Investigation of contact pressure distribution on gas diffusion layer of fuel cell with pneumatic endplate

Abstract

Polymer electrolyte membrane fuel cell is a promising energy conversion device because of its high energy density, high efficiency and low emissions. Contact pressure on gas diffusion layers plays an important role in the performance improvement of polymer electrolyte membrane fuel cells by optimizing the ohmic and concentration losses. In this paper, geometric parameters of a pneumatic clamping system are optimized using a central composite design method and finite element simulations to obtain the most uniform contact pressure distribution on gas diffusion layers. The experimental data obtained by the pressure mapping system have been employed to validate the results of the optimized clamping system. The embedded pressure measurement films are placed in the designed polymer electrolyte membrane fuel cell with an active area of 400 cm2. The results reveal that the maximum difference between numerical and experimental results is less than 8%. Moreover, the contact pressure distributions over the gas diffusion layer for the clamping systems of pneumatic and conventional endplates are compared. The results demonstrate that the weight and efficiency of the clamping system with optimized pneumatic endplate is significantly better than the clamping system with conventional endplates.