Speaker
Description
The energy transition relies on materials with complex and dynamic interfaces involving low atomic weight and mobile liquid, solid, and gaseous species. Understanding the chemistry, phase, and morphology of these interfaces at high-resolution length scales is crucial for optimising their behaviour and performance. However, existing high-resolution imaging and characterisation techniques struggle to capture dynamic solid-liquid interfaces at atomic resolutions, leading to poor understandings of key electrochemical phenomena like solid-electrolyte interphase (SEI) formation.
While various techniques have been applied to study such interfaces, none alone can provide the necessary dynamic and atomic level resolution to fully understand and characterise these types of complex systems at high resolutions. Liquid-cell transmission electron microscopy (LCTEM) offers real-time imaging of dynamic electrochemical processes at high temporal and spatial resolution but is limited by sample thickness and beam-induced effects. On the other hand, cryogenic microscopy, such as cryogenic Atom Probe Tomography (Cryo APT), enables 3D compositional reconstructions of frozen nanoscale volumes with sub-nanometre spatial resolution and ppm-level chemical sensitivity for all elements. Cryogenic microscopy techniques are however only capable of offering a snapshot of a particular system when a full dynamic understanding is required. This makes dynamic liquid microscopy techniques and high-resolution cryogenic microscopy techniques extremely complimentary.
This work successfully combines operando LCTEM with Cryo APT through the use of an inert glovebox, cryogenic PFIB/SEM, and vacuum cryo transfer module (VCTM) technology. This integrated approach enables dynamic sub-nanometre compositional analysis of electrochemical phenomena in lithium-based battery systems. By combining the strengths of liquid microscopy for real-time observation and cryogenic techniques for high-resolution compositional analysis, this method provides unprecedented insights into early-stage Li plating, intercalation, dendrite growth, and SEI formation. This approach marks a significant advancement in understanding and optimising dynamic electrochemical systems critical to energy technologies.
