Effect of Microstructural Damage on the Thermomechanical Properties of Electrodes in Proton Exchange Membrane Fuel Cells.

Abstract

Advanced functional materials composed of multiple nanoscale phases, including pores and interfaces, have been extensively applied in the fields of new energy, architecture, and aerospace. However, insufficient knowledge of the thermomechanical properties resulting from material failures, such as interfacial delamination and porosity deformations, which limit the durability and lifetime of these materials, has hindered their further application, demanding a deeper understanding of microstructural changes. Based on the fuel cell electrode, we explore a multiscale prediction model that correlates the atomic interactions between interfaces with a microscopic thermomechanical model to illuminate the effects of interface binding characteristics on the materials' mechanical response and heat conduction mechanisms. Compared with experimental measurements and theoretical calculations at the macroscopic scale, our model excels in predicting the initiation and propagation of interfacial debonding and the thermal conductivity of the electrode, with the resistance factors for the interface, pores, and cracks taken into consideration. This work provides guidance for designing robust electrodes resistant to thermomechanical failure and serves as a reference method for predicting damage in heterogeneous porous materials.