In-situ transmission electron microscopy characterization of electrochemical processes in solid-state energy storage devices with air sensitive materials

Fundamental scientific advances are needed to create breakthrough materials that will improve the performance of electrical and energy storage devices. Over the last decade in- situ transmission electron microscopy (TEM) has been used to characterize these materials in devices at resolutions down to the atomic level. Importantly, this can also be done in-situ while the devices are operating. This allow direct correlations to be made between material structure and device performance. However, for materials that are sensitive to air-exposure – e.g. Li battery materials, where exposure to air for even a few seconds can significantly affect material structure and chemistry – researchers currently do not have an adequate solution to transfer samples from a protective preparation environment (e.g. a glove box) into the TEM for in-situ electrical experiments without exposing the samples to air. As a result, any of these experiments could be questioned on the basis that it is not known what the effect of air-exposure is on the materials that are being characterized. In Phase I of this project we solved this challenge by developing a prototype in-situ TEM air-free transfer biasing sample holder enabling in-situ TEM biasing and heating experiments on air- sensitive materials. We also developed an air-free transfer holder for imaging of standard TEM grids. In Phase II of this project we will develop double-tilt configurations of both these transfer holders, develop configurations to fit all modern TEM models, develop a transfer tool for sample preparation in the Focused Ion Beam (FIB), productize the TEM holders and support tools, and bringing the TEM holder suite to market. This TEM vacuum/inert-gas transfer electrical biasing and heating specimen holder will allow routine imaging of the nanoscale physics and chemistry occurring within operating electronic and energy storage devices, while at the same time allowing air-free transfer of the sample into the TEM. The broader impact/commercial potential of this project will be that when it will enable air-free transfer into the TEM for performing in-situ biasing TEM experiments. This will allow researchers and technologists to rapidly advance the fundamental understanding of the processes governing material performance and make better-informed decisions regarding optimum materials and designs. This will accelerate the manufacture of next generation energy storage and electronic device technologies. The issue of air-free handling is very important especially in the areas of catalysis and energy storage materials, because of the sensitivity that these materials display to exposure to oxygen or moisture. Furthermore, many of the nanoscale semiconductor systems have a high sensitivity to oxygen as it dopes the structures or changes the defect density.