Abstract

Cheaper and more efficient/effective ways to convert and store energy are required to reduce CO2 emissions. Batteries and supercapacitors will play an important role, but significant advances require that we (i) identify new materials for these applications, and (ii) determine how these devices operate over a wide range of time and length scales. A full understanding of the operation of a device requires that we utilize methods that allow devices or materials to be probed while they are operating (i.e., in situ). This allows, for example, the transformations of the various cell components to be followed under realistic conditions without having to disassemble and take apart the cell. To this end, the application of new in and ex-situ Nuclear Magnetic Resonance (NMR) and diffraction approaches to correlate structure and dynamics with function in materials lithium-ion batteries, supercapacitors and solid oxide fuel cells will be described. The in-situ approach allows processes to be captured, which are very difficult to detect directly by ex-situ methods. For example, we can detect side reactions involving the electrolyte and the electrode materials, and processes that occur during extremely fast charging and discharging. Ex-situ investigations allow more detailed structural studies to be performed to correlate local and long-range structure with performance in both batteries and fuel cell materials.