Overview of the development of solid oxide fuel cells at Forschungszentrum Juelich

The SOFC group at FZJ has assembled and tested more than 190 SOFC stacks during the last 10 years, rated between 100 W and 15 kW. The topics of high performance materials, corrosion, materials matching and cost-effectiveness, including manufacturing processes etc. are being continuously addressed. Use of the ferritic steel JS-3 that was developed at FZJ has resulted in reduced degradation rates around 1% per 1000 hours over stack lifetimes of more than 8000 hours. However, the target of the development is directed towards 0.25%/ 1000 h for commercial operation in stationary applications. Large stacks of 5 kW and above have been operated since 2002 and also been successfully delivered and operated in Finland and Korea. In parallel, light-weight stacks are being developed in the so-called 'cassette design' line for SOFC-APU. Several 1 to 20 kW SOFC laboratory systems are in preparation, partly using the integrated stack concept which combines all hot parts of the balance of plant into one single module. All stack tests are accompanied by disassembly and post-operative examinations investigating such phenomena as cathode degradation, corrosion, and other aging phenomena. These analyses give a deep insight into the interaction of the stack materials and supply vital data on prolonged stack operation over some tens of thousand hours.