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Ma L, Jiang J. Vehicular Motions Dominate the Ion Transport in Concentrated LiTFSI Aqueous Solutions? J Phys Chem Lett 2024; 15:4531-4537. [PMID: 38635898 DOI: 10.1021/acs.jpclett.4c00791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Water-in-salt electrolytes (WiSEs) show great promise for applications in grid-scale energy storage. The design of high-performance WiSEs requires a comprehensive understanding of their microstructures and ion transport properties. In the present work, based on the CL&Pol force field, we have developed a polarizable force field (PFF) tailored for high-concentration LiTFSI aqueous solutions, which accurately reproduces the structural and dynamical properties. Unlike the literature, we do not observe the presence of bulk-like water in LiTFSI solutions exceeding 19 mol/kg. Furthermore, we find that the vast majority of Li(H20)n+ are short-lived, and thus, the structural motion rather than the vehicular motion is the main mode of ion transport. Our results have significant implications for understanding the ion dynamics in WiSEs. Additionally, further in-depth experimental analyses are imperative.
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Affiliation(s)
- Linbo Ma
- 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
| | - 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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2
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Lyu X, Wang H, Liu X, He L, Do C, Seifert S, Winans RE, Cheng L, Li T. Solvation Structure of Methanol-in-Salt Electrolyte Revealed by Small-Angle X-ray Scattering and Simulations. ACS NANO 2024; 18:7037-7045. [PMID: 38373167 DOI: 10.1021/acsnano.3c10469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The solvation structure of water-in-salt electrolytes was thoroughly studied, and two competing structures─anion solvated structure and anion network─were well-defined in recent publications. To further reveal the solvation structure in those highly concentrated electrolytes, particularly the influence of solvent, methanol was chosen as the solvent for this proposed study. In this work, small-angle X-ray scattering, small-angle neutron scattering, Fourier-transform infrared spectroscopy, and Raman spectroscopy were utilized to obtain the global and local structural information. With the concentration increment, the anion network formed by TFSI- became the dominant structure. Meanwhile, the hydrogen bonds among methanol were interrupted by the TFSI- anion and formed a new connection with them. Molecular dynamic simulations with two different force fields (GAFF and OPLS-AA) are tested, and GAFF agreed with synchrotron small-angle X-ray scattering/wide-angle X-ray scattering (SAXS/WAXS) results well and provided insightful information about molecular/ion scale solvation structure. This article not only deepens the understanding of the solvation structure in highly concentrated solutions, but more importantly, it provides additional strong evidence for utilizing SAXS/WAXS to validate molecular dynamics simulations.
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Affiliation(s)
- Xingyi Lyu
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States
| | - Haimeng Wang
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Xinyi Liu
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States
| | - Lilin He
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Changwoo Do
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Soenke Seifert
- X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Randall E Winans
- X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Lei Cheng
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Tao Li
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States
- X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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3
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Kacenauskaite L, Van Wyck SJ, Moncada Cohen M, Fayer MD. Water-in-Salt: Fast Dynamics, Structure, Thermodynamics, and Bulk Properties. J Phys Chem B 2024; 128:291-302. [PMID: 38118403 DOI: 10.1021/acs.jpcb.3c07711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
We present concentration-dependent dynamics of highly concentrated LiBr solutions and LiCl temperature-dependent dynamics for two high concentrations and compare the results to those of prior LiCl concentration-dependent data. The dynamical data are obtained using ultrafast optical heterodyne-detected optical Kerr effect (OHD-OKE). The OHD-OKE decays are composed of two pairs of biexponentials, i.e., tetra-exponentials. The fastest decay (t1) is the same as pure water's at all concentrations within error, while the second component (t2) slows slightly with concentration. The slower components (t3 and t4), not present in pure water, slow substantially, and their contributions to the decays increase significantly with increasing concentration, similar to LiCl solutions. Simulations of LiCl solutions from the literature show that the slow components arise from large ion/water clusters, while the fast components are from ion/water structures that are not part of large clusters. Temperature-dependent studies (15-95 °C) of two high LiCl concentrations show that decreasing the temperature is equivalent to increasing the room temperature concentration. The LiBr and LiCl concentration dependences and the two LiCl concentrations' temperature dependences all have bulk viscosities that are linearly dependent on τcslow, the correlation time of the slow dynamics (weighted averages of t3 and t4). Remarkably, all four viscosity vs 1/τCslow plots fall on the same line. Application of transition state theory to the temperature-dependent data yields the activation enthalpies and entropies for the dynamics of the large ion/water clusters, which underpin the bulk viscosity.
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Affiliation(s)
- Laura Kacenauskaite
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Copenhagen 2100, Denmark
| | - Stephen J Van Wyck
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Max Moncada Cohen
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Michael D Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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4
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González MA, Akiba H, Borodin O, Cuello GJ, Hennet L, Kohara S, Maginn EJ, Mangin-Thro L, Yamamuro O, Zhang Y, Price DL, Saboungi ML. Structure of water-in-salt and water-in-bisalt electrolytes. Phys Chem Chem Phys 2022; 24:10727-10736. [PMID: 35451439 DOI: 10.1039/d2cp00537a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a systematic diffraction study of two "water-in-salt" electrolytes and a "water-in-bisalt" electrolyte combining high-energy X-ray diffraction (HEXRD) with polarized and unpolarized neutron diffraction (ND) on both H2O and D2O solutions. The measurements provide three independent combinations of correlations between the different pairs of atom types that reveal the short- and intermediate-range order in considerable detail. The ND interference functions show pronounced peaks around a scattering vector Q ∼ 0.5 Å-1 that change dramatically with composition, indicating significant rearrangements of the water network on a length scale around 12 Å. The experimental results are compared with two sets of Molecular Dynamics (MD) simulations, one including polarization effects and the other based on a non-polarizable force field. The two simulations reproduce the general shapes of the experimental structure factors and their changes with concentration, but differ in many detailed respects, suggesting ways in which their force fields might be modified to better represent the actual systems.
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Affiliation(s)
| | - Hiroshi Akiba
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Oleg Borodin
- Battery Science Branch, U.S. Army Combat Capabilities Development Command, Army Research Laboratory, Adelphi, Maryland 20783, USA.
| | | | - Louis Hennet
- ICMN, Université d'Orléans/CNRS, 45071 Orléans, France
| | - Shinji Kohara
- Research Center for Advanced Measurement and Characterization, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Edward J Maginn
- Dept. of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Lucile Mangin-Thro
- Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Osamu Yamamuro
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Yong Zhang
- Dept. of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.,Joint Center for Energy Storage Research, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - David L Price
- CEMHTI, CNRS/Université d'Orléans, 45071 Orléans, France
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5
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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: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [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.
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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
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6
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Zhai Y, Luo P, Waller J, Self JL, Harriger LW, Z Y, Faraone A. Dynamics of molecular associates in methanol/water mixtures. Phys Chem Chem Phys 2022; 24:2287-2299. [PMID: 35015001 DOI: 10.1039/d1cp04726d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dynamics of molecular associates in a methanol/water mixture was investigated using quasielastic neutron scattering. By measuring the signal from four methanol/water samples differing only by their isotopic composition, the relative motion of the water to methanol molecules, i.e. their mutual dynamics, was determined at the nanoscale. The thus obtained nanoscopic mutual diffusion coefficient signals a significantly slower process than the single particle diffusion of either methanol or water in the system as well as their macroscopic mutual diffusion. The data do not provide any indication of microsegregation in this preeminent alcohol/water mixture; however, they do indicate the existence of long lived but dynamic molecular associates of water and methanol molecules. Analysis of the structural relaxation shows that the lifetime of molecular association through hydrogen bonding determines the fact that viscosity of the mixtures at intermediate concentrations is higher than that of both pure components.
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Affiliation(s)
- Yanqin Zhai
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Peng Luo
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jackson Waller
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Jeffrey L Self
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - Leland W Harriger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
| | - Y Z
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Antonio Faraone
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
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7
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Zhang J, Wang F, Cao Z, Wang Q. New State-Diagram of Aqueous Solutions Unveiling Ionic Hydration, Antiplasticization, and Structural Heterogeneities in LiTFSI-H 2O. J Phys Chem B 2021; 125:13041-13048. [PMID: 34788045 DOI: 10.1021/acs.jpcb.1c08431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here, we report a new state-diagram for aqueous solutions based on concentration-dependent glass-transition temperatures of concentrated and ice freeze-concentrated solutions. Different from the equilibrium phase diagram, this new state-diagram can provide comprehensive information about the hydration numbers of solutes, nonequilibrium vitrification/cold-crystallization, and vitrification/devitrification processes of aqueous solutions in three distinct concentration zones separated by two critical water-content points of only functions of the hydration number. Based on this new state-diagram, we observe the comparable hydration ability of LiTFSI to LiCl and an atypical concentration-dependent cold-crystallization behavior of the LiTFSI-H2O system. These results unveil the negligible hydration ability of TFSI- in a water-rich solution, characterize the antiplasticizing effect of water induced by the strengthened Li+-TFSI--H2O interaction when only hydration water and confined water are present, and confirm the increasing fraction of water-rich domains with the decrease in water content when the cation and anion become incompletely hydrated on average. These results highlight the novel water-content-mediated interactions among the anion, cation, and H2O for LiTFSI-H2O.
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Affiliation(s)
- Jinbing Zhang
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fengping Wang
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Zexian Cao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Qiang Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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8
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Triolo A, Di Lisio V, Lo Celso F, Appetecchi GB, Fazio B, Chater P, Martinelli A, Sciubba F, Russina O. Liquid Structure of a Water-in-Salt Electrolyte with a Remarkably Asymmetric Anion. J Phys Chem B 2021; 125:12500-12517. [PMID: 34738812 PMCID: PMC9282637 DOI: 10.1021/acs.jpcb.1c06759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Water-in-salt
systems, i.e., super-concentrated aqueous electrolytes,
such as lithium bis(trifluoromethanesulfonyl)imide (21 mol/kgwater), have been recently discovered to exhibit unexpectedly
large electrochemical windows and high lithium transference numbers,
thus paving the way to safe and sustainable charge storage devices.
The peculiar transport features in these electrolytes are influenced
by their intrinsically nanoseparated morphology, stemming from the
anion hydrophobic nature and manifesting as nanosegregation between
anions and water domains. The underlying mechanism behind this structure–dynamics
correlation is, however, still a matter of strong debate. Here, we
enhance the apolar nature of the anions, exploring the properties
of the aqueous electrolytes of lithium salts with a strongly asymmetric
anion, namely, (trifluoromethylsulfonyl)(nonafluorobutylsulfonyl)
imide. Using a synergy of experimental and computational tools, we
detect a remarkable level of structural heterogeneity at a mesoscopic
level between anion-rich and water-rich domains. Such a ubiquitous
sponge-like, bicontinuous morphology develops across the whole concentration
range, evolving from large fluorinated globules at high dilution to
a percolating fluorous matrix intercalated by water nanowires at super-concentrated
regimes. Even at extremely concentrated conditions, a large population
of fully hydrated lithium ions, with no anion coordination, is detected.
One can then derive that the concomitant coexistence of (i) a mesoscopically
segregated structure and (ii) fully hydrated lithium clusters disentangled
from anion coordination enables the peculiar lithium diffusion features
that characterize water-in-salt systems.
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Affiliation(s)
- Alessandro Triolo
- Laboratorio Liquidi Ionici, Istituto Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), Rome 00133, Italy
| | - Valerio Di Lisio
- Department of Chemistry, University of Rome Sapienza, Rome 00185, Italy
| | - Fabrizio Lo Celso
- Laboratorio Liquidi Ionici, Istituto Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), Rome 00133, Italy.,Department of Physics and Chemistry, Università di Palermo, Palermo 90133, Italy
| | | | - Barbara Fazio
- Istituto Processi Chimico-Fisici, Consiglio Nazionale delle Ricerche (IPCF-CNR), Messina 98158, Italy
| | - Philip Chater
- Diamond House, Harwell Science & Innovation Campus, Diamond Light Source, Ltd., Didcot OX11 0DE, U.K
| | - Andrea Martinelli
- Department of Chemistry, University of Rome Sapienza, Rome 00185, Italy
| | - Fabio Sciubba
- Department of Chemistry, University of Rome Sapienza, Rome 00185, Italy.,NMR-Based Metabolomics Laboratory (NMLab), Sapienza University of Rome, Rome 00185, Italy
| | - Olga Russina
- Laboratorio Liquidi Ionici, Istituto Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), Rome 00133, Italy.,Department of Chemistry, University of Rome Sapienza, Rome 00185, Italy
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