About the Seminar:

Hybrid halide perovskites (HHP) have garnered interest in materials development in recent years as a result of their facile and inexpensive syntheses, tunable crystal structures, and optical properties. Although HHPs are known for their optoelectronic applications, challenges related to stability and ion-migration have plagued performance. Their high lithium ion-diffusion and energy storage capacity have pushed investigations for their performance as electrodes in alkali-ion batteries. However, due to the soft nature of these materials, their electrochemical degradation pathways and potential for proton evolution must be considered and are not yet well understood. The central question that this research seeks to answer is: How do 2D-HHP anodes transport ions and behave electrochemically in solid-state batteries? We hypothesize that soft nature of these materials may result in degradation pathways (e.g. halide ion migration, proton evolution) that must be considered more thoroughly when trying to understand how HHP electrodes perform. This works seeks to investigate the electrochemical behaviors of a 2D-HHP family of materials,  (BA)2(MA)2Pb3X10 (BA =n-butylammonium, MA = methylammonium), X = Cl, Br, I), in solid-state lithium-ion batteries. We seek to understand how changes in the HHP halide identity affects these processes and solid-state battery performance by focusing ion-transport mechanisms using electrochemical impedance spectroscopy with ion selective electrodes, differential electrochemical mass spectroscopy, and in-operando X-ray techniques. With these methods we will develop a comprehensive understanding of the ion-transport mechanisms and degradation pathways associated with electrochemical performance of the 2D-HHP family (BA)2(MA)2Pb3X10 as electrodes in solid-state lithium-ion batteries. Broadly, this work seeks to address key challenges in nextgeneration energy applications (e.g. energy storage, photovoltaics, hydrogen evolution, etc.) concerning poor electrochemical stability and cycle life, convoluted ion migration and charge transport, and structural tunability of 2D HHPs.