Improved performance of ceria-based solid oxide fuel cell using doped LaGaO3 films deposited by pulsed laser deposition

•Fabricate thin LSGM layer on SDC half-cell with pulsed laser deposition.•The thin LSGM layer blocks electronic current in SDC layer.•The bilayer cell retains the chemical, mechanical and structural integrity.•The electrochemical performance and OCVs of the cell have been improved.

A dense La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) film is fabricated using the pulsed laser deposition (PLD) technique on a Ce0.8Sm0.2O2−δ (SDC) electrolyte which is prepared using a co-pressing process on a NiO–SDC anode substrate. The LSGM/SDC bilayer electrolyte cell with Sm0.5Sr0.5CoO3−δ–Ce0.8Sm0.2O2−δ (SSC–SDC, 70:30 wt.%) cathode achieves significantly enhanced cell performance, yielding open circuit voltage (OCV) value of 0.89 V and maximum power density of 758 mW cm−2 at 700 °C. The electrical current leakage in the SDC single layer cell caused by the reduction of Ce4+ to Ce3+ in reducing environment has been eliminated by depositing the LSGM thin film as a blocking layer; besides, the reaction between NiO and LSGM can be prevented due to the dense SDC electrolyte layer. The influence of oxygen pressure and post-annealing temperature on the crystallinity, microstructure and surface roughness of the LSGM films are studied for obtaining a high quality film. Characterization analysis of the cell shows that the bilayer electrolyte deposited by the PLD technique have retained the chemical, mechanical and structural integrity of the cell.