Abstract: A system for fuel cell membrane edge protection includes a fuel cell including a fuel-cell membrane-subgasket assembly. The assembly includes an anode gas diffusion electrode and a cathode gas diffusion electrode configured for facilitating an electrochemical reaction. The reaction creates water as a by-product. The assembly further includes a proton exchange membrane disposed between the electrodes and a subgasket. The subgasket includes an interior aperture portion defined by a perimeter and is connected to the anode gas diffusion electrode and the membrane about the perimeter such that an area of overlap between the subgasket, the electrode, and the membrane exists around the perimeter. The assembly further includes a carbon paper layer spanning the interior aperture portion. The layer includes patterned wettability and is configured to move the water away from the area of overlap into a center portion of the layer.

Abstract: A method, fuel cell system and vehicle for maintaining compression via re-compression is provided. By recovering fuel cell stacks of the fuel cell system after a pre-determined time of operation and performing re-compression on each of the recovered fuel cell stacks, power generation capacity, active area pressure and seal force is recovered to address increased contact resistance and loss of fuel cell system power generation capacity as well as decreased seal force and increased risk of reactant gas and coolant leak.

Abstract: A battery cell monitoring system provides a direct measurement of electrical and heat distributions in a battery cell, using segmented elements that are in direct contact with an electrode of the battery. The battery cell monitoring system provides distributed local through-plane current, temperature, and pressure measurements with power for operation of the battery being supplied via battery tabs. An embodiment of a battery cell monitoring system includes a two-dimensional current collector array, a two-dimensional temperature sensor array, a plurality of pressure sensors, and a plurality of reference electrodes interspersed within the current collector array. The current collector array, the temperature sensor array, the pressure sensors, and the reference electrodes are arranged on a printed circuit board. The current collector array is configured to have direct physical contact with an electrode of the battery cell. The current collector array is disposed within a container of the battery cell.

Abstract: Presented are shock-force mitigation systems for fuel cell stacks, methods for making/using such systems, and electric-drive vehicles equipped with such systems. A fuel cell system includes multiple electrochemical fuel cells that are stacked face-to-face along a stack axis to define a fuel cell stack. A push plate abuts each longitudinal end of the fuel cell stack; these push plates translate rectilinearly along the stack axis inside a fuel cell stack housing. An end plate is located in facing spaced relation to each push plate to define a plate pair at each end of the stack. An active or passive force-modifying device is interposed between the two plates in each plate pair; these devices modify stack forces experienced by the fuel cell stack. For an active shock-force mitigation system, each force-modifying device may include a bladder system, spring, and/or linear actuator; an electronic system controller controls activation of the bladders/actuators.

Abstract: A fuel cell system includes a plurality of stacked bipolar plate assemblies. Each of the plurality of stacked bipolar plate assemblies includes a first subgasket including a first peripheral edge. The first subgasket supports a first membrane electrode assembly (MEA). A second subgasket including a second peripheral edge supports a second MEA. A bipolar plate is disposed between the first subgasket and the second subgasket. The bipolar plate has a first side defining a first plurality of passages receptive of a cathode fluid, a second side defining a second plurality of passages receptive of an anode fluid, and a plurality of coolant passages defined between the first subgasket and the second subgasket. A seal bead extends around the bipolar plate. The seal bead seals against the first subgasket and the second subgasket. A compliant energy attenuating bumper extends about the bipolar plate spaced from the seal bead.

Abstract: A fuel cell system includes a plurality of stacked bipolar plate assemblies. Each of the plurality of stacked bipolar plate assemblies includes a first subgasket including a first peripheral edge. The first subgasket supports a first membrane electrode assembly (MEA). A second subgasket including a second peripheral edge. The second subgasket supports a second MEA. A bipolar plate is disposed between the first subgasket and the second subgasket. The bipolar plate has a first side defining a first plurality of passages receptive of a cathode fluid, a second side defining a second plurality of passages receptive of an anode fluid, and a plurality of coolant passages defined between the first subgasket and the second subgasket. A seal bead extends around the bipolar plate. The seal bead seals against the first subgasket and the second subgasket. An energy attenuating bead extends about the bipolar plate spaced from the seal bead.

Abstract: An end plate unit for use in a fuel cell stack in an electric vehicle is provided wherein the end plate includes an outer surface, an inner surface disposed opposite the outer surface and a current collector. The inner surface defines at least a first region and a second region which is spaced apart from and substantially parallel to the first region. The current collector may be affixed to the inner surface.

Abstract: A method of manufacturing a fuel cell stack includes compressing a stack of bipolar plates with a variable applied load a feature non-deformed displacement distance, which is measured from an initial height of the stack of bipolar plates. A first applied load at a first displacement distance and a second applied load at a second displacement distance are sensed. The first displacement distance and the second displacement distance are each less than the feature non-deformed displacement distance. A best fit curve, passing through the first applied load at the first displacement distance and the second applied load at the second displacement distance, is then determined. A final displacement distance, measured from the initial height, is calculated from the best fit curve for a target applied load. The stack of bipolar plates is then compressed to the final displacement distance measured from the initial height.

Abstract: A fuel cell stack assembly for a vehicle is provided which includes a first end plate, a second end plate; and a first plurality of fuel cells disposed between the first and second end plates. The first plurality of fuel cells may define a repeating pattern of a thick fuel cell adjacent to a thin fuel cell. Each fuel cell in the first plurality of fuel cells having an active area thickness. The fuel cell stack assembly of the present disclosure may further include a second plurality of nominal fuel cells.

Abstract: A method for assembling a fuel cell stack for a vehicle is provided wherein the method includes the steps of: (1) providing a batch of fuel cells having varying active area thicknesses among each fuel cell; (2) measuring an active area thickness for each fuel cell in the batch of fuel cells and sorting each fuel cell in the batch of fuel cells into one of a first group, a second group, and a third group based on the active area thickness for each fuel cell; (3) assembling a target number of fuel cells to a target height from at least one of the first, second and third groups onto a first end plate; and (4) affixing a second end plate to the target number of fuel cells and the first end plate thereby creating a fuel cell stack.

Abstract: A composition with latent adhesion, fuel cell stack with a bipolar plate assembly with latent adhesion and a method of assembling a fuel cell stack with a seal that has latent adhesion such that reactant or coolant leakage through the seal is reduced. Bipolar plates within the stack include reactant channels and coolant channels that are fluidly coupled to inlet and outlet flowpaths, all of which are formed within a coolant-engaging or reactant-engaging surface of the plate. One or more thin or low aspect-ratio seals are formed on a metal bead that is integrally formed on a surface of the plate and is used to help reduce leakage by maintaining fluid isolation of the reactants and coolant as they flow through their respective channels and flowpaths that are defined between adjacently placed plates.

Abstract: A fuel cell stack with a bipolar plate assembly and a method of assembling a fuel cell stack such that reactant or coolant leakage is reduced. Bipolar plates within the system include reactant channels and coolant channels that are fluidly coupled to inlet and outlet flowpaths, all of which are formed within a coolant-engaging or reactant-engaging surface of the plate. One or more thin or low aspect-ratio microseals are also formed on a metal bead that is integrally-formed on a surface of the plate and is used to help reduce leakage by maintaining fluid isolation of the reactants and coolant as they flow through their respective channels and flowpaths that are defined between adjacently-placed plates.

Abstract: A fuel cell stack includes a plurality of cell groups and a controller wherein each cell group comprises a plurality of fuel cells and a group sensor which measures one or more electrical characteristics of the respective cell group. The controller comprises one or more processors and memory and is communicatively coupled to each group sensor. The one or more processors execute machine readable instructions to compare a measured electrical characteristic of each cell group to one or more thresholds stored in memory, and indicate the need for diagnostics of the fuel cell stack when the comparison indicates a non-systemic event.

Abstract: A membrane-electrode assembly (MEA) for use in electrical applications, for example in polymer electrolyte fuel cells (PEFCs), includes a protective high-stiffness interlayer coating interposed between a gas diffusion layer and an ion conducting membrane layer, and includes also a catalyst layer. The interlayer mitigates electrical shorting across the ion conducting membrane layer, for example by providing mechanical support against fiber protrusions from the gas diffusion layers into the ion conducting membrane layer or by smoothing the roughness of the gas diffusion layer. The interlayer is typically a mixture of carbon black and one or more ionomers, and its properties are controlled by modulating its thickness, mechanical modulus, ionomer loading, and electrical conductivity.

Abstract: A method for assembling a fuel cell stack for a vehicle is provided wherein the method includes the steps of: (1) providing a batch of fuel cells having varying active area thicknesses among each fuel cell; (2) measuring an active area thickness for each fuel cell in the batch of fuel cells and sorting each fuel cell in the batch of fuel cells into one of a first group, a second group, and a third group based on the active area thickness for each fuel cell; (3) assembling a target number of fuel cells to a target height from at least one of the first, second and third groups onto a first end plate; and (4) affixing a second end plate to the target number of fuel cells and the first end plate thereby creating a fuel cell stack.

Abstract: A fuel cell stack assembly for a vehicle is provided which includes a first end plate, a second end plate; and a first plurality of fuel cells disposed between the first and second end plates. The first plurality of fuel cells may define a repeating pattern of a thick fuel cell adjacent to a thin fuel cell. Each fuel cell in the first plurality of fuel cells having an active area thickness. The fuel cell stack assembly of the present disclosure may further include a second plurality of nominal fuel cells.

Abstract: A method of manufacturing a fuel cell stack includes compressing a stack of bipolar plates with a variable applied load a feature non-deformed displacement distance, which is measured from an initial height of the stack of bipolar plates. A first applied load at a first displacement distance and a second applied load at a second displacement distance are sensed. The first displacement distance and the second displacement distance are each less than the feature non-deformed displacement distance. A best fit curve, passing through the first applied load at the first displacement distance and the second applied load at the second displacement distance, is then determined. A final displacement distance, measured from the initial height, is calculated from the best fit curve for a target applied load. The stack of bipolar plates is then compressed to the final displacement distance measured from the initial height.

Abstract: An end plate unit for use in a fuel cell stack in an electric vehicle is provided wherein the end plate includes an outer surface, an inner surface disposed opposite the outer surface and a current collector. The inner surface defines at least a first region and a second region which is spaced apart from and substantially parallel to the first region. The current collector may be affixed to the inner surface.

Abstract: A number of variations may include a product that may include a fuel cell stack assembly that may include at least one bipolar plate that may include at least one raised bead and at least one raised limiter.

Abstract: A fuel cell stack that includes a gas diffusion media for the end cells in the stack that has less of an intrusion into the flow field channels of the end cells that the other cells, so as to increase the flow rate through the flow channels in the end cells relative to the flow rate through the flow channels in the other cells. A different diffusion media can be used in the end cells than the nominal cells, where the end cell diffusion media has less of a channel intrusion as a result of diffusion media characteristics. Also, the same diffusion media could be used in the end cells as the nominal cells, but the end cell diffusion media layers could be thinner than the nominal cell diffusion media layers. Further, a higher amount of pre-compression can be used for the diffusion media in the end cells.