A Novel Preparation Route to Optimised Core-Shell Electrolyte Materials for Proton Ceramic Fuel Cells

摘要

We have developed an original method to prepare mixed nanoparticulate yttrium doped barium cerate and zirconate (BCY, BZY) with a core-shell structure. The cerate and zirconate were each doped with 10 % yttrium (BCY10, BZY10). A methodology based on the hydrogelation of acrylates was used to enrobe BZY10 nanopowders by a thin coating of BCY10. This procedure leads to a novel material in which the grain boundary properties of BZY10 are reduced and the chemical stability of BCY10 is improved. Dense ceramics (≥97%) were obtained by sintering the pellets at 1300 °C for 10 h. At this temperature, the two phases BCY10 and BZY10 are identified by X-ray diffraction. The proton conductivity and the chemical stability of core-shell structure materials were compared with those of (non-core shell) BCY10 and BZY10. Total conductivities were measured by impedance spectroscopy under wet nitrogen in the range 300-600 °C . A high total conductivity (5 ×10~(-3) S/cm at 500 °C ) and improved stability against carb onation was observed for the core-shell materials. These results indicate that core-shell nanopowders could be a promising electrolyte material for a proton ceramic fuel cell operating at intermediate temperatures.^