High energy density and cycling stability of lithium-based batteries are receiving great attention as they have become essential for everyday life, from portable devices to Electric Vehicles(EVs). Charging/discharging of the cell inevitably accompanies dynamic changes such as nucleation and growth of Li, phase transition of cathode materials, and Solid-Electrolyte Interphase (SEI) formation, which are closely related to the electrochemical performance.
Our research focuses on directly visualizing such changes of materials in battery systems, from which we can obtain fundamental knowledge for improving the stability of the LIB systems. In situ transmission electron microscopy (TEM) enables direct observation of nanoscale dynamics in battery systems by providing chemical and crystallographic information of component materials. We investigate various phenomena in battery systems including synthesis of electrode material, (dis)charging, and thermal effect by using in situ Liquid-Phase TEM (LPTEM), in situ biasing/heating TEM and cryo-TEM, with a combination of bulk in situ characterization methods such as in situ XRD and in situ Raman.