Cell, Stack and System Modelling

This chapter discusses solid oxide fuel cells (SOFC) modeling, primarily from the perspective of cells and stacks. Modeling of SOFCs is advancing at a rapid rate, facilitating quick predictions of SOFC performance at a number of levels, and aiding the design of SOFC systems. Macroscopic flow and thermal models are the best known models and have followed from straightforward chemical engineering principles of mass and energy balance. At the nanoscale of atoms and molecules, predictions of material behavior and of interface interactions are also becoming possible. Most significant advances are now taking place in the understanding of complex composite structures of electrodes and three phase boundaries. Ultimately, these should lead to predictions of cell behavior, which, at present, are measured empirically and inserted into stack models. Stack modeling has advanced to the point where acceptable start-up rates can be predicted and where overall performance can be optimized. The integration of these stacks into complete systems can also be predicted with some precision, leading to new design possibilities for hybrid SOFCs.