I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[33667]
Open Access
Abstract: The use of conventional zirconium alloys at temperatures above 400 °C is limited by high temperature strength and creep resistance. This has prevented the consideration of zirconium alloys for fusion and Generation IV fission plant designs operating at 500 °C–1000 °C. The physical metallurgy of zirconium is similar to titanium which has seen alloying advances allowing application temperatures up to 600 °C. Although the oxidation resistance of zirconium-based alloys is expected to be poor, in a water environment, new Generation-IV and fusion reactors are designed to operate using alternative coolants such as liquid metals and molten salts. Therefore, a new class of zirconium alloys in the Zr-Al-Sn-(Si,Cr,V) system, designed by analogy to near-
titanium alloys, were synthesised by arc melting and processed in a sequence of homogenisation, hot/cold rolling, recrystallisation, and ageing treatments. Microscopy and diffraction identified a refined fully lath grain structure reinforced by nanoscale lamellar or discrete coherent Zr3Al precipitates, with morphology and crystal structure differing with ageing times. Additionally alloying with Si, Cr, and V respectively leads to Zr2Si, ZrCr2, and ZrV2 incoherent precipitates. Tensile testing revealed a strengthening effect by Al, but with significant changes to ductility on ageing depending on the evolution of Zr3Al. Creep testing showed creep rates orders of magnitude better than conventional Zircaloy-4 and nuclear ferritic/martensitic steels, approaching near-
Ti alloys. The present work offers new insights and perspectives into how high-temperature zirconium alloys might be designed to meet the requirements for fusion and Gen-IV fission.
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Mar 2026
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I15-Extreme Conditions
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Vasiliki
Faka
,
Mohammed
Alabdali
,
Martin A.
Lange
,
Franco M.
Zanotto
,
Can
Yildirim
,
Mikael Dahl
Kanedal
,
Jędrzej
Kondek
,
Matthias
Hartmann
,
Oliver
Maus
,
Dominik
Daisenberger
,
Michael Ryan
Hansen
,
Jozef
Keckes
,
Daniel
Rettenwander
,
Alejandro
Franco
,
Wolfgang G.
Zeier
Diamond Proposal Number(s):
[36607]
Open Access
Abstract: Solid-state battery fabrication requires the densification of solid electrolytes to achieve optimal cycling performance and high energy density. However, the underlying compaction mechanisms of these electrolytes remain poorly understood. Here, we investigate the effect of pressure consolidation on the ionic conductor Li6PS5Cl with particle size distributions (PSD) ranging from 4 to 40 µm. Heckel analysis reveals that samples with smaller PSDs exhibit higher compressibility at lower pressures. X-ray diffraction peak profiling shows that applied pressure induces lattice strain, leading to peak broadening, while pair distribution function analysis demonstrates a reduction in coherence length upon pressing. Dark-field X-ray microscopy further provides spatially resolved orientation maps, uncovering intragranular structural variations within individual Li6PS5Cl agglomerates after compression. To better understand the origin of stress fluctuations, we performed discrete element method simulations using the experimental PSDs. The results indicate that smaller particles and broader PSDs experience higher stresses, whereas monodisperse systems do not exhibit significant stress fluctuations with position or particle size. This suggests that the high strain observed cannot be attributed solely to smaller particles, but rather to size inhomogeneity. Overall, these findings highlight that both particle size and its distribution play a critical role in processing solid electrolytes for solid-state batteries.
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Jan 2026
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[33261]
Open Access
Abstract: Lithium metal (LM) and zero-excess lithium (ZE) anodes offer pathways to increase the energy density of all-solid-state batteries (ASSBs). We employ operando X-ray computed tomography combined with an image subtraction method to visualize lithium plating/stripping morphology, stack mechanical failure, and quantify the lithium reversibility in asymmetric Li6PS5Cl (LPSC)-based ASSBs. Lithium metal counter electrode (CE) and copper (Cu) working electrode (WE) emulate LM and ZE interface configurations, respectively. We compare bare Cu and silver-coated Cu (Ag/Cu) WEs under varying current densities. At 0.25 mA cm−2(WE), bare Cu shows edge-localized and non-uniform lithium deposition, while Ag/Cu facilitates more uniform lithium spreading, but results in higher first-cycle irreversibility and lower Coulombic efficiency. Above 0.5 mA cm−2(WE), failure in Li|LPSC|Cu cells initiate at the LPSC|Cu interface via spallation cracks. In contrast, Ag preserves interface integrity at the WE despite lithium initially plates at discrete nucleation spots. However, failure shifts to the Li|LPSC interface, where non-uniform lithium depletion at the CE exposes the underlying Cu, leading to spallation cracks upon subsequent plating. Mechanical finite element simulations support these observations and underscore the critical role of the nucleation layers in mitigating mechanical failure. This study highlights interface engineering as a key strategy to address electro-chemo-mechanical degradation in LM- and ZE-ASSBs.
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Jan 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[33569]
Open Access
Abstract: Green hydrogen production is limited by the thermodynamic energy requirement of water splitting. By decoupling the anodic and cathodic reactions using redox mediators, alternative feedstocks such as lignocellulosic biomass can yield comparable hydrogen purity with around half the total electrical energy input of conventional water electrolysis. Keggin-type heteropolyacids such as phosphomolybdic acid (H3PMo12O40) are increasingly of interest as mediators in decoupled electrochemical energy conversion applications, due to their reversible redox characteristics. However, the redox behaviour of heteropolyacids in aqueous solution during this process is still poorly understood. X-ray absorption spectroscopy (XAS) techniques offer the opportunity to directly probe changes in oxidation state and local structure of the mediator in-operando, allowing unprecedented insight into redox processes in a flow cell environment. Here, for the first time, we demonstrate operando XAS of reduced phosphomolybdic acid as it undergoes oxidation in a proton exchange membrane electrolyser with bespoke 3D-printed flow-fields. Changes in the time-resolved XAS were correlated to structural changes in the Keggin anion, which were closely related to the state-of-charge of the mediator, laying the groundwork for future studies of solution-phase Keggin-type heteropolyacid redox states. Furthermore, reduction of the phosphomolybdic acid via mild thermal digestion of either pure lignin or real agricultural biowaste is compared, in a step towards real-world applications. This work contributes significantly to the efficient and low-cost production of green hydrogen from waste biomass feedstocks, as well as providing insights into similar decoupled electrolysis processes.
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Jan 2026
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B18-Core EXAFS
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Run
Ran
,
Haoliang
Huang
,
Qingqing
Chen
,
Fei
Lin
,
Zhipeng
Yu
,
Weifeng
Su
,
Chenyue
Zhang
,
Qingsen
Jia
,
Jingwei
Wang
,
Yang
Zhao
,
Kaiyang
Xu
,
Binwen
Zeng
,
Yaowen
Xu
,
Weimian
Zhang
,
Zhijian
Peng
,
Lifeng
Liu
Diamond Proposal Number(s):
[36104]
Abstract: Sulfur quantum dots (SQDs) represent an emerging class of metal-free, biocompatible luminescent nanomaterials, yet their synthesis remains challenged by harsh conditions, high energy consumption, and limited scalability. Herein, we report a highly value-added strategy coupling SQD synthesis with hydrogen production through sulfion (S2−) oxidation reaction (SOR) assisted alkaline-modified seawater electrolysis (SWE). Such coupling substantially lowers the energy demand for electrolysis and effectively circumvents the interfering chlorine evolution at the anode. An efficient and stable cobalt single-atom catalyst (Co-SAs-PNC) is developed to boost SOR, achieving a large current density of 500 mA cm−2 at 0.536 V vs. reversible hydrogen electrode in alkaline-modified natural seawater and operating stably for 116 h. A flow cell comprising Co-SAs-PNC as the anode catalyst and commercial Pt/C as the cathode catalyst requires only 1.01 V to reach 500 mA cm−2 and shows outstanding durability of >450 h. Besides valuable hydrogen generated at the cathode, the polysulfides electrochemically derived at the anode can be readily converted to multicolor photoluminescent SQDs. Comprehensive in situ/operando experiments and theoretical calculations elucidate the SOR mechanism at isolated Co sites. This work not only opens a new avenue for sustainable SQD production but also remarkably enhances the economic viability of the SWE technology.
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Jan 2026
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I12-JEEP: Joint Engineering, Environmental and Processing
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Sam
Riley
,
Antonios
Vamvakeros
,
Gustavo
Quino
,
John
Morley
,
Mengzheng
Ouyang
,
Andrew
Shevchuk
,
Kehan
Huang
,
Pierre-Olivier
Autran
,
Stefan
Michalik
,
Genoveva
Burca
,
Billy
Wu
,
Nigel
Brandon
,
Chandramohan
George
Diamond Proposal Number(s):
[36699]
Open Access
Abstract: Understanding the strain tolerance of both standard and mechanically flexible battery electrodes is prerequisite for optimizing performance, safety, and longevity, particularly in heavy-duty applications, flexible electronics and wearables. Achieving this requires a deeper understanding of how mechanical strain drives electrode degradation. In this work, we directly compare the strain response of electrospun (flexible) and slurry-cast (conventional) electrodes. To simulate acute mechanical stress, electrodes underwent a controlled 180° folding, pressing, and unfolding protocol designed to induce measurable damage, we then employed a combination of characterization techniques, including synchrotron X-ray nano-computed tomography, X-ray diffraction mapping, electrochemical analysis, and in situ Tensiometer-scanning electron microscopy to assess both structural and electrochemical degradation modes and provide a standardised upper-bound for strain induced damage. Our results reveal that electrospun electrodes exhibit significantly greater resilience to deformation, attributed to their freestanding architecture and fibrous morphology. These findings underscore the importance of characterizing deformation mechanisms to guide the design of high-performance batteries.
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Jan 2026
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B18-Core EXAFS
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Diamond Proposal Number(s):
[34446]
Open Access
Abstract: Understanding the redox behavior and structural stability of aliovalent substituents in ionic conductors is critical, as their variable oxidation states can inadvertently introduce electronic conductivity and alter transport mechanisms under different atmospheric conditions. Here, we report the atmosphere-dependent redox behavior and local coordination of Mo in LaNb0.9Mo0.1O4.05, focusing on its influence on phase transition and transport properties, where the as-sintered LaNb0.9Mo0.1O4.05 was systematically annealed under pure O2, pure N2, vacuum (∼1.6 × 10–8 mbar), and 5% H2/N2 at 800 °C for different dwell times. Electron paramagnetic resonance (EPR) spectroscopy results demonstrate the emergence of Mo5+ under 5% H2/N2. In situ X-ray absorption near edge structure (XANES) measurements reveal the reversible redox behavior of Mo, where Mo5+ formed under 5% H2/N2 reoxidizes to Mo6+ upon exposure to static air, while complementary in situ extended X-ray absorption fine structure (EXAFS) analysis shows that the Nb coordination environment also transitions from prototypical LaNbO4 structure under reducing conditions back to the Mo-substituted LaNbO4 structure upon reoxidation. This change of the oxidation states of Mo could correspondingly alter the band structure of the sample, which further enhances charge transport: the sample annealed in 5% H2/N2 for 24 h exhibits a reduced activation energy and increased electronic conductivity. These results highlight a strong coupling among substituent redox flexibility, local structure, and transport properties, providing an understanding of tailoring the properties of ionic conductors through controlled redox environments.
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Dec 2025
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E02-JEM ARM 300CF
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Xinjuan
Li
,
Zhao
Jiang
,
Si
Chen
,
Yi
Tang
,
Bofeng
Xue
,
Tianhao
Wu
,
Yang
Lu
,
Xavier
Moya
,
Akshay
Rao
,
Zhongzheng
Yu
,
Caterina
Ducati
Diamond Proposal Number(s):
[39081]
Open Access
Abstract: Perovskite quantum dots (PeQDs) offer high photoluminescence quantum efficiencies, precise spectral tunability, and solution-processability, making them promising for advanced optoelectronics. However, their structural and defect evolution under thermal stress remains poorly understood. Here, direct nanoscale insights are provided into temperature-driven phase transition and defect dynamics in CsPbBr3 PeQDs using high-resolution, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images, 4D STEM, and photoluminescence spectroscopy. Sub-ångström imaging at room temperature reveals inherent atomic features and octahedral tilting of the lead halide perovskite lattice in PeQDs, suggesting a pre-tilted, low-symmetry state before thermal perturbation. The cryogenic cooling induces a reversible orthorhombic-to-monoclinic phase transition, distinct from bulk perovskite behavior and accompanied by severe strain localization exceeding 20% at surfaces and grain boundaries. A controlled cryogenic post-synthesis treatment can effectively heal defects and improve radiative recombination, whereas prolonged cryo-treatment introduces irreversible structural degradation. These findings highlight the intrinsic structural flexibility of PeQDs and provide a scalable post-synthesis treatment method to optimize the stability and efficiency of QDs for various optoelectronic applications.
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Dec 2025
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Daniel J.
Zheng
,
Kaylee
Mccormack
,
Jiayu
Peng
,
Raul
Garcia-Diez
,
Elmar Yu
Kataev
,
Fabian
Schwarz
,
Susan
Nehzati
,
Jakob
Thyr
,
Wilson
Quevedo-Garzon
,
Benjamin
Howchen
,
Marcus
Bär
,
Yuriy
Román-Leshkov
,
Yang
Shao-Horn
,
Mikaela
Görlin
Abstract: The oxygen evolution reaction (OER) is crucial for electrofuel production. Metal–hydroxide organic frameworks (MHOFs), a subset of metal–organic frameworks with oxyhydroxide-like layers interconnected via organic linkers, have shown great promise as OER electrocatalysts. This study investigates lattice oxygen exchange in four Ni- and Fe-substituted MHOFs with varying linker stabilities using 18O isotope labeling combined with operando Raman spectroscopy. A negative correlation between 18O/16O lattice oxygen exchange and the OER activity is shown, with Fe ions further suppressing exchange. Operando X-ray spectroscopy (XAS) and UV–vis further reveals that lattice oxygen exchange primarily proceeds on reduced Ni2+ sites, with higher linker stability preserving more Ni2+ sites and promoting greater lattice oxygen exchange. Supported by density functional theory, the MHOF surface transforms into an OER-active MOxHy-like phase, explaining the negative correlation of lattice exchange with the OER activity. This work also identifies a noninnocent role of the Raman laser in inducing lattice oxygen exchange and offers critical insights into various lattice oxygen exchange pathways in MHOFs, demonstrating their distinction from the catalytic lattice oxygen evolution reaction mechanism.
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Dec 2025
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[36397]
Abstract: The widespread adoption of Li-ion batteries has created a pressing need for effective recycling strategies. A common approach involves producing “black mass”─a mixture of shredded electrode materials─followed by thermal treatment to simplify downstream recovery. Although current collectors (Al and Cu foils) are assumed to be physically separated before pyrolysis, industrial separation is often incomplete, leaving residual foil fragments that can chemically react with cathode materials. Here we investigate the influence of these foils on black mass pyrolysis using simplified model systems composed of pristine LiNi0.8Mn0.1Co0.1O2 and current collector fragments under inert, mildly oxidizing, and reducing atmospheres. Cu foils were found to form lithium copper oxides, LiCuO and Li2CuO2, previously unreported in the Li-ion battery recycling literature. Al foils produced γ-LiAlO2, Li5AlO4, and LiAl2(OH)7·2H2O. The two latter phases readily decompose to γ-LiAlO2, a compound that has been suggested to be detrimental for Li recovery due to its low solubility. We assess the leaching implications of these product phases, with particular attention to γ-LiAlO2, to establish that they readily dissolve in dilute H2SO4/H2O2 solutions, but can reduce Ni and Co leaching efficiency in more realistic black mass mixtures.
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Dec 2025
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