Development of modelling and testing for analysis of degradation of Ni-YSZ anode in solid oxide fuel cells

Maillard, John Geoffrey (2018). Development of modelling and testing for analysis of degradation of Ni-YSZ anode in solid oxide fuel cells. University of Birmingham. Ph.D.

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Abstract

The ability to predict the lifetime performance of an SOFC can give guidelines for where improvements can be made in terms of production, operating parameters and cell design. Microstructural analysis ofNi-YSZ anode samples under varying steam and temperature regimes was investigated to determine trends in the anode Ni particle growth. Increasing the steam content produced larger mean Ni radii for a given temperature. Higher operating temperatures (900°C) were shown to have a significant accelerating effect on the particle size change. Further analysis of the microstructural data highlighted profiles for Ni-pore contact angle 9 values, as well as Triple Phase Boundary points and overlap length which both showed a decrease over time, highlighting differences in the rate of performance loss in the anode. Using models derived for the degradation mechanisms combined with a particle packing model, Matlab® coding was developed to predict the Ni particle growth rate and the relative change in conductivity and TPB length per unit volume. Ni particle growth rate predictions were compared to experimental results and showed good correlation. The data can be used to help design accelerated testing procedures for SOFC anodes to determine the long term performance of a given anode composition.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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