Molten carbonate fuel cell configurations are provided that allow for introduction of an anode input gas flow on a side of the fuel cell that is adjacent to the entry side for the cathode input gas flow while allowing the anode and cathode to operate under co-current flow and/or counter-current flow conditions. It has been discovered that improved flow properties can be achieved within the anode or cathode during co-current flow or counter-current flow operation by diverting the input flow for the anode or cathode into an extended edge seal region (in an extended edge seal chamber) adjacent to the active area of the anode or cathode, and then using a baffle to provide sufficient pressure drop for even flow distribution of the anode input flow across the anode or cathode input flow across the cathode. A second baffle can be used to create a pressure drop as the anode output flow or cathode output flow exits from the active area into a second extended edge seal region (in a second extended edge seal chamber) prior to leaving the fuel cell.

A plurality of channel elements provided in a bipolar plate have different widths depending on positions, so that the velocity of flow of the fluid increases from an inlet toward an outlet of the bipolar plate and water generated when the fluid is condensed on the downstream side of the bipolar plate can be discharged more smoothly. In addition, a plurality of channel elements have different contact angles depending on positions of the plurality of channel elements so that the contact angle increases toward the outlet side of the bipolar plate. Thus, the reaction gas can be more concentrated on the surface of a gas diffusion layer. Even if the concentration of the reaction gas is reduced at the outlet side of the bipolar plate, the diffusion of the reaction gas is well performed, so that performance reduction can be prevented.

A plurality of channel elements provided in a bipolar plate have different widths depending on positions, so that the velocity of flow of the fluid increases from an inlet toward an outlet of the bipolar plate and water generated when the fluid is condensed on the downstream side of the bipolar plate can be discharged more smoothly. In addition, a plurality of channel elements have different contact angles depending on positions of the plurality of channel elements so that the contact angle increases toward the outlet side of the bipolar plate. Thus, the reaction gas can be more concentrated on the surface of a gas diffusion layer. Even if the concentration of the reaction gas is reduced at the outlet side of the bipolar plate, the diffusion of the reaction gas is well performed, so that performance reduction can be prevented.

A coolant flow field of a fuel cell stack includes a power-generation-portion-cooling flow path including a portion overlapping a power generation section of a membrane electrode assembly, a bypass flow path provided on outer peripheries of separators, a main supply flow path extending from a coolant supply passage through the bypass flow path and communicating with the power-generation-portion-cooling flow path, and a bubble release flow path extending from an upper portion of the coolant supply passage in the gravity direction toward the bypass flow path and communicating with the bypass flow path, wherein the bubble release flow path extends upward in the gravity direction above the coolant supply passage.

A coolant flow field of a fuel cell stack includes a power-generation-portion-cooling flow path including a portion overlapping a power generation section of a membrane electrode assembly, a bypass flow path provided on outer peripheries of separators, a main supply flow path extending from a coolant supply passage through the bypass flow path and communicating with the power-generation-portion-cooling flow path, and a bubble release flow path extending from an upper portion of the coolant supply passage in the gravity direction toward the bypass flow path and communicating with the bypass flow path, wherein the bubble release flow path extends upward in the gravity direction above the coolant supply passage.

An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

A fuel cell includes: an electrolyte membrane; first and second catalyst layers respectively formed on first and second surfaces of the electrolyte membrane; and a separator, the first catalyst layer being arranged between the separator and the electrolyte membrane, wherein the separator includes first and second grooves through which reactant gas flows between the first catalyst layer and the separator.

An illustrative example fuel cell component includes a plate with a plurality of flow channels in at least one side of the plate. Each of the flow channels has a length between an inlet and an outlet. Each of the flow channels has a width and a depth, which are transverse to the length. At least some of the flow channels include a portion near the inlet and the width or the depth of the portion is greater than the width or depth along a majority of the length of those flow channels.

An illustrative example fuel cell component includes a plate with a plurality of flow channels in at least one side of the plate. Each of the flow channels has a length between an inlet and an outlet. Each of the flow channels has a width and a depth, which are transverse to the length. At least some of the flow channels include a portion near the inlet and the width or the depth of the portion is greater than the width or depth along a majority of the length of those flow channels.