Effects of basic gas diffusion layer components on PEMFC performance with capillary pressure gradient. (5th August 2021)

• Record Type: Journal Article
• Authors: Sim, Jaebong; Kang, Minsoo; Min, Kyoungdoug
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 54(2021)
• Page Start: 27731
• Page End: 27748
• Publication Date: 2021-08-05
• Subjects: Polymer electrolyte membrane Fuel cell (PEMFC) -- Gas diffusion layer (GDL) -- Substrate -- Micro-porous layer (MPL) -- Capillary pressure gradient; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.05.205
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The gas diffusion layer (GDL) is composed of a substrate and a micro-porous layer (MPL), and is treated with polytetrafluoroethylene (PTFE) to promote water discharge. Additionally, the MPL mainly consists of carbon black and PTFE. In other words, the optimal design of these elements has a dominant effect on the polymer electrolyte membrane fuel cell (PEMFC) performance. For the GDL, it is crucial to prevent water flooding, and the water flux within the GDL is strongly affected by the capillary pressure gradient. In this study, the PEMFC performance was systematically investigated by varying the substrate PTFE content, MPL PTFE content, and MPL carbon loading per unit area. The effects of each experimental variable on the PEMFC performance and especially on the capillary pressure gradient were quantitatively analyzed when the GDLs were manufactured by the doctor blade manufacturing method. The experimental results indicated that as the PTFE content of the anode and cathode GDL increased, the PEMFC performance deteriorated due to the deformation of the porosity and tortuosity of the GDL. Additionally, the PEMFC performance improved as the MPL PTFE content of the cathode GDL increased at low relative humidity (RH), but the PEMFC performance tendency was reversed at high RH. Further, the MPL carbon loading of 2 mg/ cm 2 demonstrated the best performance, and the advantages and disadvantages of the MPL carbon loading were identified. In addition, the effects of each experimental variable on liquid water, water vapor, and gas permeability were investigated. Highlights: Gas diffusion layer manufactured by doctor blade manufacturing method. Effects of polytetrafluoroethylene content in the substrate and micro-porous layer. Effects of carbon loading per unit area of the micro-porous layer. Capillary pressure associated with the water flux within the gas diffusion layer. Effects of each experimental variable on capillary pressure and fluid permeability.