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Ftir study of ion-pairing effects in plasticized polymer electrolytes

journal contribution
posted on 01.10.1995, 00:00 authored by D MacFarlane, P Meakin, A Bishop, D McNaughton, J Rosalie, Maria ForsythMaria Forsyth
The effect of plasticizer on the ubiquitous ion-pairing observed in polymer electrolytes has been investigated using FTIR as a probe of the local environment of the triflate ion in sodium and lithium triflate based electrolytes. Plasticizers having a range of properties, such as, propylene carbonate, and dimethyl formamide (DMF), have been investigated in the pure state for comparison with the polymer (a random copolymer of ethylene oxide at propylene oxide (mol ratio 3: 1)). The different plasticizers exhibited strikingly different effects on the triflate ion bands normally observed in polyether salt systems. In particular, the cation associated triflate ion bands at 1288 and 1248 cm−1 and the band at 1272 cm−1 which has variously been assigned to the free ion and also to the strongly aggregated anion, are different. PC produces a rapid disappearance of the “free” ion band in favour of the monodentate ion pair. On the other hand, DMF strongly enhances the band near 1270 cm−1 at salt concentrations higher than 0.7 mol kg−1. These observations are discussed in terms of recent ab initio calculations of the triflate vibrational bands.

History

Journal

Electrochimica acta

Volume

40

Issue

13-14

Pagination

2333 - 2337

Publisher

Elsevier Science Pub. Co.

Location

New York, N.Y.

ISSN

0013-4686

eISSN

1873-3859

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1995, Elsevier Science Ltd.