Structural and electrochemical property evolutions of perovskite SOFC anodes: Role of fuel atmosphere in (La_(0.4)Sr_(0.6))_(1-x)Co_(0.2)Fe_(0.7)Nb_(0.1)O_(3-δ)

摘要

The in-situ precipitated nano metal particle-perovskite anodes show promising application prospects in Solid Oxide Fuel Cells. Previously reports mainly show new exsolved material, but barely focus on their practical application concerns. Herein, the structural and electrochemical properties evolution of (La0.4Sr0.6)(1-x)Co0.2Fe0.7Nb0.1O3-delta (LSCFN, x = 0, 0.05, 0.1) versus varied anode fuel atmospheres are presented. Results show that perovskite-type LSCFN anodes are fully reduced to K2NiF4 structure in dry H-2 at 850 degrees C, but maintain to be ABO(3) structure with minor structure change under water containing H-2. The exsolved Co1-xFex phases are observed under both conditions, but with much higher Fe content under dry H-2. The Electrochemical Impedance Spectra shows that LSCFN anodes are more sensitive to p(H2) change under humidified fuels than dry conditions. Single cells with (La0.4Sr0.6)(0.9)Co0.2Fe0.7Nb0.1O3-delta anode show promising performance with maximum power densities of 1.2 and 0.95 W/cm(2) under dry and wet H-2 at 850 degrees C, respectively. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.