Tailoring Pr0.5Sr0.5FeO3 oxides with Mn cations as a cathode for proton-conducting solid oxide fuel cells
Xin Yang, Guoqiang Li, Yue Zhou, Chongzheng Sun, Lei Bi
Abstract
The traditional Pr0.5Sr0.5FeO3 (PSF) cathode is customized with Mn cations to generate the new Pr0.5Sr0.5Fe0.9Mn0.1O3 (PSFMn) cathode for proton-conducting solid oxide fuel cells (H-SOFCs). Compared to the PSF oxide, the new PSFMn has a reduced thermal expansion, making it more compatible with electrolytes. Furthermore, Mn-doping enhances oxygen vacancy production in PSF, as revealed by experimental and first-principle calculations. More crucially, doping Mn into PSF improves proton diffusion kinetics, resulting in quicker proton diffusion and surface exchange. As a result, the H-SOFC with the PSFMn cathode achieves an output of 1446 mW cm−2 at 700 °C, but the PSF cell only achieves fuel cell performance of 1009 mW cm−2. The fundamental cause of the increased cell performance is the significantly reduced polarization resistance, implying that using the Mn-doping strategy enhances the cathode kinetics of conventional PSF cathodes for H-SOFC.