Effect of Cu doping on the electrochemical properties and structural phases of La0.8Sr0.2Mn1- xCuxO3 (0 ≤ x ≤ 0.2) at elevated temperature

The electrochemical properties of La0.8Sr0.2Mn1 - xCuxO3 (0 <= x <= 0.2)-Gd0.2Ce0.8O2 - delta (GDC) composite cathodes are determined in the intermediate-temperature range (600-850 degrees C), and their cathode performance is analyzed in the context of their phase transition behavior at elevated temperatures. The addition of Cu to LSM forces Mn3+ to Mn4+, thereby increasing the Mn4+ concentration with increasing Cu doping. The increased Mn4+ concentration increases the cubic phase fraction, and thus enhances the low-temperature performance of the LSM cathode. The La0.8Sr0.2Mn0.8Cu0.2O3-GDC yields the greatest low-temperature cubic phase fraction and shows the smallest area specific resistance (0.49 Omega cm(2) at 750 degrees C) of the compositions tested. (C) 2014 Elsevier B.V. All rights reserved.