August 2008 Fuel Cells Bulletin11

NIST, Liverpool find oxygen ions looser at lower temperatures

Researchers at the US National Institute of Standards and Tech-

nology (NIST), in collaboration with the University of Liverpool in the UK, have uncovered a novel structure that moves oxygen ions through the cell at much lower temperatures than previously thought possible. The finding may be key to solving fuel cell reliability issues, and lead to reduced operating costs in high-performance solid oxide fuel cells.

Conventional SOFCs need high temperatures – about 850°C – and hence long startup times, ranging from 45 min to 8 h. Such temperatures necessitate more expensive materials and higher operating costs, so stationary fuel cell research is focused on lowering operating temperatures as well as shortening startup. The US Department of Energy’s goal is to cut the startup time to 2 min.

Chemists at the University of Liverpool fab-ricated a new oxygen ion electrolyte material of lanthanum, strontium, gallium and oxygen, and sent it to the NIST Center for Neutron Research (NCNR) to investigate. Also involved were researchers at the University of Maryland and University College London.

The oxygen ions in the new materials become mobile at 600°C, much lower than previously studied materials. Researchers suspected the reason lay in the location of the oxygen ions in the compound’s crystal framework. The neutron probes allowed them to determine the basic crys-tal structure that held the lanthanum, strontium, gallium and oxygen atoms, although the exact nature of the extra oxygen ions was unclear.

NCNR researchers recommended borrowing a radio astronomy technique, maximum entropy analysis. ‘When astronomers are not able to visu-alize a specific part of an image because it consti-tutes such a small part of the total information collected, they utilize a part of applied mathe-matics called information theory to reconstruct a sharper image,’ explains NCNR researcher Mark Green. ‘The combination of neutron diffraction and maximum entropy analysis not only allowed us to determine the location of additional oxy-gen ions outside of the basic framework, but revealed a new mechanism for ion conduction.’

The research, authored by Xiaojun Kuang et al., was published recently in Nature Materials [DOI: 10.1038/nmat2201].

Contact: Professor Matthew J. Rosseinsky, Department of Chemistry, University of Liverpool,

UK. Tel: +44 151 794 3499, Email: rossein@liv.ac.uk, www.liv.ac.uk/chemistry

Or contact: Dr Mark A. Green, NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, USA. Tel: +1 301 975 4297, Email: mark.green@nist.gov, www.ncnr.nist.gov

SECA selects UTC Power/Delphi, Rolls-Royce projects

The US Department of Energy has selected two more projects for its

Solid State Energy Conversion Alliance (SECA) Program portfolio. These will be led by UTC Power, in partnership with Delphi, and by Rolls-Royce Fuel Cell Systems (US) Inc. The Rolls-Royce proj-ect will include work at Ohio’s Stark State College Fuel Cell Prototyping Center, which is also supported through a National Science Foundation grant.

The SECA project portfolio, including the Rolls-Royce and UTC Power projects, will research, develop and demonstrate solid oxide fuel cell technologies that can support power gen-eration systems as large as several hundred MW.

SECA was established by DOE in 2000 to research and develop low-cost, modular, fuel-flex-ible SOFC systems by 2010. In 2005, SECA was accelerated to deliver MW-class fuel cell systems in response to the emerging national need for low-cost carbon capture technologies, along with more efficient use of fuels abundantly available in the US and the need to address reduced water use in power plants. SECA is managed by DOE’s National Energy Technology Laboratory (NETL).

The UTC Power-led project, valued at more than $22m over two years, is among the larg-est DOE projects ever awarded to the firm. UTC Power and United Technologies Research Center will partner with Delphi; both UTRC and Delphi bring significant SOFC development experience, and are already SECA participants. Danish-based Topsoe Fuel Cells will provide advanced materials for evaluation by the partners.

The team will design a subscale, proof-of-concept system; develop manufacturing capabili-ties; resolve issues related to cost, performance and manufacturability of larger-scale fuel cells; and develop, fabricate and test a scaled stack suitable for use in a full-scale system.

Contact: UTC Power, South Windsor, Connecticut, USA. Tel: +1 860 727 2200, www.utcpower.com

Or contact: Rolls-Royce Fuel Cell Systems (US) Inc, North Canton, Ohio, USA. Tel: +1 330 491 4810, www.rolls-royce.com/energy/tech/fuelcells.jsp

For more on SECA, go to: www.seca.doe.gov

CONFERENCE REPORT: Lucerne Fuel Cell Forum

This year the main focus of the Lucerne Fuel Cell Forum 2008 was on solid

oxide fuel cells, in the form of the 8thEuropean SOFC Forum – the largest gathering of the SOFC community in the world this year. The event was well attend-ed, with nearly 500 researchers, developers and interested business folk in attendance, including a healthy number of students getting well acquainted with the latest developments in SOFC technologies.

The 120 oral presentations in two parallel technical sessions covered all the key areas. The research topics covered in the techni-cal sessions included modeling, analysis and methods, intermediate-temperature SOFCs, anodes, cathodes, electrolytes, interconnects and coatings, sealing and flows, electrolysis and proton condustors. On the applications side there were ses-sions on SOFC solutions, industrial expe-rience, innovative applications and designs, manufacturing, stack and cell design, micro SOFCs, testing, durability and integrity, and fuels and reforming. There were also 142 poster papers presented in two poster sessions, and 30 exhibitors, including one from China, to keep delegates occupied.

This year the Christian Friedrich Schoenbein Medal of Honor went to Professor Mogens Mogensen of Risø National Laboratory in Denmark, in rec-ognition of his outstanding contributions to SOFC science and technology over the last 30 years.

The conference proceedings/CD are available from the EFCF website, priced at CHF300.

Lucerne Fuel Cell Forum 2009The Call for Papers has already been issued for the Lucerne Fuel Cell Forum 2009, which will take place 28 June–2 July.

The 2009 event will comprise an inter-national congress on the science, tech-nology and applications of all fuel cell technologies, with a parallel exhibition, and a fuel cell tutorial. The overall theme is ‘Fuel Cell Solutions’. The organizers are already inviting interested parties to submit one-page abstracts in English, as an MS Word document attached to an email, by 30 November 2008.

For more information, or to submit an abstract for the 2009 event, go to: www.efcf.com

NEWS / REPORT