Micro ceramic fuel cells with multilayered yttrium-doped barium cerate and zirconate thin film electrolytes

Multi- and mono-layered thin film electrolytes based on BaCe _0.9Y_0.1O_3-δ (BCY) and BaZr _0.85Y_0.15O_3-δ (BZY) ceramics are fabricated by pulsed laser deposition (PLD) for use in micro-protonic ceramic fuel cells (micro-PCFCs), and their microstructure and fuel cell performances are investigated. Fully dense and well-crystallized BCY and BZY layers are identified in the multi- and mono-layered electrolytes, and are confirmed by microstructural analyses. Fuel cell and impedance measurements confirm that the bare BCY cells exhibit superior performance to samples with BZY capping; however, this capping does not offer any advantage in terms of operational stability. In contrast, the BCY-capped BZY cell performs better than the bare BZY cell, implying that BCY possesses more active surface kinetics. Anodic improvement is as important as cathodic modification for the intermediate-temperature operation of PCFCs. The BCY-capped BZY cell also demonstrates excellent stability, maintaining a good open circuit voltage for over 10 h.