| Abstract Scope |
As batteries are employed in larger numbers and for increasingly diverse applications, there is interest in electrode materials with improved safety, availability, and cost relative commercialized electrodes. Early transition metal oxides are one alternative material family showing promising, especially for high rate applications. However, we don’t have a strong understanding of the role of composition, structure, and structural evolution with cycling for these materials, which tend to have large unit cells and complex structures. Motivated by this fundamental understanding, we report the study of related complex niobate electrode materials KNb3O8 and NaNb3O8. Using ex situ and operando X-ray diffraction and pair distribution function analysis, we identify local and average structure changes and relate them to cycling performance, as well as to other early transition metal oxides with compelling performance. This fundamental understanding is a necessary step toward the selection and design of electrode materials for the quickly evolving energy landscape. |