CN114695909A

CN114695909A - Unipolar plate, bipolar plate and fuel cell

Info

Publication number: CN114695909A
Application number: CN202011607455.1A
Authority: CN
Inventors: 杨新春; 亓峰; 何难
Original assignee: Shanghai De'er New Energy Technology Co ltd
Current assignee: Shanghai De'er New Energy Technology Co ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-07-01
Anticipated expiration: 2040-12-30
Also published as: CN114695909B

Abstract

The application discloses unipolar plate, bipolar plate and fuel cell, unipolar plate includes: the single-pole plate comprises a single-pole plate body and a plurality of convex parts which are convex towards one side of the single-pole plate body; the plurality of bosses comprise at least one first boss positioned in the center of the unipolar plate body and a plurality of second bosses positioned on two sides of the at least one first boss; wherein the height of the first boss is greater than the height of the second boss. The height that this application is located at least one first bellying of unipolar plate body central part through the setting is greater than the height that is located a plurality of second bellying of this at least one first bellying both sides, and when a plurality of unipolar plates carried out the pressfitting, the effort that increases between two adjacent unipolar plate central parts, and then increased unipolar plate central part's packing force for membrane electrode assembly and unipolar plate closely laminate, realize improving fuel cell current density and current strength's technological effect.

Description

Unipolar plate, bipolar plate and fuel cell

Technical Field

The application relates to the technical field of new energy, in particular to a unipolar plate, a bipolar plate and a fuel cell.

Background

The fuel cell is a device for directly converting chemical energy of an oxidant and a reducing agent into electric energy through electrocatalysis reaction, and is a novel power generation technology which is efficient, safe, clean and flexible. When manufacturing a fuel cell, two unipolar plates and a membrane electrode assembly arranged on the two unipolar plates are required to be welded into a bipolar plate, and then a plurality of bipolar plates are pressed into a stack. When welding between the unipolar plates, firstly, two unipolar plates and the membrane electrode assembly are overlapped and placed on the base, then, the pressing block is utilized to press down to enable the two unipolar plates to be tightly attached, then, the two unipolar plates and the membrane electrode assembly are welded through the welding device to form the bipolar plate, then, the bipolar plates are stacked to form the electric pile, the outer edge of the bipolar plate is fixedly connected through the bolts, and the electric pile is further fixed and compressed.

However, the above-described fuel cell manufacturing method has the following problems: the bolts only compress the outer edge of the bipolar plate but not the middle part of the bipolar plate, so that the middle pressing force of the bipolar plate is insufficient, the membrane electrode assembly and the two unipolar plates are not tightly pressed, and the problems of low electricity density, low current intensity and the like of the fuel cell are caused.

Therefore, it is urgently needed to provide a unipolar plate, a bipolar plate and a fuel cell, and the technical problems of low electricity density, low current intensity and the like of the fuel cell caused by insufficient pressing force of the middle part of the bipolar plate in the prior art are solved.

Disclosure of Invention

The application provides a unipolar plate, bipolar plate and fuel cell, aims at solving the bipolar plate middle part packing force that exists among the prior art and is not enough, causes fuel cell electric density low, current strength low grade technical problem.

In a first aspect, the present application provides a unipolar plate for forming a bipolar plate, the unipolar plate comprising: the single-pole plate comprises a single-pole plate body and a plurality of convex parts which are convex towards one side of the single-pole plate body; the plurality of bosses comprise at least one first boss positioned at the center of the unipolar plate body and a plurality of second bosses positioned at the edges of the unipolar plate body;

wherein the height of the first boss is greater than the height of the second boss.

In some implementations of the present application, a difference in height between the first and second protrusions is 80 μm to 120 μm.

In some implementations of the present application, a difference in height between the first and second protrusions is 100 μm.

In some implementations of the present application, the height of the lobes decreases gradually in a direction from the unipolar plate body center location to the unipolar plate body edge location.

In some implementations of the present application, a cross-sectional area of the first boss is the same as a cross-sectional area of the second boss.

In some implementations of the present application, the opening width of the second boss is greater than the opening width of the first boss.

In some implementations of the present application, the opening width of the protrusion gradually increases in a direction from the center of the unipolar plate body to the edge of the unipolar plate body.

In some implementations of the present application, the plurality of lobes are equally spaced apart.

In some implementations of the present application, the protrusion includes a first side, a second side, and a top side, the first side with one end fixed connection of the second side in the unipolar plate body, the first side with the other end fixed connection of the second side in the top side, the first side with the second side with the included angle of the top side is not less than 90 °.

In some implementations of the present application, the first side edge and the top edge, the second side edge and the top edge, the first side edge and the unipolar plate body, the second side edge and transition between the unipolar plate bodies is all through chamfer or fillet.

In some implementations of the present application, the protrusion is rectangular or trapezoidal.

In a second aspect, the present application provides a bipolar plate, which includes a first unipolar plate and a second unipolar plate disposed opposite to the first unipolar plate, where the first unipolar plate, and/or the second unipolar plate is the unipolar plate described in any one of the implementations of the first aspect.

In a third aspect, the present application provides a fuel cell comprising the unipolar plate described in any one of the implementations of the first aspect.

The height that this application is located at the at least one first bellying of unipolar board body central part through the setting is greater than the height that is located a plurality of second bellying of unipolar board body edge part, when a plurality of unipolar boards carry out the pressfitting, increases the effort between two adjacent unipolar board central parts, and then increases the packing force of unipolar board central part for membrane electrode assembly and unipolar board closely laminate, realize improving fuel cell current density and current strength's technological effect.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic view of a first configuration of a unipolar plate provided in an embodiment of the present application;

fig. 2 is a schematic diagram of a second configuration of a unipolar plate provided in an embodiment of the present application;

fig. 3 is a schematic view of a third configuration of a unipolar plate provided in an embodiment of the present application;

FIG. 4 is a schematic structural view of a boss provided in an embodiment of the present application;

FIG. 5 is a schematic structural view of a bipolar plate provided in an embodiment of the present application;

figure 6 is a top view of a bipolar plate provided in an embodiment of the present application.

The fuel cell comprises a 100 unipolar plate, a 110 unipolar plate body, a 120 convex portion, a 121 first convex portion, a 122 second convex portion, a 123 first side edge, a 124 second side edge, a 125 top edge, a 200 first flow-through space, a 300 second flow-through space, a 10 bipolar plate, a 11 first unipolar plate, a 12 second unipolar plate, a 1 fuel cell, a height of an H1 first convex portion 121, a height of an H2 second convex portion 122, an opening width of an L1 first convex portion 121, and a width of an L2 second convex portion 122.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In this application, the word "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the invention. In the following description, details are set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and processes are not shown in detail to avoid obscuring the description of the invention with unnecessary detail. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Embodiments of the present invention provide a unipolar plate, a bipolar plate, and a fuel cell, which are described in detail below.

Example one

As shown in fig. 1, the present embodiment provides a unipolar plate 100. The unipolar plate 100 includes: a unipolar plate body 110 and a plurality of protrusions 120 protruding toward one side of the unipolar plate body 110; the plurality of bosses 120 include at least one first boss 121 located at a central portion of the unipolar plate body 110 and a plurality of second bosses 122 located at edge portions of the unipolar plate body 110;

wherein, the height H1 of the first protrusion 121 is greater than the height H2 of the second protrusion 122.

In the embodiment of the present application, by setting the height H1 of at least one first protrusion 121 located at the center of the unipolar plate body 110 to be greater than the height H2 of the plurality of second protrusions 122 located at the edge of the unipolar plate body 110, when the plurality of unipolar plates 100 are pressed, the acting force between the center of two adjacent unipolar plates 100 is increased, and further, the pressing force at the center of the unipolar plate 100 is increased, so that the membrane electrode assembly and the unipolar plate 100 are tightly attached to each other, thereby achieving the technical effect of improving the current density and the current intensity of the fuel cell.

It should be noted that: the number of the first protrusions 121 located at the central portion of the unipolar plate body 110 may be one or more, and in practical applications, the number may be adjusted according to the total length of the unipolar plate body 110 and the required pressing force. Specifically, when the overall length of the unipolar plate body 110 is small, the first protrusions 121 may be provided a little, and when the overall length of the unipolar plate body 110 is long, the first protrusions 121 need to be provided a little more; when the required pressing force is large, the first projecting portion 121 needs to be provided more, and when the required pressing force is small, the first projecting portion 121 needs to be provided less. The specific number of the first protrusions 121 is not limited herein.

It should be understood that: when the unipolar plate 100 includes the plurality of first protrusions 121, the heights H1 of the plurality of first protrusions 121 may be the same or different, and similarly, the heights H2 of the plurality of second protrusions 122 may be the same or different.

Preferably, as shown in fig. 2, the heights H1 of the plurality of first protrusions 121 are the same, and the heights H2 of the plurality of second protrusions 122 are also the same. With the above arrangement, the manufacturing can be facilitated.

The larger the height difference between the first protrusion 121 and the second protrusion 122 is, the larger the pressing force applied to the central portion of the unipolar plate 100 is, when the height difference between the first protrusion 121 and the second protrusion 122 is too large, the first protrusion 121 may be damaged, and when the height difference between the first protrusion 121 and the second protrusion 122 is too small, the pressing force applied to the central portion of the unipolar plate 100 is not large enough, so that the problem of insufficient pressing force in the prior art cannot be solved in a limited manner. Thus, in some embodiments of the present application, the difference in height between the first and

second protrusions

121 and 122 is 80 μm to 120 μm.

Preferably, the difference in height between the first and

second protrusions

121 and 122 is 100 μm.

Further, to improve the uniformity of the compressive force experienced by the entire unipolar plate 100, in some embodiments of the present application, the height of the bosses 120 gradually decreases in a direction from the central portion of the unipolar plate body 110 to the edge portion of the unipolar plate body 110, as shown in fig. 3.

Further, in some embodiments of the present application, the height of the lobes 120 gradually decreases in an equal difference manner in a direction from the center portion of the unipolar plate body 110 to the edge portion of the unipolar plate body 110. Specifically, the height difference between two adjacent convex portions 120 is 20 μm.

Further, the first flow-through space 200 formed by the protruding portion 120 is used for flowing cooling water, and the second flow-through space 300 formed by two adjacent protruding portions 120 is used for flowing an oxidizing agent or a reducing agent, so as to avoid the cross-sectional area of the first flow-through space 200 and the cross-sectional area of the second flow-through space 300 changing due to the height change of the protruding portion 120, and further cause the flow blockage phenomenon of the cooling water, the oxidizing agent or the reducing agent, in some embodiments of the present application, the cross-sectional area of the first protruding portion 121 is the same as the cross-sectional area of the second protruding portion 122. This is because when the flow rates of the cooling water, the oxidizing agent, or the reducing agent are the same, the flow rate of the cooling water, the oxidizing agent, or the reducing agent flowing through each of the protrusions 120 is proportional to the cross-sectional area of the protrusion 120, and in order to avoid the flow blockage phenomenon, the flow rate of the cooling water, the oxidizing agent, or the reducing agent flowing through each of the protrusions 120 needs to be the same, and therefore, the cross-sectional area of the first protrusion 121 and the cross-sectional area of the second protrusion 122 need to be the same.

Specifically, in some embodiments of the present application, as shown in fig. 2, the opening width L2 of the second protrusion 122 is greater than the opening width L1 of the first protrusion 121.

The opening width L1 of the first protrusion 121 and the opening width L2 of the second protrusion 122 refer to the distance between the first protrusion 121 and the second protrusion 122 and two joints of the unipolar plate body 110, respectively, along the arrangement direction of the protrusions 120.

Further, the height of the protrusion 120 gradually decreases in a direction from the center of the unipolar plate body 110 to the edge of the unipolar plate body 110, and the opening width of the protrusion 120 gradually increases in a direction from the center of the unipolar plate body 110 to the edge of the unipolar plate body 110.

Further, in order to improve the uniformity of the distribution of the first and second flow-through

spaces

200 and 300 on the unipolar plate 100, in some embodiments of the present application, the plurality of protrusions 120 are disposed at equal intervals. By arranging the plurality of protrusions 120 at equal intervals, the second flow space 300 formed between two adjacent protrusions 120 can be uniformly distributed on the unipolar plate 100, thereby achieving a technical effect of improving the uniformity of the flow of the oxidizing agent or the reducing agent flowing in the second flow space 300.

Further, as shown in fig. 4, the protruding portion 120 includes a first side edge 123, a second side edge 124 and a top edge 125, one end of the first side edge 123 and the second side edge 124 is fixedly connected to the unipolar plate body 110, the other end of the first side edge 123 and the second side edge 124 is fixedly connected to the top edge 125, and an included angle between the first side edge 123 and the second side edge 124 and the top edge 125 is not less than 90 °.

By providing the first side edge 123 and the second side edge 124 at an angle of no less than 90 degrees with respect to the top edge 125, the fabrication process of the unipolar plate 100 may be simplified. This is because the unipolar plate 100 is formed by stamping with a die, and by setting the included angle between the first side edge 123 and the second side edge 124 and the top edge 125 to be not less than 90 °, the die can be more easily removed from the stamped unipolar plate 100.

Further, in some embodiments of the present application, the top edge 125 is parallel to the unipolar plate body 110. Through the arrangement, the contact area between two adjacent unipolar plates 100 during stacking can be increased, the pressing force between two adjacent unipolar plates 100 can be increased, and the current density and the current intensity of the fuel cell can be further improved.

Further, in some embodiments of the present application, the first side edge 123 and the top edge 125, the second side edge 124 and the top edge 125, the first side edge 123 and the unipolar plate body 110, and the second side edge 124 and the unipolar plate body 110 are all transitioned through a chamfer or a fillet. With the above arrangement, the performance of the unipolar plate 100 may be prevented from being affected by damage to the protrusions 120 due to the impact of cooling water, an oxidizing agent, or a reducing agent.

It should be understood that the cross-section of the boss 120 may be rectangular or trapezoidal.

Preferably, the cross-sectional area of the boss 120 is an isosceles trapezoid. First, the second flow channel 400 formed on both sides of the protruding portion 120 having the isosceles trapezoid cross-sectional area has the same shape as the first flow channel 300 formed on the protruding portion 120, so that the uniformity of the force applied to both sides of the unipolar plate 100 can be improved; second, the two oblique sides of the protrusion 120 having the isosceles trapezoid cross-sectional area can be used as draft angles of a mold, which is convenient for manufacturing.

The bipolar plate 10 according to the present embodiment further includes, as shown in fig. 5, a bipolar plate 10 including a first unipolar plate 11 and a second unipolar plate 12 disposed opposite to the first unipolar plate 11, wherein the first unipolar plate 11, and/or the second unipolar plate 12 are unipolar plates 100 according to any of the embodiments described above.

It should be understood that: in one embodiment of the present application, the bipolar plate 10 includes a first unipolar plate 11 and a second unipolar plate 12, with either the first unipolar plate 11 or the second unipolar plate 12 being the unipolar plate 100 of any of the embodiments described above.

Preferably, the first unipolar plate 11 and the second unipolar plate 12 of the bipolar plate 10 are both unipolar plates 100 of any of the embodiments described above.

It should be noted that when only one of the first unipolar plate 11 and the second unipolar plate 12 in the bipolar plate 10 is the unipolar plate 100 in any of the above embodiments, the first unipolar plate 11 and the second unipolar plate 12 are the same in shape and size. Specifically, as shown in fig. 6, the first unipolar plate 11 and the second unipolar plate 12 are both rectangular, and the length and the width of the first unipolar plate 11 and the second unipolar plate 12 are both the same; only the lobes 120 on the first unipolar plate 11 and the lobes 120 on the second unipolar plate 12 are different in size.

The embodiment of the application also provides a fuel cell 1, and the fuel cell 1 comprises the unipolar plate 100 in any one of the embodiments.

To sum up, in the embodiment of the present application, the height of the at least one first protrusion 121 located at the center of the unipolar plate body 110 is greater than the height of the plurality of second protrusions 122 located at the edge of the unipolar plate body 110, so that when the plurality of unipolar plates 100 are pressed, the acting force between the center of two adjacent unipolar plates 100 is increased, and further the pressing force of the center of the unipolar plate 100 is increased, so that the membrane electrode assembly and the unipolar plate 100 are tightly attached to each other, thereby achieving the technical effect of improving the current density and the current intensity of the fuel cell; meanwhile, by setting the cross-sectional area of the first protrusion 121 to be the same as the cross-sectional area of the second protrusion 122, the flow blockage phenomenon is avoided, and the performance of the unipolar plate 100 is improved.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and parts that are not described in detail in a certain embodiment may refer to the above detailed descriptions of other embodiments, which are not described herein again. In specific implementation, each unit or structure may be implemented as an independent entity, or may be combined arbitrarily, and implemented as the same or several entities, which is not described herein again.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

The monopolar plate, the bipolar plate and the fuel cell provided by the embodiment of the present invention are described in detail, and the principle and the embodiment of the present invention are explained by applying specific examples, and the description of the embodiment is only used for helping to understand the structure and the core idea of the present invention; meanwhile, for those skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed, and in summary, the content of the present specification should not be construed as limiting the present invention.

Claims

1. A unipolar plate for forming a bipolar plate, the unipolar plate comprising: the cooling water pipe comprises a unipolar plate body and a plurality of convex parts which are convex towards one side of the unipolar plate body and form cooling water flow; the plurality of bosses comprise at least one first boss positioned at the central part of the unipolar plate body and a plurality of second bosses positioned at the edge part of the unipolar plate body;

2. The unipolar plate of claim 1, wherein the first and second raised portions have a height difference of 80-120 μ ι η.

3. The unipolar plate of claim 2, wherein the first and second lobes have a height difference of 100 μ ι η.

4. The unipolar plate of claim 1, wherein the raised portions progressively decrease in height in a direction from the central portion of the unipolar plate body to the edge portion of the unipolar plate body.

5. The unipolar plate of claim 1, wherein the cross-sectional area of the first boss is the same as the cross-sectional area of the second boss.

6. The unipolar plate of claim 5, wherein the second lobes have an opening width greater than an opening width of the first lobes.

7. The unipolar plate according to claim 4, wherein the projections have an opening width that gradually increases in a direction from a center portion of the unipolar plate body to an edge portion of the unipolar plate body.

8. The unipolar plate of claim 1, wherein the plurality of lobes are equally spaced.

9. The unipolar plate of claim 1, wherein the boss includes a first side, a second side, and a top side, one end of the first side and the second side being fixedly connected to the unipolar plate body, the other end of the first side and the second side being fixedly connected to the top side, the first side and the second side having an included angle of no less than 90 ° with the top side.

10. The unipolar plate of claim 9, wherein the first and top edges, the second and top edges, the first and unipolar plate bodies, the second and unipolar plate bodies are each transitioned between the first and top edges by a chamfer or fillet.

11. The unipolar plate of claim 1, wherein the lobes are rectangular or trapezoidal.

12. A bipolar plate comprising a first unipolar plate and a second unipolar plate disposed opposite said first unipolar plate, and/or said second unipolar plate being a unipolar plate according to any one of claims 1 to 11.

13. A fuel cell comprising a unipolar plate according to any one of claims 1 to 11.