I18-Microfocus Spectroscopy
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Thomas
Barthelay
,
Robert
Gray
,
Howard
Richards
,
Paloma
Rodriguez Santana
,
Sylvia
Britto
,
Kalotina
Geraki
,
Zhenyuan
Xia
,
Johanna
Xu
,
Leif E.
Asp
,
Chris
Bowen
,
Frank
Marken
,
Alexander
Lunt
,
Andrew
Rhead
Diamond Proposal Number(s):
[30127]
Open Access
Abstract: Structural batteries utilise the bifunctionality of carbon fibres to act as a load-bearing structure, but also as a conductive current collector for a battery electrode. Lithium-ion transport during the cycling of structural battery cathodes coated with different morphologies is investigated using Iron X-Ray Absorption Near Edge Spectroscopy (Fe XANES) and correlated to electrochemical performance. Two contrasting morphologies were produced using slurry coating and electrophoretic deposition (EPD) of lithium-iron phosphate (LFP) onto continuous carbon fibres. The ability to study the different structural battery cathode morphologies operando allows for a comparative analysis of their impact on cycling performance. The EPD-coated fibres exhibited a more homogeneous, thinner coating around the fibre compared to the thick, one-sided coating produced using slurry coating. Despite a lower initial capacity and 30 % lithium re-intercalation loss in the first cycle, EPD-coated fibres exhibited more stable capacity retention over time compared to slurry-coated counterparts. Electrochemical Impedance Spectroscopy (EIS) revealed initially high ionic resistance for the EPD-coated fibres, but a larger increase in resistance in the slurry coated electrodes over multiple cycles. This study demonstrated an innovative and novel method of analysing in greater detail, the cycling ability of the coated cathode material on carbon fibres using synchrotron radiation.
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Feb 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Donal P.
Finegan
,
Julia
Billman
,
Jacob
Darst
,
Peter
Hughes
,
Jesus
Trillo
,
Matt
Sharp
,
Alex
Benson
,
Martin
Pham
,
Inez
Kesuma
,
Mark
Buckwell
,
Hamish T.
Reid
,
Charlie
Kirchner-Burles
,
Matilda
Fransson
,
David
Petrushenko
,
Thomas M. M.
Heenan
,
Rhodri
Jervis
,
Rhodri
Owen
,
Drasti
Patel
,
Ludovic
Broche
,
Alexander
Rack
,
Oxana
Magdysyuk
,
Matt
Keyser
,
William
Walker
,
Paul
Shearing
,
Eric
Darcy
Diamond Proposal Number(s):
[24112, 20903, 17641]
Open Access
Abstract: The thermal response of Li-ion cells can greatly vary for identical cell designs tested under identical conditions, the distribution of which is costly to fully characterize experimentally. The open-source Battery Failure Databank presented here contains robust, high-quality data from hundreds of abuse tests spanning numerous commercial cell designs and testing conditions. Data was gathered using a fractional thermal runaway calorimeter and contains the fractional breakdown of heat and mass that was ejected, as well as high-speed synchrotron radiography of the internal dynamic response of cells during thermal runaway. The distribution of thermal output, mass ejection, and internal response of commercial cells are compared for different abuse-test conditions, which when normalized on a per amp-hour basis show a strong positive correlation between heat output from cells, the fraction of mass ejected from the cells, their energy- and power-density. Ejected mass was shown to contain 10 × more heat per gram than non-ejected mass. The causes of ‘outlier’ thermal and ejection responses i.e., extreme cases, are elucidated by high-speed radiography which showed how occurrences such as vent clogging can create more hazardous conditions. High-speed radiography also demonstrated how the time-resolved interplay of thermal runaway propagation and mass ejection influences the total heat generated.
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Mar 2024
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Álvaro
Tolosana-Moranchel
,
Alvaro
Garcia
,
Álvaro
García-Corral
,
José F.
Marco
,
Laura
Pascual
,
Dalia
Liuzzi
,
Mohamed A.
Salam
,
Pilar
Ferrer
,
Jorge
Torrero
,
David C.
Grinter
,
Georg
Held
,
Daniel
García Sánchez
,
K. Andreas
Friedrich
,
Maria
Retuerto
,
Sergio
Rojas
Diamond Proposal Number(s):
[30338]
Open Access
Abstract: The overall performance of proton exchange membrane fuel cells is limited by the sluggish kinetics of the oxygen-reduction reaction (ORR). Among the most active PGM-free ORR electrocatalysts are metal-nitrogen-carbon (M-N-C), such as Fe–N–C. The Fe–N4 ensembles in these PGM-free catalysts, present in different configurations, are proposed to be the active sites for the ORR in acid. In this work, we have synthesized a Fe/N/C catalyst via thermal treatment of a polymeric CxNy precursor obtained by the wet-polymerization of melamine (a nitrogen rich molecule) and terephthaldehyde. The materials obtained (Im-FeNC-1HT and Im-FeNC-2HT) display high ORR activity in acid electrolyte compared to other Fe–N–C catalysts prepared with precursors different than 2-methylimidazole or ZIF-8. Characterization data indicate the formation of high- and low-spin Fe-Nx ensembles, with a site density of 4.4·1019 sitesFe·g−1 estimated by electrochemical stripping of NO. The ORR activity was evaluated in a RRDE configuration in 0.1 M HClO4 and in MEA configuration in a single cell.
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Sep 2023
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I15-1-X-ray Pair Distribution Function (XPDF)
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Zhimin
Chen
,
Tao
Du
,
Søren S.
Sørensen
,
Rasmus
Christensen
,
Qi
Zhang
,
Lars R.
Jensen
,
Oxana
Magdysyuk
,
Maria
Diaz-Lopez
,
Mathieu
Bauchy
,
Yuanzheng
Yue
,
Morten M.
Smedskjaer
Diamond Proposal Number(s):
[30401]
Open Access
Abstract: Glass materials are potential candidates as solid electrolytes for batteries, but the atomistic origins of the variations in their properties and functionalities with composition are not well understood. Here, based on combined experimental and simulation techniques, we investigate the structural origin of the variation in fracture toughness and ionic conductivity of lithium borophosphate glass electrolytes with varying compositions. We focus on these properties since they are critically important for mechanical stability and electrochemical performances of glassy electrolytes. To this end, we have performed molecular dynamics simulations combined with X-ray total scattering experiments to provide the atomic picture of the disordered structure of borophosphate glass. The mechanical properties have been characterized through single-edge precracked beam measurements and axial tensile simulations. We find that the deformation and fracture behaviors of the electrolytes are governed by bond switching events of boron, which dissipate the strain energy during fracture. The migration of lithium ions in the electrolyte network is facilitated by hopping between superstructural rings, which reflects the important role of medium-range order structure in determining the lithium-ion diffusion. These findings have important implications for the design of future glassy electrolytes.
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Nov 2022
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I08-Scanning X-ray Microscopy beamline (SXM)
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Diamond Proposal Number(s):
[26226]
Open Access
Abstract: Batteries with inorganic solid-state electrolytes (ISSE) are attracting notable interest for next-generation systems implementing Lithium (Li) metal anodes, in view of achieving higher energy densities combined with superior safety. Notwithstanding extensive research and development work, this technology is not yet ready for industrial implementation, one of the key challenges being the stability of ISSEs, chiefly at the anodic interface. This work attacks this issue for the specific case of the LAGP/Li (Lithium Aluminium Germanium Phosphate/Lithium) interface with a micro-spectroscopic approach centred on post mortem Scanning Transmission X-ray Microscopy (STXM) of intact LMO/LAGP/Li thin-film batteries, microfabricated in discharged state. Pristine and cycled cells were mapped to pinpoint morphochemical changes, induced by electrochemical ageing. The evidenced shape changes, corresponding to mechanical damaging of the solid/solid electrodic interfaces correlate with LAGP decomposition at the anode, leading to reduction of Ge, whereas the chemical state at the cathodic interface is preserved. Thanks to its submicron spacial resolution, the STXM at the Ge L-edge and O K-edge spectra allowed to assess the highly localized nature of the chemical transformation of LAGP and its correlation with the formation of Li outgrowth features.
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Nov 2022
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D.
Matras
,
T. E.
Ashton
,
H.
Dong
,
M.
Mirolo
,
I.
Martens
,
J.
Drnec
,
J. A.
Darr
,
P. D.
Quinn
,
S. D. M.
Jacques
,
A. M.
Beale
,
A.
Vamvakeros
Abstract: Synchrotron X-ray diffraction computed tomography (XRD-CT) was employed to study a commercial 18650 cylindrical LiNi0.8Co0.15Al0.5O2 (NCA) battery under operating conditions and during seven cycles. The analysis of the spatially-resolved diffraction patterns revealed multiple chemical heterogeneities related to the lithium distribution in both the cathode and the anode. It is shown that during the charging of the battery, the anode exhibits different degrees of activity regarding the lithiation process. Explicitly, the following three regions were identified: a uniform/homogenous lithiation, a delayed lithiation and an inactive-to-lithiation region. The inactive-to-lithiation anode region was a result of the specific cell geometry (i.e. due to lack of cathode tape opposite these anode areas) and throughout the cycling experiments remained present in the form of LiC30-30+. The delayed lithiation region was seen to have a direct impact on the properties of NCA in its close proximity during the battery discharging, preventing its full lithiation. Further to this, the aluminum tab negatively affected the NCA in direct contact with it, leading to different lattice parameter a and c evolution compared to the rest of the cathode.
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Aug 2022
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I08-1-Soft X-ray Ptychography
I08-Scanning X-ray Microscopy beamline (SXM)
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Diamond Proposal Number(s):
[22398]
Open Access
Abstract: Sustainability, environmental and safety concerns raised by the increasing demand of batteries are driving research towards post-lithium technologies. Rechargeable Zn batteries are strong candidates, but still not practically viable, owing to the extensively studied, but poorly understood unstable behavior of Zn metal upon discharge-charge cycling. This limiting factor warrants more fundamental investigations and the present report provides the lacking molecular-level information on the Zn-based compounds forming at the electrode/electrolyte interface as a result of electrochemical cyclic in weakly acidic aqueous electrolyte. The results are obtained using ex situ X-ray absorption spectromicroscopy maps, modelled mathematically and complemented with cyclic voltammetry, symmetric-cell tests and electron microscopy. We have identified the role of the zincate precipitation resulting from local alkalinization during recharge, combined with additional zincate formation and decomposition to zinc oxide during discharge. The mathematical model allowed a transparent interpretation of morphochemical changes observed. The synergy of these processes leads to electrochemical localization effects, resulting in the formation of a complexly structured and low conductive ZnO-based template, that might play a role in driving shape changes.
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Mar 2022
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I12-JEEP: Joint Engineering, Environmental and Processing
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William Q.
Walker
,
Kylie
Cooper
,
Peter
Hughes
,
Ian
Doemling
,
Mina
Akhnoukh
,
Sydney
Taylor
,
Jacob
Darst
,
Julia
Billman
,
Matthew
Sharp
,
David
Petrushenko
,
Rhodri
Owen
,
Martin
Pham
,
Thomas
Heenan
,
Alexander
Rack
,
Oxana
Magdysyuk
,
Thomas
Connolley
,
Dan
Brett
,
Paul
Shearing
,
Donal
Finegan
,
Eric
Darcy
Diamond Proposal Number(s):
[24112, 20903, 17641]
Abstract: Consideration of thermal runaway heat output variability is paramount for the development of safe lithium-ion battery assemblies. This study utilizes data gathered from fractional thermal runaway calorimetry (FTRC) experiments to conduct a comparative analysis of thermal runaway heat output for three cell formats (18650, 21700, and 33600) as a function of trigger method (heaters, internal short-circuiting device, and nail penetration). The analysis is based on comparisons for the calculated total energy yield, fractional energy yield, heat rate, and heat flux. This study reveals that nail penetration tends to result in higher thermal runaway heat output for larger cells (21700 & 33600); these experiments also tended to result in higher fractions of the total energy being released through the cell body. The smaller cells (18650) did not appear to have significant variation in heat output as a function of trigger method. This finding suggests that, for this cell type, worst-case scenario heat output could be achievable in assembly level testing regardless of the utilized trigger method. This study also demonstrates successful translation of FTRC results, as recorded in the Battery Failure Databank, into meaningful analysis that breaks down the influence of specific conditions on thermal runaway heat output.
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Mar 2022
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Isabel
Rodríguez-García
,
Dmitry
Galyamin
,
Laura
Pascual
,
Pilar
Ferrer
,
Miguel A.
Peña
,
David
Grinter
,
Georg
Held
,
Mohamed
Abdel Salam
,
Mohamed
Mokhtar
,
Katabathini
Narasimharao
,
Maria
Retuerto
,
Sergio
Rojas
Diamond Proposal Number(s):
[28150]
Open Access
Abstract: Ru mixed oxides are the most active catalysts for the oxygen evolution reaction (OER) in acid electrolyte. However, their stability is seriously compromised during the reaction. In this work we show that it is possible to enhance both OER activity and durability of SrRuO3 mixed oxide by the partial doping with K+ in Sr2+ sites. Sr1-xKxRuO3 perovskites (x = 0.00, 0.05, 0.10 and 0.20) have been synthesized by wet chemistry. The partial doping with K+ cations led to oxides with Ru atoms in a higher oxidation state. In addition, K-doping resulted in perovskites with slightly higher symmetry. The performance of the K-doped perovskites for the OER was assessed in acid electrolyte. Clearly, the K-doped materials, especially Sr0.80K0.20RuO3, display higher activity (lower E10) and significantly higher durability than the undoped sample SrRuO3. The results indicate that chemical modifications on Ru perovskites can be a suitable strategy to improve the stability of Ru phases during the OER.
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Feb 2022
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B18-Core EXAFS
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Diamond Proposal Number(s):
[22152]
Abstract: Fe–N–C aerogel catalysts were prepared by sol–gel polycondensation of resorcinol, melamine and formaldehyde precursors in the presence of FeCl3 salt, followed by supercritical drying and thermal treatments. The effect of the mass ratio of precursors on the microstructure, iron speciation and oxygen reduction reaction (ORR) performance of the Fe–N–C aerogels was investigated by N2 sorption, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, X-ray absorption spectroscopy, CO chemisorption and rotating disk electrode in acidic medium. The best ORR performance (activity and mass transport) was obtained by an optimum balance between pore structure and active Fe-Nx species. Through acid washing, the durability of the catalyst was further improved by eliminating unstable and inactive species, particularly iron nanoparticles and iron carbide. From the CO chemisorption and turnover-frequency value, the surface sites were comparable with the highest values reported in literature. Finally, Fe–N–C aerogel catalyst was implemented a in membrane–electrode assembly with an active area of 25 cm2 and tested in single cell, emphasizing the importance of the ink formulation on the performance.
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Dec 2021
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