Separator and separator structure

Abstract

The present invention provides a separator which has a reaction portion formed on at least one surface and is provided with a protrusion portion along an edge of the reaction portion.

Description

Separator plates and separator structures

[0001] The present invention relates to a separator and a separator structure. More specifically, the present invention relates to a separator and a separator structure used in a water electrolysis or fuel cell stack.

[0002]

[0003] Typically, separators are used in fuel cell or water electrolysis stacks, and along with the membrane electrode assembly (MEA) and gas diffusion layer (GDL), they are key components of the stack. In fuel cells, the separator separates the reactant gases (hydrogen, air, and coolant) and supplies them evenly to the membrane electrode assembly, collecting and transmitting the current generated by the electrochemical reaction. In water electrolysis, the separator supplies the reactant (water) and uniformly transmits the applied current, collecting the oxygen and hydrogen generated by the electrochemical reaction.

[0004] In the past, graphite separators or separators made of graphite and composite resin materials were mainly used, but recently, the use of metal separators made of metal materials is rapidly increasing because they can make the stack smaller and reduce manufacturing costs.

[0005] The properties required for a separator are excellent electrical and thermal conductivity, corrosion resistance, and low gas permeability. In the case of metal, it has the advantages of high strength and thermal conductivity, but has the problem of low corrosion resistance and increased contact resistance.

[0006] Meanwhile, in the case of a membrane electrode assembly manufactured with a polymer membrane, the strength is very low compared to a separator manufactured with SUS or nickel-plated steel plate, and when the stack is connected, it is over-compressed and damaged, and when the cell is connected, the alignment of the GDL or porous transport layer (PTL) is disturbed, causing problems with the durability of the stack.

[0007] Therefore, there is an urgent need to develop a separator that can prevent MEA from being over-compressed and damaged during stack manufacturing using a metal separator, or prevent the alignment of GDL and PTL from flowing, and improve the durability of the stack by fixing them.

[0008] As a related prior art, there is Korean Patent No. 10-1173058.

[0009]

[0010] The purpose of the present invention is to provide a separator and a separator structure including the same, which can improve the performance and durability of a stack by preventing a gasket, a membrane electrode assembly, and a gas diffusion layer arranged in the internal space of the separator from being overcompressed when manufacturing a fuel cell or water electrolysis stack using a metal separator.

[0011] The above and other objects of the present invention can all be achieved by the present invention described below.

[0012]

[0013] 1. One aspect of the present invention relates to a separator.

[0014] The above separator has a reaction portion formed on at least one surface, and a protrusion provided along the edge of the reaction portion.

[0015] 2. Another aspect of the present invention relates to a separator structure.

[0016] The above separator structure includes a pair of separator plates having a euro on one surface and a protrusion along an edge; and an insert disposed between the separator plates; wherein the protrusions are fastened to each other to secure the insert.

[0017] 3. In the above two specific examples, the separator may have a flow path on one side or on both sides.

[0018] 4. In the above 2 or 3 specific examples, the protrusion may have an upper protrusion extending upwardly or a lower protrusion extending downwardly along the direction in which the separator plates are stacked.

[0019] 5. In any one of the above embodiments 2 to 4, the upper protrusion may be provided with a protrusion extending from the outer side, and a groove may be formed on the outer side of the lower protrusion.

[0020] 6. In any one of the above embodiments 2 to 5, a protrusion having an inclined surface extending from the outer side of the upper protrusion and a groove having an inclined surface may be formed on the outer side of the lower protrusion.

[0021] 7. In any one of the above 2 to 6 specific examples, the height of the protrusion and groove is determined according to the following equations 1 and 2, a separator structure:

[0022] [Formula 1]

[0023] About 0.2×h0 < h1 < about 0.8×h0

[0024] [Formula 2]

[0025] About 0.2×h0 < h2 < about 0.8×h0

[0026] Here, h0 is the height of the upper or lower protrusion, h1 is the height of the projection of the upper protrusion, and h2 is the depth of the groove of the lower protrusion.

[0027] 8. In any one of the above embodiments 2 to 7, the upper protrusion may be provided with a protrusion having a semicircular cross-section, and the lower protrusion may be formed with a groove having a semicircular cross-section.

[0028] 9. In any one of the specific examples 2 to 8 above, the insert may include a membrane electrode assembly and a gas diffusion layer or porous transport layer provided on both sides of the membrane electrode assembly.

[0029] 10. In any one of the specific examples 2 to 9 above, a gasket may be provided on one side of the protrusion.

[0030] 11. In any one of the specific examples 2 to 10 above, the height of the lower protrusion when the upper protrusion and the lower protrusion are connected can be determined according to the following equation 3.

[0031] [Formula 3]

[0032] About 0.5×H3 ≤ H1 ≤ about 0.9×H3

[0033] Here, H1 is the height of the lower protrusion, and H3 is the thickness of the gas diffusion layer of the insert.

[0034] 12. Another specific example of the present invention relates to a separator structure in which opposing protrusions are fastened to each other.

[0035] The above separator structure comprises a first separator having a first protrusion along an edge;

[0036] A second separator having a second protrusion along the edge and corresponding to the first protrusion; and

[0037] An insert disposed between the first separator plate and the second separator plate;

[0038] The first protrusion and the second protrusion are connected to each other.

[0039] 13. In the above 12 specific examples, a flow path may be provided on one surface of the first separator and the second separator.

[0040] 14. In the above 12 or 13 specific examples, the first protrusion and the second protrusion have a mutually fitting structure so that the first separator and the second separator can be sealed to each other.

[0041] 15. In any one of the specific examples 12 to 14 above, the first separator plate and the first protrusion may be formed integrally, and the second separator plate and the second protrusion may be formed integrally.

[0042] 16. In any one of the specific examples 12 to 15 above, a protrusion extending from the outer side of the first protrusion and a groove formed on the outer side of the second protrusion can be fastened to each other.

[0043] 17. In any one of the specific examples 12 to 16, a protrusion extending from the outer side of the first protrusion and having an inclined surface and a groove formed on the outer side of the second protrusion and having an inclined surface can be fastened to each other.

[0044] 18. In any one of the specific examples 12 to 17 above, a separator structure in which the heights of the protrusions and grooves are determined according to the following equations 4 and 5:

[0045] [Formula 4]

[0046] About 0.2× h0 < h1 < about 0.8× h0

[0047] [Formula 5]

[0048] About 0.2×h0 < h2 < about 0.8 × h0

[0049] Here, h0 is the height of the first protrusion or the second protrusion, h1 is the height of the protrusion of the first protrusion, and h2 is the depth of the groove of the second protrusion.

[0050] 19. In any one of the specific examples 12 to 18, the first protrusion may be provided with a protrusion having a semicircular cross-section, and the second protrusion may be formed with a groove having a semicircular cross-section.

[0051] 20. In any one of the specific examples 12 to 19 above, the insert may include a membrane electrode assembly and a gas diffusion layer or porous transport layer provided on both sides of the membrane electrode assembly.

[0052] 21. In any one of the specific examples 12 to 20 above, a gasket may be provided on one side of the first protrusion and the second protrusion.

[0053] 22. In any one of the specific examples 12 to 21 above, a separation plate structure in which the height of the entire protrusion in a state in which the first protrusion and the second protrusion are fastened is determined according to the following equation 6:

[0054] [Formula 6]

[0055] About 0.5 × H6 ≤ H4 ≤ about 0.9 × H6

[0056] Here, H4 is the height of the first protrusion, and H6 is the thickness of the gas diffusion layer of the insert.

[0057]

[0058] The separator and separator structure according to the present invention can prevent components having lower strength than the metal separator, such as a gasket and a membrane electrode assembly or a porous transport layer, from being over-compressed and broken during cell manufacturing, and can prevent the alignment of the membrane electrode assembly or the porous transport layer inside the separator from being disrupted, thereby reducing the performance and durability of the stack.

[0059] In addition, the separator structure can prevent insert components such as gaskets, membrane electrode assemblies, and porous transport layers from being overcompressed by spacing the separator plates apart and controlling the fastening pressure without having to fuse a separate gasket or stopper member to the separator plates to prevent overcompressing the separator plates.

[0060] The separator structure has a protrusion having a height of about 50% to 90% of the height of the gas diffusion layer or porous transport layer, which has lower strength than the separator, so that the separator not only fixes the membrane electrode assembly and the porous transport layer but also maintains an appropriate fastening pressure to prevent over-compression of the insert member, while effectively reducing the occurrence of excessive contact resistance of the separator, which is a disadvantage of metal separators.

[0061]

[0062] Figure 1a is a cross-sectional view of a separator according to one specific example of the present invention.

[0063] Figure 1b is a cross-sectional view of a separator according to another specific example of the present invention.

[0064] Figure 2 is a cross-sectional view of a separator structure according to one specific example of the present invention.

[0065] Figure 3 is a cross-sectional view showing a state in which a separator structure having a flow path formed on one side is stacked according to one specific example of the present invention.

[0066] FIG. 4 is a cross-sectional view of a separator structure having a flow path on both sides according to another specific example of the present invention.

[0067] FIG. 5 is a partial cross-sectional view showing an upper protrusion and a lower protrusion according to another specific example of the present invention.

[0068] Figure 6 is a partial cross-sectional view showing a protrusion according to another specific example of the present invention.

[0069] Fig. 7 is a partial cross-sectional view showing a semicircular protrusion of a separator structure according to another specific example of the present invention.

[0070] FIG. 8 is a schematic diagram of a stack including a separator structure according to one specific example of the present invention.

[0071] FIG. 9 is a cross-sectional view of a separator structure having opposing protrusions according to another specific example of the present invention.

[0072] Fig. 10 is a cross-sectional view showing a stacked state of a separator structure having opposing protrusions according to another specific example of the present invention.

[0073] Fig. 11 is a partial cross-sectional view showing the first and second protrusions of a separator structure according to another specific example of the present invention.

[0074] Fig. 12 is a partial cross-sectional view showing a protrusion of a separator structure according to another specific example of the present invention.

[0075] FIG. 13 is a partial cross-sectional view showing first and second protrusions having semicircular protrusions according to another specific example of the present invention.

[0076] FIG. 14 is a schematic diagram of a stack including a separator structure according to another specific example of the present invention.

[0077]

[0078] Hereinafter, the present invention will be described in more detail with reference to the attached drawings. However, the drawings are provided solely to aid understanding of the present invention and are not intended to limit the present invention. Furthermore, the shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings are exemplary and the present invention is not limited to the details depicted.

[0079] Throughout the specification, identical reference numerals designate identical components. Furthermore, in describing the present invention, detailed descriptions of related known technologies are omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0080] In the specification, when "includes," "has," and "consists of" are used, other parts may be added unless "only" is used. When a component is expressed in the singular, it includes cases where the plural is included unless there is a special explicit description.

[0081] When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

[0082] In this specification, “a to b” indicating a numerical range is defined as “≥a and ≤b”.

[0083] In this specification, all numerical ranges include the 95% standard error range.

[0084]

[0085] Hereinafter, a separator according to one aspect of the present invention will be described with reference to the drawings.

[0086] FIG. 1a is a cross-sectional view of a separator according to one specific example of the present invention, and FIG. 1b is a cross-sectional view of a separator according to another specific example of the present invention.

[0087] Referring to FIG. 1, a separator (100) according to one specific example of the present invention is provided with a reaction portion (130) and protrusions (110, 120).

[0088] The above reaction section (130) may be formed on at least one surface of the separator (100). For example, the reaction section (130) may include a flow path (130) through which fuel, air, or coolant flows on one surface of the separator (100).

[0089] Referring to FIG. 1A, the protrusions (110, 120) may be provided along the periphery of the reaction unit (130). The protrusions (110, 120) may be provided to protrude at a certain height at the corners of the reaction unit (130), and when the separators (100) are stacked to form a stack, the gap between one separator (100) and an adjacent separator (100) is controlled by the height of the protrusions (110), and the clamping pressure applied by the separator (100) to the membrane electrode assembly is limited, thereby preventing damage to an insert including a membrane electrode assembly (MEA), a gas diffusion layer (GDL), or a porous transport layer (PTL) that is seated inside the separator.

[0090] The above protrusions (110, 120) are provided so that not only can the insert be effectively prevented from being damaged by excessive fastening pressure, but also the membrane electrode assembly can be firmly fixed by being fitted by the structure of the protrusions (112, 120), thereby increasing the electrochemical reaction efficiency and durability of the fuel cell or water electrolysis stack.

[0091] Referring to FIG. 1b, in one specific example, the protrusion (110) may be provided to be bent in the direction of stacking of the separator plates, and in this case, the gap between the separator plates may be adjusted by the height of the protrusion (110), and a separator structure may be formed to support the shape of the unit cell and fix a membrane electrode assembly, etc., to be installed inside.

[0092] A separator according to one specific example of the present invention may be made of metal, and can prevent damage to components having lower strength than the separator, such as a membrane electrode assembly or a gas diffusion layer, which are installed inside, and can fix them to improve the durability of the stack.

[0093] FIG. 2 is a cross-sectional view of a separator structure according to one embodiment of the present invention, FIG. 3 is a cross-sectional view showing a state in which separator structures having a flow path formed on one surface are stacked according to one embodiment of the present invention, FIG. 4 is a cross-sectional view of a separator structure having flow paths formed on both surfaces according to another embodiment of the present invention, FIG. 5 is a partial cross-sectional view showing an upper protrusion and a lower protrusion according to another embodiment of the present invention, FIG. 6 is a partial cross-sectional view showing a protrusion according to another embodiment of the present invention, FIG. 7 is a partial cross-sectional view showing a semicircular protrusion of a separator structure according to another embodiment of the present invention, and FIG. 8 is a schematic diagram of a stack including a separator structure according to one embodiment of the present invention.

[0094] Referring to FIGS. 2 to 8, the separator structure (1000) includes a pair of separator plates (100) and an insert (200).

[0095] The above separator (100) can be used in a fuel cell or a water electrolysis stack.

[0096] The above separator (100) may be made of metal such as aluminum alloy, stainless steel or titanium alloy, and has high strength and corrosion resistance.

[0097] Since the above separator (100) has higher strength than the above insert (200), the insert (200) may be damaged by being strongly compressed during the stack manufacturing process, and a configuration for preventing damage to the insert (200) is required. Conventionally, a method of fusing a gasket or a stopper member to the separator (100) itself is mainly used to prevent damage due to over-compression of the insert (200). However, in the separator (100) according to one specific example of the present invention, the gasket or stopper member is not separately fused to the separator (100).

[0098] The above separator plate (100) not only shortens the manufacturing process and reduces the number of working hours because the gasket and stopper members are not directly fused, but also effectively prevents damage to the insert (200) by the separator plate (100) itself.

[0099] The above separator structure (1000) constitutes a unit cell in a fuel cell or water electrolysis stack, and can separate the unit cells within the stack while simultaneously serving as an electron transfer path between cells.

[0100] In one specific example, the separator (100) may be provided with a flow path (130) on one or both sides.

[0101] The above-mentioned passage (130) can provide a passage (130) for transmitting hydrogen or air, and a passage through which coolant or water generated by an electrochemical reaction can flow.

[0102] Referring to FIG. 3, a flow path (130) is provided on one surface of the separator (100), in which case unit cells can be stacked along the Y-axis direction, and the structure of the unit cells can be supported by protrusions (110, 120).

[0103] In one specific example, a porous transporter (600) may be provided in the space between the unit cells, and the porous transporter (600) is formed as a three-dimensional structure including a plurality of pores, thereby enabling movement of fluid instead of a flow path.

[0104] A membrane electrode assembly (260) may be placed on one side of the porous transporter (600), and when fuel and air are delivered through the porous transporter, they may flow into the membrane electrode assembly (260) and cause a cell chemical reaction and a water electrolysis reaction.

[0105] Referring to FIG. 4, a flow path (130) may be provided on both sides of the separator (100), in which case the flow of fluid introduced into the cell may be increased.

[0106] The above separator (100) is provided with protrusions (110, 120) along the edge.

[0107] The above separator structure (1000) comprises a pair of separator plates (100) to form a unit cell, and each separator plate is provided with a protrusion (110, 120), and the protrusions (110, 120) are fastened to each other to press the insert (200).

[0108] The above protrusions (110, 120) are provided so that the separator plate provides a space in which the insert (200) is placed, and the degree of compression of the insert (200) can be adjusted.

[0109] In one specific example, the protrusions (110, 120) may have an upper protrusion (110) extending upwardly along the direction in which the separator plates are stacked (Y-axis direction) or a lower protrusion (120) extending downwardly. For example, the protrusions (110, 120) may have shapes extending in the upper and lower directions.

[0110] The shapes of the upper protrusion (110) and the lower protrusion (120) may be the same, and a smooth portion may be formed at one end so that the protrusions can be firmly fastened by contacting each other.

[0111] The method for fastening the above-mentioned protrusions (110, 120) is not limited as long as it is a method capable of joining metal separators. For example, it may include a physical bond that introduces a fastening structure into the protrusions and a chemical bond that forms a bead between the protrusions through welding to change the structure of the metal atoms.

[0112] In one specific example, the separator structure (1000) may be used in a water electrolysis cell, and in the case of a water electrolysis cell, a flow path may be provided on both sides so that water, which is a reactant, may act as a coolant. When the flow path (130) is provided on both sides of the separator (100), a cathode and an anode may exist on one separator (100), and in this case, since electrons can move directly through the separator, the effect of reducing the electrical conduction resistance within the separator may be exhibited.

[0113] In one specific example, the upper protrusion (110) may be provided with a protrusion (110a) extending from the outer side, and a groove (120b) may be formed on the outer side of the lower protrusion (120).

[0114] One smooth portion of the above protrusions (110, 120) may further include a fastening structure to increase the fastening force between the opposing protrusions (110, 120).

[0115] Referring to FIGS. 5 and 6, a projection (110a) may be provided on the outer side of one of the upper protrusions (110) of a pair of separating plates (100), and a groove (120b) corresponding to the projection (110a) may be formed on the outer side of the lower protrusion (120).

[0116] The above protrusions (110a) and grooves (120b) correspond to each other, and a separator plate (100) is manufactured with a structure that can be fastened, so that a pair of separator plates (100) can be accurately interlocked with each other and fastened, and an insert (200) can be placed inside to form a unit cell.

[0117] In one specific example, a protrusion (110a) extending from the outer side of the upper protrusion (110) and having an inclined surface (111a) and a groove (120b) having an inclined surface (121b) may be formed on the outer side of the lower protrusion (120).

[0118] When a protrusion (110a) having an inclined surface (111a) and a groove (120b) having an inclined surface (121b) are formed, not only can the stack be manufactured by continuously stacking the separator plates, but also, since the inclined surfaces (111a, 121b) can guide the direction of movement in the process in which the protrusion (110a) and the groove (120b) come into contact with each other, in the stacking process of the separator plates (100) for manufacturing the stack, the stack can be manufactured by easily stacking the separator plate (100) on one of the pair of separator plates (100) without a separate precise measuring jig for stacking the separator plates (100), and the efficiency of the manufacturing process can be improved.

[0119] In one specific example, the height of the protrusion (110a) and the groove (120b) can be determined according to the following equations 1 and 2.

[0120] [Formula 1]

[0121] About 0.2×h0 < h1 < about 0.8×h0

[0122] [Formula 2]

[0123] About 0.2×h0 < h2 < about 0.8×h0

[0124] Here, h0 is the height of the upper or lower protrusion (120), h1 is the height of the protrusion (110a) of the upper protrusion (110), and h2 is the depth of the groove (120b) of the lower protrusion (120).

[0125] Since the height (h0) of the upper or lower protrusions (110, 120) is the same, and the height of the protrusion (110a) of the upper protrusion (110) and the depth of the groove (120b) of the lower protrusion (120) are also the same, the protrusion (110a) can be inserted into the groove (120b) of either separator plate and firmly fixed therein.

[0126] When the depth of the above protrusion (110a) and groove (120b) is adjusted within the above range, the fastening force between the separator plates (100) can be improved, and the inside of the separator plate (100) can be effectively sealed while maintaining the structure of the upper and lower protrusions (110, 120).

[0127] Referring to FIG. 7, in one specific example, the upper protrusion (110) may be provided with a protrusion (112) having a semicircular cross-section, and the lower protrusion (120) may be formed with a groove (122) having a semicircular cross-section.

[0128] A semicircular protrusion (112) is provided on the upper protrusion (110) of one of the above pair of separating plates (100), and a corresponding semicircular groove (122) is formed on the lower protrusion (120), so that the separating plates (100) can be continuously stacked.

[0129] When the above semicircular protrusions (112) and grooves (122) are provided, the connection area between the protrusions (110, 120) increases, allowing the space between the separators (100) to be sealed more effectively.

[0130] The upper and lower protrusions (110, 120) are formed with protrusions (110a, 112) of various shapes and corresponding grooves (120b, 122) to increase the fastening force and are firmly fastened to each other, and can effectively seal the internal space of the separator (100).

[0131] In one specific example, the insert (200) may include a membrane electrode assembly (MEA; 260) and a gas diffusion layer (240) provided on both sides of the membrane electrode assembly.

[0132] Specifically, the membrane electrode assembly (260) is provided with electrodes (210, 230) on both sides of the electrolyte membrane (220), and may include a gas diffusion layer (240; GDL) or a porous transport layer (240; PTL) on both sides of the electrodes (210, 230).

[0133] The above insert (200) may be easily damaged due to over-compression by the separator (100), and its durability may be reduced due to continuous pressurization.

[0134] The above insert (200) can be placed between a pair of separator plates (100) to form a unit cell, and when the separator plates (100) are laminated to form a stack, the protrusions (110, 120) can support the separator plates (100) to maintain the unit cell shape.

[0135] In one specific example, a gasket (300a, 300b) may be provided on one side of the upper and lower protrusions (110, 120).

[0136] Conventional metal separators have a gasket or stopper member that is fused to the separator to prevent the insert (200) from being over-compressed. However, since the gasket also has lower strength than the separator, there is a problem of it being damaged due to over-compressing.

[0137] In one specific example, the gasket (300a, 300b) is not a member that supports the pressure of the separator plate (100), but is provided to seal the space between the separator plates (100). A gasket having a lower strength than a conventional gasket for supporting the separator plate can also be used, thereby effectively reducing the manufacturing cost of the stack.

[0138] The above gaskets (300a, 300b) are provided separately on each of a pair of separator plates (100), and when the separator plates (100) are fastened to each other, they are in close contact with the separator plates (100) to increase the sealing effect inside the separator plates (100).

[0139] The above gasket (300) may be provided as a single body, and may also be arranged along the outer periphery of the protrusion of the separator plate (100). Even when the gasket (300) is provided as a single body, the gasket (300) may be fixed by fitting it into the space formed by the separator plate (100) and the protrusions (110, 120), and another separator plate (100) may be stacked to fix the gasket (300).

[0140] In one specific example, the height of the entire protrusion (110, 120) in which the upper protrusion (110) and the lower protrusion (120) are fastened can be determined according to the following equation 3.

[0141] [Formula 3]

[0142] About 0.5×H3 ≤ H1 ≤ about 0.9×H3

[0143] Here, H1 is the height of the lower protrusion (120), and H3 is the thickness of the gas diffusion layer (240) of the insert (200).

[0144] Referring to Fig. 2, the height of the lower protrusion (120) is a length extending downward along the stacking direction (Y-axis direction) based on the inner surface of the separator (100).

[0145] The degree of compression of the gas diffusion layer (240) by the separator (100) can be controlled depending on the height of the lower protrusion (120).

[0146] The height of the upper protrusion (110) is H2, and H2 can be adjusted within the range of the above formula 3.

[0147] Specifically, when the height of the upper protrusion (110) and the height of the lower protrusion (120) are adjusted to be about 50% to 90% (e.g., 50, 60, 70, 80, or 90%) of the thickness of the gas diffusion layer (240) on one side of the insert (200) according to the above formula 3, the gap of the separator (100) is adjusted to a height lower than the thickness of the original gas diffusion layer (240), and the separator (100) can press the gas diffusion layer (240) to firmly fix the insert (200).

[0148] Depending on the height of the upper and lower protrusions (110, 120) within the above range, the separator (100) can be brought into close contact with the insert (200), and the gas diffusion layer (240) can be fixed by being compressed evenly, thereby preventing excessive increase in contact resistance due to damage to the gas diffusion layer (240) or damage to the membrane electrode assembly (260), thereby implementing the effects of the present invention.

[0149] By adjusting the height of the above protrusions (110, 120), not only the insert (200) including the gas diffusion layer (240) but also the gasket (300a, 300b) provided on one side of the protrusions (110, 120) can be prevented from being deformed due to overcompression, and damage to the insert can be prevented during the unit cell manufacturing and stack lamination processes, and the durability of the stack can be increased.

[0150] Referring to Fig. 8, unit cells including the separator structure (1000) can be vertically stacked to form a stack (2000). The process of fusing a gasket (300) or a stopper member to the separator (100) is eliminated, thereby improving stack manufacturing efficiency, and by controlling the height of the protrusions (110, 120) formed integrally with the separator (100), over-compression of the insert (200) including the membrane electrode assembly can be prevented, thereby improving the electrochemical reaction efficiency and durability of the cell stack.

[0151] The above separator plate (100) is provided with protrusions (110, 120) and is formed to correspond to the corner shape of the insert (200) on the inside so that the insert (200) can be fitted and fixed in the space between the separator plates (100), and the insert (200) can be prevented from being misaligned due to movement or vibration during cell manufacturing or stacking.

[0152] The above separator (100) presses the surface of the insert (200), but the height of the protrusions (110, 120) is adjusted so that the insert (100) is not over-compressed, so that the contact resistance between the separator and the insert (200) can also be reduced.

[0153] The above separator structure (1000) forms a unit cell and is laminated to form a stack (2000) that can be used as a fuel cell or a water electrolysis stack, and can effectively increase the efficiency and durability of a fuel cell or a water electrolysis device including the above separator structure (1000).

[0154] Another specific example of the present invention relates to a separator structure (1000) in which opposing protrusions are fastened to each other.

[0155] FIG. 9 is a cross-sectional view showing a separation plate structure having opposing protrusions according to another embodiment of the present invention, FIG. 10 is a cross-sectional view showing a stacked state of separation plate structures having opposing protrusions according to another embodiment of the present invention, FIG. 11 is a partial cross-sectional view showing first and second protrusions of a separation plate structure according to another embodiment of the present invention, FIG. 12 is a partial cross-sectional view showing protrusions of a separation plate structure according to another embodiment of the present invention, FIG. 13 is a partial cross-sectional view showing first and second protrusions provided with semicircular protrusions according to another embodiment of the present invention, and FIG. 14 is a schematic diagram of a stack including a separation plate structure according to another embodiment of the present invention.

[0156] Referring to FIGS. 9 to 14, the separator structure (1000) includes a first separator (400), a second separator (500), and an insert (200).

[0157] The first separator (400) and the second separator (500) may be provided with a fluid flow path (410, 510) on one surface of the separator (400, 500) having the same structure and made of the same material as the separator (100) described above.

[0158] The above first separator (400) may be provided with a first protrusion (420) along the edge.

[0159] The second separator (500) may be provided with a second protrusion (520) along the edge of the same material as the first separator (400).

[0160] The above first separator plate (400) and the second separator plate (500) can be fastened to each other.

[0161] The first protrusion (420) and the second protrusion (520) are connected to each other to form a space inside between the separator plates (400, 500), and the structural shape of the separator plate structure (1000) can be maintained.

[0162] The above insert (200) is placed between the first separator plate (400) and the second separator plate (500). Specifically, it is inserted into the space between the first and second separator plates (400, 500) formed by the first protrusion (420) and the second protrusion (520) being fastened to each other, and can be fixed by being pressed against the inner surface of the separator plate (400, 500).

[0163] Referring to FIG. 9, in one specific example, the separator structure (1000) forms a unit cell, and the unit cells may be sequentially stacked to form a part of a stack.

[0164] When a separator structure (1000) is manufactured using a first separator (400) and a second separator (500) having opposing protrusions (420, 520), lamination is very easy and the stack can be manufactured very efficiently.

[0165] In one specific example, the first protrusion (420) and the second protrusion (520) may have a mutually fitting structure.

[0166] The above-described fitting structure means that one end of the first protrusion (420) is physically and chemically bonded to one end of the second protrusion (520). For example, the first protrusion (420) and the second protrusion (520) may be physically joined by being fastened to each other, and may include being chemically bonded by heating or welding.

[0167] In one specific example, the fitting structure can seal the first separator (400) and the second separator (500) to each other, and can seal the first separator (400) and the second separator (500) by joining between the first protrusion (420) and the second protrusion (520).

[0168] The first separator plate (400) and the first protrusion (420) may be formed integrally, and the second separator plate (500) and the second protrusion (520) may be formed integrally. Specifically, the first protrusion (410) may be formed by bending one end of the first separator plate (400) and extending toward the second separator plate (500), and the second protrusion (520) may also be formed by bending one end of the second separator plate (500) and extending toward the first separator plate (400).

[0169] The first separator plate (400) and the first protrusion (410), and the second separator plate (500) and the second protrusion (520) are formed integrally, thereby increasing the manufacturing efficiency of the separator plates (400, 500), and effectively reducing the manufacturing cost compared to a conventional configuration in which a gasket or stopper member is fused to the separator plate.

[0170] When the first separator (400) and the second separator (500) are formed with a space inside in the shape of the first protrusion (420) and the second protrusion (520), one end of the insert (200) can be fitted into the separator (400, 500) and fixed in close contact with the inner surface of the separator (400, 500), and the alignment of the insert (200) is not disturbed during the manufacturing of the unit cell and the manufacturing of the stack, so that the electrochemical reaction efficiency of the cell and the durability of the cell can be effectively increased.

[0171] In one specific example, a protrusion (421) extending from the outer side of the first protrusion (420) and a groove (521) formed on the outer side of the second protrusion (520) can be fastened to each other.

[0172] Referring to FIGS. 10 and 11, a protrusion (421) extending from the outer side of the first protrusion (420) is provided, and a groove (521) corresponding to the protrusion (421) is formed on the outer side of the second protrusion (520), so that the protrusion (421) and the groove (521) are connected.

[0173] It has a fastening structure in which the shape of one end of the first protrusion (420) and the second protrusion (520) is changed to increase the fastening force.

[0174] When the above protrusion (421) and groove (521) are fastened, the fastening force between the first protrusion (420) and the second protrusion (520) can be increased.

[0175] In one specific example, a protrusion (421) extending from the outer side of the first protrusion (420) and having an inclined surface (421a) and a groove (521) formed on the outer side of the second protrusion (520) and having an inclined surface (521b) can be fastened to each other.

[0176] When the first protrusion (420) is provided as a protrusion (421) having an inclined surface (421a), and an inclined surface (521b) is formed in the groove (521) of the second protrusion (520), the first separator (400) and the second separator (500) approach each other, and the inclined surface can guide the direction of movement in the process in which the protrusion (421) and the groove (521) come into contact, so that the second separator (500) can be fastened to the first separator (400) without a separate jig requiring accuracy for manufacturing a unit cell, and the efficiency of the unit cell manufacturing and stack manufacturing processes can be improved.

[0177] In one specific example, the height of the protrusion (421) and the groove (521) is determined according to the following equations 4 and 5, the separator structure:

[0178] [Formula 4]

[0179] About 0.2×h0 < h1 < about 0.8×h0

[0180] [Formula 5]

[0181] About 0.2×h0 < h2 < about 0.8×h0

[0182] Here, h0 is the height of the first protrusion (420) or the second protrusion (520), h1 is the height of the protrusion (421) of the first protrusion, and h2 is the depth of the groove (521) of the second protrusion (520).

[0183] The heights of the first protrusion (420) and the second protrusion (520) are the same, and the height of the first protrusion (420) and the depth of the groove of the second protrusion (520) are the same.

[0184] When the height of the above protrusion (421) and the depth of the groove (521) are limited within the above range, the fastening force increases, so that the sealing between the first separator (400) and the second separator (500) can be more effectively performed, and the convenience of manufacturing the first and second protrusions (420, 520) can be secured.

[0185] Referring to FIG. 13, in one specific example, the first protrusion (420) may be provided with a protrusion (423) having a semicircular cross-section, and the second protrusion (520) may be formed with a groove (523) having a semicircular cross-section.

[0186] When a semicircular protrusion (423) is provided on the first protrusion (420) and a corresponding semicircular groove (523) is formed on the second protrusion (520), the sealing effect can be increased by increasing the joining area between the first protrusion (420) and the second protrusion (520), and the ease of the joining process between the first separator (400) and the second separator (500) can be improved.

[0187] In one specific example, the insert (200) may include a membrane electrode assembly (260), a gas diffusion layer (240) or a porous transport layer (240) provided on both sides of the membrane electrode assembly.

[0188] The configuration of the above insert (200) is the same as that of the above-described insert (200).

[0189] In one specific example, a gasket (300) may be provided on one side of the first protrusion (420) and the second protrusion (520).

[0190] For example, it may be provided in the inner direction of the first protrusion (420) or the second protrusion (520), and the gasket is not fused to the first separator (400) or the second separator (500).

[0191] In one specific example, the height of the entire protrusions (420, 520) in a state where the first protrusion (420) and the second protrusion (520) are fastened can be determined according to the following equation 6.

[0192] [Formula 6]

[0193] About 0.5 × H6 ≤ H4 ≤ 0.9 × H6

[0194] Here, H4 is the height of the first protrusion (420), and H6 is the thickness of the gas diffusion layer (240) of the insert (200).

[0195] Referring to FIG. 7, the height of the first protrusion (420) is the length extended from the bent position toward the second separator (500), and the height of the second protrusion (520) is the length extended from the bent position toward the first separator (400).

[0196] According to the above formula 6, the height (H4) of the first protrusion (420) can be adjusted within the above range to have a height of about 50% to 90% (e.g., 50, 60, 70, 80, or 90%) of the thickness of the gas diffusion layer (240) of the insert (200). The height (H5) of the second protrusion (520) can have a height of about 50% to 90% (e.g., 50, 60, 70, 80, or 90%) of the thickness of H6 in the above formula 6.

[0197] When the heights of the first protrusion (420) and the second protrusion (520) are limited according to Equation 6, the first separator (400) and the second separator (500) can firmly fix the insert (200) between the first separator (400) and the second separator (500) without over-compressing the insert (200) and the gasket (300), thereby increasing the electrochemical reaction efficiency of the unit cell and also effectively improving the durability of the unit cell.

[0198] Referring to FIG. 14, the unit cells can be stacked to manufacture a stack (2000), which can be utilized as a fuel cell or a water electrolysis stack, and when a separator structure (1000) is included, not only the manufacturing cost but also the manufacturing efficiency can be improved, and the durability of the fuel cell or water electrolysis stack can be secured.

[0199] The separator structure (1000) according to the present invention can maintain the shape of the separator structure by only forming protrusions (110, 120) at the corners of the metal separator, in order to prevent over-compression of the insert (200) including the membrane electrode assembly, the gas diffusion layer (240), and the porous transport layer (240) due to pressure during stacking of the separator plates, without the process of fusing a separate gasket or stopper member to the separator. Not only can the insert (200) be prevented from being over-compression by adjusting the height of the protrusions (110, 120), but also, since the insert (200) is fitted and fixed in a step structure according to the shape of the protrusions (110, 120), damage and cell defects due to misalignment of the insert (200) during unit cell manufacturing and stack manufacturing can be prevented. In addition, the inner surface of the separator is in close contact with the outer surface of the insert (200) and the height of the protrusions (110, 120) is adjusted to be lower than the thickness of the gas diffusion layer or the porous transport layer of the insert (200), so that the insert (200) comes into contact with the inner surface of the separator and is pressurized, so that the contact resistance in the separator can also be significantly reduced.

[0200]

[0201] The present invention has been described above, focusing on specific embodiments. Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from its essential characteristics. Therefore, the disclosed embodiments should be considered illustrative rather than limiting. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

Claims

1. A separator having a reaction portion formed on at least one side and a protrusion provided along the edge of the reaction portion.

2. A pair of separators having protrusions along the edges; and An insert disposed between the above separators; The above protrusions are connected to each other to fix the insert, Separator structure.

3. A separator structure in the second paragraph, wherein the separator has a flow path on one or both sides.

4. A separator structure in the second paragraph, wherein the protrusion has an upper protrusion extending upward along the direction in which the separator plates are stacked or a lower protrusion extending downward.

5. A separation plate structure in the fourth paragraph, wherein the upper protrusion is provided with a protrusion extending from an outer position, and a groove is formed in the outer position of the lower protrusion.

6. A separation plate structure in which, in the fourth paragraph, a protrusion having an inclined surface extending from the outer side of the upper protrusion and a groove having an inclined surface are formed on the outer side of the lower protrusion.

7. In the 5th or 6th paragraph, the height of the protrusion and groove is determined according to the following equations 1 and 2, the separation plate structure: [Formula 1] About 0.2×h0 < h1 < about 0.8×h0 [Formula 2] About 0.2×h0 < h2 < about 0.8×h0 Here, h0 is the height of the upper or lower protrusion, h1 is the height of the projection of the upper protrusion, and h2 is the depth of the groove of the lower protrusion.

8. A separator structure in the fourth paragraph, wherein the upper protrusion is provided with a protrusion having a semicircular cross-section, and the lower protrusion is formed with a groove having a semicircular cross-section.

9. A separator structure according to the second paragraph, wherein the insert includes a membrane electrode assembly and a gas diffusion layer or a porous transport layer provided on both sides of the membrane electrode assembly.

10. A separator structure in accordance with paragraph 2, wherein a gasket is provided on one side of the protrusion.

11. In the second paragraph, the height of the lower protrusion is determined according to the following equation 3, the separation plate structure: [Formula 3] About 0.5×H3 ≤ H1 ≤ 0.9×H3 Here, H1 is the height of the lower protrusion, and H3 is the thickness of the gas diffusion layer of the insert.

12. A first separator plate having a first protrusion along the edge; A second separator having a second protrusion along the edge and corresponding to the first protrusion; and An insert disposed between the first separator plate and the second separator plate; The first protrusion and the second protrusion are connected to each other, Separator structure.

13. A separator structure in accordance with claim 12, wherein a flow path is provided on one surface of the first separator and the second separator.

14. A separator structure in accordance with claim 12, wherein the first protrusion and the second protrusion have a mutually fitting structure to seal the first separator and the second separator to each other.

15. A separation plate structure in claim 12, wherein the first separation plate and the first protrusion are formed integrally, and the second separation plate and the second protrusion are formed integrally.

16. A separation plate structure in accordance with claim 12, wherein a protrusion extending from the outer side of the first protrusion and a groove formed on the outer side of the second protrusion are connected to each other.

17. A separation plate structure in which, in the 12th paragraph, a protrusion extending from the outer side of the first protrusion and having an inclined surface and a groove formed on the outer side of the second protrusion and having an inclined surface are connected to each other.

18. A separator structure according to claim 16 or claim 17, wherein the height of the protrusion and groove is determined according to the following formulas 4 and 5: [Formula 4] About 0.2×h0 < h1 < about 0.8×h0 [Formula 5] About 0.2×h0 < h2 < about 0.8×h0 Here, h0 is the height of the first protrusion or the second protrusion, h1 is the height of the protrusion of the first protrusion, and h2 is the depth of the groove of the second protrusion.

19. A separator structure in claim 12, wherein the first protrusion is provided with a protrusion having a semicircular cross-section, and the second protrusion is formed with a groove having a semicircular cross-section.

20. A separator structure according to claim 12, wherein the insert comprises a membrane electrode assembly and a gas diffusion layer or a porous transport layer provided on both sides of the membrane electrode assembly.

21. A separator structure in accordance with claim 12, wherein a gasket is provided on one side of the first protrusion and the second protrusion.

22. In the 12th paragraph, the height of the first protrusion is determined according to the following equation 6, the separation plate structure: [Formula 6] About 0.5×H6 ≤ H4 ≤ 0.9×H6 Here, H4 is the height of the first protrusion, and H6 is the thickness of the gas diffusion layer of the insert.

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