Performance of an anode-supported tubular solid oxide fuel cells stack with two single cells connected by a co-sintered ceramic interconnector

Two anode-supported tubular solid oxide fuel cells (SOFCs) have been connected by a co-sintered ceramic interconnector to form a stack. This novel bilayered ceramic interconnector consists of La-doped SrTiO3 (La0.4Sr0.6TiO3) and Sr-doped lanthanum manganite (La0.8Sr0.2MnO3), which is fabricated by co-sintering with green anode at 1380 °C for 3 h. La0.4Sr0.6TiO3 (LST) acts as a barrier avoiding the outward diffusion of H2 to the cathode; while La0.8Sr0.2MnO3 (LSM) prevents O2 from diffusing inward to the anode. The compatibility of LST and LSM, as well as their microstructure which co-sintered with anode are both studied. The resistances between anode and LST/LSM interconnector at different temperatures are determined by AC impedance spectra. The results have showed that the bilayered LST/LSM is adequate for SOFC interconnector application. The active area is 2 cm2 for interconnector and 16 cm2 for the total cathode of the stack. When operating at 900 °C, 850 °C, 800 °C with H2 as fuel and O2 as oxidant, the maximum power density of the stack are 353 mW cm−2, 285 mW cm−2 and 237.5 mW cm−2, respectively, i.e., approximately 80% power output efficiency can be achieved compared with the total of the two single cells.