CAREER: Multi-dimensional synthetic approach toward alkali-transition metal intermetallics guided by theory and in-situ studies

Iowa State University, Ames IA

Investigators

Abstract

Non-technical summary: Material synthesis and discovery has enabled current technological advances, such as lithium-ion batteries, solar cells, smartphones, microprocessors, medical imaging, and turbines for harnessing wind energy. Despite significant progress in material synthesis, there are many compounds that remain inaccessible by standard synthetic routes. For instance, synthesis of compounds containing ductile and soft alkali metals and powdery non-metals is challenging. Researchers encounter issues with reactants mixing, similar to mixing chocolate chips and cookie dough. With this CAREER award project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, the principle investigator and her research group develop unique synthetic pathways by utilizing innovative salt-like starting materials. The synthesis is guided by real-time reaction monitoring and theoretical predictions. This approach yields unique alkali metal compounds with potentially useful properties for energy conversion and storage. Additionally, as an education aspect, the PI promotes dissemination of scientific results to the general public, facilitates involvement of undergraduate students into research, and assists graduate students with their job search through video tutorials. These short educational, yet entertaining videos are created as part of the new ICON program (Iowa Chemistry Outreach Network). Technical summary: This CAREER award project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, advances a synergistic theoretical-experimental synthetic approach to a high level of complexity by aiming at ternary systems with distinctly dissimilar reactivities of elements, such as highly reactive and volatile alkali metals A, refractory and kinetically sluggish transition metals M, and p-block element E. Until now the phase spaces of such systems have remained essentially unexplored, in a stark contrast with similar R-M-E ternary systems (R = rare-earth metal). From the synthetic point of view, elemental alkali metals are challenging precursors. Because of their ductility, volatility, and reactivity, homogeneous mixing of metal/metalloid reactants involving an alkali metal is difficult, while traditional high-temperature treatments, such as arc-melting, are not applicable. This comprehensive experimental approach utilizes salt-like mixable alkali metal hydrides as precursors and is coupled with in-situ reaction monitoring by variable temperature X-ray diffraction and theoretical predictions of structure stability. The research objectives include the targeted and controlled preparation of new ternary compounds, which are unavailable by standard solid state chemistry routes, paving a way to solid state synthesis by design. This research project contributes to the basic knowledge in the field of solid state and materials chemistry, in line with the NSF-DMR program mission. Additionally, as an education aspect, the PI promotes dissemination of scientific results to the general public, facilitates involvement of undergraduate students into research, and assists graduate students in their job search through video tutorials. These short educational, yet entertaining videos are created as part of the new ICON program (Iowa Chemistry Outreach Network). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.