Integrated circuit for diagnosis

Abstract

The fuel cell system includes a membrane electrode assembly, a first plate separator and a second plate separator located on opposite sides sandwiching the membrane electrode assembly. The first plate separator and the second plate separator have outer ends at positions away from the membrane electrode assembly. A first gas diffusion layer is located between the first plate separator and the membrane electrode assembly. A second gas diffusion layer is located between the second plate separator and the membrane electrode assembly. A sub gasket extends laterally from the membrane electrode assembly toward at least one of the outer ends. A first seal is located between the first plate separator and the sub gasket. A conductive trace is attached to the sub gasket and extends on the sub gasket from the outside of the first seal to the inside of the first seal.

Description

Cross - reference to related applications

[0001] This application is related to U.S. Patent Application No. 17 / 572,679 (Attorney Docket No. 1404.332), filed on January 11, 2022, entitled "FUEL CELLL STACK AND METHOD FOR MANUFACTURE", the disclosure of which is incorporated herein by reference.

Technical Field

[0002] The present invention generally relates to methods and systems for monitoring a fuel cell stack, and more specifically to systems and methods for monitoring a fuel cell stack for variations in the electrical output and operating conditions of fuel cells in a fuel cell stack system.

Background Art

[0003] Fuel cells electrochemically convert fuel and an oxidant into electricity and heat, and can be classified according to the type of electrolyte used to effect ion movement during operation (e.g., solid oxide, molten carbonate, alkaline, phosphoric acid, or solid polymer). Further, fuel cell assemblies can be used in numerous environments (e.g., automotive - aerospace - industrial - residential) for a number of applications.

[0004] A proton exchange membrane (hereinafter referred to as "PEM" in this specification) fuel cell directly converts the chemical energy of a fuel such as hydrogen and an oxidant such as air into electrical energy. The PEM is a sold polymer electrolyte that allows protons (i.e., H+ ions) to pass from the "anode" side of the fuel cell to the "cathode" side of the fuel cell while preventing the passage of reactant fluids (e.g., hydrogen gas and air gas). A membrane - electrode assembly (hereinafter referred to as "MEA" in this specification) is positioned between two conductive plates, each having flow channels that direct fuel to the anode side of the PEM and an oxidant to the cathode side.

[0005] It is possible to connect two or more fuel cells to each other to increase the overall power output of the assembly. Generally, the cells are connected in series, in which case one side of the plate serves as the anode plate of one cell, and the opposite side of the plate is the cathode plate of the adjacent cell. These are generally referred to as bipolar plates (hereinafter referred to as "BPPs" in this specification). Alternatively, the anode plate of one cell is electrically connected to a separate cathode plate of an adjacent cell. Generally, these two plates are connected back-to-back and are often adhered to each other (e.g., adhered by an adhesive, welding, or a polymer). This adhered pair becomes integral and is also often referred to as a bipolar plate because the anode plate and the cathode plate electrically correspond to the positive and negative electrodes, respectively. Such a continuously connected number of fuel cells is called a fuel cell stack. The stack typically includes means for directing fuel and oxidant to the flow field channels of the anode and cathode, respectively. The stack usually includes means for directing a coolant fluid into internal channels within the stack to absorb heat generated by the exothermic reaction of hydrogen and oxygen within the fuel cell. The stack generally includes means for discharging not only the generated water but also excess fuel gas and oxidant gas.

[0006] The stack further includes, among other components, end plates, insulators, membrane electrode assemblies, gaskets, separator plates, electrical connectors, and collector plates, which are integrated to form a functioning stack designed to generate electricity. The various plates can be brought into contact with each other and connected to each other to facilitate the performance of specific functions.

[0007] As described above, the fuel cell stack includes a number of connected fuel cells. Monitoring of the individual cell voltages is important for system control and durability. For example, if low-performance cells are not detected, they can cause numerous failure mechanisms. Large stacks of fuel cells can sometimes contain hundreds of cells, and the cell voltages of such cells are currently detected using individual wires where the voltage signals are multiplexed by an external circuit. Management of these wires and their connections is time-consuming and cumbersome when assembling a large number of fuel cells into a fuel cell stack, and there are significant voltage differences that must be managed within the electronic device.

[0008] Therefore, an improved system and method for interconnecting the various parts of a fuel cell system are needed.

SUMMARY OF THE INVENTION

[0009] In a first aspect, the present invention provides a fuel cell system comprising a membrane electrode assembly, a first plate separator and a second plate separator located on opposite sides sandwiching the membrane electrode assembly. The first plate separator and the second plate separator have outer ends at positions remote from the membrane electrode assembly. A first gas diffusion layer is located between the first plate separator and the membrane electrode assembly. A second gas diffusion layer is located between the second plate separator and the membrane electrode assembly. A sub-gasket extends laterally from the membrane electrode assembly towards at least one of the outer ends. A first seal is located between the first plate separator and the sub-gasket. A conductive trace is attached to the sub-gasket and extends on the sub-gasket from the outside of the first seal to the inside of the first seal.

[0010] In a second aspect, the present invention provides a method for use in manufacturing a fuel cell system, the method including the step of attaching a conductive trace to a sub-gasket. The membrane electrode assembly is positioned on the sub-gasket such that a lateral portion of the sub-gasket extends away from the membrane electrode assembly and toward the exterior of the fuel cell assembly. A first gas diffusion layer is positioned on a first side of the membrane electrode assembly, and a second gas diffusion layer is positioned on a second side of the membrane electrode assembly. The conductive trace is attached to the sub-gasket and extends across the sub-gasket between the seal and from the interior of the fuel cell assembly past the seal and toward the exterior of the fuel cell assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Subject matter regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of this specification. The foregoing and other features and advantages of the invention will be apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings.

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[0029] The present invention will be discussed in detail below with respect to various exemplary embodiments according to the present invention with reference to the accompanying drawings. In the following detailed description, numerous specific details are set forth for a complete understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures are not shown in detail to avoid unnecessarily obscuring the present invention.

[0030] Accordingly, all of the implementations described below are exemplary implementations provided to enable those skilled in the art to make or use the embodiments of the present disclosure, and are not intended to limit the scope of the present disclosure defined by the claims. As used herein, the terms "exemplary" or "illustrative" mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" or "illustrative" should not necessarily be construed as more preferred or advantageous than other implementations. Further, in the description of this section, the terms "above", "below", "left", "rear", "right", "front", "vertical", "horizontal", and derivatives thereof shall relate to the orientation of the present invention in FIG. 1.

[0031] Furthermore, there is no intention to be bound by any theory, whether explicit or implicit, presented in the foregoing technical fields, background, summary, or detailed description below. It should also be understood that the specific devices and processing procedures illustrated in the accompanying drawings and described in the following specification are merely exemplary embodiments of the concepts of the present invention defined in the appended claims. Therefore, specific dimensions and other physical characteristics related to the embodiments disclosed herein should not be considered limiting unless otherwise explicitly specified in the claims.

[0032] In accordance with the principles of the present invention, a fuel cell system and a method for manufacturing a fuel cell stack are provided. In the example shown in FIG. 1, the fuel cell system 101 is referred to as an assembly system or a complete system, which produces electricity together with all its components in function and typically includes a fuel cell stack 20 and an energy storage device 30. Fuel 13, such as hydrogen, is supplied to the fuel cell through a fuel inlet 17. Excess fuel 18 may be discharged from the fuel cell through a purge valve 90 and may be diluted by a blower 40. In one example, the fuel cell stack 20 may have an open cathode structure of a PEM fuel cell, and a combination of an oxidant and a coolant, such as air, can enter through an inlet air filter 10 coupled to an inlet 5 of the fuel cell stack 20. Excess coolant / oxidant and heat are discharged from the fuel cell cathode of the fuel cell stack 20 to the blower 40 through an outlet 11, and the blower can discharge the coolant / oxidant and / or excess fuel to an exhaust 41, such as the ambient atmosphere. The fuel and the coolant / oxidant can be supplied by a fuel supply source 7 and an oxidant supply source 9 (such as air), respectively, and by other components of the peripheral equipment that may include compressors, pumps, valves, blowers, electrical connections, and sensors. In other examples, it is also conceivable to use a separate liquid coolant to separate the aforementioned oxidant and coolant.

[0033] Figure 2 is a schematic exploded assembly view showing the internal sub-assembly 100 of the fuel cell stack 20 of FIG. 1, which includes a cathode plate separator 110 at the outer end 115 and a plate separator seal 120 inside thereof. The membrane electrode assembly (MEA) 130 is located between the seal 120 and the second plate separator seal 150. The anode plate separator 160 is at the second end 165 of the sub-assembly 100.

[0034] The MEA 130 includes a membrane 140 (e.g., an ion conductive membrane) between a cathode-side catalyst layer 125 and an anode-side catalyst layer 135. The cathode-side gas diffusion layer (GDL) 122 is located between the cathode-side catalyst layer 125 of the membrane electrode assembly and the plate separator 110. The anode-side gas diffusion layer 145 is located between the anode-side catalyst layer 135 of the membrane electrode assembly and the plate separator 160. The seals 120 and 150 may be received in channels inside the plate separator 110 and the plate separator 160, respectively. In another example, such seals may be injection molded around the MEA (e.g., MEA 130) or another fuel cell to provide a sealing function, such as between the MEA and the fuel cell plate separator.

[0035] Figure 3 shows an exploded assembly view similar to FIG. 2, except that the seals (i.e., seal 120 and seal 150) are omitted and the cathode plate separator 110 is omitted for clarity of the repeating portion 103 of the internal sub-assembly 100. A seal or sub-gasket 300 is located between the cathode-side catalyst layer 125 and the anode-side catalyst layer 135 with the MEA 130 received in the cavity 146 of the sub-gasket 300. A gasket or seal 170 may be located under the plate separator 160.

[0036] As described above, the MEA 130 can be received in the opening 146 of the sub-gasket 300 that can be formed of a non-conductive material such as a polymer. As shown in the figure, the MEA 130 can be attached to the anode-side GDL 145 (e.g., by a thermosensitive adhesive), and the combined MEA 130-GDL 145 can be sandwiched between the GDLs 122 around the sub-gasket 300 so that the components adhere to each other. For example, this combination may be formed by hot compressing the aligned anode and cathode portions (e.g., MEA 130-GDL 145 and GDL 122) so that these portions adhere to the sub-gasket 300. In one example, a heated platen holds the gas diffusion layers (gas diffusion layer 122, gas diffusion layer 145) and the membrane electrode assembly 130, and adhesion to the sub-gasket 300 (e.g., via a thermosensitive adhesive or via adhesion of the gas diffusion layer to the MEA) may be performed therebetween.

[0037] In the example shown in FIG. 4, the sub-assembly 100 includes opposing bipolar plates 102 (e.g., plate separator 110 and plate separator 160), and each of the plates may be connected to one of the wires 3 for connection to a control device or sensor for purposes such as monitoring and / or control.

[0038] In the example shown in FIG. 5, the metal trace 200 can be connected to the GDLs (e.g., GDL 122 and GDL 145) on both sides of the membrane (e.g., membrane 140). As shown in the figure, the first upper trace 205 of the trace 200 is attached to and positioned on the first side (e.g., the upper side in the drawing) 301 of the sub-gasket 300, while the second lower trace 207 is attached to and positioned on the second side 302 and can extend through the sub-gasket vertically (e.g., through a via) to the first side 301. The metal trace (e.g., trace 200) can be printed on the sub-gasket (e.g., sub-gasket 300) during a metallization printing process or by another method of depositing a metal or other conductive strip or trace on the gasket (e.g., vacuum metallization, arc spraying or flame spraying, plating). After an opening or via through the sub-gasket is provided, a metal material or other conductive material can be printed or otherwise positioned in the opening to form a metallized via, and the lower trace (e.g., the second trace 207) may be capable of having an upward extension 203 that extends through the gasket (e.g., gasket 300).

[0039] The trace 200 includes an electrical connector 201 (e.g., formed of a conductive metal or the same material as the trace 200) at an end opposite to the GDLs (e.g., GDL 122 and GDL 145), enabling the trace (e.g., trace 200) and thus the GDL to be electrically connected to one or more control devices, sensors, or other devices external to the sub-assembly 100. For example, the trace can be connected to a voltage sensor or a computerized control device.

[0040] As described above, the trace 200 can be connected to a GDL (e.g., GDL 122 and GDL 145) so as to electrically connect between the GDL and the connector 201, enabling an external connection to the GDL for the purpose of monitoring and / or controlling the sub-assembly 100 and the fuel cell stack 20. For example, the sub-gasket 300 and the trace 200 can extend from the GDL 122 and / or the GDL 145 toward the outside of the sub-assembly 100. For example, the sub-gasket 300 and the trace 200 can extend outwardly past the outermost or outer end 111 of the plate separator 110 and / or the outermost or outer end 161 of the plate separator 160. It is also conceivable that the connector 201 is located outside the outer end 111 and / or the outer end 161 as shown in the figure. By positioning the connector outside the plate separator and the seal 120 and / or the seal 150, (since it is located outside), it becomes possible to further space it apart, enabling the connector to be easily connected by an external device such as a sensor and a control device.

[0041] FIG. 6 shows a part of FIG. 5 including a portion of the upper trace 205, the plate separator 110, the GDL 122, the membrane 140, and the sub-gasket 300. The upper trace 205 extends between the sub-gasket 300 and the seal or gasket 120 and is received under the GDL 122 and above the sub-gasket 300. More specifically, the GDL-side end 206 of the upper trace 205 on the opposite side of the connector 201 can contact and be connected to the GDL 122 so as to provide an electrical connection between the GDL 122 and the first connector 202 (FIG. 5) of the connector 201 by providing a connection between the GDL 122 and the upper trace 205. The second trace 207 can extend between the sub-gasket 300 and the seal or gasket 150 and be received under the GDL 145 and above the sub-gasket 300, for example, as shown in FIG. 5. Further, the second trace 207 can extend through the sub-gasket as described above.

[0042] In another example shown in FIG. 7, the first trace 205 can include a spike 210 extending in a vertical direction at or near the end 211 of the trace 205 to allow the trace 205 to penetrate deeper into the GDL 122 compared to the laterally extending portion 212 and the end 211 of the trace 205. The spike 210 extends into the GDL 122 (but preferably does not extend through the GDL 122 and into the plate separator 110), and can improve the electrical connection of the trace 205, and thus the connector 202, to the GDL 122 (due to the larger surface area and larger dimensions). The first trace 205 having the spike 210 can be formed by depositing (e.g., printing) additional metal or other conductive material on the trace 205 to form the spike 210 during or in a subsequent step of forming the first trace 205. For example, the spike 210 may be formed by stamping the metallized plastic forming the trace 205. Additionally, the spike 210 may be formed by bending and cutting such metallized plastic. The second trace 207 (not shown in FIG. 7) can extend between, for example, the sub-gasket 300 and the seal or gasket 150 and be received under the GDL 145 and above the sub-gasket 300, as shown in FIG. 5. Further, the second trace 207 can extend through the sub-gasket as described above.

[0043] In yet another example shown in FIG. 8, it is possible to use trace 208 instead of the first trace 205 compared to the above description, and the upward extension portion 209 of the trace 208 extends upward from the portion 204 of the trace 208 connected to the sub gasket 300 at a lateral position with respect to the GDL 122, so that the trace 208 may not extend between the gasket 120 and the sub gasket 300. The upwardly extending portion 209 of the trace 208 may be formed by the method described for the spike 210 and may extend upward and contact the plate separator 110. In contrast to the above description, a second trace (not shown) may be used instead of the second trace 207, and may be positioned to extend along the opposite side of the sub gasket 300 perpendicular to the trace 208, and may similarly extend downward and contact the plate separator 160. Such a second trace may also be considered to extend through the sub gasket 300 similar to the trace 207.

[0044] In the example shown in FIGS. 9 - 10, similar to that described above with respect to the sub - gasket 300, MEA 130, and trace 205, the sub - gasket 305 is connected to the MEA 330, and the trace 310 can be received on the sub - gasket 130. Further, the sub - gasket 305 includes a protruding tab 340, and the trace 310 can extend from a GDL 312 similar to the above - mentioned GDL 122 and GDL 145. Further, a second trace (not shown) may be located on the opposite side of the sub - gasket 305 similar to the above - mentioned trace 207. A connector 350 is positioned on the sub - gasket 305 (e.g., tab 340) and connected to the trace, and it may be possible for an external device (e.g., a voltage sensor or an electronic control unit) to be connected to the trace and thus to a GDL (not shown) on both sides of the MEA. The tab 340 extends away from the rest of the gasket 305 and the fuel cell stack (e.g., fuel cell stack 20) and can have a longitudinal dimension (along with its lateral dimension) sized such that the connector 350 can be spaced from the outer surface or casing of the sub - assembly (e.g., sub - assembly 100) or the fuel cell stack (e.g., fuel cell stack 20). By spacing it in such a way, it is possible to facilitate connection to the device and / or to facilitate the operation of the device connected to the connector. Further, the tab 340 can have a lateral width dimension shorter than the above - mentioned longitudinal dimension, which allows a plurality of such tabs to be positioned adjacent to each other laterally to facilitate a multi - connection with various fuel cells or other components of the fuel cell stack (e.g., fuel cell stack 20).

[0045] Figures 11-12 show a plurality of sub-gaskets 500 similar to the sub-gasket 305, each sub-gasket having tabs 510 (similar to tab 340) that are at different positions along the longitudinal dimension of the gasket (whose edges are aligned) and the accompanying sub-assembly or fuel cell stack (e.g., fuel cell stack 20), i.e., are positioned side by side with respect to each other. As described above, the tabs being positioned side by side with respect to each other enables easy connection to a plurality of devices (e.g., sensors or control devices) along the longitudinal dimension of the gasket, and provides space for connection to such devices (e.g., by extending the tabs longitudinally from the remainder of the fuel cell stack and the tabs being positioned side by side with respect to each other), and / or enables provision of space between the tabs and the devices so that the devices can function better.

[0046] Figure 13 shows an alternative sub-gasket 550, which is similar to the above-described sub-gaskets (e.g., sub-gasket 300, sub-gasket 305, sub-gasket 500) except that a plurality of conductive traces are attached by metallization printing or other deposition. For example, the sub-gasket 550 can include traces 560 that extend to various positions along the sub-gasket 550 and enable electrical connection between such positions and connectors 570 that are positioned at tabs 580 similar to the above-described tabs (e.g., tab 340, tab 510). Further, such traces (e.g., trace 560) can lead from the tabs 580 to sensors or other devices that are positioned on or adjacent to the sub-gasket 550.

[0047] FIG. 14 is identical to FIG. 5 except that a device 600 is connected to the connector 201 of the sub-assembly 100. In one example, the device 600 may be a voltage sensor. By connecting traces (e.g., trace 205, trace 207) to GDLs (e.g., GDL 122 and GDL 145), such a sensor can measure the voltage across a membrane (e.g., membrane 140) of 0.6 - 0.9V when the circuit thus formed is powered by a fuel cell (e.g., sub-assembly 100) and is operating properly, for example. An example of a voltage sensor that can be used with the sub-assembly described above is described in U.S. Patent Application No. _____ (Attorney Docket No. 1404.333) by the same applicant. The device 600 may also be an electronic control device, a temperature sensor, or other device for monitoring a fuel cell stack (e.g., fuel cell stack 20).

[0048] In the example shown in FIGS. 15 - 16, the sub-gasket 650 includes a first trace 660 and a second trace 670 formed of different types of metal, such that a difference in temperature creates a thermocouple junction 680 by causing a change in potential. More specifically, the second trace 670 can be overlapped with the first trace 660 and the thermocouple junction 680 so that a change in temperature is sensed by an electrical connection between the first trace and the second trace. As shown in FIG. 16, a seal 690 may electrically insulate the thermocouple junction 680 from the GDL 122. In one example, an increase or decrease in temperature may be sensed by an electrical connection between the first trace 660 and / or the second trace 670 and the GDL 122.

[0049] As shown in FIG. 17, device 700 can be electrically connected to tabs (e.g., tab 340, tab 510, FIGS. 11-12) of a plurality of fuel cells of a fuel cell stack (e.g., fuel cell stack 2). By connecting to a plurality of fuel cells within the stack in this way, sufficient power can be provided to power a device such as device 700 that can be used for measuring the status of a fuel cell stack, controlling components of the stack (e.g., a motor or peripheral devices), or providing other necessary functions. Similarly, it is also conceivable to use a device such as device 700 for measuring a stack that is powered by a stack at a higher potential.

[0050] In an example not shown, it is also conceivable that the tabs (e.g., tab 340, tab 510) have an outermost edge or side edge that is conductive (e.g., a conductive material such as metal may be printed or deposited in another way on top) and can be connected to traces (e.g., traces 205, 208, 208, 310, 560) as described above that can be connected to internal elements of a fuel cell stack (e.g., fuel cell stack 20). Such conductive tabs can be vertically aligned to enable electrical connection between tabs that enable electrical connection between vertical or horizontal portions of a fuel cell stack (e.g., a fuel cell stack) to facilitate connection of sensors and / or control devices to various parts of the stack as described above.

[0051] Fuel cell subassembly 100 can be manufactured using a method based on using a web sheet or plastic sheet for connecting components during the manufacture of a fuel cell stack (e.g., fuel cell stack 20) as described in U.S. Patent Application No. 17 / 572,679 filed on January 11, 2022 by the same applicant. As another example, the manufacture of assembly 100 and its parts may be performed manually or may be a combination of the above-described automated method and the manual method.

[0052] The above examples of conductive traces (e.g., trace 200, trace 205, trace 207, trace 208, trace 310, trace 560) refer to traces that are printed on, positioned by deposition or other means, connected to, or adjacent to the plate separator 110, the GDL 122, and the membrane 140. However, the methods of connecting such traces can be utilized with other plate separators, GDLs, and systems described herein. For example, such a trace may be installed on another sub-gasket connected to the MEA in a number of fuel cells of a fuel cell stack (e.g., fuel cell stack 20).

[0053] Although some aspects of the present invention have been described and illustrated herein, those skilled in the art may adopt alternative aspects to achieve the same purpose. Accordingly, it is intended that the appended claims cover all such alternative aspects that fall within the true spirit and scope of the present invention.

Claims

1. A membrane electrode assembly; A first plate separator and a second plate separator on opposite sides sandwiching the membrane electrode assembly, the first plate separator and the second plate separator having outer ends at positions away from the membrane electrode assembly; A first gas diffusion layer between the first plate separator and the membrane electrode assembly; A second gas diffusion layer between the second plate separator and the membrane electrode assembly; A sub-gasket extending laterally from the membrane electrode assembly toward at least one of the outer ends; A first seal positioned between the first plate separator and the sub-gasket; A conductive trace attached to the sub-gasket and extending on the sub-gasket from the outside of the first seal to the inside of the first seal; A fuel cell system comprising the above.

2. The sub-gasket includes a first upper side adjacent to the first seal and the first gas diffusion layer, and a second lower side adjacent to the second gas diffusion layer. The conductive trace is located on the first upper side, and a second conductive trace is located on the second lower side. The system according to Claim 1.

3. The second trace extends through the sub-gasket to the first side, enabling an electrical connection between the first trace, the second trace, and a sensor or a control device. The system according to Claim 2.

4. The sub-gasket and the trace extend outwardly beyond at least one of the outer ends. The system according to Claim 1.

5. The trace extends from the first gas diffusion layer between the first seal and the sub-gasket toward the outer end. The system according to Claim 1.

6. The conductive trace includes a first straight portion extending from the outside of the first seal toward the membrane electrode assembly, and the conductive trace further includes an upward extension portion extending toward the first plate separator. The system according to Claim 1.

7. The sub-gasket includes a tab extending beyond at least one of the outer ends in a direction away from the membrane electrode assembly, the conductive trace extends beyond at least one of the outer ends on the sub-gasket, and the tab has a longitudinal axis in a direction away from at least one of the outer ends. The system according to claim 1.

8. The system according to claim 7, wherein the sub-gasket further includes a second trace on the same side of the sub-gasket as the conductive trace.

9. The system according to claim 7, further comprising a second sub-gasket connected to a second membrane electrode assembly, wherein the sub-gasket and the second sub-gasket are vertically spaced along a vertical axis connecting the first plate separator and the second plate separator, the second sub-gasket includes a second tab, the second tab is laterally positioned relative to the first tab, and the first tab and the second tab are vertically offset from each other and aligned in a non-vertical direction.

10. The system according to claim 1, wherein the conductive trace is a metal trace printed on the sub-gasket.

11. The system according to claim 1, wherein the membrane electrode assembly, the first gas diffusion layer, and the second gas diffusion layer are adhered to the sub-gasket.

12. The system according to claim 8, wherein the conductive trace and the second trace form a thermocouple junction.

13. A method used in the manufacture of a fuel cell system, comprising: attaching a conductive trace to a sub-gasket; positioning a membrane electrode assembly on the sub-gasket such that a lateral portion of the sub-gasket extends away from the membrane electrode assembly and towards the outside of the fuel cell sub-assembly; positioning a first gas diffusion layer on a first side of the membrane electrode assembly and a second gas diffusion layer on a second side of the membrane electrode assembly; the conductive trace extending from the inside of the fuel cell assembly past the seal and towards the outside of the fuel cell assembly between the seal and the sub-gasket A method including.

14. Positioning a first plate separator on top of a first gas diffusion layer, and further including the seal contacting the first plate separator and the sub gasket, the method according to claim 13.

15. Positioning a first plate separator and a second plate separator on opposite sides sandwiching a membrane electrode assembly, the first plate separator and the second plate separator having outer ends at positions away from the membrane electrode assembly, and the conductive trace extending at least past one of the inner and outer ends, the method according to claim 13.

16. The step of attaching a conductive trace to a sub gasket includes depositing a conductive material on the sub gasket to form the trace, the method according to claim 13.

17. The step of attaching a conductive trace to a sub gasket includes attaching a conductive trace to a first side of the sub gasket, and further includes attaching a second trace to a second opposite side of the sub gasket and through the sub gasket to the first side, the method according to claim 13.

18. The sub gasket includes a tab extending outward from the inside, and the longitudinal axis of the tab extends away from the inside, and the conductive trace extends longitudinally away from the inside on the tab, the method according to claim 13.

19. Positioning a second sub gasket connected to a second membrane electrode assembly within a fuel cell subassembly such that the second sub gasket is vertically spaced along the vertical axis of the subassembly and the second tab of the second one is positioned laterally relative to the first tab, such that the first tab and the second tab are vertically offset from each other and aligned in a non-vertical direction, the method according to claim 13.

20. Positioning a second conductive trace on the same side as the conductive trace of the sub gasket, and the second conductive trace extending from the inside to the outside past the seal, the method according to claim 13.

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