Control of microstructure, internal dynamics and chemistry is of primary importance in determining the performance and viability of solid oxide fuel cells, hydrogen fuel cells, carbon capture materials, and other systems that advance the hydrogen economy, promote US energy independence, or simply advance the Nation’s industry, e.g., through Additive Manufacturing. The relevant scale range for void and phase microstructure (e.g. interfacial morphology, sintering or annealing), as well as for chemical site reactivity (e.g., combustion, reforming, corrosion) extends from the micrometer down to the sub-nanometer scale regime. Our goal is to develop in operando measurement methods to quantify full three-dimensional void and phase microstructures and dynamics, including changes during service life and dependence on processing conditions. These issues apply, e.g., to the electrodes and electrolyte of a SOFC; to the interfaces between them; and to any separate fuel-reforming hydrogen storage, or carbon dioxide capture material, where the microstructure must be related to the reaction site kinetics and to changes in site reactivity during service life. This opportunity will address these interconnected issues by utilizing unique instrumentation, developed by NIST and its collaborators, and located at the Advanced Photon Source, the National Synchrotron Light Source II, and the NIST Center for Neutron Research. Opportunities exist for investigating novel energy materials and devices including batteries, solid oxide fuel cells, energy harvesting devices, photovoltaics, and additive manufactured components.