Ice Formation in Gas-Diffusion Layers [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 621.31 Generation, modification, storage, transmission of electric power
• Thông tin xuất bản: Berkeley, Calif. : Oak Ridge, Tenn. : Lawrence Berkeley National Laboratory ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2010
• Mô tả vật lý: Size: 15 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 256979
• Chủ đề: 1. 30 direct energy conversion; 2. Freeze, gas diffusion layers, fuel cells, crytallization

Tóm tắt

Under sub-freezing conditions, ice forms in the gas-diffusion layer (GDL) of a proton exchange membrane fuel cell (PEMFC) drastically reducing cell performance. Although a number of strategies exist to prevent ice formation, there is little fundamental understanding of the mechanisms of freezing within PEMFC components. Differential scanning calorimetry (DSC) is used to elucidate the effects of hydrophobicity (Teflon� loading) and water saturation on the rate of ice formation within three commercial GDLs. We find that as the Teflon� loading increases, the crystallization temperature decreases due to a change in internal ice/substrate contact angle, as well as the attainable level of water saturation. Classical nucleation theory predicts the correct trend in freezing temperature with Teflon� loading.