Thermal and electrochemical properties of layered perovskite PrBaCo2−xMnxO5+δ (x = 0.1, 0.2 and 0.3) cathode materials for intermediate temperature solid oxide fuel cells

Layered perovskite PrBaCo2−xMnxO5+δ (PBCM-x, x = 0.1, 0.2 and 0.3) oxides have been synthesized and investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOCFs). The effects of Mn contents in PBCM-x materials on the crystal structure, chemical stability, thermal expansion coefficient (TEC) and electrochemical properties have been studied. XRD results have showed that the lattice parameters increase with x increasing from 0.1 to 0.3, although the crystalline structure does not change. The substitution of Co by Mn lowers the thermal expansion coefficient clearly. The average TEC decreases from 22.8 × 10−6 K−1 for PBCM-1 to 15.1 × 10−6 K−1 for PBCM-3 in the temperature range of 35-800 °C. The PBCM-x samples exhibit a semiconductor to metal transition. All the samples reach the general required electrical conductivity value of cathode material at the operating temperature range of 600-800 °C. Among the samples, PBCM-2 shows the best electrochemical performance. The single fuel cell with the configuration of PBCM-2/YSZ/Pt delivers the highest power density of 304.2 mW cm−2 at 800 °C.