Guidelines for processing of porous barium zirconate-based ceramic electrolytes for electrochemical solid oxide cell applications

Abstract

Efficient use of barium-containing electrocatalysts for NOx decomposition in electrochemical solid oxide cells requires good chemical compatibility of these materials with the electrolyte in a temperature range 300–600 °C and imply the use of porous electrolytes allowing significant gas flows across the cell. BaZr0.85Y0.15O3 electrolyte has good chemical compatibility with Ba-containing materials and potentially appropriate level of ionic conductivity. This work is focused on guidelines for processing BaZr0.85Y0.15O3 ceramics with cellular porosity (i.e., with spherical pores and with developed gas interconnections), using emulsification of paraffin in water-based ceramic suspension. Porosity of sintered at 1500°C ceramics is practically open and varies in the range of 70-84%, with average pore sizes in the range ~3–30 µm. The type of pore size distribution is close to log-normal. Microstructure, average cell size and level of gas permeability mainly depends on surfactant content, while total porosity is mostly determined by paraffin content.