Gm Global Technolgoy Operations, Inc.

Honda Motor Co., Ltd.

David A Martinchek

Robert C Thompson

Ian R Jermy

Jeffrey M Guzda

Hiroyuki Tanaka

Masaaki Sakano

David A Southwick

Martin Heinzmann

Thomas D Bronchetti

A fuel cell stack and a method of assembling a fuel cell stack includes compressing fuel cells along their stacking axis. A compression retention device made up of an enclosure may be used with one or more optional insertable shims to correct for any stack height variations. Significantly, the enclosure is formed to allow the stack to be loaded in compression by a press such that the cells that make up the stack are placed into and maintained in a substantially compressed state while the compression force is not imparted to the enclosure. By resolving any stack height variances while the cells of the stack are maintained in their substantially compressed state, assembly operations are simplified in that repeated compression and decompression of the stack is avoided while trying to ensure that the stack and enclosure are joined into their final assembly form.

Fuel cell stack and assembly method of same

A passive tortuous path drain for a directing fluid flow from an enclosure includes a drain body having a front face and a back face. The front face defines a curved trenched channel having a first curved channel end and a second curved channel end. The front face also defines a second trenched channel. The drain body defines at least one egress opening in fluid communication with the second trenched channel. The first curved channel end and a second curved channel end are in fluid communication with the second trenched channel. Characteristically, the drain is adapted to be positioned adjacent to a drain opening in an enclosure such that liquid flows from the drain opening to the curved trenched channel and then to the second trenched channel exiting through the egress opening.

Passive tortuous path drain

Methods, apparatus, and systems for improving and/or simplifying one or more seals in a fuel cell stack, such as a vehicle fuel cell stack. In some implementations, a plate or assembly for the stack may be extruded through an extrusion die so as to create a plate comprising a top surface, a bottom surface, and a plurality of cavities disposed between the top and bottom surfaces. At least a subset of the cavities may be filled with a cavity-filler material distinct from a material used to form the plate, such as a foam material. One or more headers, such as grommet seals, may then be overmolded into the plate to form corresponding conduits between the top surface and the bottom surface of the plate/assembly.

Fuel cell stack sealing methods, apparatus, and systems

A system and method for assembling and compressing a fuel cell stack. The system and method include a fuel cell stack housing with a plurality of side walls that create an enclosure that is open on two opposing ends, at least one channel formed on an inner side wall surface, and a first end structural frame that is affixed to one of the open ends of the housing, the first end structural frame including at least one tooling opening through a planar surface. The system and method further include tooling that passes through the at least one tooling opening of the first end structural frame and that extends up through the housing to the open end of the housing, the tooling capable of moving down incrementally while fuel cell stack components are being loaded into the housing through the open end that is opposite to the first end structural frame.

Fuel cell stack assembly-compression system

A membrane humidifier assembly for a membrane humidifier for a fuel cell system and a method for making the same is disclosed, the method comprising the steps of providing a material for forming a diffusion medium; forming a plurality of channels in the material with one of a channel-forming roller, a means for etching the material, and a press for forming the diffusion medium; and providing a pair of membranes, wherein the diffusion medium is disposed between the pair of membranes.

Method for forming channels on diffusion media for a membrane humidifier

Systems and methods are disclosing providing for a fuel cell ('FC') stack assembly utilizing bus bars that accommodate for variations in FC stack heights during assembly. In some embodiments, bus bars consistent with embodiments disclosed herein may be integrally formed with terminal plates out of a single piece of conductive material. Further embodiments of the bus bars disclosed herein may include structures configured to facilitating cooling of the bus bars during operation of the FC system.

Fuel cell stack bus bar assembly systems and methods

A water vapor transfer unit having fluid flow conduits which distribute wet or dry fluid throughout the water vapor transfer unit, which are created by forming apertures in each wet and dry plate so that when the plates are stacked, fluid flow inlet and outlet headers are integrated into the flow stack. These integrated headers negate the need for traditional wet and dry fluid inlet and outlet manifolds external to the water vapor transfer unit stack. Because the plates are stacked and sealed so that the fluid flows cannot co-mingle, the fluids are introduced directly into the stack, flow across the flow fields, and exit the stack without leakage or flow contamination. The integrated header design allows for sealing the stack on no more than a single plane defined by the stack or on no more than two parallel opposing planes and allows for accommodation of stack expansion and contraction.

Plate-style water vapor transfer unit with integral headers

A system and method for aligning and reducing the relative movement between adjacent fuel cells within a fuel cell stack. The inter-cell cooperation between fuel cells along a stacking dimension is enhanced by one or more datum placed along the edge of a bipolar plate that makes up a part of a cell-containing assembly. The datum is shaped along a thickness that substantially coincides with the cell stacking dimension to avoid shifting between adjacently-stacked cells that may otherwise arise out of the occurrence of a significant acceleration along the dimension that defines the major surfaces of the plates, cells and their respective assemblies. By having the datum be integrally formed with numerous stacked cells, the need to affix individual tabs each plate is avoided.

Fuel cell stack assembly&#x2014;datum design for fuel cell stacking and collision protection

A system and method for aligning and reducing the relative movement between adjacent fuel cells within a fuel cell stack. The inter-cell cooperation between fuel cells along a stacking dimension is enhanced by one or more datum placed along the edge of a bipolar plate that makes up a part of a cell-containing assembly. The datum is shaped along a thickness dimension that substantially coincides with the cell stacking dimension to promote a nested fit with a comparable datum on an adjacently-stacked bipolar plate. This nesting facilitates an interference fit that enhances the resistance to sliding movement between respective cells that may otherwise arise out of the occurrence of a significant acceleration along the dimension that defines the major surfaces of the plates, cells and their respective assemblies. In one form, the use of welding, bonding or related attachment of the datum to the plate promotes enhanced metallic support without the need for increasing the plate footprint and without having to overmold the datum directly onto the plate.

A fuel cell system having compression retention features that functions dually to provide compression retention and to provide structural sealing and vehicle mounting capability, eliminating the bulk of an additional structural enclosure while retaining the balance of plant simplicity associated with the use of structural enclosures. The fuel cell system has fuel cells disposed between a dry end unit plate and a wet end unit plate and a compression retention system with a pair of opposing end caps and a pair of opposing side panels such that wet end unit plate is fixedly secured to the opposing end caps and the dry end unit plate is adjustably secured to the opposing end caps. Methods for eliminating the effect of stack height variance and balance of plant tolerances on fuel cell system installation are also provided.

Fuel cell stack compression system having integrated vehicle mounts

A water vapor transfer separator plate assembly and a method of making the same. In such an assembly made up of a stack of alternating wet side plates and dry side plates with a membrane disposed between them, a humid fluid such as that found in a fuel cell cathode exhaust flows against one side of each membrane such that at least some of its moisture content travels across the membrane to a lower humidity fluid on the opposite side of the membrane. The lower humidity fluid, such as that found in a fuel cell cathode entrance, experiences an increase in its humidity by the operation of the moisture flow across the membrane. At least a portion of the assembly may be made thinner by removing diffusion media and reinforcing structure of the dry side plates such that the overall assembly is simplified.

Discretely supported wet side plates

A bypass unit for a water vapor transfer assembly includes a main body, a check valve, and an adjustable flow regulator. The main body has a conduit formed therethrough. The check valve is in communication with the conduit. The check valve normally militates against a flow of a bypass stream through the conduit and permits the flow of the bypass stream through the conduit above a threshold flow rate. The flow regulator is in communication with the conduit. The flow regulator permits an adjustment of the flow of the bypass stream to modify the water transfer rate of the water transfer assembly.

Adjustable air flow bypass in a water vapor transfer assembly to reduce beginning of life water transfer variation

A water vapor transfer assembly for a fuel cell system includes at least one water vapor transfer device. The water vapor transfer device permits a transfer of water from a wet stream to a dry stream. The water vapor transfer device is disposed between a pair of end plates. The end plates each have a plurality of outwardly extending ribs. The water vapor transfer device and the end plates are disposed within a housing having a pair of wet stream apertures and a pair of dry stream apertures formed therein. The housing further includes a plurality of channels formed adjacent the dry stream apertures. The channels are in fluid communication with the wet stream apertures. The outwardly extending ribs of the end plates cooperate with the channels to define a tortuous bypass flow path between the wet stream apertures of the housing.

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Spencerport, NY, United States of America

David A Martinchek