無電解めっき法を用いたNi-Pアモルファス合金被覆燃料電池用セパレータの作製

摘要

In this work, electro-less plating was adopted to produce a new metallic bipolar plate coated with amorphous alloy. The Ni-P amorphous alloy thin film was deposited on Al plate with a bipolar plate flow field and its corrosion resistance and contact electri­cal resistance were measured. As results, it was found that the electro-less plated Ni-P amorphous thin film showed much lower corrosion resistance than the Ni-Cr-P-B metallic glass because of its lack of Cr content and also found that the Ni-P film showed lower contact electrical resistance than the stainless steel SUS316L plate. The electricity generation tests with the single cell having the Ni-P amorphous alloy-coated bipolar plates produced in this study revealed that the single cell with the Ni-P amorphous alloy-coated bipolar plates showed excellent I-V performance as well as the cell with the carbon bipolar plates after 39th repetition. However, the I-V performance degraded gradually and was found to be much lower than that with the carbon bipolar plates after 50th repetition. Then the long time durability tests for 24 h were also conducted at the constant current density of 200 mA-cm~(-2). It was found that the cell voltage of the single cell with the Ni-P amorphous alloy-coated bipolar plates decreased gradually with time.%セパレータほ固体高分子形燃料電池（proton exchange membrane fuel cells:PEMFC）の重要な構成要素の一つである．従来，燃料電池内の腐食環境下での安定性の高さからセパレータとしてカーボン素材が用いられてきた．燃料電池のコンパクト化にはセパレータを薄くすることが不可欠であり，その結果として家庭用，自動車用ともに燃料電池の利便性を向上させることになると考えられている．しかしながら，カーボン素材は比較的脆い材料であるため，セパレータの厚さを薄くすることが困難であった．