CAREER: Synthesis of Compositionally Complex Oxides for Energy Conversion and Storage

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

TECHNICAL SUMMARY This research supported by the Solid State and Materials Chemistry program will generate new solid state materials that will advance the basic chemistry of solar energy conversion and electrical energy storage. In solar energy conversion, the focus is on synthesizing complex (mixed-metal) compositions of transition-metal tungstates in specific morphologies that will maximize light absorption and charge-carrier collection to photocatalyze water oxidation. The synthesis methods for metal tungstates that will be developed include electrochemical deposition, sol-gel processing from colloidal suspensions, hydrothermal synthesis, and spray pyrolysis from aqueous precursors. Potential-pH (Pourbaix) diagrams from aqueous inorganic reaction chemistry guide the choice of synthesis precursors and reaction conditions to generate the desired compositions. Then, with new compounds in hand, the propensity to carry out photocatalysis will be probed by standard photoelectrochemical methods. In electrical energy storage, these synthesis methods will be applied for creating high specific power nanomaterials with high specific energy material for lithium-ion storage. Reactions can be combined in sequential steps to give mixed-metal spinel-structured materials for stable Li-ion electrodes. With these compounds, battery performance will be tested by standard electrochemical methods. Then, coatings that enhance carrier separation in photocatalysts and the stability of the battery materials can be added by pyrolysis (during synthesis) or by photochemical deposition (in a post-synthesis modification step). NON-TECHNICAL SUMMARY Solid-state materials are at the forefront of renewable energy science. This grant supported by the Solid State and Materials Chemistry program directly addresses challenges in solar energy conversion to generate chemical fuels from sunlight and electrical energy storage to have energy available at any time of day. These problems will continue dominate national science and technology discussions for the foreseeable future. Because this science is applied to big problems in energy, there is a pressing need to include young scientists to secure a strong and diverse talent pool for the future. Accordingly, this program has a strong educational outreach initiative in collaboration with the highly successful Young Scientist Program (YSP) at the Washington University School of Medicine. YSP brings high-school juniors, preferably from groups historically under-represented in the chemical sciences, into the laboratory for ten weeks during the summer and begin working with a team of researchers. Important for securing long-term impact, the relationship between the high school student, a graduate mentor, a graduate tutor, and the PI will commence during the spring term prior to starting laboratory research, and it will continue through the college admissions process. A second goal of this outreach is to share research findings and laboratory experiences with students' peers using internet social networking.