Water flow in the gas diffusion layer of PEM fuel cells
Water flow in the gas diffusion layer of PEM fuel cells
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DOI：
10.1016/j.memsci.2005.03.049
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发表时间：
2005-09-15
影响因子：
9.5
通讯作者：
Itescu, J
中科院分区：
文献类型：
--
作者：
Benziger, J;Nehlsen, J;Itescu, J
测定了聚四氟乙烯处理的聚合物电解质膜燃料电池中碳布和碳纸气体扩散介质的水流量。气体扩散层（GDL）介质是疏水性的，必须施加压力以迫使水渗透到这些材料的孔隙中。聚四氟乙烯处理使碳布和纸更具疏水性，直到施加5-10 kPa的压力以克服最大孔隙中水/聚四氟乙烯界面的表面能时，才有水流过介质。活性炭布的最大孔隙为250 μ m，东丽复写纸的最大孔隙为40 μ m。在编织碳布上施加的催化剂层中，最大孔隙约为20 μ m。增加施加的静水压力允许水通过GDL中较小的孔隙。在GDL中，水通过的空隙体积小于1%；这些小孔隙不含水，允许气体进入催化剂层。(c) 2005 Elsevier B.V.版权所有
Water flow through carbon cloth and carbon paper gas diffusion media used for polymer electrolyte membrane fuel cells treated with Teflon was measured. The gas diffusion layer (GDL) media are hydrophobic and it is necessary to apply pressure to force water to penetrate into the pores of these materials. Teflon treatments made the carbon cloth and paper more hydrophobic, no water flowed through the media until pressures of 5-10 kPa were applied to overcome the surface energy of the water/Teflon interface in the largest pores. The largest pores were similar to 250 lim in the carbon cloth and similar to 40 mu m in the Toray carbon paper. The largest pores in a catalyst layer applied to the woven carbon cloth were similar to 20 mu m. Increasing the applied hydrostatic pressure permitted water to flow through smaller pores in the GDL. Water flows through less than 1% of the void volume in the GDL; the small pores remain free of water and permit gas to get to the catalyst layer. (c) 2005 Elsevier B.V. All rights reserved.