Performance of double-perovskite YBa_(0.5)Sr_(0.5)Co_(1.4)Cu_(0.6)O_(5+δ) as cathode material for intermediate-temperature solid oxide fuel cells

摘要

Double-perovskite YBa_(0.5)Sr_(0.5)Co_(1.4)Cu_(0.6)O_(5+δ) (YBSCC) is synthesized by the EDTA-citrate complexing method, and investigated as a novel cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). There are no serious reactions between YBSCC and La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ) (LSGM) except a slight peak shift. The electrical conductivities of the YBSCC sample occurs a semiconductor-metal transition at about 350℃. The thermal expansion coefficient (TEC) of the YBSCC sample is 16.4 × 10~(-6) K~(-1) between 30℃ and 850℃ in air. The lowest polarization resistance of 0.036 Ωcm~2 is achieved at 850℃. The maximum power densities of a single cell with the YBSCC cathode on a 300 um-thick LSGM electrolyte are 398 mW cm~(-2) and 272 mW cm~(-2) at 850℃ and 800℃, respectively. This study suggests that the double-perovskite YBSCC can be potential candidate for utilization as IT-SOFCs cathode.