1
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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]
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2
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Wu J. Understanding the Electric Double-Layer Structure, Capacitance, and Charging Dynamics. Chem Rev 2022; 122:10821-10859. [PMID: 35594506 DOI: 10.1021/acs.chemrev.2c00097] [Citation(s) in RCA: 130] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Significant progress has been made in recent years in theoretical modeling of the electric double layer (EDL), a key concept in electrochemistry important for energy storage, electrocatalysis, and multitudes of other technological applications. However, major challenges remain in understanding the microscopic details of the electrochemical interface and charging mechanisms under realistic conditions. This review delves into theoretical methods to describe the equilibrium and dynamic responses of the EDL structure and capacitance for electrochemical systems commonly deployed for capacitive energy storage. Special emphasis is given to recent advances that intend to capture the nonclassical EDL behavior such as oscillatory ion distributions, polarization of nonmetallic electrodes, charge transfer, and various forms of phase transitions in the micropores of electrodes interfacing with an organic electrolyte or ionic liquid. This comprehensive analysis highlights theoretical insights into predictable relationships between materials characteristics and electrochemical performance and offers a perspective on opportunities for further development toward rational design and optimization of electrochemical systems.
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Affiliation(s)
- Jianzhong Wu
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
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3
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Qing L, Jiang J. Double-Edged Sword of Ion-Size Asymmetry in Energy Storage of Supercapacitors. J Phys Chem Lett 2022; 13:1438-1445. [PMID: 35129327 DOI: 10.1021/acs.jpclett.1c03900] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The advanced supercapacitor is of great significance for renewable energy storage. Achieving its high energy and high power densities remains a huge challenge. Herein, the contribution of ion-size asymmetry to the charging behavior of a supercapacitor is systematically studied using time-dependent density functional theory (TDDFT). We track the time evolution of the ionic microstructure inside the porous electrode and its reservoir and reveal a kinetic charge inversion in the asymmetrical ion-size cases. Compared with the symmetrical ion-size case, we find that the ion-size asymmetry has a double-edged sword effect on the energy storage of a supercapacitor: it accelerates the charging process yet reduces the differential capacitance. Additionally, the energy density and power density can simultaneously increase in the asymmetrical cases, which provides important insights toward the experimental design of supercapacitors with high energy and high power densities.
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Affiliation(s)
- Leying Qing
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Jian Jiang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
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4
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Verkholyak T, Kuzmak A, Kondrat S. Capacitive energy storage in single-file pores: Exactly solvable models and simulations. J Chem Phys 2021; 155:174112. [PMID: 34742202 DOI: 10.1063/5.0066786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Understanding charge storage in low-dimensional electrodes is crucial for developing novel ecologically friendly devices for capacitive energy storage and conversion and water desalination. Exactly solvable models allow in-depth analyses and essential physical insights into the charging mechanisms. So far, however, such analytical approaches have been mainly limited to lattice models. Herein, we develop a versatile, exactly solvable, one-dimensional off-lattice model for charging single-file pores. Unlike the lattice model, this model shows an excellent quantitative agreement with three-dimensional Monte Carlo simulations. With analytical calculations and simulations, we show that the differential capacitance can be bell-shaped (one peak), camel-shaped (two peaks), or have four peaks. Transformations between these capacitance shapes can be induced by changing pore ionophilicity, by changing cation-anion size asymmetry, or by adding solvent. We find that the camel-shaped capacitance, characteristic of dilute electrolytes, appears for strongly ionophilic pores with high ion densities, which we relate to charging mechanisms specific to narrow pores. We also derive a large-voltage asymptotic expression for the capacitance, showing that the capacitance decays to zero as the inverse square of the voltage, C ∼ u-2. This dependence follows from hard-core interactions and is not captured by the lattice model.
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Affiliation(s)
- Taras Verkholyak
- Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, Svientsitskii Street 1, 79011 Lviv, Ukraine
| | - Andrij Kuzmak
- Department for Theoretical Physics, I. Franko National University of Lviv, Lviv, Ukraine
| | - Svyatoslav Kondrat
- Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
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5
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Lee C, Yokoyama Y, Kondo Y, Miyahara Y, Abe T, Miyazaki K. Stabilizing the Nanosurface of LiNiO 2 Electrodes by Varying the Electrolyte Concentration: Correlation with Initial Electrochemical Behaviors for Use in Aqueous Li-Ion Batteries. ACS APPLIED MATERIALS & INTERFACES 2021; 13:44284-44293. [PMID: 34516104 DOI: 10.1021/acsami.1c11203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
This study attempted to stabilize the nanosurface of LiNiO2 (LNO) electrodes by varying the electrolyte concentration, significantly influencing its initial electrochemical behaviors for use in aqueous lithium-ion batteries. The charge/discharge capacities, reversibility, and cyclability of LNO were improved during initial cycles with an increase in the concentration of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). As determined by the galvanostatic intermittent titration technique, the superior diffusivity of Li+ ions in the LNO electrode is also obtained in the concentrated electrolyte. Nanoscale observation of the LNO surface revealed that its morphology is maintained relatively well in the concentrated electrolyte while it is destroyed in dilute electrolytes after the initial electrochemical cycles. These results are considered to be attributable to the variation of the interface condition in the electrical double layer with an increase in the electrolyte concentration, thus stabilizing the nanosurface of LNO by suppressing the dissolution of Ni ions from the surface. Additionally, in situ X-ray diffraction analysis demonstrated that LNO shows more stable phase transitions and volume changes as the electrolyte concentration increases, indicating that its structural changes in bulk can be directly related to the state of the nanosurface, which has a positive impact on the initial electrochemical behaviors in this system.
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Affiliation(s)
- Changhee Lee
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yuko Yokoyama
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yasuyuki Kondo
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yuto Miyahara
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Takeshi Abe
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kohei Miyazaki
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
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6
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Cruz C, Kondrat S, Lomba E, Ciach A. Capillary Ionization and Jumps of Capacitive Energy Stored in Mesopores. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:10243-10249. [PMID: 34276858 PMCID: PMC8282200 DOI: 10.1021/acs.jpcc.1c00624] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/21/2021] [Indexed: 05/26/2023]
Abstract
We study ionic liquid-solvent mixtures in slit-shaped nanopores wider than a few ion diameters. Using a continuum theory and generic thermodynamic reasoning, we reveal that such systems can undergo a capillary ionization transition. At this transition, the pores spontaneously ionize or deionize upon infinitesimal changes of temperature, slit width, or voltage. Our calculations show that a voltage applied to a pore may induce a capillary ionization, which-counterintuitively-is followed by a re-entrant deionization as the voltage increases. We find that such ionization transitions produce sharp jumps in the accumulated charge and stored energy, which may find useful applications in energy storage and heat-to-energy conversion.
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Affiliation(s)
- Carolina Cruz
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 44/52, 01-224 Warsaw, Poland
| | - Svyatoslav Kondrat
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 44/52, 01-224 Warsaw, Poland
- Max-Planck-Institut
für Intelligente Systeme, Heisenbergstraße 3, D-70569 Stuttgart, Germany
- IV.
Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - Enrique Lomba
- Instituto
de Química Física Rocasolano, CSIC, Serrano 119, E-28006 Madrid, Spain
| | - Alina Ciach
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 44/52, 01-224 Warsaw, Poland
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7
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Qing L, Zhao S, Wang ZG. Surface Charge Density in Electrical Double Layer Capacitors with Nanoscale Cathode-Anode Separation. J Phys Chem B 2021; 125:625-636. [PMID: 33405923 DOI: 10.1021/acs.jpcb.0c09332] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Using a dynamic density functional theory, we study the charging dynamics, the final equilibrium structure, and the energy storage in an electrical double layer capacitor with nanoscale cathode-anode separation in a slit geometry. We derive a simple expression for the surface charge density that naturally separates the effects of the charge polarization due to the ions from those due to the polarization of the dielectric medium and allows a more intuitive understanding of how the ion distribution within the cell affects the surface charge density. We find that charge neutrality in the half-cell does not hold during the dynamic charging process for any cathode-anode separation, and also does not hold at the final equilibrium state for small separations. Therefore, the charge accumulation in the half-cell in general does not equal the surface charge density. The relationships between the surface charge density and the charge accumulation within the half-cell are systematically investigated by tuning the electrolyte concentration, cathode-anode separation, and applied voltage. For high electrolyte concentrations, we observe charge inversion at which the charge accumulation exceeds the surface charge at special values of the separation. In addition, we find that the energy density has a maximum at intermediate electrolyte concentrations for a high applied voltage.
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Affiliation(s)
- Leying Qing
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China.,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Shuangliang Zhao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China.,Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology and School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Zhen-Gang Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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8
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Islam MS, Lamperski S, Islam MM, Henderson D, Bhuiyan LB. Temperature dependence of differential capacitance in the electric double layer.Symmetric valency 1:1 electrolytes. J Chem Phys 2020; 152:204702. [PMID: 32486666 DOI: 10.1063/5.0005966] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The differential capacitance of an electric double layer formed by an aqueous solution of KNO3 on a glassy carbon electrode is measured by impedance analysis at constant frequency. Results are obtained at electrolyte concentrations of 0.1 mol/dm3, 0.5 mol/dm3, and 1.0 mol/dm3, and at a series of temperatures, viz., 288 K, 298 K, 308 K, 318 K, and 328 K. The differential capacitance envelopes reveal a rich, complex pattern of maxima, minima, and local minima, whose magnitude and position change with a change in solution concentration. At the two lower concentrations, the temperature dependence of the capacitance, for example, at zero electrode potential, shows an alternating positive-negative behavior, while at the highest concentration of 1.0 mol/dm3, the slope of the differential capacitance-electrode potential curve is always positive. The experimental results are supplemented by a numerical grand canonical Monte Carlo simulation study of a restricted primitive model double layer but with an off-center cationic charge achieved by displacing the charge center from the ion sphere center toward its surface. The simulations, performed at the electrolyte concentration of 1.0 mol/dm3 and constant cation charge center displacement, and at varying electrode potentials and temperatures, show, in general, a negative temperature dependence of the differential capacitance. However, this temperature dependence can also be positive for a negative electrode charge and for a sufficiently large gradient of the cation charge center displacement with temperature. This feature is seen to be associated with an increase in the entropy of formation of the double layer.
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Affiliation(s)
- Md Siful Islam
- Department of Chemistry, University of Dhaka, Dhaka 1000, Bangladesh
| | - Stanisław Lamperski
- Department of Physical Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
| | - Md Mominul Islam
- Department of Chemistry, University of Dhaka, Dhaka 1000, Bangladesh
| | - Douglas Henderson
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-5700, USA
| | - Lutful Bari Bhuiyan
- Laboratory of Theoretical Physics, Department of Physics, University of Puerto Rico, 17 University Avenue, Suite 1701, San Juan, Puerto Rico 00925-2537, USA
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9
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Matse M, Berg P, Eikerling M. Asymmetric double-layer charging in a cylindrical nanopore under closed confinement. J Chem Phys 2020; 152:084103. [PMID: 32113335 DOI: 10.1063/1.5139541] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This article presents a physical-mathematical treatment and numerical simulations of electric double layer charging in a closed, finite, and cylindrical nanopore of circular cross section, embedded in a polymeric host with charged walls and sealed at both ends by metal electrodes under an external voltage bias. Modified Poisson-Nernst-Planck equations were used to account for finite ion sizes, subject to an electroneutrality condition. The time evolution of the formation and relaxation of the double layers was explored. Moreover, equilibrium ion distributions and differential capacitance curves were investigated as functions of the pore surface charge density, electrolyte concentration, ion sizes, and pore size. Asymmetric properties of the differential capacitance curves reveal that the structure of the double layer near each electrode is controlled by the charge concentration along the pore surface and by charge asymmetry in the electrolyte. These results carry implications for accurately simulating cylindrical capacitors and electroactuators.
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Affiliation(s)
- Mpumelelo Matse
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Peter Berg
- Department of Science, University of Alberta, Camrose, Alberta T4V 2R3, Canada
| | - Michael Eikerling
- Department of Physics and Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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10
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Sharma S, Dhattarwal HS, Kashyap HK. Molecular dynamics investigation of electrostatic properties of pyrrolidinium cation based ionic liquids near electrified carbon electrodes. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111269] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Gallegos A, Lian C, Dyatkin B, Wu J. Side-chain effects on the capacitive behaviour of ionic liquids in microporous electrodes. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1650210] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Alejandro Gallegos
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, USA
| | - Cheng Lian
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, PR People’s Republic of China
| | - Boris Dyatkin
- A.J. Drexel Nanomaterials Institute and the Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA
| | - Jianzhong Wu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, USA
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12
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Ma K, Forsman J, Woodward CE. Theoretical study of the effect of π^{+}-π^{+} association in imidazolium ionic liquids at charged interfaces. Phys Rev E 2018; 96:062609. [PMID: 29347444 DOI: 10.1103/physreve.96.062609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Indexed: 11/07/2022]
Abstract
We develop an extended classical density-functional theory to describe clustering of imidazolium-based cations into linear chains, driven by π-π stacking. We find that the associating system displays a similar short-ranged structure to the completely dissociated fluid. We also construct a restricted primitive model for associating ionic species in an RTIL+solvent mixture. The double-layer formed in these systems exhibits strong overscreening by the cation chains, as expected. Significantly enhanced capacitance is also observed for the case where counterions are the associating species. The established density-functional method can be also used to describe polydisperse polyelectrolyte models.
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Affiliation(s)
- Ke Ma
- School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, P. R. China and Tianjin Key Laboratory for Photoelectric Materials and Devices, Tianjin University of Technology, Tianjin 300384, China
| | - Jan Forsman
- Theoretical Chemistry, Chemical Centre, Lund University, P. O. Box 124, S-221 00 Lund, Sweden
| | - Clifford E Woodward
- School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Canberra at the Australian Defence Force Academy, Canberra ACT 2600, Australia
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13
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The effect of dispersion interactions on the structure and performance of electrical double layer of ionic liquids. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.09.077] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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14
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Yang H, Yang J, Bo Z, Chen X, Shuai X, Kong J, Yan J, Cen K. Kinetic-Dominated Charging Mechanism within Representative Aqueous Electrolyte-based Electric Double-Layer Capacitors. J Phys Chem Lett 2017; 8:3703-3710. [PMID: 28742361 DOI: 10.1021/acs.jpclett.7b01525] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The chemical nature of electrolytes has been demonstrated to play a pivotal role in the charge storage of electric double-layer capacitors (EDLCs), whereas primary mechanisms are still partially resolved but controversial. In this work, a systematic exploration into EDL structures and kinetics of representative aqueous electrolytes is performed with numerical simulation and experimental research. Unusually, a novel charging mechanism exclusively predominated by kinetics is recognized, going beyond traditional views of manipulating capacitances preferentially via interfacial structural variations. Specifically, strikingly distinctive EDL structures stimulated by diverse ion sizes, valences, and mixtures manifest a virtually identical EDL capacitance, where the dielectric nature of solvents attenuates ionic effects on electrolyte redistributions, in stark contradiction with solvent-free counterpart and traditional Helmholtz theory. Meanwhile, corresponding kinetics evolve conspicuously with ionic species, intimately correlated with ion-solvent interactions. The achieved mechanisms are subsequently illuminated by electrochemical measurements, highlighting the crucial interplay between ions and solvents in regulating EDLC performances.
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Affiliation(s)
- Huachao Yang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
| | - Jinyuan Yang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
| | - Zheng Bo
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
| | - Xia Chen
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
| | - Xiaorui Shuai
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
| | - Jing Kong
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
| | - Jianhua Yan
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
| | - Kefa Cen
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University , Hangzhou, Zhejiang Province 310027, China
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15
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Silvestre-Alcantara W, Henderson D, Wu J, Kaja M, Lamperski S, Bhuiyan LB. Structure of an electric double layer containing a 2:2 valency dimer electrolyte. J Colloid Interface Sci 2015; 449:175-9. [PMID: 25529333 DOI: 10.1016/j.jcis.2014.11.070] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 11/24/2014] [Accepted: 11/25/2014] [Indexed: 11/19/2022]
Abstract
The structure of a planar electric double layer formed by a 2:2 valency dimer electrolyte in the vicinity of a uniformly charged planar hard electrode is investigated using density functional theory and Monte Carlo simulations. The dimer electrolyte consists of a mixture of charged divalent dimers and charged divalent monomers in a dielectric continuum. A dimer is constructed by two tangentially tethered rigid spheres, one of which is divalent and positively charged and the other neutral, whereas the monomer is a divalent and negatively charged rigid sphere. The density functional theory reproduces well the simulation results for (i) the singlet distributions of the various ion species with respect to the electrode, and (ii) the mean electrostatic potential. Comparison with earlier results for a 2:1/1:2 dimer electrolyte shows that the double layer structure is similar when the counterion has the same valency.
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Affiliation(s)
| | - Douglas Henderson
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602-5700, USA
| | - Jianzhong Wu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521-0425, USA
| | - Monika Kaja
- Department of Physical Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89b, 61-614 Poznań, Poland
| | - Stanisław Lamperski
- Department of Physical Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89b, 61-614 Poznań, Poland
| | - Lutful Bari Bhuiyan
- Laboratory of Theoretical Physics, Department of Physics, University of Puerto Rico, San Juan, PR 00936-8377, USA.
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16
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Vatamanu J, Vatamanu M, Bedrov D. Non-Faradaic Energy Storage by Room Temperature Ionic Liquids in Nanoporous Electrodes. ACS NANO 2015; 9:5999-6017. [PMID: 26038979 DOI: 10.1021/acsnano.5b00945] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The enhancement of non-Faradaic charge and energy density stored by ionic electrolytes in nanostructured electrodes is an intriguing issue of great practical importance for energy storage in electric double layer capacitors. On the basis of extensive molecular dynamics simulations of various carbon-based nanoporous electrodes and room temperature ionic liquid (RTIL) electrolytes, we identify atomistic mechanisms and correlations between electrode/electrolyte structures that lead to capacitance enhancement. In the symmetric electrode setup with nanopores having atomically smooth walls, most RTILs showed up to 50% capacitance increase compared to infinitely wide pore. Extensive simulations using asymmetric electrodes and pores with atomically rough surfaces demonstrated that tuning of electrode nanostructure could lead to further substantial capacitance enhancement. Therefore, the capacitance in nanoporous electrodes can be increased due to a combination of two effects: (i) the screening of ionic interactions by nanopore walls upon electrolyte nanoconfinement, and (ii) the optimization of nanopore structure (volume, surface roughness) to take into account the asymmetry between cation and anion chemical structures.
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Affiliation(s)
- Jenel Vatamanu
- Material Sciences and Engineering Department, University of Utah, 122 South Central Campus Drive, Salt Lake City, Utah 84112, United States
| | - Mihaela Vatamanu
- Material Sciences and Engineering Department, University of Utah, 122 South Central Campus Drive, Salt Lake City, Utah 84112, United States
| | - Dmitry Bedrov
- Material Sciences and Engineering Department, University of Utah, 122 South Central Campus Drive, Salt Lake City, Utah 84112, United States
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17
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Ratkova EL, Palmer DS, Fedorov MV. Solvation thermodynamics of organic molecules by the molecular integral equation theory: approaching chemical accuracy. Chem Rev 2015; 115:6312-56. [PMID: 26073187 DOI: 10.1021/cr5000283] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Ekaterina L Ratkova
- †G. A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Akademicheskaya Street 1, Ivanovo 153045, Russia.,‡The Max Planck Institute for Mathematics in the Sciences, Inselstrasse 22, Leipzig 04103, Germany
| | - David S Palmer
- ‡The Max Planck Institute for Mathematics in the Sciences, Inselstrasse 22, Leipzig 04103, Germany.,§Department of Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow, Scotland G1 1XL, United Kingdom
| | - Maxim V Fedorov
- ‡The Max Planck Institute for Mathematics in the Sciences, Inselstrasse 22, Leipzig 04103, Germany.,∥Department of Physics, Scottish Universities Physics Alliance (SUPA), University of Strathclyde, John Anderson Building, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
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18
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Affiliation(s)
- Robert Hayes
- Discipline
of Chemistry, The University of Newcastle, NSW 2308, Callaghan, Australia
| | - Gregory G. Warr
- School
of Chemistry, The University of Sydney, NSW 2006, Sydney, Australia
| | - Rob Atkin
- Discipline
of Chemistry, The University of Newcastle, NSW 2308, Callaghan, Australia
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19
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Ma K, Forsman J, Woodward CE. Influence of ion pairing in ionic liquids on electrical double layer structures and surface force using classical density functional approach. J Chem Phys 2015; 142:174704. [DOI: 10.1063/1.4919314] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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20
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Hu Z, Vatamanu J, Borodin O, Bedrov D. A comparative study of alkylimidazolium room temperature ionic liquids with FSI and TFSI anions near charged electrodes. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.08.072] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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21
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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
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22
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Jiang J, Cao D, Henderson D, Wu J. Revisiting density functionals for the primitive model of electric double layers. J Chem Phys 2014; 140:044714. [DOI: 10.1063/1.4862990] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lamperski S, Sosnowska J, Bhuiyan LB, Henderson D. Size asymmetric hard spheres as a convenient model for the capacitance of the electrical double layer of an ionic liquid. J Chem Phys 2014; 140:014704. [DOI: 10.1063/1.4851456] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Lamperski S, Kaja M, Bhuiyan LB, Wu J, Henderson D. Influence of anisotropic ion shape on structure and capacitance of an electric double layer: A Monte Carlo and density functional study. J Chem Phys 2013; 139:054703. [DOI: 10.1063/1.4817325] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pizio O, Sokołowski S. Restricted primitive model for electrolyte solutions in slit-like pores with grafted chains: Microscopic structure, thermodynamics of adsorption, and electric properties from a density functional approach. J Chem Phys 2013; 138:204715. [DOI: 10.1063/1.4807777] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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