Further optimization of the properties of Pr0.6Sr0.4Fe0.9W0.1O3-δ by Cu-doping as symmetric electrodes for solid oxide fuel cells

Copper-doped Pr0.6Sr0.4Fe0.8Cu0.1W0.1O3-δ (PSFCuW) as a symmetric electrode material is investigated for La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM)-based symmetric solid oxide fuel cells (SSOFCs). The effect of Cu-doping on stability and mechanism of hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) is investigated and analyzed. Fe partially replaced by Cu on the B-site could also keep the phase structure stable after treatment under reducing conditions and improve the electrical conductivity, which reaches 30.3 and 0.78-1 under oxidizing and reducing conditions at 800 oC, respectively. The distribution of relaxation times (DRT) indicates that the rate-limiting step processes under oxidation conditions are oxygen adsorption and diffusion, while hydrogen adsorption and charge transfer have important influences on the rate-limiting step under reduced atmospheres, respectively. Finally, the LSGM-supported SSOFC (PSFCuW|LSGM|PSFCuW) shows excellent stability and reversibility. These results imply that PSFCuW is an up-to-coming symmetric electrode material for application in SSOFCs. •Cu-doped PSFW as symmetric electrodes are investigated for SSOFCs systematically.•Mechanisms of HOR and ORR are analyzed using distribution of relaxation times.•The symmetric electrodes exhibit different electro-catalytic ability.•The cell with different symmetric electrodes shows considerable stability and reversibility.