Performance enhancement of thin-film ceramic electrolyte fuel cell using bi-layered yttrium-doped barium zirconate

• Bi-layer thin-film electrolyte was fabricated with pulsed laser deposition method.
• Electrochemical performance was investigated at 250 °C.
• The porous layer at the cathode surface improved oxygen reduction reaction.
• Compositional and structural properties were examined with ex situ characterizations.

A thin-film yttrium-doped barium zirconate comprised of two distinct layers with different porosity was fabricated by pulsed laser deposition method for a low-temperature solid oxide fuel cell electrolyte to enhance electrode reactions and suppress electric short-circuit problem simultaneously. At 250 °C, the peak power density of bi-layer electrolyte fuel cell was ~ 2 mW/cm2, which is ~ 56% higher than that of single-layer electrolyte fuel cell due to significant reduction of cathodic activation loss. A set of materials characterizations revealed that the differences in compositions and micro-structures at the electrolytes accounts for the improved performance.