I15-1-X-ray Pair Distribution Function (XPDF)
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Zixuan
Li
,
Rui
Qi
,
Yi
Yuan
,
Lechen
Yang
,
Lijiang
Song
,
Ashok S.
Menon
,
Louis F. J.
Piper
,
Didier
Wermeille
,
Paul
Thompson
,
Robert A.
House
,
Peter G.
Bruce
,
Alex W.
Robertson
Open Access
Abstract: Aqueous zinc-ion batteries (ZIBs) suffer from sustained capacity loss at the zinc metal anode due to side reactions with the electrolyte, even under idle conditions. The concept of an anode-free ZIB would address this degradation by eliminating the metal anode source. A key requirement for such systems is a cathode that contains zinc in its pristine state and supports initial charging. Here, we report the synthesis and characterization of cation-disordered rocksalt (DRX) ZnMnO2, a new cathode material suitable for anode-free ZIBs. ZnMnO2 meets the essential criteria for anode-free operation of natively containing Zn in the pristine state, enabling an initial charge, as well as offering high initial charge capacity (312.8 mAh g−1), and discharge voltage (1.36 V). We show that the dominant energy storage mechanism involves Mn dissolution and redeposition, with a smaller contribution arising from reversible Zn intercalation into a spinel phase that forms in situ during cycling. We further demonstrate the versatility of DRX cathodes by extending the concept to ZnFeO2. These findings establish DRX materials as a promising platform for the development of cathodes suitable for anode-free ZIBs.
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Oct 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Bartholomew T.
Payne
,
Mikkel
Juelsholt
,
Miguel A.
Pérez-Osorio
,
Dominic L. R.
Melvin
,
Gabriel J.
Cuello
,
Emmanuelle
Suard
,
Daniel J. M.
Irving
,
Nicholas
Rees
,
Mark
Feaviour
,
Enrico
Petrucco
,
Stephen
Day
,
Gregory J.
Rees
,
Peter G.
Bruce
Open Access
Abstract: The rate performance of all-solid-state batteries can be limited by the low conductivity of the solid electrolyte in the composite cathode. A conductivity of 10 mS cm⁻¹ is required, which exceeds that of many solid electrolytes. This limitation can be attributed to intra- and inter-grain ion transport. Understanding the limitations of ion transport is a multi-length scale problem ranging from single bond hops to particle-particle transport. Here we show that spark plasma sintering of Li6PS5Cl not only enhances ion transport on the macroscopic length scale but also on the microscopic scale. On the macroscopic length scale, greater densification improves particle-to- particle contact. On the nanoscale, short-range order (SRO) of the neighbouring 4a/4a and 4d/4d Wyckoff sites present in the cold-pressed Li6PS5Cl produces unfavourable Li ion pathways through the cell. Spark plasma heating removes the SRO, creating a connected network of microscopic pathways for the Li to migrate. Finally, on the atomistic level, spark plasma heating increases the amount of Cl− residing on the 4d site and S2− on the 4a site. By understanding the limitations of ion mobility across a range of length scales, one can target methods to produce solid-state argyrodite electrolytes with higher ionic conductivities.
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Aug 2025
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[36397]
Abstract: The rapidly increasing demand for Li-ion batteries motivates the search for low-cost cathode materials free of critical metals, and with a high energy density and stable cycling performance. Disordered rocksalt oxide (DRX) cathodes derived from abundant metals are particularly promising as they can achieve higher energy densities than commercial, Ni- and/or Co-containing cathodes. However, their further development is hindered by the requirement for a redox-inactive "d0" transition metal to stabilize the disordered structure, and particle nanosizing to achieve appreciable capacity, limiting their energy density and cycle life. We report a new class of d0-free DRX cathodes realized through synthetic control of atomic disorder. Impressively, the removal of d0 species enables a micrometer-sized manganese-based DRX cathode to achieve a high capacity (220 mAh g-1) while extending its cycle life by more than 3x. The discovery of d0-free DRX opens a large, unexplored compositional space and represents a significant step toward the commercialization of inexpensive and Earth-abundant Li-ion cathodes.
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Aug 2025
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B18-Core EXAFS
E02-JEM ARM 300CF
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Diamond Proposal Number(s):
[34632]
Open Access
Abstract: Conventional catalytic CO2 reduction into value-added products often encounters challenges such as high energy barriers and complex operational setups. Here, we introduce a sonocatalysis approach to CO2 reduction in water under ambient conditions. In an acoustic cavitation-induced high-energy local environment, the Cu nanoparticles incorporated on the ZnAl-layered double oxide create a favorable energy barrier for CO2 reduction in water, a CO production rate of 23.8 μmolCO g−1 h−1 with over 85% selectivity was achieved by ultrasonic irradiation of a CO2-saturated aqueous solution at room temperature. Furthermore, more acoustic cavitation was produced with 5% CO2 in argon dissolved in water, resulting in a higher CO productivity of 252.7 μmolCO g−1 h−1, 11 times larger than pure CO2. Hydrogen production also increased with acoustic cavitation, creating a syngas mixture with a CO to H2 ratio of 1.2 to 2.2. This approach produces a high sonochemical efficiency of 211.1 μmol kJ−1 g−1 L−1 for the ultrasound-driven fuel production from CO2 and water. These results highlight the use of cavitation to provide an alternative approach to CO2 conversion.
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May 2025
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I13-2-Diamond Manchester Imaging
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Mengzheng
Ouyang
,
Zhenyu
Guo
,
Luis E.
Salinas-Farran
,
Siyu
Zhao
,
Mengnan
Wang
,
Feiran
Li
,
Yan
Zhao
,
Kaitian
Zheng
,
Hao
Zhang
,
Guangdong
Li
,
Xinhua
Liu
,
Shichun
Yang
,
Fei
Xie
,
Paul
Shearing
,
Maria-Magdalena
Titirici
,
Nigel
Brandon
Diamond Proposal Number(s):
[34782]
Open Access
Abstract: Sodium-ion batteries (SIBs) are cost-effective alternatives to lithium-ion batteries (LIBs), but their low energy density remains a challenge. Current electrode designs fail to simultaneously achieve high areal loading, high active content, and superior performance. In response, this work introduces an ideal electrode structure, featuring a continuous conductive network with active particles securely trapped in the absence of binder, fabricated using a universal technique that combines electrospinning and electrospraying (co-ESP). We found that the particle size must be larger than the network's pores for optimised performance, an aspect overlooked in previous research. The free-standing co-ESP Na2V3(PO4)3 (NVP) cathodes demonstrated state-of-the-art 296 mg cm-2 areal loading with 97.5 wt.% active content, as well as remarkable rate-performance and cycling stability. Co-ESP full cells showed uncompromised energy and power densities (231.6 Wh kg-1/7152.6 W kg-1), leading among reported SIBs with industry-relevant areal loadings. The structural merit is analysed using multi-scale X-ray computed tomography, providing valuable design insights. Finally, the superior performance is validated in the pouch cells, highlighting the electrode’s scalability and potential for commercial application.
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May 2025
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I11-High Resolution Powder Diffraction
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Zhengyan
Lun
,
Alice J.
Merryweather
,
Amoghavarsha
Mahadevegowda
,
Shrinidhi S.
Pandurangi
,
Chao
Xu
,
Simon
Fairclough
,
Vikram
Deshpande
,
Norman A.
Fleck
,
Caterina
Ducati
,
Christoph
Schnedermann
,
Akshay
Rao
,
Clare P.
Grey
Open Access
Abstract: Extensive worldwide efforts have been made to understand the degradation behavior of layered Ni-rich LiNixMnyCo(1−x−y)O2 (NMC) cathodes. The majority of studies carried out to date have focused on thermodynamic perspectives and are conducted ex situ; operando investigations on aged materials, especially those that can resolve dynamic information in a single-particle level remain sparse, preventing the development of long-term stable NMCs. Here, we directly visualize the real-time Li-ion transport kinetics of aged Ni-rich single-crystal NMC under operando conditions and at single-particle level using a recently developed optical microscopy technique. For both fresh and aged particles, we identify Li-ion concentration gradients developing during the early stages of delithiation – resulting in a Li-rich core and Li-poor surface – as observed previously and attributed to low Li-ion diffusivity at high Li-occupancies. Critically, in contrast to fresh particles, the Li-ion gradients in aged particles become markedly asymmetric, with the Li-rich core shifted away from the center of mass of the particle. Using ex situ transmission electron microscopy, we show that cell aging produces an uneven build-up of a surface rocksalt layer. Supported by finite-element modelling, we attribute the asymmetric delithiation behavior of the aged particles to this uneven rocksalt layer, which impedes the Li-ion flux heterogeneously at the particle surface. Our results demonstrate a new mechanism that contributes to the capacity and rate degradation of Ni-rich cathodes, highlighting the importance of controlling the build-up of detrimental interfacial layers in cathodes and providing a rational for improving the long-term stability and rate capabilities of Ni-rich NMC cathodes.
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Mar 2025
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[30759]
Open Access
Abstract: Metal-oxide coatings are a favoured strategy for mitigating surface degradation problems in state-of-the-art lithium-ion battery Ni-rich layered positive electrode materials. Despite their extensive use, a full, fundamental understanding of the role of coatings in reducing degradation and extending cycling lifetimes is currently lacking. In this work, the interactions between an atomic layer deposited (ALD) alumina coating on polycrystalline LiNi0.8Mn0.1Co0.1O2 (NMC811) and a carbonate-based battery electrolyte are studied. Solid-state nuclear magnetic resonance (ssNMR) heteronuclear experiments show that the Al2O3 coating transforms by reacting with electrolyte species present before and during electrochemical cycling, scavenging protic and acidic species. Density-functional theory calculations highlight the additional chemical effect of the coating in locally stabilising the structure of the NMC811, limiting oxidation of the oxygen atoms coordinated to both Al and Ni, thereby limiting the surface reconstruction process and improving the electrochemical performance. Improved NMC811 surface stability is confirmed by monitoring gaseous degradation species by online electrochemical mass-spectrometry and via X-ray spectroscopic analysis of the electrochemically aged samples to examine changes in Ni and O oxidation state and local structure. The combination of this experimental and theoretical analysis suggests that Al2O3 coatings have a dual role: as a protective barrier against attack from chemical species in the electrolyte, and as an artificial passivating layer hindering oxygen loss and surface phase transformations. This holistic approach, which provides a fundamental understanding of how the surface stability is improved by the coating, will aid the design of the state-of-the-art and future positive electrode materials.
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Jan 2025
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B18-Core EXAFS
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Diamond Proposal Number(s):
[36104]
Abstract: The sulfion oxidation reaction (SOR) assisted seawater electrolysis has been proposed to be a potentially cost-effective approach to hydrogen production because SOR happens at an anodic potential significantly lower than that of the energy-demanding oxygen evolution reaction (OER). However, the key to unleash full potential of SOR for practical seawater electrolysis is to develop highly efficient and stable electrocatalysts able to sustain in harsh seawater environment at high current densities. Herein, we report the fabrication of nickel foam supported nickel telluride nanorod arrays covered conformally with an electrodeposited amorphous nickel molybdenum layer (NiTe@NiMo/NF), which exhibit outstanding SOR performance, capable of delivering 500 mA cm−2 at only 0.55 V vs. reversible hydrogen electrode (RHE) and operating at 500 mA cm−2 for 100 hours without degradation, in both simulated and natural seawater. Our comprehensive experimental and theoretical studies reveal that the NiTe@NiMo/NF electrode undergoes a dynamic reconstruction process, and the in-situ generated [MoO4]2− moieties can modulate and stabilize the catalytically active NiTe/NiOOH, improving the SOR activity and stability. Consequently, the asymmetric membrane electrode assembly comprising NiTe@NiMo/NF as the anode can deliver a current density as large as 5.0 A cm−2 at 1.33 V in alkaline natural seawater at 70 °C and operate at 1.0 A cm−2 below 1.0 V for 334 hours, holding great potential for energy-saving and cost-competitive hydrogen production from seawater.
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Dec 2024
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I21-Resonant Inelastic X-ray Scattering (RIXS)
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Gukhyun
Lim
,
Min Kyung
Cho
,
Jaewon
Choi
,
Ke-Jin
Zhou
,
Dongki
Shin
,
Seungyun
Jeon
,
Minhyung
Kwon
,
A-Re
Jeon
,
Jinkwan
Choi
,
Seok Su
Sohn
,
Minah
Lee
,
Jihyun
Hong
Abstract: Exploiting oxygen anion redox in Li-/Mn-rich layered oxides (LMR-NMCs) offers the highest capacity among cathode materials for Li-ion batteries (LIBs). However, its long-term utilization is challenging due to continuous voltage and capacity decay caused by irreversible phase transitions involving cation disordering and oxygen release. While extensive studies have revealed the thermodynamic origin of cation disordering, the mechanisms of oxygen loss and consequent lattice densification remain elusive. Moreover, mixed spinel-rocksalt nanodomains formed after cycling complicate the degradation mechanism. Herein, we reveal a strong correlation between phase transition pathways and oxygen stability at the particle surface in LMR-NMCs through a comparative study using electrolyte modification. By tailoring surface reconstruction pathways, we control the overall phase and electrochemistry evolution mechanisms. Removing polar ethylene carbonate from the electrolyte significantly suppresses irreversible oxygen loss at the cathode–electrolyte interface, preferentially promoting the in situ layered-to-spinel phase transition while avoiding typical rocksalt phase formation. The in situ formed spinel-stabilized surface enhances charge transfer kinetics through three-dimensional ion channels, maintaining reversible Ni, Mn, and O redox capability over 700 cycles, as revealed by electron microscopy, X-ray absorption spectroscopy, and resonant inelastic X-ray scattering. Deep delithiation and lithiation enabled by the surface spinel phase accelerate the bulk layered-to-spinel phase transition, inducing thermodynamic voltage fade without capacity loss. Conversely, conventional electrolytes induce layered-to-rocksalt surface reconstruction, impeding charge transfer reactions, which causes simultaneous capacity and (apparent) voltage fades. Our work decouples thermodynamic and kinetic aspects of voltage decay in LMR-NMCs, establishing the correlation between surface reconstruction, bulk phase transition, and the electrochemistry of high-capacity cathodes that exploit cation and anion redox couples. This study highlights the significance of electrochemical interface stabilization for advancing Mn-rich cathode chemistries in future LIBs.
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Nov 2024
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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
I10-Beamline for Advanced Dichroism - scattering
I20-Scanning-X-ray spectroscopy (XAS/XES)
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Lijin
An
,
Ruomu
Zhang
,
Prvanin N.
Didwal
,
Michael W.
Fraser
,
Leanne A. H.
Jones
,
Conor M. E.
Phelan
,
Namrata
Ramesh
,
Grant
Harris
,
Robert S.
Weatherup
,
Jack E. N.
Swallow
,
Peixi
Cong
,
Andrey
Poletayev
,
Erik
Bjorklund
,
Christophe J.
Sahle
,
Pilar
Ferrer
,
David C.
Grinter
,
Peter
Bencok
,
Shusaku
Hayama
,
Saiful
Islam
,
Robert
House
,
Peter D.
Nellist
,
Robert J.
Green
,
Rebecca J.
Nicholls
Diamond Proposal Number(s):
[33283, 33062, 32010]
Open Access
Abstract: Ni-rich layered oxide cathodes can deliver higher energy density batteries, but uncertainties remain over their charge compensation mechanisms and the degradation processes that limit cycle life. Trapped molecular O2 has been identified within LiNiO2 at high states of charge, as seen for Li-rich cathodes where excess capacity is associated with reversible O-redox. Here we show that bulk redox in LiNiO2 occurs by Ni-O rehybridization, lowering the electron density on O sites, but importantly without the involvement of molecular O2. Instead, trapped O2 is related to degradation at surfaces in contact with the electrolyte, and is accompanied by Ni reduction. O2 is removed on discharge, but excess Ni2+ persists forming a reduced surface layer, associated with impeded Li transport. This implicates the instability of delithiated LiNiO2 in contact with the electrolyte in surface degradation through O2 formation and Ni reduction, highlighting the importance of surface stabilisation strategies in suppressing LNO degradation.
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Sep 2024
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