CN113451599A

CN113451599A - Bipolar plate for hydrogen fuel cell

Info

Publication number: CN113451599A
Application number: CN202110709103.5A
Authority: CN
Inventors: 叶士海; 何海平; 刘映红; 邹海平
Original assignee: Ruida Hydrogen Energy Ganzhou Co ltd; Ruida New Energy Guangzhou Co ltd
Current assignee: Ruida Hydrogen Energy Ganzhou Co ltd; Ruida New Energy Guangzhou Co ltd
Priority date: 2021-06-25
Filing date: 2021-06-25
Publication date: 2021-09-28

Abstract

A bipolar plate for a hydrogen fuel cell relates to the technical field of design and manufacture of hydrogen fuel cells. The bipolar plate for the hydrogen fuel cell comprises an anode plate and a cathode plate, wherein a gap of the porous graphite plate is filled with a fluorine joint filling material, and the back of the anode plate is coupled with the back of the cathode plate to form a cooling flow field; when the back surfaces of the anode plate and the cathode plate are coupled, a first connecting line is formed by the first anode manifold port and the second anode manifold port, a second connecting line is formed by the first cathode manifold port and the second cathode manifold port, and the first connecting line and the second connecting line are arranged in a crossed mode; the grooves of the anode flow field and the grooves of the cooling flow field are arranged in an offset manner; the grooves of the cathode flow field and the grooves of the cooling flow field are arranged in an offset manner. According to the bipolar plate for the hydrogen fuel cell, the fluorine joint filling material is filled in the gaps of the porous graphite plate, so that the absorption of the graphite plate to moisture is reduced, the expansion rate is reduced, the graphite plate is prevented from being broken due to overlarge expansion pressure in a limited space, the initial working efficiency is greatly improved, and the proton membrane is prevented from being damaged.

Description

Bipolar plate for hydrogen fuel cell

Technical Field

The invention relates to the technical field of design and manufacture of hydrogen fuel cells, in particular to a bipolar plate for a hydrogen fuel cell.

Background

The hydrogen fuel cell is an environment-friendly cell with controllable output power, which utilizes hydrogen and oxygen to generate electricity and water through the chemical reaction of a catalyst. The basic principle is the reverse reaction of electrolyzed water, hydrogen and oxygen are supplied to the anode and cathode respectively, and after the hydrogen diffuses outwards through the anode and reacts with the catalyst, negative electrons are released to reach the cathode through an external load. As a novel power source, the hydrogen fuel cell has the characteristics of high efficiency, no pollution, no noise, continuous work and the like of a common fuel cell, and has the advantages of high power density, low working temperature, quick start, long service life and the like, so the hydrogen fuel cell has wide application prospect in the aspects of fixed power stations, electric automobiles, military, movable power supplies and the like.

The bipolar plate material is a core component of the fuel cell, and the performance of the bipolar plate material directly influences the working efficiency, the service life and the cost of the electric stack. The bipolar plate occupies 20-35% of the cost of the hydrogen fuel cell, not only has the conductive function of connecting the cell group, but also needs to separate reaction gas from cooling water, the designed flow channel enables the cooling water to take away heat generated in the working process of the cell, and the gas in the flow channel is more needed to be beneficial to the gas diffusion capacity of the membrane electrode. The bipolar plate is made of various materials, and among them, a graphite plate has excellent conductivity and corrosion resistance. However, in the working process, the graphite plate easily absorbs moisture contained in the gas, so that the expansion rate is high, the initial working efficiency of the bipolar plate is greatly influenced, and the probability of damaging the proton membrane is increased.

Disclosure of Invention

The invention provides a bipolar plate for a hydrogen fuel cell, which reduces the water absorption of a graphite plate, reduces the expansion rate, prevents the graphite plate from being broken due to overlarge expansion pressure in a limited space, greatly improves the initial working efficiency and avoids damaging a proton membrane by filling fluorine joint filling materials in gaps of a porous graphite plate.

The embodiment of the invention is realized by the following steps:

a bipolar plate for a hydrogen fuel cell comprises an anode plate and a cathode plate, wherein a gap of a porous graphite plate is filled with a fluorine joint filling material, the front side of the anode plate is provided with an anode flow field, the front side of the cathode plate is provided with a cathode flow field, and the back side of the anode plate and the back side of the cathode plate are coupled to form a cooling flow field;

the two ends of the anode plate are respectively and sequentially provided with 3 anode plate branch ports in the width direction, an anode flow field diffusion area is arranged between the anode plate branch ports and the anode flow field, the anode plate branch ports comprise a first anode branch port and a second anode branch port which are arranged diagonally, and the first anode branch port and the second anode branch port are communicated to the anode flow field diffusion area through a hydrogen inlet and a hydrogen outlet respectively; the second anode manifold port is lower than the anode flow field, and the groove of the anode flow field and the groove of the cooling flow field are arranged in an offset manner;

the two ends of the cathode plate are respectively and sequentially provided with 3 cathode plate branch ports in the width direction, a cathode flow field diffusion area is arranged between each cathode plate branch port and the cathode flow field, each cathode plate branch port comprises a first cathode branch port and a second cathode branch port which are arranged diagonally, and the first cathode branch port and the second cathode branch port are communicated to the cathode flow field diffusion area through an oxygen inlet and an oxygen outlet respectively; the second cathode manifold port is lower than the cathode flow field, and the groove of the cathode flow field and the groove of the cooling flow field are arranged in an offset manner;

when the back surfaces of the anode plate and the cathode plate are coupled, a first connecting line is formed by the first anode manifold port and the second anode manifold port, a second connecting line is formed by the first cathode manifold port and the second cathode manifold port, and the first connecting line and the second connecting line are arranged in a crossed mode; the anode plate manifold port and the cathode plate manifold port are arranged in a mirror image mode.

In a preferred embodiment of the present invention, the two cathode plate manifold ports and the two anode plate manifold ports disposed in the middle are respectively in one-to-one correspondence and coupled as a condensed water inlet and a condensed water outlet.

In a preferred embodiment of the present invention, the condensed water outlet is lower than the flow channel of the cooling flow field.

In a preferred embodiment of the present invention, the anode flow field diffusion region and the cathode flow field diffusion region include guide protrusions distributed in an array.

In a preferred embodiment of the present invention, the cathode plate manifold port and the anode plate manifold port are communicated to the cooling flow field through a cooling flow field diffusion region, and the cooling flow field diffusion region includes guide protrusions distributed in an array near the cooling flow field and guide grooves extending in a length direction away from the cooling flow field.

In a preferred embodiment of the present invention, the front surface of the anode plate and the front surface of the cathode plate have anti-vibration regions, and the anti-vibration regions are higher than the reference plane by the compressed thickness of the carbon paper.

In a preferred embodiment of the present invention, the compressed thickness of the carbon paper is 0.1mm to 0.17 mm.

In a preferred embodiment of the present invention, the fluorine caulking material has a tolerance temperature range of minus 35 ℃ to 260 ℃.

The embodiment of the invention has the beneficial effects that:

(1) the gap between the porous graphite plates of the anode plate and the cathode plate is filled with the fluorine joint filling material, so that the bipolar electrode for the hydrogen fuel cell has hydrophobicity and is difficult to absorb water, the expansion rate is further reduced, and the precision is ensured. Because the water contained in the gas is not easy to be absorbed by the bipolar plate in the primary work, the graphite plate is prevented from being broken due to overlarge expansion pressure in a limited space, the initial working efficiency of the whole battery is greatly improved, and the proton membrane is prevented from being damaged due to thirst in the primary work of the battery.

(2) The grooves of the cathode flow field and the grooves of the cooling flow field are arranged in an offset manner. The groove of the anode flow field and the groove of the cooling flow field are arranged in an offset way. The thickness of the whole electrode plate can be made to be the thinnest, and the electrode plate can not leak under the condition of ensuring the strength.

(3) The condensed water outlet is lower than the flow channel, so that water flow can flow into the confluence outlet to be discharged out of the pile by self gravity without gas pressure, and the blockage of the flow channel in the pile due to untimely water discharge caused by too high water level is avoided.

(4) The anode plate and the cathode plate are coupled to form a bipolar plate with a three-dimensional structure, so that zero clearance is formed after the membrane electrode and the bipolar plate are assembled to form a whole, the phenomenon that a clearance exists during stack assembly, the stack pressure is unbalanced, and the local damage is caused is avoided, the whole cell stack has no clearance after a plurality of bipolar plates are stacked, the anti-vibration performance is enhanced, and the high-low frequency airflow generated by the vibration of the inlet airflow and the cell stack can be ensured due to the no clearance during the membrane electrode bonding, so that the membrane electrode is not damaged or cracked.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic diagram of the front side of an anode plate according to an embodiment of the present invention;

FIG. 2 is an enlarged schematic view at A in FIG. 1;

FIG. 3 is a schematic view of the back side of an anode plate according to an embodiment of the present invention;

FIG. 4 is an enlarged schematic view at B of FIG. 3;

FIG. 5 is a schematic structural view of the front side of a cathode plate according to an embodiment of the present invention;

FIG. 6 is a schematic view of the construction of the back side of a cathode plate according to an embodiment of the present invention;

FIG. 7 is an enlarged schematic view at C of FIG. 6;

FIG. 8 is a schematic diagram of a configuration of an embodiment of the invention in which a cathode plate and an anode plate are coupled;

FIG. 9 is a schematic view of another embodiment of the anode plate front side of the present invention;

fig. 10 is another schematic view of the front side of the cathode plate in accordance with the present invention.

Icon: 110-an anode plate; 120-cathode plate; 111-an anode flow field; 121-a cathode flow field; 130-a cooling flow field; 112-anode flow field diffusion region; 113-a first anode manifold port; 114-a second anode manifold; 1131 — hydrogen inlet; 1141-hydrogen gas outlet; 122-cathode flow field diffusion region; 123-a first cathode manifold; 124-a second cathode manifold; 1231-oxygen intake; 1241-oxygen outlet; 115-first connection; 125-a second line; 131-a condensate inlet; 132-a condensate outlet; 133-cooling the flow field diffusion region; 140-flow guide bulges; 150-a flow directing structure; 160-grooves; 170-vibration-proof zone.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "first", "second", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Examples

Referring to fig. 1-7, the present embodiment provides a bipolar plate for a hydrogen fuel cell, which includes an anode plate 110 and a cathode plate 120. The gap between the porous graphite plates of the anode plate 110 and the cathode plate 120 is filled with a fluorine caulking material (not shown). The fluorine joint filling material can make the bipolar plate have hydrophobicity, so that the bipolar plate does not absorb moisture, the expansion rate is reduced, the graphite plate is prevented from being broken due to overlarge expansion pressure in a limited space, and the precision is ensured. Because the moisture contained in the gas is not absorbed by the bipolar plate in the primary operation, the primary operation efficiency is greatly improved and the damage of the proton membrane caused by thirst is avoided in the primary operation of the battery. And the tolerance temperature range of the fluorine joint filling material is 35-260 ℃ below zero, so that the risks of hydrogen leakage in a low-temperature environment and carbonization or aging of the material at a high temperature caused by the inconsistency of the low-temperature shrinkage rate of the material with that of the parent material can be effectively avoided. An anode flow field 111 is provided on the front surface of the anode plate 110. A cathode flow field 121 is provided on the front side of cathode plate 120. And, the back of anode plate 110 and the back of cathode plate 120 are coupled to form a cooling flow field 130.

Referring to fig. 1-4, two ends of the anode plate 110 are respectively provided with 3 branches of the anode plate 110 in the width direction. An anode flow field diffusion region 112 is arranged between the manifold port of the anode plate 110 and the anode flow field 111. The anode plate 110 manifold includes a first anode manifold 113 and a second anode manifold 114 arranged diagonally. The first anode manifold port 113 and the second anode manifold port 114 are respectively communicated to the anode flow field diffusion region 112 through a hydrogen inlet 1131 and a hydrogen outlet 1141. The second anode manifold port 114 is lower than the anode flow field 111 to facilitate the discharge of water generated during the operation of the fuel cell due to free fall.

Referring to fig. 5-7, two ends of the cathode plate 120 are respectively provided with 3 manifold ports of the cathode plate 120 in sequence in the width direction. A cathode flow field diffusion region 122 is disposed between the manifold port of the cathode plate 120 and the cathode flow field 121. The cathode plate 120 manifold includes a first cathode manifold 123 and a second cathode manifold 124 arranged diagonally. The first and

second cathode manifolds

123, 124 are communicated to the cathode flow field diffusion region 122 via oxygen inlets 1231 and oxygen outlets 1241, respectively. The second cathode manifold 124 is lower than the cathode flow field 121 to facilitate the discharge of water generated during the operation of the fuel cell due to free fall.

With continued reference to fig. 1 and 5, the anode plate 110 and the cathode plate 120 are coupled at their back sides. The first anode manifold port 113 and the second anode manifold port 114 form a first connection line 115. The first cathode manifold 123 and the second cathode manifold 124 form a second connection line 125. The first wire 115 and the second wire 125 are arranged to cross each other. Referring to fig. 3, 4, 6-8, the grooves 160 of the anode flow field 111 and the grooves 160 of the cooling flow field 130 of the anode plate 110 are offset. The grooves 160 of the cathode flow field 121 and the grooves 160 of the cooling flow field 130 of the cathode plate 120 are also offset. The deviation arrangement can make the thickness of the whole electrode plate be the thinnest, and the electrode plate can not leak under the condition of ensuring the strength. The manifold of anode plate 110 is mirrored with the manifold of cathode plate 120. The two cathode plate 120 manifold ports and the two anode plate 110 manifold ports arranged in the middle are respectively in one-to-one correspondence and are coupled into two groups of manifold ports, and each group comprises one cathode plate 120 manifold port and one anode plate 110 manifold port which are arranged in a mirror image mode. The two groups of branch ports are respectively a condensed water inlet 131 and a condensed water outlet 132. Wherein the condensed water outlet 132 is lower than the flow channels of the cooling flow field 130. The condensed water outlet 132 is lower than the flow channel, so that water flow can flow into the confluence outlet to be discharged out of the pile by self gravity without gas pressure, and the blockage of the flow channel in the pile due to untimely water discharge caused by too high water level is avoided.

In the actual use process, the back surfaces of the anode plate 110 and the cathode plate 120 are coupled to form a bipolar plate for the hydrogen fuel cell with a three-dimensional structure, a plurality of groups of bipolar plates for the hydrogen fuel cell are arranged in series and stacked, and the bipolar plates are beneficial to forming a zero clearance after the membrane electrode and the bipolar plates are assembled to form a whole body, so that the phenomenon that the stack is pressed to be unbalanced in stress and cause local damage is avoided, the whole cell stack has no clearance after the bipolar plates are stacked, the shockproof performance is enhanced, and the membrane electrode is bonded without clearance, so that high-low-frequency airflow generated by the vibration of the inlet airflow and the cell stack can be ensured, and the membrane electrode is not damaged or cracked.

It should be noted that, in the present embodiment, please refer to the anode flow field diffusion region 112 and the cathode flow field diffusion region 122 including the guide protrusions 140 distributed in an array. In other embodiments, other forms of the flow guiding structure 150 may also be adopted, and the flow guiding effect of the present embodiment is within the protection scope of the present embodiment as long as the flow guiding effect of the present embodiment can be achieved.

Referring to fig. 3, 4, 6 and 7, on the back of the anode plate 110 and the cathode plate 120, the manifold of the cathode plate 120 and the manifold of the anode plate 110 communicate with the cooling flow field 130 through the cooling flow field diffusion region 133. The cooling flow field diffusion region 133 includes a guide protrusion 140 and a guide groove connected in sequence. The flow guide protrusions 140 are disposed near the cooling flow field 130 and distributed in an array. The channels extend lengthwise away from the cooling flow field 130. In the present embodiment, the cooling flow field diffusion region 133 includes guide protrusions 140 and guide grooves. In other embodiments, other forms of the flow guiding structure 150 may also be adopted, and the technical effect of the flow guiding of the present embodiment is within the protection scope of the present embodiment as long as the technical effect can be achieved.

Referring to fig. 9 and 10, it should be further noted that, in the present embodiment, the front surfaces of the anode plate 110 and the cathode plate 120 have anti-vibration regions 170 (black filling in the figure), and the anti-vibration regions 170 are higher than the reference plane by the compressed thickness of the carbon paper. The membrane electrode supporting cabinet plate is not vibrated by the arrangement, so that the mechanical damage of the membrane electrode can be prevented, and the gas leakage after the membrane electrode is broken can be prevented. Specifically, in this example, the compressed thickness of the carbon paper was 0.1mm to 0.17mm, and the compression ratio was about 85%.

In summary, the present invention relates to a bipolar plate for a hydrogen fuel cell, in which a gap between a porous graphite plate of an anode plate and a porous graphite plate of a cathode plate of the bipolar plate for a hydrogen fuel cell is filled with a fluorine caulking material, so that the bipolar plate for a hydrogen fuel cell of the present invention has hydrophobicity and is not easy to absorb water, thereby reducing swelling rate and ensuring accuracy. Because the water contained in the gas is not easy to be absorbed by the bipolar plate in the primary work, the graphite plate is prevented from being broken due to overlarge expansion pressure in a limited space, the initial working efficiency of the whole battery is greatly improved, and the proton membrane is prevented from being damaged due to thirst in the primary work of the battery. The deviation arrangement among the grooves of the cathode flow field, the cooling flow field and the anode flow field can ensure that the thickness of the whole electric bipolar plate is the thinnest, and the leakage is avoided under the condition of ensuring the strength. The condensed water outlet is lower than the flow channel, so that water flow can flow into the confluence outlet to be discharged out of the pile by self gravity without gas pressure, and the blockage of the flow channel in the pile due to untimely water discharge caused by too high water level is avoided. The anode plate and the cathode plate are coupled to form a bipolar plate with a three-dimensional structure, so that zero clearance is formed after the membrane electrode and the bipolar plate are assembled to form a whole, the phenomenon that a clearance exists during stack assembly, the stack pressure is unbalanced, and the local damage is caused is avoided, the whole cell stack has no clearance after a plurality of bipolar plates are stacked, the anti-vibration performance is enhanced, and the high-low frequency airflow generated by the vibration of the inlet airflow and the cell stack can be ensured due to the no clearance during the membrane electrode bonding, so that the membrane electrode is not damaged or cracked.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A bipolar plate for a hydrogen fuel cell is characterized by comprising an anode plate and a cathode plate, wherein a gap of a porous graphite plate is filled with a fluorine joint filling material, the front side of the anode plate is provided with an anode flow field, the front side of the cathode plate is provided with a cathode flow field, and the back side of the anode plate is coupled with the back side of the cathode plate to form a cooling flow field;

the two ends of the anode plate are respectively and sequentially provided with 3 anode plate branch ports in the width direction, an anode flow field diffusion region is arranged between the anode plate branch ports and the anode flow field, the anode plate branch ports comprise a first anode branch port and a second anode branch port which are arranged diagonally, the first anode branch port and the second anode branch port are communicated to the anode flow field diffusion region through a hydrogen inlet and a hydrogen outlet respectively, and a groove of the anode flow field and a groove of the cooling flow field are arranged in an offset manner;

the two ends of the cathode plate are respectively and sequentially provided with 3 cathode plate branch ports in the width direction, a cathode flow field diffusion area is arranged between the cathode plate branch ports and the cathode flow field, the cathode plate branch ports comprise a first cathode branch port and a second cathode branch port which are arranged diagonally, and the first cathode branch port and the second cathode branch port are communicated to the cathode flow field diffusion area through an oxygen inlet and an oxygen outlet respectively; the second cathode manifold port is lower than the cathode flow field, and the groove of the cathode flow field and the groove of the cooling flow field are arranged in an offset manner;

when the back surfaces of the anode plate and the cathode plate are coupled, the first anode manifold port and the second anode manifold port form a first connecting line, the first cathode manifold port and the second cathode manifold port form a second connecting line, and the first connecting line and the second connecting line are arranged in a crossed mode; the anode plate manifold port and the cathode plate manifold port are arranged in a mirror image mode.

2. The bipolar plate for a hydrogen fuel cell according to claim 1, wherein two cathode plate manifold ports and two anode plate manifold ports provided in the middle are respectively in one-to-one correspondence and coupled as a condensed water inlet and a condensed water outlet.

3. A bipolar plate for a hydrogen fuel cell as set forth in claim 2, wherein said condensed water outlet is lower than the flow channels of said cooling flow field.

4. The bipolar plate for a hydrogen fuel cell according to claim 1, wherein the anode flow field diffusion region and the cathode flow field diffusion region comprise an array of guide protrusions.

5. The bipolar plate for a hydrogen fuel cell according to claim 1, wherein the cathode plate manifold port and the anode plate manifold port communicate with a cooling flow field through a cooling flow field diffusion region, the cooling flow field diffusion region comprising guide protrusions arranged in an array near the cooling flow field and guide grooves extending in a length direction away from the cooling flow field.

6. The bipolar plate for a hydrogen fuel cell according to claim 1, wherein the front surface of the anode plate and the front surface of the cathode plate have an anti-vibration region which is higher than a reference plane by a carbon paper compression thickness.

7. The bipolar plate for a hydrogen fuel cell according to claim 6, wherein the compressed thickness of the carbon paper is 0.1mm to 0.17 mm.

8. The bipolar plate for a hydrogen fuel cell according to claim 1, wherein the fluorine caulking material has a withstand temperature in a range of 35 ℃ to 260 ℃ below zero.