Next generation Li-ion batteries with higher energy densities, better safety characteristics, lower cost and longer cycle life holds enormous potential for electric transportation, renewable energy storage and emerging techniques such as the Internet of Things (IoT). One technical barrier to the continued improvement of battery performance is the insufficient understanding of the electrolyte decomposition and deposition on the electrode surface. This stems from a lack of chemical analysis tools to monitor the molecular interactions at the electrolyte/electrode interface during the reaction. In this project, the investigators will develop a high-performance platform to probe in real-time the evolution of chemical signatures at electrolyte/electrode interface. The new technology will be used to investigate the interface reaction mechanism of promising new electrode materials for safer, lighter and higher capacity Li-ion batteries. It will also benefit other chemical and electrochemical systems where real-time chemical analysis is crucial in elucidating reaction mechanisms and improving performance. Furthermore, the project team will engage the historically underrepresented Inland Empire community in educational and outreach activities aiming at increasing diversity in science and engineering higher education, which accompanies NSF Strategic Plan for 2018-2022 by preparing and engaging a diverse U.S. STEM workforce.
The technical goal of this project is to develop a stable and high-performance electrochemical operando surface-enhanced Raman spectroscopy (SERS) technique to study the electrochemical interfaces in next-generation lithium-ion (Li-ion) rechargeable batteries. The proposed technique will address the critical needs for operando spectroscopic tools to understand the interfacial reactions at the electrolyte/electrode interface and the formation mechanism of interfacial species. The PIs will employ a unique design of large-area close-packed films of (electro)chemically-robust Ag@Au epitaxial core-shell nanocubes (NC) as the SERS substrate, that offers for high, homogeneous and stable signal enhancement for operando chemical analysis of electrochemical interfaces. Two major task are planned: (1) synthesize and assemble the Ag@Au epitaxial core-shell nanocubes for large-area high-enhancement SERS substrates, and validate/optimize the operando SERS platform by investigating the carbon/electrolyte interface with known interfacial compounds; and (2) apply the optimized operando SERS platform to study the electrode/electrolyte interfaces of two novel electrode materials including sulfur and silicon.
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.
