Redox oscillations in 18650-type lithium-ion cell revealed by in operando Compton scattering imaging

Compton scattering imaging using high-energy synchrotron x rays allows the visualization of the spatiotemporal lithiation state in lithium-ion batteries probed in operando. Here, we apply this imaging technique to the commercial 18650-type cylindrical lithium-ion battery. Our analysis of the line shapes of the Compton scattering spectra taken from different electrode layers reveals the emergence of inhomogeneous lithiation patterns during the charge-discharge cycles. Moreover, these patterns exhibit oscillations in time where the dominant period corresponds to the timescale of the charging curve.Peer reviewe

Improvement in Dacryoendoscopic Visibility after Image Processing Using Comb-Removal and Image-Sharpening Algorithms

Recently, a minimally invasive treatment for lacrimal passage diseases was developed using dacryoendoscopy. Good visibility of the lacrimal passage is important for examination and treatment. This study aimed to investigate whether image processing can improve the dacryoendoscopic visibility using comb-removal and image-sharpening algorithms. We processed 20 dacryoendoscopic images (original images) using comb-removal and image-sharpening algorithms. Overall, 40 images (20 original and 20 post-processing) were randomly presented to the evaluators, who scored each image on a 10-point scale. The scores of the original and post-processing images were compared statistically. Additionally, in vitro experiments were performed using a test chart to examine whether image processing could improve the dacryoendoscopic visibility in a turbid fluid. The visual score (estimate ± standard error) of the images significantly improved from 3.52 ± 0.26 (original images) to 5.77 ± 0.28 (post-processing images; p < 0.001, linear mixed-effects model). The in vitro experiments revealed that the contrast and resolution of images in the turbid fluid improved after image processing. Image processing with our comb-removal and image-sharpening algorithms improved dacryoendoscopic visibility. The techniques used in this study are applicable for real-time processing and can be easily introduced in clinical practice

Non-Destructive Analysis of a High-Power Capacitor Using High-Energy X-ray Compton Scattering

Changes in the internal state of a high-power capacitor during progressive charge–discharge cycling were measured non-destructively using high-energy synchrotron X-ray Compton scattering. The stacked structure of a laminated capacitor was clearly indicated by a Compton scattered X-ray intensity analysis and a line shape (S-parameter) analysis of a Compton scattered X-ray energy spectrum. Moreover, apparent differences in the progress of charge and discharge cycles were observed in the correlation between Compton scattered X-ray intensities and S-parameters obtained from the center and edge positions within the in-plane of the electrode. This difference in the correlation was obtained from the shifting of the stacked structure at the edge position, induced by the drift of the electrolyte material within the capacitor cells

Development of non-destructive testing (NDT) technique for HIPed interface by Compton scattering X-ray spectroscopy

High energy X-rays (115.56 keV) were used to measure the HIPed interface of F82H steel. The X-ray energy spectra of the samples were analyzed focusing on W and Ta fluorescence X-rays, Compton scattering and elastic scattering X-rays. The results suggest the presence of SiOx and TaOx at the HIP interface and the accumulation of W near the HIP interface. These results indicate that high-energy X-ray spectrum analysis can be a non-destructive testing technique (NDT) to evaluate precipitates at the HIP interface of F82H steel

Magnetic Compton Scattering Study of Li-Rich Battery Materials

The redox process in a lithium-ion battery occurs when a conduction electron from the lithium anode is transferred to the redox orbital of the cathode. Understanding the nature of orbitals involved in anionic as well as cationic redox reactions is important for improving the capacity and energy density of Li-ion batteries. In this connection, we have obtained magnetic Compton profiles (MCPs) from the Li-rich cation-disordered rock-salt compound LixTi0.4Mn0.4O2 (LTMO). The MCPs, which involved the scattering of circularly polarized hard X-rays, are given by the momentum density of all the unpaired spins in the material. The net magnetic moment in the ground state can be extracted from the area under the MCP, along with a SQUID measurement. Our analysis gives insight into the role of Mn 3d magnetic electrons and O 2p holes in the magnetic redox properties of LTMO