Fabrication and characterization of a Sm0.2Ce0.8O1.9 electrolyte film by the spin-coating method for a low-temperature anode-supported solid oxide fuel cells

I–V curves and the corresponding power densities for the cell with an SDC electrolyte (a) at temperatures from 400 to 650°C, and (b) under different air flow rates at 650°C. [Display omitted] ► Nanoscale SDC powders with a low degree of agglomeration were synthesized at 1000°C. ► The chemical state change of Ce in SDC electrolyte is investigated and reported for a LT-SOFC after operation. ► The cell performance test was operated over 1600h. ► The durability test was examined over 950h. ► The maximum power density achieved 608mWcm−2 at 650°C. Dense electrolyte films ∼15μm 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 549mWcm−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 950h and indicate that the power density and the voltage gradually degrade with time at a rate of ∼0.03mWcm−2h−1 and ∼0.07mVh−1, respectively. Hence, a low-temperature solid oxide fuel cell has been developed.