Integrated unit cell for fuel cell

Abstract

The present invention provides an integrated unit cell for a fuel cell stack, comprising: an insert composed of a membrane electrode assembly and a pair of gas diffusion layers provided on opposite surfaces of the membrane electrode assembly; a frame in the form of a sheet disposed to surround the insert periphery at an outer boundary region of the insert and bonded to any one of the opposing surfaces of the insert periphery at an interface thereof by a first adhesive; and a pair of separators disposed on opposite surfaces of the frame, respectively, and bonded to the opposite surfaces of the frame by a second adhesive member.

Description

Technical Field

[0001] The present invention relates to an integrated unit cell for a fuel cell. Background Art

[0002] A fuel cell is a power generation device that converts the chemical energy of a fuel into electrical energy through an electrochemical reaction within a cell stack. This power generation device can be used in industry, construction, aviation, household and vehicle applications to supply driving power, as well as to power small electronic products (such as handheld devices). Recently, as an efficient and clean energy source, its scope of use is gradually expanding.

[0003] A typical fuel cell unit cell has a membrane electrode assembly (MEA) located at the innermost part, wherein the membrane electrode assembly is composed of a polymer electrolyte membrane through which hydrogen ions (protons) can pass, and an anode and a cathode as catalyst layers, which are coated on opposite surfaces of the electrolyte membrane to allow hydrogen and oxygen to react.

[0004] In addition, a gas diffusion layer (GDL) is stacked outside the membrane electrode assembly, ie, outside the anode and cathode, and a separator forming a flow field for supplying fuel and discharging water generated by the reaction is located outside the gas diffusion layer.

[0005] The fuel cell stack is formed by stacking a plurality of unit cells configured as above in series to generate a desired level of output from the fuel cell. In the fuel cell stack, end plates are attached to the outermost of the plurality of unit cells to support and fix the unit cells.

[0006] Meanwhile, conventionally, a membrane electrode gasket assembly (MEGA) in which a membrane electrode assembly and a gasket are integrated together is manufactured and used for maintaining airtightness of unit cells and facilitating a stacking process.

[0007] Furthermore, an integrated frame in which a power generation assembly (EGA) (or a membrane electrode gas diffusion layer assembly) in which a gas diffusion layer is bonded to the membrane electrode assembly is integrated with a gasket has recently been studied.

[0008] One of the results of this research is the fabrication of an elastomeric frame surrounding the periphery of the membrane electrode gasket assembly (MEGA).

[0009] However, for the elastomer frame, a sheet frame is manufactured using thermoplastic elastomer (TPE) and then combined with the membrane electrode gasket assembly (MEGA) by hot pressing. At this time, there is a problem that the membrane electrode gasket assembly (MEGA) is damaged or the elastomer frame is deformed due to the heat and pressure provided during the hot pressing for combining.

[0010] In addition, since the elastomer frame is bonded to the separator made of a metal material by thermal compression, there is a problem that the bonding between the separator and the elastomer frame cannot reach a desired level. As a result, when a fuel cell stack is manufactured by stacking unit cells, problems related to leveling the unit cells occur.

[0011] At the same time, in the case of manufacturing and using a membrane electrode gasket assembly (MEGA), costs can be reduced by reducing the amount of electrolyte membrane used, but when a battery stack is manufactured by simply stacking several components, the battery assembly tolerance increases, and it is difficult to replace only the batteries within the battery stack that are judged to be defective, and improving the battery stack productivity is limited.

[0012] The matters described above as background technology are only used to facilitate a better understanding of the background of the embodiments of the present invention, and should not be regarded as an admission that they correspond to the prior art known to ordinary technicians in the field. Summary of the invention

[0013] The present invention relates to an integrated unit cell for a fuel cell. Detailed description of the invention relates to an integrated unit cell for a fuel cell in which an insert and a separator are integrated using a frame formed into a three-dimensional structure.

[0014] An embodiment of the present invention provides an integrated unit cell for a fuel cell in which an insert is integrated with a separator using a frame formed into a three-dimensional structure.

[0015] The technical objectives that can be achieved by the embodiments of the present invention are not limited to the above-mentioned technical objectives, and other technical objectives not mentioned above can be clearly understood by ordinary technicians in the field to which the present invention belongs from the description of the present invention.

[0016] An integrated unit cell for a fuel cell stack according to an embodiment is an integrated unit cell suitable for a fuel cell stack, and includes: an insert, which is composed of a membrane electrode assembly and a pair of gas diffusion layers respectively arranged on two opposite surfaces of the membrane electrode assembly; a frame in the form of a sheet, the frame is arranged to surround the periphery of the insert in the outer boundary area of ​​the insert, and is bonded to any one of the two opposite surfaces of the periphery of the insert at its interface by a first adhesive; and a pair of separators, which are respectively arranged on the two opposite surfaces of the frame and bonded to the two opposite surfaces of the frame by a second adhesive.

[0017] A bonding portion bonded to either of two opposing surfaces of the insert is formed by forming a reaction zone through hole in a frame where the insert is placed and forming a step portion along the inner peripheral surface of the reaction zone through hole in a manner having a level difference with the surface.

[0018] Any one of a pair of gas diffusion layers of the insert is formed to have the same size as the membrane electrode assembly, and the other of the pair of gas diffusion layers is formed to be smaller than the membrane electrode assembly, so that the periphery of the membrane electrode assembly is exposed and the exposed periphery is bonded to the bonding portion by an adhesive.

[0019] In the center of the frame, a reaction zone through hole is formed, and an insert is disposed in the reaction zone through hole. On one side of the frame, a plurality of first manifold through holes are formed, through which the first or second reaction gas flows in or out, and on the other side of the frame, a plurality of second manifold through holes are formed, through which the first or second reaction gas flows in or out. On one surface of the frame, a first reaction gas inflow channel through which the reaction gas flows is formed between any one of the first manifold through holes and the reaction zone through hole, and a first reaction gas outflow channel through which the first reaction gas flows is formed between the reaction zone through hole and any one of the second manifold through holes. On the other surface of the frame, a second reaction gas inflow channel through which the reaction gas flows is formed between another second manifold through hole and the reaction zone through hole, and a second reaction gas outflow channel through which the second reaction gas flows is formed between the reaction zone through hole and another first manifold through hole.

[0020] Each of the pair of partitions has a plurality of third manifold through-holes formed on one side and communicating with the plurality of first manifold through-holes and a plurality of fourth manifold through-holes formed on the other side and communicating with the plurality of second manifold through-holes.

[0021] A pair of partitions includes a first partition bonded to one surface of a frame and a second partition bonded to the other surface of the frame, the first partition having a first passage tunnel, each of the first passage tunnels being formed in the form of a tunnel through which a first reaction gas flows and the first passage tunnels overlapping with a first reaction gas inflow channel and a first reaction gas outflow channel, and the second partition having a second passage tunnel, each of the second passage tunnels being formed in the form of a tunnel through which a second reaction gas flows and the second passage tunnels overlapping with a second reaction gas inflow channel and a second reaction gas outflow channel.

[0022] On one surface of the frame, a first bonding groove portion is formed in the form of a groove of a closed structure, which is formed to surround the reaction zone through hole, a plurality of first manifold through holes, and a plurality of second manifold through holes. On the other surface of the frame, a second bonding groove portion is formed in the form of a groove of a closed structure, which is formed to surround the reaction zone through hole, a plurality of first manifold through holes, and a plurality of second manifold through holes, and bonding members are provided in the first bonding groove portion and the second bonding groove portion.

[0023] The first adhesive groove portion and the second adhesive groove portion are formed at positions symmetrical to each other based on the thickness direction of the frame.

[0024] The adhesive member disposed in the first adhesive groove portion and the second adhesive groove portion does not contact the insert member and is disposed on the frame or the pair of partition plates.

[0025] A pair of partitions includes a first partition bonded to one surface of a frame and a second partition bonded to the other surface of the frame. The first partition has a first adhesive forming portion, the first adhesive forming portion is formed toward the frame to overlap with the first adhesive groove portion, and the first adhesive forming portion and the first adhesive groove portion are bonded and sealed by an adhesive. The second partition has a second adhesive forming portion, the second adhesive forming portion is formed toward the frame to overlap with the second adhesive groove portion, and the second adhesive forming portion and the second adhesive groove portion are bonded and sealed by an adhesive.

[0026] The depths of the first reaction gas inflow channel and the first reaction gas outflow channel formed on one surface of the frame are deeper than the depth of the first bonding forming portion formed on the first partition, and the depths of the second reaction gas inflow channel and the second reaction gas outflow channel formed on the other surface of the frame are deeper than the depth of the second bonding forming portion formed on the second partition.

[0027] The widths of the first adhesive forming portion and the second adhesive forming portion are respectively smaller than the widths of the first adhesive groove portion and the second adhesive groove portion.

[0028] The first adhesive forming portion of the first separator and the second adhesive forming portion of the second separator are formed at positions overlapping each other.

[0029] Any one of the first adhesive forming portion of the first separator and the second adhesive forming portion of the second separator is provided with a gasket applied to a surface opposite to a surface provided with the adhesive member to form an airtight line for sealing the coolant.

[0030] On one side of the frame, a first coolant manifold through-hole through which the coolant flows in or is discharged is formed, and on the other side of the frame, a second coolant manifold through-hole through which the coolant flows in or is discharged is formed. Each of the pair of partitions has a third coolant manifold through-hole formed on one side and communicating with the first coolant manifold through-hole and a fourth coolant manifold through-hole formed on the other side and communicating with the second coolant manifold through-hole.

[0031] In a pair of partitions, a coolant inflow region through which the coolant flows is formed between the first coolant manifold through-hole and the reaction zone through-hole, and a coolant outflow region through which the coolant flows is formed between the reaction zone through-hole and the second coolant manifold through-hole.

[0032] A pair of partitions are formed so that regions forming a coolant inflow region and a coolant outflow region are in contact with two opposing surfaces of the insert.

[0033] The size of the edge of the frame is equal to or greater than the size of a pair of partitions.

[0034] The frame is made of a 40x10 -6 / ℃ or below engineering plastics or super engineering plastics.

[0035] The frame is formed into a three-dimensional structure by injection molding, injection / compression hybrid molding, compression molding or 3D printing.

[0036] According to the embodiment of the present invention, the following effects can be expected.

[0037] First, there is an advantage of reducing unit cell assembly tolerance compared to a conventional unit cell structure manufactured by simply stacking components of unit cells.

[0038] Second, there is an advantage in that the airtightness of the reaction surface can be ensured without a separate sealing member, and therefore, since no sealing member is required, the material cost can be reduced, and since no sealing member molding process or the like is required, the manufacturing cost can be reduced.

[0039] Third, it is advantageous in that since moisture generated in the cell reaction region can be fundamentally prevented from diffusing to the outside of the cell through the electrolyte membrane, electrical short circuits between the cells can be prevented, and it also has the effect of preventing the outer casing of the battery stack from corroding due to moisture.

[0040] Fourthly, since it is not necessary to use an electrolyte membrane in regions other than the unit cell reaction region, there is an effect of reducing material costs.

[0041] Fifth, the production cycle time of the battery stack is shortened, which is conducive to the large-scale production of fuel cell stacks.

[0042] Sixth, the use of integrated unit cells can advantageously facilitate the replacement of unit cells that have developed specific defects during the stack manufacturing process or fuel cell operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is an exploded perspective view showing an integrated unit cell for a fuel cell stack according to an embodiment of the present invention.

[0044] Figure 2A and 2B is a view showing a frame of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention.

[0045] Figure 3is a view showing a reaction surface of a first separator of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention.

[0046] Figure 4A is a view showing a reaction surface of a second separator of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention.

[0047] Figure 4B is a view showing a cooling surface of a second separator of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention.

[0048] Figure 5 FIG. 1 is a diagram showing an integrated unit cell for a fuel cell stack according to an embodiment of the present invention. Figure 2A and 2B A cross-sectional view taken along line AA in FIG.

[0049] Figure 6 FIG. 1 is a diagram showing an integrated unit cell for a fuel cell stack according to an embodiment of the present invention. Figure 2A and 2B A cross-sectional view taken along line BB in FIG.

[0050] Fig. 7A is an exploded perspective view showing a region through which a reaction gas flows in an integrated unit cell for a fuel cell stack according to an embodiment of the present invention.

[0051] Figure 7B It is shown Fig. 7A A cross-sectional view of a region in which a first reaction gas outflow channel is formed.

[0052] Fig. 8A is an exploded perspective view showing a region through which a reaction gas flows in an integrated unit cell for a fuel cell stack according to another embodiment of the present invention.

[0053] Figure 8B It is shown Fig. 8A A cross-sectional view of a region in which a first reaction gas outflow channel is formed.

[0054] Fig. 9 is a view showing a region through which a first reaction gas flows in an integrated unit cell for a fuel cell stack according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] Hereinafter, exemplary embodiments disclosed herein will be described with reference to the accompanying drawings, wherein the same or similar components are given the same reference numerals regardless of the reference numerals, and description thereof will not be repeated.

[0056] The suffixes of components used in the following description, such as "module", "unit", "part" and "section", are given and used only for the convenience of writing the specification. They can be replaced with each other and they themselves have no distinguishable meanings or functions.

[0057] When describing the embodiments disclosed herein, it should be noted that detailed descriptions of related known technologies may be omitted herein to avoid confusing the key points of the embodiments of the present invention. In addition, the accompanying drawings are intended to help better understand the examples disclosed herein, and the technical spirit disclosed herein is not limited by the accompanying drawings, but should be interpreted as including all modifications, equivalents and alternatives within the technical ideas and technical scope of the embodiments of the present invention.

[0058] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components should not be limited by these terms. The above terms are used only to distinguish one component from another.

[0059] Furthermore, when a component is referred to as being “connected to” or “coupled to” another element, it should be understood that the component may be directly connected to or coupled to the other component, or any intervening components may also exist therebetween. Conversely, when a component is referred to as being “directly connected to” or “directly coupled to” another component, it should be understood that there are no other elements therebetween.

[0060] Unless the context clearly indicates otherwise, a singular form may include a plural form.

[0061] Terms such as "include (or include)", "have (or have)", etc. are intended to indicate the existence of the features, quantities, steps, operations, components, parts or their combinations written in the following description, and therefore should not be understood as excluding in advance the possibility of the existence or addition of one or more different features, quantities, steps, operations, components, parts or their combinations.

[0062] Figure 1 is an exploded perspective view showing an integrated unit cell for a fuel cell stack according to an embodiment of the present invention, Figure 2A and 2B is a view showing a frame of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention, Figure 3 is a view showing a reaction surface of a first separator of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention, Figure 4A is a view showing a reaction surface of a second separator of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention, Figure 4B is a view showing a cooling surface of a second separator of an integrated unit cell for a fuel cell stack according to an embodiment of the present invention, Figure 5FIG. 1 is a diagram showing an integrated unit cell for a fuel cell stack according to an embodiment of the present invention. Figure 2A and 2B A cross-sectional view taken along line AA in FIG. Figure 6 FIG. 1 is a diagram showing an integrated unit cell for a fuel cell stack according to an embodiment of the present invention. Figure 2A and 2B A cross-sectional view taken along line BB in FIG. Fig. 7A is an exploded perspective view showing a region through which a reaction gas flows in an integrated unit cell for a fuel cell stack according to an embodiment of the present invention, Figure 7B It is shown Fig. 7A A cross-sectional view of a region in which a first reaction gas outflow channel is formed, Fig. 8A is an exploded perspective view showing a region through which a reaction gas flows in an integrated unit cell for a fuel cell stack according to another embodiment of the present invention, Figure 8B It is shown Fig. 8A A cross-sectional view of a region in which a first reaction gas outflow channel is formed, and Fig. 9 is a view showing a region through which a first reaction gas flows in an integrated unit cell for a fuel cell stack according to an embodiment of the present invention.

[0063] As shown in the figure, the integrated unit cell for a fuel cell stack according to an embodiment of the present invention is an integrated unit cell suitable for a fuel cell stack, and the integrated unit cell includes an insert 100, a frame 200 and a pair of separators 300A, 300B, the insert 100 is composed of a membrane electrode assembly 110 and a pair of gas diffusion layers 120A, 120B arranged on opposite sides thereof, the frame 200 is in the outer boundary of the insert 100, and is bonded to any one of the relative surfaces of the periphery of the insert 100 at the interface therebetween by an adhesive 400, and the pair of separators 300A, 300B are respectively arranged on the relative surfaces of the frame 200, and are respectively bonded to the relative surfaces of the frame 200 by the adhesive 400.

[0064] The insert 100 is an assembly of a membrane electrode assembly 110 and a pair of gas diffusion layers 120A and 120B, and preferably, the gas diffusion layers 120A and 120B are disposed and stacked on one surface and the other surface of the membrane electrode assembly 110, respectively.

[0065] In this regard, the membrane electrode assembly 110 is composed of a polymer electrolyte membrane through which hydrogen ions (protons) can pass and a catalyst layer (i.e., a first electrode layer and a second electrode layer), and the electrode layers are respectively coated on the opposite surfaces of the polymer electrolyte membrane so that the reaction gas (hydrogen and oxygen) can react with it. At this time, the first electrode layer can be an anode and the second electrode layer can be a cathode. Of course, not limited to the foregoing, the first electrode layer can be a cathode, and the second electrode layer can be an anode. In this regard, the first electrode layer and the second electrode layer can be formed to have the same size as the polymer electrolyte membrane. However, in order to firmly bond the first electrode layer and the second electrode layer to the polymer electrolyte membrane and the frame 200, preferably, one of the first electrode layer and the second electrode is formed to have the same size as the polymer electrolyte membrane, and the other of the first electrode layer and the second electrode layer is formed to be slightly smaller than the polymer electrolyte membrane. For example, the first electrode layer can be formed to have the same size as the polymer electrolyte membrane, and the second electrode layer can be formed to be slightly smaller than the polymer electrolyte membrane.

[0066] Meanwhile, in the embodiment, hydrogen gas is referred to as a first reaction gas, and air containing oxygen is referred to as a second reaction gas.

[0067] The gas diffusion layers 120A, 120B allow the first reaction gas or the second reaction gas flowing through the separators 300A, 300B to pass therethrough while diffusing the first or second reaction gas to the membrane electrode assembly 110, and the pair of gas diffusion layers 120A, 120B of the insert 100 is divided into a first gas diffusion layer 120A facing the first electrode layer of the membrane electrode assembly 110 and a second gas diffusion layer 120B facing the second electrode layer of the membrane electrode assembly 110. In this regard, the first gas diffusion layer 120A and the second gas diffusion layer 120B may be formed to have the same size as the membrane electrode assembly. However, in order to firmly bond the first gas diffusion layer 120A and the second gas diffusion layer 120B to the membrane electrode assembly 110 and the frame 200, preferably, one of the first gas diffusion layer 120A and the second gas diffusion layer 120B is formed to have the same size as the membrane electrode assembly 110, and the other of the first gas diffusion layer 120A and the second gas diffusion layer 120B is formed to be slightly smaller than the membrane electrode assembly 110. For example, the first gas diffusion layer 120A is formed to have the same size as the membrane electrode assembly 110 , while the second gas diffusion layer 120B is formed to be slightly smaller than the membrane electrode assembly 110 .

[0068] Therefore, along the periphery of the insert 100 , the first gas diffusion layer 120A is exposed on one side, and the periphery of the membrane electrode assembly 110 is exposed on the other side.

[0069] The frame 200 is formed integrally with the outer area of ​​the insert 100 to serve as a means of maintaining the airtightness of the insert 100 and facilitating the lamination process, and the frame 200 is manufactured into a predetermined 3D shape and is bonded to the insert and a pair of partitions by a separate adhesive 400. In this regard, the frame 200 is preferably made of a hard plastic material having a thermal expansion coefficient similar to that of the partitions 300A and 300B made of a metal material. For example, the plastic material suitable for the frame 200 may be made of a hard plastic material having a thermal expansion coefficient of 40x10 -6 / ℃ or below engineering plastics or super engineering plastics.

[0070] Meanwhile, the frame 200 is preferably formed into a three-dimensional structure through a manufacturing method such as injection molding, injection / compression hybrid molding, compression molding, 3D printing molding, and the like.

[0071] Also, the adhesive member 400 may be an adhesive or an adhesive sheet.

[0072] Meanwhile, the frame 200 is disposed to face any one of the opposite surfaces of the periphery of the insert 100 in the outer boundary region of the insert 100. At this time, the frame 200 is disposed to face the other of the opposite surfaces of the periphery of the insert 100, that is, the portion where the edge of the membrane electrode assembly 110 is exposed. Therefore, the frame 200 is combined with the edge of the membrane electrode assembly 110 of the insert 100 by the adhesive 400.

[0073] Here, the term “outer boundary region” of insert 100 refers to a region including an edge region of insert 100 and a surrounding space, and the term “periphery” of insert 100 refers to an edge region of insert 100 .

[0074] The frame 200 is provided to face the other surface of the periphery of the insert 100 and surround the outer boundary region of the insert 100. In particular, the frame 200 may be provided with a region facing the insert 100 to be closely combined with the insert.

[0075] For example, by forming a reaction zone through hole 201 in the center of the frame 200, the insert 100 is placed in the frame 200, and by forming a step portion along the inner peripheral surface of the reaction zone through hole 201 in a manner having a level difference with the surface in the direction of one of the opposite surfaces of the frame 200, a bonding portion 202 to which the other of the opposite surfaces of the insert 100 is bonded is formed.

[0076] Accordingly, the coupling portion 202 of the frame 200 faces the exposed portion of the membrane electrode assembly 110 at the periphery of the insert 100 and is coupled to the exposed portion through the adhesive 400 to achieve strong coupling and integration with each other.

[0077] In addition, the frame 200 is provided with a plurality of manifold through-holes formed therein for forming a manifold that introduces reaction gas and cooling water into and discharges reaction gas and cooling water from the reaction area formed by the insert 100 (i.e., the membrane electrode assembly 110 and the gas diffusion layers 120A, 120B).

[0078] For example, in the center of the frame 200, a reaction zone through hole 201 in which the insert 100 is placed is formed on one side in the longitudinal direction based on the reaction zone through hole 201, a plurality of first manifold through holes 210a through which the first or second reaction gas flows in or is exhausted are formed, and a plurality of second manifold through holes 210b through which the first or second reaction gas flows in or is exhausted are formed on the other side in the longitudinal direction based on the reaction zone through hole 201.

[0079] In addition, a first coolant manifold through-hole 220 a through which the coolant flows in or is discharged is formed at one side of the frame 200 , and a second coolant manifold through-hole 220 b through which the coolant flows in or is discharged is formed at the other side of the frame 200 .

[0080] Therefore, preferably, based on the direction of gravity from top to bottom, a first manifold through hole 210ai through which the first reaction gas flows in, a first coolant manifold through hole 220a through which the coolant flows in, and a first manifold through hole 210ao through which the second reaction gas is discharged are formed on one side of the frame 200.

[0081] In addition, second manifold through holes 210bi through which the second reaction gas is discharged, second coolant manifold through holes 220b through which the coolant is discharged, and second manifold through holes 210bo through which the first reaction gas is discharged are formed on the other side of the frame 200 based on the gravity direction from top to bottom.

[0082] At the same time, on one surface of the frame 200, a first reaction gas inflow channel 230Ai through which the first reaction gas flows is formed between any one of the first manifold through holes 210a (i.e., the first manifold through hole 210ai through which the first reaction gas flows) and the reaction zone through hole 201, and a first reaction gas outlet channel 230Ao through which the first reaction gas flows is formed between the reaction zone through hole 201 and any one of the second manifold through holes 210b (i.e., the second manifold through hole 210bo through which the first reaction gas is discharged).

[0083] Furthermore, on the other surface of the frame 200, a second reaction gas inflow channel 230Bi through which the second reaction gas flows is formed between another one of the second manifold through holes 210b (i.e., the second manifold through hole 210bi through which the second reaction gas flows) and the reaction zone through hole 201, and a second reaction gas outlet channel 230Bo through which the second reaction gas flows is formed between the reaction zone through hole 201 and another one of the first manifold through holes 210a (i.e., the first manifold through hole 210ao through which the second reaction gas is discharged).

[0084] In this regard, the first reaction gas inflow channel 230Ai, the first reaction gas outflow channel 230Ao, the second reaction gas inflow channel 230Bi, and the second reaction gas outflow channel 230Bo are formed in the form of lined-shaped grooves, each having a predetermined depth on the surface of the frame 200. Here, the depths of the first reaction gas inflow channel 230Ai, the first reaction gas outflow channel 230Ao, the second reaction gas inflow channel 230Bi, and the second reaction gas outflow channel 230Bo formed in the frame 200 may be formed to have the same depth along the flow direction of the reaction gas, or may be formed to have a step along the flow direction of the reaction gas.

[0085] Furthermore, on one surface of the frame 200, the first adhesive groove portion 240A is formed in the form of a groove of a closed structure formed to surround the reaction zone through hole 201, the plurality of first manifold through holes 210a, and the plurality of second manifold through holes 210b, and on the other surface of the frame 200, the second adhesive groove portion 240B is formed in the form of a groove of a closed structure formed to surround the reaction zone through hole 201, the plurality of first manifold through holes 210a, and the plurality of second manifold through holes 210b. Therefore, the adhesive member 400 is disposed in the first adhesive groove portion 240A and the second adhesive groove portion 240B.

[0086] At this time, the adhesive members 400 disposed in the first and second adhesive groove portions 240A and 240B are placed on a frame or a pair of separators through a separate application or attachment process without contacting any of the membrane electrode assembly 110 and the pair of gas diffusion layers 120A and 120B forming the insert 100.

[0087] However, if Figure 3 As shown, when the adhesive member 400 is disposed in the first adhesive groove portion 240A, the adhesive member 400 is disposed in a region other than a region where the first reaction gas inflow channel 230Ai and the first reaction gas outflow channel 230Ao are formed to allow smooth flow of the first reaction gas.

[0088] Similarly, if Figure 4A As shown, when the adhesive member 400 is disposed in the second adhesive groove portion 240B, the adhesive member 400 is disposed in a region other than a region where the second reaction gas inflow channel 230Bi and the second reaction gas outflow channel 230Bo are formed to allow smooth flow of the second reaction gas.

[0089] In addition, the first adhesive groove portion 240A and the second adhesive groove portion 240B are formed at positions symmetrical to each other based on the thickness direction of the frame 200. In this regard, the first adhesive groove portion 240A and the second adhesive groove portion 240B may be formed to have the same width, or one width may be formed to be relatively smaller than the other width. Figure 5 As shown, the width of the first adhesive groove portion 240A formed on one surface of the frame 200 may be formed to be relatively smaller than the width of the second adhesive groove portion 240B formed on the other surface of the frame 200 .

[0090] At the same time, a pair of partitions 300A, 300B are configured to supply the first reaction gas and the second reaction gas to the relative surfaces of the frame 200, respectively, and discharge the product water generated by the reaction of the first reaction gas and the second reaction gas, and they are generally manufactured in a structure in which a boss serving as a support member and a channel (passage) serving as a flow path for the reaction gas and the product water are repeatedly formed in the central area.

[0091] In this regard, the pair of separators 300A, 300B is divided into a first separator 300A facing the first gas diffusion layer 120A and a second separator 300B facing the second gas diffusion layer 120B. Therefore, the first separator 300A becomes an anode separator, and the second separator 300B becomes a cathode separator.

[0092] Each of a pair of partitions 300A, 300B has a boss and a channel formed in a reaction area (in which the insert 100 is disposed), a plurality of third manifold through holes 310Aa and 310Ba formed on one side based on the longitudinal direction of the reaction area and connected to a plurality of first manifold through holes 210a formed in the frame 200, and a plurality of fourth manifold through holes 310Ab and 310Bb formed on the other side based on the longitudinal direction of the reaction area and connected to a plurality of second manifold through holes 210b formed in the frame 200.

[0093] In addition, each of a pair of partitions 300A, 300B has a third coolant manifold through hole 320Aa, 320Ba formed on one side and connected to the first coolant manifold through hole 220a formed in the frame 200, and a fourth coolant manifold through hole 320Ab, 320Bb formed on the other side and connected to the second coolant manifold through hole 220b formed in the frame 200.

[0094] Therefore, preferably, based on the direction of gravity from top to bottom, on each of the sides of a pair of partitions 300A, 300B, third manifold through holes 310Aai, 310Bai through which the first reaction gas flows in, third coolant manifold through holes 320Aa, 320Ba through which the coolant flows in, and third manifold through holes 310Aao, 310Bao through which the second reaction gas is discharged are formed.

[0095] In addition, preferably, based on the direction of gravity from top to bottom, on each of the other sides of a pair of partitions 300A, 300B, fourth manifold through holes 310Abi, 310Bbi through which the second reaction gas is discharged, fourth coolant manifold through holes 320Ab, 320Bb through which the coolant is discharged, and fourth manifold through holes 310Abo, 310Bbo through which the first reaction gas is discharged are formed.

[0096] In addition, each of the pair of partitions 300A, 300B can be formed flat between the area where each manifold through-hole is formed and the reaction area where the channel and the boss are formed, or can have various formation structures to maintain the surface pressure in the corresponding area while promoting the flow of the reaction gas.

[0097] For example, the first separator 300A may have first passage tunnels 330Ai, 330Ao each formed in the form of a tunnel through which the first reaction gas flows and overlaps the first reaction gas inflow channel 230Ai and the first reaction gas outflow channel 230Ao formed on one surface of the frame 200.

[0098] Similarly, the second separator 300B may have second passage tunnels 330Bi, 330Bo each formed in the form of a tunnel through which the second reaction gas flows and overlaps with the second reaction gas inflow channel 230Bi and the second reaction gas outflow channel 230Bo formed on the other surface of the frame 200 .

[0099] In addition, the pair of partitions 300A and 300B may have a forming structure for bonding and sealing with the frame 200 .

[0100] For example, the first separator 300A has a first adhesive forming portion 340A which is formed toward one surface of the frame 200 and overlaps with the first adhesive groove portion 240A formed on the surface of the frame 200. Therefore, the adhesive member 400 is provided between the first adhesive groove portion 240A and the first adhesive forming portion 340A to closely adhere the first adhesive groove portion 240A and the first adhesive forming portion 340A, thereby allowing adhesion and sealing between one surface of the frame 200 and the first separator 300A.

[0101] Similarly, the second separator 300B has a second adhesive forming portion 340B formed toward the other surface of the frame 200 and overlapped with the second adhesive groove portion 240B formed on the other surface of the frame 200. Therefore, the adhesive member 400 is provided between the second adhesive groove portion 240B and the second adhesive forming portion 340B to closely adhere the second adhesive groove portion 240B and the second adhesive forming portion 340B, thereby bonding and sealing the other surface of the frame 200 and the second separator 300B.

[0102] Meanwhile, it is preferred that each of the first adhesive forming portion 340A and the second adhesive forming portion 340B formed on the first separator 300A and the second separator 300B is formed to have a width smaller than that of each of the first adhesive groove portion 240A and the second adhesive groove portion 240B formed in the frame 200. Therefore, when the first separator 300A and the second separator 300B made of a metal material expand or contract according to a temperature change occurring during operation of the fuel cell and an external temperature change, the amount of change can be sufficiently accommodated within the first adhesive groove portion 240A and the second adhesive groove portion 240B formed in the frame 200.

[0103] In addition, it is preferred that the first adhesive forming portion 340A of the first separator 300A and the second adhesive forming portion 340B of the second separator 300B are formed at positions overlapping each other. Therefore, when the frame 200, the first separator 300A and the second separator 300B are bonded to each other by the adhesive member 400, the adhesive member 400 is disposed at the overlapping position so that when the corresponding area P1 is thermally compressed, the area to which heat and pressure are applied can be minimized while making the heat and pressure uniform.

[0104] In addition, the depths of the first reaction gas inflow flow channel 230Ai and the first reaction gas outflow flow channel 230Ao formed on one surface of the frame 200 are formed deeper than the depth of the first adhesion forming part 340A formed on the first separator 300A.

[0105] Similarly, the depths of the second reaction gas inflow flow passage 230Bi and the second reaction gas outflow flow passage 230Bo formed on the other surface of the frame 200 are formed deeper than the depth of the second adhesion forming portion 340B formed on the second separator 300B.

[0106] Therefore, if Fig. 7A and 7BAs shown, even if the first reaction gas inflow channel 230Ai, the first reaction gas outflow channel 230Ao, the second reaction gas inflow channel 230Bi and the second reaction gas outflow channel 230Bo partially overlap with the first bonding forming part 340A and the second bonding forming part 340B, blockage of the first reaction gas inflow channel 230Ai, the first reaction gas outflow channel 230Ao, the second reaction gas inflow channel 230Bi and the second reaction gas outflow channel 230Bo can be avoided.

[0107] Meanwhile, any one of the first adhesive forming part 340A of the first separator 300A and the second adhesive forming part 340B of the second separator 300B may be provided with a gasket 500 applied to a surface opposite to a surface to which the adhesive 400 is applied to form an airtight line for sealing the coolant.

[0108] For example, in the present embodiment, the gasket 500 may be formed on the second adhesion forming portion 340B of the second separator 300B.

[0109] Therefore, the first adhesive forming portion 340A formed on the reaction surface of the first separator 300A is bonded to one surface of the frame 200 through the adhesive member 400, and neither the adhesive member nor the gasket is provided on the cooling surface of the first separator 300A. Also, the second adhesive forming portion 340B formed on the reaction surface of the second separator 300B is bonded to the other surface of the frame 200 through the adhesive member 400, and the gasket 500 is provided on the cooling surface of the second separator 300B, so that when the fuel cell stack is formed, the airtightness of the coolant can be maintained by the gasket 500 in the unit cell and the adjacent first separator 300A.

[0110] At the same time, each of a pair of partitions 300A, 300B is provided with a coolant inflow area 350Ai, 350Bi through which the coolant flows between the first coolant manifold through holes 310Aa, 310Ba and the reaction zone through holes 201, and a coolant outflow area 350Ao, 350Bo through which the coolant flows between the second coolant manifold through holes 310Ab, 310Bb and the reaction zone through holes 201.

[0111] In this regard, Figure 6 As shown, a pair of separators 300A, 300B are formed to contact two opposite surfaces of the insert 100 in regions forming coolant inflow areas 350Ai, 350Bi and coolant outflow areas 350Ao, 350Bo, respectively. Therefore, when the fuel cell stack is constructed, the first separator 300A and the second separator 300B of adjacent unit cells are spaced apart by a predetermined distance, and the coolant flows through the space therebetween.

[0112] Meanwhile, it is preferred that the size of the periphery of the frame 200 is equal to or larger than the size of the periphery of the pair of partitions 300A and 300B, such as Figure 5 As shown. Preferably, it is more acceptable to form the periphery of the frame 200 to have a larger size than the periphery of the pair of separators 300A and 300B. Therefore, at the periphery of the unit battery, since the ends of the peripheries of the first separator 300A and the second separator 300B are located at the inner side of the unit battery than the periphery of the insert 100, it is fundamentally prevented that an electrical short circuit occurs due to contact between the first separator 300A and the second separator 300B when the peripheries are bent.

[0113] Meanwhile, in an embodiment of the present invention, in order to prevent the gasket 500 from being damaged or deformed when a pair of partitions 300A, 300B are bonded to opposite surfaces of the frame 200 by the thermocompression bonding member 400, the placement position of the bonding member 400 may be different from the position where the gasket 500 is formed.

[0114] like Fig. 8A and 8B As shown, although the formation position of the first adhesive forming part 340A formed on the first separator 300A and the formation position of the second adhesive forming part 340B formed on the second separator 300B overlap each other, the positions at which the gasket 500 and the adhesive member 400 are bonded while being disposed on the opposite surfaces of the second adhesive forming part 340B of the second separator 300B may be misaligned with each other due to the fact that the width of the first adhesive forming part 340A formed on the first separator 300A is relatively greater than the width of the second adhesive forming part 340B formed on the second separator 300B. Therefore, by disposing the gasket 500 at a position deviated from the area P2 to which the surface pressure is applied, it is possible to prevent the gasket 500 from being damaged or deformed by heat and pressure during the hot pressing of the adhesive member 400.

[0115] Although the embodiments of the present invention have been described with reference to the drawings and the preferred embodiments described above, the embodiments of the present invention are not limited thereto. Therefore, those skilled in the art will make various changes and modifications to the embodiments of the present invention without departing from the scope of the technical ideas of the claims described later.

[0116] The following figure identifiers may be used in conjunction with the figures to describe various features of embodiments of the invention.

[0117] 100: Insert

[0118] 110: Membrane Electrode Assembly

[0119] 120A, 120B: Gas diffusion layer

[0120] 200: Framework

[0121] 201: Reaction zone through hole

[0122] 202: Joint

[0123] 210a: First manifold through hole

[0124] 210b: Second manifold through hole

[0125] 220a: First coolant manifold through hole

[0126] 220b: Second coolant manifold through hole

[0127] 230Ai: The first reaction gas flows into the flow channel

[0128] 230Ao: First reaction gas outflow channel

[0129] 230Bi: Second reaction gas flows into the flow channel

[0130] 230Bo: Second reaction gas outflow channel

[0131] 240A: First bonding groove

[0132] 240B: Second bonding groove

[0133] 300A: First separator

[0134] 310a: First manifold through hole

[0135] 310Ab: Second manifold through hole

[0136] 320Aa: Third coolant manifold through hole

[0137] 320Ab: Fourth coolant manifold through hole

[0138] 330A: First Access Tunnel

[0139] 340A: First bonding forming portion

[0140] 350Ai: Coolant inflow area

[0141] 350Ao: Coolant outflow area

[0142] 300B: Second partition

[0143] 310Ba: First manifold through hole

[0144] 310Bb: Second manifold through hole

[0145] 320Ba: Third coolant manifold through hole

[0146] 320Bb: Fourth coolant manifold through hole

[0147] 330B: Second access tunnel

[0148] 340B: Second bonding forming portion

[0149] 350Bi: Coolant inflow area

[0150] 350Bo: Coolant outflow area

[0151] 400: Adhesive parts

[0152] 500: Washer

Claims

1. An integrated unit cell for a fuel cell stack, the integrated unit cell comprising: an insert consisting of a membrane electrode assembly and a pair of gas diffusion layers respectively disposed on two opposite surfaces of the membrane electrode assembly; a frame in the form of a sheet material, the frame being arranged to surround the periphery of the insert at an outer boundary region of the insert and being bonded to any one of two opposite surfaces of the periphery of the insert at an interface thereof by a first adhesive member; as well as A pair of partitions are respectively disposed on two opposite surfaces of the frame and bonded to the two opposite surfaces of the frame through a second adhesive member.

2. The integrated unit cell according to claim 1, wherein: A bonding portion bonded to any one of the two opposing surfaces of the insert is defined by a reaction zone through hole formed in the frame where the insert is placed and a step portion formed along the inner peripheral surface of the reaction zone through hole in a manner having a level difference with the surface.

3. The integrated unit cell according to claim 2, wherein: The size of the first gas diffusion layer of the pair of gas diffusion layers of the insert is the same as that of the membrane electrode assembly, and the second gas diffusion layer of the pair of gas diffusion layers is smaller than the membrane electrode assembly, so that the periphery of the membrane electrode assembly is exposed and the exposed periphery is bonded to the bonding portion by the first adhesive.

4. The integrated unit battery according to claim 1, further comprising: a reaction zone through hole formed in the center of the frame, wherein the insert is placed in the reaction zone through hole; a plurality of first manifold through-holes formed on a first side of the frame, wherein the plurality of first manifold through-holes are configured to allow a first reaction gas or a second reaction gas to flow in or be exhausted therethrough; a plurality of second manifold through-holes formed on a second side of the frame, wherein the plurality of second manifold through-holes are configured to allow the first reaction gas or the second reaction gas to flow in or be exhausted therethrough; a first reaction gas inflow channel formed on the first surface of the frame and located between any one of the plurality of first manifold through-holes and the reaction zone through-hole, wherein the first reaction gas inflow channel is configured to allow the first reaction gas to flow therethrough; a first reaction gas outflow channel formed on the first surface of the frame and located between the reaction zone through-hole and any one of the plurality of second manifold through-holes, wherein the first reaction gas outflow channel is configured to allow the first reaction gas to flow therethrough; a second reaction gas inflow channel formed on the second surface of the frame and located between another second manifold through-hole and the reaction zone through-hole, wherein the second reaction gas inflow channel is configured to allow the second reaction gas to flow therethrough; and A second reaction gas outflow channel is formed on the second surface of the frame and is located between the reaction zone through hole and another first manifold through hole, wherein the second reaction gas outflow channel is configured to allow the second reaction gas to flow therethrough.

5. The integrated unit cell according to claim 4, wherein: Each of the pair of separators comprises: a plurality of third manifold through-holes formed on the first side and communicating with the plurality of first manifold through-holes; and A plurality of fourth manifold through holes are formed on the second side and communicated with the second manifold through holes.

6. The integrated unit cell according to claim 5, wherein: The pair of partitions includes a first partition coupled to a first surface of the frame and a second partition coupled to a second surface of the frame; the first separator includes first passage tunnels, each of the first passage tunnels having the form of a tunnel through which the first reaction gas can flow, the first passage tunnels overlapping the first reaction gas inflow flow channel and the first reaction gas outflow flow channel; and The second partition plate includes second passage tunnels, each of which has the form of a tunnel through which the second reaction gas can flow, the second passage tunnels overlapping the second reaction gas inflow flow channel and the second reaction gas outflow flow channel.

7. The integrated unit cell according to claim 5, wherein: A first coolant manifold through-hole is formed at the first side of the frame, wherein the first coolant manifold through-hole is configured to allow coolant to flow in or out therethrough; A second coolant manifold through-hole is formed at the second side of the frame, wherein the second coolant manifold through-hole is configured to allow the coolant to flow in or out therethrough; and Each of the pair of separators comprises: a third coolant manifold through-hole formed on the first side and communicating with the first coolant manifold through-hole; and A fourth coolant manifold through-hole is formed on the second side and communicates with the second coolant manifold through-hole.

8. The integrated unit battery according to claim 7, further comprising: a coolant inflow region formed in the pair of partitions and located between the first coolant manifold through-holes and the reaction zone through-holes, wherein the coolant inflow region is configured to flow a coolant therethrough; and A coolant outflow region is formed in the pair of partitions and is located between the reaction region through-hole and the second coolant manifold through-hole, wherein the coolant inflow region is configured to flow a coolant therethrough.

9. The integrated unit cell according to claim 8, wherein: The pair of partition plates are disposed so that a region forming the coolant inflow region and a region forming the coolant outflow region are in contact with two opposing surfaces of the insert.

10. The integrated unit battery according to claim 4, further comprising: A first bonding groove portion is formed on the first surface of the frame in the form of a groove of a closed structure surrounding the reaction zone through-hole, the plurality of first manifold through-holes, and the plurality of second manifold through-holes; a second bonding groove portion formed on the second surface of the frame in the form of a groove of a closed structure surrounding the reaction region through-hole, the plurality of first manifold through-holes, and the plurality of second manifold through-holes; and The second adhesive member is disposed in the first adhesive groove portion and the second adhesive groove portion.

11. The integrated unit cell according to claim 10, wherein: The first bonding groove portion and the second bonding groove portion are formed at positions symmetrical to each other with respect to a thickness direction of the frame.

12. The integrated unit cell according to claim 10, wherein: The second adhesive member provided in the first adhesive groove portion and the second adhesive groove portion does not contact the insert member and is provided on the frame or the pair of partition plates.

13. The integrated unit cell according to claim 10, wherein: The pair of partitions includes a first partition coupled to the first surface of the frame and a second partition coupled to the second surface of the frame; The first separator includes a first adhesive forming portion formed toward the frame in a manner overlapping with the first adhesive groove portion so that adhesion and sealing between the first adhesive forming portion and the first adhesive groove portion are achieved by one of the second adhesive members; and The second separator includes a second adhesive forming portion formed toward the frame in a manner overlapping with the second adhesive groove portion so that adhesion and sealing between the second adhesive forming portion and the second adhesive groove portion is achieved by the other of the second adhesive members.

14. The integrated unit cell according to claim 13, wherein: The depth of the first reaction gas inflow channel and the first reaction gas outflow channel formed on the first surface of the frame is deeper than the depth of the first adhesion forming portion formed on the first separator; as well as The depth of the second reaction gas inflow channel and the second reaction gas outflow channel formed on the second surface of the frame is deeper than the depth of the second adhesion forming portion formed on the second separator.

15. The integrated unit cell according to claim 13, wherein: The widths of the first adhesion forming portion and the second adhesion forming portion are respectively smaller than the widths of the first adhesion groove portion and the second adhesion groove portion.

16. The integrated unit cell according to claim 13, wherein: The first adhesion forming portion of the first separator and the second adhesion forming portion of the second separator are formed at positions overlapping each other.

17. The integrated unit cell according to claim 13, wherein: The first adhesive forming portion of the first separator or the second adhesive forming portion of the second separator is provided with a gasket applied to a surface opposite to a surface on which the second adhesive member is provided to form an airtight line for sealing a coolant.

18. The integrated unit cell according to claim 1, wherein: The size of the periphery of the frame is greater than or equal to the size of the pair of partitions.

19. The integrated unit cell according to claim 1, wherein: The frame includes a thermal expansion coefficient of 40 x 10 -6 / ℃ or below engineering plastics or super engineering plastics.

20. A method of forming an integrated unit cell for a fuel cell stack, the method comprising the steps of: constructing an insert having a membrane electrode assembly and a pair of gas diffusion layers disposed on two opposing surfaces of the membrane electrode assembly; forming a frame in the form of a sheet, the frame being arranged to surround the periphery of the insert at an outer boundary region of the insert and being bonded to any one of two opposite surfaces of the periphery of the insert at an interface thereof by a first adhesive, wherein forming the frame comprises forming the frame into a three-dimensional structure by injection molding, injection / compression hybrid molding, compression molding, or 3D printing; as well as A pair of spacers are respectively disposed on two opposite surfaces of the frame and bonded to the two opposite surfaces of the frame by a second adhesive member.

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