Abstract: A microporous layer sheet for a fuel cell according to the present invention includes at least two microporous layers, which are stacked on a gas diffusion layer substrate, and contain a carbon material and a binder. Then, the microporous layer sheet for a fuel cell is characterized in that a content of the binder in the microporous layer as a first layer located on the gas diffusion layer substrate side is smaller than contents of the binder in the microporous layers other than the first layer. The microporous layer sheet for a fuel cell, which is as described above, can ensure gas permeability and drainage performance without lowering strength. Hence, the microporous layer sheet for a fuel cell, which is as described above, can contribute to performance enhancement of a polymer electrolyte fuel cell by application thereof to a gas diffusion layer.

Abstract: A gas diffusion layer (30) for a fuel cell includes: a gas diffusion layer substrate (31); and a microporous layer (32) containing a granular carbon material and scale-like graphite and formed on the gas diffusion layer substrate (31). The microporous layer (32) includes a concentrated region (32a) of the scale-like graphite that is formed into a belt-like shape extending in a direction approximately parallel to a junction surface (31a) between the microporous layer (32) and the gas diffusion layer substrate (31). Accordingly, both resistance to dry-out and resistance to flooding, which are generally in a trade-off relationship, in the gas diffusion layer can be ensured so as to contribute to an increase in performance of a polymer electrolyte fuel cell.

Abstract: An electrolyte membrane-electrode assembly comprises a polymer electrolyte membrane; a cathode catalyst layer and a cathode gas diffusion layer including a cathode micro porous layer and a cathode gas diffusion layer substrate, arranged in order on one side of the polymer electrolyte membrane, and an anode catalyst layer and an anode gas diffusion layer including an anode micro porous layer and an anode gas diffusion layer substrate, arranged in order on the other side of the polymer electrolyte membrane. A relative gas diffusion coefficient of the anode micro porous layer is smaller than a relative gas diffusion coefficient of the cathode micro porous layer by an amount equal to or greater than 0.05[?].

Abstract: A gas diffusion layer for a fuel cell includes a gas diffusion layer substrate and a microporous layer formed on the surface of the gas diffusion layer substrate. The microporous layer is formed into a sheet-like shape including a binder and a carbon material containing at least scale-like graphite, and the sheet-like microporous layer is attached to the gas diffusion layer substrate. The gas diffusion layer for a fuel cell having such a configuration, prevents the components included in the microporous layer from entering the gas diffusion layer substrate, so as to ensure gas permeability. In addition, the scale-like graphite contained in the microporous layer as an electrically conductive material improves electrical conductivity and gas permeability. Accordingly, the gas diffusion layer contributes to an improvement in performance of a polymer electrolyte fuel cell.

Abstract: An electrolyte membrane-electrode assembly comprises a polymer electrolyte membrane; a cathode catalyst layer and a cathode gas diffusion layer including a cathode micro porous layer and a cathode gas diffusion layer substrate, arranged in order on one side of the polymer electrolyte membrane, and an anode catalyst layer and an anode gas diffusion layer including an anode micro porous layer and an anode gas diffusion layer substrate, arranged in order on the other side of the polymer electrolyte membrane. A relative gas diffusion coefficient of the anode micro porous layer is smaller than a relative gas diffusion coefficient of the cathode micro porous layer by an amount equal to or greater than 0.05[?].

Abstract: A gas diffusion layer (30) for a fuel cell includes: a gas diffusion layer substrate (31); and a microporous layer (32) containing a granular carbon material and scale-like graphite and formed on the gas diffusion layer substrate (31). The microporous layer (32) includes a concentrated region (32a) of the scale-like graphite that is formed into a belt-like shape extending in a direction approximately parallel to a junction surface (31a) between the microporous layer (32) and the gas diffusion layer substrate (31). Accordingly, both resistance to dry-out and resistance to flooding, which are generally in a trade-off relationship, in the gas diffusion layer can be ensured so as to contribute to an increase in performance of a polymer electrolyte fuel cell.

Abstract: A microporous layer sheet for a fuel cell according to the present invention includes at least two microporous layers, which are stacked on a gas diffusion layer substrate, and contain a carbon material and a binder. Then, the microporous layer sheet for a fuel cell is characterized in that a content of the binder in the microporous layer as a first layer located on the gas diffusion layer substrate side is smaller than contents of the binder in the microporous layers other than the first layer. The microporous layer sheet for a fuel cell, which is as described above, can ensure gas permeability and drainage performance without lowering strength. Hence, the microporous layer sheet for a fuel cell, which is as described above, can contribute to performance enhancement of a polymer electrolyte fuel cell by application thereof to a gas diffusion layer.

Abstract: A gas diffusion layer for a fuel cell includes a gas diffusion layer substrate and a microporous layer formed on the surface of the gas diffusion layer substrate. The microporous layer is formed into a sheet-like shape including a binder and a carbon material containing at least scale-like graphite, and the sheet-like microporous layer is attached to the gas diffusion layer substrate. The gas diffusion layer for a fuel cell having such a configuration, prevents the components included in the microporous layer from entering the gas diffusion layer substrate, so as to ensure gas permeability. In addition, the scale-like graphite contained in the microporous layer as an electrically conductive material improves electrical conductivity and gas permeability. Accordingly, the gas diffusion layer contributes to an improvement in performance of a polymer electrolyte fuel cell.

Abstract: To provide a means of further improving the cell's start-up capability (below-freezing-point-start-up capability) in a low temperature environment in the gas diffusion layer used in the fuel cell. It is a gas diffusion layer for fuel cell having a pore volume of micropores of 2.0×10?4 cm3/cm2 or higher.

Abstract: An electrolyte membrane-electrode assembly of the present invention includes: an electrolyte membrane; an anode-side electrode including an anode-side catalyst layer disposed on one side of the electrolyte membrane and an anode-side gas diffusion layer formed on the anode-side catalyst layer beyond a surface-direction end of the anode-side catalyst layer; an anode-side adhesive layer disposed on at least a part of a periphery of the anode-side catalyst layer; and an anode-side gasket layer disposed in contact with the anode-side adhesive layer, wherein a surface-direction inner end of the anode-side adhesive lay is located inside beyond a surface-direction inner end of the anode-side gasket layer, and a part of the anode-side adhesive layer is located to overlap with a part of the anode-side gas diffusion layer with respect to a thickness direction. Further, on the other side of the electrolyte membrane, cathode-side respective layers having the same constructions as above are disposed.

Abstract: An electrolyte membrane-electrode assembly of the present invention includes: an electrolyte membrane; an anode-side electrode including an anode-side catalyst layer disposed on one side of the electrolyte membrane and an anode-side gas diffusion layer formed on the anode-side catalyst layer beyond a surface-direction end of the anode-side catalyst layer; an anode-side adhesive layer disposed on at least a part of a periphery of the anode-side catalyst layer; and an anode-side gasket layer disposed in contact with the anode-side adhesive layer, wherein a surface-direction inner end of the anode-side adhesive lay is located inside beyond a surface-direction inner end of the anode-side gasket layer, and a part of the anode-side adhesive layer is located to overlap with a part of the anode-side gas diffusion layer with respect to a thickness direction. Further, on the other side of the electrolyte membrane, a cathode-side respective layers having the same constructions as above are disposed.