Bipolar plate and manufacturing method thereof

Abstract

The invention discloses a bipolar plate and a manufacturing method thereof, and relates to a bipolar plate applied to a fuel cell, the bipolar plate comprises a metal substrate and two silica gel sealing layers; the metal substrate is provided with a first surface and a second surface, and at least one channel is arranged on the metal substrate. The two silica gel sealing layers are directly formed on the first surface and the second surface respectively in a one-time injection molding mode, and at least one connecting block is formed on one side of each silica gel sealing layer, so that automatic production is realized, and the production cost of the bipolar plate is reduced.

Description

Technical Field

[0001] The present invention relates to a bipolar plate used in a fuel cell and a manufacturing method of the bipolar plate, and in particular to a bipolar plate and a manufacturing method thereof. Background Art

[0002] Bipolar plate (BPP) is one of the core parts of fuel cells. It is a plate-like component sandwiched between individual cells. It can be used to isolate fuel gas and air, collect electrons, transfer heat, etc. It can also be used to seal the battery. The flow channel formed inside it has the function of transporting hydrogen and air.

[0003] When the bipolar plate is sandwiched between the units, in order to achieve a sealing effect, a sealing ring needs to be provided on both sides of the bipolar plate to achieve the sealing effect of the bipolar plate.

[0004] The existing sealing ring is partly pasted, and the other part is formed by forming the sealing rings on the anode plate and the cathode plate of the bipolar plate respectively by injection molding, and then welding the anode plate and the cathode plate.

[0005] The above-mentioned adhesive method requires a groove to be pre-set on the bipolar plate for the seal ring to be positioned and attached. The individual injection molding method cannot perform secondary injection, resulting in an increase in production costs and cannot achieve the effect of automated production.

[0006] In view of this, providing a bipolar plate that can achieve automated production and reduce production costs is the problem to be solved by the present invention. Summary of the invention

[0007] The main purpose of the present invention is to provide a bipolar plate and a method for manufacturing the same, in particular, a bipolar plate used in a fuel cell, and to form a silicone sealing layer on both surfaces of a metal substrate by a one-time injection molding method, thereby achieving the purpose of automated production and saving production costs.

[0008] In order to achieve the above-mentioned purpose, the present invention first provides a method for manufacturing a bipolar plate, comprising the following steps: providing a metal substrate, providing a mold and an injection molding step. The metal substrate has a first surface and a second surface. The mold is composed of at least one upper mold base and a lower mold base, and the metal substrate is placed between the upper mold base and the lower mold base to form a first molding space located on the first surface and a second molding space located on the second surface between the upper mold base and the lower mold base through the metal substrate, and the mold has at least one flow channel, the flow channel has a first feed channel connected to the first molding space and a second feed channel connected to the second molding space, and the first feed channel and the second feed channel are respectively in a corresponding arc shape. The injection molding step refers to injecting a liquid silicone into the mold through the flow channel, so that the liquid silicone is injected into the first molding space and the second molding space through the first feed channel and the second feed channel at the same time. After the liquid silicone is cooled, it forms a silicone sealing layer on the first surface and the second surface of the metal substrate at the same time to form a bipolar plate.

[0009] In one embodiment, the cross-sections of the first feed channel and the second feed channel are approximately in a corresponding C-shape.

[0010] In one embodiment, a pouring port and a plurality of flow channels are further provided in the mold, the flow channels surround the periphery of the metal substrate and are simultaneously connected to the pouring port, and each of the flow channels is connected to the first molding space through a first feed channel and is connected to the second molding space through a second feed channel.

[0011] In one embodiment, the silicone sealing layers on the first surface and the second surface are respectively formed into a ring shape and surround the periphery of the first surface and the second surface.

[0012] In one embodiment, a first feeding area is formed between the first molding space and the first feeding channel, and a second feeding area is formed between the second molding space and the second feeding channel.

[0013] In one embodiment, the height of the first molding space is higher than the height of the first feeding zone.

[0014] In one embodiment, the height of the second molding space is higher than the height of the second feeding zone.

[0015] To achieve the above-mentioned purpose, the present invention further provides a bipolar plate, which comprises: a metal substrate and two silicone sealing layers. The metal substrate is provided with a plurality of channels, and the metal substrate has a first surface and a second surface. The two silicone sealing layers are directly formed on the first surface and the second surface by injection molding, and surround the periphery of the first surface and the second surface, and surround the channel at the same time, and at least one connecting block is formed on one side of each silicone sealing layer.

[0016] In one embodiment, the height of each of the silicone sealing layers is greater than the height of the connecting block.

[0017] In one embodiment, the metal substrate is made of stainless steel.

[0018] Compared with the prior art, the present invention has the following advantages: the present invention can simultaneously perform the injection molding steps on the first surface and the second surface of the metal substrate. In addition to being able to form a more complete silicone sealing layer on the first surface and the second surface respectively, it can also realize the automated production of bipolar plates and effectively reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a top view of the bipolar plate in the present invention.

[0020] Figure 2 It is a cross-sectional schematic diagram of the bipolar plate in the present invention.

[0021] Figure 3 for Figure 2 A partially enlarged schematic diagram of .

[0022] Figure 4 It is a top view of the metal substrate in the present invention.

[0023] Figure 5 It is a cross-sectional view of the mold in the present invention.

[0024] Figure 6 for Figure 5 A partially enlarged schematic diagram of the .

[0025] In the above drawings, the meanings of the reference numerals are as follows:

[0026] 10: Bipolar plate;

[0027] 20: Metal substrate;

[0028] 21: channel;

[0029] 22: first surface;

[0030] 23: second surface;

[0031] 30: Silicone sealing layer;

[0032] 31: connection block;

[0033] 40: Mould;

[0034] 401: injection port;

[0035] 402: flow channel;

[0036] 403: first feed channel;

[0037] 404: first feeding zone;

[0038] 405: second feed channel;

[0039] 406: second feeding zone;

[0040] 41: upper die seat;

[0041] 42: lower die seat;

[0042] 43: first molding space;

[0043] 44: The second molding space. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to further understand the techniques, means and effects adopted by the present invention to achieve the predetermined objectives, preferred feasible embodiments are now cited and described in detail with reference to the accompanying drawings. It is believed that the objectives, features and advantages of the present invention should be able to provide a deep and specific understanding thereof.

[0045] like Figures 1 to 6 As shown, the present invention first provides a bipolar plate. The bipolar plate 10 is composed of a metal substrate 20 and two silicone sealing layers 30 .

[0046] The metal substrate 20 is composed of an anode plate and a cathode plate made of stainless steel, and has at least one channel 21 therein. The metal substrate 20 has a first surface 22 and a second surface 23 opposite to the first surface 22 .

[0047] The two silicone sealing layers 30 are directly formed on the first surface 22 and the second surface 23 by injection molding, and a height is formed on the first surface 22 and the second surface 23. At the same time, each silicone sealing layer 30 surrounds the periphery of the first surface 22 and the second surface 23 and surrounds the channel 21, so that the silicone sealing layers 30 are in a ring shape. At least one connecting block 31 is formed on one side of each silicone sealing layer 30 on the first surface 22 and the second surface 23, and the height of each silicone sealing layer 30 is higher than the height of each connecting block 31.

[0048] As described above, in order to enable the two silicone sealing layers 30 to be directly formed on the first surface 22 and the second surface 23 by injection molding, the present invention further provides a method for manufacturing a bipolar plate, which comprises the following steps: providing the metal substrate 20, providing a mold 40, and an injection molding step.

[0049] The mold 40 is composed of at least an upper mold base 41 and a lower mold base 42, so that the metal substrate 20 can be placed between the upper mold base 41 and the lower mold base 42, and a first molding space 43 located on the first surface 22 and a second molding space 44 located on the second surface 23 are formed by the metal substrate 20, the upper mold base 41 and the lower mold base 42, and the first molding space 43 and the second molding space 44 are not connected to each other.

[0050] In addition, the mold 40 also has at least one pouring port 401 for liquid silicone injection, and at least one flow channel 402 connected to the pouring port 401. The flow channel 402 is connected to the first molding space 43 and the second molding space 44, respectively, and there is a first feed channel 403 and a first feed area 404 between the flow channel 402 and the first molding space 43. The first feed channel 403 is approximately in an arc shape, and the first feed area 404 is also formed on the first surface 22 and is connected to the first molding space 43, and the height of the first molding space 43 is higher than the height of the first feed area 404. A second feed channel 405 and a second feed area 406 are provided between the flow channel 402 and the second molding space 44. The second feed channel 405 is approximately arc-shaped corresponding to the first feed channel 403, so that the cross-section of the first feed channel 403 and the second feed channel 405 is approximately C-shaped. The second feed area 306 is also formed on the second surface 23 and is interconnected with the second molding space 44, and the height of the second molding space 44 is higher than the height of the second feed area 406.

[0051] The injection molding step refers to injecting the above-mentioned liquid silicone into the mold 40 through the injection port 401, and allowing the liquid silicone to pass through the flow channel 402, and then pass through the first feed channel 403, the second feed channel 405, the first feed area 404 and the second feed area 406 in sequence, and finally injected into the first molding space 43 and the second molding space 44. After the liquid silicone is cooled inside the first molding space 43 and the second molding space 44, the silicone sealing layer 40 can be formed on the first surface 22 and the second surface 23 of the metal substrate 20 at the same time, thereby forming the bipolar plate 10.

[0052] In addition, after the liquid silicone in the first feeding area 404 and the second feeding area 406 is cooled, the connecting blocks 31 which are respectively connected to the silicone sealing layer 30 are formed on the first surface 12 and the second surface 13, and the height of the silicone sealing layer 30 is higher than the height of the connecting blocks 31.

[0053] It is worth mentioning that, since the metal substrate 10 in the present invention is approximately rectangular, in order to improve the integrity of the silicone sealing layer 30 after the injection molding step, a plurality of flow channels 402 are formed in the mold 40 in the present invention, and the flow channels 402 are respectively connected to the injection port 401 and surround the periphery of the metal substrate 20, and each of the flow channels 402 is respectively connected to the first molding space 43 through a first feed channel 403 and a first feed area 404, and is connected to the second molding space 44 through a second feed channel 405 and a second feed area 406, so that the bipolar plate 10 after molding has a plurality of the connection blocks 31 respectively connected to the silicone sealing layer 30 on the first surface 22 and the second surface 23.

[0054] As shown in the figure, two connecting blocks 31 are formed in each of the two long sides of the bipolar plate 10, and one connecting block 31 is formed in each of the two short sides. In other words, in the present invention, six groups of corresponding connecting blocks 31 are formed on the first surface 22 and the second surface 23, respectively, so that six flow channels 402, six first feed channels 403, six second feed channels 405, six first feed areas 404 and six second feed areas 406 that are interconnected with the injection port 401 are formed in the mold 40, and the six first feed areas 406 are connected to the first molding space 43, and the six second feed areas 404 are connected to the second molding space 44, thereby effectively ensuring the integrity of the silicone sealing layer 20 after injection molding, and avoiding the problem of material shortage or incomplete injection.

[0055] Therefore, the number of the connection blocks 31 can be changed with the size of the bipolar plate 10 , and the number of the flow channels 402 in the mold 40 can also be increased or decreased with the number of the connection blocks 31 .

[0056] Furthermore, in the present invention, since the first feed channel 403 and the second feed channel 405 are approximately C-shaped, and the first feed channel 403 and the second feed channel 405 are respectively connected to the first feed area 404 and the second feed area 405, therefore, after the liquid silicone is cooled and solidified in the mold 40, the bipolar plate 10 can be removed from the mold 40 by simply cutting off the connection between the first feed channel 403 and the first feed area 404 and the connection between the first feed channel 405 and the second feed area 406. Moreover, since the heights of the first molding space 43 and the second molding space 44 are both greater than the first feed area 404 and the second feed area 406, the integrity of the silicone sealing layer 30 can be effectively maintained, thereby enabling the bipolar plate 10 to achieve the effect of automated production and effectively reducing production costs.

[0057] The above is a detailed description and drawings of the preferred embodiments of the present invention, which are not intended to limit the present invention. The entire scope of the present invention shall be based on the above claims. All embodiments and similar structures of the spirit of the patent scope and similar variations thereof shall be included in the present invention.

Claims

1. A method for manufacturing a bipolar plate, comprising the following steps: Providing a metal substrate having a first surface and a second surface; and A mold is provided, which is composed of at least an upper mold base and a lower mold base, and the metal substrate is placed between the upper mold base and the lower mold base, so that a first molding space located on the first surface and a second molding space located on the second surface are formed between the upper mold base and the lower mold base through the metal substrate, and the mold has at least one flow channel, the flow channel has a first feed channel connected to the first molding space and a second feed channel connected to the second molding space, and the first feed channel and the second feed channel are respectively in a corresponding arc shape; and An injection molding step is performed to inject a liquid silicone into the mold through the flow channel, so that the liquid silicone is injected into the first molding space and the second molding space through the first feed channel and the second feed channel at the same time. After the liquid silicone is cooled, a silicone sealing layer is formed on the first surface and the second surface of the metal substrate at the same time to form a bipolar plate.

2. The method for manufacturing a bipolar plate according to claim 1, characterized in that: The cross sections of the first feed channel and the second feed channel are in a corresponding C-shape.

3. The method for manufacturing a bipolar plate according to claim 1, characterized in that: The mold is also provided with a pouring port and a plurality of flow channels, which surround the periphery of the metal substrate and are simultaneously connected to the pouring port, and each of the flow channels is connected to the first molding space through a first feed channel and to the second molding space through a second feed channel.

4. The method for manufacturing a bipolar plate according to claim 1, characterized in that: The silicone sealing layers on the first surface and the second surface respectively form a ring shape and surround along the periphery of the first surface and the second surface.

5. The method for manufacturing a bipolar plate according to claim 1, characterized in that: A first feeding area is formed between the first molding space and the first feeding channel, and a second feeding area is formed between the second molding space and the second feeding channel.

6. The method for manufacturing a bipolar plate according to claim 5, characterized in that: The height of the first molding space is higher than the height of the first feeding zone.

7. The method for manufacturing a bipolar plate according to claim 5, characterized in that: The height of the second molding space is higher than the height of the second feeding zone.

8. A bipolar plate comprising: A metal substrate having a plurality of flow channels disposed therein and having a first surface and a second surface; and Two silicone sealing layers are directly formed on the first surface and the second surface by injection molding, and surround the periphery of the first surface and the second surface and the channel at the same time, and at least one connecting block is formed on one side of each silicone sealing layer.

9. The bipolar plate according to claim 8, characterized in that: The height of each of the silicone sealing layers is greater than the height of the connecting block.

10. The bipolar plate according to claim 9, characterized in that: The metal base plate is made of stainless steel.

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