SBIR Phase I: Electrolyte and Interphase Design for Stable, Safe, and Low-Cost Sodium Batteries

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase I project is an economical solution to achieving sodium-ion batteries that meet the performance requirements for grid energy storage systems with 2- to 8-hour duration. Sodium-ion batteries are not yet ready for grid applications due to limitations around battery lifetime, especially calendar lifetime and temperature stability, which is the key problem that this project will address using a low-cost electrolyte that is designed specifically for sodium-ion batteries. The global market for sodium-ion batteries for grid applications is projected at $4.1-8.2 billion by 2030, and is projected to grow rapidly through 2050 and beyond. A solution to the sodium-ion battery lifetime challenge will position the United States as a global leader in the nascent but rapidly-growing market, which is expected to yield significant economic and job development. Moreover, this innovation will enhance the scientific understanding of sodium-ion battery electrolyte and interphase chemistry, providing an enabling solution for the sodium-ion market as a whole. The intellectual merit of this project is centered on the development of electrolyte and interphase chemistries specifically tailored to the requirements of sodium-ion battery chemistry, which varies in several ways from the more mature lithium-ion battery chemistry. These novel and tailored electrolyte chemistries will provide a drop-in solution to the cycle and calendar life challenges, while achieving low-costs via an innovative and simple synthesis process. Moreover, this electrolyte chemistry has shown promise as a fire-extinguishing liquid, which may drive substantial safety improvements for large grid applications where fires are a significant concern. The primary objectives of this project are enabling this synthesis process to achieve high electrolyte quality, rationally designing the electrolyte formulation for a specific sodium-ion battery cell design that is most interesting for grid applications, and validating the combination of these breakthrough innovations in prototype battery cells that are of interest to grid energy storage system customers. This project will demonstrate the synthesis process for an optimized electrolyte chemistry and full cell performance results at a commercially-relevant scale to validate the commercial viability of these innovations at a suitable level to attract follow-on investment. 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.