Chemical imaging entails fundamental and use-inspired research aimed at understanding the spatially distinct chemical and physical makeup and dynamic processes ongoing at solid-solid, solid-liquid, and solid-gas interfaces. Detailed chemical and physical understanding of such interfaces is central to pushing forward major advances in areas like photovoltaic cells, energy storage, fuel cells and catalysis, among others, that are critical in the DOE energy research and national security missions.
For example, the presence of the solid-electrolyte interphase (SEI) that forms on the electrode surfaces of lithium-ion batteries plays an essential, but poorly understood, role in the battery performance. Through selectively probing the electrode/SEI and SEI/electrolyte interfaces with scanning probe microscopy, mass spectrometry, and nonlinear optical imaging based on coherent vibrational sum-frequency generation, a detailed knowledge of the spatial distribution of the elemental and organic constituents of the SEI film, and their variations during the course of the charge-discharge cycles, can be obtained.
ORNL researchers take a multi-tiered approach to chemical imaging that includes ultrafast optical spectroscopy and microscopy, scanning probe microscopy, and surface sampling and ionization processes in combination with mass spectrometry detection. New techniques and tools are used to study and characterize interfaces with the ability to specifically detect or identify a wide range of elements, molecular compounds from small molecules to large macromolecules, and functional domains, over a variety of time scales.
The overarching goal of ORNL's chemical imaging program is to transcend the existing analytical capability for nanometer scale spatially resolved material characterization at interfaces through a unique merger of advanced spectroscopic and ultrafast time-resolved imaging, scanning probe microscopy, and mass spectrometry.
For more information, contact: