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Dense electrolyte films ∼15 μm thick made of samarium-doped ceria (SDC) are fabricated by spin-coating. The SDC powders are synthesized by the glycine nitrate combustion process. It is found that nanoscale SDC powders can be obtained at 1000 °C. Cells constructed with an SDC electrolyte, a NiO + SDC composite anode, and an SSC–SDC/SSC bi-layer cathode are fabricated and tested at temperatures from 400 to 650 °C. SEM micrographs show that the SDC electrolyte layer adheres well to the porous anode and the cathode. The maximum power densities of the cell are 38, 84, 185, 303, 438, and 549 mW cm −2 at 400, 450, 500, 550, 600, and 650 °C, respectively. Analysis of the impedance spectra indicates that the electrode polarization dominates the total cell resistance at temperatures below 550 °C, and the ohmic resistance dominates the total cell resistance above 550 °C. The activation energies of the resistances show that the cell performance is significantly controlled by the electrode polarization resistance. Durability tests are performed over 950 h and indicate that the power density and the voltage gradually degrade with time at a rate of ∼0.03 mW cm −2 h −1 and ∼0.07 mV h −1 , respectively. Hence, a low-temperature solid oxide fuel cell has been developed.

The Sm 0.5 Sr 0.5 CoO 3− δ (SSC) with perovskite structure is synthesized by the glycine nitrate process (GNP). The phase evolution of SSC powder with different calcination temperatures is investigated by X-ray diffraction and thermogravimetric analyses. The XRD results show that the single perovskite phase of the SSC is completely formed above 1100 °C. The anode-supported single cell is constructed with a porous Ni–yttria-stabilized zirconia (YSZ) anode substrate, an airtight YSZ electrolyte, a Sm 0.2 Ce 0.8 O 2− δ (SDC) barrier layer, and a screen-printed SSC–SDC composite cathode. The SEM results show that the dense YSZ electrolyte layer exhibits the good interfacial contact with both the Ni–YSZ and the SDC barrier layer. The porous SSC–SDC cathode shows an excellent adhesion with the SDC barrier layer. For the performance test, the maximum power densities are 464, 351 and 243 mW cm −2 at 800, 750 and 700 °C, respectively. According to the results of the electrochemical impedance spectroscopy (EIS), the charge-transfer resistances of the electrodes are 0.49 and 1.24 Ω cm 2 , and the non charge-transfer resistances are 0.48 and 0.51 Ω cm 2 at 800 and 700 °C, respectively. The cathode material of SSC is compatible with the YSZ electrolyte via a delicate scheme employed in the fabrication process of unit cell.