Separator for fuel cell and fuel cell comprising it

Abstract

A separator for a fuel cell according to an embodiment of the present invention comprises a body plate and a meandering channel formed on one surface of the body plate, wherein the meandering channel comprises a first main channel formed with a first width, a second main channel formed with a second width spaced apart from the first main channel, and a bent channel having one end connected to the first main channel and the other end connected to the second main channel, and the first width may be larger than the second width. A fuel cell according to an embodiment of the present invention comprises a membrane-electrode assembly, a gas diffusion layer formed on at least one surface of the membrane-electrode assembly, and a separator that supplies gas to the gas diffusion layer, wherein the separator is a separator of any one of claims 1 to 8.

Description

Technology Field

[0001] The present invention relates to a separator for a fuel cell capable of improving current density and a fuel cell including the same. Background Technology

[0002] Polymer Electrolyte Membrane Fuel Cells (PEMFCs) generate electricity in the process where hydrogen supplied to the anode is ionized, passes through the electrolyte membrane, and is reduced by oxygen at the cathode to produce water molecules.

[0003] When a limited amount of fuel or oxidant (hereinafter referred to as "gas") is supplied, the amount of power produced by the fuel cell is proportional to the current density of the fuel cell, and the current density is improved as the loss is reduced or as the supplied gas is delivered uniformly over all areas during the process of reaching the membrane electrode assembly (MEA).

[0004] In contrast, if the gas supplied through the inlet of the separator does not reach the membrane-electrode assembly smoothly, the current density decreases, leading to a problem where the performance of the fuel cell is reduced. Prior art literature

[0005] Korean Published Patent No. 2023-0007244 A (2023.01.12.) The problem to be solved

[0006] To solve the above problem, the present invention aims to provide a separator for a fuel cell and a fuel cell including the same, which can improve the current density of the fuel cell by facilitating gas convection between adjacent flow paths within the separator and gas diffusion into the gas diffusion layer. means of solving the problem

[0007] A separator for a fuel cell according to an embodiment of the present invention comprises a body plate and a meandering channel formed on one surface of the body plate, wherein the meandering channel comprises a first main channel formed with a first width, a second main channel formed with a second width spaced apart from the first main channel, and a bent channel having one end connected to the first main channel and the other end connected to the second main channel, and wherein the first width may be larger than the second width.

[0008] A separator for a fuel cell according to an embodiment of the present invention may further include a rib surrounded by the first main flow path, the second main flow path, and the folded flow path.

[0009] In a separator for a fuel cell according to an embodiment of the present invention, the first main flow path and the second main flow path may be alternately arranged along one direction.

[0010] In a separator for a fuel cell according to an embodiment of the present invention, the meandering channels are provided in plurality, and the first main channel of one of the pair of adjacent meandering channels may be alternately arranged with the second main channel of the other meandering channel.

[0011] A separator for a fuel cell according to an embodiment of the present invention may further include a first flow path assembly and a second flow path assembly, each comprising the plurality of meandering flow paths.

[0012] In a separator for a fuel cell according to an embodiment of the present invention, the first flow path assembly and the second flow path assembly may be symmetrical to each other.

[0013] In a separator for a fuel cell according to an embodiment of the present invention, the arrangement order of the first main flow path and the second main flow path of the first flow path assembly may be opposite to the arrangement order of the first main flow path and the second main flow path of the second flow path assembly.

[0014] In a separator for a fuel cell according to an embodiment of the present invention, the meandering flow path may further include a deformation section in which the width of the first main flow path decreases to a second width or the width of the second main flow path increases to a first width.

[0015] A fuel cell according to an embodiment of the present invention comprises a membrane-electrode assembly, a gas diffusion layer formed on at least one surface of the membrane-electrode assembly, and a separator that supplies gas to the gas diffusion layer, wherein the separator is a separator of any one of claims 1 to 8. Effects of the invention

[0016] As described above, the fuel cell separator according to the embodiment of the present invention and the fuel cell including the same facilitate gas convection between adjacent flow paths within the separator and gas diffusion into the gas diffusion layer, thereby improving the current density of the fuel cell. Brief explanation of the drawing

[0017] Figure 1 is an exploded perspective view showing a polymer electrolyte fuel cell. FIG. 2a is a front view of a separator plate according to a first embodiment of the present invention. FIG. 2b is a cross-sectional view showing a cross-section on the yz plane of region A in FIG. 2a. FIG. 3 is a front view of a separator plate according to a second embodiment of the present invention. Figure 4 is a graph comparing the average pressure difference of the flow path within the separator plate for the second embodiment and the conventional one. FIG. 5a is a diagram comparing the gas flow rate in the gas diffusion layer for the second embodiment and the conventional one. Figure 5b is a graph comparing the flow velocities of Figure 5a numerically. FIG. 6a is a diagram comparing the current density of the second embodiment with that of the conventional one. Figure 6b is a graph comparing the current densities of Figure 6a numerically. FIG. 7 is a front view of a separator plate according to a third embodiment of the present invention. FIG. 8a is a diagram comparing the gas flow rate in the gas diffusion layer for the third embodiment and the conventional one. Figure 8b is a graph comparing the flow velocities of Figure 8a numerically. FIG. 9a is a diagram comparing the current density of the third embodiment with that of the conventional one. Figure 9b is a graph comparing the current densities of Figure 9a numerically. FIG. 10 is a front view of a separator plate according to a fourth embodiment of the present invention. Specific details for implementing the invention

[0018] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0019] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this invention, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that in the accompanying drawings, identical components are indicated by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that may obscure the essence of the present invention will be omitted. For the same reason, some components in the accompanying drawings may be exaggerated, omitted, or schematically depicted.

[0021] First, the x, y, and z directions described in this specification will be explained with reference to FIG. 2a.

[0022] Referring to FIG. 2a, the x direction indicates the direction in which gas flows along the main flow path (3211, 3212) in the plane of the separator plate (3000).

[0023] The y-direction means a direction from one main flow path (3211, 3212) to another main flow path (3211, 3212) on the plane of the separator plate (3000), which is orthogonal to the x-direction.

[0024] The z direction is the direction of coming out of or going into the plane of the separator plate (3000), the +z direction is the direction from the separator plate (3000) toward the gas diffusion layer (2000, see FIG. 2b), and the -z direction is the direction away from the gas diffusion layer (2000, see FIG. 2b).

[0025] Hereinafter, a fuel cell to which a separator plate according to the first embodiment of the present invention is applied will be described.

[0026] Figure 1 is an exploded perspective view showing a polymer electrolyte fuel cell.

[0027] As shown in FIG. 1, the fuel cell (10) includes a plurality of unit cells (100) and end plates (510, 520).

[0028] The unit cell (100) may include a membrane-electrode assembly (1000), a gas diffusion layer (2000), and a separator (3000).

[0029] The membrane-electrode assembly (1000) is made of a conventional structure including an electrolyte membrane (not shown), an anode (not shown), and a cathode (not shown).

[0030] The electrolyte membrane (not shown) is a polymer electrolyte formed with a thickness of approximately 5 μm to 200 μm and has an ion exchange function that moves hydrogen ions generated at the anode (not shown) to the cathode (not shown). In this embodiment, the fuel cell (10) is exemplified as being composed of a polymer electrolyte fuel cell, but the present invention is not limited thereto and can be applied to various types of fuel cells.

[0031] A gas diffusion layer (2000) is formed on at least one surface of a membrane-electrode assembly (1000) and can be disposed between a separator plate (3000) and a membrane-electrode assembly (1000). The gas diffusion layer (2000) may be a passage for transferring gas from the separator plate (3000) to the membrane-electrode assembly (1000).

[0032] To this end, the gas diffusion layer (2000) may have a porous structure that allows gas to pass through and may be made of a conductive material to act as a current conductor between the separator (3000) and the membrane-electrode assembly (1000) described later. For example, the gas diffusion layer (2000) may be made of a porous conductive material such as carbon paper (carbon cloth and paper) or metal foam (metal foam and fiber).

[0033] A separator plate (3000) is disposed on at least one surface of the gas diffusion layer (2000) and has a flow path through which gas flows to supply gas to the gas diffusion layer (2000).

[0034] The more active the convection of gas between adjacent channels within the separator (3000) or the more active the diffusion of gas into the gas diffusion layer (2000), the higher the current density of the fuel cell (10) can be.

[0035] To this end, the fuel cell (10) includes a separator plate for the fuel cell (hereinafter, 'separator plate', 3000) according to the first to fourth embodiments, and the separator plate (3000) according to the first to fourth embodiments discloses a flow path structure capable of improving current density, and details will be described later.

[0036] Meanwhile, a plurality of unit cells (100) are stacked between end plates (510, 520) disposed on the outer side of the unit cells (100).

[0037] A pair of end plates (510, 520) may be spaced apart and positioned opposite each other on the same axis, and one end plate (510) may have a fuel supply port (not shown) and a fuel exhaust port (not shown) formed therein for supplying or exhausting fuel, and the other end plate (520) may have an oxidizer supply port (not shown) and an oxidizer exhaust port (not shown) formed therein for supplying or exhausting an oxidizer.

[0038] Fuel supplied to one end plate (510) through a fuel supply port (not shown) can be supplied to the anode (not shown) of a membrane-electrode assembly (1000) by passing through a separator plate (3000) and a gas diffusion layer (2000), and oxidizer supplied to the other end plate (520) through an oxidizer supply port (not shown) can be supplied to the cathode (not shown) of a membrane-electrode assembly (1000) by passing through a separator plate (3000) and a gas diffusion layer (2000).

[0039] Here, the fuel may consist of hydrogen gas or a hydrocarbon fuel containing hydrogen, and the oxidizer may consist of air containing oxygen gas or pure oxygen, and in this specification, the fuel and the oxidizer are collectively referred to as gas.

[0040] Meanwhile, the end plates (510, 520) may include a current collector plate for collecting current and an insulating plate for insulation.

[0041] Hereinafter, a separator plate according to the first embodiment of the present invention will be described.

[0042] FIG. 2a is a front view of a separator according to a first embodiment of the present invention, and FIG. 2b is a cross-sectional view showing a cross-section on the yz plane of region A in FIG. 2a. At this time, the separator (3000) shown in FIG. 2a and FIG. 2b may be a cathode (reduction electrode) side separator (3000).

[0043] As shown in FIG. 2a, the separator plate (3000) may include a body plate (3100), a meandering channel (3210), and a rib (3300).

[0044] The body plate (3100) may be in the shape of a thin flat plate and may be disposed between a gas diffusion layer (2000, see FIG. 1) and an end plate (510, see FIG. 1), or between a plurality of gas diffusion layers (2000).

[0045] The body plate (3100) may be made of stainless steel, titanium, and aluminum, which possess excellent electrical and thermal conductivity, corrosion resistance, and sufficient rigidity to serve as a structural support. However, the shape and material of the body plate (310) are not limited to these, and various shapes and materials may be used.

[0046] An inlet (3110) for gas to be introduced may be formed on one side of the body plate (3100), and an outlet (3130) for gas to be discharged may be formed on the other side.

[0047] The meandering channel (3210) is a channel through which gas flows and can be formed to connect the inlet (3110) and the outlet (3130) on one side of the body plate (3100).

[0048] The meandering channel (3210) is formed to be recessed to a predetermined depth on one side of the body plate (3100). It may be formed by being cast integrally with the body plate (3100) or by being processed in the form of an intaglio on an already cast body plate (3100).

[0049] The meandering path (3210) may include a bending path (3213) formed to be bent multiple times, and a first main path (3211) and a second main path (3212) formed not to be bent.

[0050] Some of the gas flowing through the meandering path (3210) may diffuse into the gas diffusion layer (2000) or convection may occur across the rib (3300) to another adjacent path within the separator (3000).

[0051] Referring to FIG. 2b, the fact that gas diffuses from the separator plate (3000) to the gas diffusion layer (2000) means that some of the gas flowing through the meandering path (3210) moves to the gas diffusion layer (2000) positioned in the +z direction.

[0052] As the diffusion of gas becomes smoother, the gas supply to the membrane-electrode assembly (1000) becomes smoother, so the current density of the fuel cell (10, see FIG. 1) can be improved.

[0053] In addition, the fact that gas convection occurs in an adjacent flow path means that gas moves from one flow path to another adjacent flow path by bypassing the rib (3300).

[0054] For example, it means that some of the gas passing through the second main channel (3212) diffuses into the gas diffusion layer (2000) positioned in the +z direction, then bypasses the rib (3300) and moves in the ±y direction, and then moves again in the -z direction to the adjacent first main channel (3211).

[0055] In this way, convection to adjacent channels is accompanied by the diffusion of gas into a gas diffusion layer (2000), and some of the gas diffused during the convection process can be supplied to the membrane-electrode assembly (1000) separately from the previously diffused gas, thus contributing to an improvement in current density.

[0056] Since the meandering flow path (3210) is bent multiple times to form a long flow path, the residence time and contact area of ​​the gas are increased, thereby improving the diffusion effect to the gas diffusion layer (2000) or the convection effect to the adjacent flow path.

[0057] Again, referring to FIG. 2a, the first main channel (3211) is formed to extend in the x-direction and can be formed with a first width (W1).

[0058] The second main channel (3212) is formed extending in the x-direction, spaced apart from the first main channel (3211), and can be formed with a second width (W2).

[0059] At this time, the first width (W1) is formed to be larger than the second width (W2), and specifically, the first width (W1) can be formed at a ratio of more than 1 time and less than or equal to 2 times the second width (W2). For example, if the second width (W2) is 0.8 mm, the first width (W1) can be formed to be greater than 0.8 mm and less than or equal to 1.6 mm.

[0060] The first main channel (3211) and the second main channel (3212) can be connected to a bending channel (3213) at one end and can be positioned opposite each other with the bending channel (3213) in between, so that the direction of the air passing through the first main channel (3211) and the direction of the air passing through the second main channel (3212) may be opposite.

[0061] The first main flow path (3211) and the second main flow path (3212) are formed with a longer flow path length than the folded flow path (3213), so that the gas can stay longer than in the folded flow path (3213), and thus the gas supply to the gas diffusion layer (2000) can be smoother than in the folded flow path (3213).

[0062] Referring to FIG. 2a, the meandering channel (3210) may have a first main channel (3211) with a width of 1 width (W1) and a second main channel (3212) with a width of 2 width (W2) arranged alternately along one direction.

[0063] For example, the structure may have a first main channel (3211) first arranged at the top of the +y direction to be connected to the inlet (3110), and a second main channel (3212) with a narrow width and a first main channel (3211) with a wide width alternately arranged in the -y direction.

[0064] Assuming that the depth of the first main channel (3211) and the second main channel (3212) is the same, the pressure of the gas passing through the channel is greater in the second main channel (3212) than in the first main channel (3211), so a pressure difference occurs between the first main channel (3211) and the second main channel (3212).

[0065] Therefore, when the first main flow path (3211) and the second main flow path (3212) are alternately arranged adjacently, a convection phenomenon can be activated in which gas moves from one flow path over the rib (3300) to another adjacent flow path due to the pressure difference.

[0066] In this process, the gas passes through a gas diffusion layer (2000) positioned in the +z direction of the body plate (3100), so the amount of gas supplied to the gas diffusion layer (2000) increases, and the current density of the fuel cell (10, see FIG. 1) can be improved.

[0067] Meanwhile, in FIG. 2a, the meandering channel (3210) is depicted as having the first main channel (3211) connected to the inlet (3110) at the top of the +y direction, but it is not limited to the above example, and the second main channel (3212) may be connected to the inlet (3110) at the top of the +y direction.

[0068] One end of the bending path (3213) is connected to the first main path (3211), and the other end is connected to the second main path (3212), so that it can be formed to be bent between the first main path (3211) and the second main path (3212).

[0069] Referring to FIG. 2a, the bending channel (3213) may be positioned perpendicularly to the first main channel (3211) and the second main channel (3212), but is not limited to the above shape and may be positioned obliquely by forming an acute angle between the first main channel (3211) and the second main channel (3212), or may be positioned in the shape of an arc with curvature.

[0070] When the bending channel (3213) is not perpendicular to the main channel (3211, 3212) but is arranged in a slanted or curved shape, the gas moving from the first main channel (3211) to the bending channel (3213) and the gas moving from the bending channel (3213) to the second main channel (3212) can maintain a higher speed with reduced loss of momentum, so that diffusion or convection into the gas diffusion layer (200) can be more active.

[0071] The bending channel (3213) may be formed with a first width (W1) or a second width (W2), or alternatively, may be formed with any width.

[0072] The rib (3300) is a part of the body plate (3100) and may be formed at the same height as the surface of the body plate (3100) or may be formed protruding in the +z direction from the surface of the body plate (3100).

[0073] The rib (3300) is formed in a shape surrounded by the first main flow path (3211), the second main flow path (3212), and the folded flow path (3213), so as to divide the boundaries of each flow path.

[0074] Hereinafter, a separator plate according to the second embodiment of the present invention will be described.

[0075] FIG. 3 is a front view of a separator plate according to a second embodiment of the present invention.

[0076] The second embodiment is identical to the first embodiment described above, except that the first main channel (3211) and the second main channel (3212) are alternately arranged in a plurality of meandering channels (3210); therefore, a redundant description of the same configuration is omitted.

[0077] Additionally, the term "meandering path" (3210) below refers to a single meandering path (3210) that is connected without interruption from the inlet (3110) to the outlet (3130).

[0078] Referring to FIG. 3, the meandering channels (3210) of the separator plate (3000) may be provided in multiple numbers, and the multiple meandering channels (3210) may be arranged so as not to intersect each other.

[0079] At this time, the first main channel (3211) of one of the adjacent pair of meandering channels (3210) can be alternately arranged with the second main channel (3212) of the other meandering channel (3210).

[0080] That is, in any single meandering path (3210) among the multiple meandering paths (3210), the first main path (3211) and the second main path (3212) can be arranged alternately, and the structure in which the first main path (3211) and the second main path (3212) are arranged alternately throughout the multiple meandering paths (3210) can also be satisfied.

[0081] As mentioned above, the pressure of the gas passing through the Euro is greater in the second main Euro (3212) than in the first main Euro (3211).

[0082] In addition, even within a single channel, the wider the channel, the smaller the pressure drop along the direction of flow, and the narrower the channel, the greater the pressure drop.

[0083] In summary, the gas supplied to the inlet (3110) at the same pressure has a higher initial pressure when passing through the second main channel (3212) than when passing through the first main channel (3211), but as it flows through the channel, the pressure decreases more significantly in the second main channel (3212), so eventually the pressure in the second main channel (3212) can become lower than the pressure in the first main channel (3211).

[0084] Accordingly, the pressure difference between the adjacent second main channel (3212) and the first main channel (3211) gradually decreases along the flow direction while having a positive value, becomes zero at one point, and downstream of that point, the magnitude of the pressure difference increases while having a negative value.

[0085] As described above, when the pressure difference between the adjacent first main flow path (3211) and the second main flow path (3212) increases, the convection effect becomes active, increasing the amount of gas supplied to the gas diffusion layer (2000), and thus the current density of the fuel cell (10) can be improved.

[0086] In addition, as the contact area of ​​the gas is widened as the multiple meandering channels (3210) are provided, the degree of gas diffusion from the separator plate (3000) to the gas diffusion layer (2000) can be improved.

[0087] Meanwhile, in FIG. 3, the inlet (3110) and the outlet (3130) are each shown as being connected to four meandering channels (3210), but this is not limited to the above example, and an even number of meandering channels, such as two or six, may be connected.

[0088] Additionally, in FIG. 3, the meandering channel (3210) is depicted as being first positioned so that the second main channel (3212) is connected to the inlet (3110) at the top of the +y direction, but it is not limited to the above example, and the first main channel (3211) may be first positioned so that it is connected to the inlet (3110) at the top of the +y direction.

[0089] Hereinafter, the effects of the separator plate according to the second embodiment of the present invention will be described.

[0090] FIG. 4 is a graph comparing the average pressure difference of the flow path within the separator plate for the second embodiment and the conventional one, FIG. 5a is a graph comparing the gas flow velocity in the gas diffusion layer for the second embodiment and the conventional one, and FIG. 5b is a graph comparing the flow velocity of FIG. 5a numerically. FIG. 6a is a graph comparing the current density for the second embodiment and the conventional one, and FIG. 6b is a graph comparing the current density of FIG. 6a numerically.

[0091] In FIGS. 4 to 6b, (a) refers to a conventional separator plate with a uniform width of 1 mm, and (b) refers to a separator plate (3000) according to a second embodiment of the present invention.

[0092] Referring to FIG. 4, the average pressure difference of the flow path within the separator plate is 89.74 Pa for the conventional separator plate (a) with a uniform flow path width and 116.18 Pa for the separator plate (b) according to the second embodiment, confirming that the separator plate (b) according to the second embodiment is improved by 29.5%p compared to the conventional separator plate (a).

[0093] When the pressure difference between the channels increases, the convection of gas between adjacent channels in the separator (3000) can become active, and since the degree of convection can be confirmed by flow velocity (speed) data that can express the momentum of the gas, the flow velocity of the gas diffusion layer (2000) is compared with reference to FIGS. 5a and FIGS. 5b below.

[0094] Referring to FIG. 5a, it can be seen that the flow rate of the gas diffusion layer (2000) is faster when the separator plate (b) according to the second embodiment is applied than when the conventional separator plate (a) is applied.

[0095] Referring to Fig. 5b, which is a numerical comparison of Fig. 5a, it can be seen that the average speed in the y direction is improved by 36%p and the average speed in the z direction is improved by 62%p when the separator plate (b) according to the second embodiment is applied compared to when the conventional separator plate (a) is applied.

[0096] In summary, in the case of the separator plate (b) according to the second embodiment, the pressure difference between the flow paths within the separator plate (3000) increases compared to the conventional separator plate (a). As a result, the convection of gas between adjacent main flow paths (3211, 3212) with different widths is active, which can be seen through the increase in the flow velocity in the y direction, and the diffusion of gas from the separator plate (3000) to the gas diffusion layer (2000) is smooth, which can be seen through the increase in the flow velocity in the z direction.

[0097] As convection and diffusion become more active, more gas is supplied to the membrane-electrode assembly (1000, see FIG. 1), and as a result, the current density can be improved. This is explained by referring to FIG. 6a, which compares the current density of the second embodiment with that of the conventional one, and FIG. 6b, which compares FIG. 6a numerically.

[0098] Referring to FIG. 6a, it can be seen that the current density is generally higher when using the separator (b) according to the second embodiment compared to when using the conventional separator (a).

[0099] Specifically, referring to FIG. 6b, when using a conventional separator (a), the current density is 0.667 A / cm² 2 And, when using the separator (b) according to the second embodiment, the current density is 0.673 A / cm², which is 0.85%p improved compared to the conventional method. 2 It can be confirmed that it is.

[0100] Hereinafter, a separator plate according to the third embodiment of the present invention will be described.

[0101] FIG. 7 is a front view of a separator plate according to a third embodiment of the present invention.

[0102] The third embodiment is identical to the aforementioned second embodiment except that it further includes a first Euro assembly (3201) and a second Euro assembly (3202), so a redundant description of the same configuration is omitted.

[0103] Referring to FIG. 7, the separator plate (3000) may further include a first flow path assembly (3201) and a second flow path assembly (3202), each comprising a plurality of meandering flow paths (3210).

[0104] At this time, the first flow path assembly (3201) including a plurality of meandering flow paths (3210) is formed as in the second embodiment, and the second flow path assembly (3202) can be formed symmetrically with respect to the first flow path assembly (3201).

[0105] For example, a first flow path assembly (3201) including a plurality of meandering flow paths (3210) is positioned on the left side, and a second flow path assembly (3202) formed symmetrically thereto is positioned on the right side, so that the meandering flow paths (3210) in the body plate (3100) can be arranged in two stages on the left and right.

[0106] In this case, the first main flow path (3211) and the second main flow path (3212) belonging to the first flow path assembly (3201) and the second flow path assembly (3202) may be formed with a shorter flow path length than the first main flow path (3211) and the second main flow path (3212) of the aforementioned embodiments.

[0107] Accordingly, since the gas flows through the shorter first main path (3211) and second main path (3212), the pressure drop can be reduced compared to the embodiments described above.

[0108] Therefore, the gas can flow through the first main channel (3211) and the second main channel (3212) while maintaining a higher pressure and diffuse into the gas diffusion layer (2000).

[0109] In addition, since the first Euro assembly (3201) and the second Euro assembly (3202) have the first main Euro (3211) and the second main Euro (3212b) arranged alternately, the convection effect can be active due to the pressure difference between the Euros.

[0110] Meanwhile, the length of the first main flow path (3211) and the second main flow path (3212) connecting the inlet (3110) and the second flow path assembly (3202) can be formed long, and the length of the first main flow path (3211) and the second main flow path (3212) connecting the outlet (3130) and the first flow path assembly (3201) can also be formed long.

[0111] However, even at this time, the Euro assembly (3201, 3202) may have the first main Euro (3211) and the second main Euro (3212) arranged alternately.

[0112] The effects of the separator plate according to the third embodiment of the present invention will be described below.

[0113] FIG. 8a is a diagram comparing the gas flow rate in the gas diffusion layer for the third embodiment and the conventional method, and FIG. 8b is a graph comparing the flow rates of FIG. 8a numerically. FIG. 9a is a diagram comparing the current density for the third embodiment and the conventional method, and FIG. 9b is a graph comparing the current densities of FIG. 9a numerically.

[0114] In FIGS. 8a to 9b, (a) refers to a conventional separator plate with a uniform width of 1 mm, and (c) refers to a separator plate (3000) according to a third embodiment of the present invention.

[0115] Since the effect according to the third embodiment is identical to the effect according to the second embodiment except for specific numerical values, a redundant description of the same effect is omitted.

[0116] Referring to FIG. 8a, it can be seen that the flow rate of the gas diffusion layer (2000) is generally faster when the separator plate (c) according to the third embodiment is applied than when the conventional separator plate (a) is applied.

[0117] Referring to Fig. 8b, which is a numerical comparison of Fig. 8a, it can be seen that the average speed in the y direction is improved by 79.4%p and the average speed in the z direction is improved by 137.9%p compared to the case where the separator plate (c) according to the third embodiment is applied and the conventional separator plate (a) is applied.

[0118] It can be seen that the convection of gas between adjacent parallel channels (3211a, 3211b) of different widths is active and that the diffusion of gas from the separator plate (3000) to the gas diffusion layer (2000) is smooth through the significant increase in the flow velocity in the y direction and the flow velocity in the z direction.

[0119] Referring to FIG. 9a, it can be seen that the current density is generally higher when using the separator (c) according to the third embodiment compared to when using the conventional separator (a).

[0120] Specifically, referring to FIG. 9b, when using a conventional separator (a), the current density is 0.667 A / cm² 2 And, when using the separator (c) according to the third embodiment, the current density is 0.681 A / cm², which is 2.04%p improved compared to the conventional method. 2 It can be confirmed that it is.

[0121] Hereinafter, a separator plate according to the fourth embodiment of the present invention will be described.

[0122] FIG. 10 is a front view of a separator plate according to a fourth embodiment of the present invention.

[0123] Since the fourth embodiment is identical to the aforementioned third embodiment except that the arrangement of the second Euro assembly (3202) is changed and a deformation section (3214) is further included, a redundant description of the same configuration is omitted.

[0124] Referring to FIG. 10, the arrangement order of the first main euro (3211) and the second main euro (3212) of the first euro assembly (3201) may be opposite to the arrangement order of the first main euro (3211) and the second main euro (3212) of the second euro assembly (3202).

[0125] Specifically, if the multiple meandering channels (3210) of the first channel assembly (3201) are arranged from the second main channel (3212) at the top of the +y direction within the area of ​​the first channel assembly (3201) and the first main channel (3211) is arranged alternately in the -y direction, the multiple meandering channels (3210) of the second channel assembly (3202) are arranged in the opposite way from the first main channel (3211) and the second main channel (3212) can be arranged alternately in the -y direction.

[0126] According to the above structure, the first main flow path (3211) of the first flow path assembly (3201) can be placed side by side with the second main flow path (3212) of the second flow path assembly (3202) at the same y-value, and since the second main flow path (3212) of the first flow path assembly (3201) can be placed side by side with the first main flow path (3211) of the second flow path assembly (3202) at the same y-value, a pressure difference can be created between the first flow path assembly (3201) and the second flow path assembly (3202), thereby enabling active convection between adjacent main flow paths (3211, 3212) in the x-direction.

[0127] Meanwhile, the meandering Euro (3210) may further include a deformation section (3214).

[0128] The deformation section (3214) may be a section in which the width of the first main flow path (3211) or the second main flow path (3212) is reduced to the second width (W2) or the width of the second main flow path (3212) is increased to the first width (W1).

[0129] Specifically, the deformation section (3214) may be placed in the first main flow path (3211) and the second main flow path (3212) connecting the inlet (3110) and the second flow path assembly (3202), and may be placed in the first main flow path (3211) and the second main flow path (3212) connecting the outlet (3130) and the first flow path assembly (3201).

[0130] The first main flow path (3211) can become the second main flow path (3212) by passing through the deformation section (3214) and the second main flow path (3212) can become the first main flow path (3211) by passing through the deformation section (3214) and increasing in width.

[0131] When including a deformation section (3214) in which the width changes as described above, even if the second Euro assembly (3202) is arranged in the opposite order to the first Euro assembly (3201), the multiple meandering Euros (3210) can satisfy a structure in which the first main Euro (3211) and the second main Euro (3212) are arranged alternately.

[0132] Although embodiments of the present invention have been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention. Explanation of the symbols

[0133] 10 : Fuel cell 2000 : Gas diffusion layer 3000: Separator plate 3100: Body plate 3110 : Inlet 3130 : Outlet 3210: Meandering Euro 3211: 1st Main Euro 3212: 2nd Main Euro 3213: Bending Euro 3300 : Liv

Claims

Claim 1 A separator for a fuel cell comprising: a body plate; and a meandering channel formed on one surface of the body plate, wherein the meandering channel comprises: a first main channel formed with a first width; a second main channel formed with a second width spaced apart from the first main channel; and a bent channel having one end connected to the first main channel and the other end connected to the second main channel, wherein the first width is greater than the second width, and the first main channel and the second main channel are alternately arranged along one direction. Claim 2 A separator for a fuel cell according to claim 1, further comprising a rib surrounded by the first main flow path, the second main flow path, and the folded flow path. Claim 3 delete Claim 4 A separator for a fuel cell according to claim 1, wherein the meandering channels are provided in plurality, and the first main channel of one of the adjacent pair of meandering channels is alternately arranged with the second main channel of the other meandering channel. Claim 5 A separator for a fuel cell according to claim 4, further comprising a first flow path assembly and a second flow path assembly, each comprising the plurality of meandering flow paths. Claim 6 In claim 5, the first Euro assembly and the second Euro assembly are symmetrical to each other, forming a separator for a fuel cell. Claim 7 A separator for a fuel cell according to claim 5, wherein the arrangement order of the first main flow path and the second main flow path of the first flow path assembly is opposite to the arrangement order of the first main flow path and the second main flow path of the second flow path assembly. Claim 8 A separator for a fuel cell according to claim 7, wherein the meandering path further includes a deformation section in which the width of the first main path decreases to a second width or the width of the second main path increases to a first width. Claim 9 A fuel cell comprising: a membrane-electrode assembly; a gas diffusion layer formed on at least one surface of the membrane-electrode assembly; and a separator that supplies gas to the gas diffusion layer, wherein the separator is a separator of any one of claims 1, 2, 4 to 8.

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