Metal Separator

Abstract

This application relates to a metal separator, a fuel cell cell including the metal separator, and a fuel cell stack including the fuel cell. The metal separator of this application prevents deformation of the manifold inlet / outlet holes, ensures airtightness, and allows for uniform distribution of the flow rate of the reaction gas to be injected and discharged.

Description

Technical Field

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

Background Art

[0002] In recent years, in response to global warming, the powertrain has been changing from an internal combustion engine (ICE) to an electric vehicle (EV) or a hydrogen fuel cell vehicle (FCEV). The fuel cell used in a hydrogen fuel cell vehicle (FCEV) not only supplies industrial, household, and driving power for vehicles, but is also used for power supply of small electronic products such as portable devices, and is a highly efficient clean energy source in terms of both energy conservation and environmental protection, and its usage area is gradually expanding.

[0003] A hydrogen fuel cell is a kind of power generation device that electrochemically reacts the chemical energy of fuel in a stack and converts it into electrical energy, and generates electricity using the energy generated during the bonding reaction of hydrogen and oxygen. Specifically, a hydrogen fuel cell can use hydrogen gas as fuel, and the oxidation reaction of hydrogen gas proceeds to generate hydrogen ions (Protons) and electrons (Electrons). At this time, the generated hydrogen ions and electrons undergo an electrochemical reaction with oxygen in the air to generate water and generate electrical energy from the flow of electrons.

[0004] Such a hydrogen fuel cell is composed of a metal separator plate (Metal Separator), a gas diffusion layer (GDL), and a membrane electrode assembly (Membrane Electrode Assembly). In particular, among such a configuration, the metal separator plate is a core component that constitutes a fuel cell stack together with the gas diffusion layer and the membrane electrode assembly, separates hydrogen, oxygen, and cooling water respectively, uniformly distributes and supplies them to the entire surface of the membrane electrode assembly, and collects (Anode) and transmits (Cathode) the current generated by the electrochemical reaction.

[0005] Metal separators have gasket lines formed on their surface to maintain airtightness and prevent hydrogen, oxygen, and cooling water flowing through the channels from leaking into other areas. However, because metal separators are extremely thin plates, if the gasket lines are not optimized, the pressure applied when stacking numerous cells can cause deformation of the manifold inlet / outlet holes of the metal separator, or the sub-gasket lines may not be pressed tightly enough, resulting in gaps in the sub-gasket lines. When deformation occurs in the manifold inlet / outlet holes or gaps occur in the sub-gasket lines, it becomes difficult to ensure airtightness. Therefore, to solve these problems, there is a need for a metal separator with a gasket shape that can prevent deformation of the manifold inlet / outlet holes while ensuring airtightness. [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of this application is to provide a metal separation plate that prevents deformation of the manifold inlet / outlet holes, ensures airtightness, and can uniformly distribute the flow rate of the reaction gas being injected and discharged. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a metal separation plate comprising a metal separation plate body and a gasket line formed on the surface of one or more surfaces of the metal separation plate body, wherein the metal separation plate body comprises a reaction surface including a reaction channel, a cooling surface located on the opposite side of the reaction surface and including a cooling channel, a manifold section comprising one or more first reaction gas manifolds, one or more cooling water manifolds, and one or more second reaction gas manifolds formed on both sides of the reaction channel and the cooling channel, penetrating the reaction surface and the cooling surface, and one or more second reaction gas manifolds, and a plurality of manifold inlet / outlet holes formed between the reaction channel and the cooling channel, penetrating the reaction surface and the cooling surface, and the gasket line comprises one or more first reaction gas manifolds, one or more cooling water manifolds The system includes manifold gasket lines that surround the entire edges of each of the nifold and one or more pairs of second reaction gas manifolds, or that surround the entire edges of each of the one or more pairs of first reaction gas manifolds and one or more pairs of second reaction gas manifolds, flow path gasket lines connected to the manifold gasket lines that surround the reaction channel and a plurality of manifold inlet / outlet holes, or that surround the cooling channel and one or more pairs of cooling water manifolds, and a plurality of support gasket lines that extend from the manifold gasket lines located on the inner edges of each of the one or more pairs of second reaction gas manifolds toward the reaction channel or each of the one or more pairs of second reaction gas manifolds and are formed between a plurality of manifold inlet / outlet holes, wherein the support gasket lines satisfy the following general formula 1.

[0008] [General formula 1]

[0009] B-(B×0.2) ≦ A ≦ B+(B×0.2)

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

[0011] The aforementioned support gasket line satisfies the following general formula 2.

[0012] [General formula 2]

[0013] (B-(B×0.2))2 ≦ C ≦ (B+(B×0.2))2

[0014] 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.

[0015] Furthermore, the manifold gasket line may have a width of 2 mm to 5 mm.

[0016] Furthermore, the gasket line may include fluorocarbon rubber (FKM), ethylene propylene diene terpolymer (EPDM), or vinyl methyl silicone rubber (LSR).

[0017] Furthermore, multiple support gasket lines may be formed, extending from the manifold gasket lines located on the inner edges of each of the pair or more first reaction gas manifolds toward the reaction flow path or toward each of the pair or more first reaction gas manifolds.

[0018] Furthermore, the gasket line may be formed on the surface of the reaction surface and the cooling surface of the metal separation plate body, or it may be formed on the surface of the reaction surface and not on the surface of the cooling surface of the metal separation plate body.

[0019] Furthermore, the metal separation plate body may be made of stainless steel, titanium, aluminum, magnesium, or an alloy thereof.

[0020] Furthermore, the metal separation plate body may further include diffusion channels connected to each of the reaction channels and the cooling channels, and extending toward a plurality of manifold inlet and outlet holes.

[0021] Further, the metal separation plate may further include a metal coating layer formed on the surface of the metal separation plate body or on the surface of the metal separation plate body where the gasket line is formed; or a surface modification layer.

[0022] Furthermore, the fuel cell of the present application includes a membrane electrode assembly whose outer periphery is surrounded by a sub-gasket line; and a pair of the metal separation plates laminated such that the sub-gasket line contacts the support gasket line and reaction surfaces face the lower and upper portions of the membrane electrode assembly, respectively.

[0023] Also, the metal separation plate disposed below the membrane electrode assembly may be a hydrogen electrode metal separation plate, and the metal separation plate disposed above the membrane electrode assembly may be an air electrode metal separation plate.

[0024] Furthermore, in the hydrogen electrode metal separation plate, the gasket line is formed on the surface of the reaction surface of the metal separation plate 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 separation plate body. In the air electrode metal separation plate, the gasket line is formed on the surfaces of the reaction surface and the cooling surface of the metal separation plate body, or the gasket line may not be formed on the surface of the cooling surface even if the gasket line is formed on the surface of the reaction surface of the metal separation plate body.

[0025] Also, the fuel cell stack of the present application includes the fuel cell as a unit cell.

Advantages of the Invention

[0026] The present application relates to a metal separation plate, a fuel cell including the metal separation plate, and a fuel cell stack including the fuel cell. According to the metal separation plate of the present application, deformation of the manifold inlet / outlet holes can be prevented, airtightness can be ensured, and the flow rates of the reaction gases to be injected and discharged can be evenly distributed.

Brief Description of the Drawings

[0027] FIG. 1 is a top view exemplarily showing a reaction surface of a hydrogen electrode metal separator according to an embodiment of the present application.

[0028] FIG. 2 is a top view exemplarily showing a cooling surface of a hydrogen electrode metal separator according to an embodiment of the present application.

[0029] FIG. 3 is a top view exemplarily showing a reaction surface of an air electrode metal separator according to an embodiment of the present application.

[0030] FIG. 4 is a top view exemplarily showing a cooling surface of an air electrode metal separator according to an embodiment of the present application.

[0031] FIG. 5 is a top view exemplarily showing, for explaining a support gas gasket line of a metal separator according to an embodiment of the present application, a partially enlarged region.

[0032] FIG. 6 is a side view exemplarily showing a fuel cell according to an embodiment of the present application.

[0033] FIG. 7 is a top view exemplarily showing a fuel cell before metal separators are stacked according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, the metal separator of the present application will be described with reference to the accompanying drawings. The accompanying drawings are exemplary, and the metal separator of the present application is not limited by the accompanying drawings.

[0035] Figure 1 is an exemplary top view showing the reaction surface of a hydrogen electrode metal separation plate according to one embodiment of the present application. Figure 2 is an exemplary top view showing the cooling surface of a hydrogen electrode metal separation plate according to one embodiment of the present application. Figure 3 is an exemplary top view showing the reaction surface of an air electrode metal separation plate according to one embodiment of the present application. Figure 4 is an exemplary top view showing the cooling surface of an air electrode metal separation plate according to one embodiment of the present application. As shown in Figures 1 to 4, the metal separation plate of the present application includes a metal separation plate body 11 and a gasket line 12. The metal separation plate of the present application prevents deformation of the manifold inlet / outlet hole 114, ensures airtightness, and allows for uniform distribution of the flow rate of the reaction gas to be injected and discharged.

[0036] The metal separation plate body 11 is the main component used in a fuel cell metal separation plate and includes a reaction surface 111, a cooling surface 112, a manifold section 113, and a manifold inlet / outlet hole 114.

[0037] In one example, the type of metal separation plate body 11 is not particularly limited, and any metal base material used for fuel cell metal separation plates can be used without restriction. For example, the metal separation plate body 11 can be made of stainless steel, titanium, aluminum, magnesium, or alloys thereof. Specifically, the metal base material can be made of stainless steel such as STS 316L or other STS 300 series, or STS 443CT or STS 470FC or other STS 400 series, or a titanium base material such as Grade 1. By using the aforementioned metal base material in the metal separation plate body 11, the metal separation plate can have excellent electrical conductivity and corrosion resistance.

[0038] The reaction surface 111 is a portion where an electrochemical reaction occurs due to the reaction gases supplied and discharged via the metal separation plate, and includes a reaction channel 1111 located in the center with respect to the flow direction of the reaction gas, provided on one of the surfaces of the metal separation plate body 11. In this specification, "flow direction of the reaction gas" is the direction in which the reaction gas flows along the reaction channel 1111, and may be, for example, the same as the longitudinal direction of the metal separation plate body 11.

[0039] The reaction channel 1111 includes a plurality of channel sections that extend along the flow direction of the reaction gas.

[0040] 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 from the inside of the reaction channel 1111 along the thickness direction. The reaction channel 1111 has excellent reaction gas supply capabilities due to having the aforementioned height.

[0041] Furthermore, the pitch between the multiple flow channel sections may be between 0.5 mm and 2.0 mm, specifically between 0.8 mm and 1.6 mm, or between 1.0 mm and 1.2 mm. By ensuring that the pitch between the multiple flow channel sections satisfies the aforementioned range, the performance of the fuel cell can be maximized.

[0042] The cooling surface 112 is the portion through which cooling water flows to remove heat generated by the electrochemical reaction of the reaction gas on the reaction surface 111, and includes a cooling channel 1121 located on the opposite side of the reaction surface 111 and centrally located with respect to the direction of cooling water flow, provided on the metal separation plate body 11. In this specification, "direction of cooling water flow" is 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 separation plate body 11.

[0043] The cooling channel 1121 includes a plurality of channel sections that are formed extending along the direction of cooling water flow.

[0044] 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 from the inside of the reaction channel 1121 along the thickness direction. The cooling channel 1121 has excellent cooling water supply capabilities due to having the aforementioned height.

[0045] Furthermore, the pitch between the multiple flow channel sections may be between 0.5 mm and 2.0 mm, specifically between 0.8 mm and 1.6 mm, or between 1.0 mm and 1.2 mm. By ensuring that the pitch between the multiple flow channel sections satisfies the aforementioned range, the performance of the fuel cell can be maximized.

[0046] The manifold section 113 is a section for supplying and discharging reaction gas and cooling water for the electrochemical reaction of the metal separator plate, and includes one or more first reaction gas manifolds 1131, one or more cooling water manifolds 1132, and one or more second reaction gas manifolds 1133, which are formed on both sides of the reaction channel 1111 and the cooling channel 1121, penetrating the reaction surface 111 and the cooling surface 112, respectively. In this specification, the term "one pair" means two parts formed on both sides of the reaction channel and the cooling channel, forming a set. Also in this specification, the term "one or more pairs" means one or more parts that perform the same function and form a pair, and there is no upper limit unless otherwise specified.

[0047] Specifically, one or more first reaction gas manifolds 1131 and one or more second reaction gas manifolds 1133 are each formed with hydrogen and air inlets and outlets for supplying and discharging reaction gases, and one or more cooling water manifolds 1132 may be formed with cooling water inlets and outlets for adjusting the operating temperature. In one embodiment, 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 on the reaction surface 111, which is formed at one end of the metal separation plate body 11 in the longitudinal direction and along the width direction perpendicular to the longitudinal direction of the metal separation plate body 11, and 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. Furthermore, 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 arranged along the width direction perpendicular to the longitudinal direction of the metal separation plate body 11, formed at the other end of the metal separation plate body 11 with respect to its longitudinal direction. 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 first reaction gas manifolds 1131 and one or more pairs of second reaction gas manifolds 1133 may be arranged such that each pair or more is offset from the others. At this time, on the cooling surface 112, one or more pairs of first reaction gas manifolds 1131 and one or more pairs of second reaction gas manifolds 1133 may be arranged facing the reaction surface 111. In this specification, the term "longitudinal direction of the metal separation plate body" means the direction from one end to the other in the metal separation plate body 11. Also, in this specification, the term "width direction of the metal separation plate body" means the direction perpendicular to the longitudinal direction. In this case, the first reaction gas may be hydrogen or air, and the second reaction gas may be a different hydrogen or air from the first reaction gas. In one embodiment, if the metal separation plate is a hydrogen electrode metal separation plate, the first reaction gas may be air, and the second reaction gas may be hydrogen.In another embodiment, when the metal separation plate is an air electrode metal separation plate, the first reaction gas may be hydrogen and the second reaction gas may be air.

[0048] The manifold inlet / outlet holes 114 are holes that allow the first or second reaction gas supplied via the manifold section 113 to flow into the reaction channel 1111, specifically the diffusion channel 115 described later, or allow the first or second reaction gas via the reaction channel 1111, specifically the diffusion channel 115 described later, to flow into the manifold section 113. Multiple such holes are formed between one or more second reaction gas manifolds 1133 and the reaction channel 1111 and the cooling channel 1121, respectively, penetrating the reaction surface 111 and the cooling surface 112. In this specification, the term "multiple" means two or more, and there is no upper limit unless otherwise specified.

[0049] In one example, the metal separation plate body 11 may further include a diffusion channel 115 connected to each of the reaction channel 1111 and the cooling channel 1121, and extending to a plurality of manifold inlet / outlet holes 114. The diffusion channel 115 is a channel that distributes the reaction gas flowing in through the plurality of manifold inlet / outlet holes 114, specifically the second reaction gas, to each of the plurality of channel sections of the reaction channel 1111, and then discharges the distributed reaction gas to the plurality of manifold inlet / outlet holes 114. It also distributes the cooling water flowing in through the cooling water manifold 1132 to each of the plurality of channel sections of the cooling channel 1121, and then discharges the distributed cooling water to the plurality of manifold inlet / outlet holes 114. In other words, the diffusion channels 115 are provided on the reaction surface 111 between each of the plurality of manifold inlet / outlet holes 114 adjacent to each of the pair or more second reaction gas manifolds 1133 and the reaction channels 1111, and can form one or more pairs. Similarly, on the cooling surface 112, the diffusion channels 115 are provided between each of the plurality of manifold inlet / outlet holes 114 adjacent to each of the pair or more second reaction gas manifolds 1133 and the reaction channels 1111, and can form one or more pairs.

[0050] The gasket line 12 is a packing formed to ensure airtightness of the first reaction gas, second reaction gas, and cooling water flowing in the metal separation plate body 11 when stacking fuel cell cells as described later using the metal separation plate, and is formed on the surface of one or more surfaces of the metal separation plate body.

[0051] 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 separation plate body 11, or it may be formed on the surface of the reaction surface 111 of the metal separation plate body but not on the surface of the cooling surface 112. Specifically, if the metal separation plate is a hydrogen electrode metal separation plate as described later, the gasket line (not shown) may be formed on the surface of the reaction surface (not shown) but not on the surface of the cooling surface (not shown), or it may be formed on the surface of the reaction surface 111 and the surface of the cooling surface 112, as shown in Figures 1 and 2. Also, if the metal separation plate is an air electrode metal separation plate as 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 it may be formed on the surface of the reaction surface 111 and not on the surface of the cooling surface 112, as shown in Figures 3 and 4. More specifically, in the hydrogen electrode metal separation plate, if the gasket line is formed on the surface of the reaction surface and not on the surface of the cooling surface, then in the air electrode metal separation plate, the gasket line may be formed on the surfaces of both the reaction surface and the cooling surface. Also, in the hydrogen electrode metal separation plate, if the gasket line 12 is formed on the surface of the reaction surface 111 and the surface of the cooling surface 112, then in the air electrode metal separation plate, the gasket line 12 may be formed on the surface of the reaction surface 111 and not on the surface of the cooling surface 112.

[0052] 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), its high degree of fluorination provides superior material properties such as oxidation resistance and flame retardancy compared to other rubber materials. Its high bond strength between carbon and fluorine provides excellent stability, and the low rate of burr formation during operation results in superior productivity and workability. When the gasket line 12 includes ethylene propylene diene terpolymer (EPDM), it is inexpensive and offers excellent cold resistance, water resistance, antifreeze resistance, and resistance to alcohols and ketones. Furthermore, when the gasket line 12 includes vinyl methyl silicone rubber (LSR), the low rate of burr formation during operation results in superior material utilization, productivity, and workability, as well as excellent low-temperature performance and potential low cost.

[0053] The gasket line 12 includes a manifold gasket line 121, a flow path gasket line 122, and a support gasket line 123.

[0054] As shown in Figures 1 and 3, the manifold gasket line 121 surrounds the entire edge of one or more first reaction gas manifolds 1131, one or more cooling water manifolds 1132, and one or more second reaction gas manifolds 1133, or as shown in Figure 2, surrounds the entire edge of one or more first reaction gas manifolds 1131 and one or more second reaction gas manifolds 1133, respectively. In this specification, "surrounding the entire edge of a gasket line" means that the entire edge is surrounded by a single gasket line.

[0055] The flow channel 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 cooling water manifolds 1132. In this case, the flow channel gasket line 122 surrounding the reaction channel 1111 and the plurality of manifold inlet / outlet holes 114 may be connected to and integrated with the manifold gasket lines 121 located on both sides of the reaction channel 1111, and the flow channel 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 lines 121 located on both sides of the cooling channel 1121.

[0056] The support gasket lines 123 extend from the manifold gasket lines 121 located on the inner edge of each of the pair or more second reaction gas manifolds 1133 toward the reaction channel 1111 or toward each of the pair or more second reaction gas manifolds 1133, and are formed in multiple locations between the multiple manifold inlet / outlet holes 114. In this specification, the term "inner edge" means the edge of the entire edge that is closest to the reaction channel or cooling channel. Also, in this specification, the term "extends" means formed toward a specific direction. By including the support gasket lines 123, the metal separator plate prevents deformation of the manifold inlet / outlet holes 114, ensures airtightness, and allows for uniform distribution of the flow rate of the reaction gas to be injected and discharged. Figure 5 is a top view illustrating an enlarged portion of a part of the support gasket line of a metal separator plate according to one embodiment of this application. As shown in Figure 5, the support gasket line 123 satisfies the following general formula 1.

[0057] [General formula 1]

[0058] B-(B×0.2) ≦ A ≦ B+(B×0.2)

[0059] In the above general formula 1, A is the width of the support gasket line, and B is the width of the manifold gasket line.

[0060] In other words, 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. By the width A of the support gasket line satisfying the above range, deformation of the manifold inlet / outlet hole 114 is prevented, airtightness is ensured, and the flow rate of the injected and discharged reaction gas can be distributed uniformly. On the other hand, if the width A of the support gasket line is less than the lower limit or more than the upper limit of the above range, deformation will occur in the manifold inlet / outlet hole 114, or a gap will be created in the middle of the sub-gasket line, allowing reaction gas and cooling water to flow into the gap, making it difficult to ensure airtightness.

[0061] In another example, the gasket line 123 satisfies the following general formula 2.

[0062] [General formula 2]

[0063] (B-(B×0.2))2 ≦ C ≦ (B+(B×0.2))2

[0064] 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.

[0065] In other words, 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. By the pitch C of the support gasket line satisfying the above range, deformation of the manifold inlet / outlet hole 114 is prevented, airtightness is ensured, and the flow rate of the injected and discharged reaction gas can be distributed uniformly. On the other hand, if the pitch C of the support gasket line is below the lower limit or above the upper limit of the above range, deformation will occur in the manifold inlet / outlet hole 114, or a gap will be created in the middle of the sub-gasket line, allowing reaction gas and cooling water to flow into the gap, making it difficult to ensure airtightness.

[0066] For example, the width B of the manifold gasket line may be 2 mm to 5 mm, specifically, 3 mm to 4 mm. By the manifold gasket line width B being within the aforementioned range, deformation of the manifold inlet / outlet hole 114 is prevented, airtightness is ensured, and the flow rate of the reaction gas to be injected and discharged can be uniformly distributed. On the other hand, if the manifold gasket line width B is below the lower limit or above the upper limit of the aforementioned range, deformation will occur in the manifold inlet / outlet hole 114, or a gap will be created in the middle of the sub-gasket line, allowing reaction gas and cooling water to flow into the gap, making it difficult to ensure airtightness.

[0067] In a further example, the support gasket line 123 satisfies the following general formula 3.

[0068] [General formula 3]

[0069] (B-(B×0.5))2 ≦ D ≦ (B+(B×0.5))2

[0070] In the above general formula 3, D is the length of the gasket line and B is the width of the manifold gasket line.

[0071] In other words, 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. By the length D of the support gasket line satisfying the above range, deformation of the manifold inlet / outlet hole 114 is prevented, airtightness is ensured, and the flow rate of the reaction gas to be injected and discharged can be distributed uniformly. On the other hand, if the length D of the support gasket line is less than the lower limit or more than the upper limit of the above range, deformation will occur in the manifold inlet / outlet hole 114, or a gap will be created in the middle of the sub-gasket line, allowing reaction gas and cooling water to flow into the gap, making it difficult to ensure airtightness.

[0072] In a further example, the thickness of the support gasket line 123 is not particularly limited, as it can be controlled by the material properties of the gas diffusion layer described later.

[0073] Furthermore, multiple support gasket lines 123 may be formed further, extending from the manifold gasket line 121 located on the inner edge of each of the pair or more first reaction gas manifolds 1131 toward the reaction channel 1111 or toward the pair or more first reaction gas manifolds 1131. By further forming multiple support gasket lines 123 in the aforementioned locations, deformation of the manifold inlet / outlet holes 114 can be prevented when stacking the fuel cell cells described later.

[0074] In one example, the metal separation plate may further include a metal coating layer (not shown) or a surface modification layer (not shown) formed on the surface of the metal separation plate body 11, or on the surface of the metal separation plate body 11 on which the gasket line 12 is formed. Specifically, if the metal coating layer or the surface modification layer is formed on the metal separation plate body 11 before the gasket line 12 is formed, the manufactured metal separation plate may have the metal coating layer or surface modification layer formed only on the surface of the metal separation plate body 11. In contrast, if the metal coating layer or the surface modification layer is formed after the gasket line 12 is formed on the metal separation plate body 11, the manufactured metal separation plate may have the metal coating layer or the surface modification layer formed on the surface of the metal separation plate body 11 on which the gasket line 12 is formed. By further including the metal coating layer or the surface modification layer formed on the aforementioned surface, the metal separation plate can ensure excellent corrosion resistance and electrical conductivity.

[0075] In this case, the metal coating layer may include one or more precious metal particles and a passivation film formed between the one or more precious metal particles.

[0076] For example, the noble metal particles 1231 may be one or more selected from gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), and iridium (Ir). By including the aforementioned noble metal particles, the metal coating layer can ensure excellent corrosion resistance and electrical conductivity.

[0077] The passive coating can be formed on the surface of the metal separation plate body 11 where one or more of the precious metal particles do not come into contact with each other, or on the surface of the metal separation plate body 11 on which the gasket line 12 is formed. By forming the passive coating at the aforementioned location, it is possible to prevent oxygen from entering the interior of the metal separation plate body 11 on which the passive coating is formed, thereby preventing rust from occurring.

[0078] In one example, the thickness of the passivation film may be less than the length of the noble metal particles in the thickness direction. By making the thickness of the passivation film less than the length of the noble metal particles in the thickness direction, excellent corrosion resistance and electrical conductivity can be ensured.

[0079] Furthermore, if the metal separation plate body 11 is made of stainless steel containing chromium, and the surface of the metal separation plate body 11 is exposed to the outside, an extremely thin Cr2O3 passivation film with a thickness of 1 nm to 5 nm may naturally form on the surface, and if the passivation film is modified, a surface modification layer may be formed. In this case, the physical properties of each component contained in the metal separation plate body 11 are known in the industry, so they will be omitted.

[0080] This application also relates to a fuel cell cell. The fuel cell cell includes the aforementioned metal separator plate, and the specific details of the metal separator plate described below are omitted because the same information as described for the metal separator plate applies to it.

[0081] Figure 6 is an illustrative side view showing a fuel cell according to one embodiment of the present application. Figure 7 is an illustrative top view showing a fuel cell before the metal separation plates are laminated, according to one embodiment of the present application. As shown in Figure 6, the fuel cell includes a membrane electrode assembly 2 and a pair of the aforementioned metal separation plates 1. By including the aforementioned pair of metal separation plates, the fuel cell prevents deformation of the manifold inlet / outlet holes during lamination and ensures airtightness.

[0082] The film electrode assembly 2 is a film-like assembly that guides the chemical reaction of the reaction gas supplied from the metal separation plate and converts it into electrical energy, and its outer edge is surrounded by a sub-gasket line 21. In this specification, "surrounded" means that the outer edge located in a direction perpendicular to the stacking direction is surrounded. In this case, the film electrode assembly 2 can be of any type known in the art without particular limitation, as long as its outer edge is surrounded by the sub-gasket line 21.

[0083] The pair of metal separation plates 1 are stacked such that the sub-gasket line 21 of each plate contacts the support gasket line 123, and the reaction surfaces 111 face the lower and upper parts of the film electrode assembly 2. In this case, if the support gasket line 123 formed on each reaction surface 111 of the pair of metal separation plates 1 contacts the sub-gasket line 21, the support gasket lines 123 formed on each reaction surface 111 of the pair of metal separation plates 1 may be arranged to face each other.

[0084] Furthermore, in the fuel cell, the metal separation plate 1 located at the bottom of the membrane electrode assembly 2 may be a hydrogen electrode metal separation plate, and the metal separation plate 1 located at the top of the membrane electrode assembly 2 may be an air electrode metal separation plate.

[0085] In this case, the hydrogen electrode metal separation plate may have the gasket line 12 formed on the surface of the reaction surface 111 of the metal separation plate body 11, but not on the surface of the cooling surface 112, or the gasket line 12 may be formed on the surfaces of both the reaction surface 111 and the cooling surface 112 of the metal separation plate body 11.

[0086] Furthermore, the air electrode metal separator plate may have the gasket line 12 formed on the surface of the reaction surface 111 and the cooling surface 112 of the metal separator plate body 11, or it may be the case that the gasket line 12 is formed on the surface of the reaction surface 111 of the metal separator plate body 11, but the gasket line 12 is not formed on the surface of the cooling surface 112.

[0087] In other words, even if the gasket line 12 is formed on the surface of the cooling surface 112 included in the hydrogen electrode metal separation plate and the gasket line 12 is not formed on the surface of the cooling surface 112 included in the air electrode metal separation plate, or even if the gasket line 12 is formed on the surface of the cooling surface 112 included in the air electrode metal separation plate and the gasket line 12 is not formed on the surface of the cooling surface 112 included in the hydrogen electrode metal separation plate, the airtightness of the cooling surface 112 can be ensured when stacking fuel cell cells as unit cells.

[0088] In one example, as shown in Figures 6 and 7, the fuel cell cell may further include a pair of gas diffusion layers 3 provided between each of the pair of metal separation plates 1 and the membrane electrode assembly 2. In this case, any type known in the art can be used for the gas diffusion layer 3 without limitation, and is not particularly limited.

[0089] This application also relates to a fuel cell stack. The fuel cell stack relates to a fuel cell stack that includes the aforementioned fuel cell as a unit cell, and the specific details of the fuel cell described below are omitted because the same content as described for the fuel cell applies to them.

[0090] As described above, the fuel cell stack includes fuel cell cells as unit cells. By including the fuel cell cells as unit cells in the fuel cell stack, deformation of the separation plate can be prevented when stacking, and airtightness can be ensured. [Explanation of symbols]

[0091] 1: Metal separation plate 11:Metal separation plate body 111: Reaction surface 1111: Reaction channel 112: Cooling surface 1121: Cooling channel 113: Manifold section 1131: First reaction gas manifold 1132: Coolant manifold 1133: Second reaction gas manifold 114: Manifold Inlet / Outlet Hole 115: Diffusion channel 12: Gasket line 121: Manifold Gasket Line 122: Flow gasket line 123: Support gasket line 2: Membrane electrode assembly 21: Sub-gasket line 3: Gas diffusion layer A: Width of the support gasket line B: Width of the manifold gasket line C: Pitch of the support gasket line D: Length of the support gasket line

Claims

1. A metal separation plate including a metal separation plate body and a gasket line formed on one or more surfaces of the metal separation plate body, The metal separation plate body has a reaction surface including a reaction channel, A cooling surface located on the opposite side of the reaction surface, including a cooling channel, A manifold section including one or more first reaction gas manifolds, one or more cooling water manifolds, and one or more second reaction gas manifolds, formed on both sides of the reaction channel and the cooling channel, penetrating the reaction surface and the cooling surface, and The manifold comprises one or more second reaction gas manifolds, and a plurality of manifold inlet / outlet holes formed between the reaction channel and the cooling channel, respectively, penetrating the reaction surface and the cooling surface. The aforementioned gasket line is Manifold gasket lines that surround the entire edges of each of the following: one or more first reaction gas manifolds, one or more cooling water manifolds, and one or more second reaction gas manifolds, or manifold gasket lines that surround the entire edges of each of the following: one or more first reaction gas manifolds and one or more second reaction gas manifolds. A flow path gasket line connected to the manifold gasket line, surrounding the reaction channel and multiple manifold inlet / outlet holes, or surrounding the cooling channel and one or more cooling water manifolds, and The manifold gasket lines located on the inner edge of each of one or more pairs of second reaction gas manifolds extend from the reaction flow path or toward each of the one or more pairs of second reaction gas manifolds, and include a plurality of support gasket lines formed between a plurality of manifold inlet and outlet holes, The aforementioned support gasket line is a metal separator plate that satisfies the following general formula 1. [General formula 1] B-(B×0.2) ≦ A ≦ B+ (B×0.2) In the above general formula 1, A is the width of the support gasket line, and B is the width of the manifold gasket line.

2. The metal separator plate according to claim 1, wherein the support gasket line satisfies the following general formula 2. [General formula 2] (B-(B×0.2))2 ≦ C ≦ (B+(B×0.2))2 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.

3. The metal separator plate according to claim 2, wherein the manifold gasket line has a width of 2 mm to 5 mm.

4. The metal separation plate according to claim 1, wherein the gasket line comprises fluorocarbon rubber (FKM), ethylene propylene diene terpolymer (EPDM), or vinyl methyl silicone rubber (LSR).

5. The metal separator plate according to claim 1, wherein a plurality of support gasket lines are further formed, extending from the manifold gasket line located on the inner edge of each of the pair or more first reaction gas manifolds toward the reaction flow path or toward each of the pair or more first reaction gas manifolds.

6. The gasket line is formed on the surface of the reaction surface and the cooling surface of the metal separation plate body, or The metal separation plate according to claim 1, wherein it is formed on the surface of the reaction surface of the metal separation plate body and is not formed on the surface of the cooling surface.

7. The metal separation plate according to claim 1, wherein the metal separation plate body is made of stainless steel, titanium, aluminum, magnesium, or an alloy thereof.

8. The metal separation plate according to claim 1, wherein the metal separation plate body further includes diffusion channels connected to each of the reaction channels and the cooling channels, and extending toward a plurality of manifold inlet and outlet holes.

9. The metal separation plate according to claim 8, further comprising: the surface of the metal separation plate body, or a metal coating layer formed on the surface of the metal separation plate body on which the gasket line is formed; or a surface modification layer.

10. A membrane electrode assembly surrounded by a sub-gasket line; and, A fuel cell cell comprising a pair of metal separation plates according to claim 1, wherein the sub-gasket line is in contact with the support gasket line and the plates are stacked such that their reaction surfaces face the lower and upper parts of the membrane electrode assembly, respectively.

11. The metal separation plate positioned at the bottom of the aforementioned membrane electrode assembly is a hydrogen electrode metal separation plate. The fuel cell cell according to claim 10, wherein the metal separation plate disposed on the upper part of the membrane electrode assembly is an air electrode metal separation plate.

12. The hydrogen electrode metal separation plate has the gasket line formed on the surface of the reaction surface of the metal separation plate body, but the gasket line is not formed on the surface of the cooling surface, or the gasket line is formed on the surfaces of both the reaction surface and the cooling surface of the metal separation plate body. The fuel cell cell according to claim 11, wherein the air electrode metal separator plate has the gasket line formed on the surface of the reaction surface and the cooling surface of the metal separator plate body, or the gasket line is formed on the surface of the reaction surface and the gasket line is not formed on the surface of the cooling surface of the metal separator plate body.

13. A fuel cell stack comprising the fuel cell cell described in claim 10 as a unit cell.

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