Metal separator

Abstract

The present application relates to a metal separator, a fuel cell comprising the metal separator, and a fuel cell stack comprising the fuel cell. According to the metal separator of the present application, it is possible to secure airtightness while preventing deformation of manifold inlet-and-outlet holes, and to uniformly distribute the flow rate of an injected and discharged reaction gas.

Description

metal separator

[0001] The present application relates to a metal separator, a fuel cell cell including the metal separator, and a fuel cell stack including the fuel cell cell.

[0002] Recently, to combat global warming, powertrains are shifting from internal combustion engines (ICEs) to electric vehicles (EVs) and hydrogen fuel cell vehicles (FCEVs). Fuel cells used in FCEVs not only power industrial, household, and vehicular applications, but also power small electronic devices such as portable devices. Their applications are expanding as a highly efficient, clean energy source, contributing to both energy conservation and environmental protection.

[0003] A hydrogen fuel cell is a type of power generation device that converts the chemical energy of fuel into electrical energy through an electrochemical reaction within a stack. It generates power by utilizing the energy generated during the reaction between hydrogen and oxygen. Specifically, a hydrogen fuel cell can use hydrogen gas as fuel, and the oxidation of hydrogen gas produces hydrogen ions (protons) and electrons. These hydrogen ions and electrons then undergo an electrochemical reaction with oxygen in the air, producing water and generating electrical energy from the electron flow.

[0004] These hydrogen fuel cells consist of a metal separator, a gas diffusion layer (GDL), and a membrane electrode assembly. In particular, the metal separator, along with the gas diffusion layer and membrane electrode assembly, is a key component of the fuel cell stack. It separates hydrogen, oxygen, and coolant, evenly distributing and supplying them across the entire membrane electrode assembly, and collects (anode) and transmits (cathode) the current generated by the electrochemical reaction.

[0005] Metal separators are formed with gasket lines on their surfaces to maintain a seal, preventing the hydrogen, oxygen, and coolant flowing through the passage from leaking to other areas. However, metal separators are very thin sheets of material. If the gasket lines are not optimized, the pressure applied when stacking multiple cells can cause deformation of the manifold inlet / outlet holes of the metal separator, or the sub-gasket lines can not be pressed relatively tightly, resulting in gaps in the middle of the sub-gasket lines. Deformation of the manifold inlet / outlet holes or the formation of gaps in the middle of the sub-gasket lines can make it difficult to ensure airtightness. Therefore, to solve these problems, a metal separator with a gasket shape that can prevent deformation of the manifold inlet / outlet holes while simultaneously ensuring airtightness is required.

[0006] The object of the present application is to provide a metal separator that can prevent deformation of a manifold inlet / outlet hole, secure airtightness, and evenly distribute the flow rate of injected and discharged reaction gas.

[0007] In order to solve the above problem, the metal separator of the present application comprises a metal separator body and a gasket line formed on the surface of at least one surface of the metal separator body, wherein the metal separator body comprises a reaction surface including a reaction channel, a cooling surface located opposite the reaction surface and including a cooling channel, a manifold section including at least one pair of first reaction gas manifolds formed on both sides of each of the reaction channel and the cooling channel and penetrating the reaction surface and the cooling surface, at least one pair of cooling water manifolds and at least one pair of second reaction gas manifolds, and a plurality of manifold inlet and outlet holes formed between each of the reaction channel and the cooling channel and penetrating the reaction surface and the cooling surface, wherein the gasket line surrounds the entire periphery of each of the at least one pair of first reaction gas manifolds, the at least one pair of cooling water manifolds and the at least one pair of second reaction gas manifolds, or .... A manifold gasket line surrounding the entire perimeter of each of the manifold and the one or more pairs of second reaction gas manifolds, a flow gasket line connected to the manifold gasket line and surrounding the reaction flow path and the plurality of manifold inlet and outlet holes, or surrounding the cooling flow path and the one or more pairs of cooling water manifolds, and a plurality of support gasket lines extending from the manifold gasket line located at the inner perimeter of each of the one or more pairs of second reaction gas manifolds toward the reaction flow path, or each of the one or more pairs of second reaction gas manifolds, and formed between the plurality of manifold inlet and outlet holes, wherein the support gasket lines satisfy the following general formula 1.

[0008] [General Formula 1]

[0009] (B-(B×0.5))2 ≤ D ≤ (B+(B×0.5))2

[0010] In the above general formula 1, D is the length of the gasket line, and B is the width of the manifold gasket line.

[0011] The above manifold gasket line may have a width of 2 mm to 5 mm.

[0012] Additionally, the gasket line may include fluorocarbon rubber (FKM), ethylene propylene diene terpolymer (EPDM), or vinyl methyl silicone rubber (LSR).

[0013] Additionally, a plurality of support gasket lines may be formed by extending from the manifold gasket lines positioned on the inner edge of each of the one or more pairs of first reaction gas manifolds toward the reaction path, or toward each of the one or more pairs of first reaction gas manifolds.

[0014] Additionally, the gasket line may be formed on the surface of the reaction surface and the cooling surface of the metal separator body, or may be formed on the surface of the reaction surface of the metal separator body and not formed on the surface of the cooling surface.

[0015] Additionally, the metal separator body may be a base material made of stainless steel, titanium, aluminum, magnesium or an alloy thereof.

[0016] In addition, the metal separator body may further include a diffusion path that is connected to each of the reaction path and the cooling path and extends toward a plurality of manifold inlet and outlet holes.

[0017] In addition, the metal separator may further include a metal coating layer formed on the surface of the metal separator body, or the surface of the metal separator body having the gasket line formed on the surface; or a surface modification layer.

[0018] In addition, the fuel cell of the present application includes a membrane electrode assembly surrounded by a sub-gasket line; and a pair of metal separators each of which is laminated with reaction surfaces facing the lower and upper portions of the membrane electrode assembly, such that the sub-gasket line is in contact with the support gasket line.

[0019] In addition, the metal separator disposed at the bottom of the membrane electrode assembly may be a hydrogen electrode metal separator, and the metal separator disposed at the top of the membrane electrode assembly may be an air electrode metal separator.

[0020] In addition, the hydrogen electrode metal separator may have the gasket line formed on the surface of the reaction surface of the metal separator body and the gasket line not formed on the surface of the cooling surface, or the gasket line formed on the surfaces of the reaction surface and the cooling surface of the metal separator body, and the air electrode metal separator may have the gasket line formed on the surfaces of the reaction surface and the cooling surface of the metal separator body, or the gasket line may be formed on the surface of the reaction surface of the metal separator body and the gasket line not formed on the surface of the cooling surface.

[0021] In addition, the fuel cell stack of the present application includes the fuel cell cells as unit cells.

[0022] The present application relates to a metal separator, a fuel cell cell including the metal separator, and a fuel cell stack including the fuel cell cell. The metal separator of the present application prevents deformation of the manifold inlet / outlet holes, while ensuring airtightness and evenly distributing the flow rate of the injected and discharged reaction gas.

[0023] FIG. 1 is a top view illustrating a reaction surface of a hydrogen electrode metal separator according to one embodiment of the present application.

[0024] Fig. 2 is a top view illustrating a cooling surface of a hydrogen electrode metal separator according to one embodiment of the present application.

[0025] FIG. 3 is a top view illustrating a reaction surface of an air electrode metal separator according to one embodiment of the present application.

[0026] Fig. 4 is a top view illustrating a cooling surface of an air electrode metal separator according to one embodiment of the present application.

[0027] FIG. 5 is a top view showing an enlarged portion of a portion of a support gasket line of a metal separator according to one embodiment of the present application.

[0028] FIG. 6 is a side view illustrating an example of a fuel cell according to one embodiment of the present application.

[0029] FIG. 7 is a top view illustrating a fuel cell before a metal separator is laminated according to one embodiment of the present application.

[0030] Hereinafter, the metal separator of the present application will be described with reference to the attached drawings. The attached drawings are exemplary, and the metal separator of the present application is not limited to the attached drawings.

[0031] FIG. 1 is a top view exemplarily showing the reaction surface of a cathode metal separator according to an embodiment of the present application. FIG. 2 is a top view exemplarily showing the cooling surface of a cathode metal separator according to an embodiment of the present application. FIG. 3 is a top view exemplarily showing the reaction surface of an air cathode metal separator according to an embodiment of the present application. FIG. 4 is a top view exemplarily showing the cooling surface of an air cathode metal separator according to an embodiment of the present application. As shown in FIGS. 1 to 4, the metal separator of the present application includes a metal separator body (11) and a gasket line (12). According to the metal separator of the present application, deformation of the manifold inlet / outlet hole (114) can be prevented, airtightness can be secured, and the flow rate of the injected and discharged reaction gas can be uniformly distributed.

[0032] The above metal separator body (11) is a main component used in a metal separator for a fuel cell, and includes a reaction surface (111), a cooling surface (112), a manifold part (113), and a manifold inlet / outlet hole (114).

[0033] In one example, the type of the metal separator body (11) is not particularly limited, and any metal base material used in a metal separator for a fuel cell can be used without limitation. For example, the metal separator body (11) may be a base material made of stainless steel, titanium, aluminum, magnesium, or an alloy thereof. Specifically, the metal base material may be a STS 300 series such as STS 316L, a base material made of stainless steel, or a STS 400 series such as STS 443CT or STS 470FC, or a Grade 1 base material made of titanium. By using the above-described metal base material as the metal separator body (11), the metal separator may have excellent electrical conductivity and corrosion resistance.

[0034] The above reaction surface (111) is a part where an electrochemical reaction occurs by the reaction gas supplied and discharged through the metal separator, and includes a reaction path (1111) provided on one side of the metal separator body (11) and positioned centrally with respect to the flow direction of the reaction gas. In the present specification, the “flow direction of the reaction gas” refers to the direction in which the reaction gas flows along the reaction path (1111), and may be, for example, the same as the longitudinal direction of the metal separator body (11).

[0035] The above reaction path (1111) includes a plurality of path sections formed by extending along the flow direction of the reaction gas.

[0036] In one example, the height of the reaction channel (1111) may be 0.20 mm to 0.60 mm, specifically, 0.30 mm to 0.55 mm or 0.40 mm to 0.50 mm. In this case, the height of the reaction channel (1111) refers to the length measured along the thickness direction of the inner side of the reaction channel (1111). By having the height described above, the reaction channel (1111) may have excellent supply properties of the reaction gas.

[0037] Additionally, the pitch between the plurality of flow sections may be 0.5 mm to 2.0 mm, specifically, 0.8 mm to 1.6 mm or 1.0 mm to 1.2 mm. By satisfying the above-described range of pitch between the plurality of flow sections, the performance of the fuel cell can be maximized.

[0038] The above cooling surface (112) is a portion through which cooling water flows to remove heat generated by the electrochemical reaction of the reaction gas at the reaction surface (111), and is located opposite the reaction surface (111) provided in the metal separator body (11) and includes a cooling channel (1121) located at the center with respect to the flow direction of the cooling water. In the present specification, the “flow direction of the cooling water” refers to the direction in which the cooling water flows along the cooling channel (1121), and may be, for example, the same as the longitudinal direction of the metal separator body (11).

[0039] The above cooling channel (1121) includes a plurality of channel sections formed by extending along the flow direction of the cooling water.

[0040] In one example, the height of the cooling channel (1121) may be 0.20 mm to 0.60 mm, specifically, 0.30 mm to 0.55 mm or 0.40 mm to 0.50 mm. In this case, the height of the cooling channel (1121) refers to the length measured along the thickness direction of the inner side of the cooling channel (1121). Since the cooling channel (1121) has the height described above, the supply of cooling water may be excellent.

[0041] Additionally, the pitch between the plurality of flow sections may be 0.5 mm to 2.0 mm, specifically, 0.8 mm to 1.6 mm or 1.0 mm to 1.2 mm. By satisfying the above-described range of pitch between the plurality of flow sections, the performance of the fuel cell can be maximized.

[0042] The above manifold part (113) is a part that supplies and discharges reaction gas and cooling water for the electrochemical reaction of the metal separator, and includes at least one pair of first reaction gas manifolds (1131), at least one pair of cooling water manifolds (1132), and at least one pair of second reaction gas manifolds (1133) that are formed by penetrating the reaction surface (111) and the cooling surface (112) on both sides of each of the reaction path (1111) and the cooling path (1121). In this specification, the term “a pair” means that two parts formed on both sides of each of the reaction path and the cooling path form a pair. In addition, the term “at least one pair” in this specification means that there is at least one part that performs the same function and forms a pair, and the upper limit thereof is not particularly limited unless specifically stated.

[0043] Specifically, one or more pairs of first reaction gas manifolds (1131) and one or more pairs of second reaction gas manifolds (1133) may be formed with hydrogen and air inlets and outlets for supplying and discharging reaction gases, respectively, and one or more pairs of cooling water manifolds (1132) may be formed with cooling water inlets and outlets for controlling the operating temperature. In one embodiment, the reaction surface (111) may be formed at one end with respect to the longitudinal direction of the metal separator body (11), and one or more first reaction gas manifolds (1131), one or more cooling water manifolds (1132), and one or more second reaction gas manifolds (1133) may be arranged along a width direction perpendicular to the longitudinal direction of the metal separator body (11), specifically, one or more first reaction gas outlets, one or more cooling water outlets, and one or more second reaction gas inlets may be arranged. In addition, on the reaction surface (111), one or more second reaction gas manifolds (1133), one or more cooling water manifolds (1132), and one or more first reaction gas manifolds (1131) may be formed at the other end with respect to the longitudinal direction of the metal separator body (11), and may be arranged along the width direction perpendicular to the longitudinal direction of the metal separator body (11). Specifically, one or more second reaction gas outlets, one or more cooling water inlets, and one or more first reaction gas inlets may be arranged. That is, one or more pairs of the first reaction gas manifolds (1131) and one or more pairs of the second reaction gas manifolds (1133) may be arranged such that each pair is staggered. At this time, one or more pairs of first reaction gas manifolds (1131) and one or more pairs of second reaction gas manifolds (1133) may be arranged on the cooling surface (112) so as to face the reaction surface (111). In this specification, the term “longitudinal direction of the metal separator body” means the direction from one end to the other end of the metal separator body (11).In addition, in this specification, the term "width direction of the metal separator body" means a direction perpendicular to the longitudinal direction. At this time, the first reaction gas may be hydrogen or air, and the second reaction gas may be hydrogen or air different from the first reaction gas. In one embodiment, when the metal separator is a hydrogen electrode metal separator, the first reaction gas may be air, and the second reaction gas may be hydrogen. In addition, in another embodiment, when the metal separator is an air electrode metal separator, the first reaction gas may be hydrogen, and the second reaction gas may be air.

[0044] The above manifold inlet / outlet holes (114) are holes that allow the first reaction gas or the second reaction gas supplied through the manifold part (113) to flow into the reaction path (1111), specifically, the diffusion path (115) described later, or allow the first reaction gas or the second reaction gas that has passed through the reaction path (1111), specifically, the diffusion path (115) described later, to flow into the manifold part (113), and are formed in plurality by penetrating the reaction surface (111) and the cooling surface (112) between one or more pairs of second reaction gas manifolds (1133) and each of the reaction paths (1111) and the cooling path (1121). In the present specification, the term “plurality” means two or more, and the upper limit thereof is not particularly limited unless otherwise specified.

[0045] In one example, the metal separator body (11) may further include a diffusion path (115) that is connected to each of the reaction path (1111) and the cooling path (1121) and extends to a plurality of manifold inlet / outlet holes (114). The diffusion path (115) is a path that distributes a reaction gas, specifically a second reaction gas, introduced through a plurality of manifold inlet / outlet holes (114) to each of a plurality of path sections of the reaction path (1111), and then discharges the distributed reaction gas to the plurality of manifold inlet / outlet holes (114), and distributes the cooling water introduced through the cooling water manifold (1132) to each of a plurality of path sections of the cooling path (1121), and then discharges the distributed cooling water to the plurality of manifold inlet / outlet holes (114). That is, the diffusion path (115) may be provided between each of a plurality of manifold inlet / outlet holes (114) adjacent to each of one or more pairs of the second reaction gas manifolds (1133) on the reaction surface (111) and the reaction path (1111), thereby forming one or more pairs, and may also be provided between each of a plurality of manifold inlet / outlet holes (114) adjacent to each of one or more pairs of the second reaction gas manifolds (1133) on the cooling surface (112), thereby forming one or more pairs.

[0046] The above gasket line (12) is a packing formed to secure airtightness of the first reaction gas, second reaction gas, and cooling water flowing in the metal separator body (11) when stacking fuel cell cells using the metal separator, which will be described later, and is formed on the surface of at least one side of the metal separator body.

[0047] In one example, the gasket line (12) may be formed on the surface of the reaction surface (111) and the cooling surface (112) of the metal separator body (11), or may be formed on the surface of the reaction surface (111) of the metal separator body and not formed on the surface of the cooling surface (112). Specifically, when the metal separator is a hydrogen electrode metal separator described below, the gasket line (not shown) may be formed on the surface of the reaction surface (not shown) and not formed on the surface of the cooling surface (not shown), or may be formed on the surface of the reaction surface (111) and the surface of the cooling surface (112), as shown in FIGS. 1 and 2. In addition, when the metal separator is the cathode metal separator described later, the gasket line (not shown) may be formed on the surface of the reaction surface (not shown) and the cooling surface (not shown), or, as shown in FIGS. 3 and 4, may be formed on the surface of the reaction surface (111) and not formed on the surface of the cooling surface (112). More specifically, when the gasket line in the hydrogen electrode metal separator is formed on the surface of the reaction surface and not formed on the surface of the cooling surface, the gasket line in the cathode metal separator may be formed on the surfaces of the reaction surface and the cooling surface. In addition, when the gasket line (12) in the hydrogen electrode metal separator is formed on the surface of the reaction surface (111) and the surface of the cooling surface (112), the gasket line (12) in the cathode metal separator may be formed on the surface of the reaction surface (111) and not formed on the surface of the cooling surface (112).

[0048] In one example, the gasket line (12) may include fluorocarbon rubber (FKM), ethylene propylene diene terpolymer (EPDM), or vinyl methyl silicone rubber (LSR). Specifically, when the gasket line (12) includes fluorocarbon rubber (FKM), it has superior material properties such as oxidation resistance and flame retardancy compared to other rubber materials due to its high fluorination degree, has superior stability due to the high bonding strength of carbon and fluorine, and has a low burr generation rate during operation, so that productivity and workability may be excellent. When the gasket line (12) includes ethylene propylene diene terpolymer (EPDM), it may be inexpensive and have excellent cold resistance, water resistance, freeze resistance, and resistance to alcohols and ketones. In addition, the gasket line (12) has a low burr generation rate during operation when it includes vinyl methyl silicone rubber (LSR), so it has excellent material utilization rate, productivity, and workability, and can be inexpensive and has excellent low-temperature resistance.

[0049] The above gasket line (12) includes a manifold gasket line (121), a euro gasket line (122), and a support gasket line (123).

[0050] The above manifold gasket line (121) surrounds the entire perimeter of each of at least one pair of first reaction gas manifolds (1131), at least one pair of cooling water manifolds (1132), and at least one pair of second reaction gas manifolds (1133), as shown in FIGS. 1 and 3, or surrounds the entire perimeter of each of at least one pair of first reaction gas manifolds (1131) and at least one pair of second reaction gas manifolds (1133), as shown in FIG. 2. In the present specification, the phrase "the gasket line surrounds the entire perimeter" means that the entire perimeter is surrounded by one gasket line.

[0051] The above-described euro gasket line (122) is connected to the manifold gasket line (121) and surrounds the reaction channel (1111) and a plurality of manifold inlet / outlet holes (114), or surrounds the cooling channel (1121) and one or more pairs of cooling water manifolds (1132). At this time, the euro gasket line (122) surrounding the reaction channel (1111) and a plurality of manifold inlet / outlet holes (114) may be connected to and integrated with the manifold gasket line (121) located on both sides of the reaction channel (1111), and the euro gasket line (122) surrounding the cooling channel (1121) and a plurality of cooling water manifolds (1132) may be connected to and integrated with the manifold gasket line (121) located on both sides of the cooling channel (1121).

[0052] The above-mentioned support gasket line (123) extends from the manifold gasket line (121) located at the inner edge of each of one or more second reaction gas manifolds (1133) toward the reaction path (1111) or each of one or more second reaction gas manifolds (1133), and is formed in multiple numbers between the multiple manifold inlet / outlet holes (114). In this specification, the term "inner edge" means the edge that is located closest to the reaction path or the cooling path among all edges. In addition, the term "extension" in this specification means that it is formed toward a specific direction. The metal separator includes the above-mentioned support gasket line (123), thereby preventing deformation of the manifold inlet / outlet hole (114), securing airtightness, and evenly distributing the flow rate of the injected and discharged reaction gas. FIG. 5 is an exemplary drawing showing a partial area enlarged to explain the support gasket line of the metal separator according to one embodiment of the present application. As shown in Fig. 5, the support gasket line (123) satisfies the following general formula 1.

[0053] [General Formula 1]

[0054] (B-(B×0.5))2 ≤ D ≤ (B+(B×0.5))2

[0055] In the above general formula 1, D is the length of the gasket line, and B is the width of the manifold gasket line.

[0056] That is, the length (D) of the support gasket line is 1 to 3 times the width (B) of the manifold gasket line. Specifically, the length (D) of the support gasket line may be 1.5 to 2.5 times the width (B) of the manifold gasket line. When the length (D) of the support gasket line satisfies the above-described range, deformation of the manifold inlet / outlet hole (114) is prevented, while airtightness is secured, and the flow rate of the injected and discharged reaction gas can be uniformly distributed. In contrast, when the length (D) of the support gasket line is less than the lower limit and greater than the upper limit of the above-described range, deformation may occur in the manifold inlet / outlet hole (114), or a gap may be formed in the middle of the sub-gasket line, causing reaction gas and cooling water to flow into the gap, making it difficult to secure airtightness.

[0057] For example, the width (B) of the manifold gasket line may be 2 mm to 5 mm, and specifically, the width of the manifold gasket line may be 3 mm to 4 mm. When the width (B) of the manifold gasket line satisfies the above-described range, deformation of the manifold inlet / outlet hole (114) can be prevented, while airtightness can be secured, and the flow rate of the injected and discharged reaction gas can be uniformly distributed. In contrast, when the width (B) of the manifold gasket line is less than the lower limit and greater than the upper limit of the above-described range, deformation may occur in the manifold inlet / outlet hole (114), or a gap may be formed in the middle of the sub-gasket line, causing reaction gas and cooling water to flow into the gap, making it difficult to secure airtightness.

[0058] In another example, the gasket line (123) can satisfy the following general formula 2.

[0059] [General Formula 2]

[0060] (B-(B×0.2))2 ≤ C ≤ (B+(B×0.2))2

[0061] In the above general formula 2, C is the pitch of the support gasket line, and B is the width of the manifold gasket line.

[0062] That is, the pitch (C) of the support gasket line is 1.6 to 2.4 times the width (B) of the manifold gasket line. Specifically, the pitch (C) of the support gasket line may be 1.8 to 2.2 times the width (B) of the manifold gasket line. When the pitch (C) of the support gasket line satisfies the above-described range, deformation of the manifold inlet / outlet hole (114) is prevented, while airtightness is secured, and the flow rate of the injected and discharged reaction gas can be uniformly distributed. In contrast, when the pitch (C) of the support gasket line is less than the lower limit and greater than the upper limit of the above-described range, deformation may occur in the manifold inlet / outlet hole (114), or a gap may be formed in the middle of the sub-gasket line, causing reaction gas and cooling water to flow into the gap, making it difficult to secure airtightness.

[0063] In another example, the support gasket line (123) can satisfy the following general formula 3.

[0064] [General Formula 3]

[0065] B-(B×0.2) ≤ A ≤ B+(B×0.2)

[0066] In the above general formula 3, A is the width of the support gasket line, and B is the width of the manifold gasket line.

[0067] That is, the width (A) of the support gasket line is 0.8 to 1.2 times the width (B) of the manifold gasket line. Specifically, the width (A) of the support gasket line may be 0.9 to 1.1 times the width (B) of the manifold gasket line. When the width (A) of the support gasket line satisfies the above-described range, deformation of the manifold inlet / outlet hole (114) is prevented, while airtightness is secured, and the flow rate of the injected and discharged reaction gas can be uniformly distributed. In contrast, when the width (A) of the support gasket line is less than the lower limit and greater than the upper limit of the above-described range, deformation may occur in the manifold inlet / outlet hole (114), or a gap may be formed in the middle of the sub-gasket line, causing reaction gas and cooling water to flow into the gap, making it difficult to secure airtightness.

[0068] In another example, the thickness of the support gasket line (123) is not particularly limited, as it can be controlled according to the material properties of the gas diffusion layer described later.

[0069] In addition, a plurality of support gasket lines (123) may be further formed by extending from the manifold gasket line (121) located at the inner edge of each of one or more pairs of first reaction gas manifolds (1131) toward the reaction path (1111) or one or more pairs of first reaction gas manifolds (1131). By further forming a plurality of support gasket lines (123) at the aforementioned positions, deformation of the manifold inlet / outlet holes (114) can be prevented when stacking fuel cell cells as described later.

[0070] In one example, the metal separator may further include a metal coating layer (not shown) or a surface modification layer (not shown) formed on the surface of the metal separator body (11), or the surface of the metal separator body (11) on which the gasket line (12) is formed. Specifically, when the metal coating layer or the surface modification layer is formed before forming the gasket line (12) on the metal separator body (11), the manufactured metal separator may have the metal coating layer or the surface modification layer formed only on the surface of the metal separator body (11). In contrast, when the metal coating layer or the surface modification layer is formed after forming the gasket line (12) on the metal separator body (11), the manufactured metal separator may have the metal coating layer or the surface modification layer formed on the surface of the metal separator body (11) on which the gasket line (12) is formed. The above metal separator can secure excellent corrosion resistance and electrical conductivity by further including the metal coating layer or the surface modification layer formed on the surface described above.

[0071] At this time, the metal coating layer may include one or more precious metal particles and a passive film formed between one or more precious metal particles.

[0072] For example, the above-mentioned precious metal particles (1231) may be at least one selected from gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), and iridium (Ir). By including the above-mentioned precious metal particles, the metal coating layer can secure excellent corrosion resistance and electrical conductivity.

[0073] The above-described passive film can be formed on the surface of the metal separator body (11) where the precious metal particles are not in contact with one or more of the precious metal particles, or on the surface of the metal separator body (11) on which the gasket line (12) is formed. By forming the passive film at the above-described location, oxygen can be prevented from penetrating into the interior of the metal separator body (11) on which the passive film is formed, thereby preventing rust from occurring.

[0074] In one example, the thickness of the passive film may be smaller than the length in the thickness direction of the precious metal particles. Since the thickness of the passive film is smaller than the length in the thickness direction of the precious metal particles, excellent corrosion resistance and electrical conductivity can be secured.

[0075] In addition, when the metal separator body (11) is made of stainless steel containing chromium, when the surface of the metal separator body (11) is exposed to the outside, a very thin Cr2O3 passive film having a thickness of 1 nm to 5 nm can be naturally formed on the surface, and when the passive film is modified, a surface modification layer can be formed. At this time, since the physical properties of each component included in the metal separator body (11) have physical properties known in the art, they will be omitted.

[0076] The present application also relates to a fuel cell. The fuel cell relates to a fuel cell including the aforementioned metal separator. Since the specific details of the metal separator described below are equally applicable to the description of the metal separator, they will be omitted.

[0077] Fig. 6 is a side view illustrating a fuel cell according to an embodiment of the present application. In addition, Fig. 7 is a top view illustrating a fuel cell before metal separators are laminated according to an embodiment of the present application. As illustrated in Fig. 6, the fuel cell includes a membrane electrode assembly (2) and a pair of the aforementioned metal separators (1). By including the pair of the aforementioned metal separators, the fuel cell can prevent deformation of the manifold inlet / outlet holes during lamination while ensuring airtightness.

[0078] The above membrane electrode assembly (2) is a film-shaped assembly that converts a chemical reaction of a reaction gas supplied from the metal separator into electrical energy, and is surrounded by a sub-gasket line (21) on the outside. In the present specification, being surrounded by the outside means that an outer edge positioned in a direction perpendicular to the stacking direction is surrounded. At this time, as the membrane electrode assembly (2), any type known in the art can be used without special limitation as long as the outside is surrounded by a sub-gasket line (21).

[0079] A pair of metal separators (1) are stacked so that the reaction surfaces (111) face the lower and upper portions of the membrane electrode assembly (2) such that the sub gasket line (21) contacts the support gasket line (123). At this time, when the support gasket line (123) formed on the reaction surface (111) of each of the pair of metal separators (1) contacts the western gasket line (21), the support gasket lines (123) formed on the reaction surfaces (111) of each of the pair of metal separators (1) can be arranged to face each other.

[0080] In addition, the metal separator (1) disposed at the bottom of the membrane electrode assembly (2) of the fuel cell may be a hydrogen electrode metal separator, and the metal separator (1) disposed at the top of the membrane electrode assembly (2) may be an air electrode metal separator.

[0081] At this time, the hydrogen electrode metal separator may have the gasket line (12) formed on the surface of the reaction surface (111) of the metal separator body (11), and the gasket line (12) may not be formed on the surface of the cooling surface (112), or the gasket line (12) may be formed on the surfaces of the reaction surface (111) and the cooling surface (112) of the metal separator body (11).

[0082] In addition, the air electrode metal separator may have the gasket line (12) formed on the surface of the reaction surface (111) and the cooling surface (112) of the metal separator body (11), or the gasket line (12) may be formed on the surface of the reaction surface (111) of the metal separator body (11), and the gasket line (12) may not be formed on the surface of the cooling surface (112).

[0083] That is, even if the gasket line (12) is formed on the surface of the cooling surface (112) included in the hydrogen electrode metal separator and the gasket line (12) is not formed on the surface of the cooling surface (112) included in the air electrode metal separator, or the gasket line (12) is formed on the surface of the cooling surface (112) included in the air electrode metal separator and the gasket line (12) is not formed on the surface of the cooling surface (112) included in the hydrogen electrode metal separator, it is possible to secure the airtightness of the cooling surface (112) when stacking fuel cell cells into unit cells.

[0084] In one example, as shown in FIGS. 6 and 7, the fuel cell may further include a pair of gas diffusion layers (3) each provided between a pair of metal separators (1) and a membrane electrode assembly (2). At this time, any type known in the art may be used as the gas diffusion layers (3) without limitation, and is not particularly limited.

[0085] The present application also relates to a fuel cell stack. The fuel cell stack comprises the aforementioned fuel cell as a unit cell. Since the specific details of the fuel cell described below are equally applicable to the fuel cell described above, they will be omitted.

[0086] As described above, the fuel cell stack includes fuel cell cells as unit cells. By including the fuel cell cells as unit cells, the fuel cell stack can prevent deformation of the separator during stacking and ensure airtightness.

[0087] <Explanation of symbols>

[0088] 1: Metal separator

[0089] 11: Metal separator body

[0090] 111: Reaction surface

[0091] 1111: Reaction flow

[0092] 112: Cold noodles

[0093] 1121: Cooling oil

[0094] 113: Manifold section

[0095] 1131: First reactor gas manifold

[0096] 1132: Coolant Manifold

[0097] 1133: Second reactor gas manifold

[0098] 114: Manifold inlet and outlet holes

[0099] 115: Diffusion Euro

[0100] 12: Gasket line

[0101] 121: Manifold gasket line

[0102] 122: Euro gasket line

[0103] 123: Support gasket line

[0104] 2: Membrane electrode assembly

[0105] 21: Sub gasket line

[0106] 3: Gas diffusion layer

[0107] A: Width of the support gasket line

[0108] B: Width of manifold gasket line

[0109] C: Pitch of support gasket line

[0110] D: Length of support gasket line

Claims

1. A metal separator including a metal separator body and a gasket line formed on the surface of at least one surface of the metal separator body, The above metal separator body has a reaction surface including a reaction path, A cooling surface located opposite the above reaction surface and including a cooling channel, A manifold section including at least one pair of first reaction gas manifolds, at least one pair of cooling water manifolds, and at least one pair of second reaction gas manifolds formed by penetrating the reaction surface and the cooling surface on both sides of each of the reaction path and the cooling path, and It comprises one or more pairs of second reaction gas manifolds, and a plurality of manifold inlet and outlet holes formed between the reaction path and the cooling path, respectively, penetrating the reaction surface and the cooling surface, The gasket line surrounds the entire perimeter of each of at least one pair of first reactor gas manifolds, at least one pair of coolant manifolds, and at least one pair of second reactor gas manifolds, or a manifold gasket line surrounds the entire perimeter of each of at least one pair of first reactor gas manifolds and at least one pair of second reactor gas manifolds. A flow path gasket line connected to the above manifold gasket line and surrounding the reaction flow path and a plurality of manifold inlet and outlet holes, or surrounding the cooling flow path and one or more pairs of cooling water manifolds, and A plurality of support gasket lines formed between a plurality of manifold inlet and outlet holes extending from the manifold gasket lines positioned on the inner edge of each of the pair or more second reaction gas manifolds toward the reaction path, or each of the pair or more second reaction gas manifolds, The above support gasket line is a metal separator satisfying the following general formula 1: [General Formula 1] (B-(B×0.5))2 ≤ D ≤ (B+(B×0.5))2 In the above general formula 1, D is the length of the gasket line, and B is the width of the manifold gasket line.

2. In paragraph 1, The above manifold gasket line is a metal separator having a width of 2 mm to 5 mm.

3. In paragraph 1, The above gasket line is a metal separator comprising fluorocarbon rubber (FKM), ethylene propylene diene terpolymer (EPDM) or vinyl methyl silicone rubber (LSR).

4. In paragraph 1, A metal separator plate in which a plurality of support gasket lines are formed by extending from the manifold gasket lines located on the inner edge of each of the one or more pairs of first reaction gas manifolds toward the reaction path, or each of the one or more pairs of first reaction gas manifolds.

5. In paragraph 1, The above gasket line is formed on the surface of the reaction surface and the cooling surface of the metal separator body, or A metal separator formed on the surface of the reaction surface of the metal separator body and not formed on the surface of the cooling surface.

6. In paragraph 1, The above metal separator body is a metal separator made of a base material of stainless steel, titanium, aluminum, magnesium or an alloy of these.

7. In paragraph 1, A metal separator body further including a diffusion path connected to each of the reaction path and the cooling path and extending toward a plurality of manifold inlet and outlet holes.

8. In paragraph 7, A metal separator further comprising a metal coating layer formed on the surface of the metal separator body, or the surface of the metal separator body having the gasket line formed on the surface; or a surface modification layer.

9. A membrane electrode assembly surrounded by a sub-gasket line; and A fuel cell cell comprising a pair of metal separators according to claim 1, each of which is laminated with the reaction surface facing the lower and upper portions of the membrane electrode assembly, such that the sub-gasket line is in contact with the support gasket line.

10. In paragraph 9, The metal separator placed at the bottom of the above membrane electrode assembly is a hydrogen electrode metal separator, A fuel cell in which the metal separator plate disposed on the upper portion of the above membrane electrode assembly is an air electrode metal separator plate.

11. In paragraph 10, The above hydrogen electrode metal separator has the gasket line formed on the surface of the reaction surface of the metal separator body, and the gasket line is not formed on the surface of the cooling surface, or the gasket line is formed on the surfaces of the reaction surface and the cooling surface of the metal separator body. The above air electrode metal separator is a fuel cell in which the gasket line is formed on the surface of the reaction surface and the cooling surface of the metal separator body, or the gasket line is formed on the surface of the reaction surface of the metal separator body, and the gasket line is not formed on the surface of the cooling surface.

12. A fuel cell stack comprising a fuel cell cell according to Article 9 as a unit cell.

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