An experimental investigation of three-dimensional mechanical characteristics of gas diffusion layers in proton electrolyte membrane fuel cells

In this study, three-dimensional (3D) orthotropic mechanical properties of a commercial gas diffusion layer (GDL) are experimentally investigated. Although GDL is an important 3D structural membrane in proton electrolyte membrane fuel cells (PEMFCs), most papers have merely considered its in-plane linear isotropic characteristics due to the lack of 3D anisotropic mechanical performance investigation. In real operating PEMFCs, GDL is nonlinear orthotropic composite and its mechanical characteristics affect the overall performance of PEMFCs, seriously and directly. In this research, as considering GDL’s valid configuration in PEMFCs, mechanical tests such as compression test, tension test, and shear test are conducted to study its 3D mechanical behavior. Test results present that the GDL behaves in an orthotropic and nonlinear manner. In addition, microstructures of the GDL are observed through scanning electron microscope (SEM) images, to explain its different kinds of mechanical failure performance.