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Affiliation(s)
- T. C. Mike Chung
- Department
of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802,
United States
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Kunze M, Karatas Y, Wiemhöfer HD, Schönhoff M. Correlations of Ion Motion and Chain Motion in Salt-in-Polysiloxane-g-oligoether Electrolytes. Macromolecules 2012. [DOI: 10.1021/ma3014405] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Miriam Kunze
- Institute of Physical Chemistry
and SFB 458, University of Münster, Corrensstrasse 28/30, 48149 Münster, Germany
| | - Yunus Karatas
- Institute of Inorganic and Analytical
Chemistry and SFB 458, University of Münster, Corrensstrasse 28/30, 48149 Münster, Germany
| | - Hans-Dieter Wiemhöfer
- Institute of Inorganic and Analytical
Chemistry and SFB 458, University of Münster, Corrensstrasse 28/30, 48149 Münster, Germany
| | - Monika Schönhoff
- Institute of Physical Chemistry
and SFB 458, University of Münster, Corrensstrasse 28/30, 48149 Münster, Germany
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Wang Y, Agapov AL, Fan F, Hong K, Yu X, Mays J, Sokolov AP. Decoupling of ionic transport from segmental relaxation in polymer electrolytes. PHYSICAL REVIEW LETTERS 2012; 108:088303. [PMID: 22463582 DOI: 10.1103/physrevlett.108.088303] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Indexed: 05/21/2023]
Abstract
We present detailed studies of the relationship between ionic conductivity and segmental relaxation in polymer electrolytes. The analysis shows that the ionic conductivity can be decoupled from segmental dynamics and the strength of the decoupling correlates with the fragility but not with the glass transition temperature. These results call for a revision of the current picture of ionic transport in polymer electrolytes. We relate the observed decoupling phenomenon to frustration in packing of rigid polymers, where the loose local structure is also responsible for the increase in their fragility.
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Affiliation(s)
- Yangyang Wang
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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Kunze M, Schulz A, Wiemhöfer HD, Eckert H, Schönhoff M. Transport Mechanisms of Ions in Graft-Copolymer Based Salt-in-Polymer Electrolytes. ACTA ACUST UNITED AC 2010. [DOI: 10.1524/zpch.2010.0036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Salt-in-polymer electrolytes based on graft copolymers with oligoether side chains and added LiCF3SO3 (LiTf) are investigated concerning the transport and dynamics of the ionic species with respect to applications as Li ion conductors. Polymer architectures are based on polysiloxane or polyphosphazene backbones with one or two side chains per monomer, respectively. NMR methods provide information about molecular dynamics on different length scales: The mechanisms governing local dynamics and long range mass transport are studied on the basis of temperature dependent spin-lattice relaxation rates and pulsed field gradient diffusion measurements for 7Li, 19F and 1H, respectively. The correlation times characterizing local ion dynamics reflect the complexation of the cations by the oligoether side chains of the polymer. 7Li and 19F diffusion coefficients and their activation energies are rather similar, suggesting the formation of ion pairs and clusters with similar activation barriers for cation and/or anion long-range transport. Activation energies of local reorientations are generally significantly smaller than activation energies of long range diffusion. Long range transport is affected by (1) the coupling of conformational side chain reorientations to the cation movement, and (2) the correlated diffusion of cations and anions within ion pairs. Ion pairs and their dissociation play a major role in controlling the resulting conductivity of the material. Guidelines for material optimization in terms of a maximized conductivity can thus be derived by identifying a compromise between high ionic mobility and good Li complexation by the coordinating side chains.
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Affiliation(s)
- Miriam Kunze
- Westfälische Wilhelms-Universität, Institut f. Physikalische Chemie, Münster
| | - Alexander Schulz
- Westfälische Wilhelms-Universität, Institut f. Physikalische Chemie, Münster
| | - Hans-Dieter Wiemhöfer
- Westfälische Wilhelms-Universität, Institut für Anorganische und Analytische Chemie, Münster, Deutschland
| | - Hellmut Eckert
- Universität Münster, Institut für Physikalische Chemie, Münster, Deutschland
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Stolwijk N, Wiencierz M, Fögeling J, Bastek J, Obeidi S. The Use of Radiotracer Diffusion to Investigate Ionic Transport in Polymer Electrolytes: Examples, Effects, and Their Evaluation. Z PHYS CHEM 2010. [DOI: 10.1524/zpch.2010.0017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The paper highlights some remarkable results obtained by applying the radiotracer diffusion (RTD) technique to the study of ionic transport in salt-in-polymer electrolytes. The technique is based on the determination of a radiotracer depth profile by serial sectioning following isothermal diffusion annealing. Unlike alternative methods, RTD is able to measure the self-cation and self-anion diffusivity even for systems dilute in salt. Another unique feature is the capability to investigate foreign-ion diffusion at extremely low concentration levels. Combined with DC conductivity data, RTD may provide a virtually complete picture of mass and charge transport in solid-like polymer electrolytes (SPEs). The paper describes the special SPE-related procedures used in the RTD experiments and their analysis. The advantages of the method will be demonstrated with selected examples of self- and foreign-ion diffusion in prototype SPE systems. We also present prominent examples of RTD dealing with the effects of salt precipitation and oxide nano-particles used as dispersed filler material.
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Affiliation(s)
| | - M. Wiencierz
- Universität Münster, Institut für Materialphysik, Münster
| | - J. Fögeling
- Universität Münster, Institut für Materialphysik, Münster
| | - J. Bastek
- Universität Münster, Institut für Materialphysik, Münster
| | - Sh. Obeidi
- Universität Münster, Institut für Materialphysik, Münster
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Zhao J, Zhang G, Pispas S. Thermoresponsive brush copolymers with poly(propylene oxide-ran-ethylene oxide) side chains via metal-free anionic polymerization “grafting from” technique. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pola.23997] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Fögeling J, Kunze M, Schönhoff M, Stolwijk NA. Foreign-ion and self-ion diffusion in a crosslinked salt-in-polyether electrolyte. Phys Chem Chem Phys 2010; 12:7148-61. [DOI: 10.1039/b923894h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sato K, Murakami H, Ito K, Hirata K, Kobayashi Y. Probing the Elemental Environment around the Free Volume in Polymers with Positron Annihilation Age−Momentum Correlation Spectroscopy. Macromolecules 2009. [DOI: 10.1021/ma900462a] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. Sato
- Department of Environmental Sciences, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-8501, Japan
| | - H. Murakami
- Department of Environmental Sciences, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-8501, Japan
| | - K. Ito
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
| | - K. Hirata
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
| | - Y. Kobayashi
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
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Combined analysis of self-diffusion, conductivity, and viscosity data on room temperature ionic liquids. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2008.09.051] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Maitra A, Heuer A. Understanding Correlation Effects for Ion Conduction in Polymer Electrolytes. J Phys Chem B 2008; 112:9641-51. [DOI: 10.1021/jp711563a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Arijit Maitra
- Westfälische Wilhelms-Universität Münster, Institut für Physikalische Chemie, Corrensstrasse 30, 48149 Münster, Germany, and NRW Graduate School of Chemistry, Corrensstrasse 36, 48149 Münster, Germany
| | - Andreas Heuer
- Westfälische Wilhelms-Universität Münster, Institut für Physikalische Chemie, Corrensstrasse 30, 48149 Münster, Germany, and NRW Graduate School of Chemistry, Corrensstrasse 36, 48149 Münster, Germany
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Stolwijk N, Wiencierz M, Obeidi S. Self-diffusion versus ion conduction in polymer electrolytes: On the occurrence of pairs, triplets, and higher-order clusters. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2007.03.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Stolwijk NA, Wiencierz M, Obeidi SH. Mass and charge transport in the PEO–NaI polymer electrolyte system: effects of temperature and salt concentration. Faraday Discuss 2007; 134:157-69; discussion 215-33, 415-9. [PMID: 17326567 DOI: 10.1039/b602143n] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic transport in amorphous complexes of poly(ethylene oxide) (PEO) and sodium iodide (NaI) was investigated by means of radiotracer diffusion and electrical conductivity measurements for three different compositions characterised by O-to-Na ratios of 20, 30, and 60. The diffusivity of 22Na and 125I as well as the charge diffusivity each show a systematic dependence on both temperature and salt concentration. The experimental data can be described within a transport model based on the occurrence of neutral ion pairs in addition to charged single cations and anions. It is found that both the enthalpy and entropy of ion pair formation decrease with increasing salt concentration. This indicates that the state of coordination between cations and polymer chain segments correlates with the number of available oxygen atoms per cation.
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Affiliation(s)
- N A Stolwijk
- Universität Münster, Institut für Materialphysik and Sonderforschungs-bereich 458, WilhelmKlemm-Str. 10, 48149, Münster, Germany.
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Obeidi S, Stolwijk NA. Rubidium Impurity Diffusion in a Poly(ethylene oxide)−Sodium Iodide Polymer Electrolyte. J Phys Chem B 2006; 110:22496-502. [PMID: 17091992 DOI: 10.1021/jp064105l] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diffusion of the radioisotope (86)Rb in an amorphous polymer-salt complex consisting of poly(ethylene oxide) and sodium iodide was found to be faster at all temperatures investigated than tracer self-diffusion of the smaller alkali metal cation (22)Na. This is the striking result of the first study on impurity diffusion in a polymer electrolyte system and a comparison with ionic self-diffusion and conductivity data previously obtained from the same system. The experimental findings can be rationalized within an ion transport model based on the occurrence of charged single ions and neutral ion pairs. Simultaneous analysis of all data revealed that the diffusivity of Rb(+) is likely to be lower than that of Na(+). Similarly, the diffusivity of RbI(0) pairs was found to be smaller than that of NaI(0) pairs. Surprisingly, the faster overall transport of Rb as measured by radiotracer diffusion appears to be due to a relatively large fraction of RbI pairs, in conjunction with the finding that the ion pair diffusivities exceed the single cation diffusivities by 2 orders of magnitude.
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Affiliation(s)
- Shahmahmood Obeidi
- Institut für Materialphysik and Sonderforschungsbereich 458, University of Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster, Germany
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