Single cell of fuel cell, and fuel cell stack

Abstract

The present application relates to the technical field of fuel cells, and in particular relates to a single cell of a fuel cell, and a fuel cell stack. The single cell comprises a cathode unipolar plate, a membrane electrode and an anode unipolar plate, which are stacked, and first sealing members connecting the cathode unipolar plate, the membrane electrode and the anode unipolar plate, wherein each first sealing member comprises a hydrogen cavity sealing portion and an oxygen cavity sealing portion; the hydrogen cavity sealing portions can seal hydrogen cavity openings; and the oxygen cavity sealing portions can seal oxygen cavity openings. The single cell further comprises an oxygen cavity insert, wherein an oxygen cavity sealing member and a hydrogen cavity sealing member are provided on the cathode unipolar plate; a plurality of oxygen channels are present on the oxygen cavity insert; the cathode unipolar plate is provided with a plurality of oxygen through holes; the plurality of oxygen through holes are located between the oxygen cavity sealing member and the oxygen cavity sealing portion; and each oxygen channel is in communication with each oxygen through hole. The single cell further comprises a hydrogen cavity insert, wherein a plurality of hydrogen channels are present on the hydrogen cavity insert; the anode unipolar plate is provided with a plurality of hydrogen through holes; the plurality of hydrogen through holes are located between the hydrogen cavity sealing member and the hydrogen cavity sealing portion; and each hydrogen channel is in communication with each hydrogen through hole.

Description

Fuel cell and fuel cell stack Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a fuel cell single cell and a fuel cell stack. Background Art

[0002] An integrated fuel cell is assembled from individual cells, which are composed of a cathode unipolar plate, a membrane electrode assembly, and an anode unipolar plate, assembled in sequence to form a single cell. To isolate the reactants and products, the interfaces between the cathode unipolar plate and the membrane electrode assembly, the anode unipolar plate and the membrane electrode assembly, and the cathode and anode unipolar plates must be sealed. Furthermore, to facilitate the flow of reactants and products, the hydrogen chamber port and hydrogen field, the oxygen chamber port and oxygen field, and the water chamber port and cooling field all require flow channels.

[0003] In the current, common integrated fuel cell structure, sealing is achieved between the cathode unipolar plate and the membrane electrode assembly (MEA). The adhesive coats the entire plate periphery and the hydrogen-water cavity. The reactant, hydrogen, flows from the hydrogen cavity through the membrane electrode through-holes between the anode unipolar plate and the MEA. The anode unipolar plate and the MEA are similarly sealed with adhesive, coating the entire plate periphery and the oxygen-water cavity. The reactant, air (oxygen), flows from the oxygen cavity through the membrane electrode through-holes between the cathode unipolar plate and the MEA. On the cathode unipolar plate facing the water field, a seal is injection-molded along the entire plate periphery and the hydrogen-oxygen cavity. The water cavity inlet is spaced apart. Coolant flows from the water cavity through the seals at intervals between the cathode and Yang unipolar plates. The process requires two to three process steps and two to three different methods to seal these three interfaces, involving three to four different types of sealing interfaces. This exponentially increases the complexity and workload of the process, manufacturing, and research on interface failures.

[0004] Each of the three aforementioned interface types requires its own failure mode analysis and prediction, with diverging research directions and exponentially increasing workload. Regarding airtight reliability, the three aforementioned failure modes present a significant risk of seal failure, which can lead to safety issues related to burnout due to cross-flow, safety issues related to hydrogen leakage due to external leakage, and efficiency issues such as pressure drop due to gas leakage.

[0005] Summary of the Invention

[0006] The present application provides a fuel cell cell and a fuel cell stack, which are intended to directly connect the cathode monopolar plate, membrane electrode and anode monopolar plate through injection molding, and to allow the gas to cross over and enter the respective flow fields by opening a through hole on one side of the gas cavity of the plate.

[0007] The present application provides a fuel cell unit cell, the unit cell comprising a cathode monopolar plate, a membrane electrode, and an anode monopolar plate stacked in sequence, and a first sealing member connecting the cathode monopolar plate, the membrane electrode, and the anode monopolar plate;

[0008] The first sealing member includes a hydrogen cavity sealing portion and an oxygen cavity sealing portion, wherein the hydrogen cavity sealing portion is capable of sealing the hydrogen cavity openings between the cathode unipolar plate and the membrane electrode and between the membrane electrode and the anode unipolar plate, and the oxygen cavity sealing portion is capable of sealing the oxygen cavity openings between the cathode unipolar plate and the membrane electrode and between the membrane electrode and the anode unipolar plate;

[0009] The single cell further includes an oxygen cavity insert, an oxygen cavity seal and a hydrogen cavity seal are provided on the cathode monopolar plate, the oxygen cavity seal and the hydrogen cavity seal are located on the side of the cathode monopolar plate away from the membrane electrode, and the oxygen cavity seal is arranged around the oxygen cavity opening of the cathode monopolar plate, and is located between the edge of the cathode monopolar plate and the oxygen cavity seal portion, and the hydrogen cavity seal is arranged around the hydrogen cavity opening of the cathode monopolar plate, and is located between the edge of the cathode monopolar plate and the hydrogen cavity seal portion;

[0010] The oxygen chamber insert is located on the side of the cathode monopolar plate facing the membrane electrode, and a plurality of oxygen channels are provided on the oxygen chamber insert. A plurality of oxygen through holes are provided on the side of the oxygen chamber opening of the cathode monopolar plate close to the flow field area. The plurality of oxygen through holes are located between the oxygen chamber seal and the oxygen chamber sealing portion, and each of the oxygen channels is connected to each of the oxygen through holes.

[0011] The single cell also includes a hydrogen chamber insert, which is located on the side of the anode monopolar plate close to the membrane electrode. There are multiple hydrogen channels on the hydrogen chamber insert. A plurality of hydrogen through holes are provided on the side of the hydrogen chamber opening of the anode monopolar plate close to the flow field area. The plurality of hydrogen through holes are located between the hydrogen chamber seal and the hydrogen chamber sealing portion, and each of the hydrogen channels is connected to each of the hydrogen through holes.

[0012] In one possible design, the first sealing member further includes a water cavity sealing portion, which is capable of sealing the water cavity openings between the cathode monopolar plate and the membrane electrode and between the membrane electrode and the anode monopolar plate;

[0013] The water cavity sealing portion is also located at the water cavity opening on the side of the cathode monopolar plate away from the membrane electrode.

[0014] In one possible design, a cooling liquid channel is provided on the water cavity sealing portion located on the side of the cathode monopolar plate facing away from the membrane electrode;

[0015] The cooling channel is located on a side of the water cavity sealing portion close to the flow field area.

[0016] In one possible design, the first seal also includes an edge sealing portion, which is arranged at the edge between the cathode monopolar plate and the membrane electrode, the edge between the membrane electrode and the anode monopolar plate, and the edge of the cathode monopolar plate away from the membrane electrode.

[0017] In one possible design, a first injection hole is provided at the outer edge and the cavity opening of the cathode monopolar plate, and a second injection hole is provided at the outer edge and the cavity opening of the membrane electrode, and the first injection hole and the second injection hole are arranged opposite to each other;

[0018] The hydrogen chamber sealing portion, the oxygen chamber sealing portion, the water chamber sealing portion and the edge sealing portion are arranged through the first injection hole and the second injection hole.

[0019] In one possible design, a first protrusion is provided at the outer edge and the cavity position of the cathode monopolar plate, the first protrusion accommodates the first seal between the cathode plate and the membrane electrode, and the first injection hole is provided in the first protrusion;

[0020] A second protrusion is provided at the outer edge and the cavity position of the anode monopolar plate, and the second protrusion accommodates the first sealing member between the membrane electrode and the anode monopolar plate.

[0021] In a possible design, a cooling liquid channel is provided on a side of the second protrusion located in the water cavity close to the flow field area.

[0022] In one possible design, the height of the oxygen chamber insert is the same as the height of the first protrusion, and the distance between the oxygen chamber insert and the first protrusion is at least 2 mm;

[0023] The height of the hydrogen chamber insert is the same as that of the second protrusion, and the distance between the hydrogen chamber insert and the second protrusion is at least 2 mm.

[0024] In a possible design, the height of the oxygen chamber sealing member after being compressed is equal to the height of the edge sealing portion located on the first protrusion after being compressed;

[0025] The height of the hydrogen chamber sealing member after being compressed is equal to the sum of the height of the first protrusion and the height of the edge sealing portion located on the first protrusion after being compressed.

[0026] In a possible design, the oxygen chamber seal includes a plurality of first support portions, and a first channel is formed between adjacent first support portions. The first channel can connect the oxygen chamber port of the cathode monopolar plate and the oxygen through hole.

[0027] In a possible design, the height of the first supporting portion is equal to the sum of the height of the first protruding portion and the height of the edge sealing portion located on the first protruding portion after being compressed.

[0028] In one possible design, the hydrogen chamber seal includes a plurality of second support portions, and second channels are formed between adjacent second support portions. The second channels can connect the hydrogen chamber opening of the cathode monopolar plate and the hydrogen through hole of the adjacent anode monopolar plate.

[0029] In a possible design, the height of the second supporting portion is equal to the sum of the height of the first protruding portion and the height of the edge sealing portion located on the first protruding portion after being compressed.

[0030] In one possible design, the distance between the oxygen chamber sealing member and the oxygen chamber sealing portion is 1 mm to 5 mm, and the distance between the oxygen chamber sealing member and the edge sealing portion is 1 mm to 5 mm;

[0031] The distance between the hydrogen chamber sealing member and the oxygen chamber sealing portion is 1 mm to 5 mm, and the distance between the hydrogen chamber sealing member and the edge sealing portion is 1 mm to 5 mm.

[0032] The present application also provides a fuel cell stack, comprising at least two stacked fuel cell cells, wherein the fuel cell cells are the fuel cell cells described above.

[0033] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a schematic structural diagram of a fuel cell in the prior art;

[0035] FIG2 is a schematic diagram of an explosion of a single fuel cell provided in this application;

[0036] FIG3 is a schematic structural diagram of the cathode monopolar plate provided in this application;

[0037] FIG4 is a schematic diagram of the structure of the membrane electrode provided in this application;

[0038] FIG5 is a schematic cross-sectional view of the cavity opening of a single fuel cell provided by the present application (this cross-sectional view is a combined cross-sectional view of a seal and a plate);

[0039] FIG6 is a schematic structural diagram of the water field side water cavity sealing portion provided by the present application;

[0040] FIG7 is a schematic structural diagram of the hydrogen chamber insert provided in this application;

[0041] FIG8 is a schematic structural diagram of the oxygen chamber insert provided in this application;

[0042] FIG9 is a schematic diagram of a hydrogen chamber sealing portion, a hydrogen chamber sealing member, and a second supporting portion at the hydrogen chamber opening provided by the present application;

[0043] FIG10 is a schematic diagram of the oxygen chamber sealing portion, the oxygen chamber sealing member and the first supporting portion at the oxygen chamber port provided by the present application;

[0044] FIG11 is a cross-sectional schematic diagram of a single fuel cell at the hydrogen chamber port;

[0045] FIG12 is an enlarged schematic diagram of the hydrogen cavity port in FIG11 away from the flow field area;

[0046] FIG13 is an enlarged schematic diagram of the flow field area near the hydrogen cavity in FIG11;

[0047] FIG14 is an enlarged schematic diagram of the flow field area in FIG11 ;

[0048] FIG15 is a cross-sectional schematic diagram of the oxygen chamber port of a single fuel cell;

[0049] FIG16 is an enlarged schematic diagram of the oxygen chamber port in FIG15 away from the flow field area;

[0050] FIG17 is an enlarged schematic diagram of the flow field area near the oxygen chamber port in FIG15;

[0051] FIG18 is an enlarged schematic diagram of the flow field area in FIG15 ;

[0052] FIG19 is a cross-sectional schematic diagram of the water cavity port of a single fuel cell;

[0053] FIG20 is an enlarged schematic diagram of the edge sealing portion in FIG19;

[0054] FIG21 is an enlarged schematic diagram of the seals on both sides of the water cavity opening in FIG19;

[0055] FIG22 is an enlarged schematic diagram of the flow field area in FIG19 ;

[0056] FIG23 is a schematic structural diagram of a fuel cell provided in this application in another specific embodiment;

[0057] FIG24 is a schematic diagram of the water cavity opening of the anode monopolar plate in FIG23;

[0058] FIG25 is a schematic cross-sectional view of the water cavity port of the fuel cell cell in FIG24 .

[0059] Reference numerals: 1′-cathode monopolar plate; 2′-membrane electrode; 3′-anode monopolar plate; 4′-adhesive; 5′-seal; 1-cathode monopolar plate; 11-oxygen chamber insert; 111-oxygen channel; 12-oxygen chamber seal; 121-first support portion; 121a-first channel; 13-hydrogen chamber seal; 131-second support portion; 131a-second channel; 14-oxygen through-hole; 15-first injection hole; 16-first protrusion;

[0060] 2-membrane electrode; 21-second injection hole; 22-membrane electrode cathode side flow field area; 23-membrane electrode anode side flow field area; 3-anode monopolar plate; 31-hydrogen chamber insert; 311-hydrogen channel; 32-hydrogen through hole; 33-second protrusion; 4-first seal; 41-hydrogen chamber sealing part; 42-oxygen chamber sealing part; 43-water chamber sealing part; 431-coolant channel; 44-edge sealing part.

[0061] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0062] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0063] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0064] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0065] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0066] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that an element is connected to another element "on" or "under", it can not only be directly connected to the other element "on" or "under", but also be indirectly connected to the other element "on" or "under" through an intermediate element.

[0067] As shown in Figure 1, in the prior art, fuel cell sealing is achieved through a combination of two methods. The interfaces between the anode unipolar plate 3' and the membrane electrode 2', and between the cathode unipolar plate 1' and the membrane electrode 2', are sealed using adhesive 4', while the interface between the anode unipolar plate 3' and the cathode unipolar plate 1' is sealed using a sealant 5'. The bonding of the anode unipolar plate 3' and the membrane electrode 2' can be performed simultaneously with the bonding of the cathode unipolar plate 1' and the membrane electrode 2', or in separate steps using different adhesives 4'. The sealing of the cathode unipolar plate 1' and the anode unipolar plate 3' requires a process such as injection molding or compression molding. This process requires two to three steps and two to three different methods to seal these three interfaces. Three to four different types of sealing interfaces are involved (at least one adhesive interface, injection molding interface, and mechanical assembly interface). This exponentially increases the complexity and workload of the process, manufacturing process, and research on interface failures.

[0068] To this end, as shown in Figures 2 to 4, this embodiment provides a single fuel cell. The single cell includes a cathode monopolar plate 1, a membrane electrode 2, and an anode monopolar plate 3 stacked in sequence, and a first seal 4 connecting the cathode monopolar plate 1, the membrane electrode 2, and the anode monopolar plate 3. A first injection hole 15 is provided on the outer edge and cavity position of the cathode monopolar plate, and a second injection hole 21 is provided on the outer edge and cavity position of the membrane electrode 2. The first injection hole 15 and the second injection hole 21 are arranged opposite each other. Part of the first seal 4 is provided on the edge of the cathode plate away from the membrane electrode 2, and part of the first seal 4 passes through the first injection hole 15 and the second injection hole 21 to seal the outer edge and cavity position of the cathode monopolar plate 1, the membrane electrode 2, and the anode monopolar plate 3.

[0069] As shown in Figure 5, the first seal 4 includes a hydrogen chamber sealing portion 41, an oxygen chamber sealing portion 42, a water chamber sealing portion 43, and an edge sealing portion 44. The edge sealing portion 44 is provided at the edge between the cathode monopolar plate 1 and the membrane electrode 2, the edge between the membrane electrode 2 and the anode monopolar plate 3, and the edge of the cathode monopolar plate 1 facing away from the membrane electrode 2. The water chamber sealing portion can seal the water chamber openings between the cathode monopolar plate 1 and the membrane electrode 2, and between the membrane electrode 2 and the anode monopolar plate 3. The water chamber sealing portion 43 is also located at the water chamber opening on the side of the cathode monopolar plate 1 facing away from the membrane electrode 2. The hydrogen chamber sealing portion 41 can seal the hydrogen chamber openings between the cathode monopolar plate 1 and the membrane electrode 2, and between the membrane electrode 2 and the anode monopolar plate 3. The oxygen chamber sealing portion 42 can seal the oxygen chamber openings between the cathode monopolar plate 1 and the membrane electrode 2, and between the membrane electrode 2 and the anode monopolar plate 3.

[0070] As shown in Figures 7 to 10, the single cell further includes an oxygen chamber insert 11. An oxygen chamber seal 12 and a hydrogen chamber seal 13 are provided on the cathode monopolar plate 1. The oxygen chamber seal 12 and the hydrogen chamber seal 13 are located on the side of the cathode monopolar plate 1 facing away from the membrane electrode 2. The oxygen chamber seal 12 surrounds the oxygen chamber opening of the cathode monopolar plate 1 and is located between the edge seal 44 and the oxygen chamber seal 42. The hydrogen chamber seal 13 surrounds the hydrogen chamber opening of the cathode monopolar plate 1 and is located between the edge seal 44 and the hydrogen chamber seal 41. The oxygen chamber insert 11 is located on the side of the cathode monopolar plate 1 facing the membrane electrode 2. Multiple oxygen channels 111 are provided on the oxygen chamber insert 11. Multiple oxygen through-holes 14 are provided on the side of the oxygen chamber opening of the cathode monopolar plate 1 near the flow field. The multiple oxygen through-holes 14 are located between the oxygen chamber seal 12 and the oxygen chamber seal 42. Each oxygen channel 111 communicates with a respective oxygen through-hole 14. The single cell also includes a hydrogen chamber insert 31, which is located on the side of the anode monopolar plate 3 facing the membrane electrode 2. There are multiple hydrogen channels 311 on the hydrogen chamber insert 31, and multiple hydrogen through holes 32 are provided on the side of the hydrogen chamber opening of the anode monopolar plate 3 close to the flow field area. The multiple hydrogen through holes 32 are located between the hydrogen chamber seal 13 and the hydrogen chamber sealing portion 41, and each hydrogen channel 311 is connected to each hydrogen through hole 32.

[0071] In this embodiment, holes are opened on the frames of the monopolar plates and the membrane electrode 2 so that the injection molding material can pass through the holes into the space between the cathode monopolar plate 1 and the membrane electrode 2 and between the membrane electrode 2 and the anode monopolar plate 3 to connect the three components together. Specifically, before the cathode monopolar plate 1, the membrane electrode 2 and the anode monopolar plate 3 are injection molded and connected, the oxygen chamber insert 11, the oxygen chamber seal 12 and the hydrogen chamber seal 13 are injection molded on the cathode monopolar plate 1 together, and the hydrogen chamber insert 31 is injection molded on the anode monopolar plate 3. Then, the anode monopolar plate 3, the membrane electrode 2 and the cathode monopolar plate 1 are stacked in the mold in sequence. The injection molding material flows along the first injection molding hole 15 of the cathode monopolar plate 1 to the outer edge and cavity opening position between the cathode monopolar plate 1 and the membrane electrode 2. The injection molding material then flows along the second injection molding hole 21 of the membrane electrode 2 to the outer edge and cavity opening position between the membrane electrode 2 and the anode monopolar plate 3, forming a hydrogen sealing portion that seals the hydrogen cavity opening, an oxygen cavity sealing portion 42 that seals the oxygen cavity opening and an edge sealing portion, so that the injection molding material connects the cathode monopolar plate 1, the membrane electrode 2 and the anode monopolar plate 3 to achieve sealing of the hydrogen field and the oxygen field. At the same time, the side of the cathode monopolar plate 1 facing the water field is simultaneously injection molded to form a water cavity seal. In this embodiment, the oxygen in the oxygen field can cross over the oxygen cavity of the cathode monopolar plate 1, flow along the oxygen through-hole 14 to the oxygen channel 111, and then flow along the oxygen channel 111 to the flow field area of ​​the membrane electrode 2. At the same time, the oxygen cavity seal 12 and the oxygen cavity sealing portion 42 can prevent the leakage of oxygen. The hydrogen in the hydrogen field can cross over the hydrogen cavity of the anode monopolar plate 3, flow along the hydrogen through-hole 32 to the hydrogen channel 311, and then flow along the hydrogen channel 311 to the flow field area of ​​the membrane electrode 2. At the same time, after the single cells are stacked, the hydrogen cavity seal 13 and the hydrogen cavity sealing portion 41 can prevent the leakage of hydrogen. In this embodiment, the air cavity seal and the water cavity seal are only the injection molding interface produced by the injection molding process (when multiple single cells are stacked to form a battery stack, there are multiple mechanical stress interfaces generated when the batteries are assembled), which reduces the types of sealing failures and reduces the risks of external leakage and cross-leakage.

[0072] The first injection holes 15 have a length of 0.5-5 mm and a width of 0.5-5 mm, and the interval between adjacent first injection holes 15 is 2-200 mm. The second injection holes 21 have a length of 0.5-5 mm and a width of 0.5-5 mm, and the interval between adjacent second injection holes 2112 is 2-200 mm.

[0073] The width of each oxygen through hole 14 is 0.1 mm to 2 mm, the length is 0.5 mm to 4.5 mm, and the spacing is 0.1 mm to 2 mm. The width of each hydrogen through hole 32 is 0.1 mm to 2 mm, the length is 0.5 mm to 4.5 mm, and the spacing is 0.1 mm to 2 mm.

[0074] The oxygen chamber insert 11 and the hydrogen chamber insert 31 can be made of injection molding materials such as rubber, polysulfone, polyetherimide, or metal parts such as iron and titanium, and are fixed to the electrode plates by spot welding or gluing. Before spot welding the inserts, the oxygen chamber seal 12 and the hydrogen chamber seal 13 need to be injection molded on the cathode monopolar plate 1 in advance.

[0075] Furthermore, as shown in FIG6 , a cooling liquid channel 431 is provided on the side of the water cavity sealing portion 43 of the cathode monopolar plate 1 away from the membrane electrode 2 and close to the flow field area, so that the cooling liquid can flow along the cooling liquid channel 431 to the water field between the cathode monopolar plate 1 and the connected anode monopolar plate 3 for cooling.

[0076] As shown in Figure 2, a first protrusion 16 is provided on the outer edge and at the cavity opening of the cathode monopolar plate 1. The first protrusion 16 protrudes in a direction away from the membrane electrode 2. The groove formed by the first protrusion 16 accommodates the first seal 4 between the cathode plate and the membrane electrode 2. The first injection hole 15 is provided in the first protrusion 16. A second protrusion 33 is provided on the outer edge and at the cavity opening of the anode monopolar plate 3. The second protrusion 33 is recessed in a direction away from the membrane electrode 2. The groove formed by the second protrusion 33 accommodates the first seal 4 between the membrane electrode 2 and the anode monopolar plate 3.

[0077] In this embodiment, after the cathode monopolar plate 1, the membrane electrode 2 and the anode monopolar plate 3 are stacked, a receiving space is formed between the first protrusion 16 and the membrane electrode 2 and between the membrane electrode 2 and the second protrusion 33, so that the injection molding material can be confined within the receiving space, preventing the injection molding material from overflowing from the outer edges of the components and the cavity position.

[0078] The height of the first raised portion 16 is approximately the same as the height of the flow field region, and is compensated for by the thickness of the membrane electrode 2 frame and the flow field region. The overall height is between 0.15mm and 0.5mm. The raised surface is continuously closed at all locations, and the width is between 2mm and 8mm. The height of the second raised portion 33 is approximately the same as the height of the flow field region, and is compensated for by the thickness of the membrane electrode 2 frame and the flow field region. The overall height is between 0.15mm and 0.5mm. The raised surface is continuously closed at all locations, and the width is between 2mm and 8mm.

[0079] Furthermore, in order to enable the injection molding material to fill the space between the electrode plate and the frame of the membrane electrode 2, a material with a lower viscosity of the injection molding material can be selected. In this embodiment, one of liquid silicone rubber, EPDM rubber, and fluororubber can be used as the injection molding material. Taking silicone rubber as an example, in order to compensate for the insufficient self-adhesion of the liquid silicone rubber material, before injection molding, a layer of adhesive is pre-coated on all the electrode plates and the frame of the membrane electrode 2 that are in contact with the liquid silicone rubber, and an effective bonding interface between the liquid silicone rubber and the electrode plates and the frame of the membrane electrode 2 is formed during the injection molding fluidization process. The material of the adhesive can be one of the reactive adhesives such as silane coupling agent and Chemlock.

[0080] The adhesive coating areas of the edge seal are the cathode monopolar plate 1 facing the water field and the membrane electrode 2, the membrane electrode 2 facing the cathode monopolar plate 1 and the anode monopolar plate 3, and the anode monopolar plate 3 facing the membrane electrode 2. The adhesive coating areas of the oxygen chamber seal 42 and the hydrogen chamber seal 41 are the cathode monopolar plate 1 facing the membrane electrode 2, the membrane electrode 2 facing the cathode monopolar plate 1 and the anode monopolar plate 3, and the anode monopolar plate 3 facing the membrane electrode 2. The adhesive coating areas of the water chamber seal 43 are the cathode monopolar plate 1 facing the water field and the membrane electrode 2, the membrane electrode 2 facing the cathode monopolar plate 1 and the anode monopolar plate 3, and the anode monopolar plate 3 facing the membrane electrode 2.

[0081] Alternatively, the injection molding material may be a self-adhesive material, such as polyolefin, which can be directly injection molded.

[0082] To further prevent overflow of the injection molding material, a first clamping portion is provided on the outer edge and cavity of the cathode monopolar plate 1. The first clamping portion is located on either side of the first protrusion 16 and is in contact with the membrane electrode 2. A second clamping portion is also provided on the outer edge and part of the cavity of the cathode monopolar plate 1. The second clamping portion is located on either side of the second protrusion 33 and is in contact with the membrane electrode 2. In this embodiment, by leaving the first clamping portion on either side of the first protrusion 16 and the second clamping portion on either side of the second protrusion 33, the mold can compress the single cell through the first and second clamping portions, thus limiting the molding process of the injection molding material.

[0083] The width of the first clamping portion is 1 mm to 5 mm, and the width of the second clamping portion is 1 mm to 5 mm.

[0084] In some embodiments, the oxygen chamber insert 11 has the same height as the first raised portion 16 and a width of 2 mm to 8 mm. The oxygen channels 111 formed on the oxygen chamber insert 11 have a width of 0.1 mm to 2 mm, and the spacing between each oxygen channel 111 is 0.1 mm to 2 mm. The oxygen chamber insert 11 is at least 2 mm away from the first raised portion 16, facilitating visual inspection of the placement of the sealant during injection molding. The hydrogen chamber insert 31 has the same height as the second raised portion 33. The hydrogen channels 311 formed on the hydrogen chamber insert 31 have a width of 0.1 mm to 2 mm, and the spacing between each hydrogen channel 311 is 0.1 mm to 2 mm. The hydrogen chamber insert 31 is at least 2 mm away from the second raised portion 33, facilitating visual inspection of the placement of the sealant during injection molding.

[0085] The compressed height of the oxygen chamber seal 12 is equal to the compressed height of the edge seal on the first protrusion 16, ensuring sealing on the water field side after adjacent cells are stacked. The compressed height of the hydrogen chamber seal 13 is equal to the sum of the height of the first protrusion 16 and the compressed height of the edge seal on the first protrusion 16, ensuring sealing on the water field side after adjacent cells are stacked.

[0086] The width of the oxygen chamber seal is 2mm-8mm, the spacing between the oxygen chamber seal 12 and the oxygen chamber sealing portion 42 is 1mm-5mm, and the spacing between the oxygen chamber seal 12 and the edge sealing portion is 1mm-5mm. The width of the hydrogen chamber seal 13 is 2mm-8mm, the spacing between the hydrogen chamber seal 13 and the oxygen chamber sealing portion 42 is 1mm-5mm, and the spacing between the hydrogen chamber seal 13 and the edge sealing portion is 1mm-5mm.

[0087] As shown in Figures 9 and 10, the oxygen chamber seal 12 includes a plurality of first support portions 121, with first channels 121a formed between adjacent first support portions 121. The first channels 121a can connect the oxygen chamber opening of the cathode monopolar plate 1 and the oxygen through-hole 14, allowing the oxygen in the oxygen field to cross over the hydrogen chamber of the cathode monopolar plate 1 and flow along the first channels 121a, the oxygen through-hole 14, and the oxygen channel 111 to the flow field area. The height of the first support portion is equal to the sum of the height of the first protrusion 16 and the height of the compressed edge sealing portion located on the first protrusion 16, ensuring the sealing of the water field side after the adjacent single cells are stacked. The first support portion 121 can be extended during the injection molding of the oxygen chamber seal 12 and prepared using the same materials and processes as the oxygen seal, or it can be prepared as an insert separately and then prepared using the same materials and processes as the oxygen chamber insert 11.

[0088] As shown in Figures 9 and 10, the hydrogen chamber seal includes a plurality of second support portions 131, and a second channel 131a is formed between adjacent second support portions 131. The second channel 131a can connect the hydrogen chamber opening of the cathode monopolar plate 1 and the hydrogen through hole 32 of the adjacent anode monopolar plate 3, so that the hydrogen in the hydrogen field can cross over the hydrogen chamber of the anode monopolar plate 3 and flow along the second channel 131a, the hydrogen through hole 32 and the hydrogen channel 311 to the flow field area. The height of the second support portion is equal to the height of the first protrusion 16 and the height of the edge sealing portion located on the first protrusion 16 after being compressed, ensuring the sealing of the water field side after the adjacent single cells are stacked. The second support portion 131 can be extended when the hydrogen chamber seal 13 is injection molded, and is prepared using the same materials and processes as the hydrogen seal, or it can be prepared as an insert separately and then prepared using the same materials and processes as the hydrogen chamber insert 31.

[0089] In some embodiments, the anode monopolar plate 3 may also be provided with a first injection hole 15 to realize bilateral injection molding of a single cell. During bilateral injection molding, the first seal 4 is not injected on the side of the anode monopolar plate 3 facing the water field, and only the injection material flows between the anode monopolar plate 3 and the membrane electrode 2 through the first injection hole 15 and the first injection hole 15 is sealed. When multiple cells are assembled, the sealing portion of the cathode monopolar plate 1 facing the water field side (including part of the first seal 4, the oxygen chamber seal 12 and the hydrogen chamber seal 13) can be in contact with the plate material of the anode monopolar plate 3 instead of the sealing material.

[0090] As shown in Figures 11 to 22, in this embodiment, the thickness of the membrane electrode 2 frame is 0.25 mm, the thickness of the proton membrane is 0.05 mm, the thickness of the cathode GDL (diffusion layer) after 20% compression is 0.1 mm, and the thickness of the anode GDL (diffusion layer) after 20% compression is 0.1 mm. The height c1 of the second raised portion 33, the height d1 of the hydrogen chamber insert 31, and the height c2 of the anode-side flow field region 23 of the membrane electrode are all consistent, all 0.3 mm. The height b1 of the first raised portion 16 and the height d2 of the oxygen insert are consistent, both 0.19 mm. Both are 0.21 mm lower than the height b2 (0.4 mm) of the cathode-side flow field region 22 of the membrane electrode. The ridge height of the first raised portion 16 is 0.21 mm lower than the ridge height of the cathode-side flow field region 22 of the membrane electrode. The groove of the first raised portion 16 is higher than the groove height of the cathode-side flow field region 22 of the membrane electrode, ensuring sufficient compression space for the sealing portion injection-molded on the first raised portion 16. The height a1 of the edge seal on the first raised portion 16 is 0.3mm, and its designed compression rate is 30%, resulting in a compressed height of 0.21mm. The height a3 of the hydrogen chamber seal 13, after compression, is consistent with the sum of the compressed height a1 of the edge seal molded on the first raised portion 16 and the height b1 of the first raised portion. The height a2 of the oxygen chamber seal 12 is consistent with the height a1 of the edge seal molded on the first raised portion 16. The height a1 is 0.3mm, and after 30% compression, it is 0.21mm high. The height a2 is 0.3mm, and after 30% compression, it is 0.21mm high. The height a3 is 0.57mm, and after 30% compression, it is 0.4mm high. The height d3 of the first support portion 121 and the second support portion 131 is equal to the sum of the compressed height b1 of the first raised portion 16 and the height a1 of the edge seal on the first raised portion 16. The height d3 is 0.4mm. The compression ratio of the above sealing structures is between 20% and 40%.

[0091] As shown in Figures 23 and 24, in another embodiment, a cooling liquid channel 431 is provided on the side of the second raised portion 33 located near the flow field area of ​​the water cavity, so that the cooling liquid can flow along the cooling liquid channel 431 to the water field between the cathode monopolar plate 1 and the connected anode monopolar plate 3 for cooling. In this embodiment, the water cavity sealing portion 43 is not provided on the periphery of the water cavity opening on the water field side of the cathode monopolar plate 1. The adhesive coating area of ​​the water cavity sealing portion 43 is the side of the cathode monopolar plate 1 facing the membrane electrode 2, the side of the membrane electrode 2 facing the cathode monopolar plate 1 and the anode monopolar plate 3, and the side of the anode monopolar plate 3 facing the membrane electrode 2.

[0092] As shown in Figure 25 , in this embodiment, the thickness of the membrane electrode 2 frame is 0.25 mm, the thickness of the proton membrane is 0.05 mm, the cathode GDL (diffusion layer) is 0.1 mm thick after being compressed by 20%, and the thickness of the anode GDL (diffusion layer) is 0.1 mm thick after being compressed by 20%. The height c1 of the second protrusion 33 and the height d1 of the hydrogen chamber insert (not shown) are 0.05 mm higher than the height c2 (0.3 mm) of the flow field region 23 on the anode side of the membrane electrode, both being 0.35 mm, to accommodate the gap between the compressed height of the flow field region of the membrane electrode 2 and the frame height. The height c3 (c3 is 0.56mm, c3=c1+c2) of the second raised portion 33 close to the flow field area is 0.26mm higher than the height c2 of the flow field area 23 on the anode side of the membrane electrode. The ridge height of the second raised portion 33 is 0.21mm higher than the ridge height of the flow field area 23 on the anode side of the membrane electrode. The groove height of the second raised portion 33 is 0.05mm deeper than the groove height of the flow field area 23 on the anode side of the membrane electrode, so as to match the gap between the height of the flow field area of ​​the membrane electrode 2 after compression and the height of the frame, as well as the contact and fluid flow of the water cavity port of the cathode monopolar plate 1 during matching. The height b1 of the first raised portion 16 is 0.24 mm, and the height d2 of the oxygen chamber insert (not shown in the figure) is 0.24 mm. The height b1 of the first raised portion 16 and the height d2 of the oxygen chamber insert 11 are 0.16 mm lower than the height b2 (0.4 mm) of the flow field region 22 on the cathode side of the membrane electrode. The ridge height of the first raised portion 16 is 0.21 mm lower than the ridge height of the flow field region 22 on the cathode side of the membrane electrode. The groove height of the first raised portion 16 is 0.05 mm deeper than the groove height of the flow field region 22 on the cathode side of the membrane electrode, so as to match the gap between the height of the compressed flow field region of the membrane electrode 2 and the frame height, and to ensure that the edge sealing portion 44 injection-molded on the first raised portion 16 has sufficient compression space.

[0093] This embodiment also provides a fuel cell stack, comprising at least two stacked fuel cell cells. This embodiment directly connects the anode monopolar plate 3, the frame of the membrane electrode 2 and the cathode monopolar plate 1 together through injection molding, and opens a through hole on the air cavity plate to allow the gas to cross over and enter the respective flow fields. This structure has only an injection molding interface generated by the injection molding process for both the air cavity seal and the water cavity seal. In addition, there is a mechanical stress interface generated when multiple cells are stacked and assembled to form a stack. The types of sealing failures are reduced, the risks of external leakage and cross-leakage problems are reduced, the safety of the stack is effectively improved, and the efficiency of the stack is improved.

[0094] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A fuel cell cell, characterized in that: The single cell comprises a cathode monopolar plate, a membrane electrode and an anode monopolar plate which are stacked, and a first sealing member connecting the cathode monopolar plate, the membrane electrode and the anode monopolar plate; The first sealing member includes a hydrogen cavity sealing portion and an oxygen cavity sealing portion, wherein the hydrogen cavity sealing portion can seal the hydrogen cavity opening between the cathode monopolar plate and the membrane electrode and between the membrane electrode and the anode monopolar plate, and the oxygen cavity sealing portion can seal the oxygen cavity opening between the cathode monopolar plate and the membrane electrode and between the membrane electrode and the anode monopolar plate, and the hydrogen cavity sealing portion and the oxygen cavity sealing portion are integrally injection molded; The single cell further includes an oxygen cavity insert, an oxygen cavity seal and a hydrogen cavity seal are arranged on the cathode monopolar plate, the oxygen cavity seal and the hydrogen cavity seal are located on the side of the cathode monopolar plate away from the membrane electrode, and the oxygen cavity seal is arranged around the oxygen cavity opening of the cathode monopolar plate, and is located between the edge of the cathode monopolar plate and the oxygen cavity seal, and the hydrogen cavity seal is arranged around the hydrogen cavity opening of the cathode monopolar plate, and is located between the edge of the cathode monopolar plate and the hydrogen cavity seal; The oxygen chamber insert is located on the side of the cathode monopolar plate facing the membrane electrode, and a plurality of oxygen channels are provided on the oxygen chamber insert. A plurality of oxygen through holes are provided on the side of the oxygen chamber opening of the cathode monopolar plate close to the flow field area, and the plurality of oxygen through holes are located between the oxygen chamber seal and the oxygen chamber seal portion, and each of the oxygen channels is connected to each of the oxygen through holes; The single cell also includes a hydrogen chamber insert, which is located on the side of the anode monopolar plate facing the membrane electrode, and there are multiple hydrogen channels on the hydrogen chamber insert. A plurality of hydrogen through holes are provided on the side of the hydrogen chamber opening of the anode monopolar plate close to the flow field area, and the plurality of hydrogen through holes are located between the hydrogen chamber seal and the hydrogen chamber sealing portion, and each of the hydrogen channels is connected to each of the hydrogen through holes.

2. The fuel cell according to claim 1, characterized in that: The first sealing member further comprises a water cavity sealing portion, which is capable of sealing the water cavity openings between the cathode monopolar plate and the membrane electrode and between the membrane electrode and the anode monopolar plate; The water cavity sealing portion is also located at the water cavity opening on the side of the cathode monopolar plate away from the membrane electrode.

3. The fuel cell according to claim 2, characterized in that: The water cavity sealing portion located on the side of the cathode monopolar plate away from the membrane electrode is provided with a cooling liquid channel; The cooling liquid channel is located on a side of the water cavity sealing portion close to the flow field area.

4. The fuel cell according to claim 2, characterized in that: The first seal also includes an edge sealing portion, which is arranged at the edge between the cathode monopolar plate and the membrane electrode, the edge between the membrane electrode and the anode monopolar plate, and the edge of the cathode monopolar plate away from the membrane electrode.

5. The fuel cell according to claim 4, characterized in that: The outer edge and the cavity position of the cathode monopolar plate are provided with a first injection hole, the outer edge and the cavity position of the membrane electrode are provided with a second injection hole, and the first injection hole and the second injection hole are arranged opposite to each other; The hydrogen chamber sealing portion, the oxygen chamber sealing portion, the water chamber sealing portion and the edge sealing portion are arranged through the first injection hole and the second injection hole.

6. The fuel cell according to claim 5, characterized in that: A first protrusion is provided at the outer edge and the cavity position of the cathode monopolar plate, the first protrusion accommodates the first sealing member between the cathode monopolar plate and the membrane electrode, and the first injection hole is provided at the first protrusion; A second protrusion is provided at the outer edge and the cavity position of the anode monopolar plate, and the second protrusion accommodates the first sealing member between the membrane electrode and the anode monopolar plate.

7. The fuel cell according to claim 6, characterized in that: A cooling liquid channel is arranged on one side of the second protrusion located near the flow field area of ​​the water cavity.

8. The fuel cell according to claim 6, characterized in that: The height of the oxygen chamber insert is the same as the height of the first protrusion, and the oxygen chamber insert and the first protrusion are at least 2 mm apart; The height of the hydrogen chamber insert is the same as that of the second protrusion, and the hydrogen chamber insert and the second protrusion are spaced at least 2 mm apart.

9. The fuel cell according to claim 6, characterized in that: The height of the oxygen chamber sealing member after being compressed is equal to the height of the edge sealing portion located on the first protruding portion after being compressed; The compressed height of the hydrogen chamber sealing member is equal to the sum of the height of the first protruding portion and the compressed height of the edge sealing portion located on the first protruding portion.

10. The fuel cell according to claim 6, characterized in that: The oxygen chamber seal comprises a plurality of first support portions, and a first channel is formed between adjacent first support portions. The first channel can communicate with the oxygen chamber opening of the cathode monopolar plate and the oxygen through hole.

11. The fuel cell according to claim 10, characterized in that: The height of the first supporting portion is equal to the sum of the height of the first protruding portion and the height of the edge sealing portion on the first protruding portion after being compressed.

12. The fuel cell according to claim 6, characterized in that: The hydrogen chamber seal comprises a plurality of second support portions, and a second channel is formed between adjacent second support portions. The second channel can communicate with the hydrogen chamber opening of the cathode monopolar plate and the hydrogen through hole of the adjacent anode monopolar plate.

13. The fuel cell according to claim 12, characterized in that: The height of the second supporting portion is equal to the sum of the height of the first protruding portion and the height of the edge sealing portion on the first protruding portion after being compressed.

14. The fuel cell according to claim 4, characterized in that: The distance between the oxygen chamber sealing member and the oxygen chamber sealing portion is 1 mm to 5 mm, and the distance between the oxygen chamber sealing member and the edge sealing portion is 1 mm to 5 mm; The distance between the hydrogen chamber sealing member and the oxygen chamber sealing portion is 1 mm-5 mm, and the distance between the hydrogen chamber sealing member and the edge sealing portion is 1 mm-5 mm.

15. A fuel cell stack, characterized in that: The invention comprises at least two fuel cell cells stacked together, wherein the fuel cell cells are the fuel cell cells according to any one of claims 1 to 14.

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