Modeling of the anode of a liquid-feed DMFC: Inhomogeneous compression effects and two-phase transport phenomena

The effects of compression on single and multiphase flow in a model polymer electrolyte membrane fuel cell gas diffusion layer

“…Porosity gradients may in-fact play an important role in determining the liquid water distribution and overall saturation as shown by Zhan et al [45] and more recently Wang and Chen [16] and Garcia-Salaberri et al [46]. As porosity is directly linked to the local fibre spacing the results presented in this study would also indicate that porosity grading plays an important role in directing liquid transport.…”

Effective diffusivity in partially-saturated carbon-fiber gas diffusion layers: Effect of local saturation and application to macroscopic continuum models

“…A key limitation when applying such models to PEFCs, however, is the need to input constitutive relationships to describe the transport processes involved in the above set of equations. The accuracy and reliability of macroscopic models is highly sensitive to the correlations adopted for the effective properties of the porous layers comprising the MEA [6,8,10,11]. As a result, a large body of work on the mass, electrical, and thermal transport properties of GDLs can be found in the literature (see, e.g., [12] and references therein).…”

Effect of electrode variable contact angle on the performance and transport characteristics of passive direct methanol fuel cells

“…Greek letters a kinetic transfer coefficient g reaction order d thickness, m ε porosity h voltage loss, V q contact angle, l water content in ionomer m dynamic viscosity, kg m À1 s À1 r density, kg m À3 k ionic conductivity of membrane, U À1 m À1 s surface tension coefficient, N m À1 s s electric conductivity, U À1 m À1 Ф potential, V i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y x x x ( 2 0 1 5 ) 1 e2 0 evaluate the effects of the various operating and design parameters on the transport characteristics and performance, for example, the methanol feeding concentration [24e26], operating temperature [27,28], catalyst properties of anode and cathode [29] operating current density [28,30], methanol crossover [25,28], water transport [31e33], geometric dimensions [34,35] and electrochemical impedance spectra [36] were all considered. In addition, mathematical models were developed to study the transient operation as well [28,30,37].…”