Graphite bipolar plate of fuel cell

Abstract

The utility model relates to the technical field of fuel cells, and discloses a fuel cell graphite bipolar plate which comprises a plate body provided with a hydrogen channel; the plate body is provided with a front plate face and an auxiliary plate face. The first sealing groove is formed in the front plate surface and surrounds the hydrogen channel; the hydrogen flow groove is formed in the auxiliary plate surface, and the end part is communicated with the hydrogen channel; the groove body at the end part of the hydrogen flow groove is a deep groove, the rest groove bodies are shallow grooves, the deep groove and the shallow grooves are step-shaped, and the depth of the deep groove is greater than that of the shallow grooves; the second sealing groove is formed in the auxiliary plate surface and surrounds and encloses the hydrogen flow groove and the hydrogen channel; according to the graphite bipolar plate of the fuel cell provided by the utility model, the first sealing groove and the second sealing groove are arranged, so that good sealing is ensured, and compared with surface sealing and line sealing, the graphite bipolar plate has better sealing performance, is not easy to deform and is easier to seal and use; after the colloid is extruded to enter the deep groove, the hydrogen flow groove cannot be blocked, the deep groove plays a role in space compensation, and practicability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to a fuel cell graphite bipolar plate. Background Art

[0002] The bipolar plate is one of the core components of a fuel cell and has a great influence on the performance and cost of the battery. The graphite bipolar plate is the most commonly used bipolar plate at present, and its performance such as electrical conductivity, thermal conductivity, stability and corrosion resistance is excellent.

[0003] In the prior art, the graphite bipolar plate of a fuel cell is strengthened by a plastic frame, and the seal between the graphite bipolar plate and the plastic frame is often realized by means of a sealing rubber ring. The sealing performance is poor and it is not easy to use. In addition, when the battery stack is assembled, the sealing glue will be squeezed, causing it to enter the hydrogen flow channels in the bipolar plate, resulting in the blockage of the hydrogen flow channels and uneven battery performance. Summary of the Utility Model

[0004] In view of this, the utility model provides a fuel cell graphite bipolar plate to solve the problems that the graphite bipolar plate of a fuel cell is not conducive to sealing and the hydrogen flow channels are not smooth.

[0005] The utility model provides a fuel cell graphite bipolar plate, including: a plate body, on which a hydrogen channel is penetrated; the plate body has a positive plate surface and a negative plate surface located on opposite sides; a first sealing groove, opened at the positive plate surface and surrounding and enclosing the hydrogen channel, suitable for linearly sealing the hydrogen channel to prevent gas leakage; a hydrogen flow groove, opened at the negative plate surface, and the end part thereof is communicated with the hydrogen channel; wherein, the groove body at the end part of the hydrogen flow groove close to the hydrogen channel is a deep groove, and the rest of the groove body of the hydrogen flow groove is a shallow groove, the deep groove and the shallow groove are arranged in a stepped manner, and the depth of the deep groove is greater than the depth of the shallow groove; a second sealing groove, opened at the negative plate surface and surrounding and enclosing the hydrogen flow groove and the hydrogen channel.

[0006] Advantageous Effects: By providing the first sealing groove surrounding the hydrogen channel and the second sealing groove surrounding the hydrogen channel and the hydrogen flow groove, hydrogen leakage can be effectively prevented, ensuring good sealing of the bipolar plate. At the same time, compared with the existing planar sealing form, the linear sealing has better sealing performance, is not easy to deform, is easy to operate, and is more suitable for the sealing use of the bipolar plate; the groove bodies at both ends of the hydrogen flow groove are deep grooves. After the colloid is squeezed into the deep groove, it will not block the hydrogen flow groove, that is, the deep groove plays a role of compensation space. After the battery stack is assembled, the hydrogen flow groove can still remain unobstructed, ensuring uniform battery performance and strong practicability.

[0007] In an alternative embodiment, at least two hydrogen channels are arranged in parallel and spaced apart at the plate body; both ends of the hydrogen gas flow groove are respectively communicated with at least two of the hydrogen channels, and the deep groove is connected to the hydrogen channel.

[0008] In an alternative embodiment, it further includes an air flow groove, and a plurality of air flow grooves are arranged in parallel and spaced apart at the front plate surface of the plate body; the plurality of air flow grooves are located between at least two of the hydrogen channels.

[0009] In an alternative embodiment, the depth difference between the deep groove and the shallow groove is H, where: 0.3 mm ≤ H ≤ 3 mm.

[0010] In an alternative embodiment, the length of the deep groove is L, where: 3 mm ≤ L ≤ 4 mm.

[0011] In an alternative embodiment, the depth of the first sealing groove is D1, where: 0.2 mm ≤ D1 ≤ 2 mm; the depth of the second sealing groove is D2, where: 0.2 mm ≤ D2 ≤ 2 mm.

[0012] In an alternative embodiment, a plurality of the hydrogen gas flow grooves are arranged in parallel and spaced apart, and both ends are connected to the hydrogen channel.

[0013] In an alternative embodiment, the extending direction of the air flow groove is perpendicular to the extending direction of the hydrogen gas flow groove.

[0014] In an alternative embodiment, the cross-sectional shape of the first sealing groove is any one or a combination of more than one of the following: rectangle, triangle, trapezoid, sector; the cross-sectional shape of the second sealing groove is any one or a combination of more than one of the following: rectangle, triangle, trapezoid, sector. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic structural diagram of the fuel cell graphite bipolar plate of the present invention;

[0017] Figure 2 It is a schematic diagram of the front plate surface of the fuel cell graphite bipolar plate of the present invention;

[0018] Figure 3This is a side view of the graphite bipolar plate of the fuel cell of the present utility model;

[0019] Figure 4 This is a schematic diagram of the secondary surface of the graphite bipolar plate of the fuel cell of the present utility model.

[0020] Description of reference numerals:

[0021] 1. Plate body; 11. Positive surface; 12. Secondary surface; 2. Hydrogen channel; 3. First sealing groove; 4. Hydrogen flow groove; 41. Deep groove; 42. Shallow groove; 5. Second sealing groove; 6. Air flow groove. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0023] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0024] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0025] In addition, the technical features involved in different embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0026] Below, in combination with Figures 1 to 4 , describe the embodiments of the present utility model.

[0027] According to an embodiment of the present utility model, a fuel cell graphite bipolar plate is provided, including: a plate body 1, through which a hydrogen channel 2 penetrates; the plate body 1 has a positive plate surface 11 and a secondary plate surface 12 located on opposite sides; a first sealing groove 3, opened at the positive plate surface 11 and surrounding the hydrogen channel 2, adapted to seal the hydrogen channel 2 to prevent gas leakage, and the sealing method is line sealing; a hydrogen gas flow groove 4, opened at the secondary plate surface 12, and the end is communicated with the hydrogen channel 2; wherein, the groove body at the end of the hydrogen gas flow groove 4 close to the hydrogen channel 2 is a deep groove 41, and the remaining groove body of the hydrogen gas flow groove 4 is a shallow groove 42, the deep groove 41 and the shallow groove 42 are arranged in a stepped manner, and the depth of the deep groove 41 is greater than the depth of the shallow groove 42 to provide a compensation space to prevent the hydrogen gas flow channel from being blocked due to the squeezing of the sealant; a second sealing groove 5, opened at the secondary plate surface 12 and surrounding the hydrogen gas flow groove 4 and the hydrogen channel 2, for sealing the hydrogen gas flow channel to prevent gas leakage, and the sealing method is line sealing.

[0028] The specific setting form of the hydrogen gas flow channel is that at least two hydrogen channels 2 are arranged in parallel and spaced apart on the plate body 1; both ends of the hydrogen gas flow groove 4 are respectively communicated with at least two hydrogen channels 2, and the deep groove 41 is connected to the hydrogen channel 2.

[0029] The fuel cell graphite bipolar plate further includes an air flow groove 6, and a plurality of air flow grooves 6 are arranged in parallel and spaced apart on the positive plate surface 11 of the plate body 1; the plurality of air flow grooves 6 are located between at least two hydrogen channels 2 for air to flow through.

[0030] Before the fuel cell graphite bipolar plate is used, a plastic frame needs to be installed on the outside of the bipolar plate to enhance the strength of the plate body 1. Among them, the plate body 1 is installed together with the plastic frame. To prevent hydrogen leakage, sealing treatment needs to be performed between the positive plate surface 11, the secondary plate surface 12 and the plastic frame, that is, line sealing is carried out by means of the first sealing groove 3 and the second sealing groove 5; sealing strips are installed at the first sealing groove 3 and the second sealing groove 5. The first sealing groove 3 surrounds the hydrogen channel 2, and the second sealing groove 5 surrounds the hydrogen channel 2 and the hydrogen gas flow groove 4, which can effectively prevent hydrogen leakage, ensure good sealing of the bipolar plate. At the same time, compared with the existing planar sealing form, the line sealing has better sealing performance, is not easy to deform, is easy to operate, and is more suitable for the sealing use of the bipolar plate; when the battery stack is assembled, after the sealant used is squeezed, part of the colloid will enter the hydrogen gas flow groove 4 from the edge. Among them, the groove bodies at both ends of the hydrogen gas flow groove 4 are deep grooves 41, and the colloid will not block the hydrogen gas flow groove 4 after entering the deep groove 41, that is, the deep groove 41 plays a role of compensation space. After the battery stack is assembled, the hydrogen gas flow groove 4 can still remain unobstructed, ensuring uniform battery performance and strong practicability.

[0031] In this embodiment, by providing the first sealing groove 3 that surrounds the hydrogen channel 2 and the second sealing groove 5 that surrounds the hydrogen channel 2 and the hydrogen through-groove, hydrogen leakage can be effectively prevented, ensuring good sealing of the bipolar plate. At the same time, compared with the existing planar sealing form, the line sealing has better sealing performance, is not easily deformed, is easy to operate, and is more suitable for use in bipolar plate sealing; the groove bodies at both ends of the hydrogen flow groove 4 are both deep grooves 41. After the colloid is squeezed into the deep grooves 41, it will not block the hydrogen flow groove 4, that is, the deep grooves 41 play a role of compensation space. After the battery stack is assembled, the hydrogen flow groove 4 can still remain unblocked, ensuring uniform battery performance and strong practicability.

[0032] Optionally, the depth difference between the deep groove 41 and the shallow groove 42 is H, where the value range of H is between 0.3 and 3 mm, and the length of the deep groove 41 is L, where the value range of L is between 3 and 4 mm. The depth difference between the deep groove 41 and the shallow groove 42 and the length of the deep groove 41 can be selected according to the actual amount of colloid that will overflow, that is, the size of the compensation space is determined.

[0033] Optionally, the depth of the first sealing groove 3 is D1, where the value range of D1 is between 0.2 and 2 mm and can be selected according to actual requirements; the depth of the second sealing groove 5 is D2, where the value range of D2 is between 0.2 and 2 mm and can be selected according to actual requirements.

[0034] Optionally, the width of the air flow groove 6 has a value range between 0.8 and 2 mm, and the depth has a value range between 1 and 5 mm; the width of the hydrogen flow groove 4 has a value range between 0.5 and 3 mm, and the depth has a value range between 0.2 and 1.5 mm.

[0035] Optionally, the cross-sectional shape of the first sealing groove 3 is any one or a combination of the following forms: rectangle, triangle, trapezoid, sector. In this embodiment, the cross-sectional shape of the first sealing groove 3 is a rectangle; the cross-sectional shape of the second sealing groove 5 is any one or a combination of the following forms: rectangle, triangle, trapezoid, sector. In this embodiment, the cross-sectional shape of the second sealing groove 5 is a rectangle.

[0036] In some embodiments, as shown in combination with Figure 4 a plurality of the hydrogen flow grooves 4 are arranged in parallel and at intervals, and both ends are connected to the hydrogen channel 2 to ensure smooth hydrogen flow.

[0037] In some embodiments, as shown in combination with Figures 1 - 4 the extending direction of the air flow groove 6 is perpendicular to the extending direction of the hydrogen flow groove 4, and the extending direction of the hydrogen channel 2 is parallel to the extending direction of the air flow groove 6.

[0038] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A fuel cell graphite bipolar plate, characterized in that: include: A plate body (1) having a hydrogen channel (2) running through it; the plate body (1) has a main plate surface (11) and a secondary plate surface (12) located on two opposite sides; A first sealing groove (3) is provided on the front plate surface (11) and surrounds the hydrogen channel (2), and is suitable for linearly sealing the hydrogen channel (2) to prevent gas leakage; A hydrogen flow groove (4) is provided on the auxiliary plate surface (12), and an end portion thereof is communicated with the hydrogen channel (2); The groove body of the hydrogen flow groove (4) at the end close to the hydrogen channel (2) is a deep groove (41), and the rest of the groove body of the hydrogen flow groove (4) is a shallow groove (42). The deep groove (41) and the shallow groove (42) are arranged in a stepped manner, and the depth of the deep groove (41) is greater than the depth of the shallow groove (42); The second sealing groove (5) is formed on the auxiliary plate surface (12) and surrounds the hydrogen flow groove (4) and the hydrogen channel (2).

2. The fuel cell graphite bipolar plate according to claim 1, characterized in that: At least two hydrogen channels (2) are arranged in parallel and at intervals on the plate body (1); Both ends of the hydrogen flow groove (4) are respectively connected to at least two of the hydrogen channels (2), and the deep groove (41) is connected to the hydrogen channels (2).

3. The fuel cell graphite bipolar plate according to claim 2, characterized in that: It also includes air flow grooves (6), wherein a plurality of air flow grooves (6) are arranged in parallel and at intervals on the front surface (11) of the plate body (1); The plurality of air flow grooves (6) are located between at least two of the hydrogen channels (2).

4. The fuel cell graphite bipolar plate according to claim 1, characterized in that: The depth difference between the deep groove (41) and the shallow groove (42) is H, wherein: 0.3 mm≤H≤3 mm.

5. The fuel cell graphite bipolar plate according to claim 4, characterized in that: The length of the deep groove (41) is L, wherein: 3mm≤L≤4mm.

6. The fuel cell graphite bipolar plate according to claim 1, characterized in that: The depth of the first sealing groove (3) is D1, wherein: 0.2 mm ≤ D1 ≤ 2 mm; The depth of the second sealing groove (5) is D2, wherein: 0.2 mm≤D2≤2 mm.

7. The fuel cell graphite bipolar plate according to claim 3, characterized in that: The plurality of hydrogen flow grooves (4) are arranged in parallel and at intervals, and the ends of the plurality of hydrogen flow grooves (4) are connected to the hydrogen channel (2).

8. The fuel cell graphite bipolar plate according to claim 7, characterized in that: The extension direction of the air flow groove (6) is arranged perpendicular to the extension direction of the hydrogen flow groove (4).

9. The fuel cell graphite bipolar plate according to claim 1, characterized in that: The cross-sectional shape of the first sealing groove (3) is any one or more of the following combinations: rectangular, triangular, trapezoidal, or sector-shaped; The cross-sectional shape of the second sealing groove (5) is any one or more of the following combinations: rectangular, triangular, trapezoidal, and sector-shaped.

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