be associated with slow Faradaic processes like the ORR and platinum oxidation/oxide reduction. The smaller resistance is probably linked with fast processes that involve water molecules, such as hydrogen deposition and oxidation. The high- and midfrequency capacitive processes are attributed to "classical" double layer and pseudocapacitive behavior, similar to those identified under nitrogen atmosphere.
Collapse
Affiliation(s)
- Yingzhen Chen
- Institute of Energy and Climate Research─Electrochemical Process Engineering (IEK-14), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- RWTH Aachen University, 52062 Aachen, Germany
| | - Klaus Wippermann
- Institute of Energy and Climate Research─Electrochemical Process Engineering (IEK-14), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Christian Rodenbücher
- Institute of Energy and Climate Research─Electrochemical Process Engineering (IEK-14), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Yanpeng Suo
- Institute of Energy and Climate Research─Electrochemical Process Engineering (IEK-14), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- RWTH Aachen University, 52062 Aachen, Germany
| | - Carsten Korte
- Institute of Energy and Climate Research─Electrochemical Process Engineering (IEK-14), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- RWTH Aachen University, 52062 Aachen, Germany
| |
Collapse
|
5
|
Wang Y, Tian G. Theoretical Insight into the Imidazolium-Based Ionic Liquid Interface Structure and Differential Capacitance on Au(111): Effects of the Cationic Substituent Group. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:14231-14245. [PMID: 37751408 DOI: 10.1021/acs.langmuir.3c01381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Electric double layers (EDLs) play a key role in the electrochemical and energy storage of supercapacitors. It is important to understand the structure and properties of EDLs. In this work, quantum chemical calculations and molecular dynamics (MD) simulations are used to study the microstructure of EDLs of four different substituents of imidazolium-based bis(trifluoromethylsulfonyl)imide ionic liquids (ILs) on the Au(111) surface. It is shown that the particle interactions influence the different arrangements of the anion and cation. More alkyl substitutions and longer alkyl chains result in a higher ELUMO and thus a stronger interaction energy between cations and electrodes. Strong interactions produce linear patterns of anions/cations on the electrode and a maximum value of differential capacitance near PZC, whereas weak interactions generate worm-like patterns of anions/cations on Au(111) and a minimum value of differential capacitance near the PZC. We hold the opinion that the alkyl substitution has more effects on the EDLs. Our analysis provides a new perspective on EDLs structures at the atomic and molecular level. This study provides a good basis and guidance for further understanding the interface phenomena and characteristics of ionic liquids in electrochemical and energy device applications.
Collapse
Affiliation(s)
- Yue Wang
- State Key Laboratory of Complex Non-ferrous Metal Resource Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China
- Yunnan Open University, Kunming 650223, China
| | - Guocai Tian
- State Key Laboratory of Complex Non-ferrous Metal Resource Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China
| |
Collapse
|
6
|
Ntim S, Sulpizi M. Molecular dynamics simulations of electrified interfaces including the metal polarisation. Phys Chem Chem Phys 2023; 25:22619-22625. [PMID: 37555300 DOI: 10.1039/d3cp01472j] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Understanding electrified interfaces requires an accurate description of the electric double layer which also takes into account the metal polarisation. Here we present a simple approach to the molecular dynamics simulation of electrified interfaces which combines fixed charges and a core-shell model for the description of the polarisable electron density on the metal electrode. The approach has been applied to the Au(111) surface in contact with a NaCl aqueous electrolyte solution in order to calculate the differential capacitance and to gain a detailed picture of the charging mechanism. Metal polarisation enhances the interfacial capacitance with a difference between the cathode and anode. In particular, we find that the influence of the metal polarisation on the electric double layer depends on the ion's solvation shell structure and, for the investigated interface, is more important at the cathode, where it modifies the sodium ion distribution.
Collapse
Affiliation(s)
- Samuel Ntim
- Institut für Physik, Johannes Gutenberg Universität, Staudingerweg 7, 55128-Mainz, Germany
| | - Marialore Sulpizi
- Institut für Physik, Ruhr Universität Bochum, Universitätstrasse 150, 44801 Bochum, Germany.
| |
Collapse
|
7
|
Janssen M, Verkholyak T, Kuzmak A, Kondrat S. Optimising nanoporous supercapacitors for heat-to-electricity conversion. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.121093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
8
|
Rabiei Jildani S, Keshavarzi E. Influence of cation shape asymmetry on the interfacial features and capacitance curve of ionic liquids inside the spherical cavity of the porous electrode as an ionic liquid-based supercapacitor. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
9
|
Jeanmairet G, Rotenberg B, Salanne M. Microscopic Simulations of Electrochemical Double-Layer Capacitors. Chem Rev 2022; 122:10860-10898. [PMID: 35389636 PMCID: PMC9227719 DOI: 10.1021/acs.chemrev.1c00925] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Indexed: 12/19/2022]
Abstract
Electrochemical double-layer capacitors (EDLCs) are devices allowing the storage or production of electricity. They function through the adsorption of ions from an electrolyte on high-surface-area electrodes and are characterized by short charging/discharging times and long cycle-life compared to batteries. Microscopic simulations are now widely used to characterize the structural, dynamical, and adsorption properties of these devices, complementing electrochemical experiments and in situ spectroscopic analyses. In this review, we discuss the main families of simulation methods that have been developed and their application to the main family of EDLCs, which include nanoporous carbon electrodes. We focus on the adsorption of organic ions for electricity storage applications as well as aqueous systems in the context of blue energy harvesting and desalination. We finally provide perspectives for further improvement of the predictive power of simulations, in particular for future devices with complex electrode compositions.
Collapse
Affiliation(s)
- Guillaume Jeanmairet
- Sorbonne
Université, CNRS, Physico-chimie
des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau
sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS
3459, 80039 Amiens, France
| | - Benjamin Rotenberg
- Sorbonne
Université, CNRS, Physico-chimie
des Electrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau
sur le Stockage Électrochimique de l’Énergie
(RS2E), FR CNRS 3459, 80039 Amiens, France
| | - Mathieu Salanne
- Réseau
sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS
3459, 80039 Amiens, France
- Sorbonne
Université, CNRS, Physico-chimie
des Electrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Institut
Universitaire de France (IUF), 75231 Paris Cedex 05, France
| |
Collapse
|
10
|
Sundararaman R, Vigil-Fowler D, Schwarz K. Improving the Accuracy of Atomistic Simulations of the Electrochemical Interface. Chem Rev 2022; 122:10651-10674. [PMID: 35522135 PMCID: PMC10127457 DOI: 10.1021/acs.chemrev.1c00800] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Atomistic simulation of the electrochemical double layer is an ambitious undertaking, requiring quantum mechanical description of electrons, phase space sampling of liquid electrolytes, and equilibration of electrolytes over nanosecond time scales. All models of electrochemistry make different trade-offs in the approximation of electrons and atomic configurations, from the extremes of classical molecular dynamics of a complete interface with point-charge atoms to correlated electronic structure methods of a single electrode configuration with no dynamics or electrolyte. Here, we review the spectrum of simulation techniques suitable for electrochemistry, focusing on the key approximations and accuracy considerations for each technique. We discuss promising approaches, such as enhanced sampling techniques for atomic configurations and computationally efficient beyond density functional theory (DFT) electronic methods, that will push electrochemical simulations beyond the present frontier.
Collapse
Affiliation(s)
- Ravishankar Sundararaman
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
| | - Derek Vigil-Fowler
- Materials, Chemical, and Computational Science Directorate, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Kathleen Schwarz
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| |
Collapse
|
11
|
Schlaich A, Jin D, Bocquet L, Coasne B. Electronic screening using a virtual Thomas-Fermi fluid for predicting wetting and phase transitions of ionic liquids at metal surfaces. NATURE MATERIALS 2022; 21:237-245. [PMID: 34764431 DOI: 10.1038/s41563-021-01121-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Of relevance to energy storage, electrochemistry and catalysis, ionic and dipolar liquids display unexpected behaviours-especially in confinement. Beyond adsorption, over-screening and crowding effects, experiments have highlighted novel phenomena, such as unconventional screening and the impact of the electronic nature-metallic versus insulating-of the confining surface. Such behaviours, which challenge existing frameworks, highlight the need for tools to fully embrace the properties of confined liquids. Here we introduce a novel approach that involves electronic screening while capturing molecular aspects of interfacial fluids. Although available strategies consider perfect metal or insulator surfaces, we build on the Thomas-Fermi formalism to develop an effective approach that deals with any imperfect metal between these asymptotes. Our approach describes electrostatic interactions within the metal through a 'virtual' Thomas-Fermi fluid of charged particles, whose Debye length sets the screening length λ. We show that this method captures the electrostatic interaction decay and electrochemical behaviour on varying λ. By applying this strategy to an ionic liquid, we unveil a wetting transition on switching from insulating to metallic conditions.
Collapse
Affiliation(s)
- Alexander Schlaich
- Université Grenoble Alpes, CNRS, LIPhy, Grenoble, France
- Institute for Computational Physics, University of Stuttgart, Stuttgart, Germany
| | - Dongliang Jin
- Université Grenoble Alpes, CNRS, LIPhy, Grenoble, France
| | - Lyderic Bocquet
- Laboratoire de Physique de l'Ecole Normale Supérieure, CNRS, Université PSL, Sorbonne Université, Paris, Paris, France
| | - Benoit Coasne
- Université Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
| |
Collapse
|
12
|
Shandilya A, Schwarz K, Sundararaman R. Interfacial water asymmetry at ideal electrochemical interfaces. J Chem Phys 2022; 156:014705. [PMID: 34998343 DOI: 10.1063/5.0076038] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Controlling electrochemical reactivity requires a detailed understanding of the charging behavior and thermodynamics of the electrochemical interface. Experiments can independently probe the overall charge response of the electrochemical double layer by capacitance measurements and the thermodynamics of the inner layer with potential of maximum entropy measurements. Relating these properties by computational modeling of the electrochemical interface has so far been challenging due to the low accuracy of classical molecular dynamics (MD) for capacitance and the limited time and length scales of ab initio MD. Here, we combine large ensembles of long-time-scale classical MD simulations with charge response from electronic density functional theory to predict the potential-dependent capacitance of a family of ideal aqueous electrochemical interfaces with different peak capacitances. We show that while the potential of maximum capacitance varies, this entire family exhibits an electrode charge of maximum capacitance (CMC) between -2.9 and -2.2 μC/cm2, regardless of the details in the electronic response. Simulated heating of the same interfaces reveals that the entropy peaks at a charge of maximum entropy (CME) of -5.1 ± 0.6 μC/cm2, in agreement with experimental findings for metallic electrodes. The CME and CMC both indicate asymmetric response of interfacial water that is stronger for negatively charged electrodes, while the difference between CME and CMC illustrates the richness in behavior of even the ideal electrochemical interface.
Collapse
Affiliation(s)
- Abhishek Shandilya
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| | - Kathleen Schwarz
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Ravishankar Sundararaman
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| |
Collapse
|
13
|
Microscopic origin of the effect of substrate metallicity on interfacial free energies. Proc Natl Acad Sci U S A 2021; 118:2108769118. [PMID: 34876519 DOI: 10.1073/pnas.2108769118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2021] [Indexed: 11/18/2022] Open
Abstract
We investigate the effect of the metallic character of solid substrates on solid-liquid interfacial thermodynamics using molecular simulations. Building on the recent development of a semiclassical Thomas-Fermi model to tune the metallicity in classical molecular dynamics simulations, we introduce a thermodynamic integration framework to compute the evolution of the interfacial free energy as a function of the Thomas-Fermi screening length. We validate this approach against analytical results for empty capacitors and by comparing the predictions in the presence of an electrolyte with values determined from the contact angle of droplets on the surface. The general expression derived in this work highlights the role of the charge distribution within the metal. We further propose a simple model to interpret the evolution of the interfacial free energy with voltage and Thomas-Fermi length, which allows us to identify the charge correlations within the metal as the microscopic origin of the evolution of the interfacial free energy with the metallic character of the substrate. This methodology opens the door to the molecular-scale study of the effect of the metallic character of the substrate on confinement-induced transitions in ionic systems, as reported in recent atomic force microscopy and surface force apparatus experiments.
Collapse
|
14
|
Wu Y, Ye J, Jiang G, Ni K, Shu N, Taberna P, Zhu Y, Simon P. Electrochemical Characterization of Single Layer Graphene/Electrolyte Interface: Effect of Solvent on the Interfacial Capacitance. Angew Chem Int Ed Engl 2021; 60:13317-13322. [PMID: 33555100 PMCID: PMC8252098 DOI: 10.1002/anie.202017057] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Indexed: 11/21/2022]
Abstract
The development of the basic understanding of the charge storage mechanisms in electrodes for energy storage applications needs deep characterization of the electrode/electrolyte interface. In this work, we studied the charge of the double layer capacitance at single layer graphene (SLG) electrode used as a model material, in neat (EMIm-TFSI) and solvated (with acetonitrile) ionic liquid electrodes. The combination of electrochemical impedance spectroscopy and gravimetric electrochemical quartz crystal microbalance (EQCM) measurements evidence that the presence of solvent drastically increases the charge carrier density at the SLG/ionic liquid interface. The capacitance is thus governed not only by the electronic properties of the graphene, but also by the specific organization of the electrolyte side at the SLG surface originating from the strong interactions existing between the EMIm+ cations and SLG surface. EQCM measurements also show that the carbon structure, with the presence of sp2 carbons, affects the charge storage mechanism by favoring counter-ion adsorption on SLG electrode versus ion exchange mechanism in amorphous porous carbons.
Collapse
Affiliation(s)
- Yih‐Chyng Wu
- Université Paul SabatierCIRIMAT UMR CNRS 5085118 route de Narbonne31062ToulouseFrance
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E)FR CNRS 3459France
| | - Jianglin Ye
- Hefei National Research Center for Physical Sciences at the Microscale, &CAS Key Laboratory of Materials for Energy Conversion, &Department of Materials Science and Engineering, &iChEMUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Gengping Jiang
- College of ScienceWuhan University of Science and TechnologyWuhan430080China
| | - Kun Ni
- Hefei National Research Center for Physical Sciences at the Microscale, &CAS Key Laboratory of Materials for Energy Conversion, &Department of Materials Science and Engineering, &iChEMUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Na Shu
- Hefei National Research Center for Physical Sciences at the Microscale, &CAS Key Laboratory of Materials for Energy Conversion, &Department of Materials Science and Engineering, &iChEMUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Pierre‐Louis Taberna
- Université Paul SabatierCIRIMAT UMR CNRS 5085118 route de Narbonne31062ToulouseFrance
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E)FR CNRS 3459France
| | - Yanwu Zhu
- Hefei National Research Center for Physical Sciences at the Microscale, &CAS Key Laboratory of Materials for Energy Conversion, &Department of Materials Science and Engineering, &iChEMUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Patrice Simon
- Université Paul SabatierCIRIMAT UMR CNRS 5085118 route de Narbonne31062ToulouseFrance
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E)FR CNRS 3459France
| |
Collapse
|
15
|
Voroshylova IV, Ers H, Koverga V, Docampo-Álvarez B, Pikma P, Ivaništšev VB, Cordeiro M. Ionic liquid–metal interface: The origins of capacitance peaks. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138148] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
16
|
Electrochemical Characterization of Single Layer Graphene/Electrolyte Interface: Effect of Solvent on the Interfacial Capacitance. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202017057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
17
|
Model of electrical double layer structure at semi-metallic electrode/ionic liquid interface. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2020.137555] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
18
|
Scalfi L, Dufils T, Reeves KG, Rotenberg B, Salanne M. A semiclassical Thomas–Fermi model to tune the metallicity of electrodes in molecular simulations. J Chem Phys 2020; 153:174704. [DOI: 10.1063/5.0028232] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Laura Scalfi
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
| | - Thomas Dufils
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
| | - Kyle G. Reeves
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
| | - Benjamin Rotenberg
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
| | - Mathieu Salanne
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
- Institut Universitaire de France (IUF), 75231 Paris Cedex 05, France
| |
Collapse
|
19
|
Bhardwaj K, Parvis F, Wang Y, Blanchard GJ, Swain GM. Effect of Surface Oxygen on the Wettability and Electrochemical Properties of Boron-Doped Nanocrystalline Diamond Electrodes in Room-Temperature Ionic Liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5717-5729. [PMID: 32348147 DOI: 10.1021/acs.langmuir.0c00294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This paper reports on how the surface chemistry of boron-doped nanocrystalline diamond (BDD) thin-film electrodes (H vs O) affects the wettability and electrochemical properties in two room-temperature ionic liquids (RTILs): [BMIM][PF6] and [HMIM][PF6]. Comparative measurements were made in 0.5 mol L-1 H2SO4. The BDD electrodes were modified by microwave or radio-frequency (RF) plasma treatment in H2 (H-BDD), Ar (Ar-BDD), or O2 (O-BDD). These modifications produced low-, medium-, and high-oxygen surface coverages. Atomic O/C ratios, as determined by X-ray photoelectron spectroscopy (XPS), were 0.01 for H-BDD, 0.08 for Ar-BDD, and 0.17 for O-BDD. The static contact angle of ultrapure water on the modified electrodes decreased from 110° (H-BDD) to 41° (O-BDD) with increasing surface oxygen coverage, as expected as the surface becomes more hydrophilic. Interestingly, the opposite trend was seen for both RTILs as the contact angle increased from 20° (H-BDD) to 50° (O-BDD) with increasing surface oxygen coverage. The cyclic voltammetric background current and potential-dependent capacitance in both RTILs were largest for BDD electrodes with the lowest O/C ratio (H-BDD) and smallest contact angle. Slightly larger voltammetric background currents and capacitance were observed in [HMIM][PF6] than in [BMIM][PF6]. Capacitance values ranged from 8 to 16 μF cm-2 over the potential range for H-BDD and from 4 to 6 μF cm-2 for O-BDD. The opposite trend was observed in H2SO4 as the voltammetric background current and capacitance were largest for BDD electrodes with the highest O/C ratio (O-BDD) and smallest contact angle. In summary, reducing the surface oxygen on BDD electrodes increases the wettability to two RTILs and this increases the voltammetric background current and capacitance.
Collapse
Affiliation(s)
- Kirti Bhardwaj
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
- Department of Chemical Engineering and Material Science, Michigan State University, 428 South Shaw Lane, East Lansing, Michigan 48824-1226, United States
| | - FatemehSadat Parvis
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
| | - Yufeng Wang
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
| | - Gary J Blanchard
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
| | - Greg M Swain
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824-1322, United States
- Department of Chemical Engineering and Material Science, Michigan State University, 428 South Shaw Lane, East Lansing, Michigan 48824-1226, United States
| |
Collapse
|
20
|
Dudka M, Kondrat S, Bénichou O, Kornyshev AA, Oshanin G. Superionic liquids in conducting nanoslits: A variety of phase transitions and ensuing charging behavior. J Chem Phys 2019; 151:184105. [PMID: 31731872 DOI: 10.1063/1.5127851] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We develop a theory of charge storage in ultranarrow slitlike pores of nanostructured electrodes. Our analysis is based on the Blume-Capel model in an external field, which we solve analytically on a Bethe lattice. The obtained solutions allow us to explore the complete phase diagram of confined ionic liquids in terms of the key parameters characterizing the system, such as pore ionophilicity, interionic interaction energy, and voltage. The phase diagram includes the lines of first- and second-order, direct and re-entrant phase transitions, which are manifested by singularities in the corresponding capacitance-voltage plots. Testing our predictions experimentally requires monodisperse, conducting ultranarrow slit pores, to permit only one layer of ions, and thick pore walls, to prevent interionic interactions across the pore walls. However, some qualitative features, which distinguish the behavior of ionophilic and ionophobic pores and their underlying physics, may emerge in future experimental studies of more complex electrode structures.
Collapse
Affiliation(s)
- Maxym Dudka
- Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii St., 79011 Lviv, Ukraine
| | - Svyatoslav Kondrat
- Department of Complex Systems, Institute of Physical Chemistry, PAS, Kasprzaka 44/52, Warsaw, Poland
| | - Olivier Bénichou
- Sorbonne Université, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, LPTMC (UMR CNRS 7600), 75252 Paris Cedex 05, France
| | - Alexei A Kornyshev
- Department of Chemistry, Molecular Sciences Research Hub, White City Campus, London W12 0BZ, United Kingdom
| | - Gleb Oshanin
- Sorbonne Université, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, LPTMC (UMR CNRS 7600), 75252 Paris Cedex 05, France
| |
Collapse
|
21
|
Zhang Y, Cummings PT. Effects of Solvent Concentration on the Performance of Ionic-Liquid/Carbon Supercapacitors. ACS APPLIED MATERIALS & INTERFACES 2019; 11:42680-42689. [PMID: 31608619 DOI: 10.1021/acsami.9b09939] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We use molecular dynamics simulations to investigate the effects of solvent concentration on the bulk properties of an ion liquid electrolyte and the electrochemical performance on carbon-based electrodes, including pristine graphene, oxidized graphene, graphene armchair edge, graphene zigzag edge, onion-like carbon, and slit-pore carbon. We find that diluting the electrolyte reduces the number of ion pairs in the bulk and improves ion dynamics. The capacitance of the two-edge electrodes decreases monotonically as the solvent concentration increases, while the capacitance of other nonedge electrodes exhibits nonmonotonic behavior and a capacitance maximum is observed. Further analyses on the electric double layer reveals two competing factors: solvation reduces the charge overscreening effect, but it also causes the dilution of absorbed ion concentration. While the former increases the capacitance in the low dilution regime, the latter decreases the capacitance in the high dilution regime. In addition, the dilution also significantly improves the ion dynamics at the interface. Our simulation results demonstrate that diluting an ionic liquid electrolyte could potentially boost the power density while maintaining or even slightly increasing the energy density with a careful selection of solvent concentrations on a nonedge carbon electrode.
Collapse
Affiliation(s)
- Yu Zhang
- Department of Chemical and Biomolecular Engineering , Vanderbilt University , Nashville , Tennessee 37225 , United States
| | - Peter T Cummings
- Department of Chemical and Biomolecular Engineering , Vanderbilt University , Nashville , Tennessee 37225 , United States
| |
Collapse
|
22
|
Hydrothermal and peat-derived carbons as electrode materials for high-efficient electrical double-layer capacitors. J APPL ELECTROCHEM 2019. [DOI: 10.1007/s10800-019-01364-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
23
|
Differential capacitance of ionic liquid interface with graphene: The effects of correlation and finite size of ions. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.06.171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
24
|
Electric double layer structure and capacitance of imidazolium-based ionic liquids with FSI− and Tf− anions at graphite electrode by molecular dynamic simulations. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.113452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
25
|
Adsorption of anions on bismuth and cadmium single crystal plane electrodes from various solvents and ionic liquid mixtures. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.06.179] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
26
|
Voroshylova IV, Lembinen M, Ers H, Mišin M, Koverga VA, Pereira CM, Ivaništšev VB, Cordeiro MND. On the role of the surface charge plane position at Au(hkl)–BMImPF6 interfaces. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.05.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
27
|
Li J, Pham PHQ, Zhou W, Pham TD, Burke PJ. Carbon-Nanotube-Electrolyte Interface: Quantum and Electric Double Layer Capacitance. ACS NANO 2018; 12:9763-9774. [PMID: 30226746 PMCID: PMC6429958 DOI: 10.1021/acsnano.8b01427] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present a comprehensive study of the electrochemical capacitance between a one-dimensional electronic material and an electrolyte. In contrast to a conventional, planar electrode, the nanoscale dimension of the electrode (with diameter smaller than the Debye length and approaching the size of the ions in solution) qualitatively changes the capacitance, which we measure and model herein. Furthermore, the finite density of states in these low dimensional electronic systems results in a quantum capacitance, which is comparable to the electrochemical capacitance. Using electrochemical impedance spectroscopy (EIS), we measure the ensemble average, complex, frequency dependent impedance (from 0.1 Hz to 1 MHz) between a purified (99.9%) semiconducting nanotube network and an aqueous electrolyte (KCl) at different concentrations between 10 mM and 1 M. The potential dependence of the capacitance is convoluted with the potential dependence of the in-plane conductance of the nanotube network, which we model using a transmission-line model to account for the frequency dependent in-plane impedance as well as the total interfacial impedance between the network and the electrolyte. The ionic strength dependence of the capacitance is expected to have a root cause from the double layer capacitance, which we model using a modified Poisson-Boltzmann equation. The relative contributions from those two capacitances can be quantitatively decoupled. We find a total capacitance per tube of 0.67-1.13 fF/μm according to liquid gate potential varying from -0.5 to -0.7 V.
Collapse
Affiliation(s)
- Jinfeng Li
- Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
| | - Phi H. Q. Pham
- Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697, United States
| | - Weiwei Zhou
- Integrated Nanosystems Research Facility, University of California, Irvine, California 92697, United States
| | - Ted D. Pham
- Department of Biomedical Engineering, University of California, Irvine, California 92697, United States
| | - Peter J. Burke
- Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697, United States
- Integrated Nanosystems Research Facility, University of California, Irvine, California 92697, United States
- Department of Biomedical Engineering, University of California, Irvine, California 92697, United States
- Department of Electrical Engineering and Computer Science, University of California, Irvine, California 92697, United States
| |
Collapse
|
28
|
Chen M, Goodwin ZA, Feng G, Kornyshev AA. On the temperature dependence of the double layer capacitance of ionic liquids. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.11.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
29
|
Daniels L, Scott M, Mišković Z. The effects of dielectric decrement and finite ion size on differential capacitance of electrolytically gated graphene. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.04.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
30
|
Jitvisate M, Seddon JRT. Direct Measurement of the Differential Capacitance of Solvent-Free and Dilute Ionic Liquids. J Phys Chem Lett 2018; 9:126-131. [PMID: 29256620 PMCID: PMC6150683 DOI: 10.1021/acs.jpclett.7b02946] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Differential capacitance is a key quantity in the understanding of electrical double-layer charging of electrolytes. However, experimental observations of ionic liquid systems are controversial, inconsistent, and often unable of confirming or refuting existing theories as well as highlighting discrepancies between the measurement techniques. We study the differential capacitance in both pure and dilute ionic liquids at room temperature. Using chronoamperometry to measure the differential capacitance of the liquids at a polycrystalline platinum electrode, we find good agreement between the measured capacitance curves and the extended mean-field model of Goodwin-Kornyshev [Goodwin, Z. A.; et al. Electrochim. Acta. 2017, 225, 190-197]. A crossover is found from the pure to the dilute regime, as shown by a transition from a camel-shape capacitance curve to a U-like one, together with a nonmonotonic dependence of capacitance with electrolyte concentration.
Collapse
Affiliation(s)
- Monchai Jitvisate
- Nanoionics, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - James R T Seddon
- Physics of Complex Fluids, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| |
Collapse
|
31
|
Wippermann K, Giffin J, Kuhri S, Lehnert W, Korte C. The influence of water content in a proton-conducting ionic liquid on the double layer properties of the Pt/PIL interface. Phys Chem Chem Phys 2017; 19:24706-24723. [PMID: 28861561 DOI: 10.1039/c7cp04003b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The influence of the water content of 2-sulfoethylmethylammonium trifluoromethanesulfonate [2-Sema][TfO] on the double layer properties of the interface of platinum and the proton conducting ionic liquid (PIL) is investigated by means of impedance spectroscopy and cyclic voltammetry. By fitting the impedance spectra as complex capacitances, up to four differential double layer capacitances and corresponding time constants are obtained, depending on the potential (U = 0-1.6 V/RHE), water content (0.7-6.1 wt%) and temperature (T = 70-110 °C). Within the whole potential range investigated, a high frequency capacitance, C1, and a low frequency capacitance, C2, can be calculated. In the potential region of hydrogen underpotential deposition (HUPD), C1 can be separated into two parts, C1a and C1b. Whereas the high frequency capacitive processes can mainly be attributed to ion transport processes in the double layer, the low frequency process is ascribed to changes in the interfacial layer, including ad-/desorption and Faradaic processes. Alternative interpretations regarding the reorientation of ions, reconstruction of the metal surface and partial electron transfer between anions and Pt are considered.
Collapse
Affiliation(s)
- K Wippermann
- Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research - Fuel Cells (IEK-3), 52425 Jülich, Germany.
| | | | | | | | | |
Collapse
|
32
|
Influence of chemical composition of electrode material on the differential capacitance characteristics of the ionic liquid | electrode interface. Electrochem commun 2017. [DOI: 10.1016/j.elecom.2017.07.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
33
|
Specific adsorption from an ionic liquid: impedance study of iodide ion adsorption from a pure halide ionic liquid at bismuth single crystal planes. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.07.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
34
|
|
35
|
Twenty years of the Journal of Solid State Electrochemistry. J Solid State Electrochem 2017. [DOI: 10.1007/s10008-017-3648-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
36
|
Ma K, Wang X, Cui Y, Lin F, Deng C, Shi H. Understanding the graphene-based electric double layer from dielectric perspective: A density functional study. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
37
|
Goodwin ZA, Feng G, Kornyshev AA. Mean-Field Theory of Electrical Double Layer In Ionic Liquids with Account of Short-Range Correlations. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.12.092] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
38
|
Burt R, Breitsprecher K, Daffos B, Taberna PL, Simon P, Birkett G, Zhao XS, Holm C, Salanne M. Capacitance of Nanoporous Carbon-Based Supercapacitors Is a Trade-Off between the Concentration and the Separability of the Ions. J Phys Chem Lett 2016; 7:4015-4021. [PMID: 27661760 DOI: 10.1021/acs.jpclett.6b01787] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nanoporous carbon-based supercapacitors store electricity through adsorption of ions from the electrolyte at the surface of the electrodes. Room temperature ionic liquids, which show the largest ion concentrations among organic liquid electrolytes, should in principle yield larger capacitances. Here, we show by using electrochemical measurements that the capacitance is not significantly affected when switching from a pure ionic liquid to a conventional organic electrolyte using the same ionic species. By performing additional molecular dynamics simulations, we interpret this result as an increasing difficulty of separating ions of opposite charges when they are more concentrated, that is, in the absence of a solvent that screens the Coulombic interactions. The charging mechanism consistently changes with ion concentration, switching from counterion adsorption in the diluted organic electrolyte to ion exchange in the pure ionic liquid. Contrarily to the capacitance, in-pore diffusion coefficients largely depend on the composition, with a noticeable slowing of the dynamics in the pure ionic liquid.
Collapse
Affiliation(s)
- Ryan Burt
- School of Chemical Engineering, University of Queensland , St. Lucia, Brisbane, Queensland 4072, Australia
| | - Konrad Breitsprecher
- Institute for Computational Physics, University of Stuttgart , Allmandring 3, 70569 Stuttgart, Germany
| | - Barbara Daffos
- CIRIMAT, Université de Toulouse, CNRS, INPT, UPS , 118 route de Narbonne, 31062 Toulouse Cedex 9, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens, France
| | - Pierre-Louis Taberna
- CIRIMAT, Université de Toulouse, CNRS, INPT, UPS , 118 route de Narbonne, 31062 Toulouse Cedex 9, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens, France
| | - Patrice Simon
- CIRIMAT, Université de Toulouse, CNRS, INPT, UPS , 118 route de Narbonne, 31062 Toulouse Cedex 9, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens, France
| | - Greg Birkett
- School of Chemical Engineering, University of Queensland , St. Lucia, Brisbane, Queensland 4072, Australia
| | - X S Zhao
- School of Chemical Engineering, University of Queensland , St. Lucia, Brisbane, Queensland 4072, Australia
| | - Christian Holm
- Institute for Computational Physics, University of Stuttgart , Allmandring 3, 70569 Stuttgart, Germany
| | - Mathieu Salanne
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens, France
- Sorbonne Universités, UPMC Univ Paris 06 , CNRS, Laboratoire PHENIX, F-75005 Paris, France
- Maison de la Simulation, CEA, CNRS, University Paris-Sud, UVSQ, Université Paris Saclay , F-91191 Gif-sur-Yvette, France
| |
Collapse
|
39
|
Schmidt E, Shi S, Ruden PP, Frisbie CD. Characterization of the Electric Double Layer Formation Dynamics of a Metal/Ionic Liquid/Metal Structure. ACS APPLIED MATERIALS & INTERFACES 2016; 8:14879-14884. [PMID: 27213215 DOI: 10.1021/acsami.6b04065] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Although ionic liquids (ILs) have been used extensively in recent years as a high-capacitance "dielectric" in electric double layer transistors, the dynamics of the double layer formation have remained relatively unexplored. Better understanding of the dynamics and relaxation processes involved in electric double layer formation will guide device optimization, particularly with regard to switching speed. In this paper, we explore the dynamical characteristics of an IL in a metal/ionic liquid/metal (M/IL/M) capacitor. In particular, we examine a Au/IL/Au structure where the IL is 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate. The experiments consist of frequency-dependent impedance measurements and time-dependent current vs voltage measurements for applied linear voltage ramps and abrupt voltage steps. The parameters of an equivalent circuit model are determined by fits to the impedance vs frequency data and subsequently verified by calculating the current vs voltage characteristics for the applied potential profiles. The data analysis indicates that the dynamics of the structure are characterized by a wide distribution of relaxation times spanning the range of less than microseconds to longer than seconds. Possible causes for these time scales are discussed.
Collapse
Affiliation(s)
- Elliot Schmidt
- Department of Chemical Engineering and Materials Science and ‡Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis 55455, United States
| | - Sha Shi
- Department of Chemical Engineering and Materials Science and ‡Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis 55455, United States
| | - P Paul Ruden
- Department of Chemical Engineering and Materials Science and ‡Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis 55455, United States
| | - C Daniel Frisbie
- Department of Chemical Engineering and Materials Science and ‡Department of Electrical and Computer Engineering, University of Minnesota , Minneapolis 55455, United States
| |
Collapse
|
40
|
Jäckel N, Weingarth D, Schreiber A, Krüner B, Zeiger M, Tolosa A, Aslan M, Presser V. Performance evaluation of conductive additives for activated carbon supercapacitors in organic electrolyte. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.01.065] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
41
|
Kondrat S, Kornyshev AA. Pressing a spring: what does it take to maximize the energy storage in nanoporous supercapacitors? NANOSCALE HORIZONS 2016; 1:45-52. [PMID: 32260601 DOI: 10.1039/c5nh00004a] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We discuss the nonlinear effects and efficiency of charge storage in supercapacitors with nanoporous electrodes and ionic liquids, and demonstrate that to maximize the stored energy, it may be beneficial to create 'obstacles' or 'difficulties' in charging. This can be achieved by making thermodynamically unfavourable conditions for ions inside nanopores, or more favourable outside. We show by means of Monte Carlo simulations that such 'ionophobic' pores store energy more efficiently and can provide equivalent or even better energy capacity. Since the recent analysis predicts much faster charging of ionophobic nanopores, we conclude that such pores offer a better option for simultaneous energy/power optimization.
Collapse
|
42
|
Müller C, Németh K, Vesztergom S, Pajkossy T, Jacob T. The interface between HOPG and 1-butyl-3-methyl-imidazolium hexafluorophosphate. Phys Chem Chem Phys 2016; 18:916-25. [DOI: 10.1039/c5cp05406k] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The interface between highly oriented pyrolytic graphite (HOPG) and 1-butyl-3-metyl-imidazolium hexafluorophosphate (BMIPF6) has been studied using cyclic voltammetry, electrochemical impedance spectroscopy, immersion charge measurements and in situ scanning tunneling microscopy (in situ STM).
Collapse
Affiliation(s)
- C. Müller
- Institute of Electrochemistry
- Ulm University
- Albert-Einstein-Allee 47
- Ulm D-89069
- Germany
| | - K. Németh
- Institute for Solid State Physics and Optics
- Wigner Research Centre for Physics
- Hungarian Academy of Sciences
- H–1121 Budapest
- Hungary
| | | | - T. Pajkossy
- Institute of Materials and Environmental Chemistry
- Research Centre for Natural Sciences
- Hungarian Academy of Sciences
- H-1117 Budapest
- Hungary
| | - T. Jacob
- Institute of Electrochemistry
- Ulm University
- Albert-Einstein-Allee 47
- Ulm D-89069
- Germany
| |
Collapse
|
43
|
Liu X, Wang Y, Li S, Yan T. Effects of anion on the electric double layer of imidazolium-based ionic liquids on graphite electrode by molecular dynamics simulation. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.10.064] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
44
|
Bozym DJ, Uralcan B, Limmer DT, Pope MA, Szamreta NJ, Debenedetti PG, Aksay IA. Anomalous Capacitance Maximum of the Glassy Carbon-Ionic Liquid Interface through Dilution with Organic Solvents. J Phys Chem Lett 2015; 6:2644-2648. [PMID: 26266747 DOI: 10.1021/acs.jpclett.5b00899] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We use electrochemical impedance spectroscopy to measure the effect of diluting a hydrophobic room temperature ionic liquid with miscible organic solvents on the differential capacitance of the glassy carbon-electrolyte interface. We show that the minimum differential capacitance increases with dilution and reaches a maximum value at ionic liquid contents near 5-10 mol% (i.e., ∼1 M). We provide evidence that mixtures with 1,2-dichloroethane, a low-dielectric constant solvent, yield the largest gains in capacitance near the open circuit potential when compared against two traditional solvents, acetonitrile and propylene carbonate. To provide a fundamental basis for these observations, we use a coarse-grained model to relate structural variations at the double layer to the occurrence of the maximum. Our results reveal the potential for the enhancement of double-layer capacitance through dilution.
Collapse
Affiliation(s)
- David J Bozym
- †Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Betül Uralcan
- †Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - David T Limmer
- ‡Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08540, United States
| | - Michael A Pope
- †Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Nicholas J Szamreta
- †Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Pablo G Debenedetti
- †Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Ilhan A Aksay
- †Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| |
Collapse
|
45
|
Zeiger M, Weingarth D, Presser V. Quinone-Decorated Onion-Like Carbon/Carbon Fiber Hybrid Electrodes for High-Rate Supercapacitor Applications. ChemElectroChem 2015. [DOI: 10.1002/celc.201500130] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
46
|
Uysal A, Zhou H, Feng G, Lee SS, Li S, Cummings PT, Fulvio PF, Dai S, McDonough JK, Gogotsi Y, Fenter P. Interfacial ionic 'liquids': connecting static and dynamic structures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:032101. [PMID: 25475119 DOI: 10.1088/0953-8984/27/3/032101] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
It is well known that room temperature ionic liquids (RTILs) often adopt a charge-separated layered structure, i.e. with alternating cation- and anion-rich layers, at electrified interfaces. However, the dynamic response of the layered structure to temporal variations in applied potential is not well understood. We used in situ, real-time x-ray reflectivity to study the potential-dependent electric double layer (EDL) structure of an imidazolium-based RTIL on charged epitaxial graphene during potential cycling as a function of temperature. The results suggest that the graphene-RTIL interfacial structure is bistable in which the EDL structure at any intermediate potential can be described by the combination of two extreme-potential structures whose proportions vary depending on the polarity and magnitude of the applied potential. This picture is supported by the EDL structures obtained by fully atomistic molecular dynamics simulations at various static potentials. The potential-driven transition between the two structures is characterized by an increasing width but with an approximately fixed hysteresis magnitude as a function of temperature. The results are consistent with the coexistence of distinct anion- and cation-adsorbed structures separated by an energy barrier (∼0.15 eV).
Collapse
Affiliation(s)
- Ahmet Uysal
- Chemical Science and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Jin W, Liu X, Han Y, Li S, Yan T. Effects of repulsive interaction on the electric double layer of an imidazolium-based ionic liquid by molecular dynamics simulation. Phys Chem Chem Phys 2015; 17:2628-33. [DOI: 10.1039/c4cp04853a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Effects of repulsion between BMIM+/PF6− and the graphite electrode on electric double layer was studied by molecular dynamics simulation.
Collapse
Affiliation(s)
- Wenyang Jin
- Tianjin Key Laboratory of Metal- and Molecular-Based Material Chemistry
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)
- Institute of New Energy Material Chemistry
- College of Chemistry
| | - Xiaohong Liu
- Tianjin Key Laboratory of Metal- and Molecular-Based Material Chemistry
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)
- Institute of New Energy Material Chemistry
- College of Chemistry
| | - Yining Han
- Tianjin Key Laboratory of Metal- and Molecular-Based Material Chemistry
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)
- Institute of New Energy Material Chemistry
- College of Chemistry
| | - Shu Li
- Tianjin Key Laboratory of Metal- and Molecular-Based Material Chemistry
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)
- Institute of New Energy Material Chemistry
- College of Chemistry
| | - Tianying Yan
- Tianjin Key Laboratory of Metal- and Molecular-Based Material Chemistry
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)
- Institute of New Energy Material Chemistry
- College of Chemistry
| |
Collapse
|
48
|
Liu X, Han Y, Yan T. Temperature Effects on the Capacitance of an Imidazolium-based Ionic Liquid on a Graphite Electrode: A Molecular Dynamics Simulation. Chemphyschem 2014; 15:2503-9. [DOI: 10.1002/cphc.201402220] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Indexed: 11/06/2022]
|
49
|
Affiliation(s)
- Maxim V Fedorov
- Department of Physics, Scottish University Physics Alliance (SUPA), University of Strathclyde , John Anderson Bldg, 107 Rottenrow, Glasgow, G4 0NG United Kingdom
| | | |
Collapse
|