Protected membrane electrode assembly for fuel cell

Abstract

A membrane electrode assembly (MEA) for a fuel cell. The MEA may include a first gas diffusion electrode (GDE) layer, a second GDE layer, a subgasket, and a membrane sandwiched between the first and second GDE layers. The MEA may also include a protective barrier configured to protect the membrane from external contaminants. The protective barrier may be configured to surround a perimeter of the film between the surrounding sub-gasket portion and the second GDE layer.

Description

Technical Field

[0001] The present disclosure relates to protecting a membrane electrode assembly (MEA) from external contaminants, such as, but not necessarily limited to, protecting a MEA used in a gas diffusion electrode (GDE) fuel cell architecture. Background Art

[0002] In a GDE architecture, an unprotected membrane may include edges, perimeters, or other surfaces that are exposed to external contaminants. This exposure may occur between GDE layers to the extent that a path may be created for lifetime-limiting contaminants, such as cations, to reach and react with the membrane. One reaction of concern may result from Fe2+ ions entering or interacting with the membrane, resisting and potentially destroying the membrane's chemical structure over time. Summary of the invention

[0003] One non-limiting aspect of the present disclosure relates to protecting a membrane from contamination, such as using a protected membrane electrode assembly (MEA) having a protective barrier configured to protect the membrane from external contaminants. The protected MEA can be configured for use with a variety of gas diffusion electrode (GDE) architectures, including but not limited to those used in fuel cells to provide electrical power to a motor used to propel a vehicle.

[0004] One non-limiting aspect of the present disclosure relates to a protected membrane electrode assembly (MEA) for a fuel cell. The protected MEA may include an anode gas diffusion electrode (GDE) layer having an anode top surface and an anode bottom surface, a cathode GDE layer having a cathode top surface and a cathode bottom surface, a membrane having a membrane top surface and a membrane bottom surface and the membrane bottom surface is attached to the cathode top surface, a subgasket having a subgasket top surface and a subgasket bottom surface and the subgasket bottom surface is attached to the membrane top surface and the subgasket top surface is attached to the anode bottom surface, and a protective barrier configured to protect the membrane from external contaminants. The protective barrier may surround the periphery of the membrane between the subgasket bottom surface and the cathode top surface.

[0005] The protected MEA may include a side perimeter portion of the cathode GDE layer forming at least a portion of the protective barrier.

[0006] The protected MEA may include a side perimeter portion that is bent upward relative to an inner portion of the cathode GDE layer such that the side perimeter portion is pressed against the subgasket bottom surface.

[0007] The protected MEA may include side perimeter portions that may be formed by removing sections of the membrane after the membrane has been attached to the cathode GDE layer.

[0008] The protected MEA may include sections removed from the membrane as part of the laser ablation process.

[0009] The protected MEA may include sections that are removed from the membrane as part of the die cutting process.

[0010] The protected MEA may include a side peripheral portion of the membrane forming at least a portion of the protective barrier.

[0011] The protected MEA may include side peripheral portions corresponding to an outer band of the membrane that is offset by a channel from an inner portion of the membrane.

[0012] A protected MEA may include channels that are free of the material comprising the membrane.

[0013] A protected MEA may include channels formed by removing sections of the membrane after the membrane has been attached to the cathode GDE layer.

[0014] The protected MEA may include sections removed from the membrane as part of a laser ablation process or a die cutting process.

[0015] One non-limiting aspect of the present disclosure relates to a method of manufacturing a protected membrane electrode assembly (MEA) for a fuel cell. The method may include receiving an anode gas diffusion electrode (GDE) layer having an anode top surface and an anode bottom surface, receiving a cathode GDE layer having a cathode top surface and a cathode bottom surface, receiving a membrane having a membrane top surface and a membrane bottom surface, receiving a subgasket having a subgasket top surface and a subgasket bottom surface, removing a membrane portion of the membrane to provide a protective barrier for protecting the membrane from external contaminants, adhering the anode bottom surface to the subgasket top surface and the membrane top surface, and adhering the subgasket bottom surface to the membrane top surface so that the protective barrier surrounds the perimeter of the membrane between the subgasket bottom surface and the cathode top surface.

[0016] The method may include providing the protective barrier based at least in part on bending a cathode portion of the cathode GDE layer that coincides with the membrane portion upward relative to an interior portion of the cathode GDE layer such that at least a portion of the cathode portion is pressed against the subgasket bottom surface.

[0017] The method may include providing the protective barrier based at least in part on removing the membrane portion such that the membrane is separated into an outer membrane band and an inner membrane portion, the outer membrane band surrounding the inner membrane portion and offset from the inner membrane portion by a channel.

[0018] The method may include removing the membrane portion after the membrane bottom surface has been adhered to the cathode top surface.

[0019] The method may include removing portions of the membrane before the bottom surface of the membrane is adhered to the cathode top surface.

[0020] One non-limiting aspect of the present disclosure relates to a protected membrane electrode assembly (MEA) for a fuel cell. The protected MEA may include a first gas diffusion electrode (GDE) layer, a second GDE layer, a subgasket, a membrane sandwiched between the first and second GDE layers and at least a peripheral subgasket portion of the subgasket, and a protective barrier configured to protect the membrane from external contaminants. The protective barrier may surround the periphery of the membrane between the peripheral subgasket portion and the second GDE layer.

[0021] The protected MEA may include the protection barrier formed with a bent portion of the second GDE layer.

[0022] The protected MEA may include a protection barrier formed with channels shaped to separate the membrane into an outer membrane strip and an inner membrane portion.

[0023] The protected MEA may include a protection barrier formed by removing a portion of the membrane.

[0024] The present invention also includes the following scheme:

[0025] Solution 1. A protected membrane electrode assembly (MEA) for a fuel cell, comprising:

[0026] an anode gas diffusion electrode (GDE) layer having an anode top surface and an anode bottom surface;

[0027] a cathode GDE layer having a cathode top surface and a cathode bottom surface;

[0028] a membrane having a membrane top surface and a membrane bottom surface, wherein the membrane bottom surface is attached to the cathode top surface;

[0029] a subgasket having a subgasket top surface and a subgasket bottom surface, wherein the subgasket bottom surface is attached to the membrane top surface and the subgasket top surface is attached to the anode bottom surface; and

[0030] A protective barrier configured to protect the membrane from external contaminants surrounds a perimeter of the membrane between the subgasket bottom surface and the cathode top surface.

[0031] Option 2. The protected MEA according to Option 1, wherein:

[0032] A side peripheral portion of the cathode GDE layer forms at least a portion of the protective barrier.

[0033] Option 3. The protected MEA according to Option 2, wherein:

[0034] The side perimeter portion is bent upward relative to the inner portion of the cathode GDE layer so that the side perimeter portion is pressed against the subgasket bottom surface.

[0035] Option 4. The protected MEA according to Option 3, wherein:

[0036] The side perimeter portions are formed by removing sections of the membrane after the membrane has been attached to the cathode GDE layer.

[0037] Option 5. The protected MEA according to Option 4, wherein:

[0038] As part of the laser ablation process, the segments are removed from the film.

[0039] Embodiment 6. The protected MEA according to embodiment 4, wherein:

[0040] As part of the die cutting process, the segments are removed from the film.

[0041] Embodiment 7. The protected MEA according to embodiment 1, wherein:

[0042] A side peripheral portion of the membrane forms at least a portion of the protective barrier.

[0043] Embodiment 8. The protected MEA according to embodiment 7, wherein:

[0044] The side perimeter portions correspond to outer bands of the membrane that are offset by a channel from an inner portion of the membrane.

[0045] Embodiment 9. The protected MEA according to embodiment 8, wherein:

[0046] The channels do not comprise material of the membrane.

[0047] Embodiment 10. The protected MEA according to embodiment 8, wherein:

[0048] The channels are formed by removing sections of the membrane after it has been attached to the cathode GDE layer.

[0049] Embodiment 11. The protected MEA according to embodiment 10, wherein:

[0050] The segments are removed from the film as part of a laser ablation process or a die cutting process.

[0051] Scheme 12. A method for manufacturing a protected membrane electrode assembly (MEA) for a fuel cell, comprising:

[0052] receiving an anode gas diffusion electrode (GDE) layer having an anode top surface and an anode bottom surface;

[0053] receiving a cathode GDE layer having a cathode top surface and a cathode bottom surface;

[0054] receiving a membrane having a membrane top surface and a membrane bottom surface;

[0055] receiving a subgasket having a subgasket top surface and a subgasket bottom surface;

[0056] removing a membrane portion of the membrane to provide a protective barrier for protecting the membrane from external contaminants;

[0057] adhering the anode bottom surface to the subgasket top surface and the membrane top surface; and

[0058] The subgasket bottom surface is adhered to the membrane top surface such that the protective barrier surrounds a perimeter of the membrane between the subgasket bottom surface and the cathode top surface.

[0059] Solution 13. The method according to Solution 12 further includes:

[0060] The protective barrier is provided based at least in part on bending a cathode portion of the cathode GDE layer coincident with the membrane portion upward relative to an interior portion of the cathode GDE layer such that at least a portion of the cathode portion is pressed against the subgasket bottom surface.

[0061] Solution 14. The method according to Solution 12 further includes:

[0062] The protective barrier is provided by operating, at least in part, based on removing the membrane portion such that the membrane is separated into an outer membrane band and an inner membrane portion, the outer membrane band surrounding the inner membrane portion and offset from the inner membrane portion by a channel.

[0063] Solution 15. The method according to Solution 12 further includes:

[0064] After the membrane bottom surface has been adhered to the cathode top surface, the membrane portion is removed.

[0065] Solution 16. The method according to Solution 12 further includes:

[0066] The membrane portion is removed before the membrane bottom surface is adhered to the cathode top surface.

[0067] Embodiment 17. A protected membrane electrode assembly (MEA) for a fuel cell, comprising:

[0068] a first gas diffusion electrode (GDE) layer;

[0069] Second GDE layer;

[0070] Sub-gasket;

[0071] a film sandwiched between the first and second GDE layers and at least a surrounding subgasket portion of the subgasket; and

[0072] A protective barrier configured to protect the membrane from external contaminants surrounds a perimeter of the membrane between the peripheral subgasket portion and the second GDE layer.

[0073] Embodiment 18. The protected MEA according to embodiment 17, wherein:

[0074] The protection barrier is formed with a bent portion of the second GDE layer.

[0075] Embodiment 19. The protected MEA according to embodiment 17, wherein:

[0076] The protective barrier is formed with a channel shaped to separate the membrane into an outer membrane band and an inner membrane portion.

[0077] Embodiment 20. The protected MEA according to embodiment 17, wherein:

[0078] The protective barrier is formed by removing portions of the film.

[0079] These features and advantages, together with other features and advantages of the present teachings, may be apparent from the following detailed description of the mode for implementing the present teachings when considered in conjunction with the accompanying drawings. It should be understood that although the following drawings and embodiments may be described separately, their individual features may be combined into additional embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The accompanying drawings, which may be incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0081] Figure 1 A schematic diagram of a vehicle according to one non-limiting aspect of the present disclosure is shown.

[0082] Figure 2 A schematic diagram of a fuel cell system according to one non-limiting aspect of the present disclosure is shown.

[0083] Figure 3 An MEA manufacturing system according to one non-limiting aspect of the present disclosure is shown.

[0084] Figure 4 A cross-sectional view of an assembled MEA according to one non-limiting aspect of the present disclosure is shown.

[0085] Figure 5A cross-sectional view of a protected MEA according to one non-limiting aspect of the present disclosure is shown.

[0086] Figure 6 Another MEA manufacturing system according to one non-limiting aspect of the present disclosure is shown.

[0087] Figure 7 A cross-sectional view of another assembled MEA according to one non-limiting aspect of the present disclosure is shown. DETAILED DESCRIPTION

[0088] As desired, detailed embodiments of the present disclosure may be disclosed herein; however, it is understood that the disclosed embodiments may be merely examples of the present disclosure, which may be implemented in various and alternative forms. The drawings may not necessarily be drawn to scale, and some features may be exaggerated or minimized to show the details of particular components. Therefore, the specific structural and functional details disclosed herein may not be interpreted as limiting, but only as a representative basis for teaching those skilled in the art to implement the present disclosure in various ways.

[0089] Figure 1 A schematic diagram of a vehicle 10 according to one non-limiting aspect of the present disclosure is shown. The vehicle 10 may be configured with a propulsion system, a transmission, or other powertrain 12 having an electric motor 14 or other electric drive device operable to propel or otherwise drive the vehicle 10. For exemplary non-limiting purposes, the vehicle 10 may be shown as a hybrid type because the transmission 12 optionally includes an internal combustion engine (ICE) 16. The ICE 16 and the electric motor 14 or other device configured to convert electrical power into mechanical power may cooperate to provide rotational force / torque to one or more of a plurality of wheels 20, 22, 24, 26. The transmission 12 may include a transmission 34, a drive shaft 36, a differential 38, axles 40, 42, and / or other components to facilitate the transfer of rotational force from the ICE 16 and / or the motor 14 to the wheels 20, 22, 24, 26. The vehicle 10 may be illustrated as including a drive train 12 configured to connect the ICE 16 and the motor 14 to the front wheels 20, 24 for non-limiting purposes, as the present disclosure fully contemplates its use and application with four-wheel drive vehicles and other non-automotive types of vehicles. The controller 44 may be configured to generate control signals associated with directing and otherwise achieving desired control of the drive train 12, the motor 14, the ICE 16, and / or other features of the vehicle 10.

[0090] The vehicle 10 may be presented for non-limiting purposes as a representative of a wide variety of vehicles and / or other devices that may rely on converting electrical power into mechanical power. Such vehicles may be generally referred to as electric vehicles and include a wide variety of capabilities for supporting the conversion of electrical power into mechanical power. The vehicle 10 may be conceived to include different configurations for generating, storing, and supplying electrical power to the electric motor 14 and / or other devices or systems on the vehicle 10. One non-limiting aspect of the present disclosure relates to electrical power provided based at least in part on electrical power obtained from a fuel cell system 46. The fuel cell system 46 may be configured to generate electrical power by relying at least in part on an electrochemical reaction of a type suitable for generating electrical power. Figure 2 A schematic diagram of a fuel cell system 46 according to one non-limiting aspect of the present disclosure is shown. The system 46 may include one or more fuel cell stacks 48, each of which may be composed of a plurality of fuel cells 50, such as a polymer electrolyte membrane (PEM) fuel cell (PEMFC) type, which may be stacked and electrically connected in series or in parallel with each other. Each fuel cell 50 may be a multi-layer structure having an anode side 54 and a cathode side 56, which may be separated by a proton conducting membrane 58 (which may be referred to herein as a membrane 58).

[0091] An anode gas diffusion electrode (GDE) layer 60 may be disposed on the anode side 54 of the PEMFC, with an anode catalyst layer 62 mounted thereon or interposed therebetween for operatively connecting the membrane 58 and the corresponding GDE layer 60. Juxtaposed relative to the anode layers 60 and 62 in spaced relation may be a cathode GDE layer 64, which may be disposed on the cathode side 56 of the membrane 48. A cathode catalyst layer 66 may be mounted on the GDE layer 64, or interposed between and operatively connecting the membrane 58 and the corresponding GDE layer 64. The two GDE layers 60 and 64, the two catalyst layers 56 and 66, and the subgasket 68 cooperate with the membrane 58 to define a membrane electrode assembly (MEA) 70 in whole or in part. The GDE layers 60 and 64 may be porous structures that provide fluid inlet transport to and fluid exhaust transport from the MEA 70. An anode flow field plate 72 (with optional bipolar plate) may be disposed on the anode side 54 in abutting relation to the anode GDE layer 60. A cathode flow field plate 74 (with optional bipolar plate (BPP)) may be disposed on the cathode side 56 in abutting relation to the cathode GDE layer 64.

[0092] Coolant flow channels can be configured to traverse each plate 72 and 74 to allow cooling fluid to flow through the fuel cell 50. Fluid inlet ports and headers can guide hydrogen-rich fuel and oxidant to corresponding channels in the anode and cathode flow field plates 72, 74. The central active area of ​​the anode flow field plate 72 facing the proton conducting membrane 58 can be made with an anode flow field composed of serpentine flow channels for distributing hydrogen on the opposite surfaces of the GDE layer 60 and the membrane 58. The MEA 70 and the flow field plates 72, 74 can be stacked together between the collector plate and the monopolar end plate (not shown). The fuel cell system 46 can also use anode recirculation, where the anode recirculation gas can be supplied from the exhaust manifold or header through the anode recirculation line for recycling hydrogen back to the input of the anode side 54 so that the hydrogen is stored in the stack 48. A hydrogen (H 2 ) inlet flow (whether gaseous, condensed, entrained or otherwise) may be delivered from a hydrogen source (eg, fuel storage tank 46 ) to the anode side 54 of the fuel cell stack 48 via a fluid injector 47 coupled to a (first) fluid inlet conduit or hose.

[0093] The fuel cell stack 48 can be of a type commonly used in automotive-related applications, such as, but not necessarily limited to, a fuel cell stack 48 that can utilize a solid polymer electrolyte membrane (PEM) (also referred to as a "proton exchange membrane" (PEM)) to facilitate the electrolysis process by providing ion transport between the anode and cathode. A proton exchange membrane fuel cell (PEMFC) can use a solid polymer electrolyte (SPE) proton conducting membrane, such as a perfluorosulfonic acid membrane. The anode and cathode (not shown in detail) of the fuel cell stack 48 can include dispersed catalytic particles, such as platinum, supported on carbon particles and mixed with an ionomer. The catalytic mixture can be deposited on the side of the membrane to form an anode layer and a cathode layer. The combination of the anode catalyst layer, the cathode catalyst layer, and the electrolyte membrane can define an MEA 58, wherein the anode catalyst and the cathode catalyst can be supported on opposite surfaces of an ion-conducting solid polymer membrane. In order to avoid Fe2+ ions and / or other external contaminants from entering the membrane or interacting with the membrane so as to resist and potentially destroy the chemical structure of the membrane over time, a non-limiting aspect of the present disclosure contemplates protecting the MEA.

[0094] Figure 3Schematically illustrates an MEA manufacturing system 84 according to one non-limiting aspect of the present disclosure. The MEA manufacturing system 84 can be configured to manufacture an MEA 86 having a protective barrier 88. The protective barrier 88 can be used to protect the MEA 86, whereby the protective barrier 88 can be operable to prevent, minimize, hinder or otherwise limit the exposure of the membrane 90 to external contaminants. For example, the protective barrier 88 can be used in the manner described to limit the possibility or probability of Fe2+ ions and / or other external contaminants entering the membrane 90 or interacting with it so as to resist and potentially destroy the chemical structure of the membrane 90 over time. The protected MEA 86 can be configured to be used with a variety of GDE and non-GDE architectures, including but not limited to those used in other devices, vehicles, etc., so that the present disclosure fully contemplates that the protected MEA 86 can also be operated in other environments in addition to operating in the above-mentioned fuel cell 48 and / or fuel cell system 46. The protected MEA 86 is described with respect to the fuel cell system 46 in order to demonstrate the advantageous properties of the protected MEA 86 to protect the membrane 90 from external contaminants that may be particularly prevalent in the operating setting of the vehicle 10 .

[0095] The MEA manufacturing system 84 may include an anode roll 92 having a supply of material suitable for forming an anode GDE layer 94. The anode GDE layer 94 may be produced in part based on cutting, separating, extracting or otherwise recovering the anode GDE layer 94 from the anode roll 92. For non-limiting purposes, this is shown with respect to a stamping, laser or die-cutting tool or operation 96, which may be operated to cut the anode GDE layer 94 into a desired shape and configuration once it is unrolled from the anode roll 92. Alternatively, the anode GDE layer 94 may be provided by other mechanisms and / or as a cut-to-shape component having a desired shape, size, configuration, etc. The protected MEA 86 manufacturing system may include a cathode roll 100 having a supply of material suitable for forming a cathode GDE layer 102, which is shown as including a membrane 90 integrated therewith, i.e., included as part of the material supplied by the cathode roll 100. The cathode GDE layer 102 and the film 90 may be produced based in part on cutting, separating, extracting or recovering the cathode GDE layer 102 from the cathode reel 100. For non-limiting purposes, this is described with respect to a stamping, laser or die-cutting tool or operation 104, which is operable to cut the cathode GDE layer 102 and the film 90 together into a desired shape and configuration as they are unwound from the cathode reel 100. Alternatively, the cathode GDE layer 102 may be provided by other mechanisms, the film 90 layer may be wound or provided separately, and / or the cathode layer and / or the film 90 may be received as a cut-to-shape component having a desired shape, size, configuration, etc.

[0096] Once the anode GDE layer 94, cathode GDE layer 102, and membrane 90 can be cut to size, the MEA manufacturing system 84 may include a protective barrier tool 106 that is operable to perform a barrier protection process so that a portion of the protective barrier 88 can be added. In the illustrated configuration, the protective barrier 88 can be added by removing a membrane portion 108 of the membrane 90, that is, the protected barrier 88 can correspond to a portion 110 of the cathode GDE layer 102 that overlaps with the membrane portion 108 removed from the membrane 90. For example, the protective barrier tool 106 can be configured to support a laser ablation process, a die cutting process, or other removal processes suitable for removing the membrane portion 108 from the membrane 90 adhered to the cathode GDE layer 102. The membrane portion 108 removed from the membrane 90 can cause the membrane 90 to have a smaller footprint than before the removal process. The MEA manufacturing system 84 may include an assembly process 112 for assembling the cathode GDE layer 102, the membrane 90, the subgasket 114, and the anode GDE layer 94 together. Subgasket 114 may be used to provide sealing and other protection for membrane 90 and may be provided from a reel (not shown) or other mechanism, such as as sheets cut to appropriate size.After assembly process 112, a final assembled MEA 116 may be provided.

[0097] Figure 4 Schematically illustrated is a cross-sectional view of an assembled MEA 116 according to one non-limiting aspect of the present disclosure. The assembled MEA 116 may include a cathode GDE layer 102, a membrane 90, a subgasket 114, and an anode GDE layer 94. The cathode GDE layer 102 may include a cathode catalyst layer 118, and the anode GDE layer 94 may include an anode catalyst layer 120. The subgasket 114 may include an upper portion 124 and a lower portion 126 held together by a bond or other bonding element 128. For non-limiting purposes, an exemplary depiction of the assembled MEA 116 is shown, as the present disclosure fully contemplates assembled MEAs 116 including additional layers, components, etc., as well as including fewer layers, components, etc. Anode GDE layer 94 may include anode top surface 132 and anode bottom surface 134, cathode GDE layer 102 may include cathode top surface 136 and cathode bottom surface 138, membrane 90 may include membrane top surface 142 and membrane bottom surface 144, wherein membrane 90 bottom surface is attached to cathode top surface 136, and subgasket 114 may include subgasket top surface 146 and subgasket bottom surface 148, wherein subgasket bottom surface 148 is attached to membrane top surface 142, and subgasket top surface 146 is attached to anode bottom surface 134. Separation 150 between subgasket 114 and cathode GDE layer 102 may result in the formation of a window between membrane 90 and the external environment.

[0098] The cathode GDE layer 102 may include a side perimeter portion 152 adjacent to the window that overhangs or extends beyond a perimeter 154 of the membrane 90. The side perimeter portion 152 may surround the entire perimeter 154 of the membrane 90 between the subgasket bottom surface 148 and the cathode top surface 136. One non-limiting aspect of the present disclosure contemplates utilizing the side perimeter portion 152 to provide a protective barrier 88 for the membrane 90. Return to Figure 3 , a protective barrier 88 may be provided by bending the side perimeter portion 152 upward relative to the inner portion 156 of the cathode GDE layer 102 so that the side perimeter portion 152 is pressed against the subgasket bottom surface 148. The bending process 162 of the MEA manufacturing system 84 may include a tool or other process for bending the cathode GDE layer 102 in a desired manner to provide a protected MEA 86. The bending process 162 may include stamping, pressing or other physical means to force the side perimeter portion 152 to press against the subgasket 114 and optionally seal with the subgasket 114. The bending process 162 may optionally include a heating element or other process, such as etching, etc., to facilitate bending the cathode GDE layer 102 and / or the use of adhesives, sealants, etc. to further ensure a tight seal between the subgasket 114 and the cathode GDE layer 102.

[0099] Figure 5 Schematically illustrates a cross-sectional view of a protected MEA 86 according to one non-limiting aspect of the present disclosure. The bending process 162 may be beneficial in pressing the side perimeter portion 152 of the GDE layer 102 against the subgasket 114, which may result in a slight gap 164 between the edge of the membrane 90 and the sealing interface 164 between the subgasket 114 and the cathode GDE layer 102. The protective barrier 88 may be used in this manner to prevent external contaminants from passing through the protective barrier 88. Figure 4 The window 150 shown reaches the film 90. The removal of the film portion 108 and the bending of the cathode GDE layer 102 can cause the film 90 and the cathode GDE layer 102 to have a slightly shorter or narrower profile relative to the removal and bending process. This narrowing can be compensated by shaping the film 90 and / or the cathode GDE layer 102 to be correspondingly larger or wider to anticipate the narrowing. The resulting protective barrier 88 can be operable to avoid or limit Fe2+ ions and / or other external contaminants to enter the film 90 or interact with the film 90 so as to resist and potentially destroy the chemical structure of the film 90 over time. Optionally using the cathode GDE layer 102 and slightly removing a portion of the section 110 of the film 90, the ability to provide the protective barrier 88 can be beneficial to protecting the film 90 from the influence of external contaminants without having to add additional components, devices, etc. outside the components, devices, etc. that have been included as a part of the MEA.

[0100] Figure 6Another MEA manufacturing system 170 according to one non-limiting aspect of the present disclosure is schematically shown. The MEA manufacturing system 170 may be configured to manufacture an MEA 172 having another type of protective barrier 174. The MEA manufacturing system 170 may include an anode reel 92, a cathode reel 100, forming tools 96, 104, and related processes as described above. Once the anode GDE layer 94, the cathode GDE layer 102, and the membrane 90 can be cut to size, the MEA manufacturing system 170 may include a protective barrier tool 178, which is operable to perform a barrier protection process so that the protective barrier 174 can be added. In the configuration shown, the protective barrier 174 can be added by removing a membrane portion 180 of the membrane 90, that is, the protected barrier 174 can correspond to a portion of the cathode GDE layer 102 that overlaps with the membrane portion 180 removed from the membrane 90. For example, the protective barrier tool 178 can be configured to support a laser ablation process, a die cutting process, or other removal process suitable for removing the membrane portion 180 from the membrane 90 adhered to the cathode GDE layer 102. The removal of the membrane portion 180 can result in the membrane 90 being separated into an outer membrane band 182 and an inner membrane portion 184, wherein the outer membrane band 182 surrounds the inner membrane portion 184 and is offset from it by a channel 186. The MEA manufacturing system 170 can include an assembly process 112 for assembling the cathode GDE layer 102, the membrane 90, the subgasket 114, and the anode GDE layer 94 together.

[0101] Figure 7 Schematically illustrates a cross-sectional view of a protected MEA 172 according to one non-limiting aspect of the present disclosure. The MEA 172 may include a cathode GDE layer 102, a membrane 90, a subgasket 114, and an anode GDE layer 94. Using a protective barrier 174 to provide a channel 186 between an outer membrane strip 182 and an inner membrane portion 184 may allow the outer membrane strip 182 to operate as a sacrificial component. The outer membrane strip 182 may be used in this manner to create a chemical agent barrier 174 that may interact with external contaminants to prevent those contaminants from effectively reaching the inner membrane portion 184. The size, shape, width of the outer membrane strip 182 and / or the channel 186 may be design parameters that vary depending on the material properties of the associated components. While the present disclosure fully contemplates the inclusion of additional sealants or materials to operate in conjunction with the protective barrier 174, the ability to provide a protective barrier 174 without using such additional features may be advantageous in being able to sort external contaminants to prevent them from reaching the membrane 90 without adding additional components, devices, etc. to components, devices, etc. that are already included as part of the MEA. While the protective barrier 174 is described with respect to being formed within the film 90 using a laser or die cutting process, the present disclosure fully contemplates other mechanisms for creating the outer film 90 band, such as melting or passivating the film 90 edge rather than completely ablating it.

[0102] As described above, the present disclosure relates to the use of lasers (e.g., femtosecond and nanosecond pulsed lasers, etc.) to manufacture MEAs, which may include cutting a membrane layer without damaging the underlying GDE, and then cutting the remaining GDE at a certain position so that the cut edge of the GDE layer extends beyond the cut edge of the membrane layer. The resulting layer structure combination of the membrane and the GDE can be further combined with a second GDE and laminated to form an MEA, wherein the resulting MEA has excellent resistance to chemical degradation of the membrane layer. The MEA can be constructed so that the outer edge of the membrane is protected by the GDE. Using laser technology to selectively ablate the surface of the GDE and the membrane at a specific position and depth can achieve layer structures of different sizes without the need for additional assembly methods or complex cutting processes. In one aspect, selective surface ablation can be performed at the edge of the GDE with a membrane to eliminate the path of contaminants, for example, laser ablation with a depth of about 20 μm and a desired width can be performed. On the other hand, laser ablation can be used to remove the membrane below the sub-gasket and a few microns away from the edge to form a groove-shaped design. The present disclosure can enable mass production of MEAs with design features intended to extend the durability of the MEA (particularly the membrane life) by limiting the path for life-limiting contaminants to reach the membrane. The use of laser methods can reduce the cycle time required for trimming components, combined with the design features required to extend the life of the MEA, optionally avoiding complex fixed and discontinuous assembly processes. This design and method can also enable mass production processes for roll-to-roll laminated membranes and advanced coating membranes on electrodes. The present disclosure can allow process equipment to utilize a more maintainable solution that does not have significant maintenance costs, such as replacement or durability of cutting methods, for example, laser cutting can have much higher precision and quality of manufactured parts over time because there is less tool wear.

[0103] The terms "comprise", "include" and "have" are inclusive and therefore specify the presence of the features, steps, operations, elements or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements or parts. The order of steps, processes and operations can be changed when possible, and additional or alternative steps can be adopted. As used in this specification, the term "or" includes any one and all combinations of the relevant listed items. The term "any of..." should be understood to include any possible combination of the cited items, including "any one" of the cited items. "One", "one", "the", "at least one" and "one or more" are used interchangeably to indicate that there is at least one of the items. Unless the context clearly indicates otherwise, there may be multiple such items. Unless otherwise clearly or clearly indicated in the context (including the attached claims), all parameter values ​​(e.g., the value of quantity or condition) should be understood to be modified by the term "about" in all cases, whether or not "about" actually appears before the value. A component "configured to" perform a specified function is able to perform the specified function without making changes, rather than having the potential to perform the specified function only after further modification. In other words, when explicitly configured to perform a specified function, the hardware is specifically selected, created, implemented, utilized, programmed and / or designed for the purpose of performing the specified function.

[0104] Although various embodiments have been described, the description is intended to be exemplary rather than restrictive, and it will be apparent to those of ordinary skill in the art that more embodiments and implementations within the scope of the embodiments are possible. Unless specifically limited, any feature of any embodiment may be used in combination with any other feature or element in any other embodiment or replace any other feature or element in any other embodiment. Therefore, the embodiments are not limited except according to the attached claims and their equivalents. Moreover, various modifications and changes may be made within the scope of the attached claims. Although several modes for performing many aspects of the present teachings have been described in detail, those skilled in the art in the field to which these teachings are related will recognize various alternative aspects for practicing the present teachings, which fall within the scope of the attached claims. It is intended that all of the content contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and exemplary for the entire scope of alternative embodiments, and those skilled in the art will recognize that these alternative embodiments are implied by the included content, structurally and / or functionally equivalent to the included content, or become apparent in other ways based on the included content, and should not be limited to only those embodiments that are explicitly depicted and / or described.

Claims

1. A protected membrane electrode assembly (MEA) for a fuel cell, comprising: an anode gas diffusion electrode (GDE) layer having an anode top surface and an anode bottom surface; a cathode GDE layer having a cathode top surface and a cathode bottom surface; a membrane having a membrane top surface and a membrane bottom surface, wherein the membrane bottom surface is attached to the cathode top surface; a subgasket having a subgasket top surface and a subgasket bottom surface, wherein the subgasket bottom surface is attached to the membrane top surface and the subgasket top surface is attached to the anode bottom surface; as well as A protective barrier configured to protect the membrane from external contaminants surrounds a perimeter of the membrane between the subgasket bottom surface and the cathode top surface.

2. The protected MEA according to claim 1, wherein: A side peripheral portion of the cathode GDE layer forms at least a portion of the protective barrier.

3. The protected MEA of claim 2, wherein: The side perimeter portion is bent upward relative to the inner portion of the cathode GDE layer so that the side perimeter portion is pressed against the subgasket bottom surface.

4. The protected MEA of claim 3, wherein: The side perimeter portions are formed by removing sections of the membrane after the membrane has been attached to the cathode GDE layer.

5. The protected MEA of claim 4, wherein: As part of the laser ablation process, the segments are removed from the film.

6. The protected MEA of claim 4, wherein: As part of the die cutting process, the segments are removed from the film.

7. The protected MEA of claim 1, wherein: A side peripheral portion of the membrane forms at least a portion of the protective barrier.

8. The protected MEA of claim 7, wherein: The side perimeter portions correspond to outer bands of the membrane that are offset by a channel from an inner portion of the membrane.

9. The protected MEA of claim 8, wherein: The channels do not comprise material of the membrane.

10. The protected MEA of claim 8, wherein: The channels are formed by removing sections of the membrane after it has been attached to the cathode GDE layer.

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