Abstract: A fuel cell includes a plurality of unit cells disposed in a stack. Each unit cell includes a membrane electrode assembly (MEA) having an anode and a cathode and a bipolar plate having a cathode side defining a recessed pocket in fluid communication with an air port, an anode side, and coolant channels between the cathode and anode sides. The bipolar plate is disposed against the MEA such that the cathode is disposed over the pocket. A flow guide is disposed in the pocket with a front side facing the MEA and a back side facing a bottom of the pocket. The flow guide has a plurality of embossments.

Abstract: A bipolar plate for a fuel cell includes an anode plate and a cathode plate. The anode plate has hydrogen flow channels on a first side of the anode plate and coolant channels on a second side of the anode plate. The cathode plate has a first side disposed against the second side of the anode plate to cover the coolant channels and has a second side defining a recessed pocket configured to receive a stream of air. A flow guide is disposed in the pocket such that an inlet manifold is formed along a first edge of the flow guide and an outlet manifold is formed along a second edge of the flow guide. The flow guide defines channels extending from the inlet manifold to the outlet manifold. A plurality of openings is defined by through the flow guide.

Abstract: Systems and methods for forming a workpiece are disclosed. The system may include a fixture assembly for receiving a workpiece having opposing first and second surfaces, first and second tools, and a vibration source configured to vibrate the first and/or second tool. The first and second tools may be configured to move along first and second predetermined paths of motion as the first and/or second tool is vibrated by the vibration source and may exert force on the first and second surfaces to form the workpiece. The method may include vibrating a tool using a vibration source and moving the vibrating tool and another tool along first and second forming paths to form the workpiece. The vibration source may be an ultrasonic transducer and may vibrate the tool at a frequency of at least 1 kHz.

Abstract: A bipolar plate for a fuel cell includes an anode plate and a cathode plate. The anode plate has hydrogen flow channels on a first side of the anode plate and coolant channels on a second side of the anode plate. The cathode plate has a first side disposed against the second side of the anode plate to cover the coolant channels and has a second side defining a recessed pocket configured to receive a stream of air. A flow guide is disposed in the pocket such that an inlet manifold is formed along a first edge of the flow guide and an outlet manifold is formed along a second edge of the flow guide. The flow guide defines channels extending from the inlet manifold to the outlet manifold. A plurality of openings is defined by through the flow guide.

Abstract: A fuel cell assembly including a plate assembly having an anode inlet, a cathode inlet, a first coolant inlet, and a second coolant inlet is provided. The first coolant inlet is located adjacent the anode inlet on a first plate side. The second coolant inlet is located adjacent the cathode inlet on a second plate side. The inlets are arranged such that coolant influences reactant temperature at the anode and cathode inlets to encourage formation of a membrane uniform hydration distribution during fuel cell operation. The fuel cell assembly may include a hydrogen channel, an oxygen channel, and a coolant channel. The coolant channel may extend between the hydrogen channel and the oxygen channel to draw heat from hydrogen and oxygen flowing therethrough and such that the hydrogen and oxygen are close enough to one another for chemical reaction therebetween.

Abstract: Systems and methods for forming a workpiece are disclosed. The system may include a fixture assembly for receiving a workpiece having opposing first and second surfaces, first and second tools, and a vibration source configured to vibrate the first and/or second tool. The first and second tools may be configured to move along first and second predetermined paths of motion as the first and/or second tool is vibrated by the vibration source and may exert force on the first and second surfaces to form the workpiece. The method may include vibrating a tool using a vibration source and moving the vibrating tool and another tool along first and second forming paths to form the workpiece. The vibration source may be an ultrasonic transducer and may vibrate the tool at a frequency of at least 1 kHz.

Abstract: Systems and methods for forming a workpiece are disclosed. The system may include a fixture assembly for receiving a workpiece having opposing first and second surfaces, first and second tools, and a vibration source configured to vibrate the first and/or second tool. The first and second tools may be configured to move along first and second predetermined paths of motion as the first and/or second tool is vibrated by the vibration source and may exert force on the first and second surfaces to form the workpiece. The method may include vibrating a tool using a vibration source and moving the vibrating tool and another tool along first and second forming paths to form the workpiece. The vibration source may be an ultrasonic transducer and may vibrate the tool at a frequency of at least 1 kHz.

Abstract: A fuel cell assembly including a plate assembly having an anode inlet, a cathode inlet, a first coolant inlet, and a second coolant inlet is provided. The first coolant inlet is located adjacent the anode inlet on a first plate side. The second coolant inlet is located adjacent the cathode inlet on a second plate side. The inlets are arranged such that coolant influences reactant temperature at the anode and cathode inlets to encourage formation of a membrane uniform hydration distribution during fuel cell operation. The fuel cell assembly may include a hydrogen channel, an oxygen channel, and a coolant channel. The coolant channel may extend between the hydrogen channel and the oxygen channel to draw heat from hydrogen and oxygen flowing therethrough and such that the hydrogen and oxygen are close enough to one another for chemical reaction therebetween.

Abstract: A fuel cell assembly includes a pair of corrugated bipolar plates. Each of the plates is defined by peak portions and sidewalls connecting the peak portions. The plates are fitted and nested within each other such that the sidewalls are in direct contact. Some of the sidewalls include a stepped shoulder portion such that each of the some of the sidewalls and the peak portions adjacent thereto form a stair-step profile and define a flow channel having a depth greater than a width.

Abstract: A fuel-cell stack including treated bipolar plates is disclosed, as well as methods of treatment. The bipolar plates may include an active region wherein a fuel-cell reaction is configured to occur and an inactive region configured to supply, collect, and remove fluids from the active region. The inactive region may include one or more exit vias defined by the bipolar plate and having an inner surface configured to contact fluids received from the active region. At least a portion of the inner surface may have a hydrophobic textured surface. The methods may include treating a metal inner surface of an exit via defined in an inactive region of a fuel-cell bipolar plate that is configured to contact fluids received from an active region of the fuel-cell bipolar plate. The treatment may include removing material to form a hydrophobic textured surface on at least a portion of the inner surface.

Abstract: A method of operating a fuel cell stack including, prior to shut down, flowing dry purge gas from an inlet port to an outlet port of a fuel cell stack unit cell to purge water from the fuel cell stack and subsequently flowing dry purge gas from the outlet port to the inlet port to further purge water from the fuel cell stack.

Abstract: A fuel cell stack includes a membrane electrode assembly and a bipolar plate. The bipolar plate has a corrugated portion defined by an adjacent pair of proximal and distal peak portions and a sidewall segment connecting the peak portions. The sidewall segment and membrane electrode assembly at least partially define a flow channel. The sidewall segment includes a shoulder portion defining a step spaced away from the peak portions.

Abstract: A fuel cell assembly includes a pair of corrugated bipolar plates. Each of the plates is defined by peak portions and sidewalls connecting the peak portions. The plates are fitted and nested within each other such that the sidewalls are in direct contact. Some of the sidewalls include a stepped shoulder portion such that each of the some of the sidewalls and the peak portions adjacent thereto form a stair-step profile and define a flow channel having a depth greater than a width.

Abstract: Systems and methods for forming a workpiece are disclosed. The system may include a fixture assembly for receiving a workpiece having opposing first and second surfaces, first and second tools, and a vibration source configured to vibrate the first and/or second tool. The first and second tools may be configured to move along first and second predetermined paths of motion as the first and/or second tool is vibrated by the vibration source and may exert force on the first and second surfaces to form the workpiece. The method may include vibrating a tool using a vibration source and moving the vibrating tool and another tool along first and second forming paths to form the workpiece. The vibration source may be an ultrasonic transducer and may vibrate the tool at a frequency of at least 1 kHz.

Abstract: A method is provided for welding workpieces together while minimizing distortion in those workpieces. That method includes loading the workpieces to be welded together into a periphery clamp welding fixture. This is followed by tack welding the workpieces together by means of spot welds. Next is the removing of a portion of the welding fixture in order to provide an open field with respect to the workpieces and then completing welding of the workpieces together in the open field. Thus, the entire weld process may be completed utilizing a single periphery clamp welding fixture.

Abstract: A fuel cell stack includes a membrane electrode assembly and a bipolar plate. The bipolar plate has a corrugated portion defined by an adjacent pair of proximal and distal peak portions and a sidewall segment connecting the peak portions. The sidewall segment and membrane electrode assembly at least partially define a flow channel. The sidewall segment includes a shoulder portion defining a step spaced away from the peak portions.

Abstract: A fuel cell stack includes a membrane electrode assembly and a bipolar plate. The bipolar plate has a corrugated portion defined by an adjacent pair of proximal and distal peak portions and a sidewall segment connecting the peak portions. The sidewall segment and membrane electrode assembly at least partially define a flow channel. The sidewall segment includes a shoulder portion defining a step spaced away from the peak portions.

Abstract: An ultrasonic welding apparatus having an extractable sonotrode. The sonotrode having a non-threaded outer peripheral surface and a tapered mating surface that meets with a correspondingly tapered aperture formed in the end of the reed of the ultrasonic welding apparatus. In the preferred embodiment the ultrasonic welding apparatus includes a sonotrode removal mechanism for extracting the sonotrode from the reed.

Abstract: A motor vehicle structural energy absorbing member (12) is light weight and is made in a manner to produce random or directionally oriented, elongated pores or voids (16) in a structural matrix (14) in a manner that permits tailoring of impact energy absorption in one or more direction(s) to provide an integral energy absorbing region.