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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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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I13-2-Diamond Manchester Imaging
Data acquisition
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Abstract: The virtual workshop on “X-ray Tomography at Synchrotron Facilities: Pipeline for Data Acquisition and Reduction” was held February 22–26, 2021, hosted by Elettra Sincrotrone Trieste (Italy) and organized through a joint collaboration between the Advanced Light Source (USA), the Advanced Photon Source (USA), the Diamond Light Source (UK), the European Synchrotron Radiation Facility (France), and Elettra Sincrotrone Trieste (Italy). The workshop was attended by 84 participants and animated by 22 speakers (see Figure 1). A total of 14 different synchrotron facilities were involved from Europe and the US as well as the SESAME synchotron Jordan (through the EC-funded project BEATS). In addition to the contributions from the organizer facilities, there was participation from SOLEIL (France), SSRL (USA), BESSY II (Germany), PETRA III (Germany), KARA (Germany), ALBA (Spain), MAX IV (Sweden), and the Swiss Light Source (Switzerland).
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Sep 2021
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Open Access
Abstract: To travel safely behind screens that can protect us from stones and hail, we must understand the response of glass to impact. However, without a means to observe the mechanisms that fail different silicate architectures, engineering has relied on external sensors, post-impact examination and best-guess to glaze our vehicles. We have used single and multi-bunch, X-ray imaging to differentiate distinct phases of failure in two silicates. We identified distinct micromechanisms, operating in tandem and leading to failure in borosilicate glass and Z-cut quartz. A surface zone in the amorphous glass densifies before bulk fracture occurs and then fails the block, whilst in quartz, fast cracks, driven down cleavage planes, fails the bulk. Varying the rate at which ejecta escapes by using different indenter tip geometries controls the failed target’s bulk strength. This opens the way to more physically based constitutive descriptions for the glasses allowing design of safer, composite panels by controlling the impulses felt by protective screens.
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Jun 2020
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Yuliang
Zhao
,
Weiwen
Zhang
,
Billy
Koe
,
Wenjia
Du
,
Mengmeng
Wang
,
Weilin
Wang
,
Elodie
Boller
,
Alexander
Rack
,
Zhenzhong
Sun
,
Da
Shu
,
Baode
Sun
,
Jiawei
Mi
Abstract: Scandium (Sc) has been long recognized as one of the most effective grain refining elements for Al alloys because of the Al3Sc phases formed in an Al melt containing Sc. However, there are still lack of comprehensive studies on the exact mechanism of how Al3Sc phases are nucleated in Al melt and their true 3D structures. In this paper, we used scanning/transmission electron microscopy and synchrotron X-ray tomography to study the nucleation and true 3D structure of primary Al3Sc phases in an Al-2wt%Sc alloy. The multiscale characterization approach revealed that the micrometre α-Al2O3 particles present in the Al melt can facilitate the formation of stacking faults at the α-Al2O3/Al3Sc interface and therefore promote heterogenous nucleation of Al3Sc phases. SEM and tomography clearly revealed that individual primary Al3Sc phases were simple cubes with the edge length of 10–35 μm; and majority of them were interconnected to form clusters with the peak value of 10,000 μm3. At the interface between an Al matrix and an Al3Sc cube, the Al3Sc phases can also grow into nanometre size particle clusters due to the depletion of Sc.
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Apr 2020
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Yingyue
Xu
,
Nan
Xia
,
Michelle
Lim
,
Xiaodong
Tan
,
Minh Ha
Tran
,
Erin
Boulger
,
Fei
Peng
,
Hunter
Young
,
Christoph
Rau
,
Alexander
Rack
,
Claus-Peter
Richter
Open Access
Abstract: An emerging method in the field of neural stimulation is the use of photons to activate neurons. The possible advantage of optical stimulation over electrical is attributable to its spatially selective activation of small neuron populations, which is promising in generating superior spatial resolution in neural interfaces. Two principal methods are explored for cochlear prostheses: direct stimulation of nerves with infrared light and optogenetics. This paper discusses basic requirements for developing a light delivery system (LDS) for the cochlea and provides examples for building such devices. The proposed device relies on small optical sources, which are assembled in an array to be inserted into the cochlea. The mechanical properties, the biocompatibility, and the efficacy of optrodes have been tested in animal models. The force required to insert optrodes into a model of the human scala tympani was comparable to insertion forces obtained for contemporary cochlear implant electrodes. Side-emitting diodes are powerful enough to evoke auditory responses in guinea pigs. Chronic implantation of the LDS did not elevate auditory brainstem responses over 26 weeks.
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Oct 2018
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Detectors
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Abstract: We report on indirect X-ray detector systems for various full-field, ultra high-speed X-ray imaging methodologies, such as X-ray phase-contrast radiography, diffraction topography, grating interferometry and speckle-based imaging performed at the hard X-ray imaging beamline ID19 of the European Synchrotron—ESRF. Our work highlights the versatility of indirect X-ray detectors to multiple goals such as single synchrotron pulse isolation, multiple-frame recording up to millions frames per second, high efficiency, and high spatial resolution. Besides the technical advancements, potential applications are briefly introduced and discussed.
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Apr 2018
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I12-JEEP: Joint Engineering, Environmental and Processing
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Donal P.
Finegan
,
Eric
Darcy
,
Matthew
Keyser
,
Bernhard
Tjaden
,
Thomas M. M.
Heenan
,
Rhodri
Jervis
,
Josh J.
Bailey
,
Nghia T.
Vo
,
Oxana V.
Magdysyuk
,
Michael
Drakopoulos
,
Marco Di
Michiel
,
Alexander
Rack
,
Gareth
Hinds
,
Dan J. L.
Brett
,
Paul
Shearing
Diamond Proposal Number(s):
[13884]
Open Access
Abstract: As the energy density of lithium-ion cells and batteries increases, controlling the outcomes of thermal runaway becomes more challenging. If the high rate of gas generation during thermal runaway is not adequately vented, commercial cell designs can rupture and explode, presenting serious safety concerns. Here, ultra-high-speed synchrotron X-ray imaging is used at >20 000 frames per second to characterize the venting processes of six different 18650 cell designs undergoing thermal runaway. For the first time, the mechanisms that lead to the most catastrophic type of cell failure, rupture, and explosion are identified and elucidated in detail. The practical application of the technique is highlighted by evaluating a novel 18650 cell design with a second vent at the base, which is shown to avoid the critical stages that lead to rupture. The insights yielded in this study shed new light on battery failure and are expected to guide the development of safer commercial cell designs.
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Oct 2017
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I12-JEEP: Joint Engineering, Environmental and Processing
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Donal P.
Finegan
,
Eric
Darcy
,
Matthew
Keyser
,
Bernhard
Tjaden
,
Thomas M. M.
Heenan
,
Rhodri
Jervis
,
Josh J.
Bailey
,
Romeo
Malik
,
Nghia T.
Vo
,
Oxana V.
Magdysyuk
,
Robert
Atwood
,
Michael
Drakopoulos
,
Marco
Dimichiel
,
Alexander
Rack
,
Gareth
Hinds
,
Dan J. L.
Brett
,
Paul R.
Shearing
Diamond Proposal Number(s):
[13884]
Open Access
Abstract: Lithium-ion batteries are being used in increasingly demanding applications where safety and reliability are of utmost importance. Thermal runaway presents the greatest safety hazard, and needs to be fully understood in order to progress towards safer cell and battery designs. Here, we demonstrate the application of an internal short circuiting device for controlled, on-demand, initiation of thermal runaway. Through its use, the location and timing of thermal runaway initiation is pre-determined, allowing analysis of the nucleation and propagation of failure within 18[thin space (1/6-em)]650 cells through the use of high-speed X-ray imaging at 2000 frames per second. The cause of unfavourable occurrences such as sidewall rupture, cell bursting, and cell-to-cell propagation within modules is elucidated, and steps towards improved safety of 18[thin space (1/6-em)]650 cells and batteries are discussed.
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Mar 2017
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Open Access
Abstract: Establishing the mineral content distribution in highly mineralized tissues, such as bones and teeth, is fundamental in understanding a variety of structural questions ranging from studies of the mechanical properties to improved pathological investigations. However, non-destructive, volumetric and quantitative density measurements of mineralized samples, some of which may extend several mm in size, remain challenging. Here, we demonstrate the potential of grating-based x-ray phase tomography to gain insight into the three-dimensional mass density distribution of tooth tissues in a non-destructive way and with a sensitivity of 85 mg/cm3. Density gradients of 13 − 19% over 1 − 2 mm within typical samples are detected, and local variations in density of 0.4 g/cm3 on a length scale of 0.1 mm are revealed. This method proves to be an excellent quantitative tool for investigations of subtle differences in mineral content of mineralized tissues that can change following treatment or during ageing and healing.
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Dec 2016
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