Ionic transport numbers in polyether networks containing different metal salts

Leveque, M.; Nest, J.F. Le; Gandini, Alessandro; Cheradame, Hervé

doi:10.1002/marc.1983.030040711

Cited by 36 publications

(7 citation statements)

References 22 publications

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“…The equation is where η is the viscosity, r i is the radius of species i, and the factor 6 is appropriate for pure stick conditions. The breakdown is consistent with that implied by earlier self-diffusion measurements in PEO solutions made by radiotracer 16 and pulsed field gradient NMR spin echo 18,19,21 techniques and with previous transport number measurements, [6][7][8]30,31 all of which imply that the cation is the less mobile ionic species. The anomalously small cation mobility and the extent of ion pairing, both of which are deleterious to performance in device applications, are the two key features of the salt-in-polymer solvent electrolytes.…”

Section: Discussionsupporting

confidence: 91%

“…In the latter case the temperature dependence either disappeared (when t + ∼ 0.2) or reversed. In the only case in which the transference numbers of similar solutions (LiClO 4 and LiCF 3 SO 3 at 1:24 in a PEObased network) have been directly measured, Cheradame and co-workers 30,31 reported that t + was 0.2 within experimental error for each solution.…”

Section: Discussionmentioning

confidence: 99%

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Probe Ion Diffusivity Measurements in Salt-in-Polymer Electrolytes: Stokes Radii and the Transport Number Problem

McLin

Angell

1996

J. Phys. Chem.

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In order to explore the factors which distinguish ionic motions in salt-in-polymer electrolytes from those in molecular and aqueous solvents, self-diffusivity measurements of cations and anions have been made utilizing the electrochemical technique of chronoamperometry. Stokes' law radii have been calculated using both the macroscopic and microscopic solvent viscosities and found to differ greatly from the crystal radii. The friction acting on the small cation Ag + is found to be more than a factor of 20 greater than calculated from the microscopic viscosity. Nernst-Einstein conductivities have been calculated for the probe ion species and are found to be much greater than the measured host conductivity on the supposition of comparable host ion diffusivities. The excess conductivity correlates with the ion pairing propensity of the host anions, triflate and perchlorate. Correcting the measured probe diffusivities for ion pair contributions, our data imply host cation transport numbers as low as 0.1.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Probe Ion Diffusivity Measurements in Salt-in-Polymer Electrolytes: Stokes Radii and the Transport Number Problem

McLin

Angell

1996

J. Phys. Chem.

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“…Nevertheless, structural modifications of the existing systems remain the most viable alternative to enhance the electrolyte properties. Among the structural modifications like blending, , copolymerization, − grafting, , and cross-linking, − the formation of polymer networks is suggested to be the most effective strategy to achieve low degree of crystallinity as well as good dimensional stability. In this perspective, interpenetrating polymer networks (IPNs) are a special class of polymer networks that can be custom designed to suit specific end uses .…”

Section: Introductionmentioning

confidence: 99%

Polymer Nanocomposites as Solid Electrolytes: Evaluating Ion−Polymer and Polymer−Nanoparticle Interactions in PEG-PU/PAN Semi-IPNs and Titania Systems

2010

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This paper is an investigation on the physicochemical properties and Li ion conductivity behavior of a new class of polymer nanocomposites, which holds promise for its potential use as solid polymer electrolytes (SPE). A family of nanocomposite semi-interpenetrating polymer networks of titania (TiO2)/poly(ethylene glycol)−polyurethane (PEG-PU)/poly(acrylonitrile) (PAN) incorporated with LiClO4 was synthesized. The effects of titania loading, nanoparticle surface functionalization, and ion−polymer and polymer−nanoparticle interactions were evaluated in detail using XRD, FT-IR, TEM, DSC, TG-DTA, and dc conductivity studies. At low degree of TiO2 loading, reasonably good dispersion and encapsulation within the semi-IPN matrix was achieved. FT-IR studies strongly indicate that analogous to the ion−polymer interaction, a strong interaction coexists between the polymer matrix (C−O−C) and the surface of TiO2 nanoparticles. Electron micrographs of the semi-IPN nanocomposite films reveal nanophase separation within the polymer matrix. The larger poly(acrylonitrile) domains (∼50−400 nm) along with interspersed titania nanoparticles (∼5−20 nm) are well distributed throughout the PEG-PU parent networks. The even dispersion and low nanoparticle agglomeration apparent from the micrographs also indicate a reasonable degree of polymer−nanoparticle interaction. Interestingly, no substantial change in the thermal properties of the polymer−nanocomposite matrices is observed even with increased amounts of TiO2 loading (up to 5%) and the glass-transition temperature remained well below the ambient (∼−38 °C). The degradation onset temperature for the semi-IPNs and TiO2 nanocomposites (T 0 ∼ 250 °C) suggests good thermal stability of the matrix. An enhancement in ionic conductivity for all the semi-IPN/nanocomposite was observed. The presence of a very disordered polymer phase in the near vicinity of the nanoparticle surface, interfacial dynamics possibly creating smaller domains of PEG segments wherein the cations (Li+) are more loosely cross-linked under the circumstances of competitive interactions, may help faster ionic transport contributing to the overall increase in the bulk conductivity. Overall, tailoring the polymer−nanocomposite matrices further holds promise toward addressing the practical challenges in the success of solid polymer electrolytes in Li+ ion batteries/dye-sensitized solar cells.

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“…It is difficult to apply this method to polymer systems because of the requirement to maintain the electrolyte as a series of nonadherent sections. Leveque et al 136 were able to carry out such an experiment for highly cross-linked networks where the electrolyte could readily be separated into its component sections after the passage of the current. Bouridah et al 140 developed a technique based on the measurement of emf 26 of a concentration cell formed by contacting two previously thermally activated half cells.…”

Section: Methods Of Determining the Transference Numbermentioning

confidence: 99%

“…For polymer electrolytes, however, these methods are inapplicable and a number of alternate methods have been developed. [136][137][138][139][140][141][142] The Tubandt method 139 is the technique most commonly applied to conventional solid electrolytes. It is directly based on Faraday's laws and requires weight variations in the electrolyte regions near the two cell electrodes caused by the passage of a known amount of charge, to be measured.…”

Section: Methods Of Determining the Transference Numbermentioning

confidence: 99%