Modelling and Prediction of Deformation during Sintering of a Metal Foam Based SOFC (EVOLVE)

Stacking of cells in a SOFC stack requires that each element be perfectly flat and deprived, as much as possible, of internal stresses while maintaining their electrochemical capabilities. The EVOLVE concept introduces a metal foam based anode in which the foam plays the role of current collector, gas diffuser and thermo-mechanical deformation buffer. In addition, it means to combine all attractive features of an Electrolyte Supported Cell (ESC), i.e. the flexibility and robustness, with the advantage of an Anode Supported Cell (ASC), the electrical power supplied, in addition to the electrochemical stability under redox cycle in temperature of a Metal Supported Cell (MSC). The use of such innovative anode architecture represents a strategy to improve performances, reliability and durability of SOFCs, along with their tolerance regarding sulphur.

Owing to the very different nature and morphology of the anode components, the deformation during sintering cannot be readily anticipated. Therefore, the global deformation of the cell was modelled and simulated by Finite Element in order to optimize the shaping process. The modelling was achieved considering a phenomenological approach of the anisotropic sintering. Calculations of the deformation include morphological and mechanical characteristics of each layer as well as the dimension of the cell to anticipate any scale effects. The thermo-mechanical parameters of each component were determined experimentally by dilatometry and three-point bending tests operated under conditions identical to those of the sintering. Results provide relevant indications on components composition and morphology, and on the sintering conditions for producing flat and stackable cells.