Full-Field Synchrotron Tomography of Nongraphitic Foam and Laminate Anodes for Lithium-Ion Batteries

Abstract

Nondestructive methods that allow researchers to gather high-resolution quantitative information on a material's physical properties from inside a working device are increasingly in demand from the scientific community. Synchrotron-based microcomputed X-ray tomography, which enables the fast, full-field interrogation of materials in functional, real-world environments, was used to observe the physical changes of next-generation lithium-ion battery anode materials and architectures. High capacity, nongraphitic anodes were chosen for study because they represent the future direction of the field and one of their recognized limitations is their large volume expansion and contraction upon cycling, which is responsible for their generally poor electrochemical performance. In this work, Cu6Sn5 coated on a three-dimensional copper foam was used to model a high power electrode while laminated silicon particles were used to model a high energy electrode. The electrodes were illuminated in situ and ex situ, respectively, at Sector 2-BM of the Advanced Photon Source. The changes in electrode porosity and surface area were measured and show large differences based on the electrode architecture. This work is one of the first reports of full-field synchrotron tomography on high-capacity battery materials under operating conditions.

Synchrotron X‐ray Tomographic Study of a Silicon Electrode Before and After Discharge and the Effect of Cavities on Particle Fracturing

“…X‐ray tomography operates by measuring variations in X‐ray attenuation coefficients in a rotating sample. Three‐dimensional reconstructions of samples with high spatial resolution can be obtained by using high‐flux synchrotron X‐ray facilities . Because all phases present in the electrode (Si particles, CBD and cavity) exhibit excellent contrast, due to different X‐ray attenuation coefficients, the morphological changes of particles, local CBD destruction and cavity formation could be studied in detail in 3D.…”

In situ/operando synchrotron-based X-ray techniques for lithium-ion battery research

“…Absorption contrast and phase contrast are the most commonly used mechanisms for full-field X-ray imaging methods. The power of real-space full-field imaging methods to visualize battery materials in real-time operation has been demonstrated by various recent works 20,[41][42][43][44][45][46][47][48][49] . Combined with spectroscopic measurements, full-field X-ray imaging becomes even more powerful for obtaining chemical information in addition to the morphological information.…”

Dynamics of the Morphological Degradation of Si‐Based Anodes for Li‐Ion Batteries Characterized by In Situ Synchrotron X‐Ray Tomography

“…X‐ray computed tomography (XRCT) is relevant for this purpose due to its ability to characterize complex structures in 3D. As listed in Table S1 (Supporting Information), this technique has been used for in situ and ex situ studies on various Si‐based electrodes, with a reconstructed volume ranging from ≈10 −3 to ≈10 mm 3 and a voxel size ranging from 0.06 to 9.3 µm (the spatial resolution corresponds to about two times the voxel size). Relevant information on the electrode degradation process have been obtained such as its delamination, the Si particle cracking and disconnections, the morphological evolution and connectivity of the pores and solid phases .…”