Chemically stable BaZr_0.7Pr_0.1Y_0.2O_3-δ-BaCe_0.8Y_0.2O_3-δ bilayer electrolyte for intermediate temperature solid oxide fuel cells

Highlights: • Fabricate thin BZPY layer on BCY half-cell with pulsed laser deposition. • The bilayer electrolyte improves chemical stability against CO₂ atmosphere. • The bilayer electrolyte cell shows a good electrochemical performance. • The bilayer cell exhibits a good long-term stability under cell testing condition. - Abstract: A thin BaZr_0.7Pr_0.1Y_0.2O_3-δ (BZPY) layer (∼3.3 μm) is fabricated on anode-supported BaCe_0.8Y_0.2O_3-δ (BCY) electrolyte layer (∼28 μm) with pulsed laser deposition (PLD) technique. The BZPY/BCY bilayer electrolyte shows better chemical stability against CO₂ atmosphere compared with the BCY single electrolyte layer. The open circuit voltages (OCVs) of 0.966, 0.997 and 1.021 V with maximum power densities of 250, 177, 122 mW cm⁻² are measured in the bilayer electrolyte cell at 700, 650 and 600 °C, respectively. Besides, the BZPY/BCY bilayer electrolyte cell also exhibits a good long-term stability under the operating condition. BZPY thin film deposited with PLD technique can improve chemical stability with little effect on the electrochemical performance of proton-conducting SOFC