Abstract 9424446 Zak The objective of this collaborative project is to synthesize a number of new polymer electrolyte nanocomposites, and to apply a variety of analytical techniques so as to probe structure and dy- namics in the nanocomposite phases for eventual applications in the development of new batteries. Polymer systems are particularly affected when confined, as the local dynamic modes which contribute strongly to bulk mechanical properties are largely determined by interactions between neighboring polymer chains. It should be possible to engineer these systems so as to preferentially retain the beneficial properties while eliminating the undesirable properties, as polymer monolayers are expected to have substantially different properties than the same polymer in bulk. Thus, polymer nanocomposites provide a unique opportunity to study both theoretically challenging and technologically important problems. The major goals of this project are: (1) to characterize fully the microscopic of cation complexation in intercalated polymers, and to explore the extent to which the polymer and cation dynamics are correlated; (2) to explore the specific parameters of the polymer which appear to most influence cation dynamics; (3) to understand which parameters of the cation/polymer/silicate interaction are responsible for the improved conductivity observed for polymer nanocomposites; (4) to provide a sensitive experimental test of available theories of ionic conductance in similar systems; and (5) to explore chemical modifications of nanocomposite materials, based on a systematic understanding of microscopic energetics, which optimize for high ionic conductance. %%% Batteries based on polymer electrolytes are the subject of active R&D competition worldwide. A key unsolved problem is the design and implementation of lightweight, chemically stable and environmentally benign electrolyte/electrode combinations. Particular interest has focused on lithium salts dissolve d in flexible polymers like poly(ethylene oxide), as these polymer electrolytes combine promisingly high ionic conductances with good chemical stability, easy disposability, and are conveniently interfaced to high energy density Li electrodes. One drawback to available polymer electrolytes is the precipitous drop in conductance (from 10-4 to 10-8 S/cm) observed as the polymer is cooled below the melt phase-generally, somewhat above room temperature. The objective of this collaborative project is to synthesize a number of new polymer electrolyte nanocomposites, and to apply a variety of analytical techniques so as to probe structure and dynamics in these nanocomposite phases for eventual applications in the development of new batteries.
