The effect of potassium on the properties of PrBa1−xCo2O5+δ (x = 0.00–0.10) cathodes for intermediate-temperature solid oxide fuel cells

An understanding of the relationships between the processing, compositions , and properties of perovskites is vitally important in the search for high performance cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). In this work, the properties of PrBa 1−x Co 2 O 5+δ (x = 0.00–0.10) double perovskites were modified by introducing K during synthesis, and their performances as the cathode materials for IT-SOFCs were then characterized. The addition of K resulted in a greater cation deficiency in the double perovskites, improving bulk oxygen transport. However, K addition also markedly decreased the Co ion content on the perovskites' surfaces, which significantly deteriorated the perovskites’ electrochemical performances related to the surface exchange of oxygen.