Evaluation of solid oxide fuel cell anode based on active triple phase boundary length and tortuosity

An efficient procedure is presented for the evaluation of solid oxide fuel cell (SOFC) anode microstructure triple phase boundary length (TPBL). Triple phase boundary- the one that is common between three phases of the microstructure- has a great influence on the overall efficiency of SOFC because all electrochemical reactions of anode take place in its vicinity. Therefore, evaluation of TPBL for virtual or experimental 3D microstructures is essential for comparison purposes and the optimization processes. In this study, first, an algorithm is proposed to distinguish between percolated and non-percolated clusters for each of the phases. Then, another algorithm is used to determine the value of TPBL for all percolated clusters of three phases. Also, a procedure based on thermal and diffusion analogy is presented to assess the tortuosity of porous and solid phases. Finally for a virtual microstructure, percolated clusters, active and total TPBL and tortuosity are calculated and discussed.