One of the foremost technological challenges of the coming decades is energy storage for electric vehicles, military, aerospace, and other applications. Our research concerns the evaluation of materials being developed for fuel cells and lithium batteries, which are two technologies undergoing rapid growth. In polymer electrolytes for both fuel cell and lithium battery applications, we investigate the dynamics of ion transport in these disordered media by solid state NMR methods. NMR is also utilized, along with EPR and synchrotron x-ray absorption techniques (EXAFS, XANES), to study local atomic arrangements and electronic band structure of lithium - transition metal oxide insertion compounds being developed for battery electrodes, and noble metal alloys for fuel cell catalysts. The x-ray absorption spectroscopy is conducted at the National Synchrotron Light Source located at nearby (~90 minutes by car) Brookhaven National Lab. In addition to Brookhaven, our group collaborates with several other national labs (Argonne National Lab, NASA Jet Propulsion Lab, Air Force Research Lab and numerous universities, worldwide, on the development and characterization of new power sources.