High performance and stability of PrBa0.5Sr0.5Fe2O5+δ symmetrical electrode for intermediate temperature solid oxide fuel cells

Abstract

Compared to traditional solid oxide fuel cells (SOFCs), symmetrical solid oxide fuel cells (SSOFCs) have the advantages of simple assembly, low cost, and stable redox processes. In this study, Sr-doped PrBa0.5Sr0.5Fe2O5+δ (PBSF) oxide was prepared and characterized as a symmetrical electrode for hydrocarbon solid oxide fuel cells. PBSF has good structural stability and chemical compatibility with the La0.8Sr0.2Ga0.83Mg0.17O3−δ(LSGM) electrolyte. Sr-doped PrBa0.5Sr0.5Fe2O5+δ sample improved conductivity compared to the parent PrBaFe2O5+δ. At 700 °C, the polarization resistance (Rp) of the PBSF was 0.052 and 1.57 Ωcm2 in air and dry hydrogen, respectively. At 800 °C, the maximum power density of PBSF/LSGM/PBSF fuel cell with 0.3 mm-thick LSGM electrolyte support reached 791 mWcm−2 and 535.8 mWcm−2 using 3% humidified H2 and propane fuel, respectively. In addition, the PBSF symmetrical electrode showed good electrochemical performance and stability for the CO2 electrolysis of SOECs at medium temperatures. Therefore, PBSF may be a potential symmetrical electrode material for SOFCs.