Laminated fuel cell assembly

Abstract

The disclosure, in some aspects, relates to a method and apparatus for assembling a laminated fuel cell, in which an assembly head comprising one or more punches is used for dividing portions from sheet material and for transferring the portions to an electrode plate for lamination. Embodiments disclosed include a method of assembling a laminated fuel cell, the method comprising the steps of: providing a first sheet material (202b) to a first die (205); translating an assembly head (204) to a first location adjacent the first die, the assembly head comprising a first punch (501) having a surface (507) configured to engage with the first die; engaging the first punch with the first die to divide a portion from the first sheet material; adhering the first sheet portion to the surface of the first punch; translating the assembly head with the first sheet material portion to an assembly station (203) comprising an electrode plate (701); and applying the first sheet material portion to a surface of the electrode plate.

Claims

1. A method of assembling a laminated fuel cell, the method comprising the steps of: providing a first sheet material to a first die; translating an assembly head to a first location adjacent the first die, the assembly head comprising a first punch having a surface configured to engage with the first die; engaging the first punch with the first die to divide a portion from the first sheet material; adhering the first sheet portion to the surface of the first punch; translating the assembly head with the first sheet material portion to an assembly station comprising an electrode plate; and applying the first sheet material portion to a surface of the electrode plate; wherein the assembly head further comprises a second punch having a surface configured to engage a second die, the method further comprising: providing a second sheet material to the second die; translating the assembly head to a second location adjacent the second die; engaging the second punch with the second die to divide a portion from the second sheet material; translating the assembly head with the second sheet material portion to the assembly station; and, applying the second sheet material portion to the surface of the electrode plate; wherein an outer perimeter of the surface of the second punch lies entirely within an inner perimeter of the surface of the first punch.

2. A method of assembling a laminated fuel cell, the method comprising the steps of: providing a first sheet material to a first die; translating an assembly head to a first location adjacent the first die, the assembly head comprising a first punch having a surface configured to engage with the first die; engaging the first punch with the first die to divide a portion from the first sheet material; adhering the first sheet portion to the surface of the first punch; translating the assembly head with the first sheet material portion to an assembly station comprising an electrode plate; and applying the first sheet material portion to a surface of the electrode plate; wherein the assembly head further comprises a second punch having a surface configured to engage a second die, the method further comprising: providing a second sheet material to the second die; translating the assembly head to a second location adjacent the second die; engaging the second punch with the second die to divide a portion from the second sheet material; translating the assembly head with the second sheet material portion to the assembly station; and, applying the second sheet material portion to the surface of the electrode plate; wherein an outer perimeter of the surface of the second punch lies entirely within an inner perimeter of the surface of the first punch; wherein the first sheet material comprises an adhesive gasket material and the second sheet material comprises a porous gas diffusion layer material.

3. A method of assembling a laminated fuel cell, the method comprising the steps of: providing a first sheet material to a first die; translating a first assembly head to a first location adjacent the first die, the first assembly head comprising a first punch having a surface configured to engage with the first die; engaging the first punch with the first die to divide a portion from the first sheet material; adhering the first sheet portion to the surface of the first punch; translating the first assembly head with the first sheet material portion to an assembly station comprising an electrode plate; and applying the first sheet material portion to a surface of the electrode plate; wherein the first assembly head further comprises a second punch having a surface configured to engage a second die, the method further comprising: providing a second sheet material to the second die; translating the first assembly head to a second location adjacent the second die; engaging the second punch with the second die to divide a portion from the second sheet material; translating the assembly head with the second sheet material portion to the assembly station; and, applying the second sheet material portion to the surface of the electrode plate; providing a third sheet material to a third die; translating a second assembly head to a third location adjacent a third die, the second assembly head comprising a first punch having a surface configured to engage with the third die; engaging the first punch of the second assembly head with the third die to divide a portion from the third sheet material; adhering the third sheet portion to the surface of the first punch of the second assembly head; translating the second assembly head with the third sheet material portion to the assembly station; and, applying the third sheet material portion over the first and second sheet material portions.

4. The method of claim 3 wherein the third sheet portion is adhered to the surface of the first punch of the second assembly head by a vacuum applied to openings in the surface of the first punch of the second assembly head.

5. The method of claim 3 wherein the second assembly head comprises a second punch having a surface configured to engage a fourth die, the method comprising: providing a fourth sheet material to the fourth die; translating the second assembly head to a fourth location adjacent the fourth die; engaging the second punch of the second assembly head with the fourth die to divide a portion from the fourth sheet material; translating the second assembly head with the fourth sheet material portion to the assembly station; and, applying the fourth sheet material portion over the first and second sheet material portions.

6. The method of claim 5 wherein the fourth sheet portion is adhered to the surface of the second punch of the second assembly head by a vacuum applied to openings in the surface of the second punch of the second assembly head.

7. The method of claim 5 wherein the second assembly head is translated from the fourth location to the assembly station with both the third and fourth sheet material portions adhered to respective surfaces of the first and second punches of the second assembly head, and wherein the third and fourth sheet material portions are applied over the first and second sheet material portions in a single operation.

8. The method of claim 5, wherein the first assembly head further comprises a third punch configured to engage a fifth die at a fifth location, the method further comprising: providing a fifth sheet material to the fifth die; translating the first assembly head to the fifth location; engaging the third punch with the fifth die to divide a portion from the fifth sheet material; translating the first assembly head with the fifth sheet material portion to the assembly station; and, applying the fifth sheet material portion over the first and second sheet material portions.

9. The method of claim 8 wherein the fifth sheet material portion forms a membrane electrode assembly for the fuel cell assembly.

Description

DRAWINGS

(1) Aspects and embodiments of the disclosure are described in further detail below by way of examples and with reference to the enclosed drawings in which:

(2) FIG. 1 is a schematic exploded cross-section of a polymer electrolyte membrane fuel cell.

(3) FIG. 2 is a perspective view of an exemplary apparatus for assembling a laminated fuel cell.

(4) FIG. 3 is a plan view of the apparatus of FIG. 2.

(5) FIG. 4 is a side elevation view of the apparatus of FIGS. 2 and 3.

(6) FIGS. 5 and 6 comprise a series of cut-away perspective views of an exemplary assembly head for the apparatus of FIGS. 2-4.

(7) FIG. 7 comprises a series of schematic diagrams illustrating a series of processing steps in assembling a laminated fuel cell assembly.

(8) The conventional fuel cell configuration shown in FIG. 1 has been described above as part of the background art.

(9) A perspective view of an exemplary apparatus 200 is illustrated in FIG. 2. The apparatus 200 is also shown in plan view in FIG. 3 and in side elevation view in FIG. 4. A number of sheet feeding lines 201a-g are provided to feed a corresponding number of sheet materials 202a-g. In the embodiment shown, a total of seven feed lines are provided, configured to feed a linked series of MEAs 202a, two adhesive gasket sheet materials 202b, 202f, two gas diffusion layer materials 202c, 202e, a series of linked anode electrode plates 202d and a series of linked cathode electrode plates 202g. The materials for the gasket and gas diffusion layer lines 201b, 201c, 201e, 201f are provided in raw form, i.e. with only a defined sheet thickness and width, whereas the materials for the anode and cathode electrode plates 202d, 202g are provided in a pre-prepared form with surface features such as fluid flow channels already in place, which may for example have been formed by stamping and/or etching. To allow the anode and cathode plates to be indexed through the assembly 200, successive plates are connected to each other, although these plates may alternatively be fed from a hopper comprising stacks of such parts. The gasket and gas diffusion materials may be supplied from reel or sheet fed stock. The gasket material may be supplied in the form of an adhesive sheet with a backing paper on one or both sides, while the gas diffusion layer material may be applied without any adhesive layer.

(10) The MEA line 201a is provided with ready-made membrane-electrode assemblies, which in the embodiment shown are linked together for indexing and require only a final cut to trim and divide the individual MEA components before assembly. The MEAs can also be provided either as a reel fed sheet or as individual parts from a sheet feeder. For each feed line, it is advantageous for the assembly 200 to be provided with material in the form of a sheet or a series of linked components, because this reduces the complexity of the assembly.

(11) The anode plates 202d are indexed by the feed line 201d towards a first intermediate laminating, or assembly, station 203, where the gasket, gas diffusion layer and membrane electrode assembly components are laminated to each anode plate. For this purpose, a multi-functional assembly head 204 is provided. The assembly head 204 is traversable across the feed lines along one or more axes by means of a pick-and-place mechanism (not shown, for clarity). In some exemplars, the assembly head 204 is translatable along the x-axis (shown in FIG. 2), which is in a direction along the plane of the feed lines and transverse to the direction the feed lines are configured to provide the sheet materials, and can be raised and lowered in the z-axis, i.e. in a direction orthogonal to the plane of the feed lines.

(12) An exemplary series of operations leading to assembly comprising an anode plate with a gas diffusion layer and an adhesive gasket proceeds as follows.

(13) An anode plate is first advanced to the assembly station 203. The anode plate may be accurately located at the assembly station 203 by being located with one or more pins in the assembly station engaging with corresponding holes in the anode plate. The assembly head 204 translates to a first die 205 at a location on the gasket feed line 201b. A punch in the assembly head then engages with the die across the gasket material 202b, cutting out a gasket-shaped piece from the sheet. The punch is provided with a series of openings through which a vacuum is applied, so that the gasket is held on to the assembly head 204. The assembly head then retracts from the die 205 and translates to a second die 206, over which the gas diffusion layer material is provided.

(14) With the gasket material still in place on the assembly head, a second punch in the assembly head is engaged with the second die across the gas diffusion layer material, cutting out a portion of the material that is surrounded by the existing gasket material. The assembly head 204 then retracts from the second die 206 and translates across to the assembly station 203, carrying both the gasket and gas diffusion layer portions. In a single operation, the assembly head then applies the gasket and gas diffusion layers to the anode plate in position at the assembly station 203. Because the gas diffusion layer fits entirely within the gasket layer, the gas diffusion layer is held laterally in place once it has been applied to the anode plate. No adhesive is therefore required on the gas diffusion layer, although at least a partial adhesive layer may be provided to ensure that the layer does not shift during subsequent steps.

(15) Once the gasket and gas diffusion layer have been applied, an MEA layer is applied over the anode plate. This may be done by translating the assembly head 204, which may comprise a third punch for cutting out and holding on to an MEA component, or alternatively may be carried out by using a second assembly head 207 specifically for the purpose of cutting and translating the MEA components to the assembly station 203.

(16) In the first alternative mentioned above, a second assembly head 208, nominally identical to the first assembly head 204, may be provided to obtain gasket and gas diffusion layer portions from respective dies 209, 210, fed by sheet feed lines 201g, 201f. This second assembly head 208 can therefore be used to speed up the overall process by carrying out other operations in parallel while the first assembly head is retrieving the MEA from the MEA station 211.

(17) In the second alternative, the first assembly head 204 may be used to obtain gasket and gas diffusion layer portions from dies 209, 210 while the second assembly head 207 is used to obtain the MEA. In this alternative, the MEA station 211 is preferably offset from the assembly station 203, so that any conflict between movement of the second assembly head 207 and the first assembly head 204 is avoided. The second assembly head 207 is configured to translate between the MEA assembly station 211 and the first assembly station 203 for transferring an MEA component to the anode plate.

(18) In each of the first and second alternatives, some operations are carried out in parallel, and the overall assembly process can therefore be quicker than with the use of only one assembly head. The use of a separate assembly head specifically for the transfer of the MEA layer also reduces the complexity of design of the assembly head 204, as this is only required to carry out two cutting processes rather than three.

(19) Once the anode plate has been provided with the required gaskets, gas diffusion layers and MEA, the anode plate feed line 201d is indexed to move the anode plate to a second assembly station 212. A third assembly head 213, in position over a cathode plate fed by the cathode plate feed line 201g, then lifts a cathode plate from the cathode sheet material 202g and translates the cathode plate over to the second assembly station 212. A cropping blade actuator 214 is operated to divide the cathode plate from the sheet-fed line.

(20) Once the cathode plate is applied at the second assembly station 212, the anode feed line indexes the finished fuel cell assembly to a third assembly station 217 and a further cropping blade actuator 215 is operated twice in successive indexing steps, to divide the assembled fuel cell from the anode feed line 202d. The assembled fuel cell is then passed to an assembly chute 216 for further assembly. The third assembly station 217 is preferably provided with a vacuum bed for holding the fuel cell assembly in position during the cropping operations.

(21) For each of the assembly heads described above, a vacuum system is preferably used to retain components between a punching step and a lamination step at the assembly stations 203, 212. Further details of the assembly head 204 are described below.

(22) Also shown in FIG. 1 are various waste chutes 218-223, along which scrap material from feed lines 201a-c,e-g is fed after cutting operations to divide the various components from the sheet fed lines.

(23) One or more cameras 401 (FIG. 4) may be provided below the sheet feeding assembly 201 to allow for the relative position of the components to be monitored during assembly. The camera 401 may for example be used to ensure that edges of the gasket and gas diffusion layer materials are in a correct position over the respective dies. A camera may also be used to monitor and, if necessary, adjust the position of the anode or cathode lines.

(24) FIGS. 5 and 6 show different perspective cut-away views of an exemplary assembly head 204 in different configurations for cutting and translating gasket and gas diffusion layer sheet materials. In parts A and B of FIGS. 5a and 6a, the assembly head is in a configuration adjacent a gasket die 205, with a first punch comprising an outer edge 502, an inner edge 503 and further features 504 configured to provide fluid flow channels in the gasket material on engagement with the gasket die 205. When the first punch contacts the die 205, outer and inner profiles of a gasket are simultaneously formed by the inner edge 503, outer edge 502 and further features 504, which results in waste material that is ejected. A vacuum holder 501 is provided between the inner and outer edges 504, 502 in order to retain the gasket on a surface 507 of the punch after this punching operation. After engagement with the gasket die 205, the first punch is retracted and a second punch 505, comprising an outer edge 503 common with the inner edge of the first punch 501, is extended and is engaged with the gas diffusion layer die 206 (part C). After both sheet materials have been divided, the surfaces 507, 508 of the respective first and second punches 501, 505 are aligned with each other and the sheet materials (not shown) that are held in place on the surfaces 507, 508 are applied to the anode plate at the assembly station 203 (FIG. 2), as shown in part D of FIGS. 5 and 6.

(25) FIGS. 5 and 6 also illustrate vacuum lines 509, 510 provided on the assembly head 204, which provide suction to openings provided on the surfaces 507, 508 of the first and second punches 501, 505 for keeping the sheet materials in place during translation to the assembly station 203. A first vacuum line 509 provides suction for the surface 507 of the first punch 501, while a second vacuum line 510 provides suction for the surface 508 of the second punch 505.

(26) FIG. 7 illustrates schematically a series of steps in an exemplary process for transferring a gasket and a gas diffusion layer from respective dies 205, 206 to an assembly station 203 on which is provided an anode plate 701. In step A, the assembly head is in position over the gasket die. A gasket material is provided over the die, and the assembly head engages the first punch 501 (FIGS. 5, 6) with the gasket die 205 (step B). A portion 702 of the gasket material is ejected through the gasket die 205 in the process, and is discarded. The assembly head 204 then retracts from the gasket die 205 (step C), and translates over to the gas diffusion layer die 206 (step D). The assembly head 204 then engages the second punch with the gas diffusion layer die 206 (step E), and retracts from the gas diffusion layer die 206, with both the gasket and gas diffusion layer portions attached to the respective surfaces of the first and second punches. The assembly head 204 then translates over to the assembly station 203 (step G), and applies the gasket and gas diffusion layer portions to the anode plate 701 (step H). The assembly head 204 then retracts from the assembly station (step I), taking a backing paper away from the upper surface of the gasket material. The backing paper is then discarded by translating to the assembly head 204 to a waste material chute or hopper and releasing the vacuum applied to the surface of the first punch, and optionally applying a positive pressure to ensure the backing paper is cleared and any residual material is ejected.

(27) In subsequent processing steps, the MEA is applied over the anode plate 701. A further gasket and gas diffusion layer is then applied, following the steps as shown in FIG. 7. A cathode plate is then applied to complete the fuel cell assembly.

(28) The assembly head 204 is preferably configured such that the above operations can be carried out using a pick and place arm able to move the head along at least two linear axes. The head may be further configured to include an additional rotation axis so that additional processes could be accommodated.

(29) In the exemplars described above, separate feed lines 201b, 201f are provided for the two gasket materials 202b, 202f, to accommodate different shapes and configurations of gaskets on the anode and cathode sides. Similarly, separate feed lines 201c, 201e are provided for the two gas diffusion layer materials 202c, 202e so that different shapes and materials can be used for the anode and cathode sides. These lines could be simplified by consolidating the gasket lines into one common line and/or the gas diffusion lines into one common line, which would further simplify the process and the associated inventory requirements.

(30) While the method and apparatus have been described in terms of what are presently considered to be the most practical and preferred implementation, exemplars and/or embodiments, it is to be understood that the disclosure need not be limited to the disclosed implementation, exemplars and/or embodiments. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.

(31) It should also be understood that a variety of changes may be made without departing from the essence of the invention. Such changes are also implicitly included in the description. They still fall within the scope of this disclosure. It should be understood that this disclosure is intended to yield a patent covering numerous aspects both independently and as an overall system and in both method and apparatus modes.

(32) Further, each of the various elements of the disclosure, exemplars, aspects thereof and claims may also be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of any apparatus, a method or process, or even merely a variation of any element of these.

(33) Particularly, it should be understood that as the disclosure relates to elements claimed, the words for each element may be expressed by equivalent apparatus terms or method terms—even if only the function or result is the same.

(34) Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled.

(35) It should be understood that all actions may be expressed as a means for taking that action or as an element which causes that action.

(36) Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates.

(37) Any patents, publications, or other references mentioned in this application for patent are hereby incorporated by reference. In addition, as to each term used it should be understood that unless its utilization in this application is inconsistent with such interpretation, common dictionary definitions should be understood as incorporated for each term and all definitions, alternative terms, and synonyms such as contained in at least one of a standard technical dictionary recognized by artisans and the Random House Webster's Unabridged Dictionary, latest edition are hereby incorporated by reference.

(38) Finally, all referenced listed in the Information Disclosure Statement or other information statement filed with the application or thereafter are hereby appended and hereby incorporated by reference; however, as to each of the above, to the extent that such information or statements incorporated by reference might be considered inconsistent with the patenting of claimed invention(s), such statements are expressly not to be considered as made by the applicant(s).

(39) In this regard it should be understood that for practical reasons and so as to avoid adding potentially hundreds of claims, the applicant has presented claims with initial dependencies only.

(40) Support should be understood to exist to the degree required under new matter laws—including but not limited to United States Patent Law 35 USC 132 or other such laws—to permit the addition of any of the various dependencies or other elements presented under one independent claim or concept as dependencies or elements under any other independent claim or concept.

(41) To the extent that insubstantial substitutes are made, to the extent that the applicant did not in fact draft any claim so as to literally encompass any particular embodiment, and to the extent otherwise applicable, the applicant should not be understood to have in any way intended to or actually relinquished such coverage as the applicant simply may not have been able to anticipate all eventualities; one skilled in the art, should not be reasonably expected to have drafted a claim that would have literally encompassed such alternative embodiments.

(42) Further, the use of the transitional phrase “comprising” is used to maintain the “open-end” claims herein, according to traditional claim interpretation. Thus, unless the context requires otherwise, it should be understood that the term “compromise” or variations such as “comprises” or “comprising”, are intended to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps.

(43) Such terms should be interpreted in their most expansive forms so as to afford the applicant the broadest coverage legally permissible.

(44) The Abstract is provided to comply with 37 CFR §1.72(b) to allow the reader to quickly ascertain the nature and gist of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.