1
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Wood HO, Burnett HM, Dryfe RAW, Carbone P. Stability and structure of the aqueous LiTFSI-LiCl interface. Faraday Discuss 2024. [PMID: 39023276 DOI: 10.1039/d4fd00026a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
It has recently been demonstrated that aqueous lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium chloride (LiCl) solutions can form stable liquid-liquid biphasic systems when both electrolyte phases have sufficiently high concentrations. In this work, we combine molecular dynamics simulations and experimental analysis to investigate what drives the formation of the interface and how the interfacial molecular structure correlates with its thermodynamic stability. We observe that at the liquid-vapour interface, TFSI- anions exhibit surfactant-like properties, leading to a reduction in surface tension and an increase in interfacial thickness. In contrast, the interfacial stability of the LiTFSI-LiCl biphasic systems increases with the concentration of both salts, as evidenced by the increasing surface tension and decreasing interfacial thickness. The opposing effects that the ionic concentration has on the thermodynamic stability of the different interfaces are linked to the anions' interfacial adsorption/desorption, which in turn affects the number and strength of water-water hydrogen bonds, the interfacial molecular structure and the diffusion of cations across the interface. Finally, calculations and experiments indicate that the liquid-liquid separation is driven primarily by the concentration of LiCl, and is the result of a 'salting out' effect.
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Affiliation(s)
- Hannah O Wood
- Department of Chemistry, University of Manchester, Oxford Rd, Manchester, UK.
| | - Hannah M Burnett
- Department of Chemistry, University of Manchester, Oxford Rd, Manchester, UK.
| | - Robert A W Dryfe
- Department of Chemistry, University of Manchester, Oxford Rd, Manchester, UK.
| | - Paola Carbone
- Department of Chemistry, University of Manchester, Oxford Rd, Manchester, UK.
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2
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Bi S, Salanne M. Cluster analysis as a tool for quantifying structure-transport properties in simulations of superconcentrated electrolyte. Chem Sci 2024; 15:10908-10917. [PMID: 39027304 PMCID: PMC11253178 DOI: 10.1039/d4sc01491j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 06/09/2024] [Indexed: 07/20/2024] Open
Abstract
Using molecular dynamics simulations and graph-theory-based cluster analysis, we investigate the structure-transport properties of typical water-in-salt electrolytes. We demonstrate that ions exhibit distinct dynamics across different ionic clusters-namely, solvent-separated ion pairs (SSIPs), contact ion pairs (CIPs), and aggregates (AGGs). We assess the average proportions of various ionic species and their lifetimes. Our method reveals a dynamic decoupling of ion kinetics, with each species independently contributing to the overall molecular motion. This is evidenced by the fact that the total velocity autocorrelation function (VACF) and power spectrum can be expressed as a weighted sum of independent functions for each species. The experimental data on the ionic conductivity of the studied LiTFSI electrolytes align well with our theoretical predictions at various concentrations, based on the proportions and diffusion coefficients of free ions derived from our analysis. The insights gained into the solvation structures and dynamics of different ionic species enable us to elucidate the physical mechanisms driving ion transport in such superconcentrated electrolytes, providing a comprehensive framework for the future design and optimization of electrolytes.
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Affiliation(s)
- Sheng Bi
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux 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, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux 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
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3
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Goloviznina K, Serva A, Salanne M. Speciation of the proton in water-in-salt electrolytes. Faraday Discuss 2024. [PMID: 39005111 DOI: 10.1039/d4fd00027g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Water-in-salt (WiS) electrolytes are promising systems for a variety of energy storage devices. Indeed, they represent a great alternative to conventional organic electrolytes thanks to their environmental friendliness, non-flammability, and good electrochemical stability. Understanding the behaviour of such systems and their local organisation is a key direction for their rational design and successful implementation at the industrial scale. In the present paper, we focus our investigation on the 21 m bis(trifluoromethanesulfonyl)imide (LiTFSI) WiS electrolyte, recently reported to have acidic pH values. We explore the speciation of an excess proton in this system and its dependence on the initial local environment using ab initio molecular dynamics simulations. In particular, we observe the formation of HTFSI acid in the WiS system, known to act as a superacid in water. This acid is stabilised in the WiS solution for several picoseconds thanks to the formation of a complex with water molecules and a neighboring TFSI- anion. We further investigate how the excess proton affects the microstructure of WiS, in particular, the recently observed oligomerisation of lithium cations, and we report possible notable perturbations of the lithium nanochain organisation. These two phenomena are particularly important when considering WiS as electrolytes in batteries and supercapacitors, and our results contribute to the comprehension of these systems at the molecular level.
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Affiliation(s)
- Kateryna Goloviznina
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France.
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
| | - Alessandra Serva
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, 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, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, 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
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4
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Khammari A, Jeon J, Cho M. Solvation Structures and Transport Mechanisms of Cations in Water-in-Bisalt Electrolytes for High-Concentration Lithium-Ion Batteries Revealed by Molecular Dynamics Simulations. J Phys Chem B 2024; 128:5735-5745. [PMID: 38820050 DOI: 10.1021/acs.jpcb.4c02001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2024]
Abstract
The development of safe and cost-effective electrolytes for rechargeable batteries is currently underway. While water-based electrolytes hold promise, their restricted electrochemical stability window poses a challenge. Combining multiple ionic species emerges as a promising strategy to broaden this stability window and optimize Li-ion battery performance. This study focuses on dual-cation electrolytes, which blend lithium and potassium acetates to enhance the electrochemical characteristics of the solution at high concentrations. We investigated the solvation structure of each ion and its interactions on a molecular level. Our analysis reveals that ion clusters and aggregates are formed through shared acetate and water molecules at high salt concentrations. Furthermore, the residence time analyses of atom pairs indicate that cations diffuse in vehicular mode at low concentrations. In contrast, they switch to a structural mode at high concentrations due to diminishing water content. This study offers a comprehensive model for exploring diverse solvation structures of cations and gaining insights into their diffusion mechanisms within water-in-bisalt electrolytes for aqueous Li-ion batteries.
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Affiliation(s)
- Anahita Khammari
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Republic of Korea
- Korea University, Seoul 02841, Republic of Korea
| | - Jonggu Jeon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Republic of Korea
- Korea University, Seoul 02841, Republic of Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Republic of Korea
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
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5
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Felsted RG, Graham TR, Zhao Y, Bazak JD, Nienhuis ET, Pauzauskie PJ, Joly AG, Pearce CI, Wang Z, Rosso KM. Anionic Effects on Concentrated Aqueous Lithium Ion Dynamics. J Phys Chem Lett 2024:5076-5087. [PMID: 38708887 DOI: 10.1021/acs.jpclett.4c00585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
The dynamics, orientational anisotropy, diffusivity, viscosity, and density were measured for concentrated lithium salt solutions, including lithium chloride (LiCl), lithium bromide (LiBr), lithium nitrite (LiNO2), and lithium nitrate (LiNO3), with methyl thiocyanate as an infrared vibrational probe molecule, using two-dimensional infrared spectroscopy (2D IR), nuclear magnetic resonance (NMR) spectroscopy, and viscometry. The 2D IR, NMR, and viscosity results show that LiNO2 exhibits longer correlation times, lower diffusivity, and nearly 4 times greater viscosity compared to those of the other lithium salt solutions of the same concentration, suggesting that nitrite anions may strongly facilitate structure formation via strengthening water-ion network interactions, directly impacting bulk solution properties at sufficiently high concentrations. Additionally, the LiNO2 and LiNO3 solutions show significantly weakened chemical interactions between the lithium cations and the methyl thiocyanate when compared with those of the lithium halide salts.
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Affiliation(s)
- Robert G Felsted
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Trent R Graham
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Yatong Zhao
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - J David Bazak
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Emily T Nienhuis
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Peter J Pauzauskie
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
- Materials Science and Engineering Department, University of Washington, Seattle, Washington 98195, United States
| | - Alan G Joly
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Carolyn I Pearce
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
- Department of Crop and Soil Sciences, Washington State University, Pullman, Washington 99164, United States
| | - Zheming Wang
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Kevin M Rosso
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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6
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Mukherjee K, Palchowdhury S, Maroncelli M. Do Electrostatics Control the Diffusive Dynamics of Solitary Water? NMR and MD Studies of Water Translation and Rotation in Dipolar and Ionic Solvents. J Phys Chem B 2024; 128:3689-3706. [PMID: 38588535 DOI: 10.1021/acs.jpcb.3c08300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
NMR-based measurements of the diffusion coefficients and rotation times of solitary water and benzene at 300 K are reported in a diverse collection of 13 conventional organic solvents and 10 imidazolium ionic liquids. Proton chemical shifts of water are found to be correlated to water OH-stretching frequencies, confirming the importance of electrostatic interactions in these shifts. However, the influence of magnetic interactions in aromatic solvents renders chemical shifts a less reliable indicator of electrostatics. Diffusion coefficients (DB) and rotational correlation times (τB) of benzene in the solvents examined are accurately described as functions of viscosity (η) by DB ∝ η-0.81 and τB ∝ η0.64. Literature values of DB and τB in alkane and normal alcohols, which were not included among the solvents studied here, are systematically faster than predicted by these correlations, indicating that factors beyond solvent viscosity play a role in determining the friction on benzene. In contrast to benzene, water diffusion and rotation are poorly described in terms of viscosity alone, even in the dipolar and ionic solvents measured here. The present data and the substantial literature data already available on dilute water diffusion show a systematic dependence of DW on solvent polarity among isoviscous solvents. The aspect of solvent polarity most relevant to water dynamics is the ability of a solvent to accept hydrogen bonds from water, as conveniently quantified by the frequency of water's OH stretching band, ΔνOH. The friction on translation, ζtr = kBT/DW, and rotation, ζrot = kBTτW, are both well correlated by functions of the form ζ(η, ΔνOH) = a1ηa2 exp (a3ΔνOH), where the ai are adjustable parameters. Molecular dynamics simulations reveal a strong coupling between electrostatic and nonelectrostatic water-solvent interactions, which makes it impossible to dissect the friction on water into additive dielectric and hydrodynamic components. Simulations also provide a tentative explanation for the unusual form of the correlating function ζ(η, ΔνOH), at least in the case of ζrot.
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Affiliation(s)
- Kallol Mukherjee
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Sourav Palchowdhury
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mark Maroncelli
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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7
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Wu J, Zhang J, Chen M, Yan J, Mao B, Feng G. Regulating the electrical double layer to prevent water electrolysis for wet ionic liquids with cheap salts. NANOSCALE 2023; 15:18603-18612. [PMID: 37927229 DOI: 10.1039/d3nr04700h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Hydrophobic ionic liquids (ILs), broadly utilized as electrolytes, face limitations in practical applications due to their hygroscopicity, which narrows their electrochemical windows via water electrolysis. Herein, we scrutinized the impact of incorporating cheap salts on the electrochemical stability of wet hydrophobic ILs. We observed that alkali ions effectively manipulate the solvation structure of water and regulate the electrical double layer (EDL) structure by subtly adjusting the free energy distribution of water in wet ILs. Specifically, alkali ions significantly disrupted the hydrogen bond network, reducing free water, strengthening the O-H bond, and lowering water activity in bulk electrolytes. This effect was particularly pronounced in EDL regions, where most water molecules were repelled from both the cathode and anode with the disappearance of the H-bond network connectivity along the EDL. The residual interfacial water underwent reorientation, inhibiting water electrolysis and thus enhancing the electrochemical window of wet hydrophobic ILs. This theoretical proposition was confirmed by cyclic voltammetry measurements, demonstrating a 45% enhancement in the electrochemical windows for salt-in-wet ILs, approximating the dry one. This work offers feasible strategies for tuning the EDL and managing interfacial water activity, expanding the comprehension of interface engineering for advanced electrochemical systems.
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Affiliation(s)
- Jiedu Wu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST), 430074 Wuhan, China.
- State Key Laboratory of Physical Chemistry of Solid Surfaces, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
| | - Jinkai Zhang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST), 430074 Wuhan, China.
| | - Ming Chen
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST), 430074 Wuhan, China.
- Institute of Interdisciplinary Research for Mathematics and Applied Science, Huazhong University of Science and Technology (HUST), 430074 Wuhan, China
| | - Jiawei Yan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
| | - Bingwei Mao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
| | - Guang Feng
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST), 430074 Wuhan, China.
- Institute of Interdisciplinary Research for Mathematics and Applied Science, Huazhong University of Science and Technology (HUST), 430074 Wuhan, China
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8
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Si P, Zheng Z, Gu Y, Geng C, Guo Z, Qin J, Wen W. Nanostructured TiO 2 Arrays for Energy Storage. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16103864. [PMID: 37241492 DOI: 10.3390/ma16103864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/14/2023] [Accepted: 05/14/2023] [Indexed: 05/28/2023]
Abstract
Because of their extensive specific surface area, excellent charge transfer rate, superior chemical stability, low cost, and Earth abundance, nanostructured titanium dioxide (TiO2) arrays have been thoroughly explored during the past few decades. The synthesis methods for TiO2 nanoarrays, which mainly include hydrothermal/solvothermal processes, vapor-based approaches, templated growth, and top-down fabrication techniques, are summarized, and the mechanisms are also discussed. In order to improve their electrochemical performance, several attempts have been conducted to produce TiO2 nanoarrays with morphologies and sizes that show tremendous promise for energy storage. This paper provides an overview of current developments in the research of TiO2 nanostructured arrays. Initially, the morphological engineering of TiO2 materials is discussed, with an emphasis on the various synthetic techniques and associated chemical and physical characteristics. We then give a brief overview of the most recent uses of TiO2 nanoarrays in the manufacture of batteries and supercapacitors. This paper also highlights the emerging tendencies and difficulties of TiO2 nanoarrays in different applications.
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Affiliation(s)
- Pingyun Si
- School of Mechanical and Electrical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, Haikou 570228, China
| | - Zhilong Zheng
- Zhanjiang Power Supply Bureau of Guangdong Power Grid Co., Ltd., Zhanjiang 524001, China
| | - Yijie Gu
- College of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Chao Geng
- School of Mechanical and Electrical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, Haikou 570228, China
| | - Zhizhong Guo
- School of Mechanical and Electrical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, Haikou 570228, China
| | - Jiayi Qin
- School of Mechanical and Electrical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, Haikou 570228, China
| | - Wei Wen
- School of Mechanical and Electrical Engineering, Collaborative Innovation Center of Ecological Civilization, Hainan University, Haikou 570228, China
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9
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Goodwin ZAH, McEldrew MP, de Souza JP, Bazant MZ, Kornyshev AA. Gelation, Clustering and Crowding in the Electrical Double Layer of Ionic Liquids. J Chem Phys 2022; 157:094106. [DOI: 10.1063/5.0097055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Understanding the bulk and interfacial properties of super-concentrated electrolytes, such as ionic liquids (ILs), has attracted significant attention lately for their promising applications in supercapacitors and batteries. Recently, McEldrew et al. developed a theory for reversible ion associations in bulk ILs, which accounted for the formation of all possible Cayley tree clusters and a percolating ionic network (gel). Here we adopt and develop this approach to understand the associations of ILs in the electrical double layer at electrified interfaces. With increasing charge of the electrode, the theory predicts a transition from a regime dominated by a gelled or clustered state to a crowding regime dominated by free ions. This transition from gelation to crowding is conceptually similar to the overscreening to crowding transition.
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Affiliation(s)
| | - Michael Patrick McEldrew
- Massachusetts Institute of Technology Department of Chemical Engineering, United States of America
| | - J. Pedro de Souza
- MIT, Massachusetts Institute of Technology Department of Chemical Engineering, United States of America
| | | | - Alexei A. Kornyshev
- Department of Chemistry, Imperial College London Faculty of Natural Sciences, United Kingdom
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10
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Patsahan O, Ciach A. Mesoscopic Inhomogeneities in Concentrated Electrolytes. ACS OMEGA 2022; 7:6655-6664. [PMID: 35252660 PMCID: PMC8892908 DOI: 10.1021/acsomega.1c06013] [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: 10/27/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
A mesoscopic theory for water-in-salt electrolytes combining density functional and field-theoretic methods is developed in order to explain the unexpectedly large period of the oscillatory decay of the disjoining pressure observed in recent experiments for the lithium bis(trifluoromethylsulfonyl)-imide (LiTFSI) salt [T. S. Groves et al., J. Phys. Chem. Lett. 2021, 12, 1702]. We assumed spherical ions with different diameters and implicit solvent, inducing strong, short-range attraction between ions of the same sign. For this highly simplified model, we calculated correlation functions. Our results indicate that mesoscopic inhomogeneities can occur when the sum of the Coulomb and the water-mediated interactions between like ions is attractive at short and repulsive at large distances. We adjusted the attractive part of the potential to the water-in-LiTFSI electrolyte and obtained both the period and the decay rate of the correlations, in semiquantitative agreement with the experiment. In particular, the decay length of the correlations increases nearly linearly with the volume fraction of ions.
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Affiliation(s)
- Oksana Patsahan
- Institute
for Condensed Matter Physics of the National Academy of Sciences of
Ukraine, Lviv 79011, Ukraine
| | - Alina Ciach
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 01-224 Warszawa, Poland
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11
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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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12
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Machhi HK, Ray D, Panjabi SH, Aswal VK, Soni SS. Effect of redox active multivalent metal salts on micellization of amphiphilic block copolymer for energy storage devices via SANS, DLS and NMR. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Amiri M, Bélanger D. Physicochemical and Electrochemical Properties of Water-in-Salt Electrolytes. CHEMSUSCHEM 2021; 14:2487-2500. [PMID: 33973406 DOI: 10.1002/cssc.202100550] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/19/2021] [Indexed: 06/12/2023]
Abstract
Aqueous electrolytes are attractive for applications in electrochemical technologies due to features like being eco-friendly, cost effective, and non-flammable. Very recently, superconcentrated aqueous electrolytes, such as so-called water-in-salt, water-in-bisalt, and hydrate melt, have received a significant attention for electrochemical energy storage due to enhanced stability and much wider electrochemical stability window. This Review focuses on the physicochemical properties of the highly concentrated electrolytes that are derived from several analysis techniques and simulation. A summary of most common features such as ions-water interactions, structure of species present in the electrolyte, conductivity, and viscosity of the electrolytes found in the literature are presented as well. In addition, this Review explains how these characteristics affect the electrochemical behavior of the electrolyte such as double layer structure and electrode/electrolyte interface leading to enhanced electrochemical stability of aqueous electrolytes.
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Affiliation(s)
- Mona Amiri
- Département de Chimie, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Québec, H3C 3P8, Canada
| | - Daniel Bélanger
- Département de Chimie, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Québec, H3C 3P8, Canada
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14
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Kashin AS, Boiko DA, Ananikov VP. Neural Network Analysis of Electron Microscopy Video Data Reveals the Temperature-Driven Microphase Dynamics in the Ions/Water System. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2007726. [PMID: 33938144 DOI: 10.1002/smll.202007726] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Real-time field-emission scanning electron microscopy (FE-SEM) measurements and neural network analysis were successfully merged to observe the temperature-induced behavior of soft liquid microdomains in mixtures of different ionic liquids with water. The combination of liquid FE-SEM and in situ heating techniques revealed temperature-driven solution restructuring for ions/water systems with different water states and their critical point behavior expressed in a rapid switch between thermal expansion and shrinkage of liquid microphases at temperatures of ≈100-130 °C, which was directly recorded on electron microscopy videos. Automation of FE-SEM video analysis by a neural network approach allowed quantification of the morphological changes in ions/water systems during heating on the basis of thousands of images processed with a speed almost equal to the frame rate of original electron microscopy videos. Tracking and evolution of the micro-heterogeneous domains, hypothesized in the Ioliomics concept, was mapped and quantified for the first time. The present study describes the concept for quick acquisition of big data in electron microscopy, develops rapid neural network analysis and shows how to link microscopic data to fundamental molecular properties.
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Affiliation(s)
- Alexey S Kashin
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow, 119991, Russian Federation
| | - Daniil A Boiko
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow, 119991, Russian Federation
| | - Valentine P Ananikov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow, 119991, Russian Federation
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15
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Wei F, Cui X, Wang Z, Dong C, Li J, Han X. Recoverable peroxidase-like Fe 3O 4@MoS 2-Ag nanozyme with enhanced antibacterial ability. CHEMICAL ENGINEERING JOURNAL (LAUSANNE, SWITZERLAND : 1996) 2021; 408:127240. [PMID: 33052192 DOI: 10.1016/j.cej.2020.127241] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 05/24/2023]
Abstract
Antibacterial agents with enzyme-like properties and bacteria-binding ability have provided an alternative method to efficiently disinfect drug-resistance microorganism. Herein, a Fe3O4@MoS2-Ag nanozyme with defect-rich rough surface was constructed by a simple hydrothermal method and in-situ photodeposition of Ag nanoparticles. The nanozyme exhibited good antibacterial performance against E. coli (~69.4%) by the generated ROS and released Ag+, while the nanozyme could further achieve an excellent synergistic disinfection (~100%) by combining with the near-infrared photothermal property of Fe3O4@MoS2-Ag. The antibacterial mechanism study showed that the antibacterial process was determined by the collaborative work of peroxidase-like activity, photothermal effect and leakage of Ag+. The defect-rich rough surface of MoS2 layers facilitated the capture of bacteria, which enhanced the accurate and rapid attack of •OH and Ag+ to the membrane of E. coli with the assistance of local hyperthermia. This method showed broad-spectrum antibacterial performance against Gram-negative bacteria, Gram-positive bacteria, drug-resistant bacteria and fungal bacteria. Meanwhile, the magnetism of Fe3O4 was used to recycle the nanozyme. This work showed great potential of engineered nanozymes for efficient disinfection treatment.
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Affiliation(s)
- Feng Wei
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Xinyu Cui
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Zhao Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Changchang Dong
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Jiadong Li
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Xiaojun Han
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
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16
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Dhattarwal HS, Remsing RC, Kashyap HK. Intercalation-deintercalation of water-in-salt electrolytes in nanoscale hydrophobic confinement. NANOSCALE 2021; 13:4195-4205. [PMID: 33586725 DOI: 10.1039/d0nr08163a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Intercalation-deintercalation of water-in-salt (WIS) electrolytes in nanoscale confinement is an important phenomenon relevant to energy storage and self-assembly applications. In this article, we use molecular simulations to investigate the effects of intersurface separation on the structure and free energy underlying the intercalation-deintercalation of the Li bis(trifluoromethane)sulfonimide ([Li][TFSI]) water-in-salt (WIS) electrolyte confined between nanoscale hydrophobic surfaces. We employ enhanced sampling to estimate the free energy profiles for the intercalation behaviour of WIS in confining sheets at several intersurface separations. We observe that the relative stability of the condensed and vapour phases of WIS in the confinement depends on the separation between the confining surfaces and the WIS concentration. We find that the critical separation at which the condensed and vapour phases are equally stable in confinement depends on the concentration of WIS. The relative height of the free energy barrier also strongly depends on the concentration of [Li][TFSI] inside the confined space, and we find that this concentration dependence can be attributed to changes in line tension. The process of deintercalation passes through vapour tube formation inside the confined space, and this process is initiated by vapour bubble formation. The size of the critical vapour tube required for spontaneous evaporation of WIS from the confinement is also found to depend on the intersurface separation and WIS concentration.
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Affiliation(s)
- Harender S Dhattarwal
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
| | - Richard C Remsing
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Hemant K Kashyap
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
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Groves TS, Perez-Martinez CS, Lhermerout R, Perkin S. Surface Forces and Structure in a Water-in-Salt Electrolyte. J Phys Chem Lett 2021; 12:1702-1707. [PMID: 33560858 DOI: 10.1021/acs.jpclett.0c03718] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Water-in-salt electrolytes are a fascinating new class of highly concentrated aqueous solutions with wide electrochemical stability windows that make them viable as aqueous battery electrolytes. However, the high ion concentration of water-in-salt electrolytes means that these systems are poorly understood when compared to more dilute electrolyte solutions. Here, we present direct surface force measurements across thin films of a water-in-salt electrolyte at several concentrations. We find that the electrolyte adopts a layered structure at charged interfaces composed of a nanostructure of a hydrated cation and nonaqueous anion-rich domains. These observations will aid in the interpretation of capacitance and double-layer behavior of water-in-salt electrolytes with consequences for their use in energy storage devices.
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Affiliation(s)
- Timothy S Groves
- Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 2JD, U.K
| | | | - Romain Lhermerout
- Laboratoire Charles Coulomb, Université de Montpellier, CNRS, 34090 Montpellier, France
| | - Susan Perkin
- Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 2JD, U.K
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Ah-Lung G, Flamme B, Ghamouss F, Maréchal M, Jacquemin J. Guidelines for designing highly concentrated electrolytes for low temperature applications. Chem Commun (Camb) 2020; 56:9830-9833. [PMID: 32716427 DOI: 10.1039/d0cc03963b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The redefinition of the commonly named "water-in-salt" clarifies the operating temperatures of the state-of-the-art LiTFSI-based aqueous solutions. An in-depth study shows its mismatch for low temperature applications. In contrast, the recommended strategy is to design an electrolyte with an invariant composition, as exemplified by the eutectic water/LiNO3 that is able to electrochemically cycle down to -23 °C.
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Affiliation(s)
- Guillaume Ah-Lung
- Laboratoire PCM2E, Université de Tours, Parc de Grandmont, 37200 Tours, France.
| | - Benjamin Flamme
- Laboratoire PCM2E, Université de Tours, Parc de Grandmont, 37200 Tours, France.
| | - Fouad Ghamouss
- Laboratoire PCM2E, Université de Tours, Parc de Grandmont, 37200 Tours, France. and Materials Science and Nano-Engineering (MSN) Department, Mohammed VI Polytechnic University (UM6P), Lot 660 - Hay Moulay Rachid, 43150, Benguerir, Morocco
| | - Manuel Maréchal
- Univ. Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, 38000 Grenoble, France
| | - Johan Jacquemin
- Laboratoire PCM2E, Université de Tours, Parc de Grandmont, 37200 Tours, France. and Materials Science and Nano-Engineering (MSN) Department, Mohammed VI Polytechnic University (UM6P), Lot 660 - Hay Moulay Rachid, 43150, Benguerir, Morocco
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