EPSRC

Current Support

Emergent Nanomaterials (Critical Mass Proposal) (EP/R023646/1)

Partners: Prof. John Irvine, University of St Andrews (Lead), Prof. Ian Metcalfe, University of Newcastle, Prof. Davide Mariotti, University of Ulster, Prof. Steve Parker, University of Bath.

Starts: 02 July 2018 Ends: 01 July 2022

Value (£): 556,452 (Imperial).

Summary: In recent work we have identified a very powerful and extensive phenomenon, the constrained production of nanoparticles that opens up a new field impinging on chemistry, materials science and physics. The dispersion, stability, versatility and coherence with the substrate impart quite significant properties to the emergent nanoparticles opening up a major new topic. The process is driven by the lattice decomposition of a metal oxide under reduction by various means. Conventional thinking considers this as a simple phase separation; however, by careful control of the defect chemistry and reduction conditions, a very different process can be achieved. These nanoparticles emerge from the substrate in a constrained manner reminiscent of fungi emerging from the earth. The emergent nanoparticles are generally dispersed evenly with a very tight distribution often separated by less than one particle diameter.

Here we will explore the composition and reaction space conditions necessary to optimise functionality, structure and applocability. We will also seek to better understand this phenomenology relating to correlated diffusion, driving energetics and mechanism of emergence. Further work is necessary to understand the critical dependence of composition in a very extensive domain of composition space depending upon charge and size of the A-site cations, oxygen stoichiometry and transition metal redox chemistry. Of particular importance is to understand the nature of the interaction between the nanoparticle and the substrate addressing the evolution of the nanoparticles from the surface and how the particles become anchored to the substrate. Exolved metals can react to form compounds whilst maintaining the integrity of the nanostructural array and this offers much potential for further elaboration of the concept.

We will investigate the important catalytic, electrocatalytic and magnetic physics properties arising at constrained emergent particles, driven by dimensional restriction. Emergent nanomaterials provide very significant surface-particle interactions and promise new dimensions in catalysis. The electrochemical reactions in devices such as batteries and fuel cells are restricted to the domain very close to the electrolyte electrode interface. Emergent materials can be applied in exactly this zone.

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Understanding the critical role of interfaces and surfaces in energy materials (EP/R002010/1)

Partners: Prof. Stephen Skinner (lead), Dr. Ainara Aguadero, Dr. Johannes Lischner, Prof. Mary Ryan (all Department of Materials, Imperial College London).

Starts: 01 October 2017 Ends: 30 September 2022

Value (£): 1,304,889

Summary: ‘Energy materials’ encompass a wide range of technologies, ranging from thermoelectrics to fuel cells, batteries, photovoltaics and magnetocalorics, among others. Many of these energy materials are developed as multi-component solid state devices and these devices inherently possess a number of electrochemically active interfaces. It is these interfaces, e.g. solid/solid, liquid/solid or gas/solid, that control the function of the device, and are typically the source of degradation. Many current techniques used to analyse these devices and their components rely on idealised systems in high vacuum environments to gain information on the near surface chemistry. This necessitates the use of post-mortem operation analysis and clearly represents a significant mismatch from the conditions under which devices operate. Increasingly it is acknowledged that in-operando measurements are required, but that the measurements are themselves difficult and demanding. It is our intention to develop expertise with in-operando characterisation of energy materials. This will build on our existing expertise and capability in surface analysis and in-situ measurements. As an example, a fuel cell operating at 823 K will be subjected to temperature gradients, cation segregation, potential gradients, poisoning and chemical changes induced by these conditions, all of which are inter-related, but separating the individual contributions has so far proved impossible. Similar issues involving the interface and surface chemistry of solid state batteries, permeation membranes and co-electrolysers will also be addressed using these techniques. By developing in-operando correlative characterisation we aim to deconvolute these processes and provide detailed mechanistic understating of the critical processes in a range of energy systems.

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Solid Oxide Interfaces for Faster Ion Transport (SOIFIT) (EP/P026478/1)

PartnersProf. Stephen Skinner (Lead), Dr. Ainara Aguadero, Prof. John Kilner (all Department of Materials, Imperial College London).

Starts: 03 July 2017 Ends: 02 July 2022

Value (£): 1,001,181

Summary: Solid state electrochemical devices are set to revolutionise clean energy conversion and storage and provide a pathway to minimise carbon emissions whilst sustaining global energy requirements. Devices such as the Solid Oxide Fuel Cell (SOFC) and the Solid Oxide Electrolysis Cell (SOEC) and all solid state lithium and sodium batteries will play an increasingly important role in the energy economies of Japan, Europe and the USA, for domestic industrial and transport applications. Example devices are all solid state Li batteries for electric vehicles, and SOFC stacks for domestic CHP applications. Such devices based on solid oxide electrolytes rely upon the rapid transport of charged atoms (ions) across either the solid/gas and/or solid/solid interfaces. In addition to the optimisation of such interfaces for fast ion transport, they also play an important role in the degradation of devices under operating conditions. Examples of these degradation processes are the drop in performance of SOFC electrodes caused by surface decomposition of the active oxides, the formation of short circuit Li metal dendrites in Li batteries, and the delamination of electrodes in SOEC. The focus of this proposal will be to provide a full and fundamental study of both types of interface by state-of-the-art characterisation techniques, combined with cutting edge theoretical simulations, to investigate the detailed atomic structure electronic structure chemical composition and mass and charge transport. This is a very challenging task as the materials used in practical devices are complex multi-component oxides. Examples include the double perovskite oxides, such as GdBaCoO5+d used as a SOFC cathode and an SOEC anode, and the garnet La3Zr2Li7O12 used as an electrolyte in Li batteries. In addition the investigation of these interfaces after exposure to simulated operating conditions, or real operation in devices, will enhance the lifetime of devices and lead to more viable commercial products. A consortium of universities and research institutes will form the core of this collaboration. The lead partners are the Department of Materials at Imperial College London and the International Institute for Carbon-Neutral Energy Research (I2CNER) Kyushu University. Outside the lead UK-Japanese team will be the Paul Scherrer Institut (PSI/ETH) Zurich and Massachusetts Institute of Technology. This consortium will ensure that the researchers in the collaborating countries have access to the latest high performance equipment and theoretical tools. It will also allow young researchers from all the participants to travel between the partners, and meet senior scientists involved in this important research topic. It is hoped that the formation of this consortium will form a “critical mass” of effort to solve what have, up to now, been intractable problems.

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Reduced Energy Recycling of Lead Acid Batteries (RELAB) (EP/P004504/1)

Partners: Prof. Jason Riley, Department of Materials, Imperial College LondonProf. Geoff Kelsall, Dr. Jason Hallett, Prof. Nilay Shah, Department of Chemical Engineering, Imperial College London.

Starts: 01 December 2016 Ends: 30 November 2020

Value (£): 1,295,519

Summary: The need to reduce energy demand is felt most keenly in the energy intensive industries (EEIs), of which the manufacturing of metals such as iron and steel, as well as non-ferrous metals, are a large constituent. The lead industry has in the last few decades developed effective processes for the recycling of metallic lead from (principally) lead acid batteries. The batteries are crushed (to remove the plastic), de-sulfurised, smelted and then refined to produce lead bullion which can be reused to make new batteries. Whilst very high rates of recycling are achieved, the entire process in very energy intensive, mainly from the milling and the smelting but also from the need to eliminate any lead-to-air emissions. Whilst the principles of this pyrometallurgical process have remained relatively unchanged for centuries, this proposal seeks to develop a novel solution-based electrochemical route to lead recycling using deep eutectic solvents (DESs).

Deep eutectic solvents have been applied to a number of different technological applications, owing to their relatively low cost, ease of handling, low environmental impact and, most importantly, their ability to dissolve a wide range of inorganic compounds – including oxides. We propose to dissolve lead paste – from lead acid batteries – in DESs and design novel electrochemical cells for the extraction of high purity metallic lead. This will be done in conjunction with Envirowales Ltd, a lead-acid battery recycler, as our project partner.

The main objective of the project is to develop a new electrochemical technology for lead-acid battery recycling based on a solution-based processing. We aim to understand the behaviour of speciation of Pb within the solvent, as well as the effects of secondary cations and electrode poisoning. We aim to design and build a number electrochemical cells (from bench-top to pilot plant prototype), that will replace the smelting steps in the current high temperature process. This will be supported by accurate total energy modelling of the current pyrometallurgical process with which to benchmark our energy gains by switching to the new technology. We envisage that not only will this technology have a lower overall energy demand, but will also be cleaner, due to a significant reduction in lead-to-air emissions.

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Control of structure, strain and chemistry: a route to designer fuel cell interfaces (EP/M014142/1)

Partners:Prof. Stephen Skinner (lead), Dr. Ainara AguaderoProf. John Kilner, Prof. Mary Ryan, Department of Materials, Imperial College LondonProf. Chris Nicklin, Diamond Light Source.

Starts: 01 April 2015 Ends: 31 March 2019

Value (£): 1,076,043

Summary: A fuel cell consists of three primary components: the air electrode, fuel electrode and ion transport electrolyte. The function of these components is primarily to carry current, reduce oxygen and oxidise a fuel. As these devices are typically constructed using traditional manufacturing techniques there is little control of the atomic scale processes that occur at the interfaces between each of these components. As the electrochemistry that controls the fuel cell operation is correlated with the structure and strain at the interfaces between the components and with the electrode/environment interfaces, a clear understanding of these processes at the atomic scale is essential if optimised, high performance, low cost fuel cells are to be produced. In this work we will use a complementary suite of advanced techniques, including X-ray photoelectron spectroscopy, Low energy ion scattering and crystal truncation rods to probe the structure of the interfaces, including buried interfaces, and link this with surface chemistry and fuel cell performance. Once these key factors are understood we will apply this knowledge to the design and manufacture of 2D and 3D electrode structures. We will engage with our international partners to complement the work undertaken at imperial and test devices with our industrial partner, AFC Energy.

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Previous EPSRC Support

EP/M013839/1 Understanding CO2 Reduction Catalysts (P)
EP/M014304/1 Tailoring of microstructural evolution in impregnated SOFC electrodes (C)
EP/K024493/1 Manufacturing R&D Facility: Electron Beam Epitaxy (C)
EP/K004913/1 A Facility for Ambient Pressure Photoelectron Spectroscopy (APPES) (R) (P)