Validating the efficiency of γ-Al2O3/La0.6Sr0.4Co0.2Fe0.8O3-δ double-layer electrolyte for low temperature solid oxide fuel cell

Perovskite La0.6Sr0.4Co0.2Fe0.8O3+δ (LSCF) as a promising cathode material possessed overwhelming electronic conduction along with certain ionic conductivity. Its strong electron conduction capability hinder the application of pure-phase LSCF as electrolyte in semiconductor membrane fuel cell (SMFC). In order to constrain the electron transport and take advantage of the decent ion conduction of LSCF, a thin layer of γ-Al2O3 with insulating property was added as an electron barrier layer and combine with LSCF to form a two-layer structure electrolyte. Through adjusting the weight ratio of LSCF/γ-Al2O3 to optimize the thickness of double layers, an open circuit voltage of 0.98 V and a maximum power density of 690 mW/cm2 was received at 550 °C. At the same time, SEM, EIS and other characterization technology had proven that the LSCF/γ-Al2O3 bi-layer electrolyte can work efficiently at low temperature. The advantage of this work is the application of double-layer (γ-Al2O3/LSCF) structure electrolyte to instead of mixed material electrolyte in low-temperature solid oxide fuel cells. Structural innovation and the using of insulating materials provided clues for the further development of SMFC.