Method and mold for forming a seal on a flow field plate of an electrochemical cell

Abstract

A method for forming a seal on a flow field plate of an electrochemical cell is presented. The method comprises the following steps: providing a mold comprising a rigid part and a flexible part connected with the rigid part; the mold is arranged on the flow field plate in the mode that the rigid part is pressed against the bottom wall of the groove of the flow field plate, and the flexible part is at least pressed against the top wall of the ridge part, adjacent to the groove, of the flow field plate, so that a glue injection cavity is defined by the bottom wall of the groove, the side wall shared by the groove and the ridge part, the rigid part and the flexible part; sealant is injected into the sealant injection cavity; and curing the sealant to form a sealing part, and removing the mold. The present application also proposes a mold for forming a seal on a flow field plate of an electrochemical cell. According to the method and the mold provided by the invention, the sealing part tightly attached to the side wall of the groove can be formed on the flow field plate of the electrochemical battery, so that the sealing reliability is improved.

Description

Technical Field

[0001] The present application relates generally to the field of electrochemical cell technology, and more particularly to a method and a mold for forming a seal on a flow field plate of an electrochemical cell. Background Art

[0002] With the development of new energy technologies, the use of electrochemical cells as power sources is gaining increasing attention from researchers and the market. Proton exchange membrane fuel cells (PEMFCs) are a widely used electrochemical cell. PEMFCs use hydrogen as fuel and oxygen as oxidant, and generate electricity using the electrochemical reaction of fuel and oxidant. The PEMFC stack generally includes a plurality of battery cells stacked on each other, and each battery cell, except for the battery cells at the ends, includes two bipolar plates shared with adjacent battery cells and a membrane electrode assembly (MEA) sandwiched between the two bipolar plates. Each bipolar plate generally includes two monopolar plates stacked on each other, i.e., an anode plate and a cathode plate. Each monopolar plate includes alternating ridges and grooves to form a flow field for circulating a reaction fluid (fuel or oxidant) and a coolant. Each ridge includes a top wall, and each groove includes a bottom wall, and adjacent ridges and grooves on the same side of the monopolar plate share a side wall, so that the side wall connects the top wall of the ridge and the bottom wall of the groove.

[0003] During the manufacture of the battery cell, it is necessary to form a seal in the groove of the monopolar plate or the bipolar plate composed of two monopolar plates, so that a contact seal is formed by squeezing the seal (for example, by squeezing the seal between the bipolar plate and the MEA) when assembling the battery stack. This can, for example, prevent the coolant and the reaction fluid or the fuel and the oxidant from interpenetrating through the common pipelines of each battery cell, or prevent the reaction fluid or the coolant from leaking outside the battery stack. It is desirable to make the seal fit the side wall of the groove tightly when assembling the battery stack to avoid leaving a gap between the seal and the side wall of the groove.

[0004] A common technique for forming a seal is to set a prefabricated solid seal in the groove. The cross-sectional profile of such a solid seal is usually rectangular. Due to the manufacturing tolerances of the monopolar plate or the solid seal, it is difficult to ensure that the solid seal can fit tightly against the side wall of the groove when assembling the battery stack. Another common technique is to set a rigid mold on the groove so that the groove and the rigid mold enclose a glue injection cavity; then, inject liquid sealant into the glue injection cavity and solidify it to form a seal. In order to ensure a reliable seal between the groove and the rigid mold during the injection of the liquid sealant, the rigid mold is pressed against the bottom wall of the groove. This causes the side wall of the rigid mold to separate the glue injection cavity from the side wall of the groove, resulting in a gap between the formed seal and the side wall of the groove. This makes it difficult to ensure that the seal can fit tightly against the side wall of the groove when assembling the battery stack. If the seal does not fit tightly against the side wall of the groove when assembling the battery stack, it will result in a poor seal. Summary of the invention

[0005] The purpose of the present application is to provide a method and a mold for forming a sealing portion on a flow field plate of an electrochemical cell. The method and the mold according to the present application can overcome the defects in the above-mentioned prior art.

[0006] On the one hand, the present application proposes a method for forming a sealing portion on a flow field plate of an electrochemical cell, wherein the flow field plate includes alternating ridges and grooves, each ridge includes a top wall, and each groove includes a bottom wall, and adjacent ridges and grooves on the same side of the flow field plate share a side wall, so that the side wall connects the top wall of the ridge and the bottom wall of the groove, and the method includes: providing a mold, the mold including a rigid part and a flexible part connected to the rigid part; arranging the mold on the flow field plate in such a manner that the rigid part presses against the bottom wall of the groove, and the flexible part presses against at least the top wall of the ridge adjacent to the groove, so that the bottom wall of the groove, the side wall shared by the groove and the ridge, the rigid part and the flexible part enclose a glue injection cavity; injecting sealant into the glue injection cavity; and curing the sealant to form a sealing portion, and removing the mold.

[0007] In some embodiments, the flow field plate includes a first side and a second side opposite in a first thickness direction, the bottom wall and the top wall are spaced apart from each other by a first distance in the first thickness direction; the mold defines a second thickness direction, the rigid portion includes a first surface configured to engage with the bottom wall, and the flexible portion includes a second surface configured to engage with the top wall; when the mold is not disposed on the flow field plate, the second surface is retracted by a second distance relative to the first surface in the second thickness direction, the second distance being less than the first distance; and when the mold is disposed on the flow field plate in the manner described, the second thickness direction coincides with the first thickness direction, the first surface engages with the bottom wall, and the second surface engages with the top wall, so that the flexible portion is elastically deformed, and the second surface is retracted by a third distance relative to the first surface in the second thickness direction, the third distance being equal to the first distance.

[0008] In some embodiments, the rigid part includes a first rigid section and a second rigid section extending from the first rigid section toward the flexible part, the first rigid section including the first surface; the second rigid section includes a third surface indented relative to the first surface in the second thickness direction, when the mold is arranged on the flow field plate in the manner described, the second rigid section extends above the bottom wall, and the third surface and the bottom wall are opposite to each other and spaced apart from each other in the first thickness direction; the second rigid section also includes a groove recessed from the third surface along the second thickness direction into the second rigid section, the groove is configured to extend along the same extension direction as the groove, the bottom of the groove is spaced apart from the first surface in the second thickness direction by a fourth distance, the fourth distance being greater than the first distance; and injecting the sealant into the injection cavity includes filling the groove with the sealant.

[0009] In some embodiments, the cross section of the groove perpendicular to the extension direction is tapered, preferably a semicircle, an isosceles triangle or an isosceles trapezoid.

[0010] In some embodiments, the third surface is setback relative to the first surface by a fifth distance in the second thickness direction, and the fifth distance is equal to the first distance.

[0011] In some embodiments, the bottom wall is flat and perpendicular to the first thickness direction, and the first surface is flat and perpendicular to the second thickness direction.

[0012] In some embodiments, the mold is an end-to-end annular piece and the flexible portion presses only against the top wall of the ridge.

[0013] In some embodiments, the mold includes a first end and a second end opposite to each other, the flexible part includes a first flexible segment and a second flexible segment extending between the first end and the second end, respectively, the first flexible segment includes the second surface, and the second flexible segment extends from the first flexible segment toward the rigid part, the second flexible segment includes a fourth surface indented relative to the first surface in the second thickness direction, the flexible part also includes a third flexible segment extending beyond the fourth surface along the second thickness direction at at least one of the first end and the second end, when the mold is arranged on the flow field plate in the described manner, the second flexible segment extends above the side wall and the bottom wall, the fourth surface is opposite to and spaced apart from the side wall and the bottom wall in the first thickness direction, and the third flexible segment is at least pressed against the side wall, preferably against the side wall and the bottom wall.

[0014] In some embodiments, the flow field plate includes ridges and grooves on both the first side and the second side, and the ridges and grooves are formed in such a manner that the same plate segment of the flow field plate defines one of the grooves and the ridges on the first side and defines the other of the grooves and the ridges on the second side, and for the grooves and the ridges defined by the same plate segment, the bottom wall of the groove is common to the top wall of the ridge, and the side wall of the groove is common to the side wall of the ridge; the flow field plate includes a first groove, a second groove, and a third ridge between the first groove and the second groove on the first side, and a third ridge between the first groove and the second groove on the second side. A first ridge, a second ridge and a third groove are respectively formed on the flow field plate and correspond to the first groove, the second groove and the third ridge; a portion of the third ridge is interrupted to form a connecting portion connecting the first groove with the second groove on the first side, and a blocking portion blocking the third groove is formed on the second side; and the method includes forming a sealing portion at the connecting portion in the second groove through the mold to block the connection between the first groove and the second groove via the connecting portion. Preferably, the first groove is located in a reaction zone of the flow field plate for circulating a reaction fluid, and the second groove is located outside the reaction zone.

[0015] On the other hand, the present application proposes a mold for forming a sealing portion on a flow field plate of an electrochemical cell, the flow field plate comprising alternating ridges and grooves, each ridge comprising a top wall, and each groove comprising a bottom wall, and adjacent ridges and grooves on the same side of the flow field plate share a side wall, so that the side wall connects the top wall of the ridge and the bottom wall of the groove, and the mold comprises a rigid portion and a flexible portion connected to the rigid portion. The mold is configured to be arranged on the flow field plate in such a manner that the rigid portion presses against the bottom wall of the groove, and the flexible portion presses against at least the top wall of the ridge adjacent to the groove, so that the bottom wall of the groove, the side wall shared by the groove and the ridge, the rigid portion, and the flexible portion enclose a glue injection cavity.

[0016] In some embodiments, the flow field plate includes a first side and a second side opposite in a first thickness direction, the bottom wall and the top wall are spaced apart from each other by a first distance in the first thickness direction; the mold defines a second thickness direction, the rigid portion includes a first surface configured to engage with the bottom wall, and the flexible portion includes a second surface configured to engage with the top wall; when the mold is not disposed on the flow field plate, the second surface is retracted by a second distance relative to the first surface in the second thickness direction, the second distance being less than the first distance; and when the mold is disposed on the flow field plate in the manner described, the second thickness direction coincides with the first thickness direction, the first surface engages with the bottom wall, and the second surface engages with the top wall, so that the flexible portion is elastically deformed, and the second surface is retracted by a third distance relative to the first surface in the second thickness direction, the third distance being equal to the first distance.

[0017] In some embodiments, the rigid portion includes a first rigid section and a second rigid section extending from the first rigid section toward the flexible portion, the first rigid section including the first surface; the second rigid section includes a third surface indented relative to the first surface in the second thickness direction, when the mold is arranged on the flow field plate in the manner described, the second rigid section extends above the bottom wall, and the third surface and the bottom wall are opposite to and spaced apart from each other in the first thickness direction; and the second rigid section also includes a groove recessed from the third surface into the second rigid section along the second thickness direction, the groove being configured to extend along the same extension direction as the groove, the bottom of the groove being spaced apart from the first surface by a fourth distance in the second thickness direction, the fourth distance being greater than the first distance.

[0018] In some embodiments, the cross section of the groove perpendicular to the extension direction is tapered, preferably a semicircle, an isosceles triangle or an isosceles trapezoid.

[0019] In some embodiments, the third surface is setback relative to the first surface by a fifth distance in the second thickness direction, and the fifth distance is equal to the first distance.

[0020] In some embodiments, the bottom wall is flat and perpendicular to the first thickness direction, and the first surface is flat and perpendicular to the second thickness direction.

[0021] In some embodiments, the mold is an end-to-end annular piece and the flexible portion presses only against the top wall of the ridge.

[0022] In some embodiments, the mold includes a first end and a second end opposite to each other, the flexible part includes a first flexible segment and a second flexible segment extending between the first end and the second end, respectively, the first flexible segment includes the second surface, and the second flexible segment extends from the first flexible segment toward the rigid part, the second flexible segment includes a fourth surface indented relative to the first surface in the second thickness direction, the flexible part also includes a third flexible segment extending beyond the fourth surface along the second thickness direction at at least one of the first end and the second end, when the mold is arranged on the flow field plate in the described manner, the second flexible segment extends above the side wall and the bottom wall, the fourth surface is opposite to and spaced apart from the side wall and the bottom wall in the first thickness direction, and the third flexible segment is at least pressed against the side wall, preferably against the side wall and the bottom wall.

[0023] According to the method and mold of the present application, a sealing portion that closely fits the side wall of the groove can be formed on the flow field plate of the electrochemical cell, thereby improving the sealing reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other aspects of the present application will be more thoroughly understood and appreciated in conjunction with the accompanying drawings. It should be noted that the drawings are schematic only and are not drawn to scale. In different drawings, the same parts are represented by the same figure numbers. In addition, for the sake of brevity, not all parts or parts of the molds, monopolar plates and bipolar plates according to the present application are shown or marked in the drawings. It should be understood that the size, proportional relationship and number of parts of each part or part in the drawings are not intended to limit the present application. In the drawings:

[0025] Figure 1A is a top plan view of a monopolar plate according to some embodiments of the present application;

[0026] Figure 1B yes Figure 1A An enlarged view of the dotted lined area 1B;

[0027] Figure 1C yes Figure 1A The monopolar plate is along Figure 1B A partial cross-sectional view taken along line II in FIG.

[0028] Figure 2A According to some embodiments of the present application, Figure 1A A three-dimensional view of a mold for forming a sealing portion on a monopolar plate shown;

[0029] Figure 2B yes Figure 2A Another stereoscopic view of the mold;

[0030] Figure 2C yes Figure 2A Along the mold Figure 2A A cross-sectional view taken along line II-II in FIG.

[0031] Figure 3A is a partial cross-sectional view of a bipolar plate according to some embodiments of the present application, the bipolar plate is composed of Figure 1A A monopolar plate having a similar configuration is formed with another monopolar plate;

[0032] FIG. 3B to FIG. 3E The partial cross-section schematically shows the use of Figure 2A The mold shown and another mold having a similar configuration are Figure 3A A process for forming a sealing portion on a bipolar plate, wherein: Figure 3B The mold is shown aligned with the grooves of the bipolar plate but not positioned on the bipolar plate; Figure 3C It is shown that the mold is set on the bipolar plate to enclose the glue injection cavity, but the sealant is not injected into the glue injection cavity; Figure 3D It shows that the mold is set on the bipolar plate, and the sealant is injected into the injection cavity; Figure 3E The sealant is shown cured to form a seal, and the mold is removed;

[0033] Figure 4 It shows two Figure 3E A stack of bipolar plates and membrane electrode assemblies sandwiched therebetween; and

[0034] Figure 5 is with Figure 1B A similar enlarged view but showing a seal formed on the unipolar plate. DETAILED DESCRIPTION

[0035] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the following embodiments, monopolar plates and bipolar plates for PEMFC are used as examples of flow field plates of electrochemical cells to describe the method and mold for forming a sealing portion according to the present application. However, it should be understood that these exemplary embodiments do not mean that any limitation is formed on the present application. In addition, the various features in the embodiments of the present application can be combined with each other without conflict.

[0036] Figures 1A to 1C A monopolar plate 1 according to some embodiments of the present application is schematically shown. Figure 1A is a top plan view of the monopolar plate 1, Figure 1B yes Figure 1A An enlarged view of the dotted lined area 1B, and Figure 1C It is along the monopolar plate 1 Figure 1B A partial cross-sectional view taken along line II in FIG.

[0037] For the sake of clarity and simplicity of description, a transverse direction XX, a longitudinal direction YY and a vertical direction ZZ are defined. The transverse direction XX, the longitudinal direction YY and the vertical direction ZZ are perpendicular to each other. The transverse direction XX generally refers to the length direction of the monopolar plate 1, the longitudinal direction YY generally refers to the width direction of the monopolar plate 1, and the vertical direction ZZ generally refers to the thickness direction of the monopolar plate 1.

[0038] The monopolar plate 1 can be configured for a proton exchange membrane fuel cell (PEMFC). PEMFC uses hydrogen as fuel and oxygen as oxidant. The PEMFC stack (not shown) is used to convert the chemical energy in the fuel and oxidant into electrical energy. Generally, hydrogen is called "anode reaction gas", and oxygen or air is called "cathode reaction gas". The PEMFC stack generally includes a plurality of battery cells stacked on each other, and each battery cell, except for the battery cells at the ends, includes two bipolar plates shared with adjacent battery cells and a membrane electrode assembly (MEA) sandwiched between the two bipolar plates. Each bipolar plate includes two monopolar plates stacked on each other, i.e., an anode plate and a cathode plate. The monopolar plate 1 can be used as an anode plate or a cathode plate. In addition, the coolant from the thermal management system of the PEMFC can flow through the battery cell for temperature control. The configuration of the monopolar plate 1 is specifically described below by taking the example that the monopolar plate 1 is configured to be used as an anode plate.

[0039] like Figure 1A and Figure 1C As shown, the monopolar plate 1 may be a substantially rectangular plate, and includes a first side 11 and a second side 12 opposite to each other in a vertical direction ZZ (the direction may also be referred to as a thickness direction or a first thickness direction of the monopolar plate 1), an anode inlet hole 21 configured to receive an anode reaction gas, an anode outlet hole 22 configured to discharge an anode reaction product, a cathode inlet hole 23 configured to receive a cathode reaction gas, a cathode outlet hole 24 configured to discharge a cathode reaction product, a coolant inlet hole 25 configured to receive a coolant, and a coolant outlet hole 26 configured to discharge the coolant. The anode inlet hole 21, the anode outlet hole 22, the cathode inlet hole 23, the cathode outlet hole 24, the coolant inlet hole 25, and the coolant outlet hole 26 extend from the first side 11 to the second side 12 along the vertical direction ZZ, respectively.

[0040] like Figure 1A As shown, the monopolar plate 1 includes an anode flow field 30 formed on the first side 11. Specifically, as Figure 1B and Figure 1CAs shown, the monopolar plate 1 includes alternating ridges 41 and grooves 42 on the first side 11. Each ridge 41 includes a top wall 41a, and each groove 42 includes a bottom wall 42a, and adjacent ridges 41 and grooves 42 share a side wall 43, so that the side wall 43 connects the top wall 41a of the ridge 41 and the bottom wall 42a of the groove 42. Some of the grooves 42 can be configured to extend between the anode inlet channel 21 and the anode outlet channel 22, and connect the anode inlet channel 21 and the anode outlet channel 22, thereby forming an anode flow field 30.

[0041] Please continue to see Figure 1A The anode flow field 30 includes a flow direction along the reaction gas (eg Figure 1A The inlet distribution area 31, the reaction area 32 and the outlet collection area 33 are sequentially arranged (schematically represented by multiple dotted arrows 50 in FIG. 1 ). The inlet distribution area 31 is configured to be arranged near the anode inlet channel 21 and communicate with the anode inlet channel 21 to receive the anode reaction gas from the anode inlet channel 21. The outlet collection area 33 is configured to be arranged near the anode outlet channel 22 and communicate with the anode outlet channel 22 to discharge the reaction product to the anode outlet channel 22. The anode reaction gas can flow from the anode inlet channel 21 to the reaction area 32 via the inlet distribution area 31 of the anode flow field 30, and participate in the reaction in the reaction area 32. The anode reaction product (and the anode reaction gas that is not completely consumed) can flow from the reaction area 32 to the outlet collection area 33, and be discharged from the anode outlet channel 22.

[0042] Although not specifically shown in the figure, it is conceivable that, similar to the anode flow field 30 on the first side 11, the monopolar plate 1 also includes a coolant flow field formed on the second side 12 and used to circulate the coolant. Figure 1C As schematically shown, the unipolar plate 1 may include alternating ridges 61 and grooves 62 on the second side 12. Some of the grooves 62 may be configured to extend between the coolant inlet holes 25 and the coolant outlet holes 26 and connect the coolant inlet holes 25 and the coolant outlet holes 26 to form a coolant flow field.

[0043] For example, in Figure 1C In the illustrated embodiment, the ridges (ridges 41 on the first side 11 and ridges 61 on the second side 12) and grooves (grooves 42 on the first side 11 and grooves 62 on the second side 12) of the monopolar plate 1 can be formed in such a manner that the same plate segment of the monopolar plate 1 defines one of the grooves and ridges on the first side 11 and defines the other of the grooves and ridges on the second side 12, and for the grooves and ridges defined by the same plate segment, the bottom wall of the groove is shared with the top wall of the ridge, and the side wall of the groove is shared with the side wall of the ridge. Figure 1CAs shown, a plate segment 10a of the monopolar plate 1 defines a groove 42 on the first side 11 and a ridge 61 on the second side 12. For the groove 42 and the ridge 61 defined by the plate segment, the bottom wall of the groove 42 and the top wall of the ridge 61 are common, that is, they are the same wall (the wall is Figure 1C The sidewalls of the groove 42 and the sidewalls of the ridge 61 are common, that is, the same walls (these walls are Figure 1C Please continue to refer to Figure 1C , another plate segment 10b or 10c of the monopolar plate 1 adjacent to the plate segment 10a defines a ridge 41 on the first side 11 and defines a groove 62 on the second side 12. For the groove 62 and the ridge 41 defined by the other plate segment 10b or 10c, the bottom wall of the groove 62 and the top wall of the ridge 41 are common, that is, they are the same wall (the wall is Figure 1C The sidewalls of the groove 62 and the sidewalls of the ridge 41 are common, that is, the same walls (these walls are Figure 1C 43). The groove 62 and the ridge 41 correspond to each other in the vertical direction ZZ, and the groove 42 and the ridge 61 correspond to each other in the vertical direction ZZ. For the same plate segment of the monopolar plate 1, a groove is defined on the first side 11 and a ridge is defined on the second side 12, or a ridge is defined on the first side 11 and a groove is defined on the second side 12. In addition, as described above, the grooves and ridges on the same side (i.e., the grooves 42 and the ridges 41, the grooves 62 and the ridges 61) share side walls, so that the side walls connect the top wall of the ridge and the bottom wall of the groove. The monopolar plate 1 having such ridges and grooves can be made by any suitable process such as stamping or molding. For example, the monopolar plate 1 can be made of a material such as stainless steel by a stamping process. For another example, the monopolar plate 1 can be formed in such a way that a porous layered expanded graphite is used as a substrate, a resin is used as a binder, and it is made by a molding process. It should be understood that the present application is not limited thereto.

[0044] It should be understood that the ridges and grooves on the first side 11 and the second side 12 of the monopolar plate 1 are not limited to the above-mentioned forms. For example, in other embodiments, the monopolar plate 1 having ridges and grooves can be formed by a machining process. In this case, for the same plate segment of the monopolar plate 1, grooves can be defined on both the first side 11 and the second side 12, or ridges can be defined on both the first side 11 and the second side 12. In addition, the ridges and grooves on the first side 11 and the second side 12 of the monopolar plate 1 may correspond to each other or not correspond to each other in the vertical direction ZZ.

[0045] Although the above combination Figures 1A to 1CThe configuration of the unipolar plate 1 is specifically described by taking the example that the unipolar plate 1 is configured to be used as an anode plate, but it should be understood that the unipolar plate 1 can be configured to be used as a cathode plate. In the case where the unipolar plate 1 is configured to be used as a cathode plate, the unipolar plate 1 can include grooves or ridges similar to the grooves and ridges described above to include a cathode flow field on one side (which is similar to the anode flow field 30, except that the cathode flow field extends between the cathode inlet channel 23 and the cathode outlet channel 24) and a coolant flow field on the other side. Those skilled in the art should be able to conceive of the configuration of the unipolar plate 1 configured to be used as a cathode plate, so it will not be repeated here.

[0046] In a PEMFC, the anode plate and the cathode plate are connected together in a manner that the coolant flow fields face each other (i.e., the anode flow field of the anode plate and the cathode flow field of the cathode plate face away from each other) to form a bipolar plate, such as the bipolar plate 10 to be described below. For example, the ridges of the anode plate and the cathode plate on one side of the coolant flow field can be fixed relative to each other by a process such as welding or bonding, and the grooves of the anode plate and the cathode plate on one side of the coolant flow field can enclose a coolant flow channel. The difference between a unipolar plate and a bipolar plate is that a bipolar plate has an anode flow field and a cathode flow field on opposite sides thereof, and the coolant flow channel is located in the bipolar plate, while a unipolar plate has an anode flow field or a cathode flow field only on one side, and a coolant flow field on the opposite side. In the present application, the term "flow field plate" includes unipolar plates and bipolar plates.

[0047] FIG. 3A to FIG. 3E is with Figure 1C A similar schematic partial cross-sectional view, which shows in partial cross-section the Figure 1A The bipolar plate 10 is composed of a monopolar plate 1 and another monopolar plate 1' having a similar configuration. The bipolar plate 10 can be shared by two adjacent battery cells of the PEMFC: the monopolar plate 1 is used as the anode plate (or cathode plate) of one of the battery cells, and the monopolar plate 1' is used as the cathode plate (or anode plate) of the other battery cell. FIG. 3A to FIG. 3E As shown, at this cross-sectional position, the monopolar plate 1' has a symmetrical structure with the monopolar plate 1. FIG. 3A to FIG. 3E The structure of the monopolar plate 1' which is symmetrical to the monopolar plate 1 is indicated by the reference sign "XX'", and will not be described in detail here.

[0048] like Figure 3AAs shown, similar to the monopolar plate 1, the monopolar plate 1' may include a first side 11' and a second side 12' opposite to each other in the vertical direction ZZ (also referred to as the thickness direction of the monopolar plate 1'), ridges 41' and grooves 42' alternating on the first side 11', and ridges 61' and grooves 62' alternating on the second side 12'. The monopolar plate 1 and the monopolar plate 1' are connected together in a manner that the second side 12 of the monopolar plate 1 and the second side 12' of the monopolar plate 1' face each other. For example, the ridge 61 on the second side 12 of the monopolar plate 1 and the ridge 61' on the second side 12' of the monopolar plate 1' can be aligned with each other and fixed relative to each other by a process such as welding or bonding. Accordingly, the groove 62 on the second side 12 of the monopolar plate 1 and the groove 62' on the second side 12' of the monopolar plate 1' can be aligned with each other and enclose a coolant flow channel.

[0049] During the manufacture of the battery cell of the PEMFC, it is necessary to form a sealing portion in the groove of the monopolar plate 1 or 1' or the bipolar plate 10 composed of two monopolar plates 1 and 1', so as to form a contact seal by squeezing the sealing portion (for example, squeezing the sealing portion by the bipolar plate 10 and the MEA) when assembling the stack. This can, for example, prevent the coolant and the reaction fluid or the fuel and the oxidant from interpenetrating through the common pipeline of each battery cell, or prevent the reaction fluid or the coolant from leaking to the outside of the stack. As described in the background technology, it is expected that the sealing portion is closely fitted to the side wall of the groove when assembling the stack to avoid leaving a gap between the sealing portion and the side wall of the groove.

[0050] FIG. 2A to FIG. 2C A mold 100 configured to form a sealing portion on a monopolar plate 1 according to some embodiments of the present application is shown. Figure 2A is a three-dimensional diagram of the mold 100, Figure 2B is another perspective view of the mold 100, and Figure 2C The mold 100 is along Figure 2A The cross-sectional view taken along the line II-II in FIG. FIG. 2A to FIG. 2C As shown, the mold 100 includes a rigid portion 110, a flexible portion 120 connected to the rigid portion 110, and a glue injection hole 130 extending through the mold 100. As will be described in detail below, the glue injection hole 130 extends through the mold 100 to connect the glue injection cavity 200 enclosed by at least the mold 100 and the monopolar plate 1 with the outside of the mold 100, thereby allowing the liquid sealant 80 to be injected into the glue injection cavity 200 through the glue injection hole 130.

[0051] The rigid part 110 may be made of a rigid material or a semi-rigid material. A rigid or semi-rigid material refers to a material that does not deform or hardly deforms under an external force. For example, a rigid or semi-rigid material may be a metal or a ceramic. It should be understood that the present application is not limited thereto.

[0052] The flexible portion 120 may be made of an elastic material. An elastic material refers to a material that undergoes elastic deformation under the action of an external force and thus restores its shape before deformation when the external force is removed. For example, the elastic material may be rubber. It should be understood that the present application is not limited thereto.

[0053] The rigid part 110 and the flexible part 120 of the mold 100 can be connected together by any suitable means. For example, the rigid part 110 and the flexible part 120 can be bonded or heat-melted together. For another example, the rigid part 110 and the flexible part 120 can include mechanisms that cooperate with each other to connect the rigid part 110 and the flexible part 120 together.

[0054] The sealant 80 may be any suitable type of sealant that is suitable for being injected into the injection cavity 200 to form a sealing portion, for example, a silicone sealant, a fluororubber sealant, or a polyolefin material (such as EPDM).

[0055] FIG. 3B to FIG. 3E The process of forming the sealing portion 81 on the first side 11 of the monopolar plate 1 by using the mold 100 is schematically shown in partial cross-section, wherein: Figure 3B The mold 100 is shown to be aligned with the groove 42 of the monopolar plate 1 , but not disposed on the monopolar plate 1 ; Figure 3C It is shown that the mold 100 is arranged on the monopolar plate 1 to enclose a glue injection cavity 200 with the monopolar plate 1; Figure 3D It shows that the liquid sealant 80 is injected into the injection cavity 200 via the injection hole 130; Figure 3E The liquid sealant 80 is shown to be cured to form the sealing portion 81, and the mold 100 is removed from the monopolar plate 1. FIG. 3B to FIG. 3E As shown, the method for forming a sealing portion 81 on a monopolar plate 1 according to the present application may include: providing a mold 100; setting the mold 100 on the monopolar plate 1 to enclose a glue injection cavity 200 with the monopolar plate 1; injecting the sealant 80 into the glue injection cavity 200; and curing the sealant 80 to form the sealing portion 81, and removing the mold 100.

[0056] like Figure 3CAs best shown, the mold 100 is configured to be arranged on the monopolar plate 1 in such a manner that the rigid portion 110 is pressed against the bottom wall 42a of the groove 42, and the flexible portion 120 is pressed against at least the top wall 41a of the ridge 41 adjacent to the groove 42, so that the bottom wall 42a of the groove 42, the side wall 43 shared by the groove 42 and the ridge 41, the rigid portion 110 and the flexible portion 120 enclose a glue injection cavity 200. That is, a seal is formed between the rigid portion 110 and the bottom wall 42a and between the flexible portion 120 and at least the top wall 41a. With this configuration of the glue injection cavity 200, the formed sealing portion 81 can be made to fit closely to the side wall 43 of the groove 42, thereby improving the sealing reliability. When assembling the PEMFC stack, by squeezing such a sealing portion 81 (for example, squeezing the sealing portion 81 by adjacent bipolar plates and MEA), a reliable seal that fits closely to the side wall 43 can be formed.

[0057] In some embodiments, pressure can be applied to the rigid portion 110 and the flexible portion 120 by any suitable mechanism such as a clamp so that the rigid portion 110 is pressed against the bottom wall 42a of the groove 42, and the flexible portion 120 is pressed against at least the top wall 41a of the ridge 41 adjacent to the groove 42, thereby forming a glue injection cavity 200.

[0058] Please return to see Figure 1B and Figure 1C , the bottom wall 42a of the groove 42 of the monopolar plate 1 and the top wall 41a of the adjacent ridge 41 are spaced apart from each other by a first distance D1 in the vertical direction ZZ. The first distance D1 may be referred to as the depth of the groove 42 or the height of the ridge 41. The groove 42 and the ridge 41 of the monopolar plate 1 each extend along an extension direction perpendicular to the vertical direction ZZ. For example, the extension direction may be different at different locations of the groove 42 and / or the ridge 41. Therefore, the extension direction may be the same as or different from the transverse direction XX and the longitudinal direction YY. As Figure 1C As best shown, the first distance D1 is the distance that the bottom wall 42a of the groove 42 and the top wall 41a of the adjacent ridge 41 are spaced apart from each other in the vertical direction ZZ in the same cross section perpendicular to the extension direction (or, in other words, along the vertical direction ZZ).

[0059] like FIG. 2A to FIG. 2C As shown, the mold 100 may define a length direction, a width direction, and a thickness direction. FIG. 3B to FIG. 3D As shown, when the mold 100 is arranged on the monopolar plate 1 in the aforementioned manner, the length direction of the mold 100 coincides with the length direction of the monopolar plate 1, the width direction of the mold 100 coincides with the width direction of the monopolar plate 1, and the thickness direction of the mold 100 coincides with the thickness direction of the monopolar plate 1. Therefore, for the sake of clarity and simplicity of description, FIG. 2A to FIG. 2C and FIG. 3B to FIG. 3D In the figure, the length direction, width direction and thickness direction of the mold 100 are indicated by the transverse direction XX, the longitudinal direction YY and the vertical direction ZZ respectively.

[0060] like FIG. 2A to FIG. 2C and FIG. 3B to FIG. 3D As shown, the rigid portion 110 includes a first surface 111 configured to engage with the bottom wall 42a of the groove 42, and the flexible portion 120 includes a second surface 122 configured to engage with the top wall 41a of the adjacent ridge 41. Figure 2C As best shown, when the mold 100 is not disposed on the monopolar plate 1, the second surface 122 of the flexible portion 120 is retracted a second distance D2 relative to the first surface 111 of the rigid portion 110 in the vertical direction ZZ (i.e., the thickness direction of the mold 100, which may also be referred to as the second thickness direction). The rigid portion 110 and the flexible portion 120 of the mold 100 extend along an extension direction perpendicular to the vertical direction ZZ. It should be understood that the shapes of the rigid portion 110 and the flexible portion 120 may be formed in accordance with the shapes of the grooves 42 and ridges 41 to be matched. Therefore, similar to the grooves 42 and the ridges 41, the extension direction may be different at different locations of the rigid portion 110 and the flexible portion 120. The extension direction may be the same as or different from the lateral direction XX and the longitudinal direction YY. As Figure 2C As best shown, the second distance D2 is the distance that the second surface 122 of the flexible portion 120 is set back relative to the first surface 111 of the rigid portion 110 in the vertical direction ZZ within the same cross section perpendicular to the extension direction (or, in other words, along the vertical direction ZZ).

[0061] In some embodiments, the second distance D2 can be less than the first distance D1. This enables the flexible portion 120 to elastically deform against the ridge 41 in such a way that the second surface 122 engages the top wall 41a of the ridge 41 when the mold 100 is placed on the monopolar plate 1 so that the first surface 111 of the rigid portion 110 engages the bottom wall 42a of the groove 42. This helps to form a tight seal between the second surface 122 of the flexible portion 120 and the top wall 41a of the ridge 41, even without any additional pressure being applied to the flexible portion 120 on the side of the flexible portion 120 opposite to the second surface 122. When the mold 100 is placed on the monopolar plate 1 in the manner described above, the second surface 122 of the flexible portion 120 is retracted by a third distance D3 ( D1) relative to the first surface 111 of the rigid portion 110 in the vertical direction ZZ. Figure 3C Due to the elastic deformation of the flexible portion 120, the third distance D3 is equal to the first distance D1.

[0062] In some embodiments, Figure 2CAs best shown, the second surface 122 of the flexible portion 120 extends from a proximal end adjacent to the rigid portion 110 to a distal end away from the rigid portion 110. When the mold 100 is not disposed on the monopolar plate 1, the second surface 122 may be retracted by a second distance D2 relative to the first surface 111 in the vertical direction ZZ and may decrease monotonically, preferably linearly, from the proximal end toward the distal end. It should be understood that the present application is not limited thereto.

[0063] In some embodiments, Figure 2C As shown, the rigid portion 110 may include a first rigid section 110a and a second rigid section 110b extending from the first rigid section 110a toward the flexible section 120. For example, the second rigid section 110b may connect the first rigid section 110a and the flexible section 120. The first rigid section 110a includes the aforementioned first surface 111. In other words, the first surface 111 of the first rigid section 110a is configured to engage with the bottom wall 42a of the groove 42. The second rigid section 110b includes a third surface 113 that is indented relative to the first surface 111 of the first rigid section 110a in the vertical direction ZZ. Figure 3C As shown, when the mold 100 is disposed on the monopolar plate 1 in the aforementioned manner, the second rigid section 110 b extends above the bottom wall 42 a of the groove 42 , and the third surface 113 and the bottom wall 42 a are opposite to and spaced apart from each other in the vertical direction ZZ.

[0064] In some embodiments, Figure 2C As shown, the second rigid section 110b may include a groove 115 that is recessed into the second rigid section 110b from the third surface 113 along the vertical direction ZZ. Figure 3C As shown, the groove 115 is configured to extend along the same extension direction as the groove 42. Figure 2C , the bottom 115a of the groove 115 is spaced apart from the first surface 111 by a fourth distance D4 in the vertical direction ZZ. Figure 3C As shown, the fourth distance D4 is the distance between the bottom 115a of the groove 115 and the first surface 111 in the vertical direction ZZ in the same cross section perpendicular to the extension direction (or in other words, along the vertical direction ZZ). The fourth distance D4 may be greater than the first distance D1.

[0065] In the method according to the present application, if Figure 3D As shown, injecting the sealant 80 into the injection cavity 200 may include filling the groove 115 with the sealant 80. In this way, as shown in FIG. Figure 3EAs shown, the formed sealing portion 81 can include a protruding rib 81a protruding from the top wall 41a of the ridge 41 in the vertical direction ZZ. The sealing portion 81 is formed with such a protruding rib 81a, which can facilitate the control of the pressing force used to press the sealing portion 81 when assembling the battery stack.

[0066] In some embodiments, the cross-section of the groove 115 perpendicular to the extension direction may be tapered. That is, from the portion of the groove 115 connected to the third surface 113 to the bottom 115a, the cross-section of the groove 115 is tapered. Accordingly, the cross-section of the rib 81a of the formed sealing portion 81 perpendicular to the extension direction is a gradually expanding shape. This makes it possible for the surface area of ​​the sealing portion 81 in contact with the force-applying component to gradually increase during the initial stage of applying the extrusion force when assembling the battery stack, which helps prevent the sealing portion 81 from tilting up and out of contact with the side wall 43. Optionally, the cross-section of the groove 115 perpendicular to the extension direction may be a semicircle, an isosceles triangle or an isosceles trapezoid. These shapes are particularly useful for preventing the sealing portion 81 from tilting up.

[0067] like Figure 2C As shown, the third surface 113 of the second rigid section 110b is retracted by a fifth distance D5 relative to the first surface 111 of the first rigid section 110a in the vertical direction ZZ. The fifth distance D5 is the distance that the third surface 113 of the second rigid section 110b is retracted relative to the first surface 111 of the first rigid section 110a in the vertical direction ZZ in the same cross section perpendicular to the extension direction (or in other words, along the vertical direction ZZ). The fifth distance D5 may be equal to the first distance D1. Figure 3E As shown, through this configuration, the formed sealing portion 81 (except the protruding rib 81a) can be flush with the top wall 41a of the ridge 41. In some other embodiments, the fifth distance D5 can be greater than or less than the first distance D1.

[0068] In some embodiments, FIG. 2A to FIG. 2C As shown, the injection hole 130 can be formed in the second rigid section 110b. It should be understood that the present application is not limited thereto, and the injection hole 130 can be formed at any other suitable position. In addition, although not shown in the drawings, it should be understood that the mold 100 can include an exhaust hole for exhausting the gas in the injection cavity 200 during the injection of the sealant 80 into the injection cavity 200.

[0069] In some embodiments, Figure 1CAs shown, the bottom wall 42a of the groove 42 of the monopolar plate 1 and the top wall 41a of the adjacent ridge 41 are each flat and perpendicular to the vertical direction ZZ. Correspondingly, the first surface 111 of the first rigid section 110a of the rigid part 110 of the mold 100 may also be flat and perpendicular to the vertical direction ZZ. It should be understood that the present application is not limited to this. For example, the bottom wall 42a of the groove 42 of the monopolar plate 1 may be in any other suitable shape, such as a curved shape, and the first surface 111 of the first rigid section 110a of the rigid part 110 of the mold 100 may be configured to cooperate with the bottom wall 42a in shape to form a seal.

[0070] In some embodiments, the mold 100 may be an annular member connected end to end. In this case, the flexible portion 120 of the mold 100 may only be pressed against the top wall 41 a of the ridge 41 , and may not be engaged with the bottom wall 42 a and the side wall 43 of the groove 42 .

[0071] In other embodiments, FIG. 2A to FIG. 2C As shown, the mold 100 may include a first end 100a and a second end 100b opposite to each other. The flexible portion 120 includes a first flexible section 120a and a second flexible section 120b ( Figure 2C ). The first flexible segment 120a includes the aforementioned second surface 122. In other words, the second surface 122 of the first flexible segment 120a is configured to engage with the top wall 41a of the ridge 41. The second flexible segment 120b extends from the first flexible segment 120a toward the rigid portion 110. For example, the second flexible segment 120b can connect the first flexible segment 120a and the second rigid segment 110b of the rigid portion 110. The second flexible segment 120b includes a fourth surface 124 that is retracted relative to the first surface 111 of the first rigid segment 110a in the vertical direction ZZ. The flexible portion 120 may also include a third flexible segment 120c that extends beyond the fourth surface 124 along the vertical direction ZZ at the first end 100a and the second end 100b, respectively. As Figure 3CAs shown, when the mold 100 is arranged on the monopolar plate 1 in the aforementioned manner, the second flexible section 120b extends above the side wall 43 and the bottom wall 42a of the groove 42, and the fourth surface 124 and the side wall 43 and the bottom wall 42a are opposite to each other and spaced apart from each other in the vertical direction ZZ. The third flexible section 120c at the first end 100a is pressed against the side wall 43 and the bottom wall 42a of the groove 42 to form a sealing portion of the closed injection cavity 200. It is conceivable that another third flexible section 120c at the second end 100b can be pressed against the side wall 43 and the bottom wall 42a of the groove 42 to form a sealing portion of the closed injection cavity 200. In other partial embodiments, the third flexible section 120c can be pressed only against the side wall 43 of the groove 42, but not against the bottom wall 42a of the groove 42. Furthermore, the third flexible section 120c may be provided at only one of the first end 100a and the second end 100b, and the mold 100 may be mated with another mold or a stopper at the other end.

[0072] For the monopolar plate 1, it may be necessary to block the flow of fluid in some channels. For example, refer back to Figure 1B and Figure 1C , when the ridges (ridges 41 on the first side 11 and ridges 61 on the second side 12) and the grooves (grooves 42 on the first side 11 and grooves 62 on the second side 12) of the monopolar plate 1 are Figure 1C When the monopolar plate 1 is formed in the manner shown in the figure (i.e., the same plate segment of the monopolar plate 1 defines one of the groove and the ridge on the first side 11, and defines the other of the groove and the ridge on the second side 12, and for the groove and the ridge defined by the same plate segment, the bottom wall of the groove is shared with the top wall of the ridge, and the side wall of the groove is shared with the side wall of the ridge), it may be necessary to block one of the grooves 62 on the second side 12 (at Figure 1C To this end, a portion of the ridge 41 corresponding to the groove 62 on the first side 11 is interrupted (i.e., the ridge 41 is not formed at the position corresponding to the portion), so as to form a connecting portion 91 connecting two adjacent grooves 42 on the first side 11, and a blocking portion 92 (at the second side 12) blocking the groove 62 is formed. Figure 1C and FIG. 3A to FIG. 3E In the embodiment, the blocking portion 92 is omitted on the second side 12. Figure 1C The left groove 62) is located in the reaction zone 32 and the other Figure 1CIn the case where the groove 62 on the right in the middle is located outside the reaction zone 32, if the connecting portion 91 is not blocked, the reaction fluid (here, the anode reaction gas) circulating in the reaction zone 32 will flow into the groove 42 located outside the reaction zone 32 via the connecting portion 91. As an example, this may cause leakage of the reaction fluid. As another example, if there are multiple such connecting portions 91, a bypass channel bypassing the reaction zone 32 will be formed. This will reduce the concentration of the reaction fluid in the reaction zone 32, thereby reducing the power generation efficiency of the battery unit.

[0073] The mold 100 according to the present application can be used to form a sealing portion 81 at the connecting portion 91 to block the connection of the grooves 42 located on both sides of the connecting portion 91 through the connecting portion 91. Specifically, Figure 5 As shown, the mold 100 can be used to FIG. 3B to FIG. 3E The method shown forms a sealing portion 81 in the groove 42 located outside the reaction zone 32 at the connecting portion 91 , which is close to the side wall 43 of the groove 42 , so as to block the connection between the grooves 42 located on both sides of the connecting portion 91 through the connecting portion 91 .

[0074] In this case, in some embodiments, during the formation of the sealing portion 81, an additional plug may be provided in the groove 42 in the reaction zone 32 at the connecting portion 91 to block the connecting portion 91, thereby forming a closed injection cavity 200 together with the mold 100 and the groove 42 located outside the reaction zone 32. In other embodiments, the flexible portion 120 of the mold 100 may be formed with an additional section to block the connecting portion 91 when the mold 100 is provided on the monopolar plate 1 during the formation of the sealing portion 81, thereby forming a closed injection cavity 200 together with the groove 42 located outside the reaction zone 32.

[0075] Please return to see FIG. 3B to FIG. 3E A mold 100' having a similar configuration to the mold 100 can be used to form a sealing portion 81' similar to the sealing portion 81 on another monopolar plate 1'. FIG. 3B to FIG. 3E As shown, the mold 100' may have a structure symmetrical to the mold 100. Accordingly, the sealing portion 81' formed by the mold 100' may have a structure symmetrical to the sealing portion 81. FIG. 3A to FIG. 3E The structure of the mold 100 ′ that is symmetrical to the mold 100 and the parts of the sealing portion 81 ′ that are similar to the sealing portion 81 are indicated by reference numeral “XX′” and are not described in detail herein.

[0076] like Figure 3CAs shown, the mold 100 is arranged on the first side 11 of the monopolar plate 1 in the aforementioned manner, and the mold 100' is arranged on the first side 11' of the monopolar plate 1' in a similar manner. The rigid portion 110 of the mold 100 is pressed against the bottom wall 42a of the groove 42 of the monopolar plate 1, and the rigid portion 110' of the mold 100' is pressed against the bottom wall 42a' of the groove 42' of the monopolar plate 1'. As described above, the ridge 61 on the second side 12 of the monopolar plate 1 and the ridge 61' on the second side 12' of the monopolar plate 1' can be aligned with each other and fixed relative to each other by a process such as welding or bonding. The rigid portion 110 of the mold 100 and the rigid portion 110' of the mold 100' are able to reliably clamp the bipolar plate 10 on both sides of the bipolar plate 10 composed of the monopolar plate 1 and the monopolar plate 1'. In addition, the flexible portion 120 of the mold 100 is pressed against the top wall 41a of the ridge 41 of the monopolar plate 1, and the flexible portion 120' of the mold 100' is pressed against the top wall 41a' of the ridge 41' of the monopolar plate 1'. In this way, the bottom wall 42a of the groove 42, the side wall 43 shared by the groove 42 and the ridge 41, the rigid portion 110 and the flexible portion 120 can enclose the injection cavity 200, and the bottom wall 42a' of the groove 42', the side wall 43' shared by the groove 42' and the ridge 41', the rigid portion 110' and the flexible portion 120' can enclose the injection cavity 200'. Due to the above configuration of the mold 100 and the mold 100', it is not necessary to apply a large pressing force to the flexible portion 120 and the flexible portion 120'. In some embodiments, it is even not necessary to apply a pressing force to the flexible portion 120 and the flexible portion 120'. Instead, the glue injection cavity 200 and the glue injection cavity 200' can be enclosed on the monopolar plate 1 and the monopolar plate 1' by relying only on the elasticity of the flexible portion 120 and the flexible portion 120'. This can prevent the ridges 41 and 41' of the monopolar plate 1 and the monopolar plate 1' from being subjected to excessive pressure and collapsing and deforming.

[0077] Figure 3D It is also shown that the liquid sealant 80' is injected into the injection cavity 200' through the injection hole 130' of the mold 100', and Figure 3E It is also shown that the liquid sealant 80' is cured to form a sealing portion 81', and the mold 100' is removed from the monopolar plate 1. FIG. 3B to FIG. 3E As shown, the method for forming a sealing portion on a monopolar plate 1' according to the present application may include: providing a mold 100'; setting the mold 100' on the monopolar plate 1' to enclose a glue injection cavity 200' with the monopolar plate 1'; injecting a sealant 80' into the glue injection cavity 200'; and curing the sealant 80' to form a sealing portion 81', and removing the mold 100'.

[0078] Figure 3EThe partial cross-section schematically shows that the bipolar plate 10 composed of the monopolar plate 1 and the monopolar plate 1' has a sealing portion 81 and a sealing portion 81' formed on opposite sides respectively. Figure 4 , which schematically shows in partial cross-section two bipolar plates 10 stacked on top of each other and the MEA 200 sandwiched between the two bipolar plates 10 when assembling a PEMFC stack. Figure 4 As shown, when squeezed by the adjacent bipolar plates 10 and MEA 200 , the sealing portion 81 can form a reliable seal that fits tightly against the side wall 43 , and the sealing portion 81 ′ can form a reliable seal that fits tightly against the side wall 43 ′, thereby improving the reliability of the PEMFC stack.

[0079] Although it is described above that the mold 100 and the mold 100' are used together as a kit, it should be understood that the mold 100 and the mold 100' can be used separately to form a seal on the monopolar plate 1, the monopolar plate 1' or the bipolar plate 10. For example, the mold 100' can be replaced by a support member, and the support member cooperates with the mold 100 on the opposite side to provide support, thereby forming a seal on one side of the bipolar plate 10. It should also be understood that the mold 100 and / or the mold 100' can form a seal at any suitable position on the flow field plate (monopolar plate 1, monopolar plate 1' or bipolar plate 10), and is not limited to the communication portion 91 described above.

[0080] It should also be understood that mold 100 and / or mold 100' can be part of a glue injection mold (mold) and, for example, arranged on a flow field plate together with the rest of a glue injection device to form a seal on the flow field plate through a single or multiple glue injection process.

[0081] It should also be understood that the methods and molds according to the present application may also be used to form seals on flow field plates of any other suitable electrochemical cells.

[0082] It should also be understood that, although the above description is that the sealant is injected into the injection cavity via the injection hole of the mold, the present application is not limited thereto. For example, the end of the mold according to the present application may be open, and cooperate with other rigid molds or flexible molds, and the sealant may be injected into the injection cavity via other rigid molds or flexible molds. For another example, the mold according to the present application may be part of a large mold, and the sealant may be injected into the injection cavity via the injection hole located on other parts of the large mold.

[0083] It should be understood that the terms "first", "second", "third", "fourth" and "fifth" are only used to distinguish one element, component or section from another element, component or section, but these elements, components and sections should not be limited by such terms.

[0084] The present application has been described in detail above in conjunction with specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and do not constitute a limitation to the present application. For those skilled in the art, various modifications or changes can be made to the present application without departing from the spirit of the present application, and these modifications or changes do not depart from the scope of the present application.

Claims

1. A method for forming a seal on a flow field plate of an electrochemical cell, the flow field plate comprising alternating ridges and grooves, each ridge comprising a top wall and each groove comprising a bottom wall, and adjacent ridges and grooves on the same side of the flow field plate share a side wall such that the side wall connects the top wall of the ridge and the bottom wall of the groove, the method comprising: Providing a mold, the mold comprising a rigid portion and a flexible portion connected to the rigid portion; The mold is arranged on the flow field plate in such a manner that the rigid portion is pressed against the bottom wall of the groove, and the flexible portion is pressed against at least the top wall of the ridge adjacent to the groove, so that the bottom wall of the groove, the side wall shared by the groove and the ridge, the rigid portion and the flexible portion enclose a glue injection cavity; Injecting sealant into the sealant injection cavity; as well as The sealant is cured to form a seal, and the mold is removed.

2. The method according to claim 1, characterized in that: The flow field plate comprises a first side and a second side opposite each other in a first thickness direction, the bottom wall and the top wall being spaced apart from each other by a first distance in the first thickness direction; The mold defines a second thickness direction, the rigid portion includes a first surface configured for engagement with the bottom wall, and the flexible portion includes a second surface configured for engagement with the top wall; When the mold is not disposed on the flow field plate, the second surface is retracted relative to the first surface by a second distance in the second thickness direction, and the second distance is smaller than the first distance; as well as When the mold is arranged on the flow field plate in the manner described, the second thickness direction coincides with the first thickness direction, the first surface is engaged with the bottom wall, and the second surface is engaged with the top wall, so that the flexible portion is elastically deformed, and the second surface is retracted by a third distance relative to the first surface in the second thickness direction, and the third distance is equal to the first distance.

3. The method according to claim 2, characterized in that: The rigid portion includes a first rigid section and a second rigid section extending from the first rigid section toward the flexible portion, the first rigid section including the first surface; The second rigid section includes a third surface that is indented relative to the first surface in the second thickness direction, and when the mold is arranged on the flow field plate in the manner described, the second rigid section extends above the bottom wall, and the third surface and the bottom wall are opposite to each other and spaced apart from each other in the first thickness direction; The second rigid section further comprises a groove recessed from the third surface into the second rigid section along the second thickness direction, the groove being configured to extend along the same extension direction as the groove, the bottom of the groove being spaced apart from the first surface by a fourth distance in the second thickness direction, the fourth distance being greater than the first distance; as well as Injecting the sealant into the injection cavity includes allowing the sealant to fill the groove.

4. The method according to claim 3, characterized in that: The cross section of the groove perpendicular to the extension direction is tapered, preferably a semicircle, an isosceles triangle or an isosceles trapezoid; and / or The third surface is retracted relative to the first surface by a fifth distance in the second thickness direction, the fifth distance being equal to the first distance; and / or The bottom wall is flat and perpendicular to the first thickness direction, and the first surface is flat and perpendicular to the second thickness direction.

5. The method according to any one of claims 2 to 4, characterized in that: The mould is an annular piece connected end to end and the flexible portion is pressed only against the top wall of the ridge; or The mold includes a first end and a second end opposite to each other, the flexible part includes a first flexible segment and a second flexible segment extending between the first end and the second end respectively, the first flexible segment includes the second surface, and the second flexible segment extends from the first flexible segment toward the rigid part, the second flexible segment includes a fourth surface indented relative to the first surface in the second thickness direction, the flexible part also includes a third flexible segment extending beyond the fourth surface along the second thickness direction at at least one of the first end and the second end, when the mold is arranged on the flow field plate in the manner described, the second flexible segment extends above the side wall and the bottom wall, the fourth surface is opposite to and spaced apart from the side wall and the bottom wall in the first thickness direction, and the third flexible segment is at least pressed against the side wall, preferably against the side wall and the bottom wall.

6. The method according to any one of claims 2 to 4, characterized in that: The flow field plate includes ridges and grooves on both the first side and the second side, the ridges and grooves being formed in such a manner that the same plate segment of the flow field plate defines one of the grooves and ridges on the first side and defines the other of the grooves and ridges on the second side, and for the grooves and ridges defined by the same plate segment, the bottom wall of the groove is common to the top wall of the ridge, and the side wall of the groove is common to the side wall of the ridge; The flow field plate includes a first groove, a second groove, and a third ridge between the first groove and the second groove on the first side, and a first ridge, a second ridge, and a third groove on the second side corresponding to the first groove, the second groove, and the third ridge, respectively; A portion of the third ridge is interrupted to form a connecting portion connecting the first groove and the second groove on the first side, and a blocking portion blocking the third groove on the second side; as well as The method includes forming a sealing portion at the connecting portion in the second groove through the mold to block the connection between the first groove and the second groove via the connecting portion. Preferably, the first groove is located in a reaction zone of the flow field plate for circulating a reaction fluid, and the second groove is located outside the reaction zone.

7. A mold for forming a seal on a flow field plate of an electrochemical cell, the flow field plate comprising alternating ridges and grooves, each ridge comprising a top wall and each groove comprising a bottom wall, and adjacent ridges and grooves on the same side of the flow field plate share a side wall such that the side wall connects the top wall of the ridge and the bottom wall of the groove, the mold comprising: Rigid part; as well as a flexible portion connected to the rigid portion; The mold is configured to be arranged on the flow field plate in such a manner that the rigid part is pressed against the bottom wall of the groove, and the flexible part is pressed against at least the top wall of the ridge adjacent to the groove, so that the bottom wall of the groove, the side wall shared by the groove and the ridge, the rigid part and the flexible part enclose a glue injection cavity.

8. The mold according to claim 7, characterized in that: The flow field plate comprises a first side and a second side opposite each other in a first thickness direction, the bottom wall and the top wall being spaced apart from each other by a first distance in the first thickness direction; The mold defines a second thickness direction, the rigid portion includes a first surface configured for engagement with the bottom wall, and the flexible portion includes a second surface configured for engagement with the top wall; When the mold is not disposed on the flow field plate, the second surface is retracted relative to the first surface by a second distance in the second thickness direction, and the second distance is smaller than the first distance; as well as When the mold is arranged on the flow field plate in the manner described, the second thickness direction coincides with the first thickness direction, the first surface is engaged with the bottom wall, and the second surface is engaged with the top wall, so that the flexible portion is elastically deformed, and the second surface is retracted by a third distance relative to the first surface in the second thickness direction, and the third distance is equal to the first distance.

9. The mold according to claim 8, characterized in that: The rigid portion includes a first rigid section and a second rigid section extending from the first rigid section toward the flexible portion, the first rigid section including the first surface; The second rigid section includes a third surface that is indented relative to the first surface in the second thickness direction, and when the mold is arranged on the flow field plate in the manner described, the second rigid section extends above the bottom wall, and the third surface and the bottom wall are opposite to each other and spaced apart from each other in the first thickness direction; as well as The second rigid section also includes a groove recessed into the second rigid section from the third surface along the second thickness direction, the groove being configured to extend along the same extension direction as the groove, the bottom of the groove being spaced apart from the first surface by a fourth distance in the second thickness direction, the fourth distance being greater than the first distance.

10. The mold according to claim 9, characterized in that: The cross section of the groove perpendicular to the extension direction is tapered, preferably a semicircle, an isosceles triangle or an isosceles trapezoid; and / or The third surface is retracted relative to the first surface by a fifth distance in the second thickness direction, the fifth distance being equal to the first distance; and / or The bottom wall is flat and perpendicular to the first thickness direction, and the first surface is flat and perpendicular to the second thickness direction.

11. The mold according to any one of claims 8 to 10, characterized in that: The mould is an annular piece connected end to end and the flexible portion is pressed only against the top wall of the ridge; or The mold includes a first end and a second end opposite to each other, the flexible part includes a first flexible segment and a second flexible segment extending between the first end and the second end respectively, the first flexible segment includes the second surface, and the second flexible segment extends from the first flexible segment toward the rigid part, the second flexible segment includes a fourth surface indented relative to the first surface in the second thickness direction, the flexible part also includes a third flexible segment extending beyond the fourth surface along the second thickness direction at at least one of the first end and the second end, when the mold is arranged on the flow field plate in the manner described, the second flexible segment extends above the side wall and the bottom wall, the fourth surface is opposite to and spaced apart from the side wall and the bottom wall in the first thickness direction, and the third flexible segment is at least pressed against the side wall, preferably against the side wall and the bottom wall.

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