Materials

Research in the section is focussed across the spectrum of materials chemistry from inorganic materials to organic, inorganic/organic hybrid materials.

We have interests that span the areas of material design, synthesis and characterisation that are focussed on applications as diverse as battery and hydrogen/ammonia storage/fuel cell materials, porous solids for catalysis, gas storage, nuclear waste remediation, nanoscience. Alongside these activities, we have a significant focus on recycling and sustainability – in particular in the areas of batteries.

We make extensive use of synchrotron and neutron diffraction techniques and have strong links to these central facilities as well as collaborations across the University in areas that include Materials and Metallurgy, Environmental Science, and Chemical Engineering.

Research section leader

Areas of interest

Lithium- and sodium-ion batteries, recycling, solid-state materials synthesis, mechanochemistry structural characterization, fuel cells.

Representative publication

Representative paper: Under pressure: offering fundamental insight into structural changes on ball milling battery materials

Laura L. Driscoll,  Elizabeth H. Driscoll,  Bo Dong, Farheen N. Sayed,  Jacob N. Wilson,  Christopher A. O’Keefe,  Dominic J. Gardner,  Clare P. Grey,  Phoebe K. Allan,  Adam A. L. Michalchuk  and Peter R. Slater ; Energy and Environmental Science 2023, 16, 5196.

Mechanochemical synthesis of Li ion battery materials is a large growth area for the formation of new systems, such as high capacity disordered rock salt phases. In this work we show the importance of local pressure effects from the milling balls striking the powder, and illustrate the potential to employ ball milling as an approach to achieve high pressure phase transformations.

Research unit members

Areas of interest

Lithium- and sodium-ion batteries, ion-exchangers, electrochemistry, recycling, solid-state materials synthesis, synchrotron-based characterization, in situ studies of functional behaviour.

Representative paper: Correlating Local Structure and Sodium Storage in Hard Carbon Anodes: Insights from Pair Distribution Function Analysis and Solid-State NMR

Joshua M. Stratford, Annette K. Kleppe, Dean S. Keeble, Philip A. , Wright Jerry Barker, Maria-Magdalena Titirici, Phoebe K. Allan*, Clare P. Grey*. Journal of the American Chemical Society, J. Am. Chem. Soc. 2021, 143, 35, 14274–14286.

Hard carbons are the leading candidate anode materials for sodium-ion batteries. However, the sodium-insertion mechanisms remain under debate. Here, employing a novel analysis of operando and ex situ pair distribution function (PDF) analysis of total scattering data, supplemented by information on the local electronic structure provided by operando 23Na solid-state NMR, we identify the local atomic environments of sodium stored within hard carbon and provide a revised mechanism for sodium storage. At higher-voltages consistent with sodium ions stored close to defective areas of the carbon, with electrons localized in the antibonding π*-orbitals of the carbon. Metallic sodium clusters approximately 13–15 Å in diameter are formed in both carbons at lower voltages. These results reveal that local atomic structure has a definitive role in determining storage capacity, and therefore the effect of synthetic conditions on both the local atomic structure and the microstructure should be considered when engineering hard carbons.

Antimony is a promising high-capacity anode material for sodium-ion batteries.  However, many of the (dis)charge products are amorphous, meaning that the way in which sodium is stored in the material is not well understood.  This paper uses solid-state NMR and (X-ray) pair distribution function analysis - methods which are sensitive to the local structure - to shed light upon the amorphous discharge products and hence the reasons for the excellent electrochemical performance of antimony anodes.  

Areas of interest

Critical materials, recycling, endangered elements, hydrogen storage materials, metal-organic frameworks, microporous materials, materials for energy storage and conversion, non-oxide solid electrolytes, zeolites.

Representative paper: Phase-selective recovery and regeneration of end-of-life electric vehicle blended cathodes via selective leaching and direct recycling

Laura L. Driscoll, Abbey Jarvis, Rosie Madge, Elizabeth H. Driscoll, Jaime-Marie Price , Rob Sommerville , Felipe Schnaider Tontini , Mounib Bahri , Milon Miah , B. Layla Mehdi , Emma Kendrick , Nigel D. Browning , Phoebe K. Allan, Paul A. Anderson , Peter R. Slater , Joule 2025, 8, 2735-2744.

A critical component of the drive to deliver net zero economies is the introduction of electric vehicles, which necessitates the need for the development of efficient ways to recycle EV batteries. Neverthelss recycling is challenging, particularly if the feedstock contains a mixture of cathode materials, which leads to a requirement for complex multistep, high waste, separation processes. In this work, we show that ascorbic acid (vitamin C) can selectively leach a Mn rich cathode from a Ni rich cathode, simplyfying the recycling process and allowing more direct recycling approaches to be used.

Areas of interest

Quantum materials, magnetic materials, materials discovery, structure-property relationships, X-ray and neutron scattering, muon spectroscopy

Representative paper: Kitaev interactions through extended superexchange pathways in the j_eff = 1/2 Ru³⁺ honeycomb magnet RuP₃SiO₁₁

Aly H. Abdeldaim, Hlynur Gretarsson, Sarah J. Day, M. Duc Le, Gavin B. G. Stenning, Pascal Manuel, Robin S. Perry, Alexander A. Tsirlin, Gøran J. Nilsen and Lucy Clark Nat. Commun., 2024, 15, 977874.

Quantum spin liquids (QSLs) occur when the magnetic moments in a material act like a liquid, remaining dynamic and disordered even at absolute zero. Their highly entangled nature should give rise to exotic physical phenomena that could have applications in quantum computing, and developments in QSLs may also help in the understanding of high-temperature superconductivity. This paper provides the first experimental proof that anisotropic exchange interactions can survive extended, multi-atom superexchange pathways found in framework materials, opening a new paradigm in the search for the QSL.

Areas of interest

Energy storage, hydrogen storage, solid state chemistry, metal-nitrogen-hydrogen materials, ammonia synthesis and decomposition, ionic conduction, X-ray and neutron powder diffraction, in situ characterisation.

Representative paper: Ammonia decomposition catalysis using non-stoichiometric lithium imide.

JW Makepeace, TJ Wood, HMA Hunter, MO Jones, WIF David, Chemical Science, 2015, 6, 3805-3815.

Ammonia is an attractive answer to the question of how best to store and transport hydrogen so it can be used as a sustainable fuel. However, the catalytic decomposition of ammonia to release its stored hydrogen using transition metals (ruthenium is the most active metal) typically requires very high temperatures. This paper details a new approach to ammonia decomposition catalysis using lithium imide (Li2NH), showing a decrease in the temperature of 90% conversion of around 50°C compared to ruthenium. In this work, in situ neutron powder diffraction was used to demonstrate that under operating conditions the catalyst adopts a non-stoichiometric mixed amide-imide phase. Furthermore, H-D isotope exchange reactions showed that the entire bulk of the catalyst interacts with the ammonia as it decomposes, in contrast to common surface-only catalytic cycles.

Areas of interest

Nanoscale Science; Noncovalent Bonding; Self-Assembly; Self-Organisation; C60; Electron Beam Resists; Liquid Crystals; Self-Assembled Monolayers; Nano-Tribology

Representative paper: Novel polystyrene sulfonate-silica microspheres as a carrier of a water soluble inorganic salt (KCl) for its sustained release, via a dual-release mechanism

C. Sui, J.A. Preece, Z. Zhang, RSC Advances, 2017, 7, 478-481.

This paper reports for the first time the encapsulation of a water soluble inorganic salt in a hybrid organic-inorganic microcapsule.  By careful tuning of the microcapsule chemistry it proved possible to modulate the release of the salt, which we propose involves two stages: initially by leaching out as complex with an encapsulated polyanion, and subsequently as the free salt.  The work has been patented, and industry has shown an interest.

Areas of interest

Green Chemistry; Sustainability; Biomass; energy (fuel cells, batteries); water purification.

Representative paper: Mechanistic insights into porous carbons from gelatin

A.E. Danks, M.J. Hollamby, B. Hammouda, D.C. Fletcher; F. Johnston-Banks; S.R. Rogers, Z. Schnepp; J. Mater. Chem. A 5, 11644-11651, 2017.  

In this paper we show how the biopolymer gelatin can be utilised to produce functional carbon foams with multimodal porosity. The mechanism of the formation of these foams is assessed through the use of small angle neutron scattering alongside other techniques. We illustrate that the choice of metal nitrate can be exploited to control foam macrostructure, attributed to synergistic interaction of metal ions with the gelatin polypeptide, which changes the viscoelastic properties.

Areas of interest

Functional materials, porous materials, metal-organic frameworks, molecular conductors, crystallography, energetics, in situ X-ray diffraction, crystallisation, formation mechanisms, high pressure, synchrotron techniques.

Representative paper: In-Situ Observation of Successive Crystallisations and Metastable Intermediates in Metal-Organic Framework Formation

H. H.-M. Yeung,* Y. Wu, S. Henke, A. K. Cheetham, D. O’Hare, R. I. Walton
Angewandte Chemie, International Edition 2016 55, 2012-2016. DOI: 10.1002/ange.201508763

Understanding the driving forces controlling crystallization is essential for the efficient synthesis and design of new materials, particularly metal–organic frameworks (MOFs), where mild solvothermal synthesis often allows access to various phases from the same reagents. Using high‐energy in situ synchrotron X‐ray powder diffraction, we monitor the crystallization of lithium tartrate MOFs, observing the successive crystallization and dissolution of three competing phases in one reaction. By determining rate constants and activation energies, we fully quantify the reaction energy landscape, gaining important predictive power for the choice of reaction conditions. Different reaction rates are explained by the structural relationships between the products and the reactants; larger changes in conformation result in higher activation energies..

Contact

Enquiries about specific aspects of their research areas should be addressed to individual research group leaders. For more general enquiries about working with the Materials Chemistry Section, please contact the Head of the Section, Professor Peter Raymond Slater. Information on various postgraduate (PhD and Masters) degree opportunities can be found on our postgraduate opportunities page.