Economic growth and population expansion have led to a rapid increase in energy consumption, intensifying the need for electrical energy storage (e.g., battery) technologies. Lithium-ion batteries are battery technologies having promise in more applications, e.g. in providing high energy and high power in electric vehicles or electrical grids. Recent studies have observed that lithium-ion battery electrode materials (such as TiO2) contain intentional structural defects exhibit enhanced electrochemical charge storage capacity. This project uses irradiation to introduce defects into TiO2 nanostructured electrodes, because irradiation is known to produce an excess of defects in a material. Confirmation of the hypothesis of enhancing battery functionality using irradiation could promote the use of intentional structural defects to profoundly transform battery research, fabrication, and applications. This project may also lead to improved battery functionality through in-service, in situ irradiation in applications subject to high radiation fields, such as satellites and high-altitude aircraft; advanced sensors for security, defense, and power production; remote warfare; nuclear energy and propulsion; and healthcare. Integrated research and education activities will have impacts on undergraduate and graduate students, as well as the general public.
TECHNICAL DETAILS: The objective of this project is to determine how and by what mechanisms irradiation affects the electrochemical charge storage of nanostructured TiO2 electrodes. The project addresses the foundational science of the behavior of rechargeable battery systems under irradiation. There is currently limited knowledge of the fundamental mechanisms of irradiation effects on charge storage properties of metal oxide electrodes. This research is filling a knowledge gap in intercalation kinetics and structural evolution of metal oxide electrodes under irradiation. Studies suggest structural defects in metal oxides can enhance the material's electrochemical charge storage capacity. Since irradiation is known to produce an excess of point defects in a material, it is hypothesized that irradiation can similarly enhance the charge capacity of metal oxide electrodes. In this project, crystalline TiO2 nanotubes are proton irradiated, then undergo electrochemical cycling with Li. Recent advances in characterization techniques enable the observation of defects and nanostructure following electrochemical cycling. This project integrates experiment and modeling to obtain a fundamental understanding of irradiation effects on charge transport and structural evolution of metal oxide electrodes. Graduate student researchers are gaining technical experience with cutting-edge research equipment and techniques and working in collaboration with national laboratories. Undergraduate student researchers from the Boise State Louis Stokes Alliance for Minority Participation program are also involved. Topics from this project are being used for curriculum development and outreach programs to middle and high schools.
