MateriAlZ Seminar: Annalise Maughan
Friday, February 23, 2024 - 11 a.m. MST
Annalise Maughan
Assistant Professor
Department of Chemistry
Colorado School of Mines
"Site Disorder Drives Cyanide Dynamics and Fast Ion Transport in Li6PS5CN"
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Abstract
All-solid-state batteries hold the potential to transform electrochemical energy storage technologies. Replacing the flammable liquid electrolyte with a solid-state ion conductor can improve battery safety and may further increase battery energy density when paired with lithium metal anodes. The halide argyrodites Li6PS5X (X = halide, pseudohalide) are a promising family of candidate solid electrolytes, as they can achieve ionic conductivities that are nearly competitive with liquid electrolytes. In this work, we have discovered the new solid electrolyte Li6PS5CN in which the halide site is occupied by the orientationally-disordered cyanide ion. The new cyanide argyrodite exhibits lower activation barriers for Li-ion conductivity compared to the current champion argyrodite Li6PS5Br and comparable room temperature lithium-ion conductivities. Structurally, the similar sizes of cyanide and bromide ions produce nearly identical lithium conduction pathways. We further unravel the connections between static and dynamic disorder of cyanide and the subsequent impact on ion transport processes in Li6PS5CN. Through this study, we find that anion disorder plays a decisive role in dictating the extent and timescales of both lithium and cyanide dynamics in Li6PS5CN.
Bio
Dr. Annalise Maughan is an assistant professor in the Department of Chemistry at Colorado School of Mines and holds a joint appointment with the National Renewable Energy Laboratory. She received her BS in chemistry and a minor in mathematics from Northern Arizona University and her PhD in chemistry from Colorado State University. She then joined NREL as a director’s postdoctoral fellow prior to joining Colorado School of Mines. Her research is focused on solid-state materials for renewable energy, with an emphasis on understanding the design principles that connect chemistry, local and long-range structure and dynamics to functional properties such as charge transport and light absorption/emission.