Stable BaCe0.5Zr0.3Y0.16Zn0.04O3-delta (BCZYZ) thin membrane was successfully prepared by in situ tape casting/co-firing method for proton-conducting solid oxide fuel cells. The starting powders were BaCO3, CeO2, ZrO2, Y2O, ZnO for electrolyte and BaCO3, CeO2, ZrO2, Y2O3, ZnO for electrolyte and BaCO3, CeO2, ZrO2, Y2O3, ZnO, NiO, graphite for anode. The anode/electrolyte bi-layers were prepared by a simple multi-layer tape casting/co-firing method. The phase characterizations and microstructures were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The anode-electrolyte bi-layers were sintered at 1450 C. The electrolytes were extremely dense with pure perovskite phase and the thickness was about 25 mu m. The anodes were porous and no obvious reaction was found between NiO and BCZYZ. With LaSr3Co15Fe15O10 (LSCF)/BCZYZ as cathode, the open current voltage and maximum power density respectively, reached 1.00V and 247 mWcm (2) at 650 C. (C) 2008 Elsevier B.V. All rights reserved.