Monopolar plate, bipolar plate and fuel cell

Abstract

The utility model provides a unipolar plate, a bipolar plate and a fuel cell. One side of the monopolar plate is provided with a flow field reaction area, a public pipeline area and a sealing area surrounding the flow field reaction area and the public pipeline area, the public pipeline area is provided with a reactant inlet, the flow field reaction area is provided with a plurality of flow channels communicated with the reactant inlet, and each flow channel extends in the longitudinal direction and is separated from the adjacent flow channel in the transverse direction. Wherein a peripheral flow channel is included adjacent to the sealing region and is defined by a plurality of ridges such that each ridge is located between two flow channels, and wherein the sealing region is provided with a bypass channel communicating the reactant inlet with the peripheral flow channel and each of the plurality of ridges arranged consecutively from the peripheral flow channel constituting a communicating ridge, each communicating ridge is provided with a notch allowing the two flow channels on the two sides to communicate with each other. The bipolar plate includes the monopolar plate, and the fuel cell includes the monopolar plate.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of fuel cells, and more particularly, to a single-pole plate with an improved flow channel design, a bipolar plate at least partially composed of the single-pole plate, and a fuel cell comprising the single-pole plate. BACKGROUND

[0002] Fuel cells have developed into one of the main power generation technologies due to their high power generation efficiency, low environmental pollution, high specific energy and other advantages. As a typical fuel cell, a proton exchange membrane fuel cell (PEMFC) is a popular fuel cell for vehicles. A PEMFC generally includes a solid polymer electrolyte proton-conducting membrane, such as a perfluorinated sulfonic acid membrane. The anode and the cathode generally include finely divided catalyst particles, usually platinum (Pt), supported on carbon particles and mixed with ionomer. The catalyst mixture is deposited on opposite sides of the membrane. The combination of the anode catalyst mixture, the cathode catalyst mixture, and the membrane defines a membrane electrode assembly (MEA).

[0003] The fuel cell stack includes a plurality of single cells combined together, each single cell including a membrane electrode assembly and anode and cathode plates located on both sides of the membrane electrode assembly, wherein the anode plate is provided with a flow field reaction zone for the flow of anode gas, which allows the anode gas to be supplied to the membrane electrode assembly, and the cathode plate is provided with a flow field reaction zone for the flow of cathode gas, which allows the cathode gas to be supplied to the membrane electrode assembly.

[0004] However, the current density in the single cell decreases as the cathode gas and the anode gas are consumed, that is, the current density in the downstream portion of the flow field reaction zone tends to be lower than that in the upstream portion, which limits the power level and working efficiency of the single cell and even the entire fuel cell.

[0005] In order to solve the above-mentioned problems in the prior art, there is an urgent need in the art for a technical solution that can effectively increase the concentration of reactants in the downstream portion of the flow field reaction zone so as to increase the current density. SUMMARY

[0006] To solve the above problems in the prior art, the present disclosure proposes an improved single-pole plate for a fuel cell, which is provided with a flow field reaction zone, a common duct zone and a sealing zone surrounding the flow field reaction zone and the common duct zone on one side, wherein the common duct zone is provided with a reactant inlet, wherein the flow field reaction zone is provided with a plurality of flow channels in communication with the reactant inlet, each flow channel extending along a longitudinal direction and being spaced apart from an adjacent flow channel along a transverse direction, the plurality of flow channels including a peripheral flow channel adjacent to the sealing zone and being defined by a plurality of ridges, such that each ridge is located between two flow channels, and wherein the sealing zone is provided with a bypass channel having an upstream end opening to the reactant inlet and a downstream end opening to the peripheral flow channel, and each of a plurality of ridges arranged consecutively from the peripheral flow channel constitutes a communication ridge, each communication ridge being provided with a notch allowing two flow channels on both sides thereof to communicate with each other.

[0007] According to an optional embodiment of the present disclosure, the sealing zone is provided with one bypass channel, and each ridge constitutes a communication ridge.

[0008] According to an optional embodiment of the present disclosure, the sealing zone is provided with two bypass channels, the plurality of flow channels includes two peripheral flow channels adjacent to the sealing zone, the upstream ends of the two bypass channels both open to the reactant inlet, and the downstream ends of the two bypass channels respectively open to the two peripheral flow channels.

[0009] According to an optional embodiment of the present disclosure, a plurality of ridges arranged consecutively from the two peripheral flow channels constitute two groups of communication ridges, and there is a partition ridge between the two groups of communication ridges, the partition ridge isolating two flow channels on both sides thereof from each other.

[0010] According to an optional embodiment of the present disclosure, the partition ridge is located at a middle position of the flow field reaction zone along the transverse direction.

[0011] According to an optional embodiment of the present disclosure, the downstream end of the bypass channel is positioned at a middle position of the peripheral flow channel along the longitudinal direction.

[0012] According to an optional embodiment of the present disclosure, a portion of the bypass channel between the upstream end and the downstream end is sealingly isolated from the flow field reaction zone and the common duct zone.

[0013] According to an optional embodiment of the present disclosure, the notch of each communication ridge is aligned with the downstream end of the bypass channel along the transverse direction.

[0014] According to an optional embodiment of the present disclosure, a flow guide block is arranged in each of the notches of the communication ridges, which divides the notch into an upstream portion and a downstream portion located on two sides of the notch, and the upstream portion is aligned with the downstream end of the bypass channel along the transverse direction.

[0015] According to an optional embodiment of the present disclosure, the transverse dimension of the flow guide block close to the peripheral flow passage is greater than the transverse dimension of the flow guide block away from the peripheral flow passage.

[0016] According to an optional embodiment of the present disclosure, the bottom of the notch of each communication ridge is higher than the bottom of the flow passage.

[0017] According to an optional embodiment of the present disclosure, the bottom of the notch of each communication ridge is flush with the bottom of the flow passage, and the notch of each communication ridge is aligned with the downstream end of the bypass channel along the transverse direction to form a distribution channel extending along the transverse direction in the flow field reaction zone.

[0018] According to an optional embodiment of the present disclosure, a flow guide strip is arranged in the distribution channel, which extends from the downstream end of the bypass channel along the transverse direction and divides the distribution channel into an upstream section and a downstream section located on two sides of the distribution channel and in communication with each other, and the upstream section is aligned with the downstream end of the bypass channel along the transverse direction.

[0019] According to an optional embodiment of the present disclosure, a plurality of flow disturbance blocks are arranged in the distribution channel and separated from each other.

[0020] Also to solve the above-mentioned problems in the prior art, the present disclosure further provides an improved bipolar plate for a fuel cell, which comprises: an anode plate; and a cathode plate combined with the anode plate, wherein at least one of the anode plate and the cathode plate is composed of the monopolar plate according to the present disclosure.

[0021] Also to solve the above-mentioned problems in the prior art, the present disclosure further provides an improved fuel cell, which comprises: a housing; and a stack accommodated in the housing, wherein the stack comprises a plurality of membrane electrode assemblies and a plurality of bipolar plates stacked together in an alternating manner, wherein each membrane electrode assembly is located between two bipolar plates, and wherein at least one bipolar plate is composed of the bipolar plate according to the present disclosure.

[0022] Also to solve the above problems in the prior art, the present disclosure further proposes an improved fuel cell, comprising: a housing; and an electric pile accommodated in the housing, wherein the electric pile comprises a plurality of single cells combined together, each single cell comprising a membrane electrode assembly and an anode plate and a cathode plate located on both sides of the membrane electrode assembly, and wherein at least one of the anode plate and the cathode plate is composed of the single pole plate of the present disclosure.

[0023] The present disclosure can be embodied as the illustrative embodiments in the accompanying drawings. However, it should be noted that the accompanying drawings are merely illustrative, and any variations envisaged under the teachings of the present disclosure should be considered to be included within the scope of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings illustrate exemplary embodiments of the present disclosure. These drawings should not be construed as necessarily limiting the scope of the present disclosure, wherein:

[0025] Figure 1 is a schematic perspective view of a fuel cell according to the present disclosure;

[0026] Figure 2 is a schematic front view of a single pole plate according to an embodiment of the present disclosure;

[0027] Figure 3 is a schematic cross-sectional view of the single pole plate taken along line III-III in Figure 2

[0028] Figure 4 is a schematic cross-sectional view of the single pole plate taken along line IV-IV in Figure 2

[0029] Figure 5 is a schematic front view of a single pole plate according to another embodiment of the present disclosure;

[0030] Figure 6 is a schematic cross-sectional view of the single pole plate taken along line VI-VI in Figure 5

[0031] Figure 7 is a schematic cross-sectional view of the single pole plate taken along line VII-VII in Figure 5

[0032] Figure 8 is a schematic front view of a single pole plate according to another embodiment of the present disclosure;

[0033] Figure 9 is a schematic front view of a single pole plate according to another embodiment of the present disclosure;

[0034] Figure 10 ​​​​is a schematic front view of a bipolar plate according to another embodiment of the present disclosure;

[0035] Figure 11 is a schematic front view of a bipolar plate according to another embodiment of the present disclosure;

[0036] Figure 12 is a schematic cross-sectional view of the bipolar plate taken along line XII-XII in Figure 11

[0037] Figure 13 is a schematic cross-sectional view of the bipolar plate taken along line XIII-XIII in Figure 11

[0038] Figure 14 is a schematic front view of a bipolar plate according to another embodiment of the present disclosure;

[0039] Figure 15 is a schematic cross-sectional view of the bipolar plate taken along line XV-XV in Figure 14

[0040] Figure 16 is a schematic cross-sectional view of the bipolar plate taken along line XVI-XVI in Figure 14 DETAILED DESCRIPTION

[0041] Further features and advantages of the present disclosure will become more apparent from the following description with reference to the accompanying drawings. In the drawings, exemplary embodiments of the present disclosure are illustrated and the individual drawings are not necessarily drawn to scale. However, the present disclosure can be embodied in many different forms and should not be construed as necessarily being limited to the exemplary embodiments of the disclosure set forth herein. Rather, these exemplary embodiments are merely provided for illustrative purposes to explain the present disclosure and to convey the spirit and essence of the present disclosure to one skilled in the art.

[0042] The present disclosure aims to propose a single pole plate having a novel flow channel design, a bipolar plate at least partially composed of the single pole plate, and a fuel cell including the single pole plate, which can significantly increase the reactant concentration in the downstream portion of the flow field reaction zone due to its novel flow channel design, and thereby increase the current density in the downstream portion of the flow field reaction zone, thereby improving the power level of the fuel cell. Accordingly, by using the single pole plate or the bipolar plate composed of the single pole plate, the power level and operating efficiency of the fuel cell can be significantly improved, and the service life and reliability thereof can also be significantly improved.

[0043] Optional but non-limiting embodiments of the single pole plate, the bipolar plate, and the fuel cell according to the present disclosure will be described in detail below with reference to the accompanying drawings.

[0044] ​​​​Reference Figure 1 wherein a schematic perspective view of a fuel cell according to the present disclosure is shown. As Figure 1 shown, the fuel cell 10 is a proton exchange membrane type fuel cell, which includes a housing 20 and an electric stack 30 housed within the housing 20, the electric stack 30 being composed of a plurality of single cells 100 stacked together along a stacking direction, wherein each single cell 100 includes a membrane electrode assembly 200 and two monopolar plates 300 located on both sides of the membrane electrode assembly 200, wherein the membrane electrode assembly 200 includes a proton exchange membrane, an anode catalyst layer and a cathode catalyst layer located on both sides of the proton exchange membrane, and anode-side and cathode-side gas diffusion layers located on the outermost sides, and wherein one of the monopolar plates 300 is provided with a reactant flow field for a cathode gas to flow, for delivering the cathode gas (e.g., compressed air from a cathode gas source such as an atmosphere, an oxygen storage tank, etc. compressed by a compressor) to the cathode-side gas diffusion layer of the membrane electrode assembly 200, and thus can be referred to as a cathode plate, while the other monopolar plate 300 is provided with a reactant flow field for an anode gas to flow, for delivering the anode gas (e.g., a hydrogen-containing gas such as hydrogen gas or other hydrogen-containing gas such as methane, natural gas, etc. from an anode gas source such as a hydrogen storage tank) to the anode-side gas diffusion layer of the membrane electrode assembly 200, and thus can be referred to as an anode plate. In particular, in the embodiment shown, the fuel cell 10 has a single cell structure in which each single cell 100 is independent of each other. Of course, this is merely exemplary, and in an embodiment not shown, the fuel cell 10 can also have other structures, for example, the electric stack 30 of the fuel cell 10 can be composed of a plurality of bipolar plates and a plurality of membrane electrode assemblies stacked together in an alternating manner, wherein each membrane electrode assembly is located between two bipolar plates, and each bipolar plate is composed of two monopolar plates combined together, so that each bipolar plate is provided with a reactant flow field for an anode gas to flow on one side and faces the anode-side gas diffusion layer of one membrane electrode assembly 200, and is provided with a reactant flow field for a cathode gas to flow on the other side and faces the cathode-side gas diffusion layer of another membrane electrode assembly 200, and is provided with a coolant flow field for a coolant to flow in between (i.e., between the two monopolar plates). Figure 1

[0045] ​During the operation of the fuel cell 10, the anode gas and cathode gas undergo an electrochemical reaction at the membrane electrode assembly 200 to generate electrical energy. Specifically, the anode gas flows through the reactant stream field of the monopolar plate 300, which serves as the anode plate, and is diffused to the anode catalyst layer by the gas diffusion layer on the anode side. The cathode gas flows through the monopolar plate 300, which serves as the cathode plate, and is diffused to the cathode catalyst layer by the gas diffusion layer on the cathode side. At the anode catalyst layer, the anode gas decomposes into protons and electrons. Protons can be transported to the cathode catalyst layer by water molecules in the proton exchange membrane, while electrons, unable to pass through the proton exchange membrane, can only reach the cathode catalyst layer through an external circuit. This provides power to the load on the external circuit electrically connected to the fuel cell 10. The protons and electrons reaching the cathode catalyst layer combine with the cathode gas, generating water and heat simultaneously. As mentioned above, the current is generated through the decomposition of protons and electrons in the anode gas and their combination with the cathode gas; therefore, the current density of the single cell 100 is related to the concentration of the reactants (i.e., the anode and cathode gases). The inventors of this disclosure have discovered that as reactants are consumed, the reactant concentration in the upstream portion of the reactant flow field is higher than that in the downstream portion, resulting in a higher current density in the upstream portion than in the downstream portion. The decrease in current density in the downstream portion of the reactant flow field limits the power level and operating efficiency of the single cell 100.

[0046] To increase the reactant concentration in the downstream portion of the flow field reaction zone, the inventors of this disclosure propose a monopolar plate 300 with an improved flow channel design, which can be used as either an anode plate or a cathode plate. Reference is made below. Figures 2-10 Detailed description of alternative, but non-limiting, implementations of the monopolar plate according to this disclosure.

[0047] refer to Figures 2-4 ,in, Figure 2 A schematic front view of a monopolar plate according to one embodiment of the present disclosure is shown. Figure 3 It shows along Figure 2 A schematic cross-sectional view of the monopole plate taken from line III-III in the diagram, and Figure 4 It shows along Figure 2 A schematic cross-sectional view of a monopolar plate taken along line IV-IV. The monopolar plate 300 has a first side 310 intended to face the membrane electrode assembly and a second side 320 opposite to the first side 310, the second side 320 intended to face another monopolar plate 300, so as to combine with the other monopolar plate 300 to form a bipolar plate. Figure 2As shown in the dashed box, the monopolar plate 300 has a flow field reaction zone 330, two common pipe zones 340 located on both sides of the flow field reaction zone 330, and a sealing zone 350 surrounding the flow field reaction zone 330 and the two common pipe zones 340. The two common pipe zones 340 are located on both sides of the flow field reaction zone 330 along the longitudinal direction L, and each has a reactant inlet 341 for receiving reactants and extending through the monopolar plate 300. The flow field reaction zone 330 is provided with a plurality of flow channels 331, each of which extends along the longitudinal direction L and is spaced apart from adjacent flow channels 331 along a transverse direction T that is transverse to (or perpendicular to) the longitudinal direction L. In other words, these flow channels 331 are arranged along the transverse direction T, with two peripheral flow channels 331P adjacent to the sealing zone 350, while the other flow channels 331 are located between these two peripheral flow channels 331P. Furthermore, each flow channel 331 is in fluid communication with the reactant inlet 341 and the reactant outlet 342, so that reactants from the reactant inlet 341 can be delivered into each flow channel 331 and discharged through the reactant outlet 342 after flowing through each flow channel 331. More specifically, fresh reactants from a common conduit can enter the first side 310 of the monopolar plate 300 through reactant inlet 341 and (e.g., through a distribution area on the reactant inlet 341 side) be conveyed into individual flow channels 331. After flowing through the individual flow channels 331, the reactants can (e.g., through a distribution area on the reactant outlet 342 side) converge at reactant outlet 342 and be discharged from the first side 310 of the monopolar plate 300 through reactant outlet 342. Further, as Figure 2As shown, the multiple channels 331 in the flow field reaction zone 330 are defined by multiple ridges 332. That is, the flow field reaction zone 330 is also provided with multiple ridges 332 for defining multiple channels 331. Each ridge 332 extends along the longitudinal direction L and is spaced apart from adjacent ridges 332 along the transverse direction T. That is, these ridges 332 are arranged along the transverse direction T. After the monopolar plate 300 is assembled with the corresponding membrane electrode assembly 200, each ridge 332 will abut against the gas diffusion layer of the membrane electrode assembly 200. The reactants flowing in each channel 331 can be diffused to the catalyst layer by the gas diffusion layer as described above, thereby undergoing an electrochemical reaction with another reactant to generate electrical energy. In this configuration, two peripheral flow channels 331P of the plurality of flow channels 331 are adjacent to the sealing region 350, while the remaining flow channels 331 are located between these two peripheral flow channels 331P. Each ridge 332 has one flow channel 331 on each side, such that each ridge 332 is located between its two adjacent flow channels 331. Furthermore, the longitudinal direction L defines the flow direction of the reactants in the flow field reaction zone 330; that is, the reactants entering the flow field reaction zone 330 will flow generally along the longitudinal direction L in each flow channel 331 until they are discharged from the flow field reaction zone 330.

[0048] Continue to refer to Figures 2-4 The sealed area 350 is provided with a bypass channel 351, which has an upstream end 352 leading to the reactant inlet 341 and a downstream end 353 leading to the flow field reaction area 330. That is, the two ends of the bypass channel 351 lead to the reactant inlet 341 and the flow field reaction area 330, respectively, while the portion of the bypass channel 351 between its two ends is located within the sealed area 350, thus sealing and isolating it from the flow field reaction area 330 and the common conduit area 340. Specifically, as... Figure 2 As shown, the downstream end 353 of the bypass channel 351 leads to one of the two peripheral flow channels 331P adjacent to the sealing area 350, and each of the plurality of ridges 332 continuously arranged from the peripheral flow channel 331P constitutes a connecting ridge 332C. That is, the plurality of ridges 332 continuously arranged from the peripheral flow channel 331P form a set of connecting ridges 332C. This set of connecting ridges 332C includes the ridge 332 adjacent to the peripheral flow channel 331P and a plurality of ridges 332 continuously arranged from the ridge 332 along the transverse direction T. Each connecting ridge 332C has a notch 333 that fluidly connects the two flow channels 331 on its two sides. The notch 333 is formed by a recess of the connecting ridge 332C that is recessed relative to the rest of the portion. That is, each connecting ridge 332C allows the two flow channels 331 on its two sides to fluidly communicate with each other. In particular, as Figure 2As shown, the downstream end 353 of the bypass channel 351 is positioned at the midpoint of the peripheral flow channel 331P along the longitudinal direction L. Of course, this is merely exemplary; in embodiments not shown, the downstream end 353 of the bypass channel 351 may also be positioned downstream of the midpoint of the peripheral flow channel 331P. Specifically, the downstream end 353 is oriented along the transverse direction T so that it can deliver reactants into the peripheral flow channel 331P along the transverse direction T. In particular, as... Figure 4 As shown, the bottom of the notch 333 of each connecting ridge 332C is higher than the bottom of the flow channel 331. That is, the distance between the bottom of the notch 333 and the bottom of the flow channel 331 measured in the thickness direction H, which is perpendicular to both the transverse direction T and the longitudinal direction L, is not zero, as will be described in detail below. This ensures that the coolant can flow smoothly through the coolant flow field to help the monopole plate 300 dissipate heat.

[0049] In the above configuration, fresh reactants from reactant inlet 341 can be transported not only to each flow channel 331, but also to the middle position of the peripheral flow channel 331P adjacent to the sealing area 350 via bypass channel 351. The notch 333 of each connecting ridge 332C allows fresh reactants to diffuse between the flow channels 331 adjacent to these connecting ridges 332C, thereby increasing the reactant concentration in the downstream portion of these flow channels 331. In other words, fresh reactants can be supplied to the downstream portion of the flow field reaction zone 330 from the middle position on one side of the flow field reaction zone 330, thereby at least partially increasing the reactant concentration in the downstream portion of the flow field reaction zone 330, and thus increasing the current density in the downstream portion of the flow field reaction zone 330, thereby improving the power level and operating efficiency of the single cell 100.

[0050] like Figures 2-4 As shown, the notches 333 of each connecting ridge 332C are aligned (also referred to as aligned) with each other along the lateral direction T and aligned with the downstream end 353 of the bypass channel 351. The alignment or alignment referred to here means that at least one imaginary straight line oriented along the lateral direction T extends through the downstream end 353 of the bypass channel 351 and the notches 333 of each connecting ridge 332C. In this configuration, fresh reactants discharged from the downstream end 353 of the bypass channel 351 can diffuse more easily between the flow channels 331 adjacent to each connecting ridge 332C, thereby more effectively increasing the reactant concentration in the downstream portion of the flow field reaction zone 330 and thus increasing the current density in the downstream portion of the flow field reaction zone 330.

[0051] like Figures 2-4As shown, the seal zone 350 is provided with two bypass channels 351, wherein the upstream ends 352 of the two bypass channels 351 are both open to the reactant inlet 341, and the downstream ends 353 of the two bypass channels 351 are respectively open to two peripheral flow channels 331P adjacent to the seal zone 350, that is, the downstream ends 353 of the two bypass channels 351 are located at two sides of the flow field reaction zone 330 along the transverse direction T, wherein the downstream end 353 of one bypass channel 351 is open to one of the two peripheral flow channels 331P adjacent to the seal zone 350, and the downstream end 353 of the other bypass channel 351 is open to the other peripheral flow channel 331P, and the downstream ends 353 of the two bypass channels 351 are respectively located at the middle positions of the corresponding peripheral flow channels 331P along the longitudinal direction L. In addition, the plurality of ridges 332 arranged continuously from the two peripheral flow channels 331P constitute two groups of communicating ridges 332C, that is, the plurality of ridges 332 arranged continuously from one peripheral flow channel 331P constitute one group of communicating ridges 332C, and the plurality of ridges 332 arranged continuously from the other peripheral flow channel 331P constitute the other group of communicating ridges 332C, wherein each communicating ridge 332C is provided with a notch 333. In this configuration, the two groups of communicating ridges 332C allow fresh reactants from the two bypass channels 351 to diffuse between the flow channels 331 adjacent to these communicating ridges 332C, and since the downstream ends 353 of the two bypass channels 351 are located at two sides of the flow field reaction zone 330, fresh reactants can be supplied from the middle positions of the two sides of the flow field reaction zone 330 to the downstream part of the flow field reaction zone 330, thereby more significantly increasing the reactant concentration in the downstream part of the flow field reaction zone 330, and thus increasing the current density in the downstream part of the flow field reaction zone 330.

[0052] As Figures 2-4As shown, one ridge 332 in the flow field reaction zone 330 constitutes a separation ridge 332S which does not have notches 333, or in other words, the cross section of the separation ridge 332S remains unchanged along the longitudinal direction L, thus the separation ridge 332S can isolate the flow channels 331 on its two sides from each other, thus prohibiting the two flow channels 331 from being in fluid communication with each other. In addition, each ridge 332 on the two sides of the separation ridge 332S constitutes a communication ridge 332C, that is, two groups of communication ridges 332C are formed on the two sides of the separation ridge 332S, and the separation ridge 332S isolates the two groups of communication ridges 332C from each other. In this configuration, the two groups of communication ridges 332C allow fresh reactants from the two bypass channels 351 to diffuse between the flow channels 331 on the two sides of the separation ridge 332S, but due to the presence of the separation ridge 332S, fresh reactants from the two bypass channels 351 cannot mix with each other, thus avoiding the fresh reactants from the two bypass channels 351 interfering with each other's flow, and thus more reliably increasing the reactant concentration in the downstream part of the flow field reaction zone 330, thus more reliably increasing the current density in the downstream part of the flow field reaction zone 330. In particular, the separation ridge 332S is located at the middle position of the flow field reaction zone 330 along the transverse direction T, in other words, the number of ridges 332 on the two sides of the separation ridge 332S differs by at most 1, thus fresh reactants from one bypass channel 351 can be used to supplement the reactant concentration in one half of the downstream part of the flow field reaction zone 330, and fresh reactants from the other bypass channel 351 can be used to supplement the reactant concentration in the other half of the downstream part of the flow field reaction zone 330, thus more evenly increasing the reactant concentration in the downstream part of the flow field reaction zone 330, and thus more evenly increasing the current density in the downstream part of the flow field reaction zone 330. It should be noted that the above embodiment is merely exemplary, in an embodiment not shown, there can be more than one separation ridge 332S between the two groups of communication ridges 332C, thus although fresh reactants cannot be supplemented to the flow channels 331 between the two separation ridges 332S, the fresh reactants from the two bypass channels 351 can be more reliably prevented from mixing with each other by the multiple separation ridges 332S. Of course, the above embodiment is merely exemplary, in an embodiment not shown, there can be no separation ridge 332S, that is, each ridge 332 in the flow field reaction zone 330 constitutes a communication ridge 332C, that is, each ridge 332 in the flow field reaction zone 330 is provided with notches 333. In this configuration, fresh reactants transported by any bypass channel 351 can diffuse between each flow channel 331 in the flow field reaction zone 330, thus the reactant concentration in the downstream part of the entire flow field reaction zone 330 can also be increased, and the processing difficulty of the monopolar plate 300 can be reduced.

[0053] Reference Figures 5-7 wherein, Figure 5a schematic front view of a monopolar plate according to another embodiment of the present disclosure is shown, Figure 6 a schematic cross-sectional view of the monopolar plate taken along the line VI-VI in Figure 5 and, Figure 7 a schematic cross-sectional view of the monopolar plate taken along the line VII-VII in Figure 2 is shown. Figures 5-7 The illustrated embodiment is substantially identical to the one shown in Figures 2-4 The main difference is that the bottom of the notch 333 of each communication ridge 332C is flush with the bottom of the flow channel 331, and the notches 333 of each communication ridge 332C are aligned with each other along the transverse direction T and with the downstream end 353 of the bypass channel 351, thereby forming a distribution channel 335 in the flow field reaction zone 330 extending along the transverse direction T and in fluid communication with the bypass channel 351, which is shown to divide each communication ridge 332C into two sections located on either side thereof so as to intersect with a plurality of flow channels 331. In particular, as shown in Figures 5-7 The flow field reaction zone 330 is provided with two distribution channels 335 separated by a separation ridge 332S, and the sealing zone 350 is provided with two bypass channels 351, the downstream end 353 of each bypass channel 351 opening into one distribution channel 335 so that each distribution channel 335 is in fluid communication with one bypass channel 351. In this configuration, fresh reactant from each bypass channel 351 can be distributed in the distribution channel 335 unimpeded by the ridges 332 to each flow channel 331, thereby enabling more efficient replenishment of fresh reactant to the downstream portion of the flow field reaction zone 330 and, consequently, increasing the reactant concentration and current density in the downstream portion of the flow field reaction zone 330.

[0054] Reference is made to Figure 8 wherein a schematic front view of a monopolar plate according to another embodiment of the present disclosure is shown. Figure 8 The illustrated embodiment is substantially identical to the one shown in Figures 5-7The embodiments shown are generally the same, with the main difference being that each connecting ridge 332C has a guide block 334 in its recess 333. The guide block 334 protrudes from the bottom of the recess 333, thereby dividing the recess 333 into an upstream portion 333U and a downstream portion 333D located on both sides of the guide block 334. The upstream portion 333U is aligned with the downstream end 353 of the bypass channel 351 along the lateral direction T, while the downstream portion 333D is offset downstream relative to the downstream end 353 of the bypass channel 351 along the longitudinal direction L. In this configuration, the upstream portion 333U of the notch 333 of each connecting ridge 332C is aligned with the downstream end 353 of the bypass channel 351 along the lateral direction T. Due to the presence of the guide blocks 334, fresh reactants discharged from the downstream end 353 of the bypass channel 351 can smoothly enter the inner channel 331 along the lateral direction T without being significantly carried away by reactants flowing along the longitudinal direction L in the outer channel 331 (e.g., the peripheral channel 331P). Furthermore, since the downstream portion 333D of the notch 333 of each connecting ridge 332C allows fresh reactants to diffuse between the channels 331, this configuration helps to replenish fresh reactants to the entire downstream portion of the flow field reaction zone 330, thereby reliably increasing the reactant concentration and current density in the entire downstream portion of the flow field reaction zone 330. Specifically, as... Figure 8 As shown, the guide blocks 334 in each connecting ridge 332C are configured such that the lateral dimension (i.e., the dimension measured along the lateral direction T) of the guide block 334 near the downstream end 353 of the bypass channel 351 is greater than the lateral dimension of the guide block 334 far from the downstream end 353 of the bypass channel 351. In other words, the lateral dimension of the guide block 334 closer to the downstream end 353 is larger, and conversely, the lateral dimension of the guide block 334 farther from the downstream end 353 is smaller. In this configuration, since the necessity of guiding fresh reactants decreases as the downstream end 353 moves away from the bypass channel 351, the lateral dimensions of the guide blocks 334 at the downstream end 353 of the bypass channel 351 can be reduced to minimize the obstruction of these guide blocks 334 to the reactants flowing along the longitudinal direction L. This allows the guide blocks 334 to guide fresh reactants while avoiding excessive influence of the guide blocks 334 on the flow of reactants in each channel 331, thereby preventing the guide blocks 334 from affecting the efficiency of the electrochemical reaction.

[0055] refer to Figure 9 The diagram shows a schematic front view of a monopolar plate according to another embodiment of the present disclosure. Figure 9 The embodiments shown are the same as Figure 8 The embodiments shown are largely the same, with the main difference being that, as Figure 8In an alternative to the implementation of the flow field reaction zone 330 shown in FIG. 3, the flow field reaction zone 330 is provided with a flow guide bar 336 in the distribution channel 335, which extends along the transverse direction T from the downstream end 353 of the bypass channel 351 and protrudes from the bottom of the distribution channel 335, thereby dividing the distribution channel 335 into an upstream section 335U and a downstream section 335D on either side of the flow guide bar 336, wherein the upstream section 335U is aligned with the downstream end 353 of the bypass channel 351 along the transverse direction T, while the downstream section 335D is offset downstream relative to the downstream end 353 of the bypass channel 351 along the longitudinal direction L. Of course, the flow guide bar 336 extends only over a partial length of the distribution channel 335, such that the upstream section 335U and the downstream section 335D of the distribution channel 335 can be in fluid communication with each other at the ends of the flow guide bar 336. In this configuration, the reactants from the upstream portions of the flow channels 331 will be mixed thoroughly with the fresh reactants from the bypass channel 351 in the upstream section 335U of the distribution channel 335, while the mixed reactants will enter the downstream section 335D of the distribution channel 335 and be distributed from the downstream section 335D of the distribution channel 335 into the downstream portions of the flow channels 331, thereby allowing for a more uniform increase in the reactant concentration in the downstream portions of the flow field reaction zone 330, and hence a more uniform increase in the current density in the downstream portions of the flow field reaction zone 330.

[0056] Reference is made to Figure 10 wherein a schematic front view of a monopolar plate according to another embodiment of the present disclosure is shown. Figure 10 The illustrated embodiment is substantially the same as the Figure 9 The illustrated embodiment is substantially the same as the Figure 9 In an alternative to the implementation of the flow field reaction zone 330 shown in FIG. 3, the flow field reaction zone 330 is provided with a flow guide bar 336 in the distribution channel 335, which extends along the transverse direction T from the downstream end 353 of the bypass channel 351 and protrudes from the bottom of the distribution channel 335, thereby dividing the distribution channel 335 into an upstream section 335U and a downstream section 335D on either side of the flow guide bar 336, wherein the upstream section 335U is aligned with the downstream end 353 of the bypass channel 351 along the transverse direction T, while the downstream section 335D is offset downstream relative to the downstream end 353 of the bypass channel 351 along the longitudinal direction L. Of course, the flow guide bar 336 extends only over a partial length of the distribution channel 335, such that the upstream section 335U and the downstream section 335D of the distribution channel 335 can be in fluid communication with each other at the ends of the flow guide bar 336. In this configuration, the reactants from the upstream portions of the flow channels 331 will be mixed thoroughly with the fresh reactants from the bypass channel 351 in the upstream section 335U of the distribution channel 335, while the mixed reactants will enter the downstream section 335D of the distribution channel 335 and be distributed from the downstream section 335D of the distribution channel 335 into the downstream portions of the flow channels 331, thereby allowing for a more uniform increase in the reactant concentration in the downstream portions of the flow field reaction zone 330, and hence a more uniform increase in the current density in the downstream portions of the flow field reaction zone 330. Figure 10As shown, each spoiler block 337 may have an elliptical cross-section, and the major axis of the ellipse is oriented obliquely relative to the lateral direction T and the longitudinal direction L. Of course, in embodiments not shown, all or part of the spoiler blocks 337 may also have cross-sections of other shapes (e.g., circular, triangular, rectangular, etc.).

[0057] Furthermore, the inventors of this disclosure have proposed an improved bipolar plate. (Reference) Figures 11-13 ,in, Figure 11 A schematic front view of a bipolar plate according to one embodiment of the present disclosure is shown. Figure 12 It shows along Figure 11 A schematic cross-sectional view of the bipolar plate taken from line XII-XII in the diagram, and Figure 13 It shows along Figure 11 A schematic cross-sectional view of the bipolar plate taken from line XIII-XIII. (See diagram below.) Figures 11-13 As shown, the bipolar plate 400 includes Figures 2-4 The diagram shows a monopolar plate 300 and another monopolar plate 500 combined with it. One of the monopolar plates 300 and 500 can be used as an anode plate, and the other as a cathode plate. A first side 310 of the monopolar plate 300 faces the membrane electrode assembly 200 (shown in dashed lines), while a second side 320 faces the monopolar plate 500. Similarly, the monopolar plate 500 faces the monopolar plate 300 on one side and the other membrane electrode assembly 200 on the other side. Figure 12 As shown, the monopolar plate 300 has multiple coolant channels 321 for coolant flow on its second side 320. These coolant channels 321 are passively formed on the back side of the ridge 332 by stamping channels 331 on the first side 310 of the monopolar plate 300, so each coolant channel 321 corresponds to each ridge 332. Similarly, the monopolar plate 500 has multiple coolant channels 521 for coolant flow on the side facing the monopolar plate 300. These coolant channels 521 are passively formed on the back side of the ridge 532 by stamping channels 531 on the other side of the monopolar plate 500, so each coolant channel 521 corresponds to each ridge 532, and each coolant channel 521 together with each coolant channel 321 forms the coolant flow field. Figure 13 As shown, due to the formation of the coolant flow channel 321, its cross-section (also known as the coolant flow area) will decrease at the notch 333 of the corresponding connecting ridge 332C. However, since the bottom of the notch 333 of each connecting ridge 332C is higher than the bottom of the flow channel 331, the cross-section of the coolant flow channel 321 is not reduced to zero due to the notch 333, thus allowing the coolant to still flow through each coolant flow channel 321. Furthermore, as... Figure 12 and Figure 13As shown, each coolant channel 521 is aligned with each coolant channel 321. Therefore, even if the cross-section of each coolant channel 321 is locally reduced, each coolant channel 521 can still ensure that the coolant can flow through the coolant flow field at a sufficient flow rate, thereby ensuring efficient heat dissipation of the monopole plate 300 and monopole plate 500.

[0058] refer to Figures 14-16 ,in, Figure 14 A schematic front view of a bipolar plate according to another embodiment of the present disclosure is shown. Figure 15 It shows along Figure 14 A schematic cross-sectional view of the bipolar plate taken by line XV-XV in the diagram, and Figure 16 It shows along Figure 14 A schematic cross-sectional view of the bipolar plate taken along line XVI-XVI. (Compared to...) Figures 11-13 The difference shown is that, Figures 14-16 The bipolar plate 400 shown includes Figures 5-7 The monopolar plate 300 and another monopolar plate 500 combined with the monopolar plate 300 are shown. Figure 16 As shown, since the bottom of the notch 333 of each connecting ridge 332C is flush with the bottom of the flow channel 331, the cross-section of the coolant flow channel 321 will be reduced to zero at the notch 333 of the corresponding connecting ridge 332C. However, due to the presence of each coolant flow channel 521, the coolant can still flow through the coolant flow field, thereby ensuring reliable heat dissipation of the monopole plate 300 and monopole plate 500.

[0059] It should be pointed out that, although in Figures 11-16 In the illustrated embodiment, one of the two monopolar plates constituting the bipolar plate 400 is composed of a monopolar plate 300 according to the present disclosure. However, this is merely exemplary. In embodiments not shown, both monopolar plates constituting the bipolar plate 400 can be composed of a monopolar plate 300 according to the present disclosure. Of course, to ensure smooth flow of coolant through the coolant flow field, the two monopolar plates 300 intended to be combined can be configured such that the notches 333 of the respective connecting ridges 332C of one monopolar plate 300 and the notches 333 of the respective connecting ridges 332C of the other monopolar plate 300 are offset from each other along the longitudinal direction L, to avoid the cross-section of the coolant flow channels 321 of the two monopolar plates 300 decreasing at the same location. Furthermore, in other embodiments not shown, one or both of the two monopolar plates constituting the monopolar plate 400 can also be composed of a monopolar plate 300 and a monopolar plate 300. Figures 2-7 The monopolar plate 300 is configured in different implementation methods.

[0060] The above described, by means of the drawings, alternative but not limiting embodiments of the monopolar plate, the bipolar plate and the fuel cell according to the present disclosure in detail. Modifications and additions to the techniques and structures and re-combinations of features in the embodiments apparent to those of ordinary skill in the art without departing from the spirit and essence of the present disclosure should be considered as included within the scope of the present disclosure. Therefore, these modifications and additions and re-combinations of features in the embodiments that can be conceived under the teachings of the present disclosure should be considered as part of the present disclosure. The scope of the present disclosure includes equivalent technologies known at the filing date of the present disclosure and equivalent technologies not yet foreseen.

Claims

1. A monopolar plate, characterized in that The monopolar plate (300) is provided on one side with a flow field reaction zone (330), a common duct zone (340), and a sealing zone (350) surrounding the flow field reaction zone (330) and the common duct zone (340), wherein the common duct zone (340) is provided with a reactant inlet (341), wherein the flow field reaction zone (330) is provided with a plurality of flow channels (331) in communication with the reactant inlet (341), each flow channel (331) extending along a longitudinal direction (L) and being spaced apart from an adjacent flow channel (331) along a transverse direction (T), the plurality of flow channels (331) including a peripheral flow channel (331P) adjacent to the sealing zone (350) and being defined by a plurality of ridges (332) such that each ridge (332) is located between two flow channels (331), and wherein the sealing zone (350) is provided with a bypass channel (351) having an upstream end (352) opening to the reactant inlet (341) and a downstream end (353) opening to the peripheral flow channel (331P), and each of the plurality of ridges (332) arranged successively from the peripheral flow channel (331P) constitutes a communication ridge (332C), each communication ridge (332C) being provided with a notch (333) allowing two flow channels (331) on two sides thereof to communicate with each other.

2. The monopolar plate according to claim 1, characterized in that The sealing zone (350) is provided with one bypass channel (351), and each ridge (332) constitutes a communication ridge (332C).

3. The monopolar plate of claim 1, wherein, The sealing zone (350) is provided with two bypass channels (351), the plurality of flow channels (331) including two peripheral flow channels (331P) adjacent to the sealing zone (350), the upstream ends (352) of the two bypass channels (351) both opening to the reactant inlet (341), and the downstream ends (353) of the two bypass channels (351) opening to the two peripheral flow channels (331P) respectively.

4. The monopolar plate according to claim 3, characterized in that The plurality of ridges (332) arranged successively from the two peripheral flow channels (331P) constitutes two groups of communication ridges (332C), and there is a separation ridge (332S) between the two groups of communication ridges (332C), the separation ridge (332S) isolating two flow channels (331) on two sides thereof from each other.

5. The monopolar plate according to claim 4, characterized in that The separation ridge (332S) is located at a middle position of the flow field reaction zone (330) along the transverse direction (T).

6. The monopolar plate according to any one of claims 1-5, characterized in that, The downstream end (353) of the bypass channel (351) is positioned at a middle position of the peripheral flow channel (331P) along the longitudinal direction (L).

7. The monopolar plate according to any one of claims 1-5, characterized in that, The portion of the bypass channel (351) between the upstream end (352) and the downstream end (353) is sealingly isolated from the flow field reaction zone (330) and the common duct zone (340).

8. The monopolar plate according to any one of claims 1-5, characterized by The notch (333) of each communication ridge (332C) is aligned with the downstream end (353) of the bypass channel (351) along the transverse direction (T).

9. The monopolar plate according to any one of claims 1-5, characterized by A flow guide block (334) is provided in the notch (333) of each communication ridge (332C), which separates the notch (333) into an upstream portion (333U) and a downstream portion (333D) located on both sides of the notch (333), and the upstream portion (333U) is aligned with the downstream end (353) of the bypass channel (351) along the transverse direction (T).

10. The monopolar plate according to claim 9, characterized in that The transverse dimension of the flow guide block (334) close to the peripheral flow channel (331P) is greater than the transverse dimension of the flow guide block (334) away from the peripheral flow channel (331P).

11. The monopolar plate according to any one of claims 1-5, characterized by The bottom of the notch (333) of each communication ridge (332C) is higher than the bottom of the flow channel (331).

12. The monopolar plate according to any one of claims 1-5, characterized by The bottom of the notch (333) of each communication ridge (332C) is flush with the bottom of the flow channel (331), and the notch (333) of each communication ridge (332C) is aligned with the downstream end (353) of the bypass channel (351) along the transverse direction (T) to form a distribution channel (335) extending along the transverse direction (T) in the flow field reaction zone (330).

13. The monopolar plate of claim 12, wherein, A flow guide strip (336) is provided in the distribution channel (335), which extends from the downstream end (353) of the bypass channel (351) along the transverse direction (T) and separates the distribution channel (335) into an upstream section (335U) and a downstream section (335D) located on both sides of the distribution channel (335) and in communication with each other, and the upstream section (335U) is aligned with the downstream end (353) of the bypass channel (351) along the transverse direction (T).

14. The monopolar plate of claim 12, wherein, A plurality of turbulence blocks (337) separated from each other are provided in the distribution channel (335).

15. A bipolar plate, characterized by Comprising: an anode plate; and a cathode plate combined with the anode plate, wherein at least one of the anode plate and the cathode plate is composed of a monopolar plate according to any one of claims 1-14.

16. A fuel cell, characterized by Comprising: a housing (20); and a stack (30) accommodated in the housing (20), wherein the stack (30) comprises a plurality of membrane electrode assemblies (200) and a plurality of bipolar plates stacked together in an alternating manner, wherein each membrane electrode assembly (200) is located between two bipolar plates, and wherein at least one bipolar plate is composed of a bipolar plate according to claim 15.

17. A fuel cell, characterized by Comprising: a housing (20); and a stack (30) accommodated in the housing (20), wherein the stack (30) comprises a plurality of single cells (100) combined together, each single cell (100) comprising a membrane electrode assembly (200) and an anode plate and a cathode plate located on both sides of the membrane electrode assembly (200), and wherein at least one of the anode plate and the cathode plate is composed of a monopolar plate according to any one of claims 1-14.

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