Proton exchange membrane fuel cells (PEMFCs) have the
advantages
of high specific power, good stability, and zero emissions, making
them clean and efficient energy conversion devices. Water management
is one of the technical challenges limiting the development of PEMFC,
with liquid water blocking the pores and increasing the resistance
to mass transport. In this paper, a two-dimensional (2D) multiphase
lattice Boltzmann (LB) model is developed to obtain the liquid water
morphology within the gas diffusion layer (GDL). A 2D multicomponent
flow Lattice Boltzmann model considering electrochemical reactions
is established to investigate the effects of water saturation, activation
overpotential, and pressure difference between the inlet and outlet
gas channels on mass transport. At high water saturation, the liquid
water forms water films within the GDL preventing reactive gas transport
and water vapor are blocked near the catalyst layer making it difficult
to remove. The PEMFC can achieve higher current densities at high
activation overpotentials, but oxygen starvation will be exacerbated.
Increasing the pressure difference between the inlet and outlet gas
passages effectively increases the oxygen concentration and reduces
the water vapor concentration in the GDL. The present study improves
the understanding of the effect of GDL microstructure on mass transport
and performance of PEMFC from the mesoscopic scale.