Microstructure and properties of suspension plasma sprayed SrTiO_3 -based anodes for intermediate-temperature solid oxide fuel cells

摘要

Lanthanum doped strontium titanate (LST) is considered as a promising, redox-stable perovskite material for direct hydrocarbon oxidation anodes in intermediate-temperature solid oxide fuel cells (IT-SOFCs). In this study, the nano-sized LST and SDC (samarium doped ceria) powders are produced by sol-gel method and glycine-nitrate process, respectively. LST/SDC composite anodes were prepared by suspension plasma spraying (SPS). The effects of annealing conditions on the phase structure, microstructure and chemical stability of LST/SDC composite anode were examined. The XRD results indicate that the suspension plasma-sprayed LST/SDC coatings present the same phase structure with original powders. LST exhibits a good chemical compatibility with SDC. The coatings present a finely porous structure which benefits high necessary gas permeability and long three phase boundary for the anode reaction. The single cell which is assembled with LST/SDC anode, La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_3 electrolyte and La_(0.8)Sr_(0.2)CoO_3/SDC cathode showed a good performance at 650-800°C.