Effect of Anode Gas Diffussion Layer Thickness and Porosity on the Performance of Passive Direct Methanol Fuel Cell

Abstract

Abstract Fuel cells are finding wide range of applications from small capacity cells used for portable electronic devices to large capacity stacks for automobile applications. Among the different types of fuel cells, passive Direct methanol fuel cell (DMFC) has many advantages because of its simplicity. This paper presents the effect of Anode Diffusion Layer (ADL) thickness and its porosity on the performance of a passive DMFC. A one-dimensional, non-isothermal model is developed in MATLAB environment for exploring the complex physicochemical phenomena taking place inside the passive DMFC, by considering both heat and mass transfer effects. Modeling studies have been carried out by varying the ADL thickness from 0.1 mm to 0.6 mm, and the ADL porosity from 0.3 to 0.8. The concentration distribution of methanol, water and oxygen inside the cell have been predicted and, the crossover of methanol and water across the membrane have also been estimated. It is observed that increase in thickness of the ADL decreases the methanol corss over. Further, the effect of ADL thickness and porosity on the anodic overpotential and cathodic overpotential have been estimated. It was observed that increase in ADL thickness as well as its porosity increase the overpotentials.