Long term stability has been a crucial issue for the future applications of the solid oxide fuel cells (SOFCs). Current collectors for the cathodes have been among the most vulnerable components of the SOFCs due to their operation in oxidizing atmospheres at relatively high temperatures. Ag and Ag based LSM (lanthanum-strontium manganite) composites were studied to develop highly stable and low-cost current collectors compatible with other fuel cell components. In this study, no degradation was observed in the electrical conductivity and the porous microstructure of the Ag-LSM composite current collectors after 600 hours of operation at 800oC in air.

Solid-oxide fuel cell (SOFC) performance depends greatly upon electrode design. The composite anode plays a critical role in fuel reforming, especially when hydrocarbons are included in the fuel mixture. Because direct observation of fuel reforming in a functioning SOFC is difficult, if not impossible, an alternative experimental configuration is needed to evaluate anode performance. The Separated Anode Experiment (SAE) is designed to isolate and study porous-media transport and heterogeneous reforming chemistry in SOFC anodes. Although the experiment does not incorporate a dense electrolyte membrane or a cathode, it is configured to replicate important aspects of anode behavior in a fully operational SOFC. The experiment is also designed to facilitate model-based interpretation of the results. Comparisons of two significantly different anode structures are used to illustrate the experimental and modeling capabilities.

According to the recent hydrogen and methanol economy, the proton conducting materials appear very interesting as an electrolytic membrane and/or an electrode component of fuel cells, CO2/Syngas converters and water steam electrolysers. Prior to the long lifetime requirements their structural and mechanical behaviors as a function of operating condition: high temperature and high water vapor pressure, have to be well determined. Consequently, we designed the autoclave working till 620°C and 50 bars of H2O pressure equipped with a sapphire window allowing in situ Raman scattering measurements. It should be stressed that Raman scattering is an optical technique very efficient to detect both long and short range order structural modifications. The technical and scientific challenges/difficulties encountered during the studies performed on proton conducting zirconates are discussed.

Solid oxide fuel cells (SOFCs) have many advantages when compared to other fuel cell technologies, particularly for distributed stationary applications. As a consequence they are becoming ever more economically competitive with incumbent energy solutions. However, as with all technologies, improvements in durability, efficiency and cost is required before they become feasible alternatives. Such improvements are enabled through improved understanding of the critical material interactions occurring during operation. Raman spectroscopy is a noninvasive and non-destructive optical characterization tool which is ideally suited to the study of these critical chemical processes occurring within operational SOFCs. In this paper we will discuss advantages of using Raman characterization for understanding these important chemical processes occurring within SOFCs. We will present the specific examples of the type of measurement possible and discuss the direction of future research.

Three-dimensional numerical simulations can provide information which cannot be obtained from experiments and can be a powerful tool for investigating reaction phenomena in solid oxide fuel cell (SOFC) electrodes. In the present study, a dual-beam focused ion beamscanning electron microscope is used to reconstruct the three dimensional microstructures of the SOFC electrodes, and their polarization characteristics are predicted by a lattice Boltzmann method. Predicted overpotentials for Ni-YSZ anode and mixed ionic and electronic conducting cathode (La0.6Sr0.4Co0.2Fe0.8O3-δ; LSCF6428) are compared with the experimental data for validation. In addition, three-dimensional distributions of electrochemical potential and current densities inside the electrode microstructures are obtained. Large non-uniformities of potential and current distributions are found in the Ni-YSZ anode, while those became much uniform in the LSCF cathode. The present method can be expected as a powerful tool for investigating local potential fields which affect local reactions and diffusion processes as well as local physical properties of the SOFC electrodes.

In-situ micro Raman spectroscopy has been adopted as one of the most powerful analytical techniques with high spacial resolution under controlled atmospheres. In the present study, phase transformation of NiO doped yttria stabilized zirconia (YSZ) was monitored by in-situ micro-Raman spectroscopy. Raman spectra change caused by the phase transformation from the cubic phase to the tetragonal phase was observed for the NiO doped YSZ during annealing at a high temperature of 1173 K under reducing atmosphere.