Fuel cell

Abstract

A fuel cell includes a cell stack including a plurality of unit cells stacked in a first direction, a first end plate and a second end plate disposed at both ends of the cell stack, and a plurality of fasteners fastening the plurality of unit cells in the first direction. The plurality of fasteners includes a first fastener provided on an edge portion of the cell stack in a manner extending in a first direction, and a second fastener provided on at least one of an upper surface and a lower surface of the cell stack in a manner extending in the first direction. The first fastener includes a first portion disposed at a position adjacent to the edge portion on or under the cell stack, and a second portion bent from the first portion to be disposed at a side portion of the cell stack.

Description

Technical Field

[0001] The present invention relates to fuel cells. Background Art

[0002] A fuel cell can generate electrical energy through an oxidation reaction of hydrogen as a reactant gas and a reduction reaction of oxygen as a reactant gas. So far, a unit cell included in a fuel cell may include a separator, a gas diffusion layer (GDL), and a membrane electrode assembly (MEA). Hundreds of unit cells may be stacked to obtain a desired output.

[0003] One of the most important factors in manufacturing a fuel cell is to ensure stability in the event of a collision. If current leaks from the cell stack included in the fuel cell to the high-voltage power generation system due to a collision, there is a risk of a high-voltage electric shock accident. The fuel cell may include a housing or an operating device to protect a plurality of unit cells.

[0004] Vehicles equipped with fuel cells may face various collision accidents. Sometimes a low-speed collision accident occurs in which the power supply does not need to be interrupted. If a battery stack in which hundreds of batteries are stacked in the longitudinal direction is subjected to a lateral impact due to a collision or the like, slippage may occur, causing the batteries to be misaligned or short-circuited. Therefore, various studies are being conducted with the goal of solving the current problem.

[0005] The information contained in this Background of the Invention is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art. Summary of the invention

[0006] Various aspects of the present invention are directed to a fuel cell that substantially obviates one or more problems due to limitations and disadvantages of the related art.

[0007] Embodiments of the present invention provide a fuel cell that is resistant to external impact and is reduced in size.

[0008] However, objects to be achieved by the exemplary embodiments are not limited to the above objects, and other objects not mentioned herein may be clearly understood by those skilled in the art from the following description.

[0009] A fuel cell according to various exemplary embodiments of the present invention may include: a cell stack, a first end plate and a second end plate, and a plurality of clamping members, wherein the cell stack includes a plurality of unit cells stacked in a first direction, the first end plate and the second end plate are disposed at both ends of the cell stack, and the fasteners are configured to fasten the plurality of unit cells in the first direction and to be spaced apart from each other in a second direction intersecting the first direction. The plurality of fasteners may include a first fastener disposed on an edge portion of the cell stack and extending in the first direction and a second fastener disposed on at least one of the cell stack above or below the cell stack and extending in the first direction. The first fastener may include a first portion disposed on the cell stack or below the cell stack at a position adjacent to the edge portion, and a second portion bent from the first portion and disposed on a side portion of the cell stack. The first portion may include a first metal portion and a first insulating portion disposed between the first metal portion and the cell stack, and the second portion may include a second insulating portion disposed on a side portion of the cell stack.

[0010] In an exemplary embodiment of the present invention, the first insulating portion and the second insulating portion may be formed integrally with each other.

[0011] In an exemplary embodiment of the present invention, the second fastener may include a second metal part and a third insulating part disposed between the second metal part and the battery stack.

[0012] In an exemplary embodiment of the present invention, the second portion may cover the entire area of ​​the side of the battery stack.

[0013] In an exemplary embodiment of the present invention, the second portion may include an impact mitigation pattern.

[0014] In an exemplary embodiment of the present invention, the second portion may cover a portion of a side portion of the battery stack.

[0015] In an exemplary embodiment of the present invention, the second portion may be formed such that a thickness thereof in the second direction gradually decreases in a direction away from the first portion.

[0016] In an exemplary embodiment of the present invention, the battery stack may include: an upper surface, a lower surface (low surface) opposite to the upper surface in a third direction intersecting both the first direction and the second direction, a first side surface located between the upper surface and the lower surface, and a second side surface opposite to the first side surface in the second direction. The plurality of fasteners may include: a first fastening strip disposed on a boundary where the upper surface and the first side surface meet each other, a second fastening strip disposed on a boundary where the upper surface and the second side surface meet each other, a third fastening strip disposed on a boundary where the lower surface and the first side surface meet each other, a fourth fastening strip disposed on a boundary where the lower surface and the second side surface meet each other, a fifth fastening strip disposed on the upper surface, and a sixth fastening strip disposed on the lower surface.

[0017] In an exemplary embodiment of the present invention, each of the first, second, third, and fourth fastening strips may belong to the first fastening member, and each of the fifth and sixth fastening strips may belong to the second fastening member.

[0018] In an exemplary embodiment of the present invention, each of the first and fourth fastening strips may belong to the first fastening member, and each of the second, third, fifth, and sixth fastening strips may belong to the second fastening member.

[0019] In an exemplary embodiment of the present invention, each of the second and third fastening strips may belong to the first fastening member, and each of the first, fourth, fifth, and sixth fastening strips may belong to the second fastening member.

[0020] In an exemplary embodiment of the present invention, the elastic modulus of the second insulating portion at 23° C. may be 12 GPa, and the impact strength may be 10 kJ / m 2 The length in the third direction may be 2 mm to 3 mm. The second insulating portion may have a thickness of 15 mm or more at one end abutting against the first metal portion in the second direction, and a thickness of 4 mm or more at the other end in the second direction.

[0021] In an exemplary embodiment of the present invention, the second insulating portions of the first and third fastening strips may be spaced apart from each other in the third direction, and the second and fourth fastening strips may be spaced apart from each other in the third direction.

[0022] In an exemplary embodiment of the present invention, the second insulating portion of the first fastening bar and the second insulating portion of the third fastening bar may be integrally formed with each other, and the second insulating portion of the second fastening bar and the second insulating portion of the fourth fastening bar may be integrally formed with each other.

[0023] In an exemplary embodiment of the present invention, the fuel cell may further include a side cover coupled to the second end plate, and a case coupled to the first end plate and the side cover and surrounding a side portion of the cell stack.

[0024] In an exemplary embodiment of the present invention, the fuel cell may further include a first connecting portion configured to connect the first end plate to one end of each fastener, a second connecting portion configured to connect the second end plate to the other end of each fastener, and a third connecting portion of the second end plate configured to connect the side cover.

[0025] In an exemplary embodiment of the present invention, at least one of the first, second, and third coupling parts may include a flange bolt and a sealing washer disposed between the flange bolt and an insertion hole formed to allow the flange bolt to pass through or be inserted therein.

[0026] In an exemplary embodiment of the present invention, the diameter of the insertion hole is 5 mm or more and the depth is 9 mm or more.

[0027] A fuel cell according to another exemplary embodiment of the present invention may include: a cell stack including a plurality of unit cells stacked in a first direction, a first end plate and a second end plate respectively disposed on a first end portion and a second end portion of the cell stack, a side cover coupled to the second end plate, a housing coupled to the first end plate and the side cover and surrounding a side portion of the cell stack, a first fastener configured to fasten the plurality of unit cells in the first direction and disposed at an edge portion of the cell stack and extending in the first direction, a second fastener configured to fasten the plurality of unit cells in the first direction and disposed on at least one of an upper portion and a lower portion of the cell stack and spaced from the first fastener and extending in the first direction, and a coupling portion configured to couple each of the first and second fasteners to each of the first and second end plates and couple the side cover to the housing. The first fastener may include an insulating portion disposed at the edge portion and extending from an area on an upper portion of the cell stack to an area on a side portion of the cell stack, and a metal portion disposed on a portion of the insulating portion, disposed on an upper portion of the cell stack and coupled to the coupling portion.

[0028] The method and apparatus of the present invention also have other features and advantages, which can be clearly seen from the accompanying drawings or shown in the detailed description of the accompanying drawings, which are incorporated herein and together with the following detailed description are used to explain certain principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are provided here to further understand the present invention, and these drawings are incorporated into this specification to form a part of this application. The accompanying drawings are used to illustrate the embodiments of the present invention and are used to explain the principles of the present invention together with the detailed description. In these drawings:

[0030] Figure 1A is a perspective view of a fuel cell according to an exemplary embodiment of the present invention;

[0031] Figure 1B yes Figure 1A An exploded perspective view of a fuel cell shown;

[0032] Figure 2 yes Figure 1A and Figure 1B A cross-sectional view of a first end plate and a second end plate, a current collector and a cell stack in a fuel cell shown;

[0033] Figure 3A is a diagram showing a plurality of fasteners and an exemplary embodiment Figure 1B A perspective view of a cell stack connection in a fuel cell shown;

[0034] Figure 3B It is shown Figure 3A A front view of a battery stack shown coupled with a plurality of fasteners;

[0035] Figure 4 1 is a diagram showing a plurality of fasteners and a Figure 1B A front view of a cell stack connection in a fuel cell is shown;

[0036] Figure 5A is a perspective view of a first fastener according to an exemplary embodiment of the present invention;

[0037] Figure 5B yes Figure 5A a front view of the first fastener shown;

[0038] Figure 6 is a perspective view of a second fastener according to an exemplary embodiment of the present invention;

[0039] Fig. 7A 1 is a diagram showing a plurality of fasteners and a Figure 1B A perspective view of a cell stack connection in a fuel cell shown;

[0040] Figure 7B yes Fig. 7A a front view of the battery stack and a plurality of fasteners shown;

[0041] Figure 8 is along Figure 1A A cross-sectional view taken along line II' in the illustrated exemplary embodiment;

[0042] Fig. 9 is a cross-sectional view of a fuel cell according to an exemplary embodiment of the present invention;

[0043] Fig.10is a cross-sectional view of a fuel cell according to another exemplary embodiment of the present invention;

[0044] Fig.11 is a cross-sectional view of a fuel cell according to still another exemplary embodiment of the present invention;

[0045] Fig.12 is a perspective view of a fuel cell according to a comparative example;

[0046] Fig.13 is a graphic representation of impulse; and

[0047] Fig.14 is a perspective view of a fuel cell according to another comparative example.

[0048] It is to be understood that the accompanying drawings are not necessarily drawn to scale, but present a somewhat simplified representation of various features to illustrate the basic principles of the present invention. The specific design features of the present invention contained herein, including, for example, specific size, direction, position and shape, will be determined in part by the specific purpose application and use environment.

[0049] In the drawings, reference numbers are used throughout the several views to designate the same or equivalent parts of the present invention. DETAILED DESCRIPTION

[0050] Reference will now be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and described below. Although the present invention will be described in conjunction with exemplary embodiments of the present invention, it will be understood that this description is not intended to limit the present invention to those exemplary embodiments of the present invention. On the other hand, the present invention is intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalents and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0051] The present invention will be described more fully below with reference to the accompanying drawings, in which various exemplary embodiments of the present invention are shown. However, these examples can be implemented in various forms and should not be construed as being limited to the exemplary embodiments described herein. On the contrary, these embodiments are provided to make the present invention clearer and more complete and to more fully convey the scope of the present invention to those skilled in the art.

[0052] It will be understood that when an element is referred to as being 'on' or 'under' another element, it can be directly on / under the element, or one or more intervening elements may be present.

[0053] When an element is referred to as being 'on' or 'under', 'under the element' as well as 'under the element' may be included based on the element.

[0054] Furthermore, relational terms, such as “first,” “second,” “above / upper,” and “below / lower / under,” are used solely to distinguish one object or element from another object or element and do not necessarily require or involve any physical or logical relationship or order between the objects or elements.

[0055] Below, a fuel cell according to an exemplary embodiment will be described with reference to the accompanying drawings. For ease of description, the fuel cell will be described using a Cartesian coordinate system (x-axis, y-axis, z-axis), but other coordinate systems may also be used for description. In the Cartesian coordinate system, the x-axis, y-axis, and z-axis are perpendicular to each other, but the exemplary embodiment is not limited thereto. That is, the x-axis, y-axis, and z-axis may be inclined to intersect each other. Hereinafter, for ease of description, the x-axis direction is referred to as the "first direction", the y-axis direction is referred to as the "second direction", and the z-axis direction is referred to as the "third direction".

[0056] Figure 1A is a perspective view of a fuel cell 100 according to an exemplary embodiment of the present invention, Figure 1B yes Figure 1A An exploded perspective view of a fuel cell 100 is shown.

[0057] Figure 1A and Figure 1B The illustrated fuel cell 100 may include first and second end plates (or press plates or compression plates) 110A and 110B, a cell stack (or power generation module) 122, and a plurality of fasteners 130. In addition, the fuel cell 100 may also include current collectors 112A and 112B.

[0058] The fuel cell 100 may be, for example, a polymer electrolyte membrane fuel cell (or proton exchange membrane fuel cell) (PEMFC), which has been most widely studied as a power source for driving vehicles. However, exemplary embodiments are not limited to any specific form of the fuel cell 100 .

[0059] Figure 2 yes Figure 1A and Figure 1B A cross-sectional view of the first and second end plates 110A, 110B, current collectors 112A and 112B, and a cell stack 122 in the fuel cell 100 is shown.

[0060] refer to Figure 2 The battery stack 122 may include a plurality of unit cells 122-1 to 122-N stacked along a first direction (eg, an x-axis direction). Here, "N" is a positive integer of 1 or greater and may range from tens to hundreds. However, exemplary embodiments are not limited to any specific value of "N".

[0061] Each unit cell 122-n may be configured to generate 0.6 volts to 1.0 volts of electricity, averaging 0.7 volts of electricity. Here, 1≤n≤N. Therefore, "N" may be determined according to the power intensity provided to the load from the fuel cell 100. Here, "load" may refer to a component in a vehicle that requires electricity.

[0062] Each unit cell 122 - n may include a membrane electrode assembly (MEA) 210 , gas diffusion layers (GDL) 222 and 224 , internal gaskets 232 , 234 , and 236 , and separators (or bipolar plates) 242 and 244 .

[0063] The membrane electrode assembly 210 includes a structure in which a catalyst electrode layer where an electrochemical reaction occurs is attached to both sides of an electrolyte membrane through which hydrogen ions move. Specifically, the membrane electrode assembly 210 may include a polymer electrolyte membrane (or proton exchange membrane) 212, a fuel electrode (hydrogen electrode or anode) 214, and an air electrode (oxygen electrode or cathode) 216. In addition, the membrane electrode assembly 210 may further include a sub-gasket 238.

[0064] The polymer electrolyte membrane 212 is provided between the fuel electrode 214 and the air electrode 216 .

[0065] Hydrogen gas as a fuel of the fuel cell 100 may be supplied to the fuel electrode 214 through the first separator 242 , and air containing oxygen as an oxidant may be supplied to the air electrode 216 through the second separator 244 .

[0066] The hydrogen gas supplied to the fuel electrode 214 is decomposed by the catalyst into hydrogen ions (protons) (H + ) and electron (e - ). Individual hydrogen ions may be selectively transferred to the air electrode 216 through the polymer electrolyte membrane 212, and at the same time, electrons may be transferred to the air electrode 216 through the gas diffusion layers 222, 224 and the first separator 242 and the second separator 244 as conductors. In order to achieve the above operation, a catalyst layer may be applied to each of the fuel electrode 214 and the air electrode 216. The movement of the above electrons causes the electrons to flow through the external wire, thereby generating an electric current. That is, the fuel cell 100 can generate electrical energy due to the electrochemical reaction between the hydrogen gas as a fuel and the oxygen contained in the air.

[0067] In the air electrode 216, hydrogen ions supplied through the polymer electrolyte membrane 212 and electrons transferred through the first separator 242 and the second separator 244 meet oxygen in the air supplied to the air electrode 216, thereby generating a reaction of water (hereinafter referred to as "product water" or "condensed water"). The product water generated at the air electrode 216 can penetrate the polymer electrolyte membrane 212 and can be transferred to the fuel electrode 214.

[0068] In some cases, the fuel electrode 214 may be referred to as an anode, and the air electrode 216 may be referred to as a cathode. Alternatively, the fuel electrode 214 may be referred to as a cathode, and the air electrode 216 may be referred to as an anode.

[0069] The first gas diffusion layer 222 and the second gas diffusion layer 224 are configured to uniformly distribute hydrogen and oxygen, which are reactant gases, and transmit the generated electrical energy. To this end, the first gas diffusion layer 222 and the second gas diffusion layer 224 may be disposed on both sides of the membrane electrode assembly 210. That is, the first gas diffusion layer 222 may be disposed on the left side of the fuel electrode 214, and the second gas diffusion layer 224 may be disposed on the right side of the air electrode 216.

[0070] The first gas diffusion layer 222 is configured to diffuse and uniformly distribute hydrogen gas as a reactant gas supplied through the first separator 242 , and may conduct electricity.

[0071] The second gas diffusion layer 224 is configured to diffuse and uniformly distribute air as a reactant gas supplied through the second separator 244 , and may be electrically conductive.

[0072] Each of the first gas diffusion layer 222 and the second gas diffusion layer 224 may be a microporous layer in which fine carbon fibers are mixed. However, exemplary embodiments are not limited to any specific form of the first gas diffusion layer 222 and the second gas diffusion layer 224 .

[0073] The inner gaskets 232, 234, and 236 are each configured to maintain the airtightness and the fastening pressure of the cell stack at an appropriate level with respect to the reactant gas and the coolant, and to disperse the stress when the first separator 242 and the second separator 244 are stacked, and to seal the flow path independently. Therefore, since the airtightness and the watertightness are maintained by the inner gaskets 232, 234, and 236, the flatness of the surface adjacent to the cell stack 122 generating electricity can be ensured, and thus the surface pressure can be evenly distributed on the reaction surface of the cell stack 122.

[0074] The first separator 242 and the second separator 244 may be configured to move reactant gas and cooling medium and to separate each unit cell from other unit cells. In addition, the first separator 242 and the second separator 244 may be configured to structurally support the membrane electrode assembly 210 and the gas diffusion layers 222 and 224, and to collect the generated current and transmit the collected current to the current collectors 112A and 112B.

[0075] The first separator 242 and the second separator 244 may be spaced apart from each other in a first direction (e.g., x-axis direction), and may be respectively disposed outside the first gas diffusion layer 222 and the second gas diffusion layer 224. That is, the first separator 242 may be disposed on the left side of the first gas diffusion layer 222, and the second separator 244 may be disposed on the right side of the second gas diffusion layer 224.

[0076] The first separator 242 is configured to supply hydrogen as a reactant gas to the fuel electrode 214 through the first gas diffusion layer 222. The second separator 244 is configured to supply air as a reactant gas to the air electrode 216 through the second gas diffusion layer 224.

[0077] Furthermore, each of the first separator 242 and the second separator 244 may form a channel through which a cooling medium (eg, coolant) can flow.

[0078] The first end plate 110A and the second end plate 110B may be disposed at both side ends of the battery stack 122 and may support and fix a plurality of unit batteries. That is, the first end plate 110A may be disposed on one of the both side ends of the battery stack 122, and the second end plate 110B may be disposed on the other side of the both side ends of the battery stack 122.

[0079] The current collectors 112A and 112B may be disposed between the battery stack 122 and the inner side surfaces 110AI and 110BI of the first end plate 110A and the second end plate 110B facing the battery stack 122. The current collectors 112A and 112B are configured to collect electrical energy generated by the electron flow in the battery stack 122 and provide the electrical energy to a load of a vehicle using the fuel cell 100. The upper end portions of the current collectors 112A and 112B may be provided with current collecting terminals for transmitting electrical energy to the outside thereof, and the electrical energy may be transmitted through a bus bar and a terminal block via a high-voltage junction box.

[0080] In addition, a bypass plate and an end cell heater may also be disposed between the first end plate 110A and the current collector 112A and between the second end plate 110B and the current collector 112B.

[0081] At least one of the first end plate 110A and the second end plate 110B included in the fuel cell 100 may include a first manifold M1, a second manifold M2, a third manifold M3, a fourth manifold M4, a fifth manifold M5, and a sixth manifold M6. Figure 1A and Figure 1B As shown, the first end plate 110A may include a first manifold M1, a second manifold M2, a fifth manifold M5, and a sixth manifold M6, and the second end plate 110B may include a third manifold M3 and a fourth manifold M4. Alternatively, as will be described below Fig.10 As shown, the second end plate 110B may include a first manifold M1, a second manifold M2, a fifth manifold M5, and a sixth manifold M6, and the first end plate 110A may include a third manifold M3 and a fourth manifold M4. Alternatively, as will be described below Fig.11 As shown, the first end plate 110A may include all of the first manifold M1, the second manifold M2, the third manifold M3, the fourth manifold M4, the fifth manifold M5, and the sixth manifold M6, while the second end plate 110B may not include a manifold. However, the fuel cell 100 according to the exemplary embodiment of the present invention is not limited to any specific configuration structure of the first manifold M1, the second manifold M2, the third manifold M3, the fourth manifold M4, the fifth manifold M5, and the sixth manifold M6.

[0082] The first manifold M1 and the second manifold M2 may be gas inflow manifolds (or gas inlet manifolds) through which reactant gases are introduced from the outside of the fuel cell 100 into the cell stack 122. For example, hydrogen as a reactant gas may be introduced from the outside into the cell stack 122 through one of the first manifold M1 and the second manifold M2, while oxygen as a reactant gas may be introduced from the outside into the cell stack 122 through the other of the first manifold M1 and the second manifold M2.

[0083] One of the third manifold M3 and the fourth manifold M4 may be a cooling medium inlet manifold (or cooling medium inlet manifold), through which the cooling medium is introduced into the fuel cell 100 from the outside to maintain the temperature of the cell stack 122, and the other of the third manifold M3 and the fourth manifold M4 may be a cooling medium outflow manifold (or cooling medium outlet manifold), through which the cooling medium is discharged from the fuel cell 100 to the outside thereof.

[0084] The fifth manifold M5 and the sixth manifold M6 may be gas outflow manifolds (or gas outlet manifolds) through which reactant gas that has been completely used in the cell stack 122 and product water as a byproduct are discharged to the outside of the cell stack 122. For example, hydrogen as a reactant gas may be discharged to the outside of the cell stack 122 together with product water through one of the fifth manifold M5 and the sixth manifold M6, and oxygen as a reactant gas may be discharged to the outside of the cell stack 122 together with product water through the other of the fifth manifold M5 and the sixth manifold M6.

[0085] In this case, the gas outflow manifolds M5 and M6 may be disposed below the gas inflow manifolds M1 and M2.

[0086] Furthermore, the gas inflow manifold and the gas outflow manifold for introducing and exhausting the same reactant gas may be spaced apart from each other in the inclined direction thereof.

[0087] For example, in the case where oxygen as a reactant gas is introduced through the first manifold M1, the oxygen as a reactant gas can be discharged through the sixth manifold M6 spaced apart from the first manifold M1 in the oblique direction. Moreover, in the case where hydrogen as a reactant gas is introduced through the second manifold M2, the hydrogen as a reactant gas can be discharged through the fifth manifold M5 spaced apart from the second manifold M2 in the oblique direction. On the other hand, in the case where hydrogen as a reactant gas is introduced through the first manifold M1, the hydrogen as a reactant gas can be discharged through the sixth manifold M6 spaced apart from the first manifold M1 in the oblique direction. Moreover, in the case where oxygen as a reactant gas is introduced through the second manifold M2, the oxygen as a reactant gas can be discharged through the fifth manifold M5 spaced apart from the second manifold M2 in the oblique direction.

[0088] refer to Figure 1A and Figure 1B The fuel cell 100 according to the exemplary embodiment of the present invention may further include a side cover 150 and an enclosure 140. The side cover 150 may be disposed between the second end plate 110B and the enclosure 140, and may be coupled to the second end plate 110B and the enclosure 140.

[0089] One end and the other end of the housing 140 may be respectively coupled to the first end plate 110A and the side cover 150 to surround the battery stack 122, the current collectors 112A and 112B, and the second end plate 110B. In this manner, the housing 140 and the side cover 150 may be configured as a housing of the fuel cell 100 together with the first end plate 110A.

[0090] Also, the plurality of fasteners 130 are configured to fasten the plurality of unit cells together with the first end plate 110A and the second end plate 110B in a first direction (e.g., the x-axis direction). For example, the plurality of fasteners 130 for fastening the plurality of unit cells may be formed in a bar shape, but the exemplary embodiment is not limited to any specific shape of the plurality of fasteners 130 in the first direction. Therefore, the fastening pressure of the battery stack 122 can be maintained by the end plates 110A and 110B and the fasteners 130 including a rigid body structure.

[0091] Hereinafter, a plurality of fasteners 130 and components connected to the fasteners 130 according to exemplary embodiments will be described with reference to the accompanying drawings.

[0092] Figure 3A FIG. 1 is a diagram showing a plurality of fasteners 130 and a Figure 1B A perspective view of the connection of the cell stack 122 in the fuel cell 100 is shown. Figure 3B It is shown Figure 3A A front view of the battery stack 122 coupled with a plurality of fasteners 130 is shown.

[0093] Figure 4 FIG. 1 is a diagram showing another exemplary embodiment of a plurality of fasteners 130 and Figure 1B A front view of a connection of a cell stack 122 in a fuel cell 100 is shown.

[0094] The plurality of fasteners 130 may include two types of fasteners, ie, first fasteners and second fasteners.

[0095] The first fastener may fasten the plurality of unit cells in the first direction, and may be disposed on at least one edge portion of the battery stack 122 and extend in the first direction. To this end, the first fastener may include an insulating portion disposed at the edge portion of the battery stack 122, extending from the upper portion of the battery stack 122 to the side portion of the battery stack 122 (corresponding to the first insulating portion and the second insulating portion explained below), and a first metal portion disposed at the edge portion of the battery stack 122, the first metal portion being disposed on the insulating portion.

[0096] The second fastener may fasten the plurality of unit batteries in the first direction, and may be disposed on at least one of the upper and lower surfaces of the battery stack 122 and spaced apart from the first fastener and extend in the first direction. To this end, the second fastener may include a third insulating portion disposed on the battery stack 122 and a second metal portion disposed on the third insulating portion.

[0097] refer to Figure 3B and Figure 4 The battery stack 122 may include an upper surface US, a lower surface LS, a first side surface SS1, and a second side surface SS2. The lower surface LS is a surface opposite to the upper surface US in a third direction intersecting both the first direction and the second direction, the first side surface SS1 is a surface located between the upper surface US and the lower surface LS, and the second side surface SS2 is a surface opposite to the first side surface SS1 in the second direction.

[0098] Plurality of fasteners 130 may include a first fastening strip 132 , a second fastening strip 134 , a third fastening strip 136 , a fourth fastening strip 138 , a fifth fastening strip 133 , and a sixth fastening strip 137 .

[0099] The first fastening strip 132 may be disposed on the boundary where the upper surface US and the first side surface SS1 meet each other, the second fastening strip 134 may be disposed on the boundary where the upper surface US and the second side surface SS2 meet each other, the third fastening strip 136 may be disposed on the boundary where the lower surface LS and the first side surface SS1 meet each other, and the fourth fastening strip 138 may be disposed on the boundary where the lower surface LS and the second side surface SS2 meet each other. The fifth fastening strip 133 may be disposed on the upper surface US of the battery stack 122 and may be disposed between the first fastening strip 132 and the second fastening strip 134. The sixth fastening strip 137 may be disposed on the lower surface LS of the battery stack 122 and may be disposed between the third fastening strip 136 and the fourth fastening strip 138.

[0100] According to an exemplary embodiment of the present invention, Figure 1B , Figure 3A and Figure 3B As shown, each of the first fastening strip 132, the second fastening strip 134, the third fastening strip 136 and the fourth fastening strip 138 includes a first insulating portion and a second insulating portion and a first metal portion, and thus may belong to the first fastener, while each of the fifth fastening strip 133 and the sixth fastening strip 137 includes a third insulating portion and a second metal portion, and thus may belong to the second fastener.

[0101] According to another exemplary embodiment of the present invention, Figure 4 As shown, each of the second fastening strip 134 and the third fastening strip 136 includes a first insulating portion, a second insulating portion and a first metal portion, and thus may belong to the first fastener, while each of the first fastening strip 132, the fourth fastening strip 138, the fifth fastening strip 133 and the sixth fastening strip 137 includes a third insulating portion and a second metal portion, and thus may belong to the second fastener.

[0102] According to various exemplary embodiments of the present invention, unlike what is shown in the drawings, each of first fastening strip 132 and fourth fastening strip 138 may belong to a first fastener, and each of second fastening strip 134, third fastening strip 136, fifth fastening strip 133, and sixth fastening strip 137 may belong to a second fastener.

[0103] Hereinafter, each of the first fastening member and the second fastening member according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

[0104] Figure 5A is a perspective view of a first fastener 310 according to an exemplary embodiment of the present invention, Figure 5B yes Figure 5A A front view of the first fastener 310 is shown.

[0105] Figure 5A and Figure 5B The first fastener 310 shown may correspond to Figure 1B , Figure 3A and Figure 3B The exemplary embodiments of each of the first fastening strip 132, the second fastening strip 134, the third fastening strip 136, and the fourth fastening strip 138 shown or Figure 4 Exemplary embodiments of each of second fastening strip 134 and third fastening strip 136 are shown.

[0106] The first fastener 310 may include a first portion P1 and a second portion P2 .

[0107] The first portion P1 is a portion disposed above or below the battery stack 122 and adjacent to an edge portion of the battery stack 122. The second portion P2 is a portion bent from the first portion P1 and disposed at a side portion of the battery stack 122.

[0108] The first portion P1 may include a first metal portion ME1 and a first insulating portion I1.

[0109] The first metal portion ME1 may include a central portion R and peripheral portions H1 and H2. According to an exemplary embodiment of the present invention, the thickness of the central portion R in the third direction may be less than the thickness of each of the peripheral portions H1 and H2 in the third direction. That is, the first metal portion ME1 may include a shape in which the central portion R thereof is recessed. According to another exemplary embodiment of the present invention, unlike what is shown in the drawings, the peripheral portions H1 and H2 and the central portion R may have the same thickness in the third direction.

[0110] The first insulating portion I1 may be disposed between the first metal portion ME1 and the battery stack 122. For example, as shown in the drawings, the first insulating portion I1 may be disposed to cover a portion of the lower surface, the side surface, and the upper surface of the first metal portion ME1. Alternatively, unlike the drawings, the first insulating portion I1 may be disposed to cover only the lower surface of the first metal portion ME1.

[0111] The second portion P2 may include a second insulating portion I2A disposed at a side of the battery stack 122. Figure 1B , Figure 3A and Figure 3B The second fastening strip 134 or the fourth fastening strip 138 shown or Figure 4 When the second fastening strip 134 is shown, the second insulating portion 12A may be disposed on the second side SS2 of the battery stack 122. However, when the first fastener 310 corresponds to Figure 1B , Figure 3A and Figure 3B The first fastening strip 132 or the third fastening strip 136 shown or Figure 4When the third fastening strip 136 is shown, the second insulating portion 12A may be disposed on the first side SS1 of the battery stack 122 .

[0112] According to an exemplary embodiment of the present invention, as shown in the drawings, the first insulating portion I1 and the second insulating portion I2A may be formed integrally with each other. Alternatively, unlike what is shown in the drawings, the first insulating portion I1 and the second insulating portion I2A may be provided separately from each other.

[0113] Figure 6 is a perspective view of a second fastening member 320 according to an exemplary embodiment of the present invention.

[0114] Figure 6 The second fastener 320 shown may correspond to Figure 1B , Figure 3A , Figure 3B and Figure 4 The exemplary embodiment of each of the fifth fastening strip 133 and the sixth fastening strip 137 shown, or Figure 4 Exemplary embodiments of each of first fastening strip 132 and fourth fastening strip 138 are shown.

[0115] The second fastener 320 may include a second metal part ME2 and a third insulating part 13. Each of the first insulating part I1, the second insulating part I2, and the third insulating part I3 may be made of an electrically insulating material (eg, plastic), and each of the first metal part ME1 and the second metal part ME2 may be made of a conductive metal material.

[0116] The third insulating portion 13 may be disposed between the second metal portion ME2 and the battery stack 122. Figure 1B , Figure 3A , Figure 3B and Figure 4 The fifth fastening strip 133 shown or Figure 4 The first fastening strip 132 shown in FIG. 1 is provided, and the third insulating portion 13 may be disposed between the second metal portion ME2 and the upper surface US of the battery stack 122. Alternatively, if the second fastener 320 corresponds to Figure 1B , Figure 3A , Figure 3B and Figure 4 The sixth fastening strip 137 shown or Figure 4 As shown in the fourth fastening strip 138 , the third insulating portion 13 may be disposed between the second metal portion ME2 and the lower surface LS of the battery stack 122 .

[0117] The second metal part ME2 may have the same shape as the first metal part ME1, and the third insulating part I3 may have the same shape as the first insulating part I1. However, example embodiments are not limited thereto.

[0118] Fig. 7A FIG. 1 is a diagram showing another exemplary embodiment of a plurality of fasteners 130 and Figure 1B A perspective view of the connection of the cell stack 122 in the fuel cell 100 is shown. Figure 7B yes Fig. 7A A front view of a battery stack 122 and a plurality of fasteners 130 is shown.

[0119] According to an exemplary embodiment of the present invention, Figure 1A , Figure 3A , Figure 3B and Figure 4 As shown, the second portion P2 may cover only a portion of the side SS1 or the side SS2 of the battery stack 122 .

[0120] That is, if Figure 1A , Figure 3A and Figure 3B As shown, the second portion P2 of the first fastening strip 132 covers the upper portion of the first side SS1 of the battery stack 122, and the second portion P2 of the third fastening strip 136 covers the lower portion of the first side SS1 of the battery stack 122. In this case, as shown, the second portion P2 of the first fastening strip 132 and the second portion P2 of the third fastening strip 136 only cover a portion of the first side SS1 of the battery stack 122 instead of the entire area thereof.

[0121] Moreover, if Figure 1A , 3A 3B , the second portion P2 of the second fastening strip 134 covers the upper portion of the second side SS2 of the battery stack 122, and the second portion P2 of the fourth fastening strip 138 covers the lower portion of the second side SS2 of the battery stack 122. In this case, as shown in the figure, the second portion P2 of the second fastening strip 134 and the second portion P2 of the fourth fastening strip 138 only cover a portion of the second side SS2 of the battery stack 122 instead of the entire area thereof.

[0122] Moreover, if Figure 4 As shown, the second portion P2 of the second fastening strip 134 covers the upper portion of the second side SS2 of the battery stack 122, and the second portion P2 of the third fastening strip 136 covers the lower portion of the first side SS1 of the battery stack 122. In this case, the second portion P2 of the second fastening strip 134 covers only a portion of the second side SS2 of the battery stack 122 instead of the entire area thereof, and the second portion P2 of the third fastening strip 136 covers only a portion of the first side SS1 of the battery stack 122 instead of the entire area thereof.

[0123] Therefore, if Figure 1A , Figure 3A and Figure 3BAs shown, the second insulating portion 12A as the second portion P2 of the first fastening strip 132 and the second insulating portion 12A as the second portion P2 of the third fastening strip 136 can be spaced apart from each other in the third direction, and the second insulating portion 12A as the second portion P2 of the second fastening strip 134 and the second insulating portion 12A as the second portion P2 of the fourth fastening strip 138 can be spaced apart from each other in the third direction.

[0124] In addition, an angle θ between the second portion P2 and the first portion P1 may be less than or equal to 90°.

[0125] According to another exemplary embodiment of the present invention, Fig. 7A and Figure 7B As shown, the entire area of ​​each of the first side surface SS1 and the second side surface SS2 of the battery stack 122 may be covered by the second portion P2 .

[0126] That is, the second insulating portion I2B as the second part P2 of the first fastening strip 132 and the second insulating portion I2B as the second part P2 of the third fastening strip 136 can be formed integrally with each other, and the second insulating portion I2B as the second part P2 of the second fastening strip 134 and the second insulating portion I2B as the second part P2 of the fourth fastening strip 138 can be formed integrally with each other.

[0127] According to an exemplary embodiment of the present invention, the second portion P2 of the first fastener may have a pattern PT (hereinafter referred to as a "shock absorbing pattern") for protecting the battery stack 122 from external impact. For example, the shock absorbing pattern may have a zig-zag shape, such as Figure 3A As shown, or can have a grid shape, such as Fig. 7A However, example embodiments are not limited to any particular shape of the shock absorbing pattern.

[0128] Figure 8 is along Figure 1A A cross-sectional view taken along line II' in the illustrated exemplary embodiment.

[0129] The fuel cell 100 according to the exemplary embodiment of the present invention may further include a coupling portion. Figure 1A , Figure 1B and Figure 2 The illustration of the connecting part is omitted.

[0130] The coupling portion is configured to couple the first and second fasteners 310 and 320 to the first and second end plates 110A and 110B, and to couple the second end plate 110B to the side cover 150 .

[0131] According to another exemplary embodiment of the present invention, although not shown in the drawings, the coupling portion may couple the housing 140 to the first end plate 110A and the side cover 150 .

[0132] According to an exemplary embodiment of the present invention, the coupling portion may include a first coupling portion, a second coupling portion, and a third coupling portion.

[0133] The first coupling portion couples the first end plate 110A to one end of the fastener, and the second coupling portion couples the second end plate 110B to the other end of the fastener.

[0134] Each of the first fastening strip 132, the second fastening strip 134, the third fastening strip 136, and the fourth fastening strip 138 as fasteners has the same Figure 8 The fifth fastening strip 133 and the sixth fastening strip 137 shown have the same shape, that is, include one end connected to the first connecting portion and the other end connected to the second connecting portion.

[0135] For example, the first coupling portion may include first and second bolts 162 and 166, and the second coupling portion may include third and fourth bolts 164 and 168. However, exemplary embodiments are not limited thereto.

[0136] The third coupling portion couples the side cover 150 to the second end plate 110B. Figure 8 As shown, the third coupling portion may include a fifth bolt 163. However, exemplary embodiments are not limited thereto.

[0137] Each of the first, second, third, fourth, and fifth bolts 162 , 164 , 166 , 168 , and 163 may be a flange bolt.

[0138] Furthermore, the first coupling portion, the second coupling portion and the third coupling portion may further include a sealing gasket. That is, the first coupling portion, the second coupling portion and the third coupling portion may include a first sealing gasket, a second sealing gasket and a third sealing gasket, respectively.

[0139] The first sealing gasket 170 may be disposed between the inner circumferential surface of the insertion hole OP2 formed to allow each of the first and second bolts 162 and 166 (both of which are flange bolts) to pass through or be inserted therein, and the outer circumferential surface of each of the flange bolts 162 and 166. Figure 8 Similar to the fifth fastening strip 133 and the sixth fastening strip 137 shown, in each of the first fastening strip 132, the second fastening strip 134, the third fastening strip 136 and the fourth fastening strip 138, the first sealing gasket 170 can be disposed between the inner circumferential surface of the insertion hole OP1 and the outer circumferential surface of the flange bolt, and the insertion hole OP1 is formed to allow the flange bolt to pass through or be inserted therein.

[0140] The second sealing gasket 172 may be disposed between the inner peripheral surface of the insertion hole formed to allow each of the third and fourth bolts 164 and 168 (both of which are flange bolts) to pass through or be inserted therein, and the outer peripheral surface of each of the flange bolts 164 and 168. Figure 8 Similar to the fifth fastening strip 133 and the sixth fastening strip 137 shown, in each of the first fastening strip 132, the second fastening strip 134, the third fastening strip 136 and the fourth fastening strip 138, a second sealing gasket 172 can be set between the inner peripheral surface of the insertion hole and the outer peripheral surface of the flange bolt, and the insertion hole is formed to allow the flange bolt to pass through or be inserted therein.

[0141] The third sealing gasket 174 may be disposed between an inner circumferential surface of an insertion hole formed to allow the fifth bolt 163 , which is a flange bolt, to pass through or be inserted therein, and an outer circumferential surface of the flange bolt 163 .

[0142] The first sealing gasket 170, the second sealing gasket 172, and the third sealing gasket 174 may be made of a plastic-based material. However, the exemplary embodiments are not limited to any particular material for the gaskets.

[0143] In addition, the fuel cell according to the exemplary embodiment of the present invention may further include an external gasket 180. The external gasket 180 may be disposed between the first end plate 110A and the case 140 and between the side cover 150 and the case 140.

[0144] Hereinafter, various embodiments of the fuel cell 100 will be described with reference to the drawings.

[0145] Fig. 9 is a cross-sectional view of a fuel cell 100A according to an exemplary embodiment of the present invention, Fig.10 is a cross-sectional view of a fuel cell 100B according to another exemplary embodiment of the present invention, Fig.11 is a cross-sectional view of a fuel cell 100C according to still another exemplary embodiment of the present invention.

[0146] Specifically, Fig. 9 Shown along Figure 1A The cross section of the exemplary embodiment 100A obtained by cutting the fuel cell 100 along the II-II' line shown in FIG. Fig.10 Shown by along Figure 1A A cross section of another exemplary embodiment 100B obtained by cutting the fuel cell 100 along the II-II' line shown in FIG. Fig.11 Shown by along Figure 1A A cross section of yet another exemplary embodiment 100C is shown in FIG. 1 , where the fuel cell 100 is cut along line II-II′.

[0147] and Figure 1A and Figure 1B The same components as those shown are denoted by the same reference numerals, and their repeated description will be omitted. Figures 9 to 11 The illustration of the connecting part is omitted.

[0148] Fig. 9 , Fig.10 and Fig.11 Each of the illustrated fuel cells 100A, 100B, and 100C includes first and second end plates 110A and 110B, current collectors 112A and 112B, a cell stack 122 , fasteners 134 and 138 , a housing 140 , and side covers 150 .

[0149] The fuel cell 100B and the fuel cell 100C both include the same configuration as the fuel cell 100A and perform the same operation as the fuel cell 100A except for the arrangement of the first manifold M1, the second manifold M2, the third manifold M3, the fourth manifold M4, the fifth manifold M5, and the sixth manifold M6. The differences between these fuel cells are mainly described below. Fig.10 and Fig.11 is along Figure 1A A cross-sectional view of a fuel cell 100B and a fuel cell 100C taken along line II-II' in FIG. Fig.10 and Fig.11 Chinese Fig. 9 Manifold set up as shown in .

[0150] and Fig. 9 The fuel cell 100A shown is different. Fig.10 The fuel cell 100B shown is configured such that the third manifold M3 and the fourth manifold M4 are provided in the first end plate 110A, and the first manifold M1 , the second manifold M2 , the fifth manifold M5 , and the sixth manifold M6 are provided in the second end plate 110B.

[0151] or, Fig.11 The illustrated fuel cell 100C may be configured such that the first manifold M1 , the second manifold M2 , the third manifold M3 , the fourth manifold M4 , the fifth manifold M5 , and the sixth manifold M6 are all provided in the first end plate 110A.

[0152] Regardless of in which of the first and second end plates 110A and 110B the manifold is disposed, the functions of the first manifold M1 , the second manifold M2 , the third manifold M3 , the fourth manifold M4 , the fifth manifold M5 , and the sixth manifold M6 are the same as described above, and thus repeated descriptions thereof will be omitted.

[0153] Hereinafter, a fuel cell according to a comparative example and a fuel cell according to an exemplary embodiment of the present invention will be described with reference to the drawings.

[0154] Fig.12 It is a perspective view of a fuel cell 10A according to a comparative example.

[0155] The fuel cell 10A according to the comparative example includes a first unit cell module 40 and a second unit cell module 50 and a plurality of fastening strips 42, 44, 52 and 54. Each of the first unit cell module 40 and the second unit cell module 50 includes a cell stack 32 or 34, a first end plate 20A or 22A, a second end plate 20B or 22B, and a current collector. The functions performed by the cell stacks 32 and 34, the first end plates 20A and 22A, the second end plates 20B and 22B, and the current collector are respectively similar to those of the embodiment of the present invention. Figure 2 The illustrated battery stack 122 , the first end plate 110A, the second end plate 110B, and the current collectors 112A and 112B are the same, and thus repeated descriptions will be omitted.

[0156] In the case of the fuel cell 10A according to the comparative example, the end plates 20A, 20B, 22A and 22B including the rigid structure and the fastening strips 42, 44, 52 and 54 constrain both side ends of each of the cell stacks 32 and 34 for maintaining the fastening force.

[0157] Furthermore, in order to distribute the reaction gas and the coolant to the first and second unit cell modules 40 and 50, each of the unit cell modules 40 and 50 includes a first manifold M11 or M21, a second manifold M12 or M22, a third manifold M13 or M23, a fourth manifold M14 or M24, a fifth manifold M15 or M25, and a sixth manifold M16 or M26. Since these manifolds are the same as the first manifold M1, the second manifold M2, the third manifold M3, the fourth manifold M4, the fifth manifold M6, and the sixth manifold M6 described above, their repeated description will be omitted.

[0158] The fuel cell 10A according to the comparative example may further include an impact beam 60 disposed at the side of the first and second unit cell modules 40 and 50 stacked in their vertical direction. The impact beam 60 is configured to ensure stability of the fuel cell 10A when a fuel cell vehicle equipped with the fuel cell 10A undergoes a low-speed collision.

[0159] However, since the impact beam 60 is installed at the side of the unit cell module, the fuel cell 10A according to the comparative example has the following problem, that is, its size in the second direction, that is, the horizontal direction, increases. In addition, installing the impact beam 60 complicates the manufacturing process of the fuel cell 10A and increases the manufacturing cost.

[0160] In contrast, according to the exemplary embodiment of the present invention, the fastener, particularly the second portion P2 of the first fastener 310, can function as the impact beam 60. For example, when the fuel cell 100, 100A, 100B, or 100C according to the exemplary embodiment of the present invention is installed in a vehicle, the second portion P2 of the first fastener 310 can function as the impact beam 60 to ensure sufficient stability against external impact, even though the second portion P2 is made of plastic or the like.

[0161] In order to withstand external impact, the second portion P2 of the first fastening member 310 according to the exemplary embodiment of the present invention may include the following conditions.

[0162] Fig.13 It is a graph representing impulse, where the horizontal axis represents time t and the vertical axis represents force F.

[0163] First, assume that the maximum permissible collision speed at which a fuel cell vehicle can travel without damaging the fuel cell is, for example, 32 kph. At this maximum permissible collision speed, an instantaneous collision will generate an impulse equivalent to the product of an acceleration of about 18 g and a time interval of 80 ms.

[0164] Assuming that the mass of the battery stack is, for example, 30 kgf, the battery stack needs to withstand an impulse calculated by the following formula 1.

[0165] [Formula 1]

[0166] I = F × Δt (F = force, t = time)

[0167] Here, F represents force, t represents time, and the impulse is about 2640 J, which corresponds to Fig.13 The size of the shaded area shown in .

[0168] The above impulse is only illustrative, and the actual impulse may be different from the above impulse according to the weight of the fuel cell, the friction coefficient between the battery stack, and the fastening force. According to an exemplary embodiment of the present invention, in order to withstand external impact, the second insulating portion I2 (I2A or I2B) as the second part P2 may include an elastic modulus of 12 GPa at 23°C and an impact strength of 10 kJ / m 2 The above and the length Z1 in the third direction are 2 mm to 3 mm.

[0169] In addition, if Figure 5B As shown, the second portion P2 may have an inclined shape, and its thickness in the second direction gradually decreases in the direction away from the first portion P1. That is, the end of the second insulating portion I2A abutting against the first metal portion ME1 may have a thickness t1 of more than 15 mm in the second direction, and the opposite end of the second insulating portion I2A may have a thickness t2 of more than 4 mm in the second direction.

[0170] According to an exemplary embodiment of the present invention, the second portion P2 satisfying the above conditions can be used to absorb the impulse. Therefore, there is no need to separately install a fuel cell. Fig.12 An impact beam 60 is shown.

[0171] In general, when an external impact is applied to the battery stack in the second direction, a plurality of unit cells of the battery stack aligned in the first direction may be misaligned and may slide, resulting in a short circuit or gas leakage. According to an exemplary embodiment of the present invention, the second portion P2 of the first fastener 310, rather than the impact beam 60, is disposed on the side of the battery stack 122 to protect the battery stack 122 from external impact. Therefore, compared with Comparative Example 10A, the fuel cell 100, 100A, 100B or 100C according to the exemplary embodiment of the present invention can be reduced in size in the second direction. As a result, the fuel cell according to the exemplary embodiment of the present invention can have a reduced size and an increased output density. In addition, since the second portion P2 of the first fastener 310 is naturally disposed on the side of the battery stack 122 when the first fastener 310 is installed, the impact beam 60 does not need to be installed separately. Therefore, the manufacturing process of the fuel cell according to the exemplary embodiment of the present invention can be simplified, and the manufacturing cost can be reduced compared with Comparative Example 10A.

[0172] In addition, since the second portion P2 of the first fastener 310 according to the exemplary embodiment of the present invention includes a shock absorbing pattern, the weight of the second portion P2 can be reduced. As a result, the weight of the fuel cell 100, 100A, 100B, and 100C can be reduced, and the battery stack 122 can be more effectively protected from external impact while preventing stress concentration.

[0173] because Fig.12 The fastening strips 42, 44, 52 and 54 shown are all made of aluminum alloy, so the parts in contact with the unit cells need to be insulated to ensure insulation resistance. To this end, an insulating plate is provided between the fastening strips 42, 44, 52 and 54 and the battery stacks 32, 34. In contrast, according to an exemplary embodiment of the present invention, in order to ensure insulation performance, the fastening strips 132, 134, 136, 138, 133 and 137 can be realized as resin parts manufactured by insert injection molding, or can be manufactured by tightly fitting metal inserts into resin plates. The inserts of the fastening strips can be manufactured by aluminum processing methods such as casting, extrusion or rolling. In addition, the fastening strips 132, 134, 136, 138, 133 and 137 can have lengths X1 and X2, hardness and tap strength suitable for fixing the length of the battery stack 122.

[0174] The battery stack 122 has a compression / tension reaction force of 2 to 5 tonf. In order to withstand this reaction force, the diameters of the first bolt 162, the second bolt 164, the third bolt 166 and the fourth bolt 168 can be, for example, 5 mm or more, and the diameters Φ1 and Φ2 of the holes OP1 and OP2 can be 5 mm or more. Figure 5A and Figure 6 In addition, in order to have a tap for fastening the first bolt 162, the second bolt 164, the third bolt 166, and the fourth bolt 168, each of the insertion holes OP1 and OP2 may have a depth d of 9 mm or more. However, the exemplary embodiment is not limited thereto.

[0175] The lengths X1 and X2 of the fastening bars 132 to 138 may vary according to the number of unit batteries included in the battery stack 122 .

[0176] Furthermore, the width and area of ​​each of the first and second metal portions ME1 and ME2 may be determined so that the deformation amount of each of the first and second metal portions ME1 and ME2 under tension is equal to or less than 0.1 mm, and the deformation amount may be determined according to Hooke's law shown in Formula 2 below.

[0177] [Formula 2]

[0178]

[0179] Here, δ represents deformation, P represents load, L represents one of lengths X1 and X2 of the first portion ME1 and the second metal portion ME2 , E represents elastic modulus, and A represents cross-sectional areas in the first direction and the second direction.

[0180] Each of the first, second, and third insulating parts I1 to I3 may have a thickness of 2 mm to 3 mm.

[0181] In addition, in the case of the fuel cell 10A according to the comparative example, the fastening strips 42, 44, 52 and 54 are arranged at the center of the cell stacks 32 and 34. In contrast, in the case of the exemplary embodiments 100, 100A, 100B or 100C, the fastener 130 is arranged not only at the central portion of the cell stack 122 but also at the edge portion thereof. Therefore, compared with the comparative example 10A, the exemplary embodiment of the present invention can uniformly maintain the surface pressure of the plurality of unit cells stacked in the first direction. That is, the position of the surface of the unit cell that reacts to the force that pressurizes the unit cell is adjacent to the load position of the fastening strips 132, 133, 134, 136, 137 and 138 that support the unit cell, so that the deformation of the end plates 110A and 110B can be suppressed, so that the surface pressure of the cell stack 122 can be uniformly distributed.

[0182] Fig.14 is a perspective view of a fuel cell 10B according to another comparative example.

[0183] Fig.14 The fuel cell 10B shown may include a first end plate 20A, a second end plate 20B, and a housing 70. Here, the first end plate 20A and the second end plate 20B are respectively implemented with Figure 2 The illustrated first end plate 110A and the second end plate 110B perform the same functions, and the manifolds M1 , M2 , M5 , and M6 perform the same functions as the manifolds M1 , M2 , M5 , and M6 according to the above-described embodiment, respectively.

[0184] The case 70 is configured as a fastener for fastening the plurality of unit cells together with the end plates 20A and 20B in the first direction. That is, the fastening pressure of the battery stack including the plurality of unit cells can be maintained by the end plates 20A and 20B including the rigid body structure and the case 70.

[0185] The housing 70 may include two parts, namely an inverted L-shaped part and an L-shaped part. In this case, when the two parts of the housing 70 and each of the first end plate 20A and the second end plate 20B are connected to each other, there are multiple intersections where the three parts (i.e., the two parts of the housing 70 and the first end plate 20A or the second end plate 20B) intersect with each other, so that the two parts of the housing 70 and the first end plate 20A or the second end plate 20B are fixed to each other. However, at these intersections, watertightness may not be ensured. In addition, there are many bolt fastening points, which complicates the post-processing of the battery stack.

[0186] A method of manufacturing this other comparative example 10B and the fuel cell 100 , 100A, 100B, or 100C according to the exemplary embodiment of the present invention is described below.

[0187] In the case of this other comparative example 10B and the exemplary embodiment of the present invention, a plurality of unit cells are stacked in sequence on one of the first end plate and the second end plate, the other of the first end plate and the second end plate is placed on the last unit cell among the stacked plurality of unit cells, and then an appropriate load is applied to compress the plurality of stacked unit cells.

[0188] Thereafter, in the case of this other comparative example 10B, the battery stack with the clamp fixed thereon is transferred, and then the clamp is released from the battery stack. Thus, the battery stack is inserted into the housing 70 and pressed, and then the end plates 20A and 20B provided at each end of the battery stack are fixed to the housing 70.

[0189] In contrast, in the case of the exemplary embodiment of the present invention, the fastener 130 is fixed to the first and second end plates 110A and 110B provided at each end of the battery stack and pressed. Thereafter, the housing 140 is provided to surround the battery stack 122 and then coupled to the side cover 150 .

[0190] As described above, in the case of this other comparative example 10B, the housing 70 needs to be coupled to the end plates 20A and 20B before the battery stack is compressed. Therefore, after the housing 70 is coupled, in the case where a defective unit cell is detected in the battery stack, it is necessary to perform a disassembly process in the reverse order of the manufacturing process to repair the defective unit cell. That is, the housing 70 needs to be separated from the end plates 20A and 20B. Therefore, it is very difficult to perform the repair process.

[0191] In contrast, in the case of the exemplary embodiment of the present invention, the fasteners 130 are fixed to the end plates 110A and 110B for fastening the battery stack 122 without the aid of the housing 140. Therefore, a defective battery can be detected before the housing 140 is coupled to the side cover 150. That is, according to the exemplary embodiment of the present invention, the manufacturing process of the unit battery stack module and the process of inserting the unit battery stack module into the housing are performed separately. As a result, the process of repairing a defective unit battery is very easy to perform compared to the other comparative example.

[0192] In this manner, according to the exemplary embodiment of the present invention, since the process of inspecting and detecting defective unit cells and the process of inserting the battery stack into the case 140 after manufacturing the battery stack are separately performed, the overall manufacturing and inspecting processes may be simplified.

[0193] In addition, in the case of the exemplary embodiment of the present invention, even if the second portion P2 of the first fastener 310 is Figure 4 As shown, instead of Figure 3B The arrangement shown can also protect the battery stack 122 from external impact, improve the stability of the battery stack 122 in the event of a collision, and improve the durability of the battery stack. Since the second portion P2 as the side of the first fastener 310 includes a shock absorbing pattern, the stability of the battery stack can be more reliably ensured in the event of a low-speed collision.

[0194] In addition, in the case of the exemplary embodiment of the present invention, after the fastener 130 is fixed to the end plates 110A and 110B, the sealing gaskets 170 and 172 are placed around the flange bolts 162, 164, 166 and 168, the housing 140 having a "□" shape is placed to surround the battery stack 122, the side cover 150 is placed to cover the inside of the battery stack 122, and then the third coupling portion (163) is fixed to couple the side cover 150 to the housing 140, thereby achieving a completely waterproof structure. Accordingly, the watertightness and airtightness performance of the battery stack 122 can be improved, and thus its durability can be improved.

[0195] As apparent from the above description, in the fuel cell according to the exemplary embodiment of the present invention, the fastener may be configured not only to provide fastening pressure to the cell stack but also to protect the cell stack from external impact.

[0196] However, the effects that can be achieved by the present invention are not limited to the above-mentioned effects, and those skilled in the art can clearly understand other effects not mentioned herein through the above description.

[0197] The various embodiments described above can be combined with each other without departing from the scope of the present invention unless they are incompatible with each other.

[0198] Furthermore, for any element or process not described in detail in any one of the exemplary embodiments of the present invention, unless otherwise specified, reference may be made to the description of the element or process including the same reference numeral in other exemplary embodiments of the present invention.

[0199] In an exemplary embodiment of the present invention, a vehicle may refer to a concept based on various means of transport. In some cases, a vehicle may be interpreted as being based on a concept that includes not only various land transports such as cars, motorcycles, trucks, and buses that travel on roads, but also various means of transport such as airplanes, drones, and ships.

[0200] To facilitate interpretation and accurately define the appended claims, the terms "upper", "lower", "inner", "outer", "upward", "downward", "upward", "downward", "front", "rear", "back", "inner", "outer", "inward", "outward", "interior", "exterior", "inside", "outside", "forward", "rearward" are used to describe features of the exemplary embodiments with reference to the positions of such features shown in the figures. It will also be understood that the term "connect" or its derivatives refer to both direct and indirect connections.

[0201] The term "and / or" may include a combination of a plurality of related listed items or any one of a plurality of related listed items. For example, "A and / or B" includes all three situations, such as "A", "B" and "A and B".

[0202] In this specification, unless otherwise stated, a singular expression includes a plural expression unless the context clearly states otherwise.

[0203] In an exemplary embodiment of the present invention, “at least one of A and B” may refer to “at least one of A or B” or “at least one of a combination of at least one of A and B”. Furthermore, “one or more of A and B” may refer to “one or more of A or B” or “one or more of a combination of one or more of A and B”.

[0204] In exemplary embodiments of the present invention, it should be understood that terms such as “including” or “having” are intended to refer to the presence of features, numbers, steps, operations, elements, parts, or combinations thereof described in the specification, and do not exclude the possibility of adding or existing one or more other features, numbers, steps, operations, elements, parts, or combinations thereof.

[0205] According to the exemplary embodiments of the present invention, components may be combined with each other to be implemented as a whole, and some components may be omitted.

[0206] For the purpose of explanation and illustration, descriptions of specific exemplary embodiments of the present invention are given above. They are not intended to be exhaustive or to limit the present invention to the exact form disclosed, and it is obvious that many modifications and variations can be made according to the teachings above. In order to explain certain principles of the present invention and its practical application, some exemplary embodiments are selected and described to enable those skilled in the art to make and use various exemplary embodiments of the present invention, as well as various substitutions and modifications thereof. The scope of the present invention should be limited by the claims attached hereto and their equivalents.

Claims

1. A fuel cell, include: a battery stack including a plurality of unit batteries stacked in a first direction thereof; A first end plate and a second end plate respectively disposed at two ends of the battery stack; and a plurality of fasteners configured to fasten the plurality of unit batteries in the first direction, the plurality of fasteners being spaced apart from each other in a second direction intersecting the first direction, wherein the plurality of fasteners include: A first fastener provided on an edge portion of the battery stack in such a manner as to extend in the first direction; and a second fastener provided on at least one of an upper portion and a lower portion of the battery stack in a manner extending in the first direction, Wherein, the first fastener comprises: A first portion disposed on the battery stack or below the battery stack and adjacent to the edge portion; and a second portion bent from the first portion to be disposed at a side of the battery stack, wherein the first portion includes: a first metal portion; and a first insulating portion disposed between the first metal portion and the battery stack, and The second portion includes a second insulating portion disposed on the side of the battery stack.

2. The fuel cell according to claim 1, in, The first insulating portion and the second insulating portion are formed integrally with each other.

3. The fuel cell according to claim 1, in, The second fastener comprises: a second metal portion; and A third insulating portion is disposed between the second metal portion and the battery stack.

4. The fuel cell according to claim 1, in, The second portion covers an entire area of ​​the side portion of the battery stack.

5. The fuel cell according to claim 1, in, The second portion also includes a shock absorbing pattern.

6. The fuel cell according to claim 1, in, The second portion covers a portion of the side of the battery stack.

7. The fuel cell according to claim 6, in, The second portion is formed such that the thickness thereof in the second direction decreases as it is farther from the first portion.

8. The fuel cell according to claim 1, in, The battery stack comprises: upper surface; a lower surface opposite to the upper surface in a third direction intersecting both the first direction and the second direction; a first side surface between the upper surface and the lower surface; and a second side surface opposite to the first side surface in the second direction, and Wherein, the plurality of fasteners further include: A first fastening strip, which is arranged on a boundary where the upper surface and the first side surface meet each other; a second fastening strip disposed on a boundary where the upper surface and the second side surface meet each other; a third fastening strip disposed on a boundary where the lower surface and the first side surface meet each other; a fourth fastening strip disposed on a boundary where the lower surface and the second side surface meet each other; a fifth fastening strip disposed on the upper surface; and A sixth fastening strip is disposed on the lower surface.

9. The fuel cell according to claim 8, in, Each of the first fastening strip, the second fastening strip, the third fastening strip and the fourth fastening strip belongs to the first fastening member, and Wherein, each of the fifth fastening strip and the sixth fastening strip belongs to the second fastening member.

10. The fuel cell according to claim 8, in, Each of the first fastening strip and the fourth fastening strip belongs to the first fastening member, and Wherein, each of the second fastening strip, the third fastening strip, the fifth fastening strip and the sixth fastening strip belongs to the second fastening member.

11. The fuel cell according to claim 8, in, Each of the second fastening strip and the third fastening strip belongs to the first fastening member, and Wherein, each of the first fastening strip, the fourth fastening strip, the fifth fastening strip and the sixth fastening strip belongs to the second fastening member.

12. The fuel cell according to claim 8, in, The elastic modulus of the second insulating part at 23°C is 12 GPa, and the impact strength is 10 kJ / m 2 or greater than 10kJ / m 2 , and the length in the third direction is 2 mm to 3 mm, wherein the thickness of the first end portion of the second insulating portion abutting against the first metal portion in the second direction is 15 mm or greater, and Wherein, a thickness of a second end portion of the second insulating portion opposite to the first end portion in the second direction is 4 mm or greater than 4 mm.

13. The fuel cell according to claim 9, in, The second insulating portion of the first fastening strip and the second insulating portion of the third fastening strip are spaced apart from each other in the third direction, and The second insulating portion of the second fastening strip and the second insulating portion of the fourth fastening strip are spaced apart from each other in the third direction.

14. The fuel cell according to claim 9, in, The second insulating portion of the first fastening strip and the second insulating portion of the third fastening strip are formed integrally with each other, and The second insulating portion of the second fastening strip and the second insulating portion of the fourth fastening strip are formed integrally with each other.

15. The fuel cell according to claim 1, further comprising: include: a side cover coupled to the second end plate; and A housing is coupled to the first end plate and the side cover in such a manner as to surround the side portion of the battery stack.

16. The fuel cell according to claim 15, further comprising: include: a first coupling portion configured to couple the first end plate to a first end portion of each fastener; a second coupling portion configured to couple the second end plate to the second end of each fastener; and The third coupling portion is configured to couple the side cover to the second end plate.

17. The fuel cell according to claim 16, in, At least one of the first coupling portion, the second coupling portion and the third coupling portion comprises: Flange bolts; and A sealing gasket is disposed between the flange bolt and a socket formed to allow the flange bolt to pass therethrough or be inserted therein.

18. The fuel cell according to claim 17, in, The diameter of the insertion hole is 5 mm or greater, and the depth of the insertion hole is 9 mm or greater.

19. A fuel cell, include: a battery stack including a plurality of unit batteries stacked in a first direction thereof; A first end plate and a second end plate respectively disposed on a first end and a second end of the battery stack; a side cover coupled to the second end plate; a housing coupled to the first end plate and the side cover in a manner surrounding a side portion of the battery stack; a first fastener configured to fasten the plurality of unit batteries in the first direction and disposed on an edge portion of the battery stack in such a manner as to extend in the first direction; a second fastener configured to fasten the plurality of unit batteries in the first direction, disposed on at least one of an upper portion and a lower portion of the battery stack and spaced apart from the first fastener, and extending in the first direction; and a coupling portion configured to couple each of the first and second fasteners to each of the first and second end plates and to couple the side cover to the housing, wherein the first fastener comprises: an insulating portion provided on the edge portion in such a manner as to extend from a region on an upper portion of the battery stack to a region on a side portion of the battery stack; and A metal portion is provided on a portion of the insulating portion, the metal portion being provided on an upper portion of the battery stack and coupled to the coupling portion.

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