Method for manufacturing bipolar plate

Abstract

Disclosed in the present specification is a method for manufacturing a bipolar plate. The method for manufacturing a bipolar plate comprises a step of heating and pressing a laminate of a metal plate and a plastic plate. According to the manufacturing method disclosed in the present specification, the bipolar plate including the metal plate and the plastic plate attached to each other can be economically manufactured by a relatively simple process. In addition, the bipolar plate manufactured by the manufacturing method is lightweight and can satisfy the conditions required for the bipolar plate.

Description

Method for manufacturing a bipolar plate

[0001] The present application claims the benefit of priority based on Korean patent applications No. 10-2024-0176945, No. 10-2024-0176944 and No. 10-2024-0176943 filed on December 2, 2024, and Korean patent applications No. 10-2025-0151808, No. 10-2025-0151807, No. 10-2025-0151796 and No. 10-2025-0151798 filed on October 20, 2025, all contents of said patent application documents are incorporated herein as part of the specification.

[0002] This specification discloses a method for manufacturing a bipolar plate.

[0003] Electrochemical cells are generally classified into galvanic cells and electrolytic cells. Electrolytic cells can generate hydrogen and oxygen by splitting water using an electric current. These are primarily distinguished by two technical methods: alkaline ion electrolysis and PEM (Proton Exchange Membrane) electrolysis.

[0004] The main part of an engineered electrolytic device is an electrolytic cell having two electrodes and one electrolyte. In a PEM electrolytic cell, the electrolyte contains a proton exchange membrane, and electrodes are located on both sides of the proton exchange membrane. The unit consisting of the electrolyte membrane and the electrodes is called a Membrane Electrode Assembly (MEA).

[0005] In the assembled state of an electrolytic stack composed of multiple electrolytic cells, the electrodes are in contact with so-called bipolar plates through a gas diffusion layer. The bipolar plates separate each electrolytic cell of the stack from one another. The electrolytic cells are separated by an MEA located between them, with the O2 side becoming the positive electrode and the H2 side becoming the negative electrode.

[0006] In a PEM electrolytic cell, sufficiently desalinated water is supplied to the O2 side and decomposes into oxygen gas and protons (H+) at the electrode. The protons pass through the electrolyte membrane and recombine on the H2 side to generate hydrogen gas.

[0007] One important issue in the design of such electrolytic cells is the selection of the material for the bipolar plate.

[0008] High corrosion resistance is required for the bipolar plate under the operating conditions of the electrolytic cell. These operating conditions involve high operating temperatures and high pressure, and under these conditions, the bipolar plate is exposed to conditions where strong reduction occurs on the H2 side and strong oxidation occurs on the O2 side.

[0009] The bipolar plate is in direct contact with the electrolyte membrane on the outer side of the electrode and gas diffusion layer. Considering the surface conditions of the electrolyte membrane, high corrosion resistance is required for the bipolar plate in this state.

[0010] To meet these requirements, bipolar plates are typically manufactured from metallic materials such as titanium.

[0011] Therefore, bipolar plates are typically expensive and not suitable for weight reduction.

[0012] Patent Document 1 discloses a bipolar plate manufactured from a metal plate and a synthetic resin frame as a bipolar plate for solving this problem.

[0013] Patent Document 1 states that the bipolar plate can be manufactured by injection molding and that a thermoplastic resin can be used as the synthetic resin. However, Patent Document 1 does not discuss strict performance requirements that must be met by the bipolar plate, such as durability under acidic conditions to which the bipolar plate is exposed during the electrolysis process or durability under high temperature and high pressure conditions, nor does it specifically disclose the manufacturing method of the bipolar plate that must be considered to meet such performance requirements.

[0014] [Prior Art Literature]

[0015] [Patent Literature]

[0016] (Patent Document 1) U.S. Registered Patent No. 9,845,540

[0017] This specification discloses a method for manufacturing a bipolar plate.

[0018] According to the manufacturing method disclosed in this specification, a bipolar plate comprising a metal plate and a plastic plate attached to each other can be economically manufactured through a relatively simple process. Furthermore, the bipolar plate manufactured by the above method is lightweight and can satisfy the requirements for a bipolar plate.

[0019] Among the physical properties mentioned in this specification, those affected by temperature are properties measured at room temperature unless specifically otherwise defined.

[0020] The term room temperature refers to a natural temperature that has not been artificially heated or cooled, for example, any temperature within the range of about 10°C to 30°C. Typically, a temperature of about 23°C or about 25°C is considered room temperature.

[0021] Unless otherwise specifically defined in this specification, the unit of temperature is °C.

[0022] Among the physical properties mentioned in this specification, those affected by pressure are properties measured at atmospheric pressure, unless otherwise specifically defined.

[0023] The term atmospheric pressure refers to natural pressure that is not artificially pressurized or depressurized, typically ranging from about 700 mmHg to 800 mmHg.

[0024] Among the physical properties mentioned in this specification, those affected by humidity are physical properties measured at ambient temperature and pressure at humidity that is not artificially controlled, unless otherwise specifically defined.

[0025] This specification discloses a bipolar plate.

[0026] The above bipolar plate may include a plastic plate and a metal plate.

[0027] The metal plate and the plastic plate may be laminated together. Additionally, the metal plate and the plastic plate may be in contact with each other, and at least in the contact area, they may be attached to each other.

[0028] Figure 1 is one example of the plastic plate.

[0029] As illustrated in FIG. 1, the plastic plate may have a hole region (1000H) and a frame region (1000F) surrounding the hole region (1000H). The plastic plate may be formed in a frame shape, and the hole region may be formed by the frame shape. This hole region may be a region on which a metal plate is seated.

[0030] As illustrated in FIG. 2, the bipolar plate may have a structure in which the metal plate (1000) is attached to the hole area of ​​the plastic plate (2000). Accordingly, in the bipolar plate, the metal plate (1000) may be attached to the plastic plate (2000) while being located in the hole area (1000H) of the plastic plate (2000). For example, as described later, the metal plate may be attached to the plastic plate while in contact with the seating surface of the plastic plate. As illustrated in FIG. 3, the metal plate may include a convexly raised portion in the center when viewed from the side. The convexly raised portion may be inserted into the hole area (1000H) of the plastic plate, and the edge of the metal plate may be attached to the inner side of the frame area (1000F) of the plastic plate (2000) or to the seating surface described later.

[0031] As exemplarily shown in FIG. 1, one or more selected from the group consisting of a hole (1002) and a flow path (1001) may be formed in the frame region (1000F) of the plastic plate. In one example, both the hole (1002) and the flow path (1001) may be formed in the frame region (1000F). The hole (1002) may be formed to move fluid in a direction parallel to the normal of the surface of the metal plate while attached to the metal plate, and the flow path (1001) may be formed to move fluid in a direction perpendicular to the normal of the surface of the metal plate while attached to the metal plate.

[0032] As used in this specification, vertical and parallel refer to vertical and parallel in a substantial sense, respectively, including cases where they are perfectly vertical and parallel as well as cases where they are approximately vertical and parallel. For example, cases where the angle between them is within the range of approximately 90 ± 5 degrees are included in the vertical, and cases where the angle between them is within the range of approximately ± 5 degrees are included in the horizontal.

[0033] The above fluid may be, for example, oxygen gas and / or hydrogen gas.

[0034] The shape of the hole (1002) and the flow path (1001) is not particularly limited. That is, the hole (1002) and the flow path (1001) can be designed in the necessary shape depending on the application in which the bipolar plate is applied.

[0035] In FIG. 2, a case is illustrated in which one plastic plate (2000) and one metal plate (1000) are attached to each other to form the bipolar plate, but there may be two or more of the plastic plate and / or metal plate.

[0036] For example, the bipolar plate may include two plastic plates, and the two plastic plates may each be attached to both sides of a metal plate.

[0037] As described above, in the bipolar plate, the metal plate may be attached to the plastic plate while being located in the hole area.

[0038] In order to effectively perform attachment with such a metal plate, the plastic plate may have a seating surface.

[0039] In such cases, the metal plate may come into contact with the mounting surface.

[0040] FIGS. 4 to 6 are exemplary drawings for explaining the above-mentioned mounting surface.

[0041] FIG. 4 is a front view of a bipolar plate including a metal plate (1000) and a plastic plate (2000) located in the hole area, and FIG. 5 and 6 are cross-sectional views of the bipolar plate of FIG. 4 cut in the direction of the dotted arrow of FIG. 4.

[0042] As shown in FIGS. 5 and 6, a surface (P1) in contact with the metal plate (1000) can be called the mounting surface, which is a surface formed in a direction perpendicular to the surface normal (dotted arrow in FIGS. 5 and 6) of the plastic plate (2000).

[0043] In this structure, the gap (G) between the surface (P2) of the plastic plate (2000) opposite to the seating surface (P1) and the surface (M2) of the metal plate (1000) exposed in the hole area in the direction opposite to the seating surface (P1) L The standard deviation of ) can be maintained below a certain level.

[0044] In the above bipolar plate, the gap G L When measured at multiple points, the intervals can be maintained uniformly.

[0045] There are no particular restrictions on the selection of the plurality of points mentioned above, but, for example, they may be 12 areas designated at equal intervals along the inner edge of the frame area of ​​the plastic plate (2000). FIG. 7 illustrates such a selection as an example. In FIG. 7, the interval G L The measurement points are indicated by dotted circles. The 12 circles are designated at equal intervals along the inner edge of the frame area. That is, in FIG. 7, the intervals I1, I2+I3, I4, I5, I6+I7, I8, I9, I10+I11, I12, I13, I14+I15, and I16 are identical.

[0046] The upper limit of the standard deviation of the above interval GL may be approximately 600, 550, 500, 450, 400, 350, 300, 290, or 280, and the lower limit may be approximately 0, 50, 100, 150, 200, or 250. The unit of the above standard deviation is μm. The above standard deviation may be within a range of less than or equal to any upper limit arbitrarily selected from the above listed upper limits; or within a range of greater than or equal to any lower limit arbitrarily selected from the above listed lower limits while simultaneously being less than or equal to any upper limit arbitrarily selected from the above listed upper limits.

[0047] In the above case, the interval G measured at the above 12 points L The lower limit of the average (arithmetic mean) may be approximately 100, 150, 200, 250, 300, 350, 400, 450, or 500, and the upper limit may be approximately 1,500, 1,000, 900, 800, 700, 600, or 550. The unit of the average is μm. The average may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0048] Although not specifically limited, as shown in FIGS. 5 and 6, in the above state, the surface (M2) of the metal plate (1000) exposed in the hole area opposite to the mounting surface (P1) may be present on the inside relative to the surface (P2) of the plastic plate (2000) opposite to the mounting surface (P1). This means that the surface (M2) of the metal plate is inward relative to the surface (P2) of the plastic plate (2000).

[0049] As illustrated in FIG. 5, the surface (M1) of the metal plate (1000) exposed in the hole area in the direction of the mounting surface (P1) may be located on the inside relative to the surface (P1F) of the frame area of ​​the plastic plate (2000) on the mounting surface (P1), or as illustrated in FIG. 6, the surface (M1) of the metal plate (1000) exposed in the hole area in the direction of the mounting surface (P1) may be located on the outside relative to the surface (P1F) of the frame area of ​​the plastic plate (2000) on the mounting surface (P1).

[0050] In the form exemplified in FIG. 5, the gap (G in FIG. 5) between the surface (P1F) of the frame area of ​​the plastic plate (2000) on the side of the mounting surface (P1) and the surface (M1) of the metal plate (1000) exposed in the hole area in the direction of the mounting surface (P1) U The standard deviation of ) can also be controlled to below a certain level. The above interval G U The points for measuring may also be 12 areas designated in the manner exemplified in Figure 7 above.

[0051] The above interval G U The upper limit of the standard deviation may be approximately 300, 250, 200, 150, 100, 80, 60, 40, or 20, and the lower limit may be approximately 0, 5, 10, or 15. The unit of the standard deviation is μm. The standard deviation may be within a range of less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range of greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, while simultaneously being less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0052] In the above case, the interval G measured at the above 12 points LThe lower limit of the average (arithmetic mean) may be approximately 50, 100, 150, 200, 220, or 240, and the upper limit may be approximately 600, 550, 500, 450, 400, 350, 300, or 250. The unit of the average is μm. The average may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0053] The bipolar plate exemplified in FIG. 5 can be positioned between bipolar plates when, for example, a plurality of bipolar plates are stacked to form a laminate such as a Membrane Electrode Assembly (MEA). In this case, grooves (glass) configured to move fluid in a direction perpendicular to the normal of the metal plate surface described above may be formed on both sides of the frame area of ​​the plastic plate.

[0054] In the configuration illustrated in FIG. 6, the gap (G in FIG. 6) between the surface (P1F) of the frame region of the plastic plate (2000) on the side of the mounting surface (P1) and the surface (M1) of the metal plate (1000) exposed in the hole region in the direction of the mounting surface (P1) U The standard deviation of ) can also be controlled to below a certain level. The above interval G U The points for measuring may also be 12 regions designated in the manner exemplified in Figure 6 above.

[0055] The above interval G UThe upper limit of the standard deviation may be approximately 400, 350, 300, 250, 200, 150, or 130, and the lower limit may be approximately 0, 50, 100, 110, or 120. The unit of the standard deviation is μm. The standard deviation may be within a range of less than or equal to any upper limit arbitrarily selected from the listed upper limits; or within a range of greater than or equal to any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0056] The interval G measured at the 12 points above L The lower limit of the average (arithmetic mean) may be approximately 30, 50, 100, or 120, and the upper limit may be approximately 600, 550, 500, 450, 400, 350, 300, 250, 200, or 150. The unit of the average is μm. The average may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0057] The bipolar plate exemplified in FIG. 6 can be applied as the outermost bipolar plate when a plurality of bipolar plates are stacked to form a laminate such as a Membrane Electrode Assembly (MEA). In this case, a groove (glass) configured to move fluid in a direction perpendicular to the normal of the metal plate surface described above may be formed on only one of the two sides of the frame area of ​​the plastic plate.

[0058] If a bipolar plate exhibits thickness uniformity as described above, stable and airtight fastening is possible when constructing a laminate, such as a Membrane Electrode Assembly (MEA), using multiple plates. A plate having such uniformity can be manufactured in the manner disclosed herein.

[0059] In the above bipolar plate, the metal plate and the plastic plate may exhibit high bonding strength. For example, the lower limit of the bonding strength may be approximately 15, 20, 25, 30, 35, 40, 45, or 50, and the upper limit may be approximately 100, 95, 90, 85, 80, 75, 70, 65, or 60. The unit of the bonding strength is MPa. The bonding strength may be within a range greater than or exceeding any lower limit arbitrarily selected from the listed lower limits; or within a range greater than or exceeding any lower limit arbitrarily selected from the listed lower limits while simultaneously being less than or less than any upper limit arbitrarily selected from the listed upper limits. The bonding strength may be evaluated in the manner disclosed in the embodiments of this specification. Such high bonding strength can be achieved in accordance with the contents disclosed in this specification.

[0060] The pore characteristics at the bonding interface between the metal plate and the plastic plate of the above-mentioned bipolar plate for the electrolytic device can be controlled.

[0061] For example, pores may not be detected in the XRM analysis of the interface between the metal plate and the plastic plate of the bipolar plate. In another example, if pores are detected in the XRM analysis of the interface between the metal plate and the plastic plate of the bipolar plate, the size of the pores may be controlled. In this state, the corrosion resistance and airtightness required for the bipolar plate, along with the high bonding strength, can be secured.

[0062] For example, if a pore is identified in the above XRM analysis, the size of the pore, specifically the size of the major axis, can be controlled. The major axis refers to the largest dimension among the dimensions of the pore.

[0063] For example, the upper limit of the minimum value of the principal axis distribution (distribution of the principal axis size) of the above pore may be approximately 15 μm, 14 μm, 13 μm, 12 μm, 11 μm, or 10 μm, and the lower limit may be approximately 5 μm, 7 μm, or μm. The minimum value may be within a range of being less than or equal to any upper limit arbitrarily selected from the listed upper limits; or within a range of being greater than or equal to any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0064] The upper limit of the maximum value of the principal axis distribution (distribution of the principal axis size) of the above pores may be approximately 800 μm, 750 μm, 700 μm, 650 μm, 600 μm, 550 μm, or 500 μm, and the lower limit may be approximately 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, or 700 μm. The maximum value may be within a range of less than or equal to any upper limit arbitrarily selected from the listed upper limits; or within a range of greater than or equal to any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0065] The upper limit of the mean of the principal axis distribution of the above pores (distribution of the principal axis size) may be approximately 300 μm, 250 μm, 200 μm, 150 μm, or 120 μm, and the lower limit may be approximately 50 μm, 100 μm, or 150 μm. The mean may be within a range of less than or equal to any upper limit arbitrarily selected from the listed upper limits; or within a range of greater than or equal to any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0066] The upper limit of the median of the principal axis distribution (distribution of the principal axis size) of the above pores may be approximately 300 μm, 250 μm, 200 μm, 150 μm, or 100 μm, and the lower limit may be approximately 50 μm, 100 μm, or 140 μm. The median may be within a range of less than or equal to any upper limit arbitrarily selected from the listed upper limits; or within a range of greater than or equal to any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0067] The upper limit of the standard deviation of the principal axis distribution of the above pores (distribution of the principal axis size) may be approximately 300 μm, 250 μm, 200 μm, 150 μm, 120 μm, 100 μm, or 50 μm, and the lower limit may be approximately 10 μm, 40 μm, 50 μm, or 100 μm. The above standard deviation may be within a range of less than or equal to any upper limit arbitrarily selected from the listed upper limits; or within a range of greater than or equal to any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0068] The distribution of the major axis of the above pores (distribution of the major axis size) can be evaluated in the manner described in Test Example 3 of the present specification.

[0069] In order to secure high bonding strength and / or pore characteristics as described above, the surface shape of the metal plate and / or the manufacturing method of the bipolar plate can be controlled.

[0070] For example, an anchoring shape may exist on the surface of the metal plate, specifically, at least on the surface in contact with the plastic plate. By means of such an anchoring shape, the desired bonding strength and airtightness can be secured more effectively.

[0071] Figure 8 is an example of the side shape of the anchoring shape.

[0072] As shown in FIG. 8, the anchoring shape may be formed with a burr (A1) protruding from the surface of the metal plate that contacts the plastic plate and a groove (A2) that is recessed downward from the surface.

[0073] For example, the lower limit of the height of the anchoring-shaped burr (A1) may be approximately 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90, and the upper limit may be approximately 200, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, or 30. The above height may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, and simultaneously is less than or equal to any upper limit arbitrarily selected from the listed upper limits. The above depth is measured relative to the surface of the metal plate. The unit of the above height is μm.

[0074] For example, the lower limit of the depth of the anchoring shape may be approximately 50, 100, 110, 120, 150, 170, or 190, and the upper limit may be approximately 500, 450, 400, 350, 300, 250, 200, 150, 130, 120, or 110. The depth may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits. The depth is measured relative to the surface of the metal plate. The unit of the depth is μm. Referring to FIG. 8, the depth of the anchoring shape is the sum (A1+A2) of the height (A1) of the burr and the depth (A2) of the groove.

[0075] For example, the lower limit of the width of the anchoring shape (W in FIG. 8) may be approximately 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50, and the upper limit may be approximately 160, 140, 120, 100, 80, 60, 55, or 45. The width may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits. The depth is measured relative to the surface of the metal plate. The unit of the width is μm.

[0076] The lower limit of the pitch of the above anchoring shape pattern may be approximately 50, 100, 150, 155, 160, or 165, and the upper limit may be approximately 500, 450, 400, 350, 300, 250, 200, 170, or 150. The above pitch may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits. The above pitch is the shortest distance between two adjacent anchoring shapes. The unit of the above pitch is μm.

[0077] In cases where the height, depth, and width of the anchoring shape burr (A1) and the pitch of the anchoring shape pattern in the metal plate are not a single constant value, each of the ranges described above is the range of the average value of the corresponding value.

[0078] There are no particular limitations on the method of forming the anchoring shape on the metal plate. For example, the pattern can be formed by scanning the surface of the metal plate with a laser of appropriate output or by physically scratching it.

[0079] When the anchoring shape exists on the surface of the metal plate at the joint portion between the plastic plate and the metal plate, the ratio of the indentation area of ​​the plastic plate to the groove of the anchoring shape may be adjusted. For example, the lower limit of the indentation area ratio may be approximately 40%, 45%, 50%, 55%, 60%, 65%, or 70%, and the upper limit may be approximately 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, or 50%. The indentation area ratio may be within a range greater than or exceeding any lower limit arbitrarily selected from the listed lower limits; or within a range greater than or exceeding any lower limit arbitrarily selected from the listed lower limits while simultaneously being less than or less than any upper limit arbitrarily selected from the listed upper limits.

[0080] The above indentation area ratio can be evaluated in the manner described in Test Example 2 of this specification. By adjusting the ratio to the above range, desired characteristics such as high bonding strength and airtightness can be secured. The above indentation area ratio can be achieved by applying a metal plate having an anchoring shape with the dimensions described above to the manufacturing method of a bipolar plate described later.

[0081] There are no special restrictions on the type of plastic plate included in the above bipolar plate, and an appropriate type may be selected and used depending on the purpose. In one example, as the plastic plate, for instance, a plate containing a polymer may be used.

[0082] There are no special restrictions on the type of polymer included in the plastic plate. For example, conventional EP (Engineering Plastic) may be used as the polymer. For example, the polymer may be a crystalline polymer or an amorphous polymer. The crystalline polymer refers to a polymer having a melting point when verified in the manner disclosed in the embodiments of this specification. The amorphous polymer refers to a polymer not having a melting point when verified in the manner disclosed in the embodiments of this specification.

[0083] For example, the crystalline polymer may be a polymer having a melting point Tm and a glass transition temperature Tg, and the difference between them Tm-Tg may be within a predetermined range.

[0084] For example, the lower limit of the difference Tm-Tg may be approximately 40°C, 60°C, 80°C, 100°C, 120°C, 140°C, 160°C, 180°C, or 185°C, and the upper limit may be approximately 350°C, 330°C, 310°C, 290°C, 270°C, 250°C, 230°C, 210°C, or 200°C. The difference Tm-Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0085] The lower limit of the melting point Tm of the crystalline polymer may be approximately 100°C, 150°C, 200°C, or 250°C, and the upper limit may be approximately 600°C, 550°C, 500°C, 450°C, 400°C, 350°C, or 300°C. The melting point Tm may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, and simultaneously is less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0086] By applying a crystalline polymer having the above characteristics, the bipolar plate intended for this specification can be effectively provided. In particular, such a polymer can effectively form the intended bipolar plate when applied to an injection molding process.

[0087] Various types of crystalline polymers having the above melting point and glass transition temperature may be used. Examples of applicable crystalline polymers include PPS (Polyphenylene sulfide) or PEEK (polyether ether ketone), but are not limited thereto.

[0088] The lower limit of the glass transition temperature of the amorphous polymer may be approximately 40°C, 60°C, 80°C, 100°C, 120°C, 140°C, 160°C, 180°C, or 185°C, and the upper limit may be approximately 600°C, 550°C, 500°C, 450°C, 400°C, 350°C, 300°C, 280°C, 260°C, 240°C, 220°C, 200°C, or 190°C. The glass transition temperature Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0089] By applying an amorphous polymer having the above characteristics, the bipolar plate intended for this specification can be effectively provided. Although not particularly limited, such an amorphous polymer is advantageous for manufacturing a bipolar plate having the above characteristics through the heating and pressurizing method described below.

[0090] Various types of amorphous polymers having the above glass transition temperature can be used. Examples of applicable amorphous polymers include PSU (Polysulfone), PPSU (Polyphenylsulfone), PESU (polyether sulfone), or PES (polyether sulfone), but are not limited thereto.

[0091] There are no special limitations on the proportion of the polymer within the plastic plate, and it can be adjusted to an appropriate ratio depending on the purpose.

[0092] For example, the lower limit of the weight ratio of the polymer based on the total weight of the plastic plate may be approximately 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95, and the upper limit may be approximately 100, 95, 90, 85, 80, 75, 70, or 65. The ratio may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits. The ratio is the weight ratio of the polymer when the total weight of the plastic plate is 100 weight%, and the unit is weight%.

[0093] The above plastic plate may include a filler as an additional component.

[0094] There are no specific limitations on the examples of fillers. For example, organic fillers or inorganic fillers or organic-inorganic fillers, such as glass fillers, carbon fillers and / or silica fillers, etc., may be used as fillers.

[0095] The shape of the above-mentioned filler is determined according to the purpose and is not subject to any specific restrictions. For example, the above-mentioned filler may be a particulate filler (spherical, angular, irregular, or other shaped particulate filler), a plate-shaped filler, or a fibrous filler.

[0096] When a filler is included, the lower limit of the weight ratio of the filler within the plastic plate may be approximately 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, or 65, and the upper limit may be approximately 200, 150, 100, 90, 80, 70, 60, 50, 40, or 30. The ratio may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits. The weight ratio is the weight ratio of the filler relative to 100 parts by weight of the polymer within the plastic plate, and the unit is parts by weight.

[0097] There is no special limitation on the thickness of the plastic plate. For example, the lower limit of the thickness of the plastic plate may be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.5, 3.0, or 3.5, and the upper limit may be 20.0, 19.0, 18.0, 17.0, 16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, or 2.0. The above thickness may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above. The unit of the thickness is mm.

[0098] The method of forming the uneven shape for forming the hole and / or flow path in the plastic plate is not particularly limited. For example, a plastic plate having the hole and / or flow path can be formed by applying a known plastic molding method such as injection molding, vacuum molding, or press molding.

[0099] For example, a metal plate applied to the bipolar plate may be used as a metal plate applied to the configuration of a conventional bipolar plate. Examples of such metal plates may include titanium and / or alloys containing titanium. For example, a plate made of the above material may be used as the metal plate.

[0100] The metal plate may have an appropriate level of melting point. For example, the lower limit of the melting point of the metal plate may be approximately 1,000°C, 1,200°C, 1,400°C, or 1,600°C, and the upper limit may be approximately 3,000°C, 2,500°C, 2,000°C, 1,800°C, or 1,700°C. The melting point may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0101] The thickness of the metal plate can be adjusted to an appropriate level depending on the purpose. For example, the lower limit of the thickness of the metal plate may be approximately 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0, and the upper limit may be approximately 20.0, 19.5, 19.0, 18.5, 18.0, 17.5, 17.0, 16.5, 16.0, 15.5, 15.0, 14.5, 14.0, 13.5, 13.0, It may be approximately 12.5, 12.0, 11.5, 11.0, 10.5, 10.0, 9.5, 9.0, 8.5, 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, or 2. The thickness may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits. The unit of the thickness is mm.

[0102] When the metal plate includes a convex portion as shown in FIG. 3, the lower limit of the height of the convex portion (T1 in FIG. 3) may be approximately 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or 1.1, and the upper limit may be approximately 10.0, 9.5, 9.0, 8.5, 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2, 1.5, or 1. The height may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, and simultaneously is less than or equal to any upper limit arbitrarily selected from the listed upper limits. The unit of the height is mm.

[0103] In the structure of Fig. 3, the dimension T2 may be the value obtained by subtracting the height (T1) of the convex portion from the thickness of the metal plate.

[0104] The present specification discloses a method for manufacturing the bipolar plate. A desired bipolar plate can be manufactured by the method disclosed in the present specification. The bipolar plate can be manufactured by attaching the metal plate and the plastic plate.

[0105] The above manufacturing method may include a step of heating and pressurizing the laminate of the plastic plate and the metal plate.

[0106] The plastic plate of the above laminate may be a plastic plate having a frame region surrounding the aforementioned hole region. Specific details regarding the plastic plate applied to the above manufacturing method are as described above.

[0107] The type of metal plate applied to the above laminate is also as described above.

[0108] In the above laminate, the metal plate may be located in the hole area of ​​the metal plate. The metal plate and the plastic plate may be in contact with each other. That is, the metal plate may be located in the hole area at the center of the frame area and may be in contact with the inner side of the frame area.

[0109] The anchoring pattern described above may exist on the surface of the metal plate in contact with the plastic plate.

[0110] The above heating can be performed within an appropriate temperature range.

[0111] For example, the heating can be performed simultaneously on both the plastic plate side and the metal plate side of the laminate. In this case, the heating temperature T on the plastic plate side (e.g., the heater temperature on the plastic plate side) P and the heating temperature of the metal plate side (e.g., metal plate side heater temperature) T E The ratio T E / T P It can be adjusted.

[0112] For example, the above ratio TE / T P The lower limit of may be approximately 0.1, 0.3, 0.5, 0.7, 0.9, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, or 1.7, and the upper limit may be approximately 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, or 1.1. The above T E / T P It may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or less than any upper limit arbitrarily selected from the upper limits listed above.

[0113] In one example, heating may proceed in different ways depending on whether the plastic plate comprises a crystalline polymer or an amorphous polymer.

[0114] For example, if the above plastic plate contains a crystalline polymer, the ratio T E / T P The lower limit of may be approximately 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.02, 1.04, 1.06, 1.08, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 1.2, and the upper limit may be approximately 2, 1.8, 1.6, 1.4, 1.2, or 1.1. The above T E / T P It may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or less than any upper limit arbitrarily selected from the upper limits listed above.

[0115] For example, if the above plastic plate contains an amorphous polymer, the ratio T E / T PThe lower limit of may be approximately 0.5, 0.7, 0.9, 1, 1.2, 1.4, 1.6, 1.65, or 1.7, and the upper limit may be approximately 2.5, 2, 1.8, 1.5, or 1.4. The above T E / T P It may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the lower limits listed above, and at the same time is less than or less than any upper limit arbitrarily selected from the upper limits listed above.

[0116] For example, the heating is such that the glass transition temperature Tg of the polymer contained in the plastic plate and the heating temperature T on the metal plate side (e.g., the heater temperature on the metal plate side) E The ratio T E / Tg can be adjusted within a predetermined range.

[0117] For example, the above ratio T E The lower limit of / Tg may be approximately 0.1, 0.3, 0.5, 0.7, 0.9, 1, 1.05, 1.1, 1.15, 1.5, 2, 2.5, or 3, and the upper limit may be approximately 10, 9, 8, 7, 6, 5.5, 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1.45, 1.4, 1.35, 1.3, 1.25, 1.2, or 1.1. The above T E / Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0118] For example, the heating is such that the glass transition temperature Tg of the polymer contained in the plastic plate and the heating temperature on the plastic plate side (e.g., the heater temperature on the plastic plate side) T P The ratio T P / Tg can be adjusted within a predetermined range.

[0119] For example, the above ratio TP The lower limit of / Tg may be approximately 0.1, 0.2, 0.3, 0.4, 0.5, 0.55, 0.6, 0.65, 0.7, 0.74, 0.8, 0.9, 1, 1.5, 2, or 2.5, and the upper limit may be approximately 10, 9, 8, 7, 6, 5.5, 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1.0, 0.9, 0.8, or 0.7. The above T P / Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0120] For example, if the plastic plate comprises a crystalline polymer, the temperature T E The ratio T to the above temperature Tg E The lower limit of / Tg may be approximately 1.0, 1.5, 1.7, 1.9, 2.1, 2.3, 2.5, 2.7, or 3, and the upper limit may be approximately 6, 5.5, 5, 4.5, 4.0, 3.5, or 3.0. The above T E / Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0121] For example, if the plastic plate comprises a crystalline polymer, the temperature T P The ratio T to the above temperature Tg P The lower limit of / Tg may be approximately 1, 1.5, or 2.5, and the upper limit may be approximately 10, 9, 8, 7, 6, 5, 4, or 3. The above T P / Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0122] For example, if the plastic plate comprises an amorphous polymer, the temperature T E The ratio T to the above temperature Tg E The lower limit of / Tg may be approximately 0.1, 0.3, 0.5, 0.6, 0.8, 0.85, 0.9, 0.95, 1, 1.1, or 1.2, and the upper limit may be approximately 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1.3, 1.1, 1, 0.8, or 0.7. The above T E / Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0123] For example, if the plastic plate comprises an amorphous polymer, the temperature T P The ratio T to the above temperature Tg P The lower limit of / Tg may be approximately 0.1, 0.3, 0.5, 0.6, 0.7, 0.9, 1.1, or 1.2, and the upper limit may be approximately 2, 1.8, 1.6, 1.4, 1.3, 1.1, 1, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, or 0.75. The above T P / Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0124] For example, the heating process may be performed such that the glass transition temperature Tg of the plastic plate or the polymer contained therein and the heating temperature T have an appropriate relationship. For example, the lower limit of the ratio T / Tg of the heating temperature T and the glass transition temperature Tg may be approximately 0.2, 0.4, 0.6, 0.8, 1, 1.5, 2, 2.5, or 3, and the upper limit may be approximately 10, 8, 6, 4, 2, 1, or 0.8. The T / Tg may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0125] In the above process, the relationship between the melting point of the metal plate and the heating temperature can also be adjusted. For example, the heating temperature in the above process, or the T P and T E The melting point T of the metal plate relative to the higher temperature Tmax. M The ratio T M The lower limit of / Tmax may be approximately 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8, and the upper limit may be approximately 50, 45, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, or 6. The above T M / Tmax may be within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above, and simultaneously less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0126] The heating above may be performed simultaneously with pressurization or separately. For example, in the above method, heating may be performed first, and then pressurization may be performed by applying a load at a certain point.

[0127] For example, the above method may include a first step of heating the laminate and a second step of applying a load to the joint between the plastic plate and the metal plate of the laminate while maintaining the heated state.

[0128] The above heating can be performed at a temperature that satisfies the aforementioned relationship.

[0129] In cases where the steps are divided and performed as described above, the ratio T1 / T2 of the duration T1 of the first step and the duration T2 of the second step may be adjusted. For example, the lower limit of T1 / T2 may be approximately 0.5, 1, 1.5, 2, or 2.5, and the upper limit may be approximately 10, 9, 8, 7, 6, 5, 4, or 3. The ratio T1 / T2 may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0130] The lower limit of the above time T1 may be approximately 0.5 minutes, 1 minute, 1.5 minutes, 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, or 5 minutes, and the upper limit may be approximately 100 minutes, 80 minutes, 60 minutes, 40 minutes, 20 minutes, 10 minutes, 8 minutes, or 6 minutes. The above T1 may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, and at the same time is less than or less than any upper limit arbitrarily selected from the listed upper limits.

[0131] The degree of the load applied during the above process can be controlled. For example, the lower limit of the load applied in the pressurization step or the second step is 1 mm at the joint between the metal plate and the plastic plate. 2The applied load may be approximately 0.01 kgf, 0.05 kgf, 0.1 kgf, 0.15 kgf, 0.2 kgf, 0.25 kgf, 0.5 kgf, 1 kgf, 1.5 kgf, 2 kgf, 2.5 kgf, 3 kgf, 3.5 kgf, or 4 kgf, and the upper limit may be approximately 20 kgf, 15 kgf, 10 kgf, 8 kgf, 6 kgf, 5 kgf, 1 kgf, 0.8 kgf, 0.6 kgf, 0.4 kgf, or 0.3 kgf. The applied load may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or less than any upper limit arbitrarily selected from the listed upper limits.

[0132] A cooling process can be performed after the above heating and pressurization.

[0133] There are no specific restrictions on how this cooling process is performed.

[0134] For example, the above cooling process can be performed by natural cooling. This natural cooling performs cooling while maintaining the laminate at room temperature after the heating and pressurization.

[0135] In another example, the cooling may be performed under a constant temperature. For example, when the temperature at the time of cooling is denoted as Tc and the heating temperature as T, the cooling may be performed under a controlled state such that the ratio Tc / T is within a predetermined range. The heating temperature T is, T P or the above T EThe lower limit of the ratio Tc / T may be approximately 0.01, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, or 0.4, and the upper limit may be approximately 0.9, 0.8, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, or 0.2. The Tc / T may be within a range that is greater than or equal to any lower limit arbitrarily selected from the listed lower limits, and simultaneously less than or equal to any upper limit arbitrarily selected from the listed upper limits.

[0136] Cooling at the above temperature Tc may be performed while applying a load to the laminate, or without applying a load.

[0137] When a load is applied during the cooling process, the upper limit of the applied load may be approximately 0.5, 0.4, 0.3, 0.2, 0.1, 0.08, 0.06, 0.04, or 0.03, and the lower limit may be approximately 0, 0.001, 0.005, 0.01, or 0.02. The load may be within a range less than or equal to any upper limit arbitrarily selected from the listed upper limits; or within a range greater than or equal to any lower limit arbitrarily selected from the listed lower limits, while simultaneously being less than or equal to any upper limit arbitrarily selected from the listed upper limits. The unit of the load is kgf / mm² 2 am.

[0138] The cooling time at the above temperature Tc can be appropriately controlled.

[0139] For example, when cooling at the above temperature Tc is performed without applying a load, the lower limit of the cooling time may be approximately 0.1 minutes, 0.5 minutes, 1 minute, 1.5 minutes, or 2 minutes, and the upper limit may be approximately 40 minutes, 20 minutes, 10 minutes, 8 minutes, 6 minutes, 4 minutes, or 3 minutes. The above time may be within a range that is greater than or exceeds any lower limit arbitrarily selected from the listed lower limits, and at the same time is less than or less than any upper limit arbitrarily selected from the listed upper limits.

[0140] For example, when cooling at the above temperature Tc is performed while applying a load, the lower limit of the cooling time may be approximately 0.5 minutes, 1 minute, or 2 minutes, and the upper limit may be approximately 30 minutes, 25 minutes, 20 minutes, 15 minutes, 10 minutes, or 5 minutes. The time may be within a range greater than or exceeding any lower limit arbitrarily selected from the listed lower limits; or within a range greater than or exceeding any lower limit arbitrarily selected from the listed lower limits while simultaneously being less than or less than any upper limit arbitrarily selected from the listed upper limits.

[0141] The desired bipolar plate can be obtained through the process described above.

[0142] This specification also discloses an electrolytic device comprising the bipolar plate. Such an electrolytic device may be manufactured in a known manner with other known parts, as long as it includes the bipolar plate.

[0143] This specification discloses a method for manufacturing a bipolar plate.

[0144] According to the manufacturing method disclosed in this specification, a bipolar plate comprising a metal plate and a plastic plate attached to each other can be economically manufactured through a relatively simple process. Furthermore, the bipolar plate manufactured by the above method is lightweight and can satisfy the requirements for a bipolar plate.

[0145] Figure 1 is an example of a plastic plate of a bipolar plate.

[0146] Figure 2 is an example of the bonding process between a plastic plate and a metal plate for manufacturing a bipolar plate.

[0147] Figure 3 is a drawing for explaining a metal plate.

[0148] Figure 4 is an example of a bipolar plate.

[0149] Figure 5 is an example of a bipolar plate.

[0150] Figure 6 is an example of a bipolar plate.

[0151] Figure 7 is a diagram illustrating the point where the gap is measured on the bipolar plate.

[0152] Figure 8 is a drawing for explaining the anchoring shape.

[0153] Figure 9 is an example of the bonding process between a plastic plate and a metal plate for manufacturing a bipolar plate.

[0154] Figure 10 is an example of a specimen for measuring bonding strength.

[0155] Figure 11 is a photograph of the anchoring shape applied in the embodiment.

[0156] The method for manufacturing the bipolar plate and the like will be specifically explained through the following examples, but the scope of the manufacturing method is not limited by the following examples.

[0157]

[0158] Preparation Example 1. Metal plate surface treatment

[0159] In order to manufacture a bipolar plate by attaching a plastic plate and a metal plate, surface treatment was performed on the metal plate. A titanium plate (melting point: approximately 1,668°C) was used as the metal plate. As shown in FIG. 1, a channel (1001) and a hole (1002) are formed on one side of the plastic plate. The shape of the metal plate to be surface treated is shown in FIG. 3, where the top of FIG. 3 is a front view of the metal plate and the bottom is a side view of the metal plate. As indicated at the bottom of FIG. 3, a convex shape exists in the center of the metal plate. In the front and side views of FIG. 3, the widths W1 and W2 are 60 mm and 50 mm, respectively, and the lengths L1 and L2 are 60 mm and 50 mm, respectively. In the side view at the bottom of FIG. 3, the thicknesses T1 and T2 are 0.9 mm and 1.1 mm, respectively. Surface treatment (non-contact dry treatment) was performed on the edge portion of the metal plate, excluding the convex portion. The above surface treatment was performed using a laser irradiation device (50W Fiber marking machine, K2 Laser) equipped with a fiber source. The laser was irradiated onto the area requiring surface treatment using the laser irradiation device. Laser irradiation was performed by cross-scanning (mesh form) the surface to be treated at a scan rate of approximately 455 mm / sec, and the number of scan repetitions for the same surface was 4. The maximum output of the laser was set to approximately 50 W, and laser energy was applied with a repetition rate of approximately 70 kHz (Pulse mode). Figure 11 is an image of the anchoring shape formed by the above surface treatment. The height of the burr of the anchoring shape was approximately 65 μm, the depth (the sum of the burr height and the groove depth) was approximately 128 μm, the pitch was approximately 148 μm, and the width of the anchoring shape was approximately 42 μm (based on the XZ plane of the center of the unit pattern).

[0160]

[0161] Example 1

[0162] As shown in FIG. 9, a bipolar plate was manufactured by attaching a plastic plate (1000) and a metal plate (2000). When attaching, the surface-treated area of ​​the metal plate (2000) was laminated so that it came into contact with the plastic plate (1000).

[0163] As the plastic plate, a plastic plate manufactured using a material mixed with PSU (Polysulfone) and glass fiber in a weight ratio of approximately 8:2 (PSU:Glass fiber) was used. The PSU was an amorphous plastic with a glass transition temperature of approximately 187°C. The glass transition temperature and melting point were measured using a Differential Scanning Calorimeter (DSC 8000, Perkin Elmer (USA)). During measurement, the temperature range was set from 40°C to 350°C, and the glass transition temperature was measured while observing changes in heat flow using a heating and cooling mode with a heating and cooling rate of 10°C / min. The sample used for measurement was weighed to have a diameter of approximately 2 mm or less and a weight of approximately 10 mg.

[0164] The metal plate of Manufacturing Example 1 was used as the above metal plate.

[0165] Attachment was performed on the above laminate by applying heat and pressure.

[0166] The heating and pressurization described above were performed using a press machine (BG-200 (Modified), Seongshin Hydraulic Machinery) capable of forming a sealed internal space, heating the internal space, pressurizing the laminate while it is heated by adjusting the pressure within the internal space, and also capable of cooling. First, the laminate was placed in the sealed space of the machine (BG-200 (Modified). At this time, the plastic plate of the laminate was positioned on top, and the metal plate was positioned below it.

[0167] In the above state, the laminate was heated (heating process). Heating was performed by simultaneously operating the upper heater located on the plastic plate side of the laminate and the lower heater located on the metal plate side. During heating, the upper heating temperature was set to approximately 140°C, and the lower heating temperature was set to approximately 200°C. Heating was carried out at the set temperatures and performed for approximately 5 minutes. After heating for 5 minutes, a load was applied to the joint between the plastic plate and the metal plate while maintaining the set temperature (load application process). The load was applied for approximately 2 minutes. The load was applied to the joint area per unit area (1 mm²). 2A load of approximately 2.12 kgf was applied per ) and the load was applied for about 2 minutes. After 2 minutes, the load was released, and cooling was performed by maintaining the temperature of the upper and lower heaters at approximately 50°C to 60°C for about 2 minutes (cooling process). When the bipolar plate was visually inspected after the bonding process, the shape of the attachment area (fusion area) was good, and the bonding strength was approximately 24.4 MPa. The bonding strength was evaluated in the following manner. A specimen was manufactured by cutting the attached plastic plate and metal plate, and the cut specimen was cut so as to include the bonding area between the plastic plate and the metal plate. As shown in FIG. 10, the cutting was manufactured such that the area (C) of the plastic plate (100) that is not the bonding surface and the area (A) of the metal plate (200) that is not the bonding surface were offset based on the bonding area (B) of the plastic plate (1000) and the metal plate (2000). The length of the bonding surface (B) (length of B) was approximately 9 mm, and the width (length of the bonding surface (B) in the direction perpendicular to B) was approximately 12.5 mm. In addition, the length of the protruding part (length of C) of the plastic plate (100) that is not the bonding surface was approximately 36 mm, and the length of the protruding part (length of A) of the metal plate (200) that is not the bonding surface was approximately 35 mm. The bonding strength was evaluated for the above specimen.

[0168] The bonding strength was measured at room temperature (approx. 25°C) using a Universal Testing Machine (UTM, Zwick / Roell Z030). As a method for evaluating tensile shear strength, the protruding parts (parts marked A and C) of the metal plate (200) and plastic plate (100) of the specimen as shown in the drawing were fixed to the equipment, and the bonding strength was evaluated while peeling the plastic plate (100) from the metal plate (200). The peeling was performed at a peeling angle of approximately 180 degrees (parallel to the metal-plastic material parts) and a peeling speed of approximately 50 mm / min. That is, the bonding strength was evaluated by pulling the protruding parts (parts marked A and C) of the metal plate (200) and plastic plate (100) of the specimen in a direction parallel to the metal plate (200) and plastic plate (100) at a speed of approximately 50 mm / min.

[0169]

[0170] Example 2.

[0171] Bonding was performed in the same manner as in Example 1, except that the lower heating temperature in the heating process was set to 220°C and the cooling process was changed. The cooling process was performed by natural cooling, in which the laminate (bipolar plate) was removed from the equipment after the load application process and maintained at room temperature. Upon visual inspection after the bonding process, the shape of the bonded area (fusion area) was good, and the bonding strength was approximately 49.6 MPa.

[0172]

[0173] Example 3.

[0174] Bonding was performed in the same manner as in Example 1, except that the lower heating temperature in the heating process was set to 220℃. Upon visual inspection after the above process, the shape of the bonded area (fusion part) was good, and the bonding strength was approximately 51.5 MPa.

[0175]

[0176] Example 4.

[0177] Bonding was performed in the same manner as in Example 1, except that the lower heating temperature in the heating process was set to 220°C and the cooling process was changed. The cooling process was performed by reducing the load after the load application process and maintaining the temperature of the upper and lower heaters at approximately 50°C to 60°C for about 2 minutes. The load was reduced to approximately 0.027 kgf / mm2. Upon visual inspection after the process, the shape of the bonded area (fusion area) was good, and the bonding strength was approximately 47.1 MPa.

[0178]

[0179] Example 5.

[0180] The bonding was performed in the same manner as in Example 4, except that the lower heating temperature in the heating process was set to 240℃. Upon visual inspection after the above process, severe deformation was observed at the bonded area (fusion area), and the bonding strength was approximately 32.8 MPa.

[0181]

[0182] Example 6.

[0183] As a plastic plate, a plastic plate made of PPSU (Polyphenylsulfone) was used. The PPSU was an amorphous plastic with a glass transition temperature of approximately 220°C and no confirmed melting point when verified in the same manner as in Example 1. Bonding was performed in the same manner as in Example 1, except that the bottom heating temperature in the heating process was set to approximately 240°C using the above plastic plate. Upon visual inspection after the process, the shape of the bonded area (fused part) was good, and the bonding strength was approximately 27.4 MPa.

[0184]

[0185] Example 7.

[0186] Bonding was performed in the same manner as in Example 6, except that the lower heating temperature in the heating process was set to approximately 260°C and the lower heating temperature was set to approximately 200°C. When visually observed after the above process, the shape of the bonded area (fusion area) was good, and the bonding strength was approximately 43.3 MPa.

[0187]

[0188] Example 8.

[0189] In the load application process, the applied load is approximately 1.06 kgf / mm 2 Except for the adjustment, the bonding was performed in the same manner as in 7. Upon visual inspection after the above process, the shape of the bonded area (fusion area) was good, and the bonding strength was approximately 47 MPa.

[0190]

[0191] Example 9.

[0192] The bonding was performed in the same manner as in 7, except that the applied load was adjusted to approximately 0.53 kgf / mm2 during the load application process. Upon visual inspection after the above process, the shape of the bonded area (fusion area) was good, and the bonding strength was approximately 43 MPa.

[0193]

[0194] Comparative Example 1.

[0195] As a plastic plate, a plastic plate manufactured using a material mixed with PPS (Polyphenylene sulfide) and glass fiber was used. The mixing ratio was set to a weight ratio of approximately 6:4 (PPS:Glass fiber). The PPS is a crystalline resin with a glass transition temperature (Tg) of approximately 90°C and a melting point (Tm) of approximately 280°C.

[0196] The above plastic plate was used, and the bonding process was performed in the same manner as in Example 1, except that the lower heating temperature in the heating process was set to approximately 265°C and the upper heating temperature was set to approximately 250°C. However, bonding was not achieved in this process.

[0197]

[0198] Comparative Example 2.

[0199] Bonding was performed in the same manner as Comparative Example 1, except that a load of approximately 4.5 kgf was applied per unit area (1 mm2) of the bonding area during the load application process. Although bonding was performed using the above process, bonding between the metal plate and the plastic plate was not achieved through this process.

[0200]

[0201] Comparative Example 3.

[0202] Bonding was performed in the same manner as Comparative Example 1, except that the lower heating temperature in the heating process was set to 275℃ and a load of approximately 1.06 kgf per unit area (1 mm2) was applied in the load application process. Upon visual inspection after the above process, the appearance of the attachment area (fusion part) was good, but bonding was not effectively achieved at the bonding area.

[0203]

[0204] Comparative Example 4.

[0205] The bonding was performed in the same manner as Comparative Example 1, except that the lower heating temperature in the heating process was set to 275℃ and the cooling process was performed as in Example 2. In the case of the above bonding process, the bonding strength (shear tensile strength) was approximately 10.2 MPa.

[0206]

[0207] Comparative Example 5.

[0208] The bonding was performed in the same manner as Comparative Example 1, except that the lower heating temperature in the heating process was set to 275℃ and the load was applied as in Comparative Example 2. In this case, the bonding strength (shear tensile strength) was confirmed to be approximately 11.1 MPa.

[0209]

[0210] Comparative Example 6.

[0211] Bonding was performed in the same manner as Comparative Example 1, except that the lower heating temperature in the heating process was set to approximately 290°C, the applied load in the load application process was adjusted to approximately 1.06 kgf / mm2, and the cooling process was performed as in Comparative Example 4. Upon visual inspection after the above process, severe deformation was observed at the bonding site (fusion site), and bonding was not performed effectively (bonding strength: 9.86 MPa).

[0212]

[0213] Comparative Example 7.

[0214] Bonding was performed in the same manner as in Comparative Example 6, except that cooling was performed as in Comparative Example 1. Upon visual inspection after the above process, severe deformation was observed in the bonded area (fusion area), and the bonding strength was confirmed to be approximately 15.9 MPa.

[0215]

[0216] Comparative Example 8.

[0217] Bonding was performed in the same manner as Comparative Example 1, except that the lower heating temperature in the heating process was adjusted to approximately 290°C. Upon visual inspection after the above process, severe deformation was observed in the bonded area (fusion area), and the bonding strength was approximately 15.1 MPa.

[0218]

[0219] Comparative Example 9.

[0220] As a plastic plate, a plastic plate manufactured using a material in which PPS (Polyphenylene sulfide) and glass fiber were mixed in a weight ratio of approximately 7:3 (PPS:Glass fiber) was used. The glass transition temperature (Tg) and melting point of the PPS are as described in Comparative Example 1. Bonding was performed in the same manner as in Comparative Example 1, except that the above plastic plate was used, the lower heating temperature during the heating process was set to approximately 275°C, and the cooling process was carried out as in Comparative Example 4. Upon visual inspection after the above process, a crack was observed at the bonding site (fusion site), and the bonding strength was approximately 8.11 MPa, indicating that the bonding was not effectively achieved.

[0221]

[0222] Test Example 1. Plastic Indentation Retention Ratio

[0223] The indentation retention rate of the plastic was verified using images captured with a 3D Profiler Microscope (Motic, PA53MET) (Capturing conditions: x5 magnification, 3D slope mode).

[0224] First, the surface treatment area of ​​the metal plate (metal plate before attaching the plastic plate) that has been surface-treated in the above method is photographed to obtain an image (Image 1). Then, the difference in elevation of Image 1 is analyzed using image processing software (ImageJ) to obtain the average value of the depth of the surface-treated anchoring shape.

[0225] A plastic plate of a bipolar plate manufactured using the metal plate that took the above image 1 is forcibly peeled off from the metal plate as a method to evaluate the bonding strength, and an image (image 2) is obtained for the surface treatment area of ​​the exposed metal plate (the same area as the area obtained in the above image 1).

[0226] The height difference of the above image 2 is analyzed using the same image processing software (ImageJ). In the height difference analysis for the above image 2, areas where the height difference is smaller than the average value obtained for the above image 1 are considered as areas where plastic is pressed and are displayed as white areas, and areas at the level of the average value are considered as areas where plastic is not pressed and are displayed as gray.

[0227] After that, the ratio of the area of ​​the white area in Image 2 to the area of ​​the anchoring shape confirmed in Image 1 was converted into a percentage, and this was set as the indentation retention ratio.

[0228] Table 1 below summarizes the press-fit retention ratios for Examples 1, 3, and 8.

[0229] Example 1 Example 3 Example 8 Press-fit retention ratio ≤ 10% 70% 50%

[0230]

[0231] From Table 1 above, it can be seen that even when the same amorphous plastic is applied, a higher and more stable indentation ratio can be secured by adjusting the upper heating temperature and / or the relationship between the heating temperature and the melting point of the metal plate (e.g., TM / Tmax).

Claims

1. Metal plate and It includes a plastic plate having a frame area surrounding a hole area, and A method for manufacturing a bipolar plate in which the metal plate is located in the hole area and is attached to the plastic plate, wherein The method includes the step of heating and pressurizing the laminate of the plastic plate and the metal plate. A method for manufacturing a bipolar plate in which, in the above laminate, the metal plate is located in the hole area of ​​the plastic plate and is in contact with the frame area.

2. A method for manufacturing a bipolar plate according to claim 1, wherein the surface of the metal plate in contact with the plastic plate in the laminate has an anchoring shape formed by a burr protruding from the surface and a groove recessed downward from the surface.

3. A method for manufacturing a bipolar plate according to claim 2, wherein the height of the anchoring-shaped burr is within the range of 5 to 200 μm.

4. A method for manufacturing a bipolar plate according to claim 2 or 3, wherein the depth of the anchoring shape is within the range of 50 to 500 μm.

5. A method for manufacturing a bipolar plate according to any one of claims 2 to 4, wherein the width of the anchoring shape is within the range of 1 to 160 μm.

6. A method for manufacturing a bipolar plate according to any one of claims 2 to 5, wherein the pitch of the anchoring shape pattern is within the range of 50 to 500 μm.

7. A method for manufacturing a bipolar plate comprising an amorphous polymer or a crystalline polymer, wherein the plastic plate in any one of claims 1 to 6.

8. A method for manufacturing a bipolar plate according to any one of claims 1 to 6, wherein the plastic plate comprises an amorphous polymer or a crystalline polymer and further comprises a filler.

9. A method for manufacturing a bipolar plate, wherein, in any one of claims 1 to 8, the metal plate is a titanium plate or a titanium alloy plate.

10. In any one of claims 1 to 9, the heating temperature T on the plastic plate side of the laminate during heating P , heating temperature T on the metal plate side of the above laminate E and a method for manufacturing a bipolar plate in which the glass transition temperature Tg of the plastic plate satisfies the following formulas 1 to 3: [Equation 1] 0.1 ≤ T E / T P ≤ 2.5 [Equation 2] 0.1 ≤ T E / Tg ≤ 10 [Equation 3] 0.1 ≤ T P / Tg ≤ 10.

11. In claim 10, the heating temperature T on the plastic plate side of the laminate during heating P and heating temperature T on the metal plate side of the laminate E High temperature T max Comparison of the melting point T of the metal plate M The ratio T M / T max A method for manufacturing a bipolar plate having a value of 3 or higher.

12. A method for manufacturing a bipolar plate according to any one of claims 1 to 11, comprising a first step of heating a laminate and a second step of applying a load to a joint between a plastic plate and a metal plate of the laminate while maintaining the heated state.

13. A method for manufacturing a bipolar plate according to claim 12, wherein the ratio T1 / T2 of the duration of the first stage T1 and the duration of the second stage T2 is within the range of 0.5 to 10.

14. In Clause 13, the load is 1 mm at the joint area 2 A method for manufacturing a bipolar plate applied at a rate of 0.01 to 20 kg per plate.

15. A method for manufacturing a bipolar plate according to any one of claims 1 to 14, wherein the step of cooling the laminate after heating and pressurizing is additionally performed.

16. A method for manufacturing a bipolar plate according to claim 15, wherein cooling is performed by natural cooling.

17. A method for manufacturing a bipolar plate according to claim 15, wherein cooling is performed at a cooling temperature Tc satisfying the following formula 8: [Equation 8] 0.01 ≤ Tc / T ≤ 0.9 In Equation 8, Tc is the cooling temperature, and T is the heating temperature in the heating process.

18. A method for manufacturing a bipolar plate according to claim 16, wherein cooling is performed while applying a load to the joint portion of the laminate at a cooling temperature Tc satisfying the following Equation 8: [Equation 8] 0.01 ≤ Tc / T ≤ 0.9 In Equation 8, Tc is the cooling temperature, and T is the heating temperature in the heating process.

19. In Clause 18, the load is 1 mm at the joint area 2 Method for manufacturing a bipolar plate with an applied pressure of 0.5 kgf or less.

20. A method for manufacturing a bipolar plate according to claim 18, wherein the load is applied for 0.1 minutes or more.

Images