Infrared Thermography and Thermoelectrical Study of a Solid Oxide Fuel Cell

The current interest in power generation industry with more efficient and clean, and more environmentally friendly ways has attracted the research and development in solid oxide fuel cell (SOFC). In SOFC, the chemical energy is converted into electric energy and heat as the by-product. In order to make a thermally self-sustained fuel cell stack, the understanding and management of the heat generation and electric power is a critical issue. Infrared thermography provides a non-destructive way to measure surface temperature. It was used to measure the instantaneous cathode surface temperature response to the current in an operating electrolyte supported planar solid oxide fuel cell (LSCF-6ScSZ-NiO). A numerical model was built to study the coupled electric current and temperature relation by incorporating the temperature dependent material properties, i.e. ohmic resistance and activation resistance, as global functions in the model. The thermal and electric fields were solved simultaneously. The measured and the predicted results agree to each other reasonably well. The cathode polarization overpotential tends to increase with the current at low current densities, but the simulated polarization-current curve exhibited a decreased slope under higher current densities that is ascribed to the local temperature increases due to the high current energy losses.