A simple approach to make the commercial solid, oxide fuel cells flexible in the use of fuels

In this paper, we propose a simple approach consisting in the use of a coating layer on a commercial SOFC in order to increase its fuel flexibility. Using the same CO2-laser-cut cell, we compared the I-V curves and impedance spectra (EIS) of four experiments. Three different ceramics (NiCu-CGO, NiFe-CGO, and NiCo-CGO) were evaluated as protective layers for cells fed with dry biogas or bioethanol, with the goal of determining which layer would be most promising. Electrochemical experiments revealed that an additional layer adds resistance to the cell, which negatively affects its performance. A slight decrease in maximum performance was observed when the coated cells were fed H2. However, power density was not significantly different from the bare cell at potentials between 0.7 and 0.8 V, which provide a trade-off between performance and voltage efficiency. Additionally, such an approach improved the effectiveness of cells in using simulated biogas and ethanol as demonstrated by I-V curves and EIS analysis. As shown in the test results, NiCo-CGO provided the highest power density of 0.56 W cm-2 at 0.6 V. However, all the cells with protective layers performed significantly better than the bare cell in the dry biofuel tests.