This CAREER award supports integrated research, educational activities, and outreach initiatives focused on utilizing computer simulations to advance the fundamental understanding of the movement of ions at interfaces in oxide heterostructures. In solids, this ionic movement offers the basis of operation for electrochemical energy conversion and storage technologies.
Oxide heterostructures are an intriguing class of nanomaterials created by joining two dissimilar oxides that are significantly smaller than the width of a human hair. As a whole, they exhibit superior properties than their individual constituents, and they are responsible for novel applications in numerous nanoscale energy technologies. A vital application of oxide heterostructures is their use as solid oxide fuel cell electrolytes, which facilitate easy passage of oxygen ions for generating electricity in the cell. At these electrolyte interfaces, crystallographic imperfections known as "misfit dislocations" are formed to alleviate the strain that would otherwise arise when joining two materials with dissimilar sizes. Misfit dislocations at interfaces of oxide heterostructures are often held accountable for behaving as pathways for oxygen ion transport. However, standard approaches cannot predict if misfit dislocations enable faster movement of ions or slow them down.
This research aims to develop advanced theoretical and computational tools to understand the fundamental ionic transport mechanisms at misfit dislocations. Various computer models will be implemented to trace the motion of ions and predict the fundamental atomic scale factors that lead to either faster or slower movement of ions across oxide interfaces. This basic knowledge will be instrumental for designing fuel cell electrolytes based on advanced oxide heterostructures that exhibit enhanced rate of ion mobility and thus better performance. The computational framework developed in this research will serve as a paradigm for future design of superior electrolytes and accelerate the use of environmentally friendly solid oxide fuel cell technology.
The research component of this project will be tightly integrated with the educational activities to increase public awareness regarding alternative energy resources and their benefits to the society. This project will train the next-generation renewable energy workforce by offering interdisciplinary training to graduate and undergraduate students. Students will receive opportunities to visit national laboratories to gain valuable experience in modeling of energy materials and broaden their horizons. Female and minority students will be recruited to engage in renewable energy research, thus promoting underrepresented communities in science and engineering by providing pathways into and retention in advanced degrees. Research output will be used to develop undergraduate and graduate coursework, and short courses and simplified computer demos for K-12 students, thus reaching a broader pool of students interested in energy research. The computational tools developed in this project will be made accessible to the scientific community as open source software.
This CAREER award supports integrated research, educational activities, and outreach initiatives focused on developing a multiscale computational framework to advance the fundamental understanding of ionic transport mechanisms across interfaces in oxide heterostructures.
Oxide heterostructures, an intriguing class of nanomaterials fabricated by joining two dissimilar oxides, have numerous applications in a wide range of energy technologies. An important application of oxide heterostructures is their use as solid oxide fuel cell electrolytes. The research component of this project is motivated by experimental observations: Several experiments report that misfit dislocations ubiquitous at interfaces of mismatched oxide heterostructures enhance ionic transport, while some experiments suggest that they slow down ionic transport. Conventional approaches cannot predict the atomistic origin for this enhancement or impediment since the basic atomistic mechanisms governing ionic transport at misfit dislocations are not well understood.
The objective of this research is to elucidate the fundamental ionic transport mechanisms at misfit dislocations by studying their intricate interaction with point defects and dopants. The principal hypothesis is that the fundamental nearest neighbor model of defect diffusion will come into play at misfit dislocations. The PI and his team will build a novel multiscale framework that integrates density functional theory and molecular dynamics to study defect thermodynamics with a new kinetic lattice Monte Carlo model to study defect kinetics at misfit dislocations. This multiscale framework will assist in establishing the basic connection between misfit dislocation structure and functionality. The research will advance the state of knowledge pertaining to the crucial role of interfaces and extended defects in shaping new functionalities of oxide heterostructures. The fundamental science thus unraveled will offer strategies to ultimately control the impact of misfit dislocations and guide future design and synthesis of next-generation solid oxide fuel cell electrolytes.
The research component of this project will be tightly integrated with the educational activities to increase public awareness regarding alternative energy resources and their benefits to the society. This project will train the next-generation renewable energy workforce by offering interdisciplinary training to graduate and undergraduate students. Students will receive opportunities to visit national laboratories to gain valuable experience in modeling of energy materials and broaden their horizons. Female and minority students will be recruited to engage in renewable energy research, thus promoting underrepresented communities in science and engineering by providing pathways into and retention in advanced degrees. Research output will be used to develop undergraduate and graduate coursework, and short courses and simplified computer demos for K-12 students, thus reaching a broader pool of students interested in energy research. The computational tools developed in this project will be made accessible to the scientific community as open source software.
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.
