A simple compression sealing method for planar single-cell SOFC testing

Abstract

A lab high-temperature planar solid oxide fuel cell was designed and built for developing and testing new sealing strategies. The lab cell was developed to allow easy and fast sealing and to be low cost; it was made from AISI316 stainless steel and sealed with vermiculite sheets (Thermiculite). It was applied a low compressive loading (0.2 N m) to avoid the failure of the ceramic membrane (Thermiculite). The ex-situ and in-situ experiments revealed remarkable results; the leakage rate was very low, 0.44 mL min(-1) m(-1). The electrochemical tests revealed a high stable open circuit potential of ca. 1.04 V @ 650 degrees C when hydrogen and oxygen were fed to the cell, indicating minimal crossover between the cathode and anode. The reliability of the cell design was assessed by performing several heating cycles. During the cooling and heating stages, the circuit was open while when running at the nominal temperature, 650 degrees C, a potential difference of 0.7 V was imposed for a total of 109 h. The open circuit potential remained stable during the whole experiment.