NSF Award
2431248
Halide ion-based electrochemical charge storage systems are attracting immense attention due to their high theoretical energy densities, low flammability and low risk of metal dendrite formation, the promise of local component sourcing, and their unique utility as biocompatible power sources. Polymer-based electrodes and electrolytes have the potential to yield high energy density halide ion batteries, however these polymer materials are in their infancy, and design guidelines to create optimal materials are currently unknown. The goal of this project is to apply the polymer growth and vapor-processing advancements made in investigator's lab to develop competitive polymer electrodes and electrolytes for halide ion batteries. This work will produce experimentally validated guidelines for optimal polymer electrode and electrolyte materials that will broadly inform materials and device development endeavors in the electrochemical systems community. This project will provide education and training to graduate students engaged in Ph.D. research, undergraduates gaining their first research experiences, and community college students participating in an internship program that increases opportunities for minority and first-generation researchers in STEM fields.<br/> <br/>In their present iteration, polymer-based electrodes and electrolytes have not yet afforded sufficiently high chloride storage densities and conductivities, and design rules for accessing optimal materials have not been established. The overarching hypothesis of this effort is that the real-time composition, morphology and porosity control afforded by polymer chemical vapor deposition (CVD) will yield conductive polymer electrodes with a high volumetric density of accessible chloride-storage sites and halide-conducting gel/membrane electrolytes with high ionic conductivities. Different facets of this hypothesis are explored in each aim: (1) the advantage of using oxidative chemical vapor deposition (oCVD) to create thick and conductive chloride-storing electrodes with high volumetric chloride storage capacities is explored; (2) the ability of the photoinitiated chemical vapor deposition (piCVD) process to create gel and solid-membrane electrolytes with high chloride conductivity via controlled mesh sizes will be experimentally proven; (3) the compatibility of the reaction trajectories/deposition chemistries used in oCVD and piCVD with fluoride anion salts will be explored to develop materials for fluoride-ion batteries. The project plans span process research, and thin-film and electrochemical characterization efforts, complemented and accelerated by collaborative efforts to apply machine learning algorithms to predict competitive electrode structures.<br/><br/>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.
