Polar plate and fuel cell

Abstract

The application provides a polar plate and a fuel cell, the polar plate comprising a gas inlet area, a flow field reaction area and a gas outlet area, the gas inlet area being communicated with the gas outlet area through the flow field reaction area. The flow field reaction area comprises a plurality of flow field reaction channels, each flow field reaction channel comprising a plurality of reaction units, each reaction unit comprising a first channel, a second channel and a merging channel, the merging channel merging the substances flowed from the first channel and the second channel. Since the first channel, the second channel and the merging channel of the flow field reaction area of the polar plate are integrally formed into a two-in-one flow channel structure, the two-in-one flow channel structure can convert the laminar flow into the turbulent flow, and then make the fuel gas diffuse to the proton exchange membrane at the merging channel, thereby enhancing the electrochemical reaction, reducing the accumulation of liquid water in the flow channel, and then relieving the "water flooding" phenomenon, enhancing the mass transfer and heat exchange capacity, so that the fuel cell of the application has better performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a polar plate and a fuel cell. BACKGROUND

[0002] The water management problem of the fuel cell has a great influence on the performance of the fuel cell. When the water content in the fuel cell is insufficient, the proton exchange membrane is in a dehydrated state, which makes the proton conductivity of the membrane decrease sharply, seriously affecting the normal work of the fuel cell. When the water content in the fuel cell is too high, the "waterlogging" phenomenon is easy to occur, and the gas flow channel, gas diffusion layer and even the catalyst layer are submerged by water, which causes the reactant gas to be unable to reach the reaction site to participate in the reaction, causing the performance of the fuel cell to deteriorate sharply.

[0003] Reasonable design of the flow channel of the polar plate of the fuel cell can effectively improve the flow field distribution of the reactant gas and reduce the liquid in the flow channel. At present, the technology for preventing waterlogging mainly focuses on the flow channel structure of the polar plate. Common flow channel structures include serpentine flow channel, interdigital flow channel and various bionics flow channels. These flow channel structures cannot well solve the "waterlogging" problem. SUMMARY

[0004] In order to solve the above problems, the present application provides a polar plate and a fuel cell.

[0005] In a first aspect, the polar plate of the present application comprises a gas inlet area, a flow field reaction area and a gas outlet area, the gas inlet area is communicated with the gas outlet area through the flow field reaction area. Wherein, the flow field reaction area comprises a plurality of flow field reaction channels, and the plurality of flow field reaction channels are arranged at intervals. Each flow field reaction channel comprises a plurality of reaction units, each reaction unit comprises a first channel, a second channel and a merging channel, the merging channel is communicated with the first channel and the second channel and merges the substances flowing from the first channel and the second channel. The gas inlet area and the gas outlet area are respectively communicated with the first channel and the second channel of the corresponding reaction unit of each flow field reaction channel.

[0006] Further, the plurality of reaction units of each flow field reaction channel comprises a first reaction unit, a second reaction unit and a third reaction unit. The first reaction unit is arranged close to the gas inlet area, the third reaction unit is arranged close to the gas outlet area, and the second reaction unit is arranged between the first reaction unit and the third reaction unit.

[0007] Further, the second reaction unit of each flow field reaction channel is multiple in number, and the lengths of the plurality of second reaction units increase in turn.

[0008] Further, the first channel of each reaction unit comprises a straight section and an inclined section, and the straight section is connected to the inclined section.

[0009] Further, the inclined section of the first channel of the first reaction unit and the third reaction unit is one section, the flat section of the first reaction unit is close to the gas inlet area, and the flat section of the third reaction unit is close to the gas outlet area. The inclined section of the first channel of the second reaction unit is two sections, the flat section of the second reaction unit is located between the two inclined sections and connected to the two inclined sections, and the inclined section of the second reaction unit is connected to the converging channel of the adjacent reaction unit.

[0010] Further, the second channel is identical in structure to the first channel.

[0011] Further, the plurality of flow field reaction channels comprises a first flow field reaction channel and a second flow field reaction channel, and the second flow field reaction channel is arranged opposite to or staggered with the first flow field reaction channel.

[0012] Further, the polar plate further comprises a first distribution area located between the gas inlet area and the flow field reaction area, for distributing the fuel flowing through the gas inlet area into the corresponding flow field reaction channel of the flow field reaction area.

[0013] Further, the polar plate further comprises a second distribution area located between the flow field reaction area and the gas outlet area, for distributing the fuel flowing through the flow field reaction area into the corresponding gas outlet of the gas outlet area.

[0014] In a second aspect, the fuel cell of the present application comprises an anode plate, a membrane electrode and a cathode plate which are stacked, wherein at least one of the anode plate and the cathode plate is the polar plate described above.

[0015] The present application has the following beneficial effects:

[0016] Since the first channel, the second channel and the converging channel of the flow field reaction area of the polar plate are integrally formed into a two-in-one flow channel structure, the laminar flow form can be converted into the turbulent flow form, and the fuel gas is diffused onto the proton exchange membrane at the converging channel, thereby enhancing the electrochemical reaction and improving the electrochemical performance of the fuel cell. At the same time, based on the two-in-one flow channel structure, the flow rate of the liquid water is also significantly improved, thereby reducing the accumulation of liquid water in the flow channel, thereby alleviating the “water flooding” phenomenon, strengthening the mass transfer and heat exchange capacity, and thus the fuel cell of the present application has better performance.

[0017] The summary section is provided to introduce a selection of concepts, in a simplified form, that are further described below in the detailed description. This summary is not intended to identify key or essential features of the disclosure, nor is it intended to limit the scope of the disclosure. Attached Figure Description

[0018] The above and other objects, features and advantages of this disclosure will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.

[0019] Figure 1 A schematic diagram of the electrode plate of the present invention is shown;

[0020] Figure 2 It shows Figure 1 A schematic diagram of the flow field reaction zone in one embodiment;

[0021] Figure 3 It shows Figure 1 A schematic diagram of the flow field reaction zone in another embodiment;

[0022] Figure 4 A partial structural schematic diagram of the flow field reaction channel in the flow field reaction zone is shown.

[0023] The reference numerals in the attached figures are explained as follows:

[0024] 100. Plate; 1. Inlet area; 2. Flow field reaction area; 21. Flow field reaction channel; 211. First channel; 2111. Straight section; 2112. Inclined section; 212. Second channel; 213. Merging channel; 3. Outlet area; 4. First distribution area; 5. Second distribution area. Detailed Implementation

[0025] Embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0026] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0027] The fuel cell of the present application comprises an anode plate, a membrane electrode (with proton exchange function, hereinafter referred to as proton exchange membrane) and a cathode plate which are stacked, and at least one of the anode plate and the cathode plate adopts the polar plate 100 described hereinafter.

[0028] Since the fuel cell of the present application adopts the polar plate 100 described hereinafter, it improves the efficiency of the diffusion of the gas to the proton exchange membrane, enhances the electrochemical reaction in the fuel cell, and further improves the electrochemical performance of the fuel cell; at the same time, it improves the flow rate of the liquid water, reduces the accumulation of the liquid water in the flow channel, and further relieves the "waterlogging" phenomenon, enhances the mass transfer and heat exchange capacity, so that the fuel cell of the present application has better performance.

[0029] Specifically, the fuel cell of the present application can be a hydrogen-air fuel cell or a hydrogen-oxygen fuel cell.

[0030] Reference Figures 1 to 4 The polar plate 100 of the present application comprises a gas inlet area 1, a flow field reaction area 2 and a gas outlet area 3, and the gas inlet area 1 communicates with the gas outlet area 3 through the flow field reaction area 2. Specifically, the polar plate 100 of the present application can be made of graphite material or metal.

[0031] Reference Figures 2 to 4 The flow field reaction area 2 comprises a plurality of flow field reaction channels 21 which are arranged at intervals. Each flow field reaction channel 21 comprises a plurality of reaction units, each reaction unit comprising a first channel 211, a second channel 212 and a merging channel 213, the merging channel 213 communicating with the first channel 211 and the second channel 212 and merging the substances flowing from the first channel 211 and the second channel 212. The gas inlet area 1 and the gas outlet area 3 respectively communicate with the first channel 211 and the second channel 212 of the corresponding reaction unit of each flow field reaction channel 21 to realize the entry and exit of the fuel gas in the polar plate 100.

[0032] Since the first channel 211, the second channel 212 and the merging channel 213 of the flow field reaction area 2 are integrally formed into a two-in-one flow channel structure, they can convert the laminar flow into turbulent flow, and further make the fuel gas diffuse to the proton exchange membrane at the merging channel 213, thereby enhancing the electrochemical reaction and further improving the electrochemical performance of the fuel cell; at the same time, based on the two-in-one flow channel structure, the flow rate of the liquid water is also significantly improved, thereby reducing the accumulation of the liquid water in the flow channel, further relieving the "waterlogging" phenomenon, enhancing the mass transfer and heat exchange capacity, so that the fuel cell of the present application has better performance. In addition, the structure of the polar plate 100 is simple, which reduces the processing difficulty and processing cost, and has higher feasibility.

[0033] Reference Figure 2 and Figure 3, the flow field reaction channel 21 includes a plurality of reaction units, and according to the positions of the reaction units, the plurality of reaction units include a first reaction unit, a second reaction unit and a third reaction unit. The first reaction unit is arranged close to the gas inlet area 1 (i.e., the first reaction unit is located at the leftmost side of the flow field reaction area 2), the third reaction unit is arranged close to the gas outlet area 3 (i.e., the third reaction unit is located at the rightmost side of the flow field reaction area 2), and the second reaction unit is located between the first reaction unit and the third reaction unit. Figure 3 Figure 3

[0034] In some embodiments, referring to Figure 3 , the second reaction unit is multiple in number, and the lengths of the plurality of second reaction units are sequentially increased (i.e., L4>L3>L2>L1), thereby improving the concentration gradient of the fuel gas in each flow field reaction channel 21 of the flow field reaction area 2, making the concentration distribution of the fuel gas more uniform, thereby further enhancing the electrochemical reaction and improving the electrochemical performance of the fuel cell.

[0035] Referring to Figure 3 and Figure 4 , the first channel 211 of each reaction unit includes a straight section 2111 and an inclined section 2112, and the straight section 2111 is connected to the inclined section 2112. Specifically, the inclined section 2112 of the first channel 211 of the first reaction unit and the third reaction unit is one section, the straight section 2111 of the first reaction unit is arranged close to the gas inlet area 1, and the straight section 2111 of the third reaction unit is arranged close to the gas outlet area 3. The inclined section 2112 of the first channel 211 of the second reaction unit is two sections, the straight section 2111 of the second reaction unit is located between the two inclined sections 2112 and connected to the two inclined sections 2112, and the inclined section 2112 of the second reaction unit is connected to the merging channel 213 of the adjacent reaction unit.

[0036] In this way, each flow field reaction channel 21 is actually a continuous channel formed by a plurality of two-in-one flow channel structures, thereby enabling the fuel gas to diffuse to the corresponding part of the proton exchange membrane at the corresponding merging channel 213, thereby enhancing the electrochemical reaction, alleviating the "flooding" phenomenon, and enhancing the mass transfer and heat exchange capacity.

[0037] Referring to Figure 4 ​​, the acute angle formed by the straight section 2111 and the inclined section 2112 of the first channel 211 of each reaction unit is A, and the angle size of A directly affects the performance of the polar plate 100, for example, the diffusion speed of the fuel gas to the proton exchange membrane can be increased by increasing the angle size of A; the increase range of the flow rate of each flow field reaction channel 21 of the flow field reaction area 2 can be controlled by changing the angle size of A; the gas flow resistance of each flow field reaction channel 21 of the flow field reaction area 2 can be controlled by changing the angle size of A, so the angle size of A can be selectively determined according to actual needs.

[0038] The smaller the angle of A, the relatively smaller the flow resistance, and the larger the angle of A, the relatively larger the flow resistance; and the larger the angle of A, the better the gas diffusion performance, so in order to balance the influence of flow resistance and gas diffusion performance to achieve the best effect, preferably, the angle size of A is in the range of 30°-50°.

[0039] Referring to Figure 3 and Figure 4 , the second channel 212 of each reaction unit is the same in structure as the first channel 211.

[0040] Referring to Figure 2 , the plurality of flow field reaction channels 21 include a first flow field reaction channel 21A and a second flow field reaction channel 21B, the second flow field reaction channel 21B is arranged opposite to the first flow field reaction channel 21A (i.e. the first channel 211, the second channel 212 and the merging channel 213 of the second flow field reaction channel 21B are arranged corresponding to the first channel 211, the second channel 212 and the merging channel 213 of the first flow field reaction channel 21A) or staggered (i.e. the merging channel 213 of the second flow field reaction channel 21B is arranged facing the first channel 211 or the second channel 212 of the first flow field reaction channel 21A).

[0041] Referring to Figure 1 , the polar plate 100 further includes a first distribution area 4, the first distribution area 4 is located between the gas inlet area 1 and the flow field reaction area 2, and is used for uniformly distributing the fuel flowing through the gas inlet area 1 to the corresponding flow field reaction channel 21 of the flow field reaction area 2.

[0042] Referring to Figure 1 , the polar plate 100 further includes a second distribution area 5, the second distribution area 5 is located between the flow field reaction area 2 and the gas outlet area 3, and is used for uniformly distributing the fuel flowing through the flow field reaction area 2 to the corresponding gas outlet of the gas outlet area 3.

[0043] Having described above several embodiments of the disclosure, any modifications and variations that fall within the scope of the described embodiments are also contemplated by the inventor(s). As such, the foregoing description is not intended to limit the scope of the disclosure, and it is recognized that modifications can be made by one of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The word "comprising" is used herein to mean "including" but not necessarily "consisting of" or "composed of." The word "comprising" therefore should not be interpreted as being limited to the recited items information.

Claims

1. An electrode plate, the electrode plate comprising an inlet region (1), a flow field reaction region (2), and an outlet region (3), wherein the inlet region (1) is connected to the outlet region (3) through the flow field reaction region (2), characterized in that, The flow field reaction zone (2) includes multiple flow field reaction channels (21), which are spaced apart. Each flow field reaction channel (21) includes multiple reaction units. Each reaction unit includes a first channel (211), a second channel (212), and a confluence channel (213). The confluence channel (213) connects the first channel (211) and the second channel (212) and merges the substances flowing from the first channel (211) and the second channel (212). The air inlet area (1) and the air outlet area (3) are respectively connected to the first channel (211) and the second channel (212) of the corresponding reaction unit of each flow field reaction channel (21); Each flow field reaction channel (21) includes multiple reaction units, including a first reaction unit, a second reaction unit, and a third reaction unit; The first reaction unit is located near the air inlet area (1); The third reaction unit is located near the gas outlet area (3); The second reaction unit is disposed between the first reaction unit and the third reaction unit; Each flow field reaction channel (21) has multiple second reaction units, and the lengths of the multiple second reaction units increase sequentially.

2. The electrode plate according to claim 1, characterized in that, The first channel (211) of each reaction unit includes a straight section (2111) and an inclined section (2112), wherein the straight section (2111) is connected to the inclined section (2112).

3. The electrode plate according to claim 2, characterized in that, The inclined section (2112) of the first channel (211) of the first reaction unit and the third reaction unit is one section, the straight section (2111) of the first reaction unit is close to the air inlet area (1), and the straight section (2111) of the third reaction unit is close to the air outlet area (3). The first channel (211) of the second reaction unit has two inclined sections (2112). The straight section (2111) of the second reaction unit is located between the two inclined sections (2112) and connected to the two inclined sections (2112). The inclined section (2112) of the second reaction unit is connected to the confluence channel (213) of the adjacent reaction unit.

4. The electrode plate according to claim 1, characterized in that, The second channel (212) is structurally identical to the first channel (211).

5. An electrode plate according to claim 1, characterized in that, The plurality of flow field reaction channels (21) include a first flow field reaction channel (21A) and a second flow field reaction channel (21B), wherein the second flow field reaction channel (21B) is arranged opposite to or offset from the first flow field reaction channel (21A).

6. The electrode plate according to claim 1, characterized in that, The electrode plate also includes a first distribution area (4), which is located between the air inlet area (1) and the flow field reaction area (2) and is used to distribute the fuel flowing through the air inlet area (1) into the corresponding flow field reaction channel (21) of the flow field reaction area (2).

7. The electrode plate according to claim 1, characterized in that, The electrode plate also includes a second distribution area (5), which is located between the flow field reaction area (2) and the outlet area (3) and is used to distribute the fuel flowing through the flow field reaction area (2) to the corresponding outlet of the outlet area (3).

8. A fuel cell, comprising a stacked anode plate, a membrane electrode assembly, and a cathode plate, characterized in that, At least one of the anode plate and the cathode plate is the electrode plate described in any one of claims 1-7.

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