Our ability to store electrical energy is necessary to enable the use of intermittent renewable energy such as wind and solar. Yet, resource scarcity threatens our ability to meet energy storage needs. While lithium-ion batteries and platinum-based fuel cell catalysts continue to be the commercial standard for their respective technologies, the cost and demand for elements such as lithium, cobalt, nickel, and platinum continue to limit large-scale deployment. As such, there has been a solid push to explore other chemistries that rely on more abundant elements. However, these differing chemistries come with technological challenges that require a deeper understanding of how the materials function under operating conditions. Here, I present the operando X-ray characterization of sodium-ion layered cathodes and an Mn-Co oxide fuel cell catalyst. First, I show how operando single-particle X-ray diffraction reveals new understandings of structural phase transitions in a sodium-ion cathode during charge. Second, I show how Bragg coherent diffractive imaging can reveal micro-strain dynamics and dislocations in a sodium-ion cathode. Finally, I show how coexisting structural phases exhibit different oxidation state behaviors and induce micro-strain in an Mn-Co oxide fuel cell catalyst using resonant elastic X-ray scattering. These findings not only contribute to our understanding of the fundamental properties of these dynamic materials but also provide crucial insights that can inform the design of next-generation energy storage materials.