An Efficient Electron-Blocking Interlayer Induced by Metal Ion Diffusion for SOFC Based on Y-Doped Ceria Electrolyte.

To suppress the internal electronic leakage at ceria-based electrolyte, a novel electron-blocking layer consisting of doped BaCe _0.8 Y _0.2 O _3-δ was fabricated in situ at the interface of Ba-containing anode and Y-doped ceria electrolyte. The anode-supported full cell based on Y _0.2 Ce _0.8 O _1.9 (YDC20) electrolyte presents a remarkable peak power density of 814 mW/cm ² as well as an open-circuit voltage of 1.0 V at 650 °C, which are much higher than those of the cells with Gd _0.1 Ce _0.9 O _1.95 (GDC10) electrolyte (453 mW/cm ² at 650 °C) and BaCe _0.8 Y _0.2 O _3-δ |Y _0.2 Ce _0.8 O _1.9 (BCY|YDC20) bilayered electrolyte (419 mW/cm ² at 650 °C). The efficient promotion of the electron-blocking interlayer with high oxygen ionic conductivity is considered as the main reason for the improved performance of YDC20-based solid oxide fuel cell. The composition and the microstructure of the electron-blocking interlayer are further analyzed by scanning electron microscope and transmission electron microscope characterizations.