Electrochemical Characterization and Modelling of Anode and Electrolyte Supported Solid Oxide Fuel Cells

Abstract

Solid Oxide Fuel Cells (SOFCs) have emerged as an attractive alternative for efficient cogeneration of electricity and heat with reduced emissions during operation. High working temperatures result in optimized kinetics and higher efficiencies in comparison to other fuel cell types. Among different designs, Anode Supported Cells (ASCs) and Electrolyte Supported Cells are currently the most promising configurations on a commercial scale. This work analyses these two designs with a focus on electrochemical features as the main performance marker. The study was carried out using both theoretical and experimental approaches on planar single cells. A detailed test campaign at different operating conditions in terms of temperature, fuel and oxidant composition was designed. Electrochemical Impedance Spectroscopy and current-voltage (I-V) measurements were used to identify the contributions of different cell components. The electrochemical kinetics derived from the individual resistance terms was implemented in a 2D simulation tool (SIMFC-SIMulation of Fuel Cells) to obtain the detailed global cell behaviour and to understand local occurring mechanisms on anodic and cathodic cell planes. The model was validated for an anode supported cell consisting of Ni-YSZ/YSZ/LSCF-CGO and an electrolyte supported cell consisting of Ni-CGO/YSZ/LSCF-CGO, showing the possibility to tune the parameters depending on analysed cells.