I11-High Resolution Powder Diffraction
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Jungwoo
Lim
,
Manel
Sonni
,
Luke M.
Daniels
,
Mounib
Bahri
,
Marco
Zanella
,
Ruiyong
Chen
,
Zhao
Li
,
Alex R.
Neale
,
Hongjun
Niu
,
Nigel D.
Browning
,
Matthew S.
Dyer
,
John B.
Claridge
,
Laurence J.
Hardwick
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[31578]
Open Access
Abstract: LiNiO2 positive electrode materials for lithium-ion batteries have experienced a revival of interest due to increasing technological energy demands. Herein a specific Ti4+ substitution is targeted into LiNiO2 to access new compositions by synthesizing the LiNi1–xTi3x/4O2 solid solution with the aim of retaining Ni3+. Compositions in the range 0.025 ≤ x ≤ 0.2 form nanocomposites of compositionally homogeneous ordered R
m and disordered Fm
m rock salt domains as observed via X-ray and neutron diffraction, and STEM. The disordered rock salt domains stabilize the ordered structure to provide excellent structural reversibility via the formation of coherent interfaces during cycling and enable deep delithiation using a constant voltage charging step without structural degradation. The detrimental structural phase transitions associated with the poor cyclability of LiNiO2 are suppressed to yield a low strain positive electrode material with high capacity retention that offers high-rate capability even under increased cell electrode mass loadings. The composition x = 0.075 (LiNi0.925Ti0.05625O2) affords a 93% capacity retention after 100 cycles (100 mA g−1) and demonstrates high reversible capacities of 125 mAh g−1 even under rates of 3200 mA g−1. LiNi0.925Ti0.05625O2 exhibits exceptional performance at electrode mass loadings (13.6 mg cm−2) comparable to those required for commercial cell applications.
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Jul 2025
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Matthew A.
Wright
,
Jungwoo
Lim
,
Raul A.
Pacheco Muino
,
Anna E.
Krowitz
,
Cara J.
Hawkins
,
Mounib
Bahri
,
Luke M.
Daniels
,
Ruiyong
Chen
,
Luciana
Gomes Chagas
,
James
Cookson
,
Paul
Collier
,
Alan V.
Chadwick
,
Nigel D.
Browning
,
John B.
Claridge
,
Laurence J.
Hardwick
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[31578]
Open Access
Abstract: V2Se9 displays facile electrochemical insertion of up to 1.6 Mg2+ per unit formula with fast diffusion (coefficients of 10-10 – 10-12 cm2 s-1) surpassing best-in-class materials like Mo6S8. Detailed structural characterization of synchrotron X-ray diffraction data with ab initio Maximum Entropy Method analysis reveals Mg2+ insertion onto octahedral sites within the large vdW space between [V4Se18]∞ chains. Fast rate performance is attributed to low structural perturbation and low diffusion barriers, calculated by bond valence pathway analysis, resulting from the low charge-per-size of anionic selenium. X-ray photoelectron spectroscopy and X-ray absorption spectroscopy reveal that reversible insertion of Mg2+ is facilitated by V5+/V3+ redox. V2Se9 demonstrates that selenides, despite their larger molecular weight, offer potential as fast rate positive electrode materials for magnesium batteries over well-explored oxides and sulfides.
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Oct 2024
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I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
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Guopeng
Han
,
Luke M.
Daniels
,
Andrij
Vasylenko
,
Kate A.
Morrison
,
Lucia
Corti
,
Chris M.
Collins
,
Hongjun
Niu
,
Ruiyong
Chen
,
Craig M.
Robertson
,
Frédéric
Blanc
,
Matthew S.
Dyer
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[31578, 36629]
Open Access
Abstract: Ge4+ substitution into the recently discovered superionic conductor Li7Si2S7I is demonstrated by synthesis of Li7Si2–xGexS7I, where x ≤ 1.2. The anion packing and tetrahedral silicon location of Li7Si2S7I are retained upon substitution. Single crystal X-ray diffraction shows that substitution of larger Ge4+ for Si4+ expands the unit cell volume and further increases Li+ site disorder, such that Li7Si0.88Ge1.12S7I has one Li+ site more (sixteen in total) than Li7Si2S7I. The ionic conductivity of Li7Si0.8Ge1.2S7I (x = 1.2) at 303 K is 1.02(3) × 10–2 S cm–1 with low activation energies for Li+ transport demonstrated over a wide temperature range by AC impedance and 7Li NMR spectroscopy. All sixteen Li+ sites remain occupied to temperatures as low as 30 K in Li7Si0.88Ge1.12S7I as a result of the structural expansion. This differs from Li7Si2S7I, where the partial Li+ site ordering observed below room temperature reduces the ionic conductivity. The suppression of Li+ site depopulation by Ge4+ substitution retains the high mobility to temperatures as low as 200 K, yielding low temperature performance comparable with state-of-the-art Li ion conducting materials.
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Jun 2024
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
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Matthew A.
Wright
,
T. Wesley
Surta
,
Jae A.
Evans
,
Jungwoo
Lim
,
Hongil
Jo
,
Cara J.
Hawkins
,
Mounib
Bahri
,
Luke M.
Daniels
,
Ruiyong
Chen
,
Marco
Zanella
,
Luciana G.
Chagas
,
James
Cookson
,
Paul
Collier
,
Giannantonio
Cibin
,
Alan V.
Chadwick
,
Matthew S.
Dyer
,
Nigel D.
Browning
,
John B.
Claridge
,
Laurence J.
Hardwick
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[31578]
Open Access
Abstract: Magnesium batteries attract interest as alternative energy-storage devices because of elemental abundance and potential for high energy density. Development is limited by the absence of suitable cathodes, associated with poor diffusion kinetics resulting from strong interactions between Mg2+ and the host structure. V2PS10 is reported as a positive electrode material for rechargeable magnesium batteries. Cyclable capacity of 100 mAh g-1 is achieved with fast Mg2+ diffusion of 7.2[[EQUATION]]10-11-4[[EQUATION]]10-14 cm2s-1. The fast insertion mechanism results from combined cationic redox on the V site and anionic redox on the (S2)2- site; enabled by reversible cleavage of S–S bonds, identified by X-ray photoelectron and X-ray absorption spectroscopy. Detailed structural characterisation with maximum entropy method analysis, supported by density functional theory calculations and projected density of states analysis, reveals that the sulphur species involved in anion redox are not connected to the transition metal centres, spatially separating the two redox processes. This facilitates fast and reversible Mg insertion in which the nature of the redox process depends on the cation insertion site, creating a synergy between the occupancy of specific Mg sites and the location of the electrons transferred.
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Mar 2024
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I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
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Guopeng
Han
,
Andrij
Vasylenko
,
Luke M.
Daniels
,
Chris M.
Collins
,
Lucia
Corti
,
Ruiyong
Chen
,
Hongjun
Niu
,
Troy D.
Manning
,
Dmytro
Antypov
,
Matthew S.
Dyer
,
Jungwoo
Lim
,
Marco
Zanella
,
Manel
Sonni
,
Mounib
Bahri
,
Hongil
Jo
,
Yun
Dang
,
Craig M.
Robertson
,
Frédéric
Blanc
,
Laurence J.
Hardwick
,
Nigel D.
Browning
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[30461, 31578]
Abstract: Fast cation transport in solids underpins energy storage. Materials design has focused on structures that can define transport pathways with minimal cation coordination change, restricting attention to a small part of chemical space. Motivated by the greater structural diversity of binary intermetallics than that of the metallic elements, we used two anions to build a pathway for three-dimensional superionic lithium ion conductivity that exploits multiple cation coordination environments. Li7Si2S7I is a pure lithium ion conductor created by an ordering of sulphide and iodide that combines elements of hexagonal and cubic close-packing analogously to the structure of NiZr. The resulting diverse network of lithium positions with distinct geometries and anion coordination chemistries affords low barriers to transport, opening a large structural space for high cation conductivity.
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Feb 2024
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I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
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Alexandra
Morscher
,
Benjamin B.
Duff
,
Guopeng
Han
,
Luke M.
Daniels
,
Yun
Dang
,
Marco
Zanella
,
Manel
Sonni
,
Ahmad
Malik
,
Matthew S.
Dyer
,
Ruiyong
Chen
,
Frédéric
Blanc
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[23666, 21726]
Open Access
Abstract: Argyrodite is a key structure type for ion-transporting materials. Oxide argyrodites are largely unexplored despite sulfide argyrodites being a leading family of solid-state lithium-ion conductors, in which the control of lithium distribution over a wide range of available sites strongly influences the conductivity. We present a new cubic Li-rich (>6 Li+ per formula unit) oxide argyrodite Li7SiO5Cl that crystallizes with an ordered cubic (P213) structure at room temperature, undergoing a transition at 473 K to a Li+ site disordered F4̅3m structure, consistent with the symmetry adopted by superionic sulfide argyrodites. Four different Li+ sites are occupied in Li7SiO5Cl (T5, T5a, T3, and T4), the combination of which is previously unreported for Li-containing argyrodites. The disordered F4̅3m structure is stabilized to room temperature via substitution of Si4+ with P5+ in Li6+xP1–xSixO5Cl (0.3 < x < 0.85) solid solution. The resulting delocalization of Li+ sites leads to a maximum ionic conductivity of 1.82(1) × 10–6 S cm–1 at x = 0.75, which is 3 orders of magnitude higher than the conductivities reported previously for oxide argyrodites. The variation of ionic conductivity with composition in Li6+xP1–xSixO5Cl is directly connected to structural changes occurring within the Li+ sublattice. These materials present superior atmospheric stability over analogous sulfide argyrodites and are stable against Li metal. The ability to control the ionic conductivity through structure and composition emphasizes the advances that can be made with further research in the open field of oxide argyrodites.
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Nov 2022
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I11-High Resolution Powder Diffraction
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Bernhard T.
Leube
,
Christopher M.
Collins
,
Luke M.
Daniels
,
Benjamin B.
Duff
,
Yun
Dang
,
Ruiyong
Chen
,
Michael W.
Gaultois
,
Troy D.
Manning
,
Frédéric
Blanc
,
Matthew S.
Dyer
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[17193]
Open Access
Abstract: A tetragonal argyrodite with >7 mobile cations, Li7Zn0.5SiS6, is experimentally realized for the first time through solid state synthesis and exploration of the Li–Zn–Si–S phase diagram. The crystal structure of Li7Zn0.5SiS6 was solved ab initio from high-resolution X-ray and neutron powder diffraction data and supported by solid-state NMR. Li7Zn0.5SiS6 adopts a tetragonal I4 structure at room temperature with ordered Li and Zn positions and undergoes a transition above 411.1 K to a higher symmetry disordered F43m structure more typical of Li-containing argyrodites. Simultaneous occupation of four types of Li site (T5, T5a, T2, T4) at high temperature and five types of Li site (T5, T2, T4, T1, and a new trigonal planar T2a position) at room temperature is observed. This combination of sites forms interconnected Li pathways driven by the incorporation of Zn2+ into the Li sublattice and enables a range of possible jump processes. Zn2+ occupies the 48h T5 site in the high-temperature F43m structure, and a unique ordering pattern emerges in which only a subset of these T5 sites are occupied at room temperature in I4 Li7Zn0.5SiS6. The ionic conductivity, examined via AC impedance spectroscopy and VT-NMR, is 1.0(2) × 10–7 S cm–1 at room temperature and 4.3(4) × 10–4 S cm–1 at 503 K. The transition between the ordered I4 and disordered F43m structures is associated with a dramatic decrease in activation energy to 0.34(1) eV above 411 K. The incorporation of a small amount of Zn2+ exercises dramatic control of Li order in Li7Zn0.5SiS6 yielding a previously unseen distribution of Li sites, expanding our understanding of structure–property relationships in argyrodite materials.
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Apr 2022
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I11-High Resolution Powder Diffraction
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Dingyue
Hu
,
Karl
Dawson
,
Marco
Zanella
,
Troy D.
Manning
,
Luke M.
Daniels
,
Nigel D.
Browning
,
B. Layla
Mehdi
,
Yaobin
Xu
,
Houari
Amari
,
J. Felix
Shin
,
Michael J.
Pitcher
,
Ruiyong
Chen
,
Hongjun
Niu
,
Bowen
Liu
,
Matthew
Bilton
,
Junyoung
Kim
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[23666]
Open Access
Abstract: Performance durability is one of the essential requirements for solid oxide fuel cell materials operating in the intermediate temperature range (500–700 °C). The trade-off between desirable catalytic activity and long-term stability challenges the development and commercialization of electrode materials. Here an oxygen cathode material, Ba0.5Sr0.5(Co0.7Fe0.3)0.69−xMgxW0.31O3−δ (BSCFW-xMg), that exhibits excellent electrocatalytic performance through the addition of an optimized amount of Mg to the self-assembled nanocomposite Ba0.5Sr0.5(Co0.7Fe0.3)0.69W0.31O3−δ (BSCFW) by simple solid-state reaction is reported. Distinct from the bulk and surface approaches to introduce vacancies and defects in materials design, here the Mg2+ ions concentrate at the single perovskite/double perovskite interface of BSCFW with dislocations and Mg2+-rich nanolayers, resulting in stressed and compositionally inhomogeneous interface regions. The interfacial chemistry within these nanocomposites provides an additional degree of freedom to enable performance optimization over single phase materials and promotes the durability of alkaline-earth based fuel cell materials.
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Mar 2022
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I11-High Resolution Powder Diffraction
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Open Access
Abstract: Protonic ceramic fuel cells (PCFCs) are attractive energy conversion devices for intermediate-temperature operation (400-600 °C), however widespread application of PCFCs relies on the development of new high-performance electrode materials. Here we report the electrochemical and protonic properties of a self-assembled nanocomposite, Ba0.5Sr0.5(Co0.7Fe0.3)0.6875W0.3125O3−δ (BSCFW) consisting of a disordered single perovskite and an ordered double perovskite phase, as a PCFC cathode material. BSCFW shows thermodynamic and kinetic protonic behaviour conducive to PCFC application with favourable proton defect formation enthalpy (ΔH = -35±7 kJ mol–1) comparable to existing proton conducting electrolyte materials. BSCFW presents an excellent polarization resistance (Rp) of 0.172(2) Ω cm2 at 600 °C and a high power density of 582(1) mW cm–2 through singlecell measurement, which is comparable performance to current state-of-the-art cathode materials. BSCFW exhibits good chemical and thermal stability against BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) electrolyte with a low Rp degradation rate of 1.0(1) × 10-6 Ω cm2 min-1. These performance and stability figures represent an advance beyond those of Ba0.5Sr0.5Co0.7Fe0.3O3−δ (BSCF), which is unstable under the same conditions and is incompatible with the electrolyte material. Our comprehensive characterization of the protonic properties of BSCFW, whose performance and stability are ensured via the interplay of the single and double perovskite phases, provides fundamental understanding that will inform the future design of high-performance PCFC cathodes.
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Dec 2021
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I19-Small Molecule Single Crystal Diffraction
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Guopeng
Han
,
Andrij
Vasylenko
,
Alex R.
Neale
,
Benjamin B.
Duff
,
Ruiyong
Chen
,
Matthew S.
Dyer
,
Yun
Dang
,
Luke
Daniels
,
Marco
Zanella
,
Craig
Robertson
,
Laurence J.
Kershaw Cook
,
Anna-Lena
Hansen
,
Michael
Knapp
,
Laurence J.
Hardwick
,
Frédéric
Blanc
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[21726]
Open Access
Abstract: Extended anionic frameworks based on condensation of polyhedral main group non-metal anions offer a wide range of structure types. Despite the widespread chemistry and earth abundance of phosphates and silicates, there are no reports of extended ultraphosphate anions with lithium. We describe the lithium ultraphosphates Li3P5O14 and Li4P6O17 based on extended layers and chains of phosphate, respectively. Li3P5O14 presents a complex structure containing infinite ultraphosphate layers with 12-membered rings that are stacked alternately with lithium polyhedral layers. Two distinct vacant tetrahedral sites were identified at the end of two distinct finite Li6O1626– chains. Li4P6O17 features a new type of loop-branched chain defined by six PO43– tetrahedra. The ionic conductivities and electrochemical properties of Li3P5O14 were examined by impedance spectroscopy combined with DC polarization, NMR spectroscopy, and galvanostatic plating/stripping measurements. The structure of Li3P5O14 enables three-dimensional lithium migration that affords the highest ionic conductivity (8.5(5) × 10–7 S cm–1 at room temperature for bulk), comparable to that of commercialized LiPON glass thin film electrolytes, and lowest activation energy (0.43(7) eV) among all reported ternary Li–P–O phases. Both new lithium ultraphosphates are predicted to have high thermodynamic stability against oxidation, especially Li3P5O14, which is predicted to be stable to 4.8 V, significantly higher than that of LiPON and other solid electrolytes. The condensed phosphate units defining these ultraphosphate structures offer a new route to optimize the interplay of conductivity and electrochemical stability required, for example, in cathode coatings for lithium ion batteries.
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Oct 2021
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