Ba1−xSrxCe0.8−yZryY0.2O3−δ protonic electrolytes synthesized by hetero-composition-exchange method for solid oxide fuel cells

This study reports the synthesis of proton-conducting Ba0.8Sr0.2Ce0.6Zr0.2Y0.2O3−δ oxides by using a combination of the sol-gel process and hetero-composition-exchange technique. The experimental results show that the sintered Ba0.8Sr0.2Ce0.6Zr0.2Y0.2O3−δ pellet synthesized by the hetero-composition-exchange method exhibits excellent sinterability, good relatively density, and high protonic conduction. Furthermore, the Pt/electrolyte/Pt single cell with such an electrolyte shows a significantly higher maximum power density as compared to those oxides prepared from conventional sol-gel powders. Based on the experimental results, we attempt to explain the improvement mechanism in terms of as-calcined particle characteristics and proton hopping distance. This work shows that the Ba1−xSrxCe0.8−yZryY0.2O3−δ oxides synthesized by the sol-gel combined with hetero-composition-exchange method would be a promising electrolyte for H+-SOFC applications. More importantly, this new fabrication approach could be applied to other similar perovskite-type electrolyte systems.