Concentration dependence of ionic relaxation in lithium doped polymer electrolytes
Artikel i vetenskaplig tidskrift, 2010

A detailed impedance spectroscopy study at ambient temperature was carried out on polymer electrolytes based on low molecular weight poly(ethylene oxide) 400, poly(propylene oxide) 400 and a random copolymer of molecular weight 600, to which were added LiN(CF3SO2)(2) (LiTFSI) salt. The ionic conductivity exhibits a maximum at intermediate salt concentrations and is significantly higher for poly(ethylene oxide) and the copolymer. A dielectric relaxation was found in a frequency region above the one, where the ion conductivity dominates the dielectric response, and below the region of the relaxations of the polymer host. The relaxation strength scales with ion concentration, as appropriate for an ion pair relaxation in systems above the glass transition. The frequency of this relaxation, multiplied by the relaxation strength, has been found to be proportional to the ion conductivity, and the relaxation has therefore been assigned to short-range ionic motion in the polymer. It exhibits characteristics similar to conductivity relaxations in inorganic solid ion conductors, and is considered to be due to the same species that give rise to the ion conductivity. (C) 2010 Elsevier B.V. All rights reserved.

GLASSES

DEVICES

ELECTRICAL-RELAXATION

DIELECTRIC-RELAXATION

POLY(PROPYLENE GLYCOL)

Polymers and organics

Conductivity

CONDUCTIVITY

Relaxation

LICLO4

Electric modulus

Dielectric properties

Författare

Maurizio Furlani

Chalmers, Teknisk fysik, Fasta tillståndets fysik

C. Stappen

Uppsala universitet

Bengt-Erik Mellander

Chalmers, Teknisk fysik, Fasta tillståndets fysik

G. A. Niklasson

Uppsala universitet

Journal of Non-Crystalline Solids

0022-3093 (ISSN)

Vol. 356 11-17 710-714

Fundament

Grundläggande vetenskaper

Styrkeområden

Materialvetenskap

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1016/j.jnoncrysol.2009.07.039