Microstructure Analysis Tools for Quantification of Key Structural Properties of Fuel Cell Materials

Abstract

The objective of this work is to develop advanced microstructure analysis tools for direct quantification of the key structural properties of complex fuel cell materials. Computationally efficient algorithms have been developed to extract the key structural parameters from measured microstructure datasets of these materials. In addition to determination of the traditional structural measures (e.g., porosity, surface area, phase connectivity), two novel microstructure analysis techniques are introduced for the quantification of pore size and tortuosity distributions. For initial demonstration purposes, the methods developed are applied to a digitally reconstructed sample of the micro-porous layer (MPL) of a polymer electrolyte fuel cell (PEFC). The results produced from these analyses are compared to previously reported experimental and model-derived values where applicable.

Microstructure design using graphs

“…We note that graphs have been used in many material science models ranging from molecular structure 15,16 to grain boundaries 17,18 and porous microstructure. 19 Discretized microstructure is represented as a labeled, weighted, undirected graph G = (V,E,W,L) ( Fig. 1a).…”

“…In general, most transport and reaction characteristics that depend on the underlying morphology can be recast as graph measures. 19,20 Given graph-based representation of the microstructure, a surrogate model of material properties is constructed directly on the graph-based representation. Traditionally, there have been a spectrum of approaches for constructing a mapping from a given microstructure to its associated device performance indicator.…”