I13-2-Diamond Manchester Imaging
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Iain
Malone
,
Secil
Unsal
,
R. Scott
Young
,
Matthew P.
Jones
,
Francesco
Spanu
,
Shashidhara
Marathe
,
Rhodri
Jervis
,
Hugh G. C.
Hamilton
,
Christopher M.
Zalitis
,
Thomas S.
Miller
,
Alexander J. E.
Rettie
Diamond Proposal Number(s):
[35192]
Open Access
Abstract: Anion exchange membrane water electrolysers are held back by the low durability of the ionomer in the membrane and catalyst layers. Studying ionomer degradation in these systems is challenging because the main mechanisms - which result in catalyst detachment, membrane thinning, and loss of cationic functionality - have opposing effects on the cell potential. Electrochemical measurements alone are therefore insufficient for elucidating the underlying causes of degradation. To address this, a bespoke miniature-electrolyser-cell is developed for X-ray microtomography imaging of membrane electrode assemblies at 1.6 µm resolution. This setup enables the study of the entire active volume of the electrolyser under static and operando conditions and is validated against standard 5 cm2 laboratory cells. An operando investigation of degradation in Fumasep-based catalyst-coated membranes reveals both significant membrane thinning and loss of membrane ionic conductivity during stability testing, leading to increased ohmic resistance and cell potential. In contrast, a Selemion membrane shows minimal changes in thickness and conductivity and is significantly more stable compared to Fumasep when exposed to synchrotron radiation. This platform has relevance for operando studies of electrochemical materials and devices generally, including proton exchange membrane electrolysers, fuel cells, and CO2 electrolysers using both lab-based and synchrotron X-ray sources.
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Sep 2025
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I13-2-Diamond Manchester Imaging
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Matthew P.
Jones
,
Huw C. W.
Parks
,
Alice V.
Llewellyn
,
Hamish T.
Reid
,
Chun
Tan
,
Aaron
Wade
,
Thomas M. M.
Heenan
,
Francesco
Iacoviello
,
Shashidhara
Marathe
,
Paul R.
Shearing
,
Rhodri
Jervis
Diamond Proposal Number(s):
[28650]
Open Access
Abstract: During battery operation, cracking occurs in Nickel Manganese Cobalt (NMC) oxide secondary particles. Cracked particles appear darker in micro-computed tomography (micro-CT) images due to the partial volume effect, where voxels containing both void and solid yield intermediate grey-levels. This work presents an automated method for tracking grey-level changes caused by this effect in large, statistically meaningful micro-CT datasets containing over 10 000 individual particles. It extends earlier work using the GREAT algorithm to analyze NMC particles in tomography images. The new GREAT2 algorithm increases processing speed, from around 1,400 particles per day with GREAT to over 10 000 particles in under a minute. Furthermore, this work introduces methods for automated tracking of grey-level intensity changes in individual particles through different states of charge in an operando experiment. This capability enables temporal analysis of particle degradation mechanisms. Additional data processing methods are presented that extract useful insights. Through this work we show that the large sample sizes, enabled by this method and GREAT2, allow for statistically robust analysis of particle populations. These advances significantly accelerate the tomographic study of cracking in battery electrodes. The GREAT2 algorithm and associated workflows have been made available as the GRAPES Python toolkit.
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Jun 2025
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I13-2-Diamond Manchester Imaging
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Huw C. W.
Parks
,
Matthew
Jones
,
Aaron
Wade
,
Alice
Llewellyn
,
Chun
Tan
,
Hamish
Reid
,
Ralf
Ziesche
,
Thomas M. M.
Heenan
,
Shashidhara
Marathe
,
Christoph
Rau
,
Paul R.
Shearing
,
Rhodri
Jervis
Diamond Proposal Number(s):
[28650]
Open Access
Abstract: To understand fracture behaviour in battery materials, X-ray computed tomography (X-ray CT) has become the primary technique for non-destructive particle and crack analysis. Cracking causes performance decline in polycrystalline NMC811 by exposing new surfaces for parasitic electrolyte reactions and disconnecting active material from the electrode matrix. First cycle crack formation has been documented, but definitive electrochemically induced particle fracture is challenging to assess due to complex sample preparation and high-resolution X-ray imaging requirements. Presented here is an operando X-ray CT technique that enables accurate observation of fracture behaviour during de-/lithiation. A non-linear relationship between fracture behaviour and cell voltage was uncovered, and evidence of particle reformation during re-lithiation. Using a grey level analysis algorithm for fracture detection, we expedite damage evaluation in several thousands of particles throughout the electrochemical process, understanding crack initiation, propagation, and closure on a large, statistical scale and give the ability to track any one of the thousands of particles through its individual electrochemical history. Additionally, we explore the effects of continued volumetric hysteresis on particle damage. For the first time, we demonstrate the complex plurality of fracture behaviour in commercial lithium-ion battery materials, aiding in designing mitigation strategies against particle fracture.
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Mar 2025
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[25254]
Open Access
Abstract: The engineering of biochars with desired morphologies and pore structures is a far-reaching objective towards sustainable pore-dependent environmental technologies, such as water and soil remediation or catalysis. We hereby report a series of experiments that allow the direct following of the shape and porosity of single biochar particles during pyrolysis. Particles ~ 1–2 mm in diameter of unwashed and water-washed raw walnut shells were continuously 3D imaged during pyrolysis to 575 ℃ at a 10 K min−1 in Ar to obtain time- and temperature-resolved x-ray micro computed tomographies to a 0.82 μm resolution. Results showed visual evidence of a 30% and 70% v/v particle shrinkage for unwashed and washed samples, respectively. Particle swelling between 200 and 300 ℃ in the unwashed sample provided evidence of the softening of native biopolymers associated with lignin in untreated biomass. A purpose-defined parameter Λ shows the temperature-dependence of pore re-distribution towards the center of the particle to be linear for both samples. Λ was found to be in the washed sample, approximately 3.5 times faster than in the unwashed one. Such linear dependence is significantly slower than an exponential Arrhenius-like trend thereby providing a qualitative measure of the heat and mass transport phenomena limiting the chemical reactions in the porous medium. This evidence is key to resolving the pathways to the thermochemical decomposition of biomass leading to preparation of precision-engineered biochars.
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Oct 2024
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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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I12-JEEP: Joint Engineering, Environmental and Processing
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Arthur
Fordham
,
Zoran
Milojevic
,
Emily
Giles
,
Wenjia
Du
,
Rhodri E.
Owen
,
Stefan
Michalik
,
Philip A.
Chater
,
Prodip K.
Das
,
Pierrot S.
Attidekou
,
Simon M.
Lambert
,
Phoebe K.
Allan
,
Peter R.
Slater
,
Paul A.
Anderson
,
Rhodri
Jervis
,
Paul R.
Shearing
,
Dan J. I.
Brett
Diamond Proposal Number(s):
[27719]
Open Access
Abstract: The growing demand for electric vehicles (EVs) continues to raise concern for the disposal of lithium-ion batteries reaching their end of life (EoL). The cells inside EVs age differently depending on multiple factors. Yet, following extraction, there are significant challenges with characterizing degradation in cells that have been aged from real-world EV usage. We employed four non-destructive techniques—infrared thermography, ultrasonic mapping, X-ray tomography, and synchrotron X-ray diffraction—to analyze the aging of Nissan Leaf large-format pouch cells that were arranged in different orientations and locations within the pack. The combination of these methods provided complementary insights into cell degradation, with rotated/vertically aligned cells exhibiting distinct aging patterns compared with flat/horizontally aligned cells. These findings offer valuable information for pack design and demonstrate how cost-effective non-destructive techniques can provide practical assessment capabilities comparable to synchrotron studies. This approach enables decision support during EoL, enhancing battery production efficiency and minimizing material waste.
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Nov 2023
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I11-High Resolution Powder Diffraction
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Andrew Stephen
Leach
,
Alice
Llewellyn
,
Chao
Xu
,
Chun
Tan
,
Thomas M. M.
Heenan
,
Alex
Dimitrijevic
,
Karin
Kleiner
,
Clare P.
Grey
,
Dan J. L.
Brett
,
Chiu C.
Tang
,
Paul R.
Shearing
,
Rhodri
Jervis
Diamond Proposal Number(s):
[22498, 24122]
Open Access
Abstract: Understanding the performance of commercially relevant cathode materials for lithium-ion (Li-ion) batteries is vital to realize the potential of high-capacity materials for automotive applications. Of particular interest is the spatial variation of crystallographic behavior across (what can be) highly inhomogeneous electrodes. In this work, a high-resolution X-ray diffraction technique was used to obtain operando transmission measurements of Li-ion pouch cells to measure the spatial variances in the cell during electrochemical cycling. Through spatially resolved investigations of the crystallographic structures, the distribution of states of charge has been elucidated. A larger portion of the charging is accounted for by the central parts, with the edges and corners delithiating to a lesser extent for a given average electrode voltage. The cells were cycled to different upper cutoff voltages (4.2 and 4.3 V vs. graphite) and C-rates (0.5, 1, and 3C) to study the effect on the structure of the NMC811 cathode. By combining this rapid data collection method with a detailed Rietveld refinement of degraded NMC811, the spatial dependence of the degradation caused by long-term cycling (900 cycles) has also been shown. The variance shown in the pristine measurements is exaggerated in the aged cells with the edges and corners offering an even lower percentage of the charge. Measurements collected at the very edge of the cell have also highlighted the importance of electrode alignment, with a misalignment of less than 0.5 mm leading to significantly reduced electrochemical activity in that area.
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Jan 2022
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I12-JEEP: Joint Engineering, Environmental and Processing
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Matt
Sharp
,
John
Darst
,
Peter
Hughes
,
Julia
Billman
,
Martin
Pham
,
David
Petrushenko
,
Thomas
Heenan
,
Rhodri
Jervis
,
Rhodri Ellis
Owen
,
Drasti
Patel
,
Wenjia
Du
,
Harry
Michael
,
Alexander
Rack
,
Oxana
Magdysyuk
,
Thomas
Connolley
,
Dan
Brett
,
Gareth
Hinds
,
Matthew
Keyser
,
Eric
Darcy
,
Paul
Shearing
,
William Q.
Walker
,
Donal
Finegan
Diamond Proposal Number(s):
[24112, 20903, 17641]
Open Access
Abstract: Thermal runaway of lithium-ion batteries can involve various types of failure mechanisms each with their own unique characteristics. Using fractional thermal runaway calorimetry and high-speed radiography, the response of three different geometries of cylindrical cell (18650, 21700, and D-cell) to different abuse mechanisms (thermal, internal short circuiting, and nail penetration) are quantified and statistically examined. Correlations between the geometry of cells and their thermal behavior are identified, such as increasing heat output per amp-hour (kJ Ah-1) of cells with increasing cell diameter during nail penetration. High-speed radiography reveals that the rate of thermal runaway propagation within cells is generally highest for nail penetration where there is a relative increase in rate of propagation with increasing diameter, compared to thermal or internal short-circuiting abuse. For a given cell model tested under the same conditions, a distribution of heat output is observed with a trend of increasing heat output with increased mass ejection. Finally, internal temperature measurements using thermocouples embedded in the penetrating nail are shown to be unreliable thus demonstrating the need for care when using thermocouples where the temperature is rapidly changing. All data used in this manuscript are open access through the NREL and NASA Battery Failure Databank.
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Jan 2022
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B18-Core EXAFS
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Diamond Proposal Number(s):
[24178]
Open Access
Abstract: Nickel-rich cathodes (LiNixMnyCo1-x-yO2, x > 0.6) permit higher energy in lithium-ion rechargeable batteries but suffer from accelerated degradation at potentials above 4.1 V versus Li/Li+. Here, we present a proof-of-concept in situ pouch cell and methodology for correlative 2D synchrotron transmission X-ray microscopy with 3D lab-based micro-CT. XANES analysis of the TXM data enables tracking of Ni edge energy within and between the polycrystalline NMC811 particles embedded in the operating electrode through its initial delithiation. By using edge energy as a proxy, state-of-charge heterogeneities can be tracked at the nanoscale, revealing the role of cracked particles as potential nucleation points for failure and highlighting the challenges in achieving uniform (de-)lithiation. We propose, in future work, to leverage the pouch cell design presented here for longitudinal TXM-XANES studies of nickel-rich cathodes across multiple cycles and operating variables and investigate the effect of dopants and microstructural optimization in mitigating degradation.
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Nov 2021
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I20-EDE-Energy Dispersive EXAFS (EDE)
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Andrew S.
Leach
,
Jennifer
Hack
,
Monica
Amboage
,
Sofia
Diaz-Moreno
,
Haoliang
Huang
,
Patrick L.
Cullen
,
Martin
Wilding
,
Emanuele
Magliocca
,
Thomas
Miller
,
Christopher
Howard
,
Daniel
Brett
,
Paul
Shearing
,
Paul F.
Mcmillan
,
Andrea E.
Russell
,
Rhodri
Jervis
Diamond Proposal Number(s):
[22008, 15650]
Open Access
Abstract: A polymer electrolyte fuel cell (PEFC) has been designed to allow operando X-ray absorption spectroscopy (XAS) measurements of catalysts. The cell has been developed to operate under standard fuel cell conditions, with elevated temperatures and humidification of the gas-phase reactants, both of which greatly impact the catalyst utilisation. X-ray windows in the endplates of the cell facilitate collection of XAS spectra during fuel cell operation while maintaining good compression in the area of measurement. Results of polarisation curves and cyclic voltammograms (CVs) showed that the operando cell performs well as a fuel cell, while also providing XAS data of suitable quality for robust XANES analysis. The cell has produced comparable XAS results when performing a cyclic voltammogram to an established in situ cell when measuring the Pt LIII edge. Similar trends of Pt oxidation, and reduction of the formed Pt oxide, have been presented with a time resolution of 5 seconds for each spectrum, paving the way for time-resolved spectral measurements of fuel cell catalysts in a fully-operating fuel cell.
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May 2021
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