CN114023988B - Fuel cell plate and cell - Google Patents

Abstract

The application discloses a fuel cell polar plate, which comprises a substrate, wherein the substrate is provided with a first surface and a second surface, the first surface is stamped, a flow channel which is sunken towards the second surface is formed on the first surface, a convex ridge which is far away from the first surface is formed on the second surface, a flow channel is formed between any two adjacent convex ridges on the second surface, and the flow channel forms a flow field area, so that the flow field areas are formed on the first surface and the second surface. The fuel cell polar plate provided by the application can be used as a cathode plate and an anode plate and can also be used as a bipolar plate, and has a simple structure and reliable use. The application also discloses a battery unit which comprises two fuel cell polar plates, a cathode side gas diffusion layer and an anode side gas diffusion layer; the cathode-side gas diffusion layer and the anode-side gas diffusion layer are provided between the two fuel cell plates. By assembling a plurality of battery cells, the fuel cell stack can be quickly constructed.

Description

Fuel cell plate and cell

Technical Field

The application relates to the technical field of fuel cells, in particular to a fuel cell polar plate and a cell unit.

Background

The polar plate is used as a core component in the fuel cell, has functions of collecting current and supporting a membrane electrode, and can also distribute reaction gas.

The existing polar plate is complex in design and high in processing difficulty. Particularly, the bipolar plate has the advantages that due to different structures of the cathode plate and the anode plate, a plurality of dies are required to be opened, so that development and manufacturing period is increased, and meanwhile, development and development cost is increased.

Disclosure of Invention

The application aims to overcome the defects in the prior art and provide a fuel cell polar plate and a cell unit.

In order to achieve the technical purpose, the application provides a fuel cell polar plate, which comprises a substrate, wherein the substrate is provided with a first surface and a second surface, and the first surface and the second surface are mutually positive and negative; stamping the first surface, forming a flow channel recessed toward the second surface on the first surface, and forming a raised ridge raised away from the first surface on the second surface; a circulation channel is formed between any two adjacent convex ridges on the second surface; the flow channel forms a flow field region for guiding the flow of the reaction gas; the first face and the second face are provided with flow field areas;

The substrate is provided with: a first inlet arranged on a first side of the flow field region along a first direction; a first outlet disposed on a second side of the flow field region in a first direction; when the fuel cell plate is used as a plate of the first reaction gas, the first reaction gas can enter the flow field region through the first inlet, is guided by the flow field region, and can be discharged through the first outlet; the first inlet is arranged on the third side of the flow field region; the second inlets are arranged on the second side of the flow field region along the first direction, and the number of the second inlets is smaller than that of the first inlets; a second outlet arranged on a first side of the flow field region along the first direction; when the fuel cell electrode plate is used as an electrode plate of the second reaction gas, the second reaction gas can enter the second inlet through the first inlet and then enter the flow field region through the second inlet, and the second reaction gas can be discharged through the second outlet after being guided by the flow field region;

the first outlet and/or the second outlet are/is communicated with the first second inlet through a pipeline; the water discharged through the first outlet or the second outlet acts on the second reaction gas in the first inlet through the pipe.

Further, any one of the flow channels extends along the first direction, and a plurality of the flow channels are arranged at intervals along the second direction; the first direction is perpendicular to the second direction.

Further, the flow field area further comprises a first limiting ridge and a second limiting ridge which are arranged at intervals along the second direction, and the plurality of protruding ridges are arranged between the first limiting ridge and the second limiting ridge; the width of the first limit ridge and the second limit ridge along the second direction is larger than that of the protruding ridge along the second direction.

Further, at least a portion of the first outlet is below the flow field region; and/or at least part of the second outlet is below the flow field region.

Further, at least two first second inlets are arranged on the substrate, and the at least two first second inlets are arranged side by side along the extending direction of the side edge of the corresponding flow field area; and/or, at least two second inlets II are arranged on the substrate and are arranged side by side along the extending direction of the side edge of the corresponding flow field area; and/or, at least two second outlets are arranged on the substrate, and the at least two second outlets are arranged side by side along the extending direction of the side edge of the corresponding flow field area.

Further, a third inlet and a third outlet are also arranged on the substrate; one of the third inlet and the third outlet is arranged on the first side of the flow field region, and the other of the third inlet and the third outlet is arranged on the second side of the flow field region; the coolant can enter the flow field region through the third inlet and can exit through the third outlet.

Further, the base plate is also provided with a positioning hole.

Further, a voltage inspection area is also arranged on the substrate.

The application also provides a battery unit which comprises the two fuel cell polar plates, a cathode side gas diffusion layer and an anode side gas diffusion layer; the cathode-side gas diffusion layer and the anode-side gas diffusion layer are disposed between the two fuel cell plates.

Further, the flow field regions of the two fuel cell plates are staggered in position along the second direction.

The fuel cell polar plate comprises a base plate, wherein the base plate is provided with a first surface and a second surface, the first surface is stamped, a flow channel which is sunken towards the second surface is formed on the first surface, a convex ridge which is far away from the first surface is formed on the second surface, a flow channel is formed between any two adjacent convex ridges on the second surface, and the flow channel forms a flow field area, so that the flow field areas are formed on the first surface and the second surface. The fuel cell polar plate provided by the application can be used as a cathode plate and an anode plate and can also be used as a bipolar plate, and has a simple structure and reliable use.

The application also provides a battery unit which comprises the two fuel cell polar plates, a cathode side gas diffusion layer and an anode side gas diffusion layer; the cathode-side gas diffusion layer and the anode-side gas diffusion layer are provided between the two fuel cell plates. By assembling a plurality of battery cells, the fuel cell stack can be quickly constructed.

Drawings

Fig. 1 is a schematic structural diagram of a polar plate according to the present application;

FIG. 2 is a schematic perspective view of the pole plate shown in FIG. 1;

FIG. 3 is an enlarged schematic view of the in-loop structure of FIG. 2;

FIG. 4 is a cross-sectional view taken along the direction A-A in FIG. 1;

fig. 5 is a schematic structural diagram of a battery unit according to the present application;

Fig. 6 is a schematic structural diagram of another battery unit according to the present application.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

The application provides a fuel cell polar plate 100, which comprises a substrate 110, wherein the substrate 110 is provided with a first surface 111 and a second surface 112, and the first surface 111 and the second surface 112 are mutually front and back surfaces; stamping the first face 111, forming a flow channel on the first face 111 recessed toward the second face 112, and forming a raised ridge 121 on the second face 112 raised away from the first face 111; a flow channel is formed between any two adjacent raised ridges 121 on the second face 112; the flow channels constitute flow field regions 120 for guiding the flow of the reaction gases; the first side 111 and the second side 112 each have a flow field region 120 thereon.

First, it should be explained that, for the fuel cell, the reaction gas includes a fuel gas and an oxidizer gas. Wherein fuel gas enters from the anode end of the fuel cell and oxidant gas enters from the cathode end of the fuel cell; subsequently, the fuel gas emits electrons at the anode end, and the electrons are conducted to the cathode through an external circuit to combine with the oxidant gas to generate ions; under the action of an electric field, ions migrate to the anode end through the electrolyte and react with fuel gas to form a loop, and current is generated.

One of the first and second reactant gases is a fuel gas, such as hydrogen; the other is an oxidant gas, such as oxygen. It will be readily appreciated that, as oxygen is the primary component of air, air may also be used as the oxidant gas for cost savings.

In one embodiment, the first reactant gas is a fuel gas; the fuel gas enters the flow field region 120 through the first inlet 131, part of the fuel gas reacts with the oxidant gas to generate water, and the other part of the fuel gas does not participate in the reaction and is discharged through the first outlet 132. Correspondingly, the second reaction gas is oxidant gas, the oxidant gas enters the fuel cell through the first inlet 141, the oxidant gas enters the flow field region 120 through the second inlet 142 after reversing, part of the oxidant gas reacts with the fuel gas to generate water, and the other part of the oxidant gas does not participate in the reaction and is discharged through the second outlet 143.

Secondly, it should be explained that when the electrode plate provided by the application is used for constructing a fuel cell, the electrode plate is connected with the membrane electrode, the flow field area 120 of the electrode plate is attached to the membrane electrode, and the reaction gas enters the circulation channel and contacts the membrane electrode.

Specifically, when the electrode plates and the membrane electrode form a fuel cell, one membrane electrode is disposed between the two electrode plates, and both sides of the membrane electrode are respectively in contact with the flow field region 120 of one electrode plate. The flow field region 120 of one of the plates is flowed through by an oxidant gas, wherein the flow field region 120 of the other plate is flowed through by a fuel gas, and the reactant gas is catalyzed by the membrane electrode to undergo an oxidation reaction, generating an electric current and generating water.

The fuel cell electrode plate provided by the application can be used as a single-pole plate for fuel gas and can also be used as a single-pole plate for oxidant gas. When used as a unipolar plate, either the first face 111 or the second face 112 of the plate is connected to the membrane electrode; the fuel cell operates and the reactant gases pass over either the first face 111 or the second face 112 of the plate, contact the membrane electrode, and react chemically.

The fuel cell plate provided by the application can also be used as a bipolar plate. When used as a bipolar plate, the first face 111 of the plate is connected to one membrane electrode and the second face 112 of the plate is connected to the other membrane electrode; the fuel cell operates with the first reactant gas passing over the first face 111 and contacting the corresponding electrode for chemical reaction, and the second reactant gas passing over the second face 112 and contacting the corresponding electrode for chemical reaction.

When the flow field region 120 is constructed on the substrate 110 by stamping, the stamping die acts on the first surface 111 of the substrate 110, so that a part of the plate surface on the first surface 111 is recessed toward the second surface 112, and the recess becomes a flow channel of the flow field region 120 on the first surface 111. It is easy to understand that when the substrate 110 is pressed by the die, the first surface 111 and the second surface 112 deform simultaneously, and the recess on the first surface 111, that is, the protrusion on the second surface 112 becomes the protrusion ridge 121 of the flow field area 120 on the second surface 112, and the flow channel of the flow field area 120 on the second surface 112 is formed between two adjacent protrusions.

Referring to fig. 4, in the embodiment shown in the drawings, the first surface 111 is the left surface of the substrate 110, the second surface 112 is the right surface of the substrate 110, after being punched, the first surface 111 is formed with a recess, the second surface is correspondingly formed with a protrusion, and the non-punched surfaces are in the same plane, that is, the substrate 110 is single-sided protruding. At this time, when the first face 111 is used as a plate face, the undeformed surface serves as the convex ridge 121 of the flow field region 120 on the first face 111 for abutting against the membrane electrode, and the concave recess is for flowing the reaction gas. When the second surface 112 is used as a plate surface, the protrusions are used for abutting against the membrane electrode, and the undeformed surface between two adjacent protrusions is used for flowing the reaction gas.

Thus, due to the stamping nature, the depressions on either first face 111 correspond to the protrusions on one second face 112.

The structure of the plate can be simplified and the versatility of the plate can be improved by stamping the substrate 110 with a single-sided bump.

Further, any one of the flow channels extends along the first direction, and a plurality of the flow channels are arranged at intervals along the second direction; the first direction is perpendicular to the second direction.

It will be readily appreciated that for the first face 111, a recess is formed between adjacent two of the undeformed surfaces, the recess serving as a flow passage for the reactant gas. At this time, the first surface 111 is fitted with a convex ridge 121 of the first surface 111 which is an "undeformed surface" of the recess constituting the flow passage.

When the flow channel extends along the first direction, any one of the raised ridges 121 extends along the first direction; similarly, the plurality of raised ridges 121 on the first face 111 or the second face 112 are spaced apart along the second direction.

Wherein the first direction may be considered as the length direction of the flow field region 120 and the second direction may be considered as the width direction of the flow field region 120.

By arranging the flow channel to extend along a straight line, on one hand, the structure of the flow field region 120 can be simplified, and the polar plate can be formed conveniently; on the other hand, under the condition that the contact area of the reaction gas and the membrane electrode is not affected, the flow channel extending in a straight line is more beneficial to the flow of the reaction gas.

Further, the substrate 110 is provided with: a flow field region 120 for guiding the flow of the reaction gas; a first inlet 131 provided at a first side of the flow field region 120 in a first direction; a first outlet 132 disposed on a second side of the flow field region 120 in a first direction; when the fuel cell plate 100 is used as a plate for the first reactant gas, the first reactant gas can enter the flow field region 120 through the first inlet 131, and the first reactant gas can be discharged through the first outlet 132 through the guidance of the flow field region 120.

The substrate 110 is further provided with: a second inlet one 141 provided at a third side of the flow field region 120; a second inlet 142 provided on a second side of the flow field region 120 along the first direction; a second outlet 143 provided at a first side of the flow field region 120 in the first direction; when the fuel cell plate 100 is used as a plate for the second reactant gas, the second reactant gas can enter the second inlet 142 through the first inlet 141, enter the flow field region 120 through the second inlet 142, and be discharged through the second outlet 143 through the guidance of the flow field region 120.

By providing two inlets (the first inlet 141 and the second inlet 142) for supplying the second reactant gas to the fuel cell, on the one hand, the flow rate and the flow velocity of the second reactant gas into the fuel cell can be regulated so that the second reactant gas sufficiently reacts. On the other hand, the second reaction gas needs to pass through the first inlet 141 and then enter the second inlet 142 and the flow field region 120, so that the flow time and the flow distance of the second reaction gas are long, and at this time, an auxiliary device may be disposed at the first inlet 141 to adjust the state of the second reaction gas; for example, a humidifier is provided for humidifying the second reactant gas; for another example, a cooler is provided for cooling … … the second reactant gas to optimize the reaction of the fuel cell by changing the physical state of the second reactant gas.

It should be noted that, when air is used as the oxidizing gas, the amount of the oxidizing gas supplied to the fuel cell is larger than the amount of the fuel gas supplied. Therefore, the oxidant gas can be made to enter the flow field region 120 from the second inlet one 141, the second inlet two 142 as the second reactive gas, the intake air amount of the air is increased through more inlets, and the flow rate of the air is ensured to be stable.

It should be further added that the third side may be a position different from the first side and the second side, for example, in the embodiment shown in fig. 1, the first direction is a left-right direction, the first side refers to the left side of the flow field region 120, the second side refers to the right side of the flow field region 120, and the third side may be an upper side of the flow field region 120 or a lower side of the flow field region 120. In this way, the structure of the substrate 110 can be utilized efficiently, and the interaction between the second inlet 141 on the third side and the second inlet 142, the first outlet 132 and the second outlet 143 is facilitated (the purpose and method of interaction are described below).

Or the third side may be the first side or the second side. Continuing with the description of the orientation shown in fig. 1, i.e., the first direction is a left-to-right direction, the first side refers to the left side of flow field region 120, and the second side refers to the right side of flow field region 120. At this time, the third side may be the left side of the flow field region 120 or the right side of the flow field region 120. The second inlet 141 may be provided alongside the other inlet or may be provided on the left or right side of the other inlet.

Optionally, referring to fig. 1, at least two second inlets 141 are disposed on the substrate 110, and the at least two second inlets 141 are disposed side by side along the extending direction of the side edge of the corresponding flow field region 120. By increasing the number of the second inlets 141, on the one hand, the flow rate of the second reaction gas can be increased to meet the gas supply requirement of the fuel cell reaction; on the other hand, the second reaction gas can be guided to flow through various positions of the substrate 110, thereby fully utilizing the substrate 110. Meanwhile, when the auxiliary device is arranged at the first second inlet 141, the auxiliary device can work on each first second inlet 141, so that the treatment effect on the second reaction gas is ensured.

Optionally, referring to fig. 1, at least two second inlets 142 are disposed on the substrate 110, where the at least two second inlets 142 are disposed side by side along the extending direction of the side edge of the corresponding flow field region 120; and/or, the substrate 110 is provided with at least two second outlets 143, and the at least two second outlets 143 are arranged side by side along the extending direction of the side edge of the corresponding flow field area 120. By increasing the number of second inlets 142, the flow rate of the second reactant gas into the flow field region 120 can be increased. By increasing the number of the second outlets 143, a larger flow rate of unreacted second reaction gas can be conveniently discharged.

Similarly, optionally, at least two first inlets 131 are disposed on the substrate 110, and the at least two first inlets 131 are disposed side by side along the extending direction of the side edge of the corresponding flow field region 120; and/or, the substrate 110 is provided with at least two first outlets 132, and the at least two first outlets 132 are arranged side by side along the extending direction of the side edge of the corresponding flow field region 120.

By having the first inlet 131 and the first outlet 132, and the second inlet 142 and the second outlet 143 disposed opposite to each other in the first direction on both sides of the flow field region 120, after the reactant gas (the first reactant gas or the second reactant gas) enters the flow field region 120 from one side, the unreacted portion of the gas can flow out directly from the other side along the flow field region 120, thereby ensuring a stable and efficient flow of the reactant gas.

Further, the first inlet 131 is higher than the first outlet 132 in a second direction, which is perpendicular to the first direction. Because the first inlet 131 and the first outlet 132 have a height difference, when the gas with smaller mass enters from the first inlet 131 with higher position and flows from the first outlet 132 with lower position, the gas does not float above the flow field region 120, but can better flow through the whole flow field region 120, thereby enlarging the contact area between the reaction gas and the membrane electrode and promoting the fuel cell reaction.

Similarly, the second inlet 142 is higher than the second outlet 143 in the second direction, which is advantageous for guiding the reaction gas flowing through the entire flow field region 120.

Alternatively, the first inlet 131 and the second outlet 143 are spaced apart along the second direction; and/or the first outlet 132 and the second inlet 142 are spaced apart along the second direction. By providing the inlet of the first reactive gas and the outlet of the second reactive gas, and the outlet of the first reactive gas and the inlet of the second reactive gas on the same straight line, on the one hand, the utilization rate of the structure of the substrate 110 can be improved, and on the other hand, the structure of the electrode plate can be simplified, and the versatility of the electrode plate can be improved.

In order to increase the utilization rate of the reaction gas, it is necessary to ensure that the reaction gas is sufficiently contacted with the membrane electrode. In order to increase the contact area between the reactant gas and the membrane electrode and to avoid the reactant gas from stagnating in the flow field region 120, in one embodiment, the flow field region 120 includes a plurality of raised ridges 121 spaced apart along the second direction, and any raised ridge 121 extends along the first direction.

A flow channel is formed between any two adjacent raised ridges 121, and the flow channel also extends in the first direction. When the electrode plate is connected with the membrane electrode, the raised ridge 121 abuts against the membrane electrode, and the reaction gas passes through the flow channel and contacts with the membrane electrode.

Referring specifically to fig. 1, the first direction is a flowing direction of the reaction gas. The reactant gas enters the flow field region 120 from the corresponding inlet (either the first inlet 131 or the second inlet 142) and flows along the flow channels from left to right or from right to left to the outlet (either the first outlet 132 or the second outlet 143). In the flowing process, part of the reaction gas is catalyzed by the membrane electrode to participate in chemical reaction, and the other part of the reaction gas is discharged through the outlet.

To increase the contact area of the reaction gas with the membrane electrode, the width of the ridge 121 in the second direction may be reduced without affecting the cell performance. It will be readily appreciated that the width of the flow channels in the second direction affects the flow and velocity of the reactant gas, and therefore, by reducing the width of the raised ridges 121, more flow channels can be constructed within the area-limited flow field region 120 without changing the flow channel width, so that the reactant gas better contacts the membrane electrode.

Further, the flow field region 120 further includes a first limiting ridge 122 and a second limiting ridge 123 disposed at intervals along the up-down direction, and the plurality of protruding ridges 121 are disposed between the first limiting ridge 122 and the second limiting ridge 123.

By providing the first and second spacing ridges 122, 123, the extent of the flow field region 120 can be limited to facilitate the connection of the plates to the membrane electrode or assembly or mating with other structures in the fuel cell.

Alternatively, the width of the stopper ridge (the first stopper ridge 122 or the second stopper ridge 123) in the second direction is larger than the width of the protruding ridge 121 in the second direction. It will be appreciated that the raised ridge 121 serves to create a plurality of flow channels, and therefore, the smaller the width of the raised ridge 121, the greater the number of flow channels. Different from the raised ridge 121, the limiting ridge is used as the boundary of the flow field region 120, and when the limiting ridge has a larger width, on one hand, the configuration of the flow field region 120 can be stabilized, and the raised ridge 121 is prevented from being easily deformed due to smaller width stress; on the other hand, when the limiting ridge contacts the membrane electrode or other structures, the contact area of the limiting ridge and the membrane electrode is large, so that the stability of connection of the limiting ridge and the membrane electrode is improved.

Optionally, the limiting ridge is spaced from an adjacent one of the protruding ridges 121, and a flow channel is formed between the limiting ridge and the protruding ridge 121. Or the spacing ridge abuts an adjacent one of the raised ridges 121, with no flow passage therebetween.

It is known that water is generated during the reaction of the fuel cell; it is easy to understand that if a large amount of water is accumulated in the battery structure, the normal circulation of the reaction gas is not facilitated, and the stability of the battery is also affected.

Specifically, the water generated by the reaction flows along with the unreacted reactant gas to the outlet, if the outlet is higher than the flow field region 120 or is close to the flow field region 120, the reactant gas discharged from the flow field region 120 can normally pass through the outlet because of smaller mass, but the discharged water can not easily flow out from the outlet with higher mass because of larger mass, and is easily accumulated between the flow field region 120 and the outlet.

To facilitate drainage of water, in one embodiment, at least a portion of the first outlet 132 is located in the second direction, below the flow field region 120; and/or at least a portion of the second outlets 143 are below the flow field region 120 in a second direction; so that water generated by the fuel cell reaction is discharged through the first outlet 132 or the second outlet 143.

Specifically, when water flows toward the outlet (the first outlet 132 or the second outlet 143), it naturally flows downward due to the influence of its own weight, and then exits through the first outlet 132 or the second outlet 143 lower than the flow field region 120.

Most fuel cell stacks in the market use external humidifiers to increase the humidity inside the stack, thereby ensuring that the stack continues to operate stably and reliably. However, the external humidifier is additionally arranged to act on the electric pile, so that the operation power consumption of the electric pile can be increased, and the actual operation performance of the electric pile can be influenced along with the extension of the operation time of the electric pile.

It is known that water is generated during the reaction of the fuel cell, and water can be used to humidify the reaction gas, thereby realizing humidification of the inside of the stack.

Thus, in one embodiment, the first outlet 132 and/or the second outlet 143 is in communication with the second inlet 141 via a conduit; the water discharged through the first outlet 132 or the second outlet 143 acts on the second reaction gas in the second inlet 141 through a pipe.

It is easily conceivable that the moisture is discharged from the first outlet 132 or the second outlet 143 following the reaction gas, and thus, when the discharged moisture directly flows to the second inlet 141 through the pipe, a part of the reaction gas flows to the second inlet 141 together with the moisture. At this time, if the water mixed with the first reactant gas discharged through the first outlet 132 enters the first second inlet 141, the first reactant gas is easy to enter the first second inlet 141 through the pipeline, thereby interfering with the normal flow of the second reactant gas and also easily affecting the normal operation of the fuel cell.

Thus, in one embodiment, only the second outlet 143 is in communication with the second inlet 141 via a conduit. In this way, the second reaction gas which does not participate in the reaction is discharged from the second outlet 143 with the moisture, and then enters the first inlet 141 again through the pipe. At this time, by providing the pipe, the flow rate of the second reaction gas at the second inlet 141 can be increased and the second reaction gas can be humidified.

In another embodiment, a steam-water separator may be disposed at the first outlet 132 and/or the second outlet 143, after the reactant gas leaves the fuel cell, the gas and the moisture in the reactant gas are separated by the steam-water separator, the gas can be re-input into the fuel cell through the reflux device, so as to improve the utilization rate, and the moisture can be introduced into the first inlet 141 through the pipe line to humidify the second reactant gas input into the fuel cell.

During the reaction of the fuel cell, a large amount of heat is generated. If the fuel cell works in a high-temperature environment for a long time, the reaction speed is influenced, and the service life is also influenced. To cool the fuel cell, in one embodiment, the substrate 110 is provided with a third inlet 151 and a third outlet 152; one of the third inlet 151 and the third outlet 152 is provided at a first side of the flow field region 120, and the other of the third inlet 151 and the third outlet 152 is provided at a second side of the flow field region 120; coolant can enter the flow field region 120 through the third inlet 151 and can be discharged through the third outlet 152.

It should be noted that the coolant may be a cooling liquid or a cooling gas. For example, deionized water or glycol solution may be used as the coolant. It is understood that if the coolant and the reactant gas are simultaneously circulated on the same surface of the substrate 110, the coolant affects the flow rate and flow rate of the reactant gas and also interferes with the normal reaction of the fuel cell. Therefore, when the fuel cell is in operation, the reactant gas passes through the first surface 111 or the second surface 112 of the substrate 110 and contacts the membrane electrode; the coolant passes through the second surface 112 or the first surface 11 of the electrode plate, so that the coolant and the reaction gas flow through the two different surfaces, and the coolant can not influence the normal flow of the reaction gas, but can efficiently cool the electrode plate.

It should also be explained that in a fuel cell, at least the flow field region 120 of the plate is in contact with the membrane electrode. During the reaction, the reactant gas passes through the flow field region 120 and contacts the membrane electrode, and is catalyzed to undergo chemical reaction to generate heat. Therefore, the region of the substrate 110 where the temperature is highest is the location of the flow field region 120. Because the coolant flows through the flow field region 120, on one hand, the flow channel of the flow field region 120 can be utilized to increase the contact area between the coolant and the polar plate, thereby better realizing heat dissipation, and on the other hand, the temperature of the polar plate can be efficiently reduced by cooling the main heating region of the polar plate.

To ensure the cooling effect, in an embodiment, referring to fig. 1 and 2, at least two third inlets 151 or at least two third outlets 152 are provided on the same side of the substrate 110. By increasing the number of inlets and outlets, the flow rate of coolant into the flow field region 120 can be increased, thereby ensuring a cooling effect. Further, at least two third inlets 151 or at least two third outlets 152 are spaced apart in the second direction, thereby improving the utilization rate of the substrate 110.

Optionally, the substrate 110 is further provided with a positioning hole 161.

In the process of preparing the polar plate by using the stamping process, the positioning holes 161 can be used for calibrating the position of each substrate 110 to be stamped, so as to ensure that the positions of the upstream field region 120 and each inlet and outlet of any substrate 110 are relatively consistent, thereby ensuring the dimensional accuracy of the polar plate and improving the yield of polar plate preparation.

When the fuel cell stack is assembled, the positioning holes 161 can be used for calibrating whether the positions of the two adjacent substrates 110 are consistent, so that the consistency of the stack is ensured, and the yield of the fuel cell preparation is improved.

After the fuel cell stack is assembled, a positioning member (e.g., a positioning pin) can be inserted into the positioning hole 161 to thereby fix the assembled fuel cell stack.

Optionally, a voltage inspection area 171 is further disposed on the substrate 110.

The voltage inspection area 171 may be integrally formed with the substrate 110. At this time, the voltage inspection region 171 is a part of the substrate 110. Referring to fig. 1, in the illustrated embodiment, the voltage inspection region 171 is a portion of the substrate 110 protruding outward from one side. In the process of bonding the substrate 110 to the membrane electrode, flowing the reaction gas, and generating the current, the current flows through the substrate 110. The external detection device is connected to the voltage inspection region 171, and can detect parameters such as current and voltage on the substrate 110, thereby confirming the reaction condition of the fuel cell.

In other embodiments, the voltage routing area 171 may be other conductive structures capable of connecting the external inspection device and the substrate 110. The voltage routing area 171 is used for conducting current, so that an operator can conveniently monitor the reaction of the fuel cell.

The application also provides a battery unit comprising two fuel cell plates 100A and 100B, a cathode side gas diffusion layer 1 and an anode side gas diffusion layer 2; the cathode-side gas diffusion layer 1 and the anode-side gas diffusion layer 2 are provided between the two fuel cell plates 100A and 100B.

It should be noted that the cathode-side gas diffusion layer 1 and the anode-side gas diffusion layer 2 are main structures constituting the membrane electrode of the fuel cell. Further, the anode-side gas diffusion layer 2 is provided with CCM (catalyst coated membrane, catalyst-coated membrane). The fuel gas (H ₂) reaches the catalyst layer through the anode-side gas diffusion layer 2, electrode reaction occurs under the action of the catalyst, electrons generated by the electrode reaction flow through an external circuit to reach the cathode through conduction of the catalyst layer, and hydrogen ions reach the cathode under the action of the proton exchange membrane. The oxygen gas passes through the cathode-side gas diffusion layer 1 and then reacts with hydrogen ions and electrons in the presence of a catalyst to produce water. Water is discharged through the cathode-side gas diffusion layer 1 and the anode-side gas diffusion layer 2.

In summary, the cathode-side gas diffusion layer 1 and the anode-side gas diffusion layer 2 can support a catalyst layer, stabilize an electrode structure, and also provide a gas channel, an electron channel, and a water drain channel for an electrode reaction.

Referring specifically to fig. 5 or 6, in the illustrated embodiment, one side of the cathode-side gas diffusion layer 1 contacts the electrode plate 100A, and the other side contacts the anode-side gas diffusion layer 2. The anode-side gas diffusion layer 2 contacts the cathode-side gas diffusion layer 1 on one side and the electrode plate 100B on the other side. At this time, the surface of the electrode plate 100A contacting the cathode-side gas diffusion layer 1 is for flowing the oxidizing gas therethrough, and the surface of the electrode plate 100B contacting the anode-side gas diffusion layer 2 is for flowing the fuel gas therethrough. Alternatively, the surface of the plate 100A facing away from the cathode-side gas diffusion layer 1 and the surface of the plate 100B facing away from the anode-side gas diffusion layer 2 may be provided for coolant to flow therethrough.

As can be seen from the foregoing, the flow field region 120 of the plate 100 for contacting the gas diffusion layer (either the cathode-side gas diffusion layer 1 or the anode-side gas diffusion layer 2) has a plurality of relatively raised ridges 121, with relatively recessed flow channels being formed between adjacent raised ridges 121. If the flow field 120 of the two plates 100A and 100B for contacting the gas diffusion layer is configured to be identical, the raised ridge 121 on the plate 100A faces the flow channel on the plate 100B with reference to fig. 5 after the plates 100A and 100B are stacked with the gas diffusion layer to form a cell. With this structure, when the fuel cell stack is compressed, the plate 100A is stressed, and the raised ridge 121 on the plate 100A can press the membrane electrode, but the plate 100B is a circulation channel corresponding to the position of the membrane electrode, and the circulation channel cannot support the membrane electrode. Therefore, the gas diffusion layer is easy to deform and even break due to unbalanced stress on the two sides of the membrane electrode, so that the structure of the fuel cell is damaged.

Thus, in one embodiment, the two plates 100A and 100B that make up the same cell have the flow field regions 120 that are offset in position in the second direction. In brief, the flow field region 120 of one of the plates is lower than the flow field region 120 of the other plate in the second direction. Thus, after the two electrode plates 100A and 100B are stacked with the gas diffusion layer to form a battery cell, referring to fig. 6, the raised ridge 121 on the electrode plate 100A is opposite to at least a portion of the raised ridge 121 on the electrode plate 100B. Under the structure, when the fuel cell stack is compressed, the electrode plate 100A is stressed, the raised ridges 121 on the electrode plate 100A squeeze the membrane electrode, meanwhile, at least part of the raised ridges 121 on the electrode plate 100B correspond to the position of the membrane electrode, at least part of the raised ridges 121 on the electrode plate 100B squeeze the membrane electrode, and the two ends of the membrane electrode are stressed, so that the state is stable.

Alternatively, after the two plates 100A and 100B are stacked with the gas diffusion layer to form a battery cell, the raised ridge 121 on either plate 100A faces one of the raised ridges 121 on plate 100B.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. A fuel cell plate (100) comprising a substrate (110), characterized in that the substrate (110) has a first face (111) and a second face (112), the first face (111) and the second face (112) being front and back with respect to each other;

Stamping the first face (111), forming a flow channel on the first face (111) recessed toward the second face (112), and forming a raised ridge (121) on the second face (112) raised away from the first face (111);

A circulation channel is formed between any two adjacent raised ridges (121) on the second surface (112);

the flow channels form a flow field region (120) for guiding the flow of the reactant gases;

-said first face (111) and said second face (112) each have said flow field region (120) thereon;

The substrate (110) is provided with:

a first inlet (131) provided on a first side of the flow field region (120) in a first direction;

a first outlet (132) disposed on a second side of the flow field region (120) along the first direction;

When the fuel cell plate (100) is used as a plate of a first reactant gas, the first reactant gas can enter the flow field region (120) through the first inlet (131), and can be discharged through the first outlet (132) after being guided by the flow field region (120);

a second inlet one (141) provided on a third side of the flow field region (120);

A second inlet (142) disposed on a second side of the flow field region (120) along the first direction, the number of second inlets (142) being less than the number of second inlets (141);

a second outlet (143) disposed along the first direction on a first side of the flow field region (120);

when the fuel cell plate (100) is used as a plate of a second reactant gas, the second reactant gas can enter the second inlet (142) through the first inlet (141), then enter the flow field region (120) through the second inlet (142), and pass through the flow field region (120) for guiding, and can be discharged through the second outlet (143);

Wherein the first outlet (132) and/or the second outlet (143) are/is connected to the second inlet (141) through a pipe, and water discharged through the first outlet (132) or the second outlet (143) acts on the second reaction gas in the second inlet (141) through the pipe.

2. The fuel cell plate (100) of claim 1, wherein any one of the flow channels extends in a first direction and a plurality of the flow channels are spaced apart in a second direction;

the first direction is perpendicular to the second direction.

3. The fuel cell plate (100) of claim 2, wherein the flow field region (120) further comprises first and second spacing ridges (122, 123) spaced apart along the second direction, the plurality of raised ridges (121) being disposed between the first and second spacing ridges (122, 123);

The width of the first limiting ridge (122) and the second limiting ridge (123) along the second direction is larger than the width of the protruding ridge (121) along the second direction.

4. The fuel cell plate (100) of claim 1, at least a portion of the first outlet (132) being below the flow field region (120);

And/or at least part of the second outlet (143) is lower than the flow field region (120).

5. The fuel cell plate (100) according to claim 1, wherein at least two second inlets (141) are provided on the substrate (110), and the at least two second inlets (141) are arranged side by side along the extending direction of the side edge of the corresponding flow field region (120);

And/or, at least two second inlets (142) are arranged on the substrate (110), and the at least two second inlets (142) are arranged side by side along the extending direction of the side edge of the corresponding flow field area (120);

And/or at least two second outlets (143) are arranged on the substrate (110), and the at least two second outlets (143) are arranged side by side along the extending direction of the side edge of the corresponding flow field area (120).

6. The fuel cell plate (100) of any of claims 1-5, wherein the substrate (110) is further provided with a third inlet (151) and a third outlet (152);

One of the third inlet (151) and the third outlet (152) is provided on a first side of the flow field region (120), and the other of the third inlet (151) and the third outlet (152) is provided on a second side of the flow field region (120);

Coolant can enter the flow field region (120) through the third inlet (151) and can be discharged through the third outlet (152).

7. The fuel cell plate (100) according to any one of claims 1 to 5, wherein the base plate (110) is further provided with positioning holes (161).

8. The fuel cell plate (100) of any of claims 1-5, wherein a voltage routing area (171) is further provided on the substrate (110).

9. A battery cell, characterized by comprising two fuel cell plates (100) according to any of claims 1-8, further comprising a cathode-side gas diffusion layer (1) and an anode-side gas diffusion layer (2);

the cathode-side gas diffusion layer (1) and the anode-side gas diffusion layer (2) are provided between the two fuel cell plates (100).

10. The cell of claim 9, wherein the flow field regions (120) of two of said fuel cell plates (100) are offset in position along the second direction.