CAREER: Regulating the Interface Chemistry of Sodium Ceramic Electrolytes for Solid-State Sodium Metal Batteries

NON-TECHNICAL SUMMARY

Beyond lithium-ion batteries, sodium-ion batteries show great potential for transportation electrification and large-scale energy storage owing to their analogous battery chemistry, high abundance of sodium sources, low cost of sodium raw materials, and accessibility. Meanwhile, solid-state batteries, which employ nonflammable solid electrolytes to replace the flammable liquid ones, offer a revolutionary solution to mitigate fire hazards that have hobbled the advances of battery technology.

One of the major challenges in the development of high-performance solid-state sodium batteries lies in the large interfacial resistance between the sodium ceramic solid electrolyte and the electrode material. This CAREER award project, jointly supported by the Ceramics program in the Division of Materials Research, and the the Established Program to Stimulate Competitive Research (EPSCoR), addresses the critical interfacial challenges facing between a sodium metal electrode and the sodium ceramic solid electrolyte through regulating the electrolyte surface properties.

The PI and her research group seek fundamental understanding on the interfacial structure-composition-property relationship of the sodium ceramic solid electrolyte. The advancement of scientific knowledge enabled by this research will stimulate the development of solid-state sodium batteries with superior thermal and chemical stability. Such batteries can serve as new alterative low-cost power sources for diverse energy storage applications.

Through this project the PI will promote engagement between local elementary, middle and high school students, undergraduate and graduate students in scientific discourse, particularly in the field of energy materials. The PI will integrate this research into high school AP curriculum and will develop a battery-themed summer workshop, especially for elementary and middle school girls to get hands-on experience for science and engineering projects.

The scientific and educational merits of this project will advance the frontiers of energy storage technologies, promote the diversity in science and engineering research, and tackle the gender gap in STEM fields. TECHNICAL SUMMARY

Among the known solid electrolytes for sodium battery systems, sodium-ion superionic conductor, namely NASICON, is one of the most promising sodium-ion conducting ceramic solid electrolytes owing to its high sodium-ion conductivity and excellent electrochemical and thermal stabilities. Meanwhile, sodium metal is considered as the “holy grail” anode material for sodium batteries because of its low electrochemical potential and high theoretical specific capacity.

However, the pairing of NASICON electrolyte with metallic sodium anode for solid-state sodium batteries gives large NASICON/sodium interfacial resistance and nonuniform dendritic sodium deposition over electrochemical cycling. In this CAREER project, the interface chemistry of NASICON will be regulated by a variety of ultrathin metal oxide coatings via atomic layer deposition.

This research will investigate the hypothesis that the composition, crystallinity, morphology, and microstructure of the oxide coating on NASICON play critical roles in the early-stage electrochemical wettability of sodium metal and the sodium-ion transport across the interface, which affect the interfacial impedance, the sodium nucleation/growth process, and the electrochemical characteristics. This research can take a leap beyond the lithium technology by utilizing the much more sustainable, natural abundant and low-cost sodium resources.

The reduced cost of sodium batteries compared to the lithium systems will make them highly desirable for large-scale energy storage application. The PI will integrate this research program into a variety of educational and outreach activities to broadly disseminate the knowledge/research findings, to promote the diversity in engineering research, and to tackle the gender gap in STEM fields.

The education components mainly include the following aspects: (1) incorporating this research into teaching by developing new course curriculums and research projects for undergraduate and graduate students; (2) integrating this research into local high school AP curriculum; (3) developing summer workshop “Battery Wonderland” for elementary and middle school girls to get hands-on experience for science and engineering projects.

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.