Revealing Dynamic Transformations of Materials using in situ Scanning Transmission Electron Microscopy

Recent advances in the development and implementation of microfabricated platforms for in situ/operando liquid S/TEM experimentation have resulted in new research opportunities in the physical sciences, where it is now feasible to image dynamic chemical and electrochemical processes within their native liquid environment, at high spatial resolution and under external stimuli. In the first part of the talk, I will focus on interpreting electron beam induced radiolytic transformation of materials from organometallic precursor electrolytes as it relates to nanocrystal nucleation and growth mechanisms of metallic and bi-metallic systems. From a data analytics approach, we quantify nucleation and growth rates as a function of electron dose and utilize this information to elucidate growth mechanisms. This will transition into the second part of the talk, which will focus on the in situ electrochemistry aspect of liquid cell microscopy where I will show how this method is used to elucidate the fundamentals of electronucleation and how by actively controlling diffusion-controlled growth, the transformation kinetics can be tuned to control size, shape, and morphology of nanocrystals. Then I’ll show how this approach can be utilized for energy storage research to probe the mechanisms and kinetics of solid electrolyte interphase formation and Li electrodeposition in batteries and ionic transport in supercapacitors. The information obtained from these studies can help provide a deeper understanding of materials transformations.