Investigation of the Fe doping effect on the B-site of the layered perovskite PrBa0.8Ca0.2Co2O5+delta for a promising cathode material of the intermediate-temperature solid oxide fuel cells

Abstract

Layered perovskites can be considered as promising cathode materials for intermediate temperature solid oxide fuel cell because of their fast oxygen kinetics compared to simple perovskites. Among them, the cobalt-based layered perovskites are considered as very promising cathode materials due to its high conductivity and fast oxygen kinetics, but they are unstable under operating condition. Doping other transition metal such as Fe, Mn, Cu, and Ni can be considered to solve the instability of the cobalt-based layered perovskites. In this paper, we investigated Fe doped cobalt-based layered perovskite, PrBa0.8Ca0.2CO2-xFexO5+delta (x = 0, 0.5, and 1.0), as prospective cathode materials in terms of their crystal structures, thermal expansion behavior, electro- and electro-chemical properties. The PrBa0.8Ca0.2Co1.5Fe0.5O5+delta shows improved maximum power density of 1.89 W cm(-2) and polarization resistance of 0.080 Omega cm(2) at 600 degrees C as compared with un-doped PrBa0.8Ca0.2CO2O5+delta while maintaining suppressed thermal expansion. Based on these results, PrBa0.8Ca0.2CO1.5Fe0.5O5+delta can be considered as a promising cathode material for intermediate-temperature solid oxide fuel cell. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.