This fuel cell is provided with a first electrolyte membrane electrode structure and a second electrolyte membrane electrode structure, respective cathode electrodes of which face each other with an oxidant gas supply layer being interposed therebetween. The oxidant gas supply layer has: a first projection part which presses an interconnect part of an electrolyte membrane that constitutes the first electrolyte membrane electrode structure; and a second projection part which presses an interconnect part of an electrolyte membrane that constitutes the second electrolyte membrane electrode structure.

This fuel cell is provided with a first electrolyte membrane electrode structure and a second electrolyte membrane electrode structure, respective cathode electrodes of which face each other with an oxidant gas supply layer being interposed therebetween. The oxidant gas supply layer has: a first projection part which presses an interconnect part of an electrolyte membrane that constitutes the first electrolyte membrane electrode structure; and a second projection part which presses an interconnect part of an electrolyte membrane that constitutes the second electrolyte membrane electrode structure.

A plurality of anode wavy portions provided in an anode separator of a fuel cell have wavy patterns in the same phase, and are arranged in an amplitude direction of the anode wavy portions at a first pitch. A plurality of cathode wavy portions provided in a cathode separator have wavy patterns in the same phase but in reverse phase with respect to the anode wavy portions, and are arranged in an amplitude direction of the cathode wavy portions at a second pitch. The first pitch and the second pitch have different sizes.

A plurality of anode wavy portions provided in an anode separator of a fuel cell have wavy patterns in the same phase, and are arranged in an amplitude direction of the anode wavy portions at a first pitch. A plurality of cathode wavy portions provided in a cathode separator have wavy patterns in the same phase but in reverse phase with respect to the anode wavy portions, and are arranged in an amplitude direction of the cathode wavy portions at a second pitch. The first pitch and the second pitch have different sizes.

A fuel cell having an ion-selective separator, a gas diffusion layer and a separator plate, is provided. The separator plate forms, together with the gas diffusion layer, at least one gas-conducting flow field. At least one convergent duct section and at least one divergent duct section are formed in the flow field, wherein the convergent duct section lies adjacent to the divergent duct section. A barrier is provided between the convergent duct section and the divergent duct section such that the gas flows at least partially through the gas diffusion layer in order to pass directly from the convergent duct section into the divergent duct section. At least one additional convergent duct section, at least one additional divergent duct section and at least one additional barrier are provided downstream of the convergent duct section and/or downstream of the divergent duct section.

A fuel cell having an ion-selective separator, a gas diffusion layer and a separator plate, is provided. The separator plate forms, together with the gas diffusion layer, at least one gas-conducting flow field. At least one convergent duct section and at least one divergent duct section are formed in the flow field, wherein the convergent duct section lies adjacent to the divergent duct section. A barrier is provided between the convergent duct section and the divergent duct section such that the gas flows at least partially through the gas diffusion layer in order to pass directly from the convergent duct section into the divergent duct section. At least one additional convergent duct section, at least one additional divergent duct section and at least one additional barrier are provided downstream of the convergent duct section and/or downstream of the divergent duct section.

An electrolyzer or unitized regenerative fuel cell has a flow field with at least one channel, wherein the cross-sectional area of the channel varies along at least a portion of the channel length. In some embodiments the channel width decreases along at least a portion of the length of the channel according to a natural exponential function. The use of this type of improved flow field channel can improve performance and efficiency of operation of the electrolyzer device.

An electrolyzer or unitized regenerative fuel cell has a flow field with at least one channel, wherein the cross-sectional area of the channel varies along at least a portion of the channel length. In some embodiments the channel width decreases along at least a portion of the length of the channel according to a natural exponential function. The use of this type of improved flow field channel can improve performance and efficiency of operation of the electrolyzer device.

A separator for a fuel cell having a flow channel including a transverse channel and a longitudinal channel formed therein, the transverse channel having a pair of opposed side walls, and a first pattern and a second pattern alternately spaced and arranged in the transverse channel is provided. Each of the first pattern and the second pattern is a column-shaped three-dimensional structure having a polygonal transverse section. The first pattern and the second pattern are arranged in the transverse channel so as to have a shape of the transverse sections being rotated 180° relative to each other. First spacing distances from each of the first pattern and the second pattern to a first side wall of the pair of opposed side walls of the transverse channel are different.

A separator for a fuel cell having a flow channel including a transverse channel and a longitudinal channel formed therein, the transverse channel having a pair of opposed side walls, and a first pattern and a second pattern alternately spaced and arranged in the transverse channel is provided. Each of the first pattern and the second pattern is a column-shaped three-dimensional structure having a polygonal transverse section. The first pattern and the second pattern are arranged in the transverse channel so as to have a shape of the transverse sections being rotated 180° relative to each other. First spacing distances from each of the first pattern and the second pattern to a first side wall of the pair of opposed side walls of the transverse channel are different.