1
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Fan M, Shen KH, Hall LM. Effect of Tethering Anions in Block Copolymer Electrolytes via Molecular Dynamics Simulations. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mengdi Fan
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Kuan-Hsuan Shen
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Lisa M. Hall
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States
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2
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Karatrantos AV, Khantaveramongkol J, Kröger M. Structure and Diffusion of Ionic PDMS Melts. Polymers (Basel) 2022; 14:3070. [PMID: 35956584 PMCID: PMC9370667 DOI: 10.3390/polym14153070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/17/2022] [Accepted: 07/26/2022] [Indexed: 12/04/2022] Open
Abstract
Ionic polymers exhibit mechanical properties that can be widely tuned upon selectively charging them. However, the correlated structural and dynamical properties underlying the microscopic mechanism remain largely unexplored. Here, we investigate, for the first time, the structure and diffusion of randomly and end-functionalized ionic poly(dimethylsiloxane) (PDMS) melts with negatively charged bromide counterions, by means of atomistic molecular dynamics using a united atom model. In particular, we find that the density of the ionic PDMS melts exceeds the one of their neutral counterpart and increases as the charge density increases. The counterions are condensed to the cationic part of end-functionalized cationic PDMS chains, especially for the higher molecular weights, leading to a slow diffusion inside the melt; the counterions are also correlated more strongly to each other for the end-functionalized PDMS. Temperature has a weak effect on the counterion structure and leads to an Arrhenius type of behavior for the counterion diffusion coefficient. In addition, the charge density of PDMS chains enhances the diffusion of counterions especially at higher temperatures, but hinders PDMS chain dynamics. Neutral PDMS chains are shown to exhibit faster dynamics (diffusion) than ionic PDMS chains. These findings contribute to the theoretical description of the correlations between structure and dynamical properties of ion-containing polymers.
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Affiliation(s)
- Argyrios V. Karatrantos
- Materials Research and Technology, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg;
| | - Jettawat Khantaveramongkol
- Materials Research and Technology, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg;
| | - Martin Kröger
- Polymer Physics, Department of Materials, ETH Zurich, Leopold-Ruzicka-Weg 4, CH-8093 Zurich, Switzerland
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3
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Paren BA, Nguyen N, Ballance V, Hallinan DT, Kennemur JG, Winey KI. Superionic Li-Ion Transport in a Single-Ion Conducting Polymer Blend Electrolyte. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00459] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Benjamin A. Paren
- Department of Materials Science & Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Nam Nguyen
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Valerie Ballance
- Department of Materials Science & Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Daniel T. Hallinan
- Department of Chemical and Biomedical Engineering, Florida A&M University−Florida State University (FAMU-FSU) College of Engineering, 2525 Pottsdamer Street, Tallahassee, Florida 32310, United States
| | - Justin G. Kennemur
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Karen I. Winey
- Department of Materials Science & Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
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4
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Liu H, Luo X, Sokolov AP, Paddison SJ. Quantitative Evidence of Mobile Ion Hopping in Polymerized Ionic Liquids. J Phys Chem B 2021; 125:372-381. [PMID: 33393762 DOI: 10.1021/acs.jpcb.0c06916] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Atomistic molecular dynamics simulations were performed, and an extensive set of analyses were undertaken to understand the ion transport mechanism in the polymerized ionic liquid poly(C2VIm)Tf2N. The ion hopping events were investigated at different time scales. Ion hopping was examined by monitoring the instantaneous cation-anion association and dissociation. Ion diffusion was subsequently evaluated with correlation functions and the calculation of relaxation times at different time scales. Dynamical heterogeneity in the mobility of the ions was observed with only a small portion of the anions classified as fast mobile ions. The mobile ions were characterized as the ones traveling farther than a certain distance during a characteristic period, which was much longer than the time scale of the instant ion pair dissociation. Effective hopping of the mobile ions contributed to the diffusivity which was dominated by interchain hopping and generally facilitated with five associating cations from two different polymer chains. Mobile anions had relatively fewer associating cations from more associating chains than immobile anions. The stringlike cooperative motion was observed in the mobile anions. The string length was determined to decrease with increasing temperature. These findings provided an in-depth understanding of the ion transport in polymerized ionic liquids and important information for the rational design of novel materials.
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Affiliation(s)
- Hongjun Liu
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Xubo Luo
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Alexei P Sokolov
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Stephen J Paddison
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
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5
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Shen Z, Chen QP, Xie S, Lodge TP, Siepmann JI. Effects of Electrolytes on Thermodynamics and Structure of Oligo(ethylene oxide)/Salt Solutions and Liquid–Liquid Equilibria of a Squalane/Tetraethylene Glycol Dimethyl Ether Blend. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c02270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhengyuan Shen
- Department of Chemical Engineering and Material Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
- Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Qile P. Chen
- Department of Chemical Engineering and Material Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
- Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Shuyi Xie
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Timothy P. Lodge
- Department of Chemical Engineering and Material Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - J. Ilja Siepmann
- Department of Chemical Engineering and Material Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
- Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
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6
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Paren BA, Thurston BA, Neary WJ, Kendrick A, Kennemur JG, Stevens MJ, Frischknecht AL, Winey KI. Percolated Ionic Aggregate Morphologies and Decoupled Ion Transport in Precise Sulfonated Polymers Synthesized by Ring-Opening Metathesis Polymerization. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01906] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Benjamin A. Paren
- Dept. Of Materials Science & Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272, United States
| | - Bryce A. Thurston
- Center for Integrated Nanotechnologies, Sandia National Labs, Albuquerque, New Mexico 87185-1411, United States
| | - William J. Neary
- Dept. Of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Aaron Kendrick
- Dept. Of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Justin G. Kennemur
- Dept. Of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Mark J. Stevens
- Center for Integrated Nanotechnologies, Sandia National Labs, Albuquerque, New Mexico 87185-1411, United States
| | - Amalie L. Frischknecht
- Center for Integrated Nanotechnologies, Sandia National Labs, Albuquerque, New Mexico 87185-1411, United States
| | - Karen I. Winey
- Dept. Of Materials Science & Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272, United States
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7
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Bollinger JA, Stevens MJ, Frischknecht AL. Quantifying Single-Ion Transport in Percolated Ionic Aggregates of Polymer Melts. ACS Macro Lett 2020; 9:583-587. [PMID: 35648490 DOI: 10.1021/acsmacrolett.0c00139] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Single-ion conducting polymers such as ionomers are promising battery electrolyte materials, but it is critical to understand how rates and mechanisms of free cation transport depend on the nanoscale aggregation of cations and polymer-bound anions. We perform coarse-grained molecular dynamics simulations of ionomer melts to understand cation mobility as a function of polymer architecture, background relative permittivity, and corresponding ionic aggregate morphology. In systems exhibiting percolated ionic aggregates, cations diffuse via stepping motions along the ionic aggregates. These diffusivities can be quantitatively predicted by calculating the lifetimes of continuous association between oppositely charged ions, which equal the time scales of the stepping (diffusive) motions. In contrast, predicting cation diffusivity for systems with isolated ionic aggregates requires another time scale. Our results suggest that to improve conductivity the Coulombic interaction strength should be strong enough to favor percolated aggregates but weak enough to facilitate ion dissociation.
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Affiliation(s)
- Jonathan A. Bollinger
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Mark J. Stevens
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Amalie L. Frischknecht
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
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8
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Yan L, Hoang L, Winey KI. Ionomers from Step-Growth Polymerization: Highly Ordered Ionic Aggregates and Ion Conduction. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02220] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Lu Yan
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, United States
| | - Lauren Hoang
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, United States
| | - Karen I. Winey
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, United States
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9
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Frischknecht AL, Paren BA, Middleton LR, Koski JP, Tarver JD, Tyagi M, Soles CL, Winey KI. Chain and Ion Dynamics in Precise Polyethylene Ionomers. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01712] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Amalie L. Frischknecht
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Benjamin A. Paren
- Department of Materials Science and Engineering and Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - L. Robert Middleton
- Department of Materials Science and Engineering and Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jason P. Koski
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Jacob D. Tarver
- NIST Center for Neutron Research, Gaithersburg, Maryland 20899-1070, United States
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, Gaithersburg, Maryland 20899-1070, United States
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Christopher L. Soles
- NIST Center for Neutron Research, Gaithersburg, Maryland 20899-1070, United States
| | - Karen I. Winey
- Department of Materials Science and Engineering and Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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10
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Zhang H, Wang X, Chremos A, Douglas JF. Superionic UO2: A model anharmonic crystalline material. J Chem Phys 2019; 150:174506. [DOI: 10.1063/1.5091042] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Xinyi Wang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Alexandros Chremos
- Material Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Jack F. Douglas
- Material Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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11
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Frischknecht AL, Winey KI. The evolution of acidic and ionic aggregates in ionomers during microsecond simulations. J Chem Phys 2019; 150:064901. [PMID: 30769997 DOI: 10.1063/1.5085069] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We performed microsecond-long, atomistic molecular dynamics simulations on a series of precise poly(ethylene-co-acrylic acid) ionomers neutralized with lithium, with three different spacer lengths between acid groups on the ionomers and at two temperatures. Ionic aggregates form in these systems with a variety of shapes ranging from isolated aggregates to percolated aggregates. At the lower temperature of 423 K, the ionic aggregate morphologies do not reach a steady-state distribution over the course of the simulations. At the higher temperature of 600 K, the aggregates are sufficiently mobile that they rearrange and reach steady state after hundreds of nanoseconds. For systems that are 100% neutralized with lithium, the ions form percolated aggregates that span the simulation box in three directions, for all three spacer lengths (9, 15, and 21). In the partially neutralized systems, the morphology includes lithium ion aggregates that may also include some unneutralized acid groups, along with a coexisting population of acid group aggregates that form through hydrogen bonding. In the lithium ion aggregates, unneutralized acid groups tend to be found on the ends or sides of the aggregates.
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Affiliation(s)
- Amalie L Frischknecht
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Karen I Winey
- Department of Materials Science and Engineering and Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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12
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Cheng Y, Yang J, Hung JH, Patra TK, Simmons DS. Design Rules for Highly Conductive Polymeric Ionic Liquids from Molecular Dynamics Simulations. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00572] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yizi Cheng
- Department of Polymer Engineering, University of Akron, 250 South Forge St., Akron, Ohio 44325, United States
| | - Junhong Yang
- Department of Polymer Engineering, University of Akron, 250 South Forge St., Akron, Ohio 44325, United States
| | - Jui-Hsiang Hung
- Department of Polymer Engineering, University of Akron, 250 South Forge St., Akron, Ohio 44325, United States
| | - Tarak K. Patra
- Department of Polymer Engineering, University of Akron, 250 South Forge St., Akron, Ohio 44325, United States
| | - David S. Simmons
- Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, Florida 33612, United States
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13
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Cheerla R, Krishnan M. Molecular mechanism of melting of a helical polymer crystal: Role of conformational order, packing and mobility of polymers. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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14
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Abstract
In this review we summarize recent efforts in understanding nano-aggregation in acid- and ion-containing polymer systems. The acid and ionic groups have specific interactions that drive aggregation and alter polymer behavior at the nano-, micro-, and bulk length scales. Advancements in synthetic methods, characterization techniques, and computer simulations have enabled researchers to better understand the morphologies and dynamics, particularly at the nanoscale. This overview of recent advancements in nano-aggregated polymer systems highlights the current understanding of the field and presents promising directions for future investigations and new applications.
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Affiliation(s)
- L. Robert Middleton
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272
| | - Karen I. Winey
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272
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15
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Rudzinski JF, Lu K, Milner ST, Maranas JK, Noid WG. Extended Ensemble Approach to Transferable Potentials for Low-Resolution Coarse-Grained Models of Ionomers. J Chem Theory Comput 2017; 13:2185-2201. [DOI: 10.1021/acs.jctc.6b01160] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph F. Rudzinski
- Department
of Chemistry and ‡Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Keran Lu
- Department
of Chemistry and ‡Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Scott T. Milner
- Department
of Chemistry and ‡Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Janna K. Maranas
- Department
of Chemistry and ‡Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - William G. Noid
- Department
of Chemistry and ‡Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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16
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Lu K, Maranas JK, Milner ST. Depletion attraction of sheet-like ion aggregates in low-dielectric ionomer melts. J Chem Phys 2017; 146:064901. [PMID: 28201882 DOI: 10.1063/1.4973931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Ionomers are polymers in which an ionic group is covalently bonded to the polymer backbone. Ion aggregates in ionomers have morphologies that allow for the packing of the attached polymer backbone. Using ion-only coarse-grained molecular dynamics, we observe that string-like ion aggregates become flat and sheet-like at lower dielectric constants. A consequence of the changing morphology is that the sheet-like aggregates self-assemble to form ordered, lamellar structures. We use a simple thermodynamic model to demonstrate that depletion attraction mediated by small aggregates can explain the observed order. Our results suggest that depletion attraction can drive ions to form structures that have the size scale suggested by direct visualization, produce the commonly observed experimental correlation peak from X-ray and neutron scattering, and satisfy chain-packing constraints that have been demonstrated to be important in simulations.
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Affiliation(s)
- Keran Lu
- The Pennsylvania State University, 120 Fenske Laboratory, University Park, Pennsylvania 16802, USA
| | - Janna K Maranas
- The Pennsylvania State University, 120 Fenske Laboratory, University Park, Pennsylvania 16802, USA
| | - Scott T Milner
- The Pennsylvania State University, 120 Fenske Laboratory, University Park, Pennsylvania 16802, USA
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17
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Savoie BM, Webb MA, Miller TF. Enhancing Cation Diffusion and Suppressing Anion Diffusion via Lewis-Acidic Polymer Electrolytes. J Phys Chem Lett 2017; 8:641-646. [PMID: 28075599 DOI: 10.1021/acs.jpclett.6b02662] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Solid polymer electrolytes (SPEs) have the potential to increase both the energy density and stability of lithium-based batteries, but low Li+ conductivity remains a barrier to technological viability. SPEs are designed to maximize Li+ diffusivity relative to the anion while maintaining sufficient salt solubility. It is thus remarkable that poly(ethylene oxide) (PEO), the most widely used SPE, exhibits Li+ diffusivity that is an order of magnitude smaller than that of typical counterions at moderate salt concentrations. We show that Lewis-basic polymers like PEO favor slow cation and rapid anion diffusion, while this relationship can be reversed in Lewis-acidic polymers. Using molecular dynamics, polyboranes are identified that achieve up to 10-fold increases in Li+ diffusivities and significant decreases in anion diffusivities, relative to PEO in the dilute-ion regime. These results illustrate a general principle for increasing Li+ diffusivity and transference number with chemistries that exhibit weaker cation and stronger anion coordination.
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Affiliation(s)
- Brett M Savoie
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena , California 91125, United States
| | - Michael A Webb
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena , California 91125, United States
| | - Thomas F Miller
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena , California 91125, United States
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18
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Chen X, Chen F, Forsyth M. Molecular dynamics study of the effect of tetraglyme plasticizer on dual-cation ionomer electrolytes. Phys Chem Chem Phys 2017; 19:16426-16432. [DOI: 10.1039/c7cp02129a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
MD shows that tetraglyme could chelate ions and disconnect them from ion clusters in ionomers, which could compromise tetraglyme's plasticization effect.
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Affiliation(s)
- Xingyu Chen
- Institute for Frontier Materials (IFM)
- Deakin University
- Australia
| | - Fangfang Chen
- Institute for Frontier Materials (IFM)
- Deakin University
- Australia
| | - Maria Forsyth
- Institute for Frontier Materials (IFM)
- Deakin University
- Australia
- ARC Centre of Excellence for Electromaterials Science (ACES) Burwood
- Victoria
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19
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LaFemina NH, Chen Q, Colby RH, Mueller KT. The diffusion and conduction of lithium in poly(ethylene oxide)-based sulfonate ionomers. J Chem Phys 2016. [DOI: 10.1063/1.4962743] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Nikki H. LaFemina
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Quan Chen
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Ralph H. Colby
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Karl T. Mueller
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, USA
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20
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Lu K, Maranas JK, Milner ST. Ion-mediated charge transport in ionomeric electrolytes. SOFT MATTER 2016; 12:3943-3954. [PMID: 27019986 DOI: 10.1039/c6sm00524a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ionomers, or single-ion conductors, serve as a model system to study ion transport in polymeric systems. Conductivity is a system property that depends on the net charge transport in the system. The mechanism through which ions are transported can dramatically change the contribution of an ion's self-motion (i.e. diffusion coefficient) to the conductivity of the system. For example, positive and negative ions diffusing as a pair have no net contribution to conductivity. In a coarse-grained molecular dynamics simulation of sodium-neutralized poly(PEO-co-sulfoisophthalate), we show that ion transport is mediated through consecutive coordination with ion pairs and higher order clusters due to the high density of ions. This transport mechanism is highly efficient and shows evidence of cation relaying. We show that larger ion aggregates can serve as ion-conducting paths for positive charges, and demonstrate how a highly ordered ion aggregate network can improve conductivity by enhancing correlated ion transport.
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Affiliation(s)
- Keran Lu
- Pennsylvania State University, Department of Chemical Engineering, 120 Fenske Laboratory, University Park, PA 16802, USA.
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21
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Webb MA, Savoie BM, Wang ZG, Miller III TF. Chemically Specific Dynamic Bond Percolation Model for Ion Transport in Polymer Electrolytes. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01437] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Michael A. Webb
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Brett M. Savoie
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Zhen-Gang Wang
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Thomas F. Miller III
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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22
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Sinha K, Maranas J. Does Ion Aggregation Impact Polymer Dynamics and Conductivity in PEO-Based Single Ion Conductors? Macromolecules 2014. [DOI: 10.1021/ma401856z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kokonad Sinha
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Janna Maranas
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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Lu K, Rudzinski JF, Noid WG, Milner ST, Maranas JK. Scaling behavior and local structure of ion aggregates in single-ion conductors. SOFT MATTER 2014; 10:978-989. [PMID: 24983107 DOI: 10.1039/c3sm52671b] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Single-ion conductors are attractive electrolyte materials because of their inherent safety and ease of processing. Most ions in a sodium-neutralized PEO sulfonated-isophthalate ionomer electrolyte exist as one dimensional chains, restricted in dimensionality by the steric hindrance of the attached polymer. Because the ions are slow to reconfigure, atomistic MD simulations of this material are unable to adequately sample equilibrium ion structures. We apply a novel coarse-graining scheme using a generalized-YBG procedure in which the polymer backbone is completely removed and implicitly represented by the effective potentials of the remaining ions. The ion-only coarse-grained simulation allows for substantial sampling of equilibrium aggregate configurations. We extend the wormlike micelle theory to model ion chain equilibrium. Our aggregates are random walks which become more positively charged with increasing size. Defects occur on the string-like structure in the form of “dust” and “knots,” which form due to cation coordination with open sites along the string. The presence of these defects suggest that cation hopping along open third-coordination sites could be an important mechanism of charge transport using ion aggregates.
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