Abstract: A membrane electrode assembly may be made using a one-sided catalyst coated membrane (CCM) wherein only one catalyst layer, either the anode or the cathode, is coated directly on the ion-exchange membrane. In particular, a one-sided CCM may be used where it may not be practicable to coat both sides of the ion-exchange membrane with catalyst layers such as when PTFE is added to the anode catalyst layer to render it reversal tolerant.

Abstract: In a solid polymer fuel cell series, various circumstances can result in a fuel cell being driven into voltage reversal. For instance, cell voltage reversal can occur if that cell receives an inadequate supply of fuel. In order to pass current, reactions other than fuel oxidation can take place at the fuel cell anode, including water electrolysis and oxidation of anode components. The latter can result in significant degradation of the anode, particularly if the anode employs a carbon black supported catalyst. Such fuel cells can be made substantially more tolerant to cell reversal by using certain anodes employing both a higher catalyst loading or coverage on a corrosion-resistant support and by incorporating, in addition to the typical electrocatalyst for promoting fuel oxidation, certain unsupported catalyst compositions to promote the water electrolysis reaction.

Abstract: In preparing a fluid diffusion electrode, typical methods include applying a catalyst ink to a fluid diffusion layer, drying the catalyst ink and hot-pressing the coated fluid diffusion layer to produce a fluid diffusion electrode. In the present application, unexpected improvements in the smoothness of the resulting electrode have been observed by drying the catalyst ink during compaction. To assist with drying the catalyst layer, the compacting step may be performed at elevated temperatures. In some embodiments, a release sheet may be applied to the catalyst layer prior to compaction. In addition or alternatively, partial drying of the catalyst layer may occur prior to compaction.

Abstract: Corrosion at the cathode catalyst may be a serious problem compromising fuel cell lifetimes. However in providing for increased corrosion resistance, an expected trade-off may occur regarding fuel cell performance. TKK (Tanaka Kikenzoku Kogyo) has solved this problem by providing both increased corrosion resistance with no concomitant loss in performance with their catalysts TEC50EA10 and TEC50BA10. An alternative to the TKK catalysts is to use an admixture of platinum black and supported catalyst and in particular, an admixture comprising 30-40% by weight platinum black and 60-70% by weight supported catalyst.

Abstract: A membrane electrode assembly may be made using a one-sided catalyst coated membrane (CCM) wherein only one catalyst layer, either the anode or the cathode, is coated directly on the ion-exchange membrane. In particular, a one-sided CCM may be used where it may not be practicable to coat both sides of the ion-exchange membrane with catalyst layers such as when PTFE is added to the anode catalyst layer to render it reversal tolerant.

Abstract: In a solid polymer fuel cell series, various circumstances can result in a fuel cell being driven into voltage reversal. For instance, cell voltage reversal can occur if that cell receives an inadequate supply of fuel. In order to pass current, reactions other than fuel oxidation can take place at the fuel cell anode, including water electrolysis and oxidation of anode components. The latter can result in significant degradation of the anode, particularly if the anode employs a carbon black supported catalyst. Such fuel cells can be made substantially more tolerant to cell reversal by using certain anodes employing both a higher catalyst loading or coverage on a corrosion-resistant support and by incorporating, in addition to the typical electrocatalyst for promoting fuel oxidation, certain unsupported catalyst compositions to promote the water electrolysis reaction.

Abstract: An electrochemical fuel cell comprises at least one fluid distribution layer comprising a substantially fluid impermeable sheet material which is rendered fluid permeable at least in the active area through the non-uniform application of perforations. In some embodiments, the size of the perforations in the fluid distribution layer increases in the reactant flow direction. In other embodiments, the density of the perforations in the fluid distribution layer increases in the reactant flow direction. The fluid permeability of the fluid distribution layer may also increase from the inlet to a mid-point between the inlet and the outlet and then decrease thereafter to the outlet.