**6. Conclusions**

Nuclear magnetic resonance has proven to be an invaluable tool in the characterization of both structure and dynamics of a wide variety of materials. Its suitability for examining those properties associated with battery performance justifies its continued use in optimizing the electrolytes of the future; advances in both its technology and methodology allow it to remain relevant in the study of the ever-more complex electrolyte systems being developed. The quest for a practical room-temperature solid electrolyte continues, and the polymer electrolyte families described herein are but a small sample of the research towards viability.

**Author Contributions:** As this is a review article, the primary literature search was conducted by S.M. who also wrote most of the manuscript. S.G. defined the scope of the literature to be reviewed and provided some of the technical content, guidance, and editing.

**Funding:** The program on Li batteries at Hunter College is supported by the U.S. Office of Naval Research. S.M. acknowledges financial support by the National Institutes of Health RISE program at Hunter College (grant GM060665).

**Conflicts of Interest:** The authors declare no conflicts of interest.
