Acoustic Modification of Crystallization and Dislocation Dynamics in Energy Materials to Reduce Carbon-Intensity

Mariana I. Bertoni, Arizona State University (Principal Investigator)

David P. Fenning, University of California San Diego (Co-investigator)

Nasim Alem, Pennsylvania State University (Co-investigator)

Structural defects determine the functionality and durability of many energy materials, yet the defect density is exquisitely sensitive to manufacturing process conditions. The ability to understand and control the nucleation and propagation of structural defects is key to manufacturing of high-performance energy materials. Solution-based sonochemistry has long been studied as a way to overcome the stochastic nature of crystallization and control crystal size, distribution, morphology and chirality in the chemical and pharmaceutical industry. However, to date, the application of ultrasound to create large shear stresses relevant to forming or other manufacturing processes is well-established only in ductile metals.

This project will systematically investigate the use of high-intensity ultrasound as a potentially transformative manufacturing approach to improve the crystal quality of a wide range of energy materials, as an alternative to, or synergistic with, traditional thermal annealing. A principal focus will be on the application of high-intensity ultrasound to soft crystalline lattices, characteristic of many chalcogenide and halide crystals. Their very softness in part contributes to their varied functionality and energy applications, e.g., as polarizable semiconductors and fast ion conductors of relevance to many emerging energy technologies.

Through a combination of advanced automated manufacturing and characterization tools, such as transmission electron microscopy, in-situ Raman micro-spectroscopy, and nano-diffraction, the project team proposes to elucidate the fundamentals of ultrasound-assisted thin film transformations, where power, frequency and time can control the kinetics and thermodynamics of a system. Answers to these questions could seed a rich new field of study in synthesis and fabrication science, creating hyper dimensional transformation diagrams (for example concentration, temperature, frequency, power, time), and enabling transformative manufacturing processes capable of high-quality crystals and possible forming of materials and their interfaces using energy-efficient, low temperature processes.