Chemical compatibility and properties of suspension plasma-sprayed SrTiO3-based anodes for intermediate-temperature solid oxide fuel cells

• Nano-sized LST and SDC powders are produced for SPS.
• Ni reacted with LSGM electrolyte at or above 600 °C.
• LST exhibits a good chemical compatibility with SDC and LSGM.
• SPS was employed to prepare the LST–SDC composite anode.
• Test cell shows a power density of 221 mW cm−2 at 800 °C and increase by 37% with the annealed anode.

La-doped strontium titanate (LST) is a promising, redox-stable perovskite material for direct hydrocarbon oxidation anodes in intermediate-temperature solid oxide fuel cells (IT-SOFCs). In this study, nano-sized LST and Sm-doped ceria (SDC) powders are produced by the sol–gel and glycine–nitrate processes, respectively. The chemical compatibility between LST and electrolyte materials is studied. A LST–SDC composite anode is prepared by suspension plasma spraying (SPS). The effects of annealing conditions on the phase structure, microstructure, and chemical stability of the LST–SDC composite anode are investigated. The results indicate that the suspension plasma-sprayed LST–SDC anode has the same phase structure as the original powders. LST exhibits a good chemical compatibility with SDC and Mg/Sr-doped lanthanum gallate (LSGM). The anode has a porosity of ∼40% with a finely porous structure that provides high gas permeability and a long three-phase boundary for the anode reaction. Single cells assembled with the LST–SDC anode, La0.8Sr0.2Ga0.8Mg0.2O3 electrolyte, and La0.8Sr0.2CoO3–SDC cathode show a good performance at 650–800 °C. The annealing reduces the impedances due to the enhancement in the bonding between the particles in the anode and interface of anode and LSGM electrolyte, thus improving the output performance of the cell.