A conceptual, mathematical and quantitative reassessment of the Thin-film Flooded Agglomerate Model for air cathodes

Design, fabrication, scale-up, operation and degradation analysis of GDEs electrode are complex operations, requiring a precise knowledge-base and quantitative guidelines. Mathematical tools are strongly needed for this purpose, but often they exhibit conceptual, formal and computational complexities that -in practice -are manageable only by modelling experts. Consequently, models are, in fact, not sufficiently exploited to support systematically metal-air battery research, development and control, as they would have the potentialities to do. Sometimes, experiments are essentially used just to validate models, rather than using models to direct experimental work. In order to enable the concrete integration of mathematical modelling with experimental work on GDEs for ORR, in this paper we present a conceptual restatement of a state-of-the-art model for ORR GDEs, in view of physicochemical and mathematical perspicuity. In addition, we provide a simplified analytical solution, that enables straightforward and physically transparent parametric analysis, and a detailed description of the numerical solution of the full problem.