Ce0.8Sm0.2O2-delta (SDC) and LaBaCo2O5+delta (LBCO) powders with nanograins were prepared by the cationic surfactant CTAB (cetyltrimethylammonium bromide) assisting method from the inorganic precursor. XRD results reveal the good phase compatibility between fluorite (SDC) and double-perovskite (LBCO) even after sintering and operating at high temperature. The electron-conducting phase LBCO can form a percolative network in SDC-LBCO membrane when its content excesses the threshold value of 40 vol.%, as a consequence, a high electrical conductivity can be achieved with further LBCO addition. The oxygen permeation process is mainly limited by the bulk diffusion of oxygen ions in SDC-LBCO membrane when the membrane thickness is higher than 0.8 mm. The oxygen permeation flux increases with increasing temperature and decreasing membrane thickness. The maximum oxygen flux can achieve ca. 4.59 x 10(-7) mol cm(-2) s(-1) at 950 degrees C for 0.6-mm-thick composite membrane, making them be promising candidates for practical oxygen permeable devices. (C) 2011 Elsevier B.V. All rights reserved.