Journal of Power Sources 
August 2000
Volume 89, Issue 2, Pages 168-175

PII: S0378-7753(00)00426-2 
© 2000 Elsevier Science S.A.

The role of polymer melt viscoelastic network behavior in lithium ion
transport for PEO melt/LiClO₄ SPEs: the "wet gel" model 

R. Walter, R. Walkenhorst, M. Smith, J. C. Selser, G. Piet and R. Bogoslovov 
Department of Physics, University of Nevada-Las Vegas, Las Vegas, NV 89154-4002, USA 

(Received 2 September 1999; accepted 6 January 2000. Available online 19 June 2000.)

Abstract:
Earlier light scattering studies revealed that melts of the electrolyte polymer poly(ethylene oxide) (PEO) were not homogeneous but were instead structured and behaved as elastic PEO networks. We report the results of subsequent viscometry measurements that provide a more complete picture of PEO melt structure and dynamic behavior. We find that PEO melts behave as "wet gels," i.e., they behave as elastic PEO networks immersed in a PEO fluid that retards network motions. In addition, a preliminary light scattering examination of the role that PEO melt network dynamic behavior might play in lithium ion transport found that although the light scattering relaxation function mode structure of PEO melt/LiClO₄ solutions changed significantly when the salt concentration was increased from 0 to 20 wt.% -- the latter concentration being that for which maximum conductivity in the PEO/LiClO₄ system has been reported -- the network structure and behavior of the melt was retained. Finally, we report the results of exploratory investigations of several aspects of PEO melt behavior that provide promising directions for future studies of this interesting and important system. 

Article Outline:
1. Introduction
2. Background and rationale
3. Experimental
4. Results and discussion
5. Future directions
6. Conclusions
Acknowledgements
References

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