The present invention provides a catalysed decal transfer substrate comprising a decal transfer substrate, an electrocatalyst later, and a layer D between the decal transfer substrate and the electrocatalyst layer which comprises an ion-conducting polymer and a carbon material. The layer D is configured such that, upon transfer of the electrocatalyst layer to a surface, at least a portion of the layer D remains attached to and is transferred with the electrocatalyst layer.

The present invention provides a catalysed decal transfer substrate comprising a decal transfer substrate, an electrocatalyst later, and a layer D between the decal transfer substrate and the electrocatalyst layer which comprises an ion-conducting polymer and a carbon material. The layer D is configured such that, upon transfer of the electrocatalyst layer to a surface, at least a portion of the layer D remains attached to and is transferred with the electrocatalyst layer.

The present disclosure provides a fuel cell stack, a fuel cell system and a method for controlling a fuel cell stack, which can reduce obstruction of reactive gas fluid channels caused by freezing of retained water, while allowing size to be reduced. The fuel cell stack of the disclosure comprises water storage units that are formed between every two adjacent fuel cell unit cells, surrounded by the adjacent separators, the wall members and the gaskets, and that communicate with the reactive gas discharge manifold via the gaps of the wall members. The fuel cell system of the disclosure controls either or both the valve and compressor in a reactive gas supply channel and/or the valve in a reactive gas discharge channel, to cause liquid water retained in the water storage units to be discharged out of the fuel cell stack. The controlling method of the disclosure includes reducing the pressure in and scavenging the interior of the reactive gas discharge manifold, to cause the liquid water that has been discharged into the reactive gas discharge manifold to be discharged out of the fuel cell stack.

The present disclosure provides a fuel cell stack, a fuel cell system and a method for controlling a fuel cell stack, which can reduce obstruction of reactive gas fluid channels caused by freezing of retained water, while allowing size to be reduced. The fuel cell stack of the disclosure comprises water storage units that are formed between every two adjacent fuel cell unit cells, surrounded by the adjacent separators, the wall members and the gaskets, and that communicate with the reactive gas discharge manifold via the gaps of the wall members. The fuel cell system of the disclosure controls either or both the valve and compressor in a reactive gas supply channel and/or the valve in a reactive gas discharge channel, to cause liquid water retained in the water storage units to be discharged out of the fuel cell stack. The controlling method of the disclosure includes reducing the pressure in and scavenging the interior of the reactive gas discharge manifold, to cause the liquid water that has been discharged into the reactive gas discharge manifold to be discharged out of the fuel cell stack.

A metal support for an electrochemical element where the metal support includes a plate face, has a plate shape as a whole, and has a warping degree of 1.5×10.sup.−2 or less determined by calculating a least square value through the least squares method using at least three points in the plate face of the metal support, calculating a first difference between the least square value and a positive-side maximum displacement value on a positive side with respect to the least square value and a second difference between the least square value and a negative-side maximum displacement value on a negative side that is opposite to the positive side with respect to the least square value, and dividing the sum of the first difference and the second difference by a maximum length of the plate face of the metal support that passes through a center of gravity.

A metal support for an electrochemical element where the metal support includes a plate face, has a plate shape as a whole, and has a warping degree of 1.5×10.sup.−2 or less determined by calculating a least square value through the least squares method using at least three points in the plate face of the metal support, calculating a first difference between the least square value and a positive-side maximum displacement value on a positive side with respect to the least square value and a second difference between the least square value and a negative-side maximum displacement value on a negative side that is opposite to the positive side with respect to the least square value, and dividing the sum of the first difference and the second difference by a maximum length of the plate face of the metal support that passes through a center of gravity.

The invention relates to a bipolar plate assembly (1) for forming an electrolysis or fuel cell stack and to the use of a bipolar plate assembly and an electrolysis or fuel cell stack with a plurality of bipolar plate assemblies.

The invention relates to a bipolar plate assembly (1) for forming an electrolysis or fuel cell stack and to the use of a bipolar plate assembly and an electrolysis or fuel cell stack with a plurality of bipolar plate assemblies.

In an embodiment a fuel cell includes a cell stack having a plurality of unit cells stacked in a first direction, an end plate disposed on at least one of both side ends of the cell stack, an enclosure coupled to the end plate to surround a side portion of the cell stack, the enclosure being divided into a plurality of segments, a plate gasket disposed on the end plate and an enclosure gasket disposed between the plurality of segments, wherein one of the plate gasket and the enclosure gasket comprises a protruding portion protruding in the first direction, and a remaining one of the plate gasket and the enclosure gasket comprises a depressed portion depressed in the first direction to receive the protruding portion fitted thereinto.

A fuel cell, of proton-exchange-membrane type, includes, stacked in the following order: a first terminal, an end anode plate, a plurality of membrane plates having a bipolar plate between every two membrane plates, an end cathode plate and a second terminal Each bipolar plate includes, preassembled in the following order: a medial cathode plate and a medial anode plate, each medial anode, end anode, medial cathode and end cathode plate comprising at least one duct for distributing a reactant. The anode end plate is produced by a bipolar plate of the same orientation, and an anode capable of obturating all of the ducts of the medial cathode plate of this bipolar plate. The cathode end plate is produced by a bipolar plate of the same orientation, and a cathode capable of obturating all of the ducts of the medial anode plate of this bipolar plate.