The effect of calcium on the properties of SmBa1-xCaxCoCuO5+δ as a cathode material for intermediate-temperature solid oxide fuel cells

The effect of calcium on the properties of SmBa1-xCaxCoCuO5+delta (x = 0.0-0.3) as a cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs) is evaluated systematically. Samples exhibit a highly crystalline double perovskite phase, and their cell volumes decrease as x is changed from 0.0 to 0.3. The oxygen content and average thermal expansion coefficient (TEC) of SmBa1-xCaxCoCuO5+delta decreases as the calcium content increased. An average TEC of as low as 15.3 x 10(-6) C-1 is obtained for SmBa0.7Ca0.3CoCuO5+delta. The area specific resistances at 700 degrees C decrease by approximately 50% when the calcium content is increased from x = 0.0 (0.173 ohm cm(2)) to x = 0.3 (0.086 ohm cm(2)). The maximum power densities of SmBa1-xCaxCoCuO5+delta-based single cells at 800 C increase from 635 mW cm(-2) (x = 0.0) to 939 mW cm(-2) (x = 0.3). 2016 (C) Elsevier Ltd. All rights reserved.