Based on its reduced-temperature redox-stable phenomenon, the state-of-the-art perovskite oxide La0.8Sr0.2MnO3-delta (LSM) is proposed as a novel symmetrical electrode material for solid oxide fuel cells (SOFCs) at intermediate temperatures. LSM exhibits redox instability at high temperatures (>= 850 degrees C) in agreement with the literature, whereas LSM is stable in both fuel and air conditions at intermediate temperatures (<= 800 degrees C). The electrical conductivity of LSM in both air and humidified H-2 (3% H2O) exhibit a semiconductor behavior, and the maximum values are 123.8 S cm(-1) and 2.01 S cm(-1) at 800 degrees C, respectively. LSM-Gd0.2Ce0.8O2-delta (LSM-GDC) composite electrode was used to improve the electrochemical performance. The area specific resistance of LSM-based electrode decrease from 3.03 Omega cm(2) to 1.44 Omega cm(2) in air and from 10.49 Omega cm(2) to 5.19 Omega cm(2) in H-2 at 800 degrees C by adding mixed ionic-electronic conducting GDC, respectively. The electrochemical performance of symmetrical SOFCs with LSM-based electrodes are dramatically enhanced by more than 120 percent at 800 degrees C. The LSM-GDC composite electrode delivered optimum electrochemical properties with 140 h long-term stability, demonstrating its potential as both anode and cathode for symmetrical SOFCs at intermediate temperatures. (c) 2017 Elsevier Ltd. All rights reserved.