Honeycomb-type solid oxide fuel cell using La_0.9Sr _0.1Ga_0.8Mg0.₂O₃ electrolyte for high volumetric power density

A La0.9 Sr0.1 Ga0.8 Mg0.₂O₃ (LSGM)-based honeycomb-type cell was successfully operated using single-wall and four-wall used cell structures. Power generation characteristic and internal resistance of the honeycomb cell were measured by various electrochemical techniques, including polarization, current interruption, and impedance spectrometry. The single-wall LSGM honeycomb cell shows much higher power density than that of the ZrO₂ -based cell, and the area-specific power density is achieved about 0.50 and 0.27 W cm2 at 1073 and 973 K, respectively, when the honeycomb with a 0.5 mm thick wall is used. Detail results of internal resistance analysis suggest that IR loss is the predominant potential drop of the cell. The power generations of a four-wall used (i.e., one-channel) honeycomb cell was also measured. The maximum power density of the single-channel cell is achieved at a power density of ∼1.3 W at 1073 K. Although the area-specific power density (∼0.37 W cm2) is lower than that of the single-wall cell, the estimated volumetric power density of this cell is as high as 600 WL. Furthermore, a short stack using connected two single-channel honeycombs in series was also successfully fabricated and operated, and the output power of ∼1.8 W was reached at 1073 K.