From atoms to electrodes: Mesoscale effects in electrochemical conversion

Batteries are complex multicomponent devices wherein mesoscale phenomena–the nanoscale structure and chemistry of different components, and interactions thereof–drive functionality and performance. For example, electron/ion transport within the composite electrodes relies on bi-continuous nanostructuring to form electrically and ionicly conductive paths. Electrochemical conversion of different salts of a given metal yields a common and ostensibly identical product: the zero valent metal. For example, maximal lithiation of iron-based electrodes produces metallic iron nanoparticles for oxide, fluoride, and oxyfluoride electrodes alike. Accordingly, these provide an opportunity to explore the coupling of nanostructure development and anion chemistry, and correlate these with electrochemical performance. We combine synchrotron-based small angle X-ray scattering (SAXS) and pair distribution function (PDF) measurements to probe metallic iron formed by electrochemical conversion of different iron compounds across multiple length-scales and decouple the influence of anion chemistry and reaction temperature on the atomic structure and nanoscale morphology.

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A multi-length-scale USAXS/SAXS facility: 10–50 keV small-angle X-ray scattering instrument

Journal of Applied Crystallography ◽

10.1107/s0021889813021900 ◽

2013 ◽

Vol 46 (5) ◽

pp. 1508-1512 ◽

Cited By ~ 11

Author(s):

Byron Freelon ◽

Kamlesh Suthar ◽

Jan Ilavsky

Keyword(s):

Small Angle ◽

Soft Matter ◽

High Energy ◽

X Rays ◽

X Ray ◽

X Ray Scattering ◽

Wide Range ◽

And Performance ◽

New Facility ◽

Ray Scattering

Coupling small-angle X-ray scattering (SAXS) and ultra-small-angle X-ray scattering (USAXS) provides a powerful system of techniques for determining the structural organization of nanostructured materials that exhibit a wide range of characteristic length scales. A new facility that combines high-energy (HE) SAXS and USAXS has been developed at the Advanced Photon Source (APS). The application of X-rays across a range of energies, from 10 to 50 keV, offers opportunities to probe structural behavior at the nano- and microscale. An X-ray setup that can characterize both soft matter or hard matter and high-Zsamples in the solid or solution forms is described. Recent upgrades to the Sector 15ID beamline allow an extension of the X-ray energy range and improved beam intensity. The function and performance of the dedicated USAXS/HE-SAXS ChemMatCARS-APS facility is described.

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Temperature-gradient analyzers for non-resonant inelastic X-ray scattering

Journal of Synchrotron Radiation ◽

10.1107/s160057752100179x ◽

2021 ◽

Vol 28 (3) ◽

Author(s):

Daisuke Ishikawa ◽

Alfred Q. R. Baron

Keyword(s):

Temperature Gradient ◽

Solid Angle ◽

Dispersion Compensation ◽

Full Width ◽

Half Maximum ◽

Sensitive Detector ◽

X Ray ◽

X Ray Scattering ◽

Position Sensitive ◽

And Performance

The detailed fabrication and performance of the temperature-gradient analyzers that were simulated by Ishikawa & Baron [(2010). J. Synchrotron Rad. 17, 12–24] are described and extended to include both quadratic and 2D gradients. The application of a temperature gradient compensates for geometric contributions to the energy resolution while allowing collection of a large solid angle, ∼50 mrad × 50 mrad, of scattered radiation. In particular, when operating relatively close to backscattering, π/2 − θB = 1.58 mrad, the application of a gradient of 1.32 K per 80 mm improves the measured total resolution from 60 to 25 meV at the full width at half-maximum, while when operating further from backscattering, π/2 − θB = 6.56 mrad, improvement from 330 to 32 meV is observed using a combination of a gradient of 6.2 K per 80 mm and dispersion compensation with a position-sensitive detector. In both cases, the operating energy was 15.8 keV and the incident bandwidth was 22 meV. Notably, the use of a temperature gradient allows a relatively large clearance at the sample, permitting installation of more complicated sample environments.

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Classification of grazing-incidence small-angle X-ray scattering patterns by convolutional neural network

Journal of Synchrotron Radiation ◽

10.1107/s1600577520005767 ◽

2020 ◽

Vol 27 (4) ◽

pp. 1069-1073

Author(s):

Hiroyuki Ikemoto ◽

Kazushi Yamamoto ◽

Hideaki Touyama ◽

Daisuke Yamashita ◽

Masataka Nakamura ◽

...

Keyword(s):

Neural Network ◽

Convolutional Neural Network ◽

Small Angle ◽

Pair Correlation ◽

Grazing Incidence ◽

X Ray ◽

X Ray Scattering ◽

Nanoscale Structure ◽

Ray Scattering

Grazing-incidence small-angle X-ray scattering (GISAXS) patterns have multiple superimposed contributions from the shape of the nanoscale structure, the coupling between the particles, the partial pair correlation, and the layer geometry. Therefore, it is not easy to identify the model manually from the huge amounts of combinations. The convolutional neural network (CNN), which is one of the artificial neural networks, can find regularities to classify patterns from large amounts of combinations. CNN was applied to classify GISAXS patterns, focusing on the shape of the nanoparticles. The network found regularities from the GISAXS patterns and showed a success rate of about 90% for the classification. This method can efficiently classify a large amount of experimental GISAXS patterns according to a set of model shapes and their combinations.

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Highly versatile laboratory X-ray scattering instrument enabling (nano-)material structure analysis on multiple length scales by covering a scattering vector range of almost five decades

Review of Scientific Instruments ◽

10.1063/1.5130061 ◽

2019 ◽

Vol 90 (12) ◽

pp. 123103 ◽

Cited By ~ 1

Author(s):

Joerg Bolze ◽

Milen Gateshki

Keyword(s):

Structure Analysis ◽

Material Structure ◽

Length Scales ◽

X Ray ◽

X Ray Scattering ◽

Multiple Length Scales ◽

Nano Material ◽

Ray Scattering

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The SPECIES beamline at the MAX IV Laboratory: a facility for soft X-ray RIXS and APXPS

Journal of Synchrotron Radiation ◽

10.1107/s1600577516019056 ◽

2017 ◽

Vol 24 (1) ◽

pp. 344-353 ◽

Cited By ~ 18

Author(s):

Samuli Urpelainen ◽

Conny Såthe ◽

Walan Grizolli ◽

Marcus Agåker ◽

Ashley R. Head ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Ambient Pressure ◽

Unique Property ◽

Unique Combination ◽

X Ray ◽

Fast Switching ◽

X Ray Scattering ◽

And Performance ◽

Ring Species ◽

X Ray Absorption

SPECIES is an undulator-based soft X-ray beamline that replaced the old I511 beamline at the MAX II storage ring. SPECIES is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (APXPS), near-edge X-ray absorption fine-structure (NEXAFS), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) experiments. The beamline has two branches that use a common elliptically polarizing undulator and monochromator. The beam is switched between the two branches by changing the focusing optics after the monochromator. Both branches have separate exit slits, refocusing optics and dedicated permanent endstations. This allows very fast switching between two types of experiments and offers a unique combination of the surface-sensitive XPS and bulk-sensitive RIXS techniques both in UHV and at elevated ambient-pressure conditions on a single beamline. Another unique property of the beamline is that it reaches energies down to approximately 27 eV, which is not obtainable on other current APXPS beamlines. This allows, for instance, valence band studies under ambient-pressure conditions. In this article the main properties and performance of the beamline are presented, together with selected showcase experiments performed on the new setup.

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Ion-Specific Clustering of Metal-Amphiphile Complexes in Rare Earth Separations

10.26434/chemrxiv.11938182.v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Srikanth Nayak ◽

Kaitlin Lovering ◽

Ahmet Uysal

Keyword(s):

Aqueous Phase ◽

Organic Phase ◽

Immiscible Liquids ◽

X Ray ◽

Clustering Model ◽

X Ray Scattering ◽

Heavy Lanthanides ◽

Complex Fluid ◽

Nanoscale Structure ◽

Ray Scattering

Aggregation and clustering of metal-amphiphile complexes formed during solvent extraction of lanthanides have been studied with small angle X-ray scattering. The nanoscale structure of the complex fluid strongly depends on the counter-ion (NO3- or SCN-) and the lanthanide being extracted. As a result, it is possible to selectively transport light or heavy lanthanides from the aqueous phase into the organic phase by simply choosing NO3- or SCN- as the background anion, respectively. While the organic phase containing TOMA-NO3 always shows clustering, indicating the presence of stronger attractive interactions between metal-amphiphile aggregates, TOMA-SCN shows clustering as a function of the metal loading. These qualitative differences suggest that the extraction efficiency is driven by the aqueous phase conditions in NO3- solutions, while it is driven by the organic phase structuring in SCN- solutions. A clustering model, that accounts for the hard sphere repulsions and short-range attractions between the aggregates, has been developed to model the X-ray scattering results. The new model successfully describes the nanoscale structure and helps understanding the mechanisms responsible for amphiphile assisted ion transport and complexation between immiscible liquids.

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Optical design and performance of the biological small-angle X-ray scattering beamline at the Taiwan Photon Source

Journal of Synchrotron Radiation ◽

10.1107/s1600577521009565 ◽

2021 ◽

Vol 28 (6) ◽

Author(s):

D.-G. Liu ◽

C.-H. Chang ◽

L.-C. Chiang ◽

M.-H. Lee ◽

C.-F. Chang ◽

...

Keyword(s):

Small Angle ◽

Optical Design ◽

Scattering Data ◽

High Energy Resolution ◽

High Flux ◽

X Ray ◽

X Ray Scattering ◽

And Performance ◽

Photon Source ◽

Ray Scattering

The optical design and performance of the recently opened 13A biological small-angle X-ray scattering (SAXS) beamline at the 3.0 GeV Taiwan Photon Source of the National Synchrotron Radiation Research Center are reported. The beamline is designed for studies of biological structures and kinetics in a wide range of length and time scales, from angstrom to micrometre and from microsecond to minutes. A 4 m IU24 undulator of the beamline provides high-flux X-rays in the energy range 4.0–23.0 keV. MoB4C double-multilayer and Si(111) double-crystal monochromators (DMM/DCM) are combined on the same rotating platform for a smooth rotation transition from a high-flux beam of ∼4 × 1014 photons s−1 to a high-energy-resolution beam of ΔE/E ≃ 1.5 × 10−4; both modes share a constant beam exit. With a set of Kirkpatrick–Baez (KB) mirrors, the X-ray beam is focused to the farthest SAXS detector position, 52 m from the source. A downstream four-bounce crystal collimator, comprising two sets of Si(311) double crystals arranged in a dispersive configuration, optionally collimate the DCM (vertically diffracted) beam in the horizontal direction for ultra-SAXS with a minimum scattering vector q down to 0.0004 Å−1, which allows resolving ordered d-spacing up to 1 µm. A microbeam, of 10–50 µm beam size, is tailored by a combined set of high-heat-load slits followed by micrometre-precision slits situated at the front-end 15.5 m position. The second set of KB mirrors then focus the beam to the 40 m sample position, with a demagnification ratio of ∼1.5. A detecting system comprising two in-vacuum X-ray pixel detectors is installed to perform synchronized small- and wide-angle X-ray scattering data collections. The observed beamline performance proves the feasibility of having compound features of high flux, microbeam and ultra-SAXS in one beamline.

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Ion-Specific Clustering of Metal-Amphiphile Complexes in Rare Earth Separations

10.26434/chemrxiv.11938182 ◽

2020 ◽

Author(s):

Srikanth Nayak ◽

Kaitlin Lovering ◽

Ahmet Uysal

Keyword(s):

Rare Earth ◽

Selective Adsorption ◽

Lanthanide Ions ◽

X Ray ◽

Clustering Model ◽

X Ray Scattering ◽

Hierarchical Structuring ◽

Complex Fluid ◽

Nanoscale Structure ◽

Ray Scattering

The nanoscale structure of a complex fluid can play a major role in the selective adsorption of ions at the nanometric interfaces, which are crucial in industrial and technological applications. Here we study the effect of anions and lanthanide ions on the nanoscale structure of a complex fluid formed by metal-amphiphile complexes, using small angle X-ray scattering. The nano- and mesoscale structures we observe can be directly connected to preferential transfer of light (La, Nd) or heavy (Er, Lu) lanthanides into the complex fluid from an aqueous solution. While the toluene-based complex fluids containing trioctylmethylammonium-nitrate (TOMA-nitrate) always show the same mesoscale hierarchical structure regardless of lanthanide loading and prefer light lanthanides, those containing TOMA-thiocyanate show an evolution of mesoscale structure as a function of the lanthanide loading and prefer heavy lanthanides. The hierarchical structuring indicates the presence of attractive interactions between ion-amphiphile aggregates, causing them to form clusters. A clustering model, that accounts for the hard sphere repulsions and short-range attractions between the aggregates, has been adapted to model the X-ray scattering results. The new model successfully describes the nanoscale structure and helps in understanding the mechanisms responsible for amphiphile assisted ion transport between immiscible liquids. Accordingly, our results imply different mechanisms of lanthanide transport depending on the anion present in the complex fluid and correspond with anion-dependent trends in rare-earth separations.

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New Modular Calamitic Ligands for Self-Assembly of Thermostable Quantum Dot Microcapsules via Nematic Templating

10.26434/chemrxiv.7092821.v1 ◽

2018 ◽

Author(s):

Amir Keshavarz ◽

Sheida Riahinasab ◽

Linda Hirst ◽

Ben Stokes

Keyword(s):

Quantum Dot ◽

Self Assembly ◽

Organic Ligands ◽

Interparticle Spacing ◽

Design Synthesis ◽

X Ray ◽

New Class ◽

X Ray Scattering ◽

Synthesis Properties ◽

And Performance

The design, synthesis, properties, and performance of a new class of promesogenic calamitic side-tethering organic ligands used to direct quantum dot nanoparticle self-assembly via nematic templating are described. This work was motivated by inadequate modularity, step count, and yield associated with syntheses of existing ligands. Attaching the new ligands to quantum dots and dispersing them in a liquid crystal host affords hollow micron-sized capsules via nematic templating. The capsules resist thermal decomposition up to 350 °C — significantly higher than any previously reported microcapsules assembled from side-tethering calamitic ligand-functionalized nanoparticle. Evaluation of the capsules by small-angle X-ray scattering shows that interparticle spacing varies from 10–13 nm depending on the ligand used, and is correlated to aminoalkyl chain length.

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