Three-Dimensional Modeling and Experimental Study of a High Temperature PBI-Based PEM Fuel Cell

Abstract

This paper investigates the performance of a high temperature proton exchange membrane ͑PEM͒ fuel cell. Both experimental work and numerical simulation are conducted. The high temperature proton exchange membrane is based on polybenzimidazole ͑PBI͒ doped with phosphoric acid. A single cell with triple serpentine flow channels was operated at steady state at various levels of temperature, pressure, and air stoichiometry. A three-dimensional model was used to simulate the cell performance, and polarization curves were used to validate the experimental values. The theoretical model accurately predicts the experimental results. A sound knowledge of the impact of various variables at various levels of the cell operation is necessary for unraveling the parametric influence and can prove extremely useful for optimizing the cell operation.

Effects of geometry/dimensions of gas flow channels and operating conditions on high-temperature PEM fuel cells

“…Low-temperature PEM fuel cells have a low operating temperature below 100°C, whereas high-temperature PEM fuel cells work at temperatures above 100°C, typically in the range from 120 to 180°C [2]. The heat and mass transport phenomena and material properties of low-temperature and high-temperature PEM fuel cells have some significant differences.…”

Effects of composite porous gas-diffusion layers on performance of proton exchange membrane fuel cell

“…The rate of hydrogen consumption is given by (15) Similarly, the rate of oxygen consumption at the cathode-side catalyst layer is (16) The produced water can be described as a source term based on the local current density of the cathode: (17) The local current density can be calculated according to Butler-Volmer equation: (18) (19) α a and α c are the anode and cathode charge transfer coefficients respectively; and γ is the empirical concentration parameter. The activation over potential is calculated as (20) The ohmic and protonic overpotentials, the main causes of the performance drop in a fuel cell at medium current density, can be calculated by the following equations: (21) (22) where l g and l m represent the thicknesses of the GDL and membrane, …”

Dynamic modeling and experimental investigation of a high temperature PEM fuel cell stack

“…Increasing temperature tends to improve the performance of the fuel cell as it overcomes activation polarization, but higher temperatures also accelerate degradation processes, as presented in [18,19]. In parallel with the experimental data, models have been developed to study the phenomena of interest such as the influence of the charge double layer [20], or the distribution of current and gases in the flow channels [21]. These models make use of computational fluid dynamics to gain insights into the performance of the fuel cell.…”