UK Fuel Cell Research & Development

Transcription

1 UK Fuel Cell Research & Development John Kilner Department of Materials Imperial College, London SW7 2AZ, UK And UK Energy Research Centre (UKERC)

2 United Kingdom Energy Research Centre UKERC Headquartered at Imperial Imperial, Oxford, Edinburgh, Manchester, Lancaster, Policy Studies Institute UKERC aims to take a whole systems view. Multidisciplinary team mix of scientist, engineers, social scientists, economists. Three vertical themes Three cross cutting themes

3 UKERC THREE VERTICAL THEMES Demand Reduction Brenda Boardman, Environmental Change Institute, Oxford Future Sources of Energy Robin Wallace, Edinburgh Infrastructure and Supply Nick Jenkins, UMIST

4 UKERC THREE X-CUTTING THEMES Energy Systems and Modelling Paul Ekins, Policy Studies Institute Environmental Sustainability David Howard, Lancaster Environment Centre Material for Advanced Energy Systems John Kilner, Imperial College

5 UKERC Research Themes Materials For Advanced Energy Systems (JAK) For hydrogen economy High temp electrolysers (Materials) Oxygen ion and protonic Bio inspired generation (Chemistry) Storage (Chemistry) Materials for CCS systems Mixed Conducting membranes for oxygen separation Materials for Nuclear Energy Radiation hard (Materials) Materials for 3 rd Gen PV s Materials processing (Physics) UK Energy Research Centre

6 Future sources of Energy Theme Fuel cells a component of this activity run by Nigel Brandon (IC) UKERC Compiling a Research Atlas of the UK research into energy related R & D. Fuel cell Landscape complied by Nigel Brandon Published on the UKERC Web site Roadmaps Research register of research grants in the energy sector

7 Fuel Cells powering a greener future

8 Supergen Consortium Fuel Cells Powering A Greener Future EPSRC funding 1.9M DSTL funding 0.2M 4 years from October 2005 Industry Rolls-Royce Fuel Cell Systems (Dr. Stephen Pyke) Johnson-Matthey (Dr. Dave Thompsett) Ceres Power (Dr. Ahmet Selcuk) DSTL (Dr. Barry Lakeman) Academia Engineering (Prof. Nigel Brandon) University of Newcastle (Prof. Keith Scott) Materials (Prof. Alan Atkinson) University of Nottingham (Prof. Kwang-Leong Choy) University of St. Andrews (Prof. John Irvine, Dr. Richard Baker)

9 Supergen consortium aims To bring together a world-class multidisciplinary UK team across the academic and industrial sectors to address key technical barriers facing the realisation of a UK fuel cell industry. To exploit synergies in our work addressing three (traditionally distinct) fuel cell technologies; High-Temperature Polymer Electrolyte Membrane Fuel Cells (HT- PEMFCs), High-Temperature Solid Oxide Fuel Cells (HT-SOFCs) Intermediate-Temperature Solid Oxide Fuel Cells (IT-SOFCs). To develop high quality researchers trained in fuel cell technology. To communicate our research to the academic, industrial and general communities.

10 Supergen consortium activities (1) WP1 Zero Leakage SOFC To reduce ceramic electrolyte leakage to equivalent of <1% efficiency loss green layer processing and characterisation, constrained sintering, novel processing, nano-powders process optimisation, lower sintering temperature, co-sintering mechanical properties. WP2 Significantly Improved Fuel Cell Durability Improve durability from state-of-the-art by a factor of >2 durable SOFC anodes, resistance to coking and sulphur ageing tests, phase analysis, electron microscopy thermal and redox cycling (particularly SOFCs) cell and stack modelling, stack design tools control strategies to improve durability lifetime prediction.

11 Supergen consortium activities (2) WP3 Significantly Improved Fuel Cell Performance extend PEM to 130 C (automotive) and 200 C (stationary) reduce SOFC to 500 C MEAs for HT-PEMFCs, cathodes for HT-PEMFCs (resistant to deactivation) and IT-SOFCs, electrode modelling, novel routes to powders and components. WP4 Enhanced Fuel Flexibility Liquid hydrocarbons, alcohols, biofuels direct hydrocarbons in SOFC, reforming resistance to sulphur and other impurities less clean fuels, biogas ethanol in SOFC and PEM. WP5 Dissemination, Outreach and Training Workshops and seminars, website, UK and overseas links, UKERC.

12 SOFC Cell Design Tubular Siemens-Westinghouse Planar Global Metal supported thin film Ceres Power HT-SOFC 1000 C Advantages sealing durability IT-SOFC 550 C

13 Materials Issues for SOFC and ITSOFC High temperature SOFC s Durability Sealants ITSOFC s (5-600 C) Activity at low temperatures Oxygen ion conductivity in electrolytes and mixed conductors (cathodes) Generic Redox and sulphur tolerant Anodes (St.Andrews) Fundamental understanding of electrode processes (Imperial) Characterisation of porous electrodes Modelling of whole cells

14 Low temperature Cathodes for ITSOFC s Research theme in UKERC, Supergen, SOFC 600 (EU) Major cause of loss at the lowest temperatures due to cathode polarisation Need more active cathode materials for reduction of oxygen molecule Mixed conducting perovskites Oxygen diffusion and electronic conductivity Mixed conducting composites Electrolyte and electronic conducting material Cermets Ceramic-ceramic composites

15 Perovskite materials A 3+ B 3+ O 3 Rare Earth ions La 3+, Ce 3+, Pr 3+, Nd 3+, Sm 3+, Eu 3+, Gd 3+, Tb 3+, Dy 3+, Ho 3+, Er 3+, Yb 3+, Lu 3+ Al 3+, Cr 3+, Fe 3+, Ga 3+, Co 3+, Mn 3+, In 3+, Sc 3+

16 Combinatorial searching for new perovskite mixed conductors y x Arrays of inkjet printed dots Changing compositions La 1-x Sr x Co 1-y Fe y O 3

17 High throughput screening system

18 Discovery of new functional oxides by combinatorial methods (EPSRC) Prof. Kilner Projects

19 Neural network predictor Performance of the neural network used to predict the diffusion coefficient of an unseen dataset Rossiny et al Proc SOFC 7 Lucerne 2006

20 Critical issues in electrode modelling Fundamental understanding of electrochemistry E.g for cathodes what is the rate limiting step? How does this related to bulk and surface structure of the electrode material Electrode microstructure Quantitative microstructural characterisation Single phase and composites

21 Adler Model R chem Figure: Schematic representation of the ALS model [S.B. Adler, limitations of charge transfer models for mixedconducting oxygen electrodes, solid state ionics 135 (2000) ] = RT τ F ac D k ( ε ) 2 0 D Oxygen self-diffusion coefficient k Oxygen surface exchange coefficient τ Tortuosity ε Fractional porosity a Internal surface area/unit volume C O Molar concentration of oxygen ions For Low R chem need Dk product > cm 3 sec -2

22 FIB Secondary Electron Image Following Milling

23 Isotope exchanged sample 500 C 5 mins

24 Isotopic Fraction Map of Ion Polished Edge Line y= 4µm Line y= 8 µm Line y= 9µm

25 Composite Cathodes Porous composite materials Used as electrodes in both High temp and ITSOFC Understanding and characterisation a problem

26 FIB sectioned porous anode structure Reconstruction of the 3-D structure of an SOFC anode from dual beam FIB sectioning. Ni green, YSZ grey and pores blue Wilson et al Nature Materials, (7): p

27 Commercialisation Ceres Power Targets RRFCS GT-SOFC 1MW pressurised Hybrid system

28 Main Industrial Organisations Solid Oxide Ceres Power Fuel Cells Scotland Ltd Quinetic Rolls Royce Fuel Cell Systems St Andrews Fuel Cells Ltd Alkaline Alternative Fuel Systems Ltd. Eneco ltd PEM CMR Fuel Cells Ltd Dart Sensors Ltd. Intelligent Energy ITM Power PLC JM Fuel Cells Quinetic Voller Energy Govt. Labs Defence Science and technology Laboratory [DSTL] National Physical Laboratory (NPL)

29 Rolls-Royce SOFC-GT pressurised hybrid Predictions: electricity SOFC T air C electricity 70% SOFC, 30% GT η e = 60-70% LHV on natural gas at 5 MW Needs high T SOFC de-s HEX exhaust Segmented-in-series flat tube design fuel Achieved multi-kw pressurised operation

30 RRFCS Development Programme Objective 1MW SOFC Unit

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32 Ceres Power Metal-supported SOFC Ce 0.9 Gd 0.1 O 2-x electrolyte. La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ + CGO cathode, µm thick. Cr ferritic stainless steel foil support, µm thick. Ni + CGO anode, µm thick. Stainless steel Stainless steel-supported