Carbon Cloth Gas Diffusion Layer Research Articles

Analysis of Gas Diffusion Layer and Flow Field Design using Neutron Radiography

A carbon cloth gas diffusion layer (GDL) displays better performance than a carbon paper GDL under humidified conditions. A straight flow field displays better performance than a serpentine flow field. To investigate these phenomena, neutron radiography was used to compare the amount of liquid water that accumulated in test fuel cells. It was found that a larger amount of water accumulated in a carbon cloth GDL than in a carbon paper GDL. From the standpoint of cell performance, the carbon cloth GDL was less influenced by the accumulated water than the carbon paper GDL. It is assumed that the broader pore distribution of a carbon cloth GDL creates oxygen diffusion paths even if water accumulates in the GDL. With a serpentine flow field, water accumulated in the corner and the gas bypassed the flow field. These phenomena are the main causes of performance deterioration with a serpentine flow field.

3620 燃料電池のガス拡散層に関する研究(G08-1 燃料電池,G08 動力エネルギーシステム)

The performance of a polymer electrolyte fuel cell (PEFC) operating on pure hydrogen and air is primarily limited by the performance of the cathode side. At high current densities, the transport of the reactant (O_2) to the catalyst layer is limited by accumulated liquid water inside the gas diffusion layer (GDL), which causes flooding. A carbon cloth GDL displays better performance than a carbon paper GDL under humidified conditions. To investigate these phenomena, neutron radiography was used to compare the amount of liquid water that accumulated in the cell with different GDL materials. It was found that a larger amount of water accumulated in a carbon cloth GDL than in a carbon paper GDL. From the standpoint of cell performance, the carbon cloth GDL was less influenced by the accumulated water than the carbon paper GDL. A carbon cloth GDL has a larger porosity distribution than a carbon paper GDL. It is assumed that carbon cloth allows O_2 transportation through the GDL due to the material's larger pores even though water accumulates in the layer.