Influence of the Host-Solvent Interface on Intercalation Reactions in Layered Solids

University Of Florida, Gainesville FL

Investigators

Abstract

NON-TECHNICAL SUMMARY Solids with internal structure composed of chemically bonded layers separated by weaker interactions form the basis of important technologies, especially in areas of energy storage. Modern batteries use layered materials as the chemically active components that store and release ions during operation. Layered solids are also being developed by materials scientists and engineers for next-generation semiconductor devices. For many of these applications, smaller particles improve performance, but as particle size decreases, surfaces contribute more and more to material properties. Supported by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, this project explores how the surface contribution to solid-state properties changes when the layered solids operate in different chemical environments, specifically when used in different solvents. Combining experimental and computational approaches, the fundamental studies will directly inform applications that rely on chemical reactions of layered solids, including applications in critical energy-related and information technologies. Through research tasks designed to be platforms for training and development, the project will provide students with the skills and knowledge needed to be competitive in high-technology professions. TECHNICAL SUMMARY Intercalated layered solids are among the most widely used in current lithium electrode technologies and among the most widely explored for future solutions. Other important applications involving layered host/guest reactions include catalysts, ion exchange and the production of 2D materials. Although it is widely recognized that solvents play crucial roles in liquid phase intercalation processes, the reasons behind much solvent-dependent behavior remain poorly understood and under debate. This NSF SSMC project combines experimental and computational approaches to quantify how the solvent-host interface alters the effective internal pressure of the host as surface energy and surface stress change, leading to differences in chemistry. Using molecular intercalation reactions, research aims include detailed structural analyses of solvent-host interactions alone; structural and kinetic studies of solvent influences on intercalation products and mechanism; and theoretical studies to relate the solvent-host effects to key mechanistic steps in the intercalation process. Findings will directly inform applications that rely on solid-state host-guest reactions, including applications in critical energy-related and information technologies, and the project includes significant human resources development, providing training and knowledge needed to be competitive in high-technology professions. A new public outreach exhibit, entitled The Materials in Your Battery, will highlight fundamental questions related to battery technology. 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.