Evaluation of La1.8Sr0.2NiO4+δ as cathode for intermediate temperature solid oxide fuel cells

The electrical conducting, thermal expansion and electrochemical properties of La1.8Sr0.2NiO4+delta were investigated in view of cathode utilization for intermediate temperature solid oxide fuel cells. La1.8Sr0.2NiO4+delta exhibited electrical conductivities of 96 -114 S cm(-1) at 600-800 degrees C and a thermal expansion coefficient of 12.6 x 10(-6) K-1 between 50 and 1000 degrees C. Based on a three-electrode half cell, the electrode properties of La1.8Sr0.2NiO4+delta were diagnosed using electrochemical impedance spectroscopy and chronopotentiometry techniques. Moreover, the, performance of an anode-supported single cell with La1.8Sr0.2NiO4+delta cathode was examined. Compared with La2NiO4+delta, La1.8Sr0.2NiO4+delta manifested improved electrode properties under cathodic polarization conditions while showing an analogous catalytic activity under open-circuit conditions. At 800 degrees C in air, La1.8Sr0.2NiO4+delta electrode displayed a polarization resistance of 0.41 0 cm(2) and a cathodic overpotential of 90 mV at 200 mA cm(-2). The anode-supported single cell with La1.8Sr0.2NiO4+delta cathode achieved a maximum power density of 520 mW cm(-2) at 800 degrees C in hydrogen fuel. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.