Micro-tubular SOFC systems - Fabrication, testing and analysis of micro-tubular SOFC

Abstract

This report summarizes the testing and analysis results on the electrochemical evaluation of a micro-tubular SOFC supported by a micro anode tube, composed of Sc2O3-doped ZrO2 (ScSZ) and NiO mixture. The cell was fabricated through a co-sintering of the ScSZ electrolyte and NiO-ScSZ anode support, and then a La0.6Sr0.4Co0.2Fe0.8O3-x-Ce0.9Gd0.1O1.95 cathode layer was deposited on the electrolyte film. Evaluation was conducted using a potentio/galvanostat and impedance analyzer under a humidified hydrogen flow. Power densities at 0.7 V were 29.4, 154.3 and 382.1 mW/cm(2) at 500, 550 and 600 degrees C, respectively. Impedance analyses showed that with increasing operation temperature, ohmic and electrode activation resistances (semicircle at higher frequency region) became decreased, while gas diffusion resistance (semicircle at lower frequency region) depended weakly upon the temperature above 550 degrees C.