In present work, we reported an novel oxide-salt Al2O3-NaAlO2 composite, which was prepared by mixing Al2O3 and Na2CO3 two phase materials in different weight ratio, and then sintering at 1100 degrees C. The X-ray diffraction pattern, scanning-electron microscope and impedance spectra are applied to characterize the crystal structure, morphology and electrical properties of the Al2O3-NaAlO2 composite. The Al2O3-NaAlO2 composite as electrolyte membrane was sandwiched by two pieces of Ni0.8Co0.15Al0.05Li-oxide (NCAL) electrode layer to construct advanced fuel cell. Optimizing the weight ratio of Al2O3 and NaAlO2, such cell delivered an highest power density of 789 mW/cm(2) and an open circuit voltage (V-oc) of 1.13 V at 575 degrees C. The superior performance is mainly due to the excellent ion-conducting of Al2O3-NaAlO2 composites and the outstanding catalysis activity of the NCAL eletrodes. The EIS results revealed that the Al2O3-NaAlO2 composite possessed superior ionic conductivity of 0.121 S/cm at 575 degrees C. The interfacial effects between oxide-salt two phase including space-charge and structural misfit at the interface region dominated the ion transport for Al2O3-NaAlO2 composite. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.