Separator, single cell and fuel cell

Abstract

The present application proposes a partition, a single cell and a fuel cell; the partition includes a windward section, a peak section, a leeward section and a valley section connected in sequence; the peak section is concave toward one side in the thickness direction; the valley section is concave toward the other side in the thickness direction; the windward section is provided with a first opening for connecting the first groove and the second groove on both sides of the windward section; the leeward section is provided with a second opening for connecting the first groove and the second groove on both sides of the leeward section; the partition also includes a plurality of drainage sections; the first section of some windward sections is connected to a drainage section; the drainage section at least partially blocks the first opening on the windward section to which it is connected; the drainage sections all have a free end, and the free end is located in the second groove defined by the corresponding windward section; the drainage section extends from its free end toward the peak section connected to its corresponding windward section, so as to guide the airflow in the second groove to flow toward the peak section. The present application aims to solve the technical problem of uneven distribution of gas in the gas field in the prior art.

Description

Technical Field

[0001] The present application relates to the field of battery equipment, and in particular to separators, single cells and fuel cells. Background Art

[0002] A hydrogen fuel cell is a type of power generation device that converts the chemical energy contained in a fuel into electrical energy through an electrochemical reaction within a stack. Fuel cells are used not only to supply power for industrial, domestic, and automotive applications, but also to power small electronic devices such as portable devices. As a result, fuel cells are a highly efficient and clean energy source, and their application is steadily expanding.

[0003] A hydrogen fuel cell consists of a cathode plate, a gas diffusion layer, and an anode plate. A gas diffusion layer is placed between the cathode and anode plates; opposite sides of the gas diffusion layer contact the cathode and anode plates, respectively. The compression between the gas diffusion layer and the plates creates uneven pressure distribution within the gas field, which in turn causes uneven gas distribution within the field. Summary of the Invention

[0004] The main purpose of this application is to provide a separator, a single cell and a fuel cell, aiming to solve the technical problem of uneven distribution of gas in the gas field existing in the prior art.

[0005] The present application provides a separator for a single battery, wherein the separator has a length direction and a thickness direction;

[0006] The separator comprises a plurality of plate segments connected in sequence and extending along the length direction; each of the plate segments comprises a windward segment, a peak segment, a leeward segment, and a valley segment connected in sequence; wherein the peak segment is used to abut against the membrane electrode assembly of the single cell, and the valley segment is used to abut against the electrode plate of the single cell;

[0007] Each of the peak sections is recessed toward one side in the thickness direction, defining a first groove with the windward section and the leeward section connected thereto; each of the valley sections is recessed toward the other side in the thickness direction, defining a second groove with the windward section and the leeward section connected thereto;

[0008] Each of the windward sections is provided with a first opening, so that the first groove and the second groove on both sides of the windward section are connected; each of the leeward sections is provided with a second opening, so that the first groove and the second groove on both sides of the leeward section are connected; each of the windward sections has a first section located on one side of the first opening, and the first section is connected to the peak section;

[0009] In which, the partition also includes multiple diversion sections; the first section of at least a part of the windward section is connected to a diversion section; each of the diversion sections at least partially blocks the first opening on the windward section to which it is connected; each of the diversion sections has a free end, and the free end is located in the second groove defined by its corresponding windward section; each of the diversion sections extends from its free end toward the peak section connected to its corresponding windward section, so as to guide the airflow in the second groove to flow toward the peak section.

[0010] Optionally, a coordinate system is established with the length direction as the direction of the horizontal axis and the thickness direction as the direction of the vertical axis; in the coordinate system, the angle between the tangent of any point on the drainage section and the horizontal axis is a first angle; the angle between the tangent of any point on the windward section and the horizontal axis is a second angle; at the same horizontal coordinate position, the first angle is smaller than the second angle.

[0011] Optionally, the first angle gradually increases in an extension direction from the free end of the drainage section to a connection point between the drainage section and the first section.

[0012] Optionally, the partition further includes a width direction; each windward section has a plurality of first openings spaced apart along the width direction;

[0013] At least a portion of the first opening on each of the windward sections is partially blocked by the diversion section.

[0014] Optionally, on the same windward section, only one of the two adjacent first openings in the width direction is partially blocked by the drainage section.

[0015] Optionally, in two adjacent first openings in the width direction, the width of the first opening partially blocked by the drainage section is greater than the width of the first opening not partially blocked by the drainage section.

[0016] Optionally, the drainage segments connected to two adjacent windward segments in the length direction are staggered in the width direction.

[0017] Optionally, each leeward section has a plurality of second openings arranged at intervals along the width direction; wherein the second openings are arranged in a one-to-one correspondence with the first openings.

[0018] The present application also proposes a single battery, comprising:

[0019] membrane electrode assembly;

[0020] an electrode plate, the electrode plate being spaced apart from the membrane electrode assembly; and

[0021] The separator as described above; the separator is arranged between the membrane electrode assembly and the electrode plate.

[0022] The present application also provides an embodiment of a fuel cell, comprising a plurality of the above-mentioned single cells.

[0023] In an embodiment, after the separator is assembled to the membrane electrode assembly and the electrode plate, the first groove serves as the first channel for gas flow. The second groove serves as the second channel for gas flow. The first channel and the second channel are alternately arranged along the length direction. In the flow direction, the first channel and the second channel adjacent to the downstream thereof are connected through the second opening; the second channel and the first channel adjacent to the downstream thereof are connected through the first opening, thereby allowing the airflow to flow in the length direction. When the airflow flows into the second groove, a part of the airflow will be guided by the drainage section, forcing the airflow to flow toward the part where the separator and the membrane electrode assembly abut (i.e., the peak section), so as to improve the uniformity of gas distribution in the gas field when the pressure distribution in the gas field is uneven, thereby improving the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0025] Figure 1 A schematic structural diagram of a partition proposed in an embodiment of the present application;

[0026] Figure 2 A partial schematic diagram of a partition proposed in an embodiment of the present application in a coordinate system;

[0027] Figure 3 A partial schematic diagram of a partition proposed in an embodiment of the present application from one perspective;

[0028] Figure 4 Another partial schematic diagram of the partition proposed in an embodiment of the present application from one perspective;

[0029] Figure 5 A partial schematic diagram of a separator proposed in an embodiment of the present application used in a fuel cell;

[0030] Figure 6 This is another partial schematic diagram of the separator proposed in an embodiment of the present application being used in a fuel cell.

[0031] Reference Signs List

[0032]

[0033] DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0038] A fuel cell includes a membrane electrode assembly (MEA), a cathode plate, and an anode plate. The cathode and anode plates rest against the MEA, defining cathode and anode gas flow channels, respectively. Because the flow channel ridges of the cathode and anode plates rest against the MEA, localized high pressure is generated there, making it difficult for gas to diffuse toward the abutment points, resulting in uneven gas distribution. To address this issue, embodiments of the present application propose a separator to reduce this uneven gas distribution.

[0039] Reference Figure 1 As shown, the present application proposes a separator 100 having a length direction and a thickness direction. The separator 100 has a plurality of plate segments 110 connected in sequence and extending along the length direction. Each plate segment 110 includes a windward segment 111, a peak segment 112, a leeward segment 113, and a valley segment 114 connected in sequence. The peak segment 112 is used to abut the membrane electrode assembly 200 of the single cell, and the valley segment 114 is used to abut the electrode plate of the single cell. Each peak segment 112 is recessed toward one side in the thickness direction, defining a first groove S1 with the windward segment 111 and the leeward segment 113 connected thereto. Each valley segment 114 is recessed toward the other side in the thickness direction, defining a second groove S2 with the windward segment 111 and the leeward segment 113 connected thereto. In an embodiment, after the separator 100 is assembled to the membrane electrode assembly 200 and the electrode plate, the first groove S1 serves as a first channel S11 for gas flow. The second groove S2 serves as a second channel S21 for gas flow. The first channels S11 and the second channels S21 are alternately arranged along the length direction.

[0040] Each of the windward sections 111 is provided with a first opening 111a, so that the first groove S1 and the second groove S2 on both sides of the windward section 111 are connected; each of the leeward sections 113 is provided with a second opening 113a, so that the first groove S1 and the second groove S2 on both sides of the leeward section 113 are connected. That is, when the separator 100 is placed between the membrane electrode assembly 200 and the electrode plate, combined with FIG. Figure 5 As shown, in the flow direction, the first channel S11 and its adjacent downstream second channel S21 are connected through the second opening 113a; the second channel S21 and its adjacent downstream first channel S11 are connected through the first opening 111a, thereby allowing the airflow to flow in the length direction.

[0041] Each of the windward sections 111 has a first section 1111 located on one side of the first opening 111a, and the first section 1111 is connected to the peak section 112; wherein, the partition 100 also includes a plurality of diversion sections 115; the first section 1111 of at least a portion of the windward sections 111 is connected to a diversion section 115; each of the diversion sections 115 at least partially blocks the first opening 111a on the windward section 111 to which it is connected; each of the diversion sections 115 has a free end, and the free end is located in the second groove S2 defined by its corresponding windward section 111; each of the diversion sections 115 extends from its free end toward the peak section 112 connected to its corresponding windward section 111, so as to guide the airflow in the second groove S2 to flow toward the peak section 112. In the technical solution of the embodiment of the present application, after the air flow flows into the second groove S2, a part of the air flow will be guided by the diversion section 115, forcing the air flow to flow toward the part where the partition 100 and the membrane electrode assembly 200 abut (i.e., the peak section 112), so as to improve the uniformity of gas distribution in the gas field when the pressure distribution in the gas field is uneven, thereby improving the energy density of the battery.

[0042] It should be noted that, in the embodiment, the diversion section 115 is configured not to completely block the first opening 111 a , and the diversion section 115 plays a role of diversion and guides a portion of the airflow toward the peak section 112 .

[0043] It should be noted that, in the embodiment, the partition 100 has a plurality of plate segments 110, and the plate segments 110 are periodically arranged along the length direction. Each plate segment 110 includes a windward segment 111, a peak segment 112, a leeward segment 113, and a valley segment 114 connected in sequence. Between two adjacent plate segments 110, the valley segment 114 of one is connected to the windward segment 111 of the other. In the embodiment, the windward and leeward segments 113 can be straight or curved. The windward segment 111 can have a single slope or multiple slopes; the leeward segment 113 can have a single slope or multiple slopes.

[0044] It should be noted that the windward section 111 further includes a second section 1112 connected to the valley section 114. The first opening 111a is constructed between the first section 1111 and the second section 1112.

[0045] It should be noted that the membrane electrode assembly (MEA) consists of a proton exchange membrane, a gas diffusion layer, and a catalyst layer, and is the core component of fuel cells that generate electricity. The gas diffusion layer is a crucial component of the membrane electrode assembly in fuel cells. The MEA assembly is flanked by cathode and anode plates. The anode plate's flow holes and flow field provide hydrogen fuel to one side of the MEA assembly. The cathode plate's flow holes and flow field provide air as an oxidant to the other side of the MEA assembly. At the anode, hydrogen undergoes a catalytic reaction to produce protons (hydrogen ions) and electrons. The protons migrate through the proton exchange membrane to the cathode, while the electrons are drawn through the plates into an external circuit, where they flow through the external circuit to the cathode. At the cathode, oxygen in the air undergoes a catalytic reaction to produce electrons, forming negative ions. These ions react with the transferred protons to form water. Throughout this electrochemical reaction, the current drawn by the plates is the result of the fuel cell's electricity generation.

[0046] As an optional implementation of the above embodiment, a coordinate system is established with the length direction as the direction of the horizontal axis and the thickness direction as the direction of the vertical axis, such as Figure 2 As shown in the coordinate system, the angle between the tangent line at any point on the diversion section 115 and the abscissa axis is a first angle; the angle between the tangent line at any point on the windward section 111 and the abscissa axis is a second angle. At the same abscissa position, the first angle is smaller than the second angle. This arrangement allows airflow to be directed to the peak section 112 along the extension direction of the diversion section 115.

[0047] As an alternative embodiment to the above embodiment, the first angle gradually increases in the direction extending from the free end of the drainage section 115 to the connection between the drainage section 115 and the first section 1111. With this configuration, the inclination of the drainage section 115 gradually approaches that of the windward section 111, reducing the degree of eddy current in the airflow at the transition between the drainage section 115 and the windward section 111, thereby reducing pressure loss, allowing the airflow to be more smoothly guided to the membrane electrode assembly 200, and improving gas uniformity.

[0048] As an optional embodiment of the above embodiment, the separator 100 also includes a width direction. In the embodiment, each peak section 112 extends along the width direction, so the peak section 112 and the membrane electrode assembly 200 have a contact area extending along the width direction, and the contact area is a high-pressure area. Moreover, the second groove S2 (second channel S21) also extends along the width direction. To this end, in the embodiment, each windward section 111 has a plurality of first openings 111a spaced apart along the width direction; the plurality of first openings 111a are provided so that the airflow flows along the length direction. At least part of the first openings 111a on each of the windward sections 111 is partially blocked by the diversion section 115. With this arrangement, when the airflow enters the second groove S2, since at least part of the first openings 111a is partially blocked by the diversion section 115, at least part of the airflow will be guided to flow toward the high-pressure area, thereby reducing the degree of gas unevenness.

[0049] In this embodiment, all first openings 111a may be provided with a guide section 115. In this arrangement, the flow of air in the longitudinal direction may be blocked by the guide section 115 to a certain extent, and thus the required gas delivery pressure may be higher. Alternatively, only some first openings 111a may be provided with a guide section 115. In this arrangement, the required gas delivery pressure is relatively lower compared to the previous arrangement. In the specific implementation, the specific arrangement can be made according to actual circumstances.

[0050] As an optional implementation of the above embodiment, in order to allow the gas to flow more toward the membrane electrode assembly 200 while having sufficient fluidity in the flow direction to avoid gas shortage downstream, on the same windward section 111, only one of the two adjacent first openings 111a in the width direction is partially blocked by the diversion section 115. In this embodiment, the airflow has three main flow directions: one part is guided to the peak section 112 under the action of the diversion section 115; one part passes through the first opening 111a where the diversion section 115 is located and flows into the first groove S1; and another part, because the adjacent first opening 111a is not blocked by the diversion section 115, a part of the airflow flows around and passes through the first opening 111a blocked by the diversion section 115, thereby ensuring the fluidity of the gas and avoiding the occurrence of air suffocation and gas shortage.

[0051] As an alternative embodiment to the above embodiment, of the two adjacent first openings 111a in the width direction, the width of the first opening 111a partially obstructed by the drainage section 115 is smaller than the width of the first opening 111a not partially obstructed by the drainage section 115. In this embodiment, because the drainage section 115 has a certain gas intercepting effect, a portion of the airflow generates vortices there, affecting the fluidity of the gas. Therefore, this configuration reduces the pressure at the first opening 111a not obstructed by the drainage section 115, facilitating sufficient gas fluidity in the flow direction.

[0052] In some embodiments, the width of the first opening 111a partially blocked by the diversion section 115 may also be set to be larger than the width of the first opening 111a not partially blocked by the diversion section 115. This is mainly for the purpose of allowing more gas to diffuse toward the membrane electrode assembly 200. That is, under the premise of strong gas flow (for example, when the gas delivery pressure is high), by reducing the width of the first opening 111a not partially blocked by the diversion section 115, a certain pressure increase is caused there, forcing the airflow at the adjacent first opening 111a to diffuse more toward the membrane electrode assembly 200, while less of the airflow flows to the first opening 111a not partially blocked by the diversion section 115.

[0053] As an alternative embodiment to the above embodiment, the drainage sections 115 connecting two adjacent windward sections 111 in the longitudinal direction are staggered in the width direction. For example, two adjacent windward sections 111 have corresponding first openings 111a in the width direction, with the drainage section 115 being provided at the first opening 111a on one windward section 111 (on the upstream side), while the drainage section 115 is not provided at the first opening 111a on the other windward section 111 (on the downstream side). This arrangement primarily improves gas flow uniformity while also reducing gas flow resistance.

[0054] As an alternative embodiment to the above embodiment, each leeward section 113 has a plurality of second openings 113a spaced apart along the width direction. The second openings 113a are disposed in a one-to-one correspondence with the first openings 111a. In this embodiment, the one-to-one correspondence between the first openings 111a and the second openings 113a is provided to reduce flow resistance of the gas in the flow direction.

[0055] The present application also proposes a single cell, comprising a membrane electrode assembly 200, a plate and a separator 100. The plate is spaced apart from the membrane electrode assembly 200. Figure 5As shown, the separator 100 is arranged between the membrane electrode assembly 200 and the electrode plate. The separator 100 adopts part or all of the technical solutions in the above embodiments. In a specific embodiment, two separators 100 can be placed in a single cell. Among them, the electrode plate includes a cathode plate 400 and an anode plate 300. Figure 6 As shown, one of the two separators 100 is placed between the cathode plate 400 and the membrane electrode assembly 200, and the other is placed between the anode plate 300 and the membrane electrode assembly 200. In a single cell, one separator 100 may also be placed, and the separator 100 may be placed between the cathode plate 400 and the membrane electrode assembly 200 or between the anode plate 300 and the membrane electrode assembly 200.

[0056] In the embodiment, after the separator 100 is assembled to the membrane electrode assembly 200 and the electrode plate, the first groove S1 serves as a first channel S11 for gas flow. The second groove S2 serves as a second channel S21 for gas flow. The first channels S11 and the second channels S21 are arranged alternately along the length. The first channels S11 and the second channels S21 are connected through the first opening 111a and the second opening 113a, allowing gas flow in the length direction.

[0057] This application also provides an embodiment of a fuel cell comprising multiple single cells. The multiple single cells are stacked along the thickness direction to form a fuel cell stack. The single cell comprises a membrane electrode assembly (MEA) 200, electrode plates, and a separator 100. The electrode plates are spaced apart from the MEA 200. The separator 100 is disposed between the MEA 200 and the electrode plates. The separator 100 utilizes some or all of the technical solutions described in the previous embodiments. In a specific embodiment, two separators 100 may be placed in a single cell. The electrode plates include a cathode plate 400 and an anode plate 300. One of the two separators 100 is placed between the cathode plate 400 and the MEA 200, and the other is placed between the anode plate 300 and the MEA 200. Of course, a single separator 100 may also be placed in a single cell, either between the cathode plate 400 and the MEA 200 or between the anode plate 300 and the MEA 200.

[0058] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structural transformation made by using the contents of the present application specification and drawings under the application concept of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A separator for a single battery, characterized in that: The partition has a length direction and a thickness direction; The separator has a plurality of plate segments connected in sequence along the length direction; each of the plate segments includes a windward segment, a peak segment, a leeward segment, and a valley segment connected in sequence; wherein the peak segment is used to abut against the membrane electrode assembly of the single cell, and the valley segment is used to abut against the electrode plate of the single cell; Each of the peak sections is recessed toward one side in the thickness direction, defining a first groove with the windward section and the leeward section connected thereto; each of the valley sections is recessed toward the other side in the thickness direction, defining a second groove with the windward section and the leeward section connected thereto; Each of the windward sections is provided with a first opening, so that the first groove and the second groove on both sides of the windward section are connected; each of the leeward sections is provided with a second opening, so that the first groove and the second groove on both sides of the leeward section are connected; each of the windward sections has a first section located on one side of the first opening, and the first section is connected to the peak section; In which, the partition also includes multiple diversion sections; the first section of at least a part of the windward section is connected to a diversion section; each of the diversion sections at least partially blocks the first opening on the windward section to which it is connected; each of the diversion sections has a free end, and the free end is located in the second groove defined by its corresponding windward section; each of the diversion sections extends from its free end toward the peak section connected to its corresponding windward section to guide the airflow in the second groove toward the peak section.

2. The separator according to claim 1, wherein A coordinate system is established with the length direction as the direction of the horizontal axis and the thickness direction as the direction of the vertical axis. In the coordinate system, the angle between the tangent line of any point on the drainage section and the horizontal axis is a first angle, and the angle between the tangent line of any point on the windward section and the horizontal axis is a second angle. At the same horizontal coordinate position, the first angle is smaller than the second angle.

3. The separator according to claim 2, wherein In the extending direction from the free end of the drainage section to the connection between the drainage section and the first section, the first angle gradually increases.

4. The separator according to claim 1, wherein The partition further includes a width direction, and each windward section has a plurality of first openings spaced apart along the width direction; At least a portion of the first opening on each of the windward sections is partially blocked by the diversion section.

5. The separator according to claim 4, wherein On the same windward section, only one of the two first openings adjacent to each other in the width direction is partially blocked by the drainage section.

6. The separator according to claim 5, wherein Of the two first openings adjacent to each other in the width direction, the width of the first opening partially blocked by the drainage section is smaller than the width of the first opening not partially blocked by the drainage section.

7. The separator according to claim 4, wherein The drainage segments connected to two adjacent windward segments in the length direction are staggered in the width direction.

8. The separator according to claim 4, wherein Each of the leeward sections has a plurality of second openings spaced apart along the width direction; wherein the second openings are arranged in a one-to-one correspondence with the first openings.

9. A single cell battery, characterized in that: include: membrane electrode assembly; an electrode plate, the electrode plate being spaced apart from the membrane electrode assembly; as well as The separator according to any one of claims 1 to 8; The separator is disposed between the membrane electrode assembly and the electrode plate.

10. A fuel cell, characterized in that: The method comprises a plurality of single cells according to claim 9.

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