An Introduction to Full Field, Hard X-Ray Microscopy Beamline at Brookhaven: 2D/3D, Ex Situ/in Situ Studies for Energy Materials
Authors: Wang Jiajun , Eng Christopher , Chen-Wiegart Yuchen , Wang Jun 
Published: February 2020

In developing new electrode materials for clean energy systems, it is critical to understand the fundamental reactions occurring inside the electrode materials and observe the morphology/structural evolution during the operation of the energy systems. Among of various imaging technologies, hard X-ray imaging is of great interest for applications in energy materials studies because it is non-destructive, chemically and elementally sensitive, environmentally friendly (ambient atmosphere), and highly penetrative to enable in situ/in operando study of a real battery. Therefore, in recent years, development and application of advanced hard X-ray imaging technology has attracted tremendous attention.
Transmission X-ray microscopy (TXM) is a full-field high resolution x-ray imaging technique with a Fresnel zone plate serving as an objective lens. The newly developed TXM at X8C beamline, the National Synchrotron Light Source (NSLS) at Brookhaven National Lab (BNL) has offered new opportunities to directly image the interior microstructures of a variety of energy materials (batteries, fuel cell, functional nanomaterials, electrochemical deposition/corrosion, catalysts, etc.) in 2D and 3D at nanometer scale.[1-5] A particularly important capability of this new beamline is that it can provide chemical phase mapping information at nano-scale spatial resolution (sub-30 nm for 2D and sub-50 nm for 3D) rather than only averaged information by conventional X-ray absorption near edge structure (XANES) spectroscopy. The absorption mode (5-11 keV) covers most of transition-metal elements (e.g. Zn, Cu, Fe, Co, Ni, Mn, etc), which is particularly interesting for batteries, catalysts and other energy materials studies. The large field of view (40x40 µm) allows observing many particles in the sample at the same time, which will provide more accurate statistic information.
In the recent two years, our beamline have overcome the big challenges and demonstrated the new capabilities-in situ/in operando 2D/3D X-ray imaging studies in battery materials. The in operando 2D method allow us to track and identify the complex phase transformation and chemical change in a real battery. The in situ 3D method offers a direct way to look inside the electrochemical reaction, and provides 3D quantitative analysis of battery materials (surface area, volume, feature, curvature, etc.) to understand the materials structural degradation in a real battery, which guide the engineering of the advanced materials. This in situ/in operando imaging method is also applicable for other energy systems.
In this talk, we will present some research examples (batteries, fuel cells, etc.) to demonstrate the unique capabilities of our beamline for energy materials research field. The oncoming National Synchrotron Light Source II at BNL will provide TXM more capabilities to track the dynamic process in chemical/electrochemical reaction in a variety of energy system. More details about our beamline and the new light source (NSLS II at BNL) will be also discussed in this talk.

Figure 1