Decoupling of ionic conductivity from segmental dynamics

Alexei P. Sokolov, University of Tennessee Knoxville, DMR 1059562

In contrast to textbook knowledge, our studies reveal strong decoupling between ionic conductivity and segmental relaxation in polymers. This decoupling drastically increases with increase in the steepness of the temperature variation of segmental relaxation m (fragility).

This finding suggests a new way to design of polymer electrolytes for energy storage applications and might lead to discovery of ‘superionic polymers’.

In fragile polymers ionic conductivity () exhibits much weaker

temperature variations than segmental dynamics (solid line).

A.L. Agapov, A.P. Sokolov., Macromolecules 44, 4410 (2011)

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duct

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s-1]

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Broader Impact: The presented finding have significant implications on our understanding of the ionic transport in polymers. It might affect significantly the development of new technologies for batteries and fuel cells.

Education: Under this grant, 3 students, K. Kumar, S. Khodadadi and L. Hong have completed their PhD and 2 more, Phil Griffin and Alexander Agapov, still continue their PhD studies. Two undergraduate students, K. Freeman and E. Scott have been actively involved in the research. Dr. Sokolov has been also actively involved in organizing Summer School in Biophysics at UT/ORNL.

Students meet and discuss with leading researchers during the Summer School in Biophysics at UT/ORNL (Knoxville, 2010).

Decoupling of ionic conductivity from segmental dynamics

Alexei P. Sokolov, University of Tennessee Knoxville, DMR 1059562