In situ transmission electron microscopy and spectroscopy studies of rechargeable batteries under dynamic operating conditions: A retrospective and perspective view

Since the advent of the transmission electron microscope (TEM), continuing efforts have been made to image material under native and reaction environments that typically involve liquids, gases, and external stimuli. With the advances of aberration-corrected TEM for improving the imaging resolution, steady progress has been made on developing methodologies that allow imaging under dynamic operating conditions, or in situ TEM imaging. The success of in situ TEM imaging is closely associated with advances in microfabrication techniques that enable manipulation of nanoscale objects around the objective lens of the TEM. This study summarizes and highlights recent progress involving in situ TEM studies of energy storage materials, especially rechargeable batteries. The study is organized to cover both the in situ TEM techniques and the scientific discoveries made possible by in situ TEM imaging.