High-flux Synchrotron Radiation Research Articles

Understanding the Effects of Uniform Stack Pressure in Extreme Fast Charging Lithium-Ion Batteries Via Operando X-Ray Diffraction

Enabling fast charging in lithium-ion batteries (LIBs) is critical for electric vehicle development, the U.S. goal being to charge to 80% of full capacity in 15 minutes [1]. This is a challenge due to significant capacity fade occurring at charge rates of 6C (charge in 60/6 = 10 minutes) and above. Fast charge rates induce irreversible lithium (Li) plating that adversely impacts battery performance and safety. External stack pressure can improve electrical contact and minimize delamination; further, an understanding of the impact of pressure on capacity fade can provide insight into the degradation mechanisms [2,3]. In this work, we investigate the extreme fast charging (XFC) regime, focusing on cell degradation and parasitic Li plating using single-layer pouch cells with graphite anodes, LiNi0.5Mn0.3Co0.2O2 (NMC532) cathodes, and 1.2 M LiPF6 in 3:7 weight % ethylene carbonate and diethyl carbonate (Gen2 electrolyte). To study the effect of pressure, electrode thickness and material capacity were varied. Cells were cycled under set uniform stack pressure configurations at 6C up to 140 times and tested between 10 – 150 psi. We have characterized fast charging cells under uniform pressure with spatially resolved operando X-ray diffraction (XRD) from high energy, high flux synchrotron radiation to study Li plating, parasitic reactions, and Li intercalation into graphite. Through spatially resolved operando XRD, we have mapped the intensity of LixC6 and Li metal peaks across the electrode to correlate peak intensity as a function of pressure and electrode thickness. This was complemented with ex situ X-ray photoelectron spectroscopy to study the composition of parasitic reaction products, corrosion and to correlate heterogeneity and local Li plating. Our results show an improvement in battery performance with increased uniform pressure. A reduction in Li plating was observed at elevated uniform pressures and Li plating appears more prevalent on the thicker electrodes. We believe that at increased pressure the reduced capacity fade arises from improved wettability, where the electrolyte acts as a lubricant increasing active sights, and a reduction in polarization across the thickness of the electrode leading to more homogenous reaction conditions. We emphasize the importance of electrode stack pressure in XFC batteries by quantifying the degradation mechanisms that cause capacity fade to enable better battery engineering.References USABC Goals – Lithium Electrode Based Cell and Manufacturing for Automotive Traction Applications, USABC (United States Advanced Battery Consortium), http://www.uscar.org/guest/article_view.php?articles_id=85C. Cao et al. J. Electrochem. Soc. 129, 040540 (2022).J. Cannarella and C. B. Arnold, J. Power Source, 245, 745-751 (2014).

Realizing the AF4-UV-SAXS on-line coupling on protein and antibodies using high flux synchrotron radiation at the CoSAXS beamline, MAX IV.

In this paper, we demonstrate the coupling of synchrotron small angle X-ray scattering (SAXS) to asymmetrical flow-field flow fractionation (AF4) for protein characterization. To the best of our knowledge, this is the first time AF4 is successfully coupled to a synchrotron for on-line measurements on proteins. This coupling has potentially high impact, as it opens the possibility to characterize individual constituents of sensitive and/or complex samples, not suited for separation using other techniques, and for low electron density samples where high X-ray flux is required, e.g., biomolecules and biologics. AF4 fractionates complex samples in native or close to native environment, with low shear forces and system surface area. Many orders of magnitude in size can be fractionated in one measurement, without having to reconfigure the experimental setup. We report AF4 fractionations with correlated UV and statistically adequate SAXS data of bovine serum albumin and a monoclonal antibody and evaluate SAXS data recorded for the two protein systems.

A reactor for time-resolved X-ray studies of nucleation and growth during solvothermal synthesis.

Understanding the nucleation and growth mechanisms of nanocrystals under hydro- and solvothermal conditions is key to tailoring functional nanomaterials. High-energy and high-flux synchrotron radiation is ideal for characterization by powder X-ray diffraction and X-ray total scattering in real time. Different versions of batch-type cell reactors have been employed in this work, exploiting the robustness of polyimide-coated fused quartz tubes with an inner diameter of 0.7 mm, as they can withstand pressures up to 250 bar and temperatures up to 723 K for several hours. Reported here are recent developments of the in situ setups available for general users on the P21.1 beamline at PETRA III and the DanMAX beamline at MAX IV to study nucleation and growth phenomena in solvothermal synthesis. It is shown that data suitable for both reciprocal-space Rietveld refinement and direct-space pair distribution function refinement can be obtained on a timescale of 4 ms.

A new practical design of a merged APPLE-Knot undulator for High Energy Photon Source

To obtain high flux and polarization adjustable synchrotron radiation with low on-axis power density, a type of pure permanent magnetic undulator called merged APPLE-Knot has been proposed. The original configuration of the merged APPLE-Knot undulator neglects the existence of knot vacancies and sets all magnets to the same size, the polarization of fundamental photons decreases dramatically as the gap increases in vertical polarization mode. To deal with this problem, a new configuration that increases the size of the merged magnets and shifts two Knot arrays respectively before merging the magnets has been proposed. However, there is a notable net kick for electrons due to the asymmetry of magnetization orientation distribution of two magnet arrays in circular polarization mode. It cannot be corrected by end magnets only, extra current strips are needed. Here, the configuration of merged APPLE-Knot with symmetrical magnetization orientation distribution proved to be a good choice as well to obtain a good performance of synchrotron radiation without extra current strips.

A practical design and field errors analysis of a merged APPLE–Knot undulator for High Energy Photon Source

Users of HEPS require polarization adjustable and high-flux synchrotron radiation with energy of 100–2000 eV. To achieve 100 eV photon energy at HEPS, a 6 GeV storage ring, the problem of on-axis heat load becomes a significant challenge for users. A new type of four-row merged APPLE–Knot undulator recently proposed seems to be the most effective solution to reduce on-axis power density. However, as an undulator with such complex magnetization orientation distribution of magnetic blocks, its field integrals correction and the effect of field errors on the radiation performance are different from that of conventional EPU. Whether it can realize its field integrals correction and perform as well as in theory with field errors has become a concern. Here, a set of field integrals correction schemes is reported and field errors analysis has been done. A general method for evaluating the effect of magnetization orientation deviation of the magnetic block on radiation performance is proposed. It can be used for any insertion device containing permanent magnetic magnets if necessary.

X-ray phase contrast and absorption imaging for the quantification of transient cavitation in high-speed nozzle flows

High-flux synchrotron radiation has been employed in a time-resolved manner to characterize the distinct topology features and dynamics of different cavitation regimes arising in a throttle orifice with an abrupt flow-entry contraction. Radiographs obtained though both x-ray phase-contrast and absorption imaging have been captured at 67 890 frames per second. The flow lies in the turbulent regime (Re = 35 500), while moderate (CN = 2.0) to well-established (CN = 6.0) cavitation conditions were examined encompassing the cloud and vortical cavitation regimes with pertinent transient features, such as cloud-cavity shedding. X-ray phase-contrast imaging, exploiting the shift in the x-ray wave phase during interactions with matter, offers sharp-refractive index gradients in the interface region. Hence, it is suitable for capturing fine morphological fluctuations of transient cavitation structures. Nevertheless, the technique cannot provide information on the quantity of vapor within the orifice. Such data have been obtained utilizing absorption imaging, where beam attenuation is not associated with scattering and refraction events, and hence can be explicitly correlated with the projected vapor thickness in line-of-sight measurements. A combination of the two methods is proposed as it has been found that it is capable of quantifying the vapor content arising in the complex nozzle flow while also faithfully illustrating the dynamics of the highly transient cavitation features.

A novel experimental setup for in situ optical and X-ray imaging of laser sintering of polymer particles.

We present a unique laser sintering setup that allows real time studies of the structural evolution during laser sintering of polymer particles. The device incorporates the main features of classical selective laser sintering machines for 3D printing of polymers and at the same time allows in situ visualization of the sintering dynamics with optical microscopy as well as X-ray scattering. A main feature of the setup is the fact that it provides local access to one particle-particle bridge during sintering. In addition, due to the small scale of the device and the specific laser arrangement process, parameters such as the temperature, laser energy, laser pulse duration, and spot size can be precisely controlled. The sample chamber provides heating up to 360 °C, which allows for sintering of commodity as well as high performance polymers. The latter parameters are controlled by the use of a visible light laser combined with an acousto-optic modulator for pulsing, which allows small and precise spot sizes and pulse times and pulse energies as low as 500 μs and 17 μJ. The macrostructural evolution of the particle bridge during sintering is followed via optical imaging at high speed and resolution. Placing the setup in high flux synchrotron radiation with a fast detector simultaneously allows in situ time-resolved X-ray characterizations. To demonstrate the capabilities of the device, we studied the laser sintering of two spherical PA12 particles. The setup provides crucial real-time information concerning the sintering dynamics as well as crystallization kinetics, which was not accessible up to now.

High-flux x-ray photon emission by a superluminal hybrid electromagnetic mode of intense laser in a plasma waveguide

The feasibility of several novel ultrafast x-ray sources has been demonstrated through the interaction between laser and a micro-structured target. However, the resulting photon flux is still deficient for some applications. Here, we proposed a new method to yield high-flux synchrotron radiation by adopting compact hollow plasma waveguide. We verified the method theoretically and numerically. Linearly polarized laser pulses propagating in the waveguide are mainly converted into the electromagnetic mode HE11 with a superluminal phase speed of 1.02c when the pulse is coupled with the waveguide. The mode fields lead to a strong oscillating force and short oscillation period for energetic electrons, which are accelerated via the longitudinal acceleration mechanism. Then, the short x-ray beam is generated with high yield of 1011–1012. The corresponding photon flux reaches 3.5 × 1021 photons s−1 · 0.1% bandwidth. The high-flux source can be even used for single shot ultrafast imaging or the ultrafast x-ray diffraction and absorption studies.

Detection of high flux synchrotron radiation based on diamond detector for HEPS

High Energy Photon Source (HEPS) with a beam energy of 6 GeV and emittance less than 1.0 nm rad will be constructed in China, which can provide high-brightness hard X-ray in the order of 1022 (phs/s/mm2/mr2/0.1%B.W.). The broadband and high-brightness monochromatic beam flux and white beam flux need new detector other than the ion chambers for measurement in case of saturation under high-flux conditions. The Diamond X-ray detector for the beam position monitoring and high brightness X-ray detection is developing for High Energy Photon Source in China. The diamond detector has advantages over other detector materials: a low atomic number resulting in a low absorption cross-section when used as beam position monitor and a high radiation and wide linear range when used as beam intensity measuring. In this paper, the polycrystalline chemical-vapour-deposition diamond detectors with an aluminium contact have been tested at 1W2B beamline at Beijing Synchrotron Radiation Facility (BSRF). A transmission-mode diamond X-ray detector is designed to simultaneously measure the X-ray flux, beam position in real time.

Illustrating the effect of viscoelastic additives on cavitation and turbulence with X-ray imaging

The effect of viscoelastic additives on the topology and dynamics of the two-phase flow arising within an axisymmetric orifice with a flow path constriction along its main axis has been investigated employing high-flux synchrotron radiation. X-ray Phase Contrast Imaging (XPCI) has been conducted to visualise the cavitating flow of different types of diesel fuel within the orifice. An additised blend containing Quaternary Ammonium Salt (QAS) additives with a concentration of 500 ppm has been comparatively examined against a pure (base) diesel compound. A high-flux, 12 keV X-ray beam has been utilised to obtain time resolved radiographs depicting the vapour extent within the orifice from two views (side and top) with reference to its main axis. Different test cases have been examined for both fuel types and for a range of flow conditions characterised by Reynolds number of 35500 and cavitation numbers (CN) lying in the range 3.0–7.7. It has been established that the behaviour of viscoelastic micelles in the regions of shear flow is not consistent depending on the cavitation regimes encountered. Namely, viscoelastic effects enhance vortical (string) cavitation, whereas hinder cloud cavitation. Furthermore, the use of additised fuel has been demonstrated to suppress the level of turbulence within the orifice.

Thermotropic phase behavior of milk sphingomyelin and role of cholesterol in the formation of the liquid ordered phase examined using SR-XRD and DSC

Sphingomyelin (SM) and cholesterol are major lipid components of biological membranes involved in the formation of ordered domains. In this study, we investigated the biophysical properties of milk-SM bilayers and determined the effect of cholesterol. The thermotropic phase behaviours of milk-SM and milk-SM/cholesterol mixtures were characterized using differential scanning calorimetry (DSC) and high flux synchrotron radiation X-ray diffraction (SR-XRD). The melting phase transition temperature determined for fully hydrated milk-SM bilayers was Tm = 34.3 ± 0.1 °C. The thermotropic phase behavior of milk-SM is complex, reflecting the mixture of different molecular species. Structural reorganisations successively occurring on heating of fully hydrated milk-SM bilayers were interpreted as follows: i) melting of C16:0-SM, ii) conversion of long and saturated SM species from fully interdigitated (Lβ1) to mixed interdigitated (Lβ2) lamellar structures evidencing gel phase polymorphism and then iii) transition to the fluid liquid-crystal Lα phase. We demonstrated that cholesterol modulates the physical properties of milk-SM bilayers and that building up of the lamellar liquid-ordered Lo phase is completed for 33 mol% of cholesterol. The ordering effect of cholesterol on milk-SM bilayers and the temperature-independent behavior of the Lo phase formed by milk-SM/cholesterol complexes were characterized. The findings of this work will contribute in a better understanding of the biological functions exerted by the milk-SM as a function of its phase state and interactions with cholesterol (e.g. hypocholesterolemic effect).

High-speed visualization of vortical cavitation using synchrotron radiation

High-speed X-ray phase-contrast imaging of the cavitating flow developing within an axisymmetric throttle orifice has been conducted using high-flux synchrotron radiation. A white X-ray beam with energy of 6 keV was utilized to visualize the highly turbulent flow at 67 890 frames per second with an exposure time of 347 ns. The working medium employed was commercial diesel fuel at flow conditions characterized by Reynolds and cavitation numbers in the range of 18 000–35 500 and 1.6–7.7, respectively. Appropriate post-processing of the obtained side-view radiographs enabled the detailed illustration of the interface topology of the arising vortical cavity. In addition, the visualization temporal and spatial resolution allowed the correlation of the prevailing flow conditions to the periodicity of cavitation onset and collapse, to the magnitude of the underlying vortical motion, as well as to the local turbulence intensity.

Online monitoring the detector calibration process at a synchrotron X-ray source

This paper describes an online noble gas monitor used for the detector calibration process with a cryogenic radiometer. The process is implemented under a high-flux synchrotron radiation X-ray source in the energy range from 2100 to 6000 eV at the Beijing Synchrotron Radiation Facility (BSRF). This online monitoring system aims to lower the uncertainty of the calibration results caused by electron beam decay in the storage ring during the detector calibration process. Because the calibration process is performed under the high vacuum condition, an ionization chamber with adjustable Kr gas pressure is chosen as the monitoring device. To decrease the electronic noise, a method for obtaining the signal by collecting the counts within a specified time has been applied. Under the properly controlled conditions, the uncertainty of the calibration results introduced by the online monitoring system is estimated to be better than 0.15%, which can meet the demands of various high-precision calibration processes.

Use of Multiple Cryoprotectants to Improve Diffraction Quality from Protein Crystals

Current X-ray sources—such as high-flux synchrotron radiation and XFEL—enable us to determine the tertiary structures of proteins at medium or low resolution even from crystals with poor quality. However, high-resolution crystal structures are still required to obtain detailed information about protein structures in the pharmaceutical and biochemical sciences. To improve the crystal quality, several types of post-crystallization treatments, including soaking experiments, have been utilized. However, such treatments do not always improve the crystal quality, and a new method of crystal-quality enhancement is eagerly awaited. Here, we propose a novel strategy for the post-crystallization treatment, the multistep soaking method, in which a crystal is sequentially soaked in 2–3 different cryoprotectant solutions. The sequential use of different cryoprotectants significantly expands the number of options for subsequent post-crystallization treatment. Using the new method, we successfully improved the crystal q...

The Crystalline Sponge Method: Synthetic and Crystallographic Guidelines

Synthetic and crystallographic guidelines for the crystalline sponge method based upon the analysis of rapidly-synthesized crystal sponges using high-flux synchrotron radiation are presented [1]. The synthetic procedure for the zinc-based metal-organic framework (MOF) used in preliminary crystal sponge reports [2, 3] has been modified to afford suitable sponges in 3 days instead of 2 weeks. These sponges were tested on some small molecules, with two being difficult cases for in-house diffraction analysis in regards to data quality and determination of space group. These issues were readily resolved by the use of high-flux synchrotron radiation with <1 hour data collection times. None of the structures required the use of electron density removal programs to treat solvent accessible voids. The crystalline sponge systems analyzed in this study are the highest-quality structures of this class presented to date that meets chemical crystallographic standards. As a result of these studies, a set of guidelines for the crystallographic process were developed, and the single crystal to single crystal transformation process for these systems was also analyzed. The presented guidelines will be helpful for those interested in using the crystalline sponge method to fully elucidate the structures of non-crystallizable compounds at in-house diffraction or synchrotron facilities, and will aid in obtaining data that meet the standards of chemical crystallography.

Adsorption and stability of malonic acid on rutile TiO2 (110), studied by near edge X-ray absorption fine structure and photoelectron spectroscopy

The adsorption of malonic acid on rutile TiO2 (110) has been studied using photoelectron spectroscopy and C K-edge, near edge X-ray fine structure spectroscopy (NEXAFS). Analysis of the O 1s and Ti 2p spectra suggest that the molecule adsorbs dissociatively in a doubly-bidentate adsorption geometry as malonate. The data are unable to distinguish between a chelating bonding mode with the backbone of the molecule lying along the [001] azimuth or a bridging geometry along the direction. Work carried out on a wiggler beamline suggests that the molecule is unstable under irradiation by high-flux synchrotron radiation from this type of insertion device.

In situ observations of the mesophase formation of isotactic polypropylene—A fast time-resolved X-ray diffraction study

In situ observation of the formation process of mesophase of isotactic polypropylene (iPP) is reported in structural point of view. Combining a rapid temperature jump and a high-flux synchrotron radiation X-ray scattering techniques, very rapid transformation from the molten amorphous state to the mesophase has been observed. The transformation proceeded very quickly in a narrow temperature range accompanied by instantaneous fluctuations in micrometer scale, suggesting the mesophase formation proceeds similarly to spinodal decomposition.

Orientation dynamics in multiwalled carbon nanotube dispersions under shear flow

We report studies of the orientation state of multiwalled carbon nanotubes (MWNTs) dispersions in steady and transient shear flows. Uncured epoxy was used as a viscous Newtonian suspending medium and samples were prepared from "aligned" MWNTs using methods previously reported [S. S. Rahatekar et al., J. Rheol. 50, 599 (2006)]. Orientation measurements were performed in both the flow-gradient (1-2) and flow-vorticity (1-3) plane of simple shear flow using in situ x-ray scattering techniques. Steady state measurements in the 1-2 plane indicate that the MWNT orientation is shear rate dependent, with the MWNTs orienting closer to the flow direction at higher shear rates. During steady shear, anisotropy was measured to be higher in the 1-2 plane than in the 1-3 plane, demonstrating that the nanotube orientation state is not unaxially symmetric in shear. It is hypothesized that the steady state MWNT orientation is governed primarily by a rate-dependent state of nanotube aggregation/disaggregation, which was separately characterized by optical microscopy of the same samples under shear. High flux synchrotron radiation allowed for time-resolved structural studies in transient flows. A partial relaxation of flow-induced anisotropy was observed following flow cessation, despite the very small rotational diffusivity estimated for these nanotubes. Long transients are observed in step-down experiments, as the orientation state changes in response to the slow tube aggregation process.

An apparatus for in situ x-ray scattering measurements during polymer injection molding

We report a novel instrument for synchrotron-based in situ x-ray scattering measurements during injection molding processing. It allows direct, real-time monitoring of molecular-scale structural evolution in polymer materials undergoing a complex processing operation. The instrument is based on a laboratory-scale injection molding machine, and employs customized mold tools designed to allow x-ray access during mold filling and subsequent solidification, while providing sufficient robustness to withstand high injection pressures. The use of high energy, high flux synchrotron radiation, and a fast detector allows sufficiently rapid data acquisition to resolve time-dependent orientation dynamics in this transient process. Simultaneous monitoring of temperature and pressure signals allows transient scattering data to be referenced to various stages of the injection molding cycle. Representative data on a commercial liquid crystalline polymer, Vectra(R) B950, are presented to demonstrate the features of this apparatus; however, it may find application in a wide range of polymeric materials such as nanocomposites, semicrystalline polymers and fiber-reinforced thermoplastics.

Light flux density threshold at which protein denaturation is induced by synchrotron radiation circular dichroism beamlines

New high-flux synchrotron radiation circular dichroism (SRCD) beamlines are providing important information for structural biology, but can potentially cause denaturation of the protein samples under investigation. This effect has been studied at the new CD1 dedicated SRCD beamline at ISA in Denmark, where radiation-induced thermal damage effects were observed, depending not only on the radiation flux but also on the focal spot size of the light. Comparisons with similar studies at other SRCD facilities worldwide has lead to the estimation of a flux density threshold under which SRCD beamlines should be operated when samples are to be exposed to low-wavelength vacuum ultraviolet radiation for extended periods of time.