Fuel cell manufacturing method

Abstract

To provide a technique that can effectively suppress warping of cells during the manufacture of fuel batteries.SOLUTION: A fuel battery manufacturing method includes the steps of: preparing a cell precursor including a membrane-electrode-gas diffusion layer assembly of a fuel battery, a pair of separators arranged so as to sandwich the assembly, and a thermoplastic resin; heating the thermoplastic resin using a first heating mold and a second heating mold arranged opposite each other and capable of heating the cell precursor; and cooling the thermoplastic resin using a first cooling mold and a second cooling mold arranged opposite each other and capable of cooling the cell precursor. In this manufacturing method, a temperature difference is generated in at least a part of the contact surfaces where the first heating mold and the second heating mold contact the cell precursor and / or at least a part of the contact surfaces where the first cooling mold and the second cooling mold contact the cell precursor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in this specification relates to a method for manufacturing a fuel cell.

[0002] For example, a fuel cell includes cells each composed of an electrode composite and a pair of separators as constituent units. The cells are integrated by heating and then cooling the thermoplastic resin of a cell precursor in which the electrode composite is interposed with a thermoplastic resin between it and the separator. Patent Document 1 describes a method of performing two cooling steps to suppress warping of the cells. In this method, the latter cooling step is performed at a lower temperature than the former cooling step.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The surface of the separator of the cell has a complex uneven shape for the flow path of the gas cooling water. Therefore, the upper and lower press molds for cooling have different shapes of the upper and lower press surfaces, and the areas and regions for pressing the cell precursor do not match between the upper and lower molds. Also, even in one-sided molds, the press surfaces are not formed symmetrically left and right. For this reason, even when pressing the cell precursor at the same temperature using the upper and lower press molds in the heating process and the cooling process, the heating effect and the cooling effect become non-uniform within the upper and lower press surfaces and within one-sided press surfaces. For this reason, warping and undulation of the cells have not been sufficiently suppressed.

[0005] This specification provides a technology that can effectively suppress warping of cells during the manufacture of fuel cells.

Means for Solving the Problems

[0006] The technology disclosed herein is embodied in a method for manufacturing a fuel cell. The method comprises: preparing a cell precursor comprising a membrane-electrode-gas diffusion layer assembly of a fuel cell, a pair of separators arranged to sandwich the assembly, and a thermoplastic resin; a heating step of heating the thermoplastic resin using a first heating type and a second heating type arranged opposite each other and capable of heating the cell precursor; and a cooling step of cooling the thermoplastic resin using a first cooling type and a second cooling type arranged opposite each other and capable of cooling the cell precursor. In this manufacturing method, a temperature difference is generated in at least a portion of the contact surfaces in which the first heating type and the second heating type contact the cell precursor, and / or in at least a portion of the contact surfaces in which the first cooling type and the second cooling type contact the cell precursor.

[0007] According to the present inventors, it has been found that when a cell precursor is heated and / or cooled in a mold arranged opposite each other, there is a suitable temperature difference for suppressing warping.

[0008] According to this manufacturing method, the first and second heating molds used in the heating process and the first and second cooling molds used in the cooling process generate a temperature difference at least in part of the contact surface that comes into contact with the cell precursor. Therefore, by heating and / or cooling these contact surfaces to the same temperature, warping that occurs when heating and cooling the thermoplastic resin can be suppressed or avoided.

[0009] Furthermore, this manufacturing method allows for the imparting of sufficient heating and cooling effects to the cell precursor, making it possible to shorten the heating and cooling steps or reduce the number of heating and cooling steps.

[0010] The technology disclosed herein is embodied in a manufacturing apparatus for fuel cell cells. The manufacturing apparatus comprises a first heating type and a second heating type, which are arranged opposite each other, for heating the thermoplastic resin of a cell precursor comprising a membrane-electrode-gas diffusion layer assembly of the fuel cell, a pair of separators arranged to sandwich the assembly, and a thermoplastic resin interposed between the assembly and the separators; a first cooling type and a second cooling type, which are arranged opposite each other, for cooling the thermoplastic resin of the cell precursor; and a temperature control device that generates a temperature difference in at least a portion of the contact surfaces in which the first heating type and the second heating type contact the cell precursor, and / or in at least a portion of the contact surfaces in which the first cooling type and the second cooling type contact the cell precursor.

[0011] According to this manufacturing apparatus, a temperature difference is generated in at least a portion of the contact surfaces in which the first heating mold and the second heating mold contact the cell precursor, and / or in at least a portion of the contact surfaces in which the first cooling mold and the second cooling mold contact the cell precursor. By heating and / or cooling these contact surfaces to the same temperature, warping that occurs when heating and cooling the thermoplastic resin can be suppressed or avoided. [Brief explanation of the drawing]

[0012] [Figure 1] This diagram shows a schematic example of the manufacturing process for a fuel cell. [Figure 2] This is a plan view of a fuel cell. [Figure 3] This is a cross-sectional view showing the relationship between the upper and lower molds of a cooling press mold and the cell precursor. [Figure 4] This diagram combines a plan view of the cell with a diagram showing the relationship between the temperature difference ΔT between the upper and lower molds and the warping force of the cell near the flow path. [Figure 5] This is a cross-sectional view showing the relationship between the upper and lower molds of a cooling press mold and the cell precursor. [Figure 6] This figure shows an additional cooling region in the cell precursor. [Modes for carrying out the invention]

[0013] One aspect of a fuel cell manufacturing method disclosed herein (hereinafter also simply referred to as the manufacturing method) comprises the steps of: preparing a cell precursor comprising a membrane-electrode-gas diffusion layer assembly of a fuel cell, a pair of separators arranged to sandwich the assembly, and a thermoplastic resin; a heating step of heating the thermoplastic resin using a first heating type and a second heating type arranged opposite each other and capable of heating the cell precursor; and a cooling step of cooling the thermoplastic resin using a first cooling type and a second cooling type arranged opposite each other and capable of cooling the cell precursor. The manufacturing method includes generating a temperature difference in at least a portion of the contact surfaces in which the first heating type and the second heating type contact the cell precursor, and / or at least a portion of the contact surfaces in which the first cooling type and the second cooling type contact the cell precursor.

[0014] Another embodiment of the manufacturing method includes a cooling step in which the first cooling mold has a first cooling surface that can contact and cool the first surface of the cell precursor, and the second cooling mold has a second cooling surface that can contact and cool the second surface of the cell precursor, and the cooling step may include generating a temperature difference in at least a portion of the first cooling surface and the second cooling surface. According to this embodiment, by generating a temperature difference in at least a portion of the first cooling surface and the second cooling surface, warping can be suppressed or avoided more effectively and reliably.

[0015] Another embodiment of the manufacturing method includes, when the contact area of ​​the first portion of the first cooling surface with the cell precursor is smaller than the contact area of ​​the second portion of the second cooling surface facing the first portion with the cell precursor, cooling the temperature of at least the first portion to a lower temperature than the second portion, and when the contact area of ​​the second portion is smaller than the contact area of ​​the first portion, cooling the temperature of at least the second portion to a lower temperature than the first portion. According to this manufacturing method, differences in cooling effect due to differences in the contact area between the first portion and the second portion can be suppressed or avoided, thereby cooling the thermoplastic resin while suppressing warping.

[0016] Another aspect of the manufacturing method includes a cooling step using one or both of the first cooling mold having the first cooling surface including a surface for cooling a region where the thermoplastic resin is interposed and a surface for cooling a region where the thermoplastic resin is not interposed, and the second cooling mold having the second cooling surface including a surface for cooling a region where the thermoplastic resin is interposed and a surface for cooling a region where the thermoplastic resin is not interposed. According to this manufacturing method, since the first cooling mold and the second cooling mold have a surface for cooling a region where the thermoplastic resin is not interposed in addition to the surface for cooling a region where the thermoplastic resin is interposed, the difference in the cooling effect on the cell precursor of the surface for cooling the region where the thermoplastic resin is interposed can be suppressed or avoided, and the thermoplastic resin can be cooled while suppressing warping.

[0017] All of the above various other aspects of the manufacturing method of the fuel cell are applied to the first heating mold, the second heating mold, the first cooling mold, the second cooling mold, and the temperature control device in the manufacturing apparatus of the fuel cell.

[0018] <First Embodiment> Hereinafter, embodiments of a method for manufacturing a fuel cell according to the present disclosure, more specifically, a method for manufacturing a cell of a fuel cell, etc. will be described with reference to the drawings. Hereinafter, first, a general configuration of a fuel cell will be described, and then a method for manufacturing the cell and a manufacturing apparatus for the fuel cell will be described. FIG. 1 shows an example of a manufacturing process of the cell, FIG. 2 shows a plan view of the cell, FIG. 3 shows the relationship between the upper and lower molds of the cooling press mold and the cell precursor in the cooling process of the cell, and FIG. 4 shows the relationship between the temperature difference and the warping force in a pair of molds.

[0019] (Fuel Cell) Although not shown, a fuel cell generally includes a stack configured by providing a current collector, an end plate, etc. in a laminate in which a plurality of cells are stacked, a hydrogen gas circulation mechanism as a fuel gas, an air circulation mechanism as an oxidant gas, and a cooling mechanism for the fuel cell.

[0020] Fig. 2 shows a plan view of a fuel cell 10. The cell 10 includes a membrane - electrode - gas diffusion layer assembly (MEGA) 12, a resin frame 14 surrounding the MEGA 12, and a pair of separators 16 and 18 sandwiching them.

[0021] Although not shown, the MEGA 12 includes a membrane - electrode assembly and gas diffusion layers laminated on both sides of the membrane - electrode assembly, and is disposed in a rectangular opening of the resin frame 14. The membrane - electrode assembly is configured such that an anode and a cathode are respectively disposed on both sides of the membrane, and a fuel gas and an oxidant gas for power generation are supplied thereto.

[0022] The resin frame 14 is formed, for example, in a rectangular frame shape surrounding the MEGA 12. The resin frame 14 has a plurality of manifold holes H1 - H6 forming manifolds M1 - M6 at the outer edge portion. The resin frame 14 melts or softens by heating and joins with the separators 16 and 18. At least the surface layer of the resin frame 14 facing the separators 16 and 18 is, for example, a thermoplastic resin having a softening point of about 160°C.

[0023] The separators 16 and 18 are made of a material having gas barrier properties and conductivity, such as a carbon - made member like dense carbon obtained by compressing carbon particles to make it gas - impermeable, or a metal member such as press - formed stainless steel or titanium. One of the separators 16 and 18 is the anode - side separator 16 disposed on the A - surface, and the other is the cathode - side separator 18 disposed on the B - surface. The A - surface is an example of the first surface of the cell precursor in this specification.

[0024] The anode-side separator 16 is provided with a plurality of striated refrigerant flow channels 20 that distribute refrigerant to surface A, which is the surface opposite to MEGA 12. The separator 16 is also provided with a plurality of striated flow channel grooves for distributing fuel gas on the surface facing MEGA 12 (not shown). The cathode-side separator 18 is provided with a plurality of striated flow channel grooves for distributing oxidizer gas on the surface facing MEGA 12, and a plurality of striated refrigerant flow channels for distributing refrigerant to surface B, which is the surface opposite to MEGA 12. Surface B is an example of the second surface of the cell precursor in this specification.

[0025] Separators 16 and 18 have multiple manifold holes H1 to H6 that constitute manifolds M1 to M6. Manifold holes H1 and H2 constitute part of the fuel gas passage, manifold holes H3 and H4 constitute part of the oxidizer gas passage, and manifold holes H5 and H6 constitute part of the refrigerant passage.

[0026] Manifold holes H1 and H2 are provided to discharge fuel gas supplied from manifold M1 to manifold M2 via the fuel gas passage. Manifold holes H3 and H4 are provided to discharge oxidizer gas supplied from manifold M3 to manifold M4 via the oxidizer gas passage. Manifold holes H5 and H6 are provided to discharge refrigerant supplied from manifold M5 to manifold M6 via the refrigerant passage 20, etc.

[0027] Within cell 10, the fuel gas passage, oxidizer gas passage, and manifold holes H1 to H6 are separated by a resin frame 14 and a separately provided gasket.

[0028] (Method of manufacturing fuel cells) Next, a method for manufacturing a fuel cell according to this disclosure will be described with reference to Figures 1, 3, and 4.

[0029] The manufacturing method of this embodiment includes at least a manufacturing step for the cell 10. A fuel cell stack is constructed by stacking multiple cells 10 and installing current collectors, etc. A fuel cell system is constructed by further connecting a fuel gas flow mechanism, an oxidant gas flow mechanism, and a refrigerant flow mechanism to this fuel cell stack. The stacking of the cells 10, the installation of current collectors, etc., and the connection of the fuel gas flow mechanism, etc. can be carried out by methods well known to those skilled in the art.

[0030] This manufacturing method comprises a preparation step S1 for the cell precursor 30, a heating and pressing step S2 for the cell precursor 30, and a cooling and pressing step S3 for the cell precursor 30.

[0031] In preparation step S1, a cell precursor 30 is prepared in which the MEGA 12, held by the resin frame 14, is sandwiched between a pair of separators 16 and 18. The cell precursor 30 is a state in which the MEGA 12, the resin frame 14, and the pair of separators 16 and 18 are joined together as a single unit, and the same reference numeral is used for common components.

[0032] Next, in the heating and pressing step S2, the cell precursor 30 is heated under pressure at a temperature exceeding the softening point of the resin frame 14.

[0033] Although not shown in the diagram, in the heating press step S2, the cell precursor 30 is heated by a pair of upper and lower molds positioned opposite each other above and below the heating press mold. More specifically, the cell precursor 30 is placed on the lower mold, and the upper mold is lowered to heat and pressurize the resin frame 14 between the upper and lower molds, which are heated to a predetermined temperature, via the separators 16 and 18. As a result, the thermoplastic resin of the resin frame 14 softens, and the separators 16 and 18, MEGA 41, and resin frame 14 come into close contact. The upper and lower molds of the heating press mold are examples of the first and second heating molds disclosed herein.

[0034] Next, the cooling press process S3 is performed. As shown in Figure 3, in the cooling press process S3, the A and B sides of the cell precursor 30 are cooled at a temperature below the softening point of the resin frame 14, and at different temperatures. The following describes a method of cooling the cell precursor 30 using a cooling press mold 40 while applying pressure to the A and B sides of the cell precursor 30 at different temperatures.

[0035] Figure 3 shows the state when attempting to cool the cell precursor 30 corresponding to cell 10 using the cooling press die 40. Figure 3 shows the relationship between the cell precursor 30 corresponding to line III-III of cell 10 shown in Figure 2 and the cooling press die 40. The cooling press die 40 comprises an upper die 42 and a lower die 44 arranged opposite each other vertically. The upper die 42 and lower die 44 of the cooling press die 40 are examples of the first and second cooling types disclosed herein.

[0036] The upper mold 42 has a cooling surface 42a for cooling the portion of the cell precursor 30 on surface A that is to be sealed by the resin frame 14. The cooling surface 42a has cooling portions 42b in the portions corresponding to the C and D edges of the outer peripheral edge surrounding the power generation region of the cell precursor 30 (in Figure 3, the portion where manifold holes H1 to H6 are not formed). The cooling portions 42b are provided as convex portions that contact and pressurize the A surface of the cell precursor 30. The cooling surface 42a is an example of the first cooling surface disclosed herein, and the cooling portion 42b is an example of the first portion disclosed herein.

[0037] The lower mold 44 also has a cooling surface 44a for cooling the portion of the cell precursor 30 on its B-side that is to be sealed by the resin frame 14. The cooling surface 44a has, for example, cooling portions 44b in the portions corresponding to the C-edge and D-edge of the outer peripheral edge surrounding the power generation region of the cell precursor 30. The cooling portions 44b are provided as convex portions that are in contact with the B-side of the cell precursor 30 to cool and pressurize. The cooling surface 44a is an example of the second cooling surface disclosed herein, and the cooling portions 44b is an example of the second portion disclosed herein.

[0038] The upper die 42 and lower die 44 of the cooling press die 40 are equipped with a temperature control device (not shown) that can set the cooling surface 42a of the upper die 42 and the cooling surface 44a of the lower die 44 to different temperatures. Generally, temperature control devices such as cooling devices in cooling press dies 40 are well known. For example, a cooling structure can be described in which a refrigerant flow path is provided along the vicinity of the cooling surfaces 42a and 44a inside the upper die 42 and lower die 44. Here, by circulating refrigerants adjusted to different temperatures through the respective cooling flow paths of the upper die 42 and lower die 44, the temperatures of the respective cooling surfaces 42a and 44a can be made different.

[0039] Such a cooling press die 40 can be obtained by providing a temperature control device that has a refrigerant supply source or refrigerant supply path capable of supplying refrigerants at different temperatures to the upper die 42 and lower die 44, as well as by providing a temperature control device that adjusts the amount of refrigerant on the cooling surfaces 42a and 44a to make the temperatures of the cooling surfaces 42a and 44a different.

[0040] In the cooling press process S3, the temperatures of the cooling surface 42a of the upper die 42 and the cooling surface 44a of the lower die 44 are pre-set to temperatures below the softening temperature of the thermoplastic resin of the resin frame 14, and a cooling press mold 40 is used in which the temperature of the cooling surface 42a is cooled to a lower temperature than that of the cooling surface 44a. In other words, a cooling press mold 40 is used in which a temperature difference is pre-generated between the cooling surfaces 42a and 44a, with the temperature of the cooling surface 42a being lower.

[0041] By doing so, even though the cooling portion 42b has a smaller contact area than the cooling portion 44b, the cooling portion 42b is at a lower temperature than the cooling portion 44b. This suppresses or avoids the transmission of different cooling effects to the C and D edges of the cell precursor 30 from the top and bottom, resulting in more uniform cooling of the thermoplastic resin at the C and D edges from the top and bottom, and thus enabling the thermoplastic resin to solidify. This suppresses or avoids warping of the cell 10.

[0042] Figure 4 shows an example of evaluation results for a cooling press die 40 in which the contact area of ​​the cooling portion 42b corresponding to the C and D edges of the cell precursor 30 with respect to the cell precursor 30 is smaller than that of the cooling portion 44b. Figure 4 shows the evaluation results of the relationship between the temperature difference ΔT (cooling temperature of cooling surface 44a - cooling temperature of cooling surface 42a) between the cooling surfaces 42a and 44a of the cooling press die 40 and the warpage of the cell 10 obtained in the final result. The warpage was evaluated as the warpage force (N) detected at a part of the outer edge of each of the manifold holes H1 (a supply port for hydrogen, which is the fuel gas of the cell 10), H2 (a discharge port for hydrogen), H3 (a supply port for oxygen as an oxidizing gas), and H4 (a discharge port for oxygen) shown in Figure 2 (a warpage force that is convex in the direction of surface A is a positive warpage force). In the graph in Figure 4, the leftmost column of each region, REF, has a ΔT of zero, and ΔT1 to ΔT5 are arranged to the right such that ΔT gradually increases.

[0043] As shown in Figure 4, at each location, a tendency for the warping force to decrease was observed within a certain range of ΔT compared to when ΔT was zero.

[0044] From the above, by generating a temperature difference between the cooling surface 42a of the upper die 42 and the cooling surface 44a of the lower die 44 of the cooling press die 40, and cooling the cell precursor 30, warping caused by uneven cooling effect due to the difference in the contact area between the cooling surfaces 42a and 44a and the cell precursor 30 can be suppressed or avoided.

[0045] Furthermore, by implementing this cooling press process, it is possible to obtain cells with suppressed or avoided warping by performing only a single, short-duration cooling press process, without having to perform multiple cooling processes as in the conventional method. In other words, cells with suppressed warping can be obtained in a short time.

[0046] Furthermore, the temperature difference generated between the cooling surfaces 42a and 44a can be set appropriately by conducting evaluation experiments based on this disclosure. In addition, although the above description has focused on the size of the contact area with the cooling parts 42b and 44b, setting such a temperature difference may also be effective when there are differences in the size of the contact area across the entire cooling surfaces 42a and 44a. Moreover, regardless of the size of the contact area between the cooling surfaces 42a and 44a and the cooling parts 42b and 44b, setting a temperature difference in at least a portion of the cooling surfaces 42a and 44a may be effective from the standpoint of their shapes and other factors.

[0047] <Second Embodiment> Next, another embodiment of the fuel cell manufacturing method disclosed herein will be described with reference to Figure 4. Figure 5 shows a cross-section along line III-III in Figure 2 when attempting to cool the cell precursor 30, which corresponds to the cell 10 shown in Figure 2, in a cooling press mold 140.

[0048] This manufacturing method has the same configuration as the first embodiment, except that a cooling press step S3 is performed using a cooling press die 140 instead of the cooling press die 40 used in the first embodiment. In this embodiment, the cooling surfaces 142c and 142d of the cooling press die 140 are cooled in such a way that a temperature difference is generated. In the following description, only the cooling press step S3 using the cooling press die 140 will be described, and the other details will be omitted.

[0049] This cooling press process S3 uses a cooling press die 140. The cooling surface of the upper die 142 of the cooling press die 140 is configured to generate a temperature difference within its surface. Such a configuration of the upper die 142 includes, for example, as shown in Figure 5, a divided type in which the cooling surface that cools the cell precursor 30 while pressurizing it is divided into two or more sections, and the temperature of each divided section can be controlled individually. In addition to being a divided type, such an upper die 142 can also be obtained by using a refrigerant flow path configured to allow temperature control of the refrigerant flow path size, number of sections, arrangement, and refrigerant supply source.

[0050] As shown in Figure 5, the cooling press die 140 has an upper die 142 which is divided into an upper die 142a on the C-edge side and an upper die 142b on the D-edge side of the cell precursor 30. The upper die 142a has a cooling surface 142c for the cell precursor 30, and the upper die 142b has a cooling surface 142d for the cell precursor 30. The lower die 144 has a cooling surface 144a for the cell precursor 30. Note that at the C-edge and D-edge sides of the cell precursor 30, the contact area of ​​the cooling surface 144a with respect to the cell precursor 30 is greater than that of the cooling surfaces 142c and 142d. The upper die 142 and lower die 144 of the cooling press die 140 are examples of the first and second cooling dies disclosed herein, the cooling surfaces 142c and 142d are examples of the first cooling surface, and the cooling surface 144a is an example of the second cooling surface.

[0051] In the cooling press process S3, the cooling surfaces 142c, 142d, and 144a of the cooling press die 140 are pre-cooled to a temperature below the softening point of the resin frame 14. The cooling surfaces 142c and 144a of the cooling press die 140 are cooled to a predetermined same temperature, while the cooling surface 142d is cooled to a lower temperature than the cooling surface 142c. As a result, a temperature difference occurs between the cooling surfaces 142c and 142d. A temperature difference also occurs between the cooling surface 142d and the cooling surface 144a. Consequently, the A side of the cell precursor 30 is cooled at a lower temperature on the D edge side than on the C edge side, and the B side of the cell precursor 30 is cooled at a uniform temperature across the entire cooling surface 144a.

[0052] By using the cooling press die 140 to cool the cooling surfaces 142c, 142d, and 144a at the above-mentioned temperatures, and by cooling the A and B sides of the cell precursor 30 while applying pressure, the transmission of different cooling effects to the D edge of the cell precursor 30 is suppressed or avoided. As a result, the thermoplastic resin in the cell precursor 30 is cooled more uniformly, allowing the thermoplastic resin to solidify. This suppresses or avoids warping of the cell 10. Furthermore, a cell 10 with suppressed warping can be obtained in a short time by performing only a single cooling press process.

[0053] The mode of temperature difference generated on the cooling surfaces 142c and 142d of the upper mold 142 is not particularly limited, and an appropriate temperature difference can be set by conducting evaluation experiments based on this disclosure, as in the first embodiment, as needed.

[0054] The embodiments described above are just one embodiment of the technology disclosed herein and do not limit the forms for carrying out the technology.

[0055] In the first and second embodiments, the separators 16 and 18 of the cell precursor 30 are cooled and pressurized to seal the portion of the cell precursor 30 to be sealed (the portion interposed with a thermoplastic resin such as the resin frame 14), but the embodiment is not limited to this. In order to suppress warping of the cell 10, a cooling surface that contacts and cools the separators 16 and 18 in areas where a thermoplastic resin is not interposed and sealing is not intended may be provided. Figure 6 shows the surfaces to be cooled 50 and 52 on surface A of the cell precursor 30 that are not intended to be sealed. For example, by providing the upper molds 42 and 142 with cooling surfaces 42a, 142c, and 142d that have cooling portions that cool the surfaces to be cooled 50 and 52, which are areas where a thermoplastic resin is not interposed, the cooling effect on surfaces A and B of the cell precursor 30 can be made uniform, thereby suppressing or avoiding warping. The cooling surfaces 42a, 142c, and 142d of these upper molds 42 and 142 are examples of a first surface disclosed herein, which includes a surface for cooling a region where a thermoplastic resin is interposed and a surface for cooling a region where the thermoplastic resin is not interposed. Similarly, a surface to be cooled where the thermoplastic resin is not interposed can be set as the B surface of the cell precursor 30, and a second cooling surface can be provided, which includes a surface for cooling a region where a thermoplastic resin is interposed and a surface for cooling a region where the thermoplastic resin is not interposed.

[0056] Furthermore, by appropriately arranging areas on the first and second cooling surfaces where plastic resin is not interposed and sealing is not intended, such as the cooled surfaces 50 and 52 in Figure 6, the same effect as if a temperature difference were generated in the upper molds 42 and 142 and the lower molds 44 and 144 can be obtained without generating a temperature difference in the upper molds 42 and 142 and the lower molds 44 and 144.

[0057] In the first and second embodiments, the thermoplastic resin used to join MEGA12 and separators 16 and 18 is defined as at least a part of the resin frame 14, but it is not limited to this. The joining may be done with a thermoplastic resin agent such as a thermoplastic adhesive provided separately from the resin frame 14, and such thermoplastic resin may be heated and cooled.

[0058] In the first and second embodiments, the upper molds 42, 142a, and 142b are cooled to a lower temperature than the lower molds 44, and 144, but the embodiment is not limited to this. Depending on the shape of the cooling surfaces 42a, 142c, 142d, 44a, and 144a, the contact area with the cell precursor 30, etc., the lower molds 44, and 144 can also be cooled to a lower temperature than the upper molds 42, 142a, and 142b.

[0059] In the first and second embodiments, the upper molds 42, 142a, 142b and the lower molds 44, 144 are cooled to a predetermined temperature beforehand, and the cooling press process is carried out. However, the embodiment is not limited to this. For example, cooling or heating may occur during the cooling press time of the cooling press process. Furthermore, such cooling and heating may result in a temperature difference being generated in at least a portion of the entire cooling surface. In addition, a temperature difference can be generated by varying the cooling rate or heating rate, or by varying the cooling start time or heating start time.

[0060] In the first and second embodiments, the upper molds 42, 142a, 142b and the lower molds 44, 144 are cooled to different predetermined temperatures, but the embodiment is not limited to this. For example, the cooling surface 42a of the upper mold 42, etc., may be cooled in such a way that the temperature difference is continuous, i.e., the temperature is sloped.

[0061] In the first and second embodiments, the cooling press step for cooling the thermoplastic resin of the cell precursor 30 involves creating a temperature difference in at least a portion of the heating surface, which is the contact surface of the cooling press mold with respect to the cell precursor 30. However, the embodiment is not limited to this. For example, in the heating press step for the cell precursor 30, a temperature difference may be created in at least a portion of the first heating surface and the second heating surface. This also provides the same effect as that obtained by creating a temperature difference in at least a portion of the first cooling surface and the second cooling surface in the cooling press step. In addition, in both the heating press step and the cooling press step, a temperature difference may be created in at least a portion of the respective contact surfaces of the heating press mold and the cooling press mold.

[0062] In addition, various methods for generating a temperature difference between the heating surface of the upper die and the heating surface of the lower die of the heating press mold during the heating press process can be the same as those used in the cooling press process in the first and second embodiments, as well as the various methods additionally described above.

[0063] Although embodiments have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness. [Explanation of symbols]

[0064] 10: Cell, 12: MEGA, 14: Resin frame, 16, 18: Separator, 30: Cell precursor, 40, 140: Cooling press mold, 42, 142a, 142b: Upper mold, 44, 144: Lower mold, 42a, 44a, 142c, 142d, 44a, 144a: Cooling surface

Claims

1. A method for manufacturing a fuel cell, A step of preparing a cell precursor comprising: an assembly of the membrane-electrode-gas diffusion layer of the fuel cell; a pair of separators arranged to sandwich the assembly; and a thermoplastic resin interposed between the assembly and the pair of separators; A heating step of heating the thermoplastic resin using a first heating type and a second heating type that are arranged opposite each other and capable of heating the cell precursor, A cooling step of cooling the thermoplastic resin using a first cooling type and a second cooling type that are arranged opposite each other and capable of cooling the cell precursor, Equipped with, The first cooling type has a first cooling surface that can contact and cool the first surface of the cell precursor, The second cooling type has a second cooling surface that can contact and cool the second surface of the cell precursor, The aforementioned cooling process is When the contact area of ​​the first portion of the first cooling surface with the cell precursor is smaller than the contact area of ​​the second portion of the second cooling surface facing the first portion with the cell precursor, the temperature of at least the first portion is cooled to be lower than that of the second portion. When the contact area of ​​the second portion is smaller than the contact area of ​​the first portion, the temperature of the second portion is cooled to a lower temperature than that of the first portion. Manufacturing method.

2. The manufacturing method according to claim 1, wherein the cooling step is a step of using one or both of the first cooling mold having a first cooling surface including a surface for cooling a region in which the thermoplastic resin is interposed and a surface for cooling a region in which the thermoplastic resin is not interposed, and the second cooling mold having a second cooling surface including a surface for cooling a region in which the thermoplastic resin is interposed and a surface for cooling a region in which the thermoplastic resin is not interposed.

3. A fuel cell manufacturing apparatus, A cell precursor comprising a membrane-electrode-gas diffusion layer assembly of the fuel cell, a pair of separators arranged to sandwich the assembly, and a thermoplastic resin interposed between the assembly and the separators, is provided with a first heating element and a second heating element arranged opposite each other to heat the thermoplastic resin of the cell precursor, To cool the thermoplastic resin of the cell precursor, a first cooling type and a second cooling type are arranged opposite each other, A temperature control device for cooling the first cooling type and the second cooling type, Equipped with, The first cooling type has a first cooling surface that can contact and cool the first surface of the cell precursor, The second cooling type has a second cooling surface that can contact and cool the second surface of the cell precursor, The temperature control device is When the contact area of ​​the first portion of the first cooling surface with the cell precursor is smaller than the contact area of ​​the second portion of the second cooling surface facing the first portion with the cell precursor, the temperature of at least the first portion is cooled to be lower than that of the second portion. When the contact area of ​​the second portion is smaller than the contact area of ​​the first portion, the temperature of the second portion is cooled to a lower temperature than that of the first portion. Manufacturing equipment.

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