Bilayered electrolyte membranes composed of BaZr0.1Ce0.7Y0.2O3 - delta, (BZCY) and Ce0.8Sm0.2O2 - delta (SDC) were evaluated for solid oxide fuel cells (SOFCs), and the influence of the membrane architecture on the cell performance was investigated. The electrochemical testing results showed that the electron-blocking ability of BZCY layer depends on its exact location in the fuel cell. The partial internal short circuit was nearly totally eliminated for the cell with BZCY layer located at the anode side, and the corresponding cell exhibited a high open circuit voltage (OCV) of 1.0 V at 700 degrees C. In contrast, the cell with BZCY layer located at the cathode side still exhibited significant internal short-circuit behavior. The different electron-blocking ability can be ascribed to the atmosphere-dependent charge transport behavior of BZCY. The present results demonstrate that the bilayered BZCY/SDC membrane with BZCY layer located at the anode side is a promising electrolyte for highly efficient low-temperature SOFCs. Besides, the BZCY layer should be as thin as possible to achieve desirable power performance for the fuel cell. (C) 2014 Elsevier B.V. All rights reserved.