Optimization of the strength of SOFC anode supports

During operation solid oxide fuel cells are stressed by temperature gradients and various internal and external mechanical loads, which must be withstood. This work deals with the optimization of the strength of as-sintered anode supported half-cells by imposing changes to production parameters, such as powder milling and sintering temperature.

The strength was measured with the ball-on-ring method, and analyzed with a large displacement finite element model. Weibull statistics were used to describe the distribution of strengths. The influence on the Weibull strength of the many different processing parameters was found to be quantifiable in terms of cell porosity to a large extent.

The results were validated with an independent set of measurements of strength and stiffness by uniaxial tension and the impulse excitation technique, respectively. For application of the finding in relation to the SOFC technology a mathematical frame to determine the optimal porosity of a SOFC system is presented.