Collaborative Research: Understanding the Reversible Formation of Sodium Hydrosulfide in Hybrid Electrolytes for High-Energy Density Storage

Northern Illinois University, Dekalb IL

Investigators

Abstract

The development of the high-energy density and low-cost sodium-sulfur (Na/S-NaHS) battery technology can potentially have a transformational impact on the nation’s energy security and critical materials supply chain. This will yield new methods and chemistry understanding to enable the use of this battery system in applications requiring more durability and lower-cost including electric vehicles and grid-scale energy storage for renewable energy generation. This project will enhance partnerships between academia and industry and facilitate the transfer of laboratory inventions to the marketplace. Graduate and undergraduate students will receive research and industry internships training through this project, and students from underrepresented groups will be recruited to participate in this project. A special aspect of this project is the collaboration with Argonne National Laboratory’s Advanced Photon Source for in situ characterization studies and hands-on student training. By characterizing sodium-polysulfide speciation and the electrode process of the battery, this project aims to provide fundamental insights into the multistep phase transformation reaction pathway of the sodium-sulfur chemistry in specific enabling electrolyte systems. By focusing on X-ray scattering characterization of the electrolyte system, this project will help understand the solvation structure evolution of the electrolyte systems at the molecular scale. By focusing on the exchange current density and nucleation and growth rate during electrochemical reactions, this project will enable a better understanding of the Na/S-NaHS electrode reaction kinetics. Together, these studies will advance the knowledge and understanding of the thermodynamics and kinetics of metal-polysulfide electrochemical reactions in various electrolyte systems in both solution and solid precipitation regions. The insight gained here will thus address critical needs in developing the high-energy density battery using abundant materials and lay the foundation for future research in this area. 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.