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Markiewitz DM, Goodwin ZAH, McEldrew M, Pedro de Souza J, Zhang X, Espinosa-Marzal RM, Bazant MZ. Electric field induced associations in the double layer of salt-in-ionic-liquid electrolytes. Faraday Discuss 2024. [PMID: 39176453 DOI: 10.1039/d4fd00021h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
Ionic liquids (ILs) are an extremely exciting class of electrolytes for energy storage applications. Upon dissolving alkali metal salts, such as Li or Na based salts, with the same anion as the IL, an intrinsically asymmetric electrolyte can be created for use in batteries, known as a salt-in-ionic liquid (SiIL). These SiILs have been well studied in the bulk, where negative transference numbers of the alkali metal cation have been observed from the formation of small, negatively charged clusters. The properties of these SiILs at electrified interfaces, however, have received little to no attention. Here, we develop a theory for the electrical double layer (EDL) of SiILs where we consistently account for the thermoreversible association of ions into Cayley tree aggregates. The theory predicts that the IL cations first populate the EDL at negative voltages, as they are not strongly bound to the anions. However, at large negative voltages, which are strong enough to break the alkali metal cation-anion associations, these IL cations are exchanged for the alkali metal cation because of their higher charge density. At positive voltages, we find that the SiIL actually becomes more aggregated while screening the electrode charge from the formation of large, negatively charged aggregates. Therefore, in contrast to conventional intuition of associations in the EDL, SiILs appear to become more associated in certain electric fields. We present these theoretical predictions to be verified by molecular dynamics simulations and experimental measurements.
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Affiliation(s)
- Daniel M Markiewitz
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
| | - Zachary A H Goodwin
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Michael McEldrew
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
| | - J Pedro de Souza
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
- Omenn-Darling Bioengineering Institute, Princeton University, Princeton, New Jersey 08544, USA
| | - Xuhui Zhang
- Department of Civil and Environmental Engineering, University of Illinois at Urbana - Champaign, Urbana, IL, 61801, USA
| | - Rosa M Espinosa-Marzal
- Department of Civil and Environmental Engineering, University of Illinois at Urbana - Champaign, Urbana, IL, 61801, USA
- Department of Materials Science and Engineering, University of Illinois at Urbana - Champaign, Urbana, IL, 61801, USA
| | - Martin Z Bazant
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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2
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Härtel A, Bültmann M, Coupette F. Anomalous Underscreening in the Restricted Primitive Model. PHYSICAL REVIEW LETTERS 2023; 130:108202. [PMID: 36962045 DOI: 10.1103/physrevlett.130.108202] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/19/2022] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
Underscreening is a collective term for charge correlations in electrolytes decaying slower than the Debye length. Anomalous underscreening refers to phenomenology that cannot be attributed alone to steric interactions. Experiments with concentrated electrolytes and ionic fluids report anomalous underscreening, which so far has not been observed in simulation. We present Molecular Dynamics simulation results exhibiting anomalous underscreening that can be connected to cluster formation. A theory that accounts for ion pairing confirms the trend. Our results challenge the classic understanding of dense electrolytes impacting the design of technologies for energy storage and conversion.
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Affiliation(s)
- Andreas Härtel
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Moritz Bültmann
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Fabian Coupette
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
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3
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Gregory KP, Elliott GR, Robertson H, Kumar A, Wanless EJ, Webber GB, Craig VSJ, Andersson GG, Page AJ. Understanding specific ion effects and the Hofmeister series. Phys Chem Chem Phys 2022; 24:12682-12718. [PMID: 35543205 DOI: 10.1039/d2cp00847e] [Citation(s) in RCA: 87] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Specific ion effects (SIE), encompassing the Hofmeister Series, have been known for more than 130 years since Hofmeister and Lewith's foundational work. SIEs are ubiquitous and are observed across the medical, biological, chemical and industrial sciences. Nevertheless, no general predictive theory has yet been able to explain ion specificity across these fields; it remains impossible to predict when, how, and to what magnitude, a SIE will be observed. In part, this is due to the complexity of real systems in which ions, counterions, solvents and cosolutes all play varying roles, which give rise to anomalies and reversals in anticipated SIEs. Herein we review the historical explanations for SIE in water and the key ion properties that have been attributed to them. Systems where the Hofmeister series is perturbed or reversed are explored, as is the behaviour of ions at the liquid-vapour interface. We discuss SIEs in mixed electrolytes, nonaqueous solvents, and in highly concentrated electrolyte solutions - exciting frontiers in this field with particular relevance to biological and electrochemical applications. We conclude the perspective by summarising the challenges and opportunities facing this SIE research that highlight potential pathways towards a general predictive theory of SIE.
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Affiliation(s)
- Kasimir P Gregory
- Discipline of Chemistry, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia. .,Department of Materials Physics, Research School of Physics, Australian National University, Canberra, ACT 0200, Australia
| | - Gareth R Elliott
- Discipline of Chemistry, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia.
| | - Hayden Robertson
- Discipline of Chemistry, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia.
| | - Anand Kumar
- Flinders Institute of Nanoscale Science and Technology, College of Science and Engineering, Flinders University, South Australia 5001, Australia
| | - Erica J Wanless
- Discipline of Chemistry, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia.
| | - Grant B Webber
- School of Engineering, The University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Vincent S J Craig
- Department of Materials Physics, Research School of Physics, Australian National University, Canberra, ACT 0200, Australia
| | - Gunther G Andersson
- Flinders Institute of Nanoscale Science and Technology, College of Science and Engineering, Flinders University, South Australia 5001, Australia
| | - Alister J Page
- Discipline of Chemistry, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia.
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4
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Rickert CA, Lieleg O. Machine learning approaches for biomolecular, biophysical, and biomaterials research. BIOPHYSICS REVIEWS 2022; 3:021306. [PMID: 38505413 PMCID: PMC10914139 DOI: 10.1063/5.0082179] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 05/12/2022] [Indexed: 03/21/2024]
Abstract
A fluent conversation with a virtual assistant, person-tailored news feeds, and deep-fake images created within seconds-all those things that have been unthinkable for a long time are now a part of our everyday lives. What these examples have in common is that they are realized by different means of machine learning (ML), a technology that has fundamentally changed many aspects of the modern world. The possibility to process enormous amount of data in multi-hierarchical, digital constructs has paved the way not only for creating intelligent systems but also for obtaining surprising new insight into many scientific problems. However, in the different areas of biosciences, which typically rely heavily on the collection of time-consuming experimental data, applying ML methods is a bit more challenging: Here, difficulties can arise from small datasets and the inherent, broad variability, and complexity associated with studying biological objects and phenomena. In this Review, we give an overview of commonly used ML algorithms (which are often referred to as "machines") and learning strategies as well as their applications in different bio-disciplines such as molecular biology, drug development, biophysics, and biomaterials science. We highlight how selected research questions from those fields were successfully translated into machine readable formats, discuss typical problems that can arise in this context, and provide an overview of how to resolve those encountered difficulties.
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5
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Yuan H, Deng W, Zhu X, Liu G, Craig VSJ. Colloidal Systems in Concentrated Electrolyte Solutions Exhibit Re-entrant Long-Range Electrostatic Interactions due to Underscreening. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:6164-6173. [PMID: 35512818 PMCID: PMC9119301 DOI: 10.1021/acs.langmuir.2c00519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/26/2022] [Indexed: 05/07/2023]
Abstract
Surface force measurements have revealed that at very high electrolyte concentrations as well as in neat and diluted ionic liquids and deep eutectic solvents, the range of electrostatic interactions is far greater than the Debye length. Here, we explore the consequences of this underscreening for soft-matter and colloidal systems by investigating the stability of nanoparticle dispersions, the self-assembly of ionic surfactants, and the thickness of soap films. In each case, we find clear evidence of re-entrant properties due to underscreening at high salt concentrations. Our results show that underscreening in concentrated electrolytes is a general phenomenon and is not dependent on confinement by macroscopic surfaces. The stability of systems at very high salinity due to underscreening may be beneficially applied to processes that currently use low-salinity water.
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Affiliation(s)
- Haiyang Yuan
- Department
of Chemical Physics, Key Laboratory of Surface and Interface Chemistry
and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Wenjie Deng
- Department
of Chemical Physics, Key Laboratory of Surface and Interface Chemistry
and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xiaolong Zhu
- State
Key Laboratory of Fire Science, University
of Science and Technology of China, Hefei 230026, P. R. China
| | - Guangming Liu
- Department
of Chemical Physics, Key Laboratory of Surface and Interface Chemistry
and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Vincent Stuart James Craig
- Department
of Chemical Physics, Key Laboratory of Surface and Interface Chemistry
and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230026, P. R. China
- Department
of Applied Mathematics, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
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6
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Dean JM, Coles SW, Saunders WR, McCluskey AR, Wolf MJ, Walker AB, Morgan BJ. Overscreening and Underscreening in Solid-Electrolyte Grain Boundary Space-Charge Layers. PHYSICAL REVIEW LETTERS 2021; 127:135502. [PMID: 34623837 DOI: 10.1103/physrevlett.127.135502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Polycrystalline solids can exhibit material properties that differ significantly from those of equivalent single-crystal samples, in part, because of a spontaneous redistribution of mobile point defects into so-called space-charge regions adjacent to grain boundaries. The general analytical form of these space-charge regions is known only in the dilute limit, where defect-defect correlations can be neglected. Using kinetic Monte Carlo simulations of a three-dimensional Coulomb lattice gas, we show that grain boundary space-charge regions in nondilute solid electrolytes exhibit overscreening-damped oscillatory space-charge profiles-and underscreening-decay lengths that are longer than the corresponding Debye length and that increase with increasing defect-defect interaction strength. Overscreening and underscreening are known phenomena in concentrated liquid electrolytes, and the observation of functionally analogous behavior in solid electrolyte space-charge regions suggests that the same underlying physics drives behavior in both classes of systems. We therefore expect theoretical approaches developed to study nondilute liquid electrolytes to be equally applicable to future studies of solid electrolytes.
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Affiliation(s)
- Jacob M Dean
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, United Kingdom
| | - Samuel W Coles
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, United Kingdom
| | - William R Saunders
- Department of Physics, University of Bath, Claverton Down BA2 7AY, United Kingdom
| | - Andrew R McCluskey
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- European Spallation Source ERIC, P.O. Box 176, SE-221 00, Lund, Sweden
| | - Matthew J Wolf
- Department of Physics, University of Bath, Claverton Down BA2 7AY, United Kingdom
| | - Alison B Walker
- Department of Physics, University of Bath, Claverton Down BA2 7AY, United Kingdom
| | - Benjamin J Morgan
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, United Kingdom
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7
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Fong KD, Self J, McCloskey BD, Persson KA. Ion Correlations and Their Impact on Transport in Polymer-Based Electrolytes. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02545] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Kara D. Fong
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Julian Self
- Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Bryan D. McCloskey
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Kristin A. Persson
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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