I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
|
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.
|
Feb 2024
|
|
I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
|
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.
|
Nov 2022
|
|
I11-High Resolution Powder Diffraction
|
Diamond Proposal Number(s):
[23666]
Open Access
Abstract: The synthesis, structure, and properties of the three-anion superlattice materials Bi4O4SeBr2 and Bi6O6Se2Cl2 are reported. These materials crystallise in structures that form part of a homologous series of compounds comprised of stackings of BiOCl- and Bi2O2Se-like units. Bi4O4SeBr2 is analogous to Bi4O4Se2Cl2, whereas Bi6O6Se2Cl2 contains an additional Bi2O2Se layer that produces off-centred anions. The band gaps of both materials are indirect, with Eg = 1.15(5) eV, and the materials behave as doped semiconductors with very low thermal conductivities. These materials expand the synthetic scope of multiple anion superlattice materials and, with optimisation, may also be platforms for future thermoelectric materials.
|
May 2022
|
|
I11-High Resolution Powder Diffraction
|
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.
|
Mar 2022
|
|
I11-High Resolution Powder Diffraction
|
Harry C.
Sansom
,
Leonardo R. V.
Buizza
,
Marco
Zanella
,
James T.
Gibbon
,
Michael
Pitcher
,
Matthew S.
Dyer
,
Troy D.
Manning
,
Vinod R.
Dhanak
,
Laura M.
Herz
,
Henry J.
Snaith
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Open Access
Abstract: A newly reported compound, CuAgBiI5, is synthesized as powder, crystals, and thin films. The structure consists of a 3D octahedral Ag+/Bi3+ network as in spinel, but occupancy of the tetrahedral interstitials by Cu+ differs from those in spinel. The 3D octahedral network of CuAgBiI5 allows us to identify a relationship between octahedral site occupancy (composition) and octahedral motif (structure) across the whole CuI–AgI–BiI3 phase field, giving the ability to chemically control structural dimensionality. To investigate composition–structure–property relationships, we compare the basic optoelectronic properties of CuAgBiI5 with those of Cu2AgBiI6 (which has a 2D octahedral network) and reveal a surprisingly low sensitivity to the dimensionality of the octahedral network. The absorption onset of CuAgBiI5 (2.02 eV) barely changes compared with that of Cu2AgBiI6 (2.06 eV) indicating no obvious signs of an increase in charge confinement. Such behavior contrasts with that for lead halide perovskites which show clear confinement effects upon lowering dimensionality of the octahedral network from 3D to 2D. Changes in photoluminescence spectra and lifetimes between the two compounds mostly derive from the difference in extrinsic defect densities rather than intrinsic effects. While both materials show good stability, bulk CuAgBiI5 powder samples are found to be more sensitive to degradation under solar irradiation compared to Cu2AgBiI6.
|
Nov 2021
|
|
I11-High Resolution Powder Diffraction
|
Open Access
Abstract: Mixed anion materials and anion doping are very promising strategies to improve solid-state electrolyte properties by enabling an optimized balance between good electrochemical stability and high ionic conductivity. In this work, we present the discovery of a novel lithium aluminum sulfide–chloride phase, obtained by substitution of chloride for sulfur in Li3AlS3 and Li5AlS4 materials. The structure is strongly affected by the presence of chloride anions on the sulfur site, as the substitution was shown to be directly responsible for the stabilization of a higher symmetry phase presenting a large degree of cationic site disorder, as well as disordered octahedral lithium vacancies. The effect of disorder on the lithium conductivity properties was assessed by a combined experimental–theoretical approach. In particular, the conductivity is increased by a factor 103 compared to the pure sulfide phase. Although it remains moderate (10–6 S·cm–1), ab initio molecular dynamics and maximum entropy (applied to neutron diffraction data) methods show that disorder leads to a 3D diffusion pathway, where Li atoms move thanks to a concerted mechanism. An understanding of the structure–property relationships is developed to determine the limiting factor governing lithium ion conductivity. This analysis, added to the strong step forward obtained in the determination of the dimensionality of diffusion, paves the way for accessing even higher conductivity in materials comprising an hcp anion arrangement.
|
Nov 2021
|
|
I19-Small Molecule Single Crystal Diffraction
|
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.
|
Oct 2021
|
|
I11-High Resolution Powder Diffraction
|
Andrij
Vasylenko
,
Jacinthe
Gamon
,
Benjamin B.
Duff
,
Vladimir V.
Gusev
,
Luke M.
Daniels
,
Marco
Zanella
,
J. Felix
Shin
,
Paul M.
Sharp
,
Alexandra
Morscher
,
Ruiyong
Chen
,
Alex R.
Neale
,
Laurence J.
Hardwick
,
John B.
Claridge
,
Frédéric
Blanc
,
Michael W.
Gaultois
,
Matthew S.
Dyer
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[23666]
Open Access
Abstract: The selection of the elements to combine delimits the possible outcomes of synthetic chemistry because it determines the range of compositions and structures, and thus properties, that can arise. For example, in the solid state, the elemental components of a phase field will determine the likelihood of finding a new crystalline material. Researchers make these choices based on their understanding of chemical structure and bonding. Extensive data are available on those element combinations that produce synthetically isolable materials, but it is difficult to assimilate the scale of this information to guide selection from the diversity of potential new chemistries. Here, we show that unsupervised machine learning captures the complex patterns of similarity between element combinations that afford reported crystalline inorganic materials. This model guides prioritisation of quaternary phase fields containing two anions for synthetic exploration to identify lithium solid electrolytes in a collaborative workflow that leads to the discovery of Li3.3SnS3.3Cl0.7. The interstitial site occupancy combination in this defect stuffed wurtzite enables a low-barrier ion transport pathway in hexagonal close-packing.
|
Sep 2021
|
|
I11-High Resolution Powder Diffraction
|
Christopher M.
Collins
,
Luke M.
Daniels
,
Quinn
Gibson
,
Michael W.
Gaultois
,
Michael
Moran
,
Richard
Feetham
,
Michael J.
Pitcher
,
Matthew S
Dyer
,
Charlene
Delacotte
,
Marco
Zanella
,
Claire A.
Murray
,
Gyorgyi
Glodan
,
Olivier
Perez
,
Denis
Pelloquin
,
Troy D.
Manning
,
Jonathan
Alaria
,
George R.
Darling
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Open Access
Abstract: We report the aperiodic titanate Ba 10 Y 6 Ti 4 O 27 with a room temperature thermal conductivity that equals the lowest reported for an oxide. The structure is characterised by discontinuous occupancy modulation of each of the sites, and can be considered as a quasicrystal. The resulting localisation of lattice vibrations suppresses phonon transport of heat. This new lead material for low thermal conductivity oxides is metastable and located within a quaternary phase field that has been previously explored – its isolation thus requires a precisely‐defined synthetic protocol. The necessary narrowing of the search space for experimental investigation is achieved by evaluation of titanate crystal chemistry, prediction of unexplored structural motifs that will favour synthetically accessible new compositions and assessment of their properties with machine learning models.
|
May 2021
|
|
I11-High Resolution Powder Diffraction
|
Luis
Alvarado Rupflin
,
Hendrik
Van Rensburg
,
Marco
Zanella
,
Elliot J.
Carrington
,
Rebecca
Vismara
,
Alexios
Grigoropoulos
,
Troy D.
Manning
,
John B.
Claridge
,
Alexandros P.
Katsoulidis
,
Robert P.
Tooze
,
Matthew J.
Rosseinsky
Abstract: A proxy-based high-throughput experimental approach was used to explore the stability and activity of Co-based Fischer-Tropsch Synthesis catalysts with different promoters on a variety of supports. The protocol is based on XRD estimation of the active phase polymorph, particle size and ratio of crystalline phases of Co to support. Sequential sample libraries enabled exploration of four Co loadings with five different promoters on six support materials. Catalysts stable to aging in syngas, i.e. displaying minimal change of particle size or active phase concentration, were evaluated under industrial conditions. This procedure identified SiC as a support that confers catalyst stability and that a combination of Ru and Hf promotes the stabilisation of hcp Co. Unsupported bulk samples of Co with appropriate amounts of Ru and Hf revealed that the formation of hcp Co is independent of the support. The hcp Co-containing catalyst afforded the highest catalytic activity and C5+ selectivity amongst the samples tested in this study, confirming the effectiveness of the proxy-based high-throughput method.
|
Mar 2021
|
|
