Cover Picture: ChemPhysChem 7/2002

Gorecki, W.; Roux, Christel; Clémancey, Martin; Armand, Michel; Bélorizky, E.

doi:10.1002/1439-7641(20020715)3:7<553::aid-cphc553>3.0.co;2-a

Cited by 14 publications

(27 citation statements)

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“…Detailed characterizations were carried out by methods like infrared spectroscopy [29][30][31], nuclear magnetic resonance (NMR) [32][33][34][35][36][37][38][39][40] and viscosimetry [41][42][43][44] in order to clarify the interaction of the cations with a polymer network and their associated transport dynamics.…”

Section: Introductionmentioning

confidence: 55%

Transport Mechanisms of Ions in Graft-Copolymer Based Salt-in-Polymer Electrolytes

Kunze

Schulz

Wiemhöfer

et al. 2010

Zeitschrift Für Physikalische Chemie

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Polymer Electrolyte / Nuclear Magnetic Resonance / Spin Relaxation / Pulsed Field Gradient NMR / ConductivitySalt-in-polymer electrolytes based on graft copolymers with oligoether side chains and added LiCF 3 SO 3 (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 7 Li, 19 F and 1 H, respectively. The correlation times characterizing local ion dynamics reflect the complexation of the cations by the oligoether side chains of the polymer.7 Li and 19 F 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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Section: Introductionmentioning

confidence: 55%

Transport Mechanisms of Ions in Graft-Copolymer Based Salt-in-Polymer Electrolytes

Kunze

Schulz

Wiemhöfer

et al. 2010

Zeitschrift Für Physikalische Chemie

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show abstract

“…Commonly, the calculated conductivity with the measured self-diffusion coefficients of the fluorine-containing anions D F and the cations D Li (determined by pulsed field gradient NMR) is larger than experimentally observed conductivity [24,[41][42][43][44][45]. Since the diffusion constant of the anion (ClO 4 − ) is unknown in the present study, we cannot accurately calculate the percentage of the conductance that is associated with the cations and with the anions, respectively.…”

Section: LI Diffusion Coefficientsmentioning

confidence: 63%

7Li NMR, ionic conductivity and self-diffusion coefficients of lithium ion and solvent of plasticized organic–inorganic hybrid electrolyte based on PPG-PEG-PPG diamine and alkoxysilanes

Kao

Chang

Chao

et al. 2006

Electrochimica Acta

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“…The inverse trend was observed in our experiment. Gorecki et al [21] have reported similar results for PEOLi[N(SO 2 C n F 2n + 1 )(SO 2 C m F 2m + 1 )] electrolytes (only for symmetrical anions). They consider that the nonpolar character of the perfluoroalkyl chains result in less available space for conduction while their rigidity slows the segmental motion.…”

Section: Ionic Conductivity and Thermal Analysismentioning

confidence: 86%

“…In terms of the size of anions, it was unreasonable. According to NMR results reported by Gorecki et al [21], the size of anion has almost no influence on the transport numbers. Thus, it should be associated with the particular structure of HFPSI anion.…”

Section: Cationic Transference Numbermentioning

confidence: 99%

Characterizations of a branched ester-type lithium imide in poly(ethylene oxide)-based polymer electrolytes

et al. 2004

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Cover Picture: ChemPhysChem 7/2002

Cited by 14 publications

References 0 publications

Transport Mechanisms of Ions in Graft-Copolymer Based Salt-in-Polymer Electrolytes

Transport Mechanisms of Ions in Graft-Copolymer Based Salt-in-Polymer Electrolytes

7Li NMR, ionic conductivity and self-diffusion coefficients of lithium ion and solvent of plasticized organic–inorganic hybrid electrolyte based on PPG-PEG-PPG diamine and alkoxysilanes

Characterizations of a branched ester-type lithium imide in poly(ethylene oxide)-based polymer electrolytes

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