Characterization of one-step co-fired BaZr0.8Y0.2O3-δ-La2Ce2O7 composite electrolyte for low-temperature solid oxide fuel cells

Abstract

Doped BaZrO3 has outstanding stability and proton conductivity, and doped-ceria La2Ce2O7(LCO) has mixed conductivities of free-electron, oxygen-ion and proton, which are both potential electrolyte materials. Herein, one-step-co-fired BaZr0.8Y0.2O3-δ(BZY)-LCO composite electrolytes are prepared and characterized to give play to their respective advantages and avoid their shortcomings for low-temperature solid oxide fuel cells (LT-SOFCs). As for different components of BZY-LCO, the sintering activity increases with the increase of LCO content, however, the corresponding open circuit voltage decreases. Interestingly, the 30 %mol BZY-70 %mol LCO (3BZY-LCO) shows the best overall performance as functions of sintering activity, total conductivity, cell performance. As for the anode supported single cells, the maximum power density of 3BZY-LCO electrolyte can reach 0.581 W cm−2 at 750 °C using humidified hydrogen (3% H2O) as fuel. Preliminary experiment results suggest that the strategy of composite electrolyte can make up for the shortcomings of doped BaZrO3 and doped-ceria to a certain extent for LT-SOFCs.