Life prediction method of solid oxide fuel cells based on mechanistic damage and electrochemical performance degradation

Solid oxide fuel cell (SOFC) is a highly efficient energy conversion device, but its commercialization is limited by the instability of electrochemical and mechanical performance during long-term operation and high-frequency start-up cycles. This study innovatively proposes a life prediction method that combines mechanistic damage and electrochemical performance degradation. The effects of electrode reactions and microstructural degradation on the electrochemical and mechanical properties of SOFC stacks are experimentally analyzed, and a theoretical model of performance degradation is established. Combined with the multi-physics field coupling model, the evolution of stress, strain, voltage, and electrode reactions of SOFC stacks during high-temperature operation is analyzed to achieve accurate prediction of SOFC stack life. The results show that through the SOFC three-cell stack experiment, it is found that its voltage degradation is mainly caused by the increase of ohmic impedance, accounting for 60.68 % of the total degradation. This study predicts that the life of SOFC stack is 7200 h with an accuracy of 91.36 %. The accuracy of life prediction for J & uuml;lich long-term performance data exceeds 93.09 %. The analysis of mechanistic damage and electrochemical degradation mechanism provides theoretical support for SOFC life prediction and optimization design, which has important guiding significance for improving SOFC service life.