Localization of CuO, NiO, and Co3O4 sintering additives in dense proton-conducting perovskite ceramics based on BaSnO3

Sintering additives have been widely employed to achieve good sinterability of barium-based proton-conducting perovskites (based on BaZrO3, BaCeO3, BaTiO3, BaHfO3, BaThO3, and BaSnO3). This is of particular importance for the fabrication of multilayered ceramic cells, in which the thin-film electrolyte layer can be primarily densified at relatively low sintering temperatures (1350–1500 °C). The introduction of sintering additives facilitates the fabrication of gas-tight ceramics; however, the precise nature of their localization and their effects on the functional properties remain uncertain and even questionable. In this study, we present a comprehensive characterization of ceramic materials based on Y-doped BaSnO3 prepared with the addition of three sintering additives (copper, cobalt, and nickel oxides) at 1 wt%. Although these introduced oxides belong to a group of compounds with similar physicochemical properties, each additive exerts a distinct influence on the microstructural and electrochemical properties of the ceramics owing to their own chemical localization features. These features are discussed in detail in the present work, providing useful information in the field of using sintering additives for the preparation of oxide ceramics for high-temperature applications.