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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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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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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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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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[21587]
Open Access
Abstract: Accurate modelling of particle shrinkage during biomass pyrolysis is key to the production of biochars with specific morphologies. Such biochars represent sustainable solutions to a variety of adsorption-dependent environmental remediation challenges. Modelling of particle shrinkage during biomass pyrolysis has heretofore been based solely on theory and ex-situ experimental data. Here we present the first in-situ phase-contrast X-ray imaging study of biomass pyrolysis. A novel reactor was developed to enable operando synchrotron radiography of fixed beds of pyrolysing biomass. Almond shell particles experienced more bulk shrinkage and less change in porosity than did walnut shell particles during pyrolysis, despite their similar composition. Alkaline pretreatment was found to reduce this difference in feedstock behaviour. Ex-situ synchrotron X-ray microtomography was performed to study the effects of pyrolysis on pore morphology. Pyrolysis led to a redistribution of pores away from particle surfaces, meaning newly formed surface area may be less accessible to adsorbates.
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Jan 2021
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I13-1-Coherence
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Ana Katrina C.
Estandarte
,
Jiecheng
Diao
,
Alice
Llewellyn
,
Anmol
Jnawali
,
Thomas M. M.
Heenan
,
Sohrab R.
Daemi
,
Josh J.
Bailey
,
Silvia
Cipiccia
,
Darren
Batey
,
Xiaowen
Shi
,
Christoph
Rau
,
Dan J. L.
Brett
,
Rhodri
Jervis
,
Ian K.
Robinson
,
Paul
Shearing
Diamond Proposal Number(s):
[25852, 25440, 24129, 22373, 22309, 21652]
Abstract: Due to complex degradation mechanisms, disparities between the theoretical and practical capacities of lithium-ion battery cathode materials persist. Specifically, Ni-rich chemistries such as LiNi0.8Mn0.1Co0.1O2 (or NMC811) are one of the most promising choices for automotive applications; however, they continue to suffer severe degradation during operation that is poorly understood, thus challenging to mitigate. Here we use operando Bragg coherent diffraction imaging for 4D analysis of these mechanisms by inspecting the individual crystals within primary particles at various states of charge (SoC). Although some crystals were relatively homogeneous, we consistently observed non-uniform distributions of inter- and intracrystal strain at all measured SoC. Pristine structures may already possess heterogeneities capable of triggering crystal splitting and subsequently particle cracking. During low-voltage charging (2.7–3.5 V), crystal splitting may still occur even during minimal bulk deintercalation activity; and during discharging, rotational effects within parallel domains appear to be the precursor for the nucleation of screw dislocations at the crystal core. Ultimately, this discovery of the central role of crystal grain splitting in the charge/discharge dynamics may have ramifications across length scales that affect macroscopic performance loss during real-world battery operation.
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Dec 2020
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I14-Hard X-ray Nanoprobe
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Thomas M. M.
Heenan
,
Aaron
Wade
,
Chun
Tan
,
Julia E.
Parker
,
Dorota
Matras
,
Andrew S.
Leach
,
James B.
Robinson
,
Alice
Llewellyn
,
Alexander
Dimitrijevic
,
Rhodri
Jervis
,
Paul D.
Quinn
,
Dan J. L.
Brett
,
Paul R.
Shearing
Diamond Proposal Number(s):
[20841, 23858]
Open Access
Abstract: The next generation of automotive lithium‐ion batteries may employ NMC811 materials; however, defective particles are of significant interest due to their links to performance loss. Here, it is demonstrated that even before operation, on average, one‐third of NMC811 particles experience some form of defect, increasing in severity near the separator interface. It is determined that defective particles can be detected and quantified using low resolution imaging, presenting a significant improvement for material statistics. Fluorescence and diffraction data reveal that the variation of Mn content within the NMC particles may correlate to crystallographic disordering, indicating that the mobility and dissolution of Mn may be a key aspect of degradation during initial cycling. This, however, does not appear to correlate with the severity of particle cracking, which when analyzed at high spatial resolutions, reveals cracking structures similar to lower Ni content NMC, suggesting that the disconnection and separation of neighboring primary particles may be due to electrochemical expansion/contraction, exacerbated by other factors such as grain orientation that are inherent in such polycrystalline materials. These findings can guide research directions toward mitigating degradation at each respective length‐scale: electrode sheets, secondary and primary particles, and individual crystals, ultimately leading to improved automotive ranges and lifetimes.
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Nov 2020
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I11-High Resolution Powder Diffraction
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Open Access
Abstract: Renewable technologies, and in particular the electric vehicle revolution, have generated tremendous pressure for the improvement of lithium ion battery performance. To meet the increasingly high market demand, challenges include improving the energy density, extending cycle life and enhancing safety. In order to address these issues, a deep understanding of both the physical and chemical changes of battery materials under working conditions is crucial for linking degradation processes to their origins in material properties and their electrochemical signatures. In situ and operando synchrotron-based X-ray techniques provide powerful tools for battery materials research, allowing a deep understanding of structural evolution, redox processes and transport properties during cycling. In this review, in situ synchrotron-based X-ray diffraction methods are discussed in detail with an emphasis on recent advancements in improving the spatial and temporal resolution. The experimental approaches reviewed here include cell designs and materials, as well as beamline experimental setup details. Finally, future challenges and opportunities for battery technologies are discussed.
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Nov 2020
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