Collaborative Research: Sodiation Driven Multiscale Chemical-Structural Interactions in Alloy Electrodes

University Of Alabama In Huntsville, Huntsville AL

Investigators

Abstract

There is a critical need to dramatically increase the integration of renewable energy in the electric grid. The inherently intermittent and diffuse nature of these renewable resources predicates the development of cost-effective, large-scale energy storage. Such storage capabilities offer the added benefit of contributing resilience to the electric grid, which is needed to mitigate the effects of natural disasters and other catastrophic events. Electrochemical energy storage technologies based on earth abundant and cost-effective materials are increasingly needed. The sodium ion battery and tin (Sn) based alloy anode materials are promising technologies for this application that needs high-capacity energy storage. Through this fundamental research project, stronger connection is made between the chemical and structural changes due to sodium storage in Sn-based alloys and the resulting performance of the sodium ion battery. The research project contributes to the education and training of both graduate and undergraduate students within a multidisciplinary research environment. The integrated education and outreach plan will create opportunities for graduate, undergraduate, and high school students to be involved in this research and places a strong emphasis on increasing the participation of students from underrepresented groups. Research findings will be integrated into the curriculum at the undergraduate and graduate level through lectures and laboratory classes. A library of open-source data generated from the comprehensive experiment, characterization, and simulation efforts will lead to the advancement of energy storage science. By facilitating the future development of sodium ion batteries, the project will help contribute to the societal need for cost-effective grid energy storage. The principal objective of this research is to develop a comprehensive knowledge base and understanding of the chemical and structural transformations in high-capacity tin (Sn) based alloy electrodes for sodium ion batteries. This work is predicated on the hypothesis that changes in mesoscale morphology and chemical composition caused by sodiation contribute significantly to the irreversible capacity of such alloy electrodes. An experimental program including electrochemical testing, X-ray diffraction characterization of electrode crystal structure, and in operando X-ray tomography will be coupled with mesoscale computational studies of sodium ion battery electrode microstructures. This comprehensive research approach will test the above hypothesis by achieving these research objectives: (1) correlate changes in Sn-based alloy electrode crystal structure with electrochemical performance; (2) correlate multiscale alloy electrode morphology with structural and chemical changes; and (3) clarify the influence of electrode microstructure on the transport-electrochemistry interaction and performance. The research will provide insight into the interactions between microstructure, chemistry, and performance in sodium ion batteries. The combined experimental and computational approach will provide unprecedented details on the chemical and structural evolution of alloy electrodes due to sodiation. The insights gained will facilitate engineering of future sodium ion battery electrodes and will yield methods applicable to an array of electrode materials relevant to other battery chemistries. The proposed X-ray imaging and mesoscale modeling efforts will yield a documented set of 3D microstructural data, which will be disseminated through an open-source platform and will support future research and development. 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.