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Instruments / Technical Area	Publication Details	Published
I14-Hard X-ray Nanoprobe	Identifying the origins of microstructural defects such as cracking within Ni‐rich NMC811 cathode particles for lithium‐ion batteries 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 Advanced Energy Materials 1 DOI: 10.1002/aenm.202002655 Diamond Proposal Number(s): [20841, 23858] Open Access Show Abstract ▼ 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.	Nov 2020
I09-Surface and Interface Structural Analysis	Elucidating and mitigating degradation processes in perovskite light‐emitting diodes Zahra Andaji-garmaroudi , Mojtaba Abdi-jalebi , Felix U. Kosasih , Tiarnan Doherty , Stuart Macpherson , Alan R. Bowman , Gabriel J. Man , Ute B. Cappel , Hakan Rensmo , Caterina Ducati , Richard H. Friend , Samuel D. Stranks Advanced Energy Materials 11 DOI: 10.1002/aenm.202002676 Diamond Proposal Number(s): [22668] Show Abstract ▼ Abstract: Halide perovskites have attracted substantial interest for their potential as disruptive display and lighting technologies. However, perovskite light‐emitting diodes (PeLEDs) are still hindered by poor operational stability. A fundamental understanding of the degradation processes is lacking but will be key to mitigating these pathways. Here, a combination of in operando and ex situ measurements to monitor the performance degradation of (Cs0.06FA0.79MA0.15)Pb(I0.85Br0.15)3 PeLEDs over time is used. Through device, nanoscale cross‐sectional chemical mapping, and optical spectroscopy measurements, it is revealed that the degraded performance arises from an irreversible accumulation of bromide content at one interface, which leads to barriers to injection of charge carriers and thus increased nonradiative recombination. This ionic segregation is impeded by passivating the perovskite films with potassium halides, which immobilizes the excess halide species. The passivated PeLEDs show enhanced external quantum efficiency (EQE) from 0.5% to 4.5% and, importantly, show significantly enhanced stability, with minimal performance roll‐off even at high current densities (>200 mA cm−2). The decay half‐life for the devices under continuous operation at peak EQE increases from <1 to ≈15 h through passivation, and ≈200 h under pulsed operation. The results provide generalized insight into degradation pathways in PeLEDs and highlight routes to overcome these challenges.	Nov 2020
B21-High Throughput SAXS	Controlling photocatalytic activity by self‐assembly – tuning perylene bisimide photocatalysts for the hydrogen evolution reaction Daniel Mcdowall , Benjamin J. Greeves , Rob Clowes , Kate Mcaulay , Ana M. Fuentes‐caparrós , Lisa Thomson , Nikul Khunti , Nathan Cowieson , Michael C. Nolan , Matthew Wallace , Andrew I. Cooper , Emily R. Draper , Alexander J. Cowan , Dave J. Adams Advanced Energy Materials 10 DOI: 10.1002/aenm.202002469 Diamond Proposal Number(s): [20362] Open Access Show Abstract ▼ Abstract: Amino acid functionalized perylene bisimides (PBIs) form self‐assembled structures in solution, the nature of which depends on the local environment. Using a high‐throughput photocatalysis setup, five PBIs are studied for the hydrogen evolution reaction (HER) under a range of conditions (pH and hole scavenger concentration) across 350 experiments to explore the relationship between supramolecular structure and photocatalytic activity. Using small angle X‐ray scattering (SAXS), NMR spectroscopy and ultraviolet‐visible (UV‐vis) absorption spectroscopy, it is shown that photocatalytic activity is determined by the nature of the self‐assembled aggregate that is formed, demonstrating the potential of self‐assembly to tune activity. There is a clear correlation between the presence of charged flexible cylindrical aggregates and the occurrence of photocatalytic H2 production, with UV–vis spectroscopy indicating that the most active structure type has a distinctive form of π‐aggregation which is proposed to enable efficient charge separation across multiple PBI units.	Oct 2020
I15-1-X-ray Pair Distribution Function (XPDF)	Insights into the electrochemical reduction products and processes in silica anodes for next‐generation lithium‐ion batteries Jake E. Entwistle , Samuel G. Booth , Dean S. Keeble , Faisal Ayub , Maximilian Yan , Serena A. Corr , Denis J. Cumming , Siddharth V. Patwardhan Advanced Energy Materials 278 DOI: 10.1002/aenm.202001826 Diamond Proposal Number(s): [2257] Open Access Show Abstract ▼ Abstract: The use of silica as a lithium‐ion battery anode material requires a pretreatment step to induce electrochemical activity. The partially reversible electrochemical reduction reaction between silica and lithium has been postulated to produce silicon, which can subsequently reversibly react with lithium, providing stable capacities higher than graphite materials. Up to now, the electrochemical reduction pathway and the nature of the products were unknown, thereby hampering the design, optimization, and wider uptake of silica‐based anodes. Here, the electrochemical reduction pathway is uncovered and, for the first time, elemental silicon is identified as a reduction product. These insights, gleaned from analysis of the current response and capacity increase during reduction, conclusively demonstrated that silica must be reduced to introduce reversible capacity and the highest capacities of 600 mAh g−1 are achieved by using a constant load discharge at elevated temperature. Characterization via total scattering X‐ray pair distribution function analysis reveal the reduction products are amorphous in nature, highlighting the need for local structural methods to uncover vital information often inaccessible by traditional diffraction. These insights contribute toward understanding the electrochemical reduction of silica and can inform the development of pretreatment processes to enable their incorporation into next‐generation lithium‐ion batteries.	Sep 2020
B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS E01-JEM ARM 200CF	Multi‐scale investigations of δ‐Ni 0.25 V 2 O 5 ·nH 2 O cathode materials in aqueous zinc‐ion batteries Jianwei Li , Kit Mccoll , Xuekun Lu , Sanjay Sathasivam , Haobo Dong , Liqun Kang , Zhuangnan Li , Siyu Zhao , Andreas G. Kafizas , Ryan Wang , Dan J. L. Brett , Paul R. Shearing , Furio Corà , Guanjie He , Claire J. Carmalt , Ivan P. Parkin Advanced Energy Materials 8 DOI: 10.1002/aenm.202000058 Diamond Proposal Number(s): [24197, 22572] Show Abstract ▼ Abstract: Cost‐effective and environment‐friendly aqueous zinc‐ion batteries (AZIBs) exhibit tremendous potential for application in grid‐scale energy storage systems but are limited by suitable cathode materials. Hydrated vanadium bronzes have gained significant attention for AZIBs and can be produced with a range of different pre‐intercalated ions, allowing their properties to be optimized. However, gaining a detailed understanding of the energy storage mechanisms within these cathode materials remains a great challenge due to their complex crystallographic frameworks, limiting rational design from the perspective of enhanced Zn2+ diffusion over multiple length scales. Herein, a new class of hydrated porous δ‐Ni0.25V2O5.nH2O nanoribbons for use as an AZIB cathode is reported. The cathode delivers reversibility showing 402 mAh g−1 at 0.2 A g−1 and a capacity retention of 98% over 1200 cycles at 5 A g−1. A detailed investigation using experimental and computational approaches reveal that the host “δ” vanadate lattice has favorable Zn2+ diffusion properties, arising from the atomic‐level structure of the well‐defined lattice channels. Furthermore, the microstructure of the as‐prepared cathodes is examined using multi‐length scale X‐ray computed tomography for the first time in AZIBs and the effective diffusion coefficient is obtained by image‐based modeling, illustrating favorable porosity and satisfactory tortuosity.	Feb 2020
I15-1-X-ray Pair Distribution Function (XPDF)	Li2O:Li–Mn–O disordered rock‐salt nanocomposites as cathode prelithiation additives for high‐energy density Li‐ion batteries Maria Diaz-lopez , Philip A. Chater , Pierre Bordet , Melanie Freire , Christian Jordy , Oleg I. Lebedev , Valerie Pralong Advanced Energy Materials 142 DOI: 10.1002/aenm.201902788 Diamond Proposal Number(s): [20893] Open Access Show Abstract ▼ Abstract: The irreversible loss of lithium from the cathode material during the first cycles of rechargeable Li‐ion batteries notably reduces the overall cell capacity. Here, a new family of sacrificial cathode additives based on Li2O:Li2/3Mn1/3O5/6 composites synthesized by mechanochemical alloying is reported. These nanocomposites display record (but irreversible) capacities within the Li–Mn–O systems studied, of up to 1157 mAh g−1, which represents an increase of over 300% of the originally reported capacity in Li2/3Mn1/3O5/6 disordered rock salts. Such a high irreversible capacity is achieved by the reaction between Li2O and Li2/3Mn1/3O5/6 during the first charge, where electrochemically active Li2O acts as a Li+ donor. A 13% increase of the LiFePO4 and LiCoO2 first charge gravimetric capacities is demonstrated by the addition of only 2 wt% of the nanosized composite in the cathode mixture. This result shows the great potential of these newly discovered sacrificial additives to counteract initial losses of Li+ ions and improve battery performance.	Jan 2020
	Band Gap Dependence on Cation Disorder in ZnSnN 2 Solar Absorber Tim D. Veal , Nathaniel Feldberg , Nicholas Quackenbush , Wojciech M. Linhart , David O. Scanlon , Louis Piper , Steven M. Durbin Advanced Energy Materials 5 (24) DOI: 10.1002/aenm.201501462 Open Access Show Abstract ▼ Abstract: The band gap of earth-abundant ZnSnN2 can be tuned between 1 and 2 eV by varying the growth conditions and resulting cation disorder. The optical absorption edges and carrier densities fall between model curves for cation-ordered orthorhombic and disordered wurtzite ZnSnN2. Hard X-ray photoemission spectra suggest different degrees of cation disorder from comparison with hybrid DFT-calculated densities of states.	Dec 2015
	Lithiation-Induced Dilation Mapping in a Lithium-Ion Battery Electrode by 3D X-Ray Microscopy and Digital Volume Correlation David S. Eastwood , Vladimir Yufit , Jeff Gelb , Allen Gu , Robert Bradley , Stephen J. Harris , Daniel J. L. Brett , Nigel P. Brandon , Peter Lee , Philip Withers , Paul Shearing Advanced Energy Materials 4 (4) DOI: 10.1002/aenm.201300506 Show Abstract ▼ Abstract: Recent advances in high-resolution 3D X-ray computed tomography (CT) allow detailed, non-destructive 3D structural mapping of a complete lithium-ion battery. By repeated 3D image acquisition (time lapse CT imaging) these investigations of material microstructure are extended into the fourth dimension (time) to study structural changes of the device in operando. By digital volume correlation (DVC) of successive 3D images the dimensional changes taking place during charge cycling are quantified at the electrode level and at the Mn2O4 particle scale. After battery discharging, the extent of lithiation of the manganese (III/IV) oxide grains in the electrode is found to be a function of the distance from the battery terminal with grains closest to the electrode/current collector interface having the greatest expansion (≈30%) and grains furthest from the current collector and closest to the counter electrode showing negligible dilation. This implies that the discharge is limited by electrical conductivity. This new CT+DVC technique is widely applicable to the 3D exploration of the microstructural degradation processes for a range of energy materials including fuel cells, capacitors, catalysts, and ceramics	Mar 2014
I16-Materials and Magnetism	The Nanoscale Morphology of a PCDTBT:PCBM Photovoltaic Blend Paul Staniec , Andy Parnell , Alan Dunbar , Hunan Yi , Andrew Pearson , Paul Hopkinson , Tao Wang , Christy Kinane , R Dagliesh , Athene Donald , Anthony Ryan , Ahmed Iraqi , Richard Jones , David Lidzey Advanced Energy Materials DOI: 10.1002/aenm.201100144 Show Abstract ▼ Abstract: Neutron reflectivity and X-ray scattering have been used to characterise the structure of photovoltaic optimised PCDTBT:PCBM (1:4) blend films. A negative gradient of the PCBM forms spontaneously upon film casting a fortuitous structure that is well matched for efficient charge extraction. Mild thermal annealing at 70 °C does not significantly modify the film structure, and any improvement in device efficiency is likely to be through the removal of trapped casting solvent.	Apr 2011

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