Numerical Analysis on Water Transport in Alkaline Anion Exchange Membrane Fuel Cells

Abstract

We present an isothermal, one-dimensional, steady-state model for an alkaline anion exchange membrane fuel cell (AAEMFC), in which the conducting ions (OH − ) move from the cathode to the anode. While water is produced at the anode, it is consumed at the cathode along with oxygen. The water transport in the membrane comprises water flux by the electro-osmotic drag and the diffusive water flux because of the gradient of water concentration across the membrane. The present model is validated with the experimental data in the literature and the water transport in AAEMFC is discussed. By performing numerical simulations of four cases of humidity conditions (dry or fully humidified conditions for each anode and cathode), it is reconfirmed theoretically that anode humidification is more essential to secure good AAEMFC performance. In addition, water transport through the gas diffusion layers of anode and cathode as well as the membrane is examined to provide fundamental information about water management in the AAEMFC operations.

Influences of flow direction, temperature and relative humidity on the performance of a representative anion exchange membrane fuel cell: A computational analysis

“…A high-fidelity numerical model can potentially play a complementary role to experimental investigations, and can provide detailed insights into the interactions between the electrochemical mechanism, and heat and mass transport phenomena, which play pivotal roles in water management of AEM fuel cells. One-dimensional numerical analyses conducted by Sohn et al [25] reinforced the importance of the anode humidification in order to achieve better membrane performance. Results…”

“…suggested that under dry anode condition, the overall fuel cell performance was significantly negatively affected [25]. Numerical and experimental analyses were conducted in order to evaluate the deviated concentration loss in alkaline AEM fuel cells [26].…”

Alkaline Anion-Exchange Membrane Fuel Cells: Challenges in Electrocatalysis and Interfacial Charge Transfer

“…Given the potential fuel flexibility of AAEM fuel cells, and the necessity to develop alternative nonalcoholic anodic fuel (to avoid the presence of CO 2 from complete oxidation of alcohols), the developments in the field of hydrazine oxidation are briefly reported here. Further, water management in an AAEM fuel cell MEA is critical since ineffective operating conditions is suggested to lead to anode flooding where water is generated and cathode dry-out where water is stoichiometrically consumed. , In the cathode, poor water management leads to increases in both charge transfer resistance and hydroxide-anion transport. − The subject of water management in AAEM fuel cells is beyond the scope of this review.…”

A comprehensive review on water management strategies and developments in anion exchange membrane fuel cells

“…Y.-J. Sohn et al simulation studies further revealed that anode humidification was crucial for optimum AEMFC performance [158]. They observed only marginal loss in performance when AEMFC was simulated with dry cathode and fully humidified anode while dry anode and fully humidified cathode showed a significant loss in performance.…”