Bipolar plate

Abstract

Disclosed in the present specification are a bipolar plate, a manufacturing method therefor, and use thereof. Disclosed in the present specification is a bipolar plate which is economically manufactured by bonding a metal plate and a plastic plate, and is advantageous for weight reduction. The bipolar plate allows the bonding between the metal plate and the plastic plate to be stably maintained even under severe conditions, such as being maintained under acidic conditions or being maintained under high-temperature and high-pressure conditions. Disclosed in the present specification are a method for manufacturing the bipolar plate and use thereof.

Description

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 bipolar plate, a method for manufacturing the same, and uses.

[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 oxygen gas and protons (H₂) are supplied from the electrode.+ It is decomposed into ). The two of the above pass through the electrolyte membrane and recombine on the H2 side to produce 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 resistance. 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, resulting in a negative or positive potential.

[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 bipolar plate, a method for manufacturing the same, and uses thereof.

[0018] The present specification aims to disclose a bipolar plate that is economically manufactured and advantageous for weight reduction by bonding a metal plate and a plastic plate. The bonding between the metal plate and the plastic plate can be stably maintained even under harsh conditions, such as being maintained under acidic conditions or under high temperature and high temperature conditions.

[0019] The present specification aims to disclose a method for manufacturing the bipolar plate and its uses.

[0020] Among the physical properties mentioned in this specification, those affected by temperature are properties measured at room temperature unless specifically otherwise defined.

[0021] 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, for example, about 23°C or about 25°C.

[0022] Unless otherwise specifically defined in this specification, the unit of temperature is °C.

[0023] Among the physical properties mentioned in this specification, those affected by pressure are properties measured at atmospheric pressure, unless otherwise specifically defined.

[0024] The term atmospheric pressure refers to natural pressure that is not artificially pressurized or depressurized, typically ranging from about 700 mmHg to 800 mmHg.

[0025] 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.

[0026] This specification discloses a bipolar plate.

[0027] The above bipolar plate may include a plastic plate and a metal plate.

[0028] 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.

[0029] Figure 1 is one example of the plastic plate.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] The above fluid may be, for example, oxygen gas and / or hydrogen gas.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] As described above, in the bipolar plate, the metal plate may be attached to the plastic plate while being located in the hole area.

[0039] In order to effectively perform attachment with such a metal plate, the plastic plate may have a seating surface.

[0040] In such cases, the metal plate may come into contact with the mounting surface.

[0041] FIGS. 4 to 6 are exemplary drawings for explaining the above-mentioned mounting surface.

[0042] 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.

[0043] 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).

[0044] 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.

[0045] That is, in the above bipolar plate, the gap G L When measured at multiple points, the intervals can be maintained uniformly.

[0046] 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.

[0047] The above interval G LThe upper limit of the standard deviation 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 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.

[0048] 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.

[0049] 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).

[0050] 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).

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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 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.

[0058] 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.

[0059] 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.

[0060] In the above bipolar plate, the bonding between the metal plate and the plastic plate can be maintained stably even under harsh conditions.

[0061] For example, the above bipolar plate is △P of Equation 1 below 96 It can represent durability where the absolute value of is within a certain range.

[0062] [Equation 1]

[0063] △P 96 = 100 × (P0 - P 96 ) / P 96

[0064] P in Equation 1 96 Silver is the bonding strength between the metal plate and the plastic plate of the bipolar plate after being maintained at 130°C and 85% relative humidity for 96 hours, and P0 is the bonding strength between the metal plate and the plastic plate in the bipolar plate before being maintained at 130°C and 85% relative humidity for 96 hours.

[0065] △P in Equation 1 96 The upper limit of the absolute value of may be approximately 100, 90, 80, 70, 60, 50, 40, 35, 30, 20, 15, 10, 9, 8, or 7, and the lower limit may be approximately 0, 2, 4, or 6. The above △P 96The absolute value of may be within a range equal to or less than any upper limit arbitrarily selected from the upper limits listed above; or within a range equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, while simultaneously being less than or less than any upper limit arbitrarily selected from the upper limits listed above. The above △P 96 The unit of is %. The above △P 96 It can be positive or negative, and in one example, it can be positive.

[0066] In addition, the above bipolar plate is △P of Equation 2 below 192 It can represent durability where the absolute value of is within a certain range.

[0067] [Equation 2]

[0068] △P 192 = 100 × (P0 - P 192 ) / P 192

[0069] P in Equation 2 192 is the bonding strength between the metal plate and the plastic plate of the bipolar plate after being maintained at 130°C and 85% relative humidity for 192 hours, and P0 is the bonding strength between the metal plate and the plastic plate in the bipolar plate before being maintained at 130°C and 85% relative humidity for 192 hours.

[0070] △P in Equation 2 192 The upper limit of the absolute value of may be approximately 100, 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, 8, or 6, and the lower limit may be approximately 0, 1, 2, 3, or 4. The above △P 192 The absolute value of may be within a range equal to or less than any upper limit arbitrarily selected from the upper limits listed above; or within a range equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, while simultaneously being less than or less than any upper limit arbitrarily selected from the upper limits listed above. The above △P192 The unit of is %. The above △P 192 It can be positive or negative, and in one example, it can be positive.

[0071] In addition, the above bipolar plate is △P of Equation 3 below 288 It can represent durability where the absolute value of is within a certain range.

[0072] [Equation 3]

[0073] △P 288 = 100 × (P0 - P 288 ) / P 288

[0074] P in Equation 3 288 is the bonding strength between the metal plate and the plastic plate of the bipolar plate after being maintained at 130°C and 85% relative humidity for 288 hours, and P0 is the bonding strength between the metal plate and the plastic plate in the bipolar plate before being maintained at 130°C and 85% relative humidity for 288 hours.

[0075] △P of Equation 3 288 The upper limit of the absolute value of may be approximately 100, 90, 80, 70, 60, 50, 40, 30, 20, 15, or 10, and the lower limit may be approximately 0, 1, 3, 5, 7, or 9. The above △P 288 The absolute value of may be within a range equal to or less than any upper limit arbitrarily selected from the upper limits listed above; or within a range equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, while simultaneously being less than or less than any upper limit arbitrarily selected from the upper limits listed above. The above △P 288 The unit of is %. The above △P 288 It can be positive or negative, and in one example, it can be positive.

[0076] △P of the above Equations 1 to 3 96 , △P 192 and △P 288The measurement method of is summarized in Test Example 1 of this specification. In Equations 1 to 3, P0, P 96 , P 192 and P 288 is a bonding strength having the same unit, for example, the unit of the bonding strength is MPa.

[0077] In Equations 1 to 3, the range of the initial bonding strength P0 may be maintained at an appropriate level or higher. For example, the lower limit of the bonding strength P0 may be approximately 30, 35, 40, or 45, and the upper limit may be approximately 200, 150, 100, 90, 80, 70, 60, 50, or 45, although there is no specific limitation. The unit of the bonding strength P0 is MPa. The P0 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.

[0078] The composition of the plastic plate at the joint between the metal plate and the plastic plate in the above bipolar plate can be stably maintained without deterioration even under harsh conditions.

[0079] For example, the above bipolar plate can exhibit durability such that the absolute value of △C in Equation 4 below is within a predetermined range.

[0080] [Equation 4]

[0081] △C = 100 × (C R - C A ) / C A

[0082] C in Equation 4 A is the carbon content within the plastic plate at the bonding interface between the metal plate and the plastic plate of the bipolar plate maintained for 2,000 hours in an aqueous sulfuric acid solution with a pH of 1, and C RThe carbon content in the plastic plate at the bonding interface between the metal plate and the plastic plate of the bipolar plate before maintaining it for 2,000 hours in an aqueous sulfuric acid solution with a pH of 1.

[0083] The above carbon content can be analyzed using the EDAX (Energy Dispersive X-ray Analysis) method, and the analysis method is summarized in Test Example 2.

[0084] The above content is a content measured according to Test Example 2 above, and may be a carbon content confirmed with the sum of the carbon content (C) and oxygen content (O) confirmed at the measurement point (C+O) set to 100 weight%, or a carbon content confirmed with the sum of the carbon content (C), oxygen content (O) and sulfur content (S) confirmed at the measurement point (C+O+S) set to 100 weight%.

[0085] There are no specific limitations on the specific location at the bonding interface for measuring the above content. For example, if the carbon content within the bonding interface is substantially uniform, the carbon content may be the content measured at any point within the bonding interface. If there is non-uniformity in the carbon content within the bonding interface, the carbon content may be the arithmetic mean of the contents measured at two or more random points within the bonding interface.

[0086] As described below, when the plastic plate includes a filler component in addition to the resin component, the carbon content may be measured at a point where the resin component and the filler are present together at the bonding interface, or at a point where only the resin component is present. For example, the △C may be satisfied at a point where the resin component and the filler are present together and / or at a point where only the resin component is present at the bonding interface.

[0087] For example, the upper limit of the absolute value of the above △C may be approximately 6, 4, 2, 1, or 0.5, and the lower limit may be approximately 0, 0.1, or 0.2. The absolute value of the above △C may be within a range of being less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range of being 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. The unit of the above △C is %. The above △C may be positive or negative, and for example, may be positive.

[0088] In addition, the above bipolar plate can exhibit durability in which the absolute value of △O of Equation 5 below falls within a certain range.

[0089] [Equation 5]

[0090] △O = 100 × (O R - O A ) / O A

[0091] O in Equation 5 A is the oxygen content within the plastic plate at the bonding interface between the metal plate and the plastic plate of the bipolar plate maintained for 2,000 hours in an aqueous sulfuric acid solution with a pH of 1, and O R Silver is the oxygen content in the plastic plate at the interface between the metal plate and the plastic plate of the bipolar plate before maintaining it for 2,000 hours in an aqueous sulfuric acid solution with a pH of 1.

[0092] The above oxygen content can be analyzed through the EDAX (Energy Dispersive X-ray Analysis) method, and the analysis method is summarized in Test Example 2. The above content is a content measured according to the above Test Example 2, and may be an oxygen content confirmed with the sum of the carbon content (C) and oxygen content (O) confirmed at the measurement point (C+O) set to 100 wt%, or an oxygen content confirmed with the sum of the carbon content (C), oxygen content (O), and sulfur content (S) confirmed at the measurement point (C+O+S) set to 100 wt%.

[0093] The specific location at the bonding interface for measuring the above content is as described in Equation 1.

[0094] In addition, if the plastic plate includes a filler component in addition to the resin component, △0 can also be satisfied at the point where the resin component and the filler are present together and / or at the point where only the resin component is present among the bonding interfaces.

[0095] For example, the upper limit of the absolute value of the above △O may be approximately 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5, and the lower limit may be approximately 0, 1, 2, 3, 4, or 5. The absolute value of the above △O 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. The unit of the above △O is %. The above △O may be positive or negative, and for example, may be positive.

[0096] In addition, the above bipolar plate can exhibit durability in which the absolute value of △S of Equation 6 below falls within a certain range.

[0097] [Equation 6]

[0098] △S = 100 × (S R - S A ) / S A

[0099] In Equation 6, S A is the sulfur content in the plastic plate at the bonding interface between the metal plate and the plastic plate of the bipolar plate maintained for 2,000 hours in an aqueous sulfuric acid solution with a pH of 1, and S R The sulfur content in the plastic plate at the interface between the metal plate and the plastic plate of the bipolar plate before maintaining it for 2,000 hours in an aqueous sulfuric acid solution with a pH of 1.

[0100] The above sulfur content can be analyzed using the EDAX (Energy Dispersive X-ray Analysis) method, and the analysis method is summarized in Test Example 2. The above content is a content measured according to the above Test Example 2, and may be the sulfur content confirmed when the sum of the carbon content (C), sulfur content (S), and sulfur content (S) confirmed at the measurement point (C+S+S) is set to 100 weight%.

[0101] The specific location at the bonding interface for measuring the above content is as described in Equation 1.

[0102] If the above plastic plate includes a filler component in addition to the resin component, △S can also be satisfied at the point where the resin component and the filler are present together and / or at the point where only the resin component is present among the bonding interfaces.

[0103] For example, the upper limit of the absolute value of the above △S may be approximately 50, 45, 40, 35, 30, 25, 20, or 15, and the lower limit may be approximately 0, 5, 10, or 15. The absolute value of the above △S 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. The unit of the above △S is %. The above △S may be positive or negative, and for example, may be negative.

[0104] As described above, the bonding interface of the bipolar plate exhibits excellent bonding strength under harsh conditions as described above, while simultaneously maintaining stable airtightness of the bonding strength. In this case, airtightness is a characteristic that restricts the movement of fluid to the bonding interface. A method for evaluating such airtightness is summarized in Test Example 4. The airtightness referred to in this specification is a value measured at the point where He gas is injected for 288 hours at a pressure of 1 bar according to the test method presented in Test Example 4.

[0105] The upper limit of the above airtightness may be approximately 990, 900, 600, 300, 100, 50, 10, 5, or 3, and the lower limit may be approximately 0, 0.5, 1, or 1.5. The unit of the above airtightness is ×10 -11 Pa·m 3 / s. The above confidentiality 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.

[0106] In order to secure the above excellent bonding strength characteristics and airtightness, the surface shape of the metal plate and / or the manufacturing method of the bipolar plate can be controlled.

[0107] For example, an uneven surface may exist on the surface of the metal plate, specifically, at least on the surface in contact with the plastic plate (e.g., the aforementioned seating surface).

[0108] In one example, the above-mentioned uneven shape may include an anchoring shape.

[0109] Although not specifically limited, the above anchoring shape may be advantageous for effectively securing the desired excellent bonding strength and airtightness for a bipolar plate manufactured by a heating and pressurizing method among the methods described below, and / or for a bipolar plate in which the plastic plate comprises an amorphous polymer.

[0110] Figure 8 is an example of the side shape of the anchoring shape.

[0111] As shown in FIG. 8, the anchoring shape may be formed with a burr (A1) protruding toward the plastic plate from the surface of the metal plate that contacts the plastic plate, and a groove (A2) that is recessed downward from the surface.

[0112] For example, the lower limit of the height (A1) of the anchoring shape 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] In cases where the height, depth, and width of the anchoring shape burr (A1) and the pitch of the anchoring shape pattern in the actual 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.

[0117] 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.

[0118] The irregularities of the metal plate may include depressions in other examples. A depression refers to a recessed area on the surface of the metal plate in the opposite direction to the plastic plate. Although not particularly limited, the depression may be advantageous for effectively securing the desired excellent bonding strength and airtightness for a bipolar plate having a plastic plate containing a crystalline polymer and / or a bipolar plate manufactured by an injection molding method among the methods described below.

[0119] For example, the above-mentioned depression may include a micron-sized depression and a nano-sized sub-depression existing within the micron-sized depression. The size of the depression can be obtained by photographing the surface on which the depression is formed using an SEM or the like, and may be the largest size in the shape of the depression observed in the photographed image, and may be the average (arithmetic mean) of a plurality of depressions.

[0120] In the above, the lower limit of the size of the indentation at the micron level may be approximately 0.5, 1, 1.5, 2, 2.5, 3, 3.5, or 4, and the upper limit may be approximately 20, 15, 10, 9, 7, 5, or 4.5. The above size 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 unit of the above size is μm.

[0121] The lower limit of the size of the nano-sized sub-depression existing within the micron-level depression may be approximately 1, 5, 10, 20, 30, 40, 50, 55, or 60, and the upper limit may be approximately 500, 450, 400, 350, 300, 250, 200, 150, 100, 90, 70, or 65. The size 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 unit of the size is nm.

[0122] The above-mentioned depression can be formed by a known wet surface treatment method, for example, by applying the surface treatment method disclosed in Korean Registered Patent Publication No. 10-2032078.

[0123] 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 (resin component) may be used.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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%.

[0135] The above plastic plate may include a filler as an additional component.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] For example, a metal plate applied to the above-mentioned bipolar plate may be used as the metal plate applied to the configuration of a conventional bipolar plate. Examples of such a metal plate may include titanium and / or alloys containing titanium. For example, a plate made of the above material may be used as the metal plate.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] The bipolar plate can be manufactured by attaching the metal plate and the plastic plate. In this case, the plastic plate may be attached to the metal plate after being manufactured in a form included in the final bipolar plate, or in another example, it may be attached to the metal plate while forming the said form.

[0146] This specification also discloses a method for manufacturing the bipolar plate. A desired bipolar plate can be manufactured by the method disclosed in this specification.

[0147] The above manufacturing method may include a step of heating and pressurizing the laminate of the plastic plate and the metal plate.

[0148] 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.

[0149] The type of metal plate applied to the above laminate is also as described above.

[0150] 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 (e.g., the aforementioned seating surface).

[0151] The surface of the metal plate in contact with the plastic plate may have the irregularities described above. In particular, in this method, it is advantageous to apply irregularities that include an anchoring shape among the irregularities.

[0152] In one example, the process of manufacturing the laminate can be adjusted to manufacture a bipolar plate having the aforementioned uniformity of spacing.

[0153] For example, the above laminate can be manufactured by positioning the hole area of ​​the plastic plate on a process surface having a protrusion formed thereon in a manner that fits into the protrusion, and then laminating a metal plate so as to be in contact with the protrusion.

[0154] A laminate can be manufactured in this manner, and a bipolar plate can be manufactured by heating and pressurizing the laminate.

[0155] The heating described above may be performed on only one side, either the upper or lower side, of the laminate, or on both sides. That is, a heater may be installed on the upper and / or lower side of the laminate and operated to perform the heating.

[0156] The above heating can be performed within an appropriate temperature range.

[0157] 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 T The ratio T T / T P It can be adjusted.

[0158] For example, the above ratio T T / T P The lower limit of may be approximately 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, 1.5, 1.4, 1.3, 1.2, or 1.1. The above T T / 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.

[0159] 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) T The ratio T T / T g It can be performed so that it is adjusted within a predetermined range.

[0160] For example, the above ratio T T / T g The lower limit of may be approximately 1, 1.05, 1.1, 1.15, 1.5, 2, 2.5, or 3, and the upper limit may be approximately 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 T / T g 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.

[0161] 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 / T g It can be performed so that it is adjusted within a predetermined range.

[0162] For example, the above ratio T P / T g The lower limit of 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 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 / T gIt 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.

[0163] 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 T 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.

[0164] A desired bipolar plate can be manufactured by adjusting the heating conditions as described above, and these adjustment conditions are particularly useful when the polymer is an amorphous polymer and an anchoring shape exists on the surface of the metal plate.

[0165] 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.

[0166] 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.

[0167] In such cases, the pressurization of the second stage can be performed by applying a load to the joint between the plastic plate and the metal plate of the laminate while maintaining the heating state of the first stage.

[0168] The above heating can be performed at a temperature that satisfies the aforementioned relationship.

[0169] 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 can be adjusted. For example, the above T 1 / The lower limit of 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.

[0170] 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.

[0171] The degree of the applied load in the above process may be controlled. For example, the lower limit of the load applied in the pressurization step or the second step may be approximately 0.01, 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, or 4, and the upper limit may be approximately 20, 15, 10, 8, 6, 4, 3, or 2.5. 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 equal to any upper limit arbitrarily selected from the listed upper limits. The unit of the applied load is kgf / mm² 2 am.

[0172] In the case where the above laminate is manufactured on a process surface having the aforementioned protrusion, the pressure may be applied only to the metal plate exposed in the hole area in the direction of the seating surface of the plastic plate.

[0173] A cooling process can be performed after the above heating and pressurization.

[0174] There are no specific restrictions on how this cooling process is performed.

[0175] 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.

[0176] 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 TThe 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, or 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.

[0177] Cooling at the above temperature Tc may be performed while applying a load to the laminate, or it may be performed without applying a load.

[0178] 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.

[0179] The cooling time at the above temperature Tc can be appropriately controlled.

[0180] 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.

[0181] 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.

[0182] In another example, the above bipolar plate can also be manufactured through an injection molding process.

[0183] This injection process can be carried out according to known procedures, for example, the procedures of a known insert injection process.

[0184] This may include the step of injecting a resin material that forms the plastic plate into the mold where the metal plate is positioned, while the metal plate described above is positioned within the mold of an injection molding machine.

[0185] The conditions of the injection process can be controlled to obtain the desired bipolar plate.

[0186] In one example, the conditions of the injection process can be adjusted so that the bonding strength of the attachment between the metal plate and the plastic plate in the bipolar plate is above a certain level.

[0187] For example, the lower limit of the bonding strength may be approximately 30, 35, 40, or 45, and the upper limit may be approximately 200, 150, 100, 90, 80, 70, 60, 50, or 45, although there is no specific limitation. 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.

[0188] To achieve the above bonding strength, the conditions of the injection process can be controlled. For example, the conditions can be adjusted differently depending on whether the injected resin material includes a crystalline polymer or an amorphous polymer.

[0189] For example, when the resin material being injected includes a crystalline polymer, the injection can be performed such that the absolute value of △T1 of Equation 7 below is at a certain level.

[0190] [Equation 7]

[0191] △T1 = 100 × (Ts - Tg) / Tg

[0192] In Equation 7, Ts is the average cylinder temperature during the injection step, and Tg is the glass transition temperature of the crystalline polymer.

[0193] The above average cylinder temperature is the arithmetic mean of the nozzle temperature of the injection molding machine and the temperature of the zone of the cylinder's heater band during the injection process. Typically, there are at least three zones in the heater band of an injection molding machine. Among these zones, the zone closest to the nozzle of the injection molding machine is typically called the H1 zone, the zone closest to the hopper is typically called the H3 zone, and the H2 zone exists between the H1 and H3 zones. Therefore, in the above case, the above average cylinder temperature is the arithmetic mean of the nozzle temperature, the temperature of the H1 zone, the temperature of the H2 zone, and the temperature of the H3 zone. Of course, depending on the injection molding machine, the H2 zone may be divided into multiple parts, resulting in more than three zones; in such cases, the above average cylinder temperature is calculated by reflecting the temperature of each divided zone.

[0194] Meanwhile, the lower limit of the absolute value of △T1 in Equation 7 may be approximately 150, 170, 190, 210, 230, 250, 270, or 280, and the upper limit may be approximately 300, 295, 290, 285, 280, 275, 270, 265, or 260. The above △T1 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. The unit of the above △T1 is %. The above △T1 may be positive or negative.

[0195] When the resin material includes a crystalline polymer, the injection process can be performed such that the absolute value of △T2 of Equation 8 below is within a predetermined range.

[0196] [Equation 8]

[0197] △T8 = 100 × (T N - T H3 ) / T H3

[0198] T in Equation 8 N is the nozzle temperature of the cylinder at the above injection step, and T H3 is the temperature of the front zone of the cylinder during the injection step. In the above, the front zone refers to the area closest to the cylinder's hopper. For example, as described above, the temperature of the area closest to the hopper among the areas of the cylinder's heater band may be the temperature of the front zone.

[0199] The upper limit of the absolute value of △T2 in Equation 8 may be approximately 15, 14, 13, 12, 11, 10, 9, or 8, and the lower limit may be approximately 1, 2, 3, 4, 5, 6, 7, 8, or 9. The above △T2 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. The unit of the above △T2 is %. The above △T2 may be positive or negative.

[0200] When the resin material includes a crystalline polymer, the injection process can be performed such that the absolute value of △T3 of the following Equation 9 is within a predetermined range.

[0201] [Equation 9]

[0202] △T3 = 100 × (Ts - Tm) / Tm

[0203] In Equation 9, Ts is the average cylinder temperature during the injection step, and Tm is the melting point of the crystalline polymer.

[0204] The details of the above Ts are as in Equation 7.

[0205] The upper limit of the absolute value of △T3 in Equation 9 may be approximately 30, 28, 26, 24, 22, 20, 18, or 16, and the lower limit may be approximately 5, 7, 9, 10, 12, 14, 15, or 20. The above △T3 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. The unit of the above △T3 is %. The above △T3 may be positive or negative.

[0206] When the resin material includes a crystalline polymer, the injection process can be applied to a crystalline polymer in which the absolute value of △T4 of the following Equation 10 is within a predetermined range.

[0207] [Equation 10]

[0208] △T4 = 100 × (Tm - Tg) / Tg

[0209] In Equation 10, Tg is the glass transition temperature of the crystalline polymer, and Tm is the melting point of the crystalline polymer.

[0210] The lower limit of the absolute value of △T4 in Equation 10 may be approximately 50, 150, or 200, and the upper limit may be approximately 600, 550, 500, 450, 400, 350, 300, or 250. The above △T4 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 unit of the above △T4 is %. The above △T4 may be positive or negative.

[0211] The above process can be performed under the temperature conditions mentioned above.

[0212] Additionally, the pressure for injecting a resin material containing a crystalline polymer during the above process may be controlled. At this time, the lower limit of the injection pressure may be approximately 90, 95, 100, 105, 110, 115, 120, 125, 130, or 135, and the upper limit may be approximately 1,000, 800, 600, 400, 200, 180, 160, or 140. The injection pressure 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 equal to any upper limit arbitrarily selected from the listed upper limits. The unit of the injection pressure is bar.

[0213] Additionally, the injection speed of the resin material containing the crystalline polymer can be controlled during the above process. At this time, the lower limit of the injection speed may be approximately 80, 100, 115, 120, 150, 200, 250, 280, 290, or 300, and the upper limit may be approximately 1,500, 1,000, 800, 600, 400, 350, 200, or 140. The injection speed 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 equal to any upper limit arbitrarily selected from the listed upper limits. The unit of the injection pressure is mm / sec.

[0214] When the resin material includes a crystalline polymer, the injection process can be performed such that the absolute value of △T5 of the following Equation 11 is within a predetermined range.

[0215] [Equation 11]

[0216] △T5 = 100 × (T T - Tg) / Tg

[0217] In Equation 11, Tg is the glass transition temperature of the crystalline polymer, and T T is the temperature of the mold in the above injection process.

[0218] The lower limit of the absolute value of △T5 in Equation 11 may be approximately 25, 30, 35, 40, 45, 50, 55, or 60, and the upper limit may be approximately 200, 150, 100, 90, 80, 70, 60, 50, or 40. The above △T5 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 unit of the above △T5 is %. The above △T5 may be positive or negative.

[0219] As with a conventional injection process, the above process may additionally include a step of applying holding pressure within the mold filled with the resin material after the injection.

[0220] In such cases, the above holding pressure can be performed such that △P1 of Equation 12 below is within a predetermined range.

[0221] [Equation 12]

[0222] △P1 = P × t

[0223] In Equation 12, P is the holding pressure applied during the holding pressure application step, and t is the time for applying the holding pressure.

[0224] The lower limit of △P1 in Equation 12 may be approximately 200, 400, 600, 800, 850, 870, 890, or 900, and the upper limit may be approximately 2,000, 1,500, 1,000, 950, 900, 800, 700, or 650. The above △P1 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 unit of the above △P1 is bar·sec.

[0225] The lower limit of t in Equation 12 above may be approximately 1, 2, 3, 4, 5, 6, 7, or 8, and the upper limit may be approximately 20, 18, 16, 14, 12, or 10. The above t 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 above t is sec.

[0226] The types of metal plates and crystalline polymers used in the above process and specific details regarding them are as described in the bipolar plate section above.

[0227] Accordingly, the surface of the metal plate, in particular the surface in contact with at least the plastic plate, may include the aforementioned irregularities, for example, the depressions.

[0228] Meanwhile, in the case where the resin material injected above includes an amorphous polymer, the process can be performed such that the absolute value of △P1 of Equation 12 in the holding pressure application process is at a certain level.

[0229] In such cases, the lower limit of △P1 in Equation 12 above may be approximately 1,000, 1,500, or 2,000, and the upper limit may be approximately 20,000, 15,000, 10,000, 8,000, 6,000, 4,000, 3,500, 3,000, or 2,500. The above △P1 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 unit of the above △P1 is bar·sec.

[0230] In such cases, the lower limit of t in Equation 12 above may be approximately 1, 3, 5, 7, 9, 11, or 13, and the upper limit may be approximately 30, 28, 26, 24, 22, 20, 18, or 16. The above t 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 above t is sec.

[0231] When the resin material includes an amorphous polymer, injection can be performed so that △T1 of Equation 7 is within a predetermined range.

[0232] The lower limit of the absolute value of △T1 in Equation 7 above may be approximately 50, 70, 90, 95, or 100, and the upper limit may be approximately 500, 450, 400, 350, 300, 250, 200, 180, 160, 140, 120, 110, or 100. △T1 may be within a range equal to or less than any upper limit arbitrarily selected from the listed upper limits; or within a range equal to or greater than 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 unit of △T1 is %. △T1 may be positive or negative.

[0233] When the resin material includes an amorphous polymer, the injection process can be performed such that the absolute value of △T2 of Equation 8 is within a predetermined range.

[0234] In such cases, the lower limit of the absolute value of △T2 in Equation 8 above may be approximately 5, 10, 15, 20, 25, or 30, and the upper limit may be approximately 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, or 35. The △T2 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. The unit of the △T2 is %. The △T2 may be positive or negative.

[0235] In the case of including an amorphous polymer, injection can be performed under the above temperature conditions.

[0236] In the above process, the pressure for injecting a resin material containing an amorphous polymer can be controlled. At this time, the lower limit of the injection pressure may be approximately 90, 95, 100, 105, 110, 115, 120, 125, 130, or 135, and the upper limit may be approximately 1,000, 800, 600, 400, 200, 180, 160, or 140. The injection pressure 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 unit of the injection pressure is bar.

[0237] In the above process, the injection speed of injecting a resin material including an amorphous polymer can be controlled. At this time, the lower limit of the injection speed may be approximately 80, 100, 115, 120, 150, 200, 250, 280, 290, or 300, and the upper limit may be approximately 1,500, 1,000, 800, 600, 400, or 350. The injection speed 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 unit of the injection pressure is mm / sec.

[0238] When the resin material includes an amorphous polymer, the injection process can be performed such that the absolute value of △T5 of Equation 11 is within a predetermined range.

[0239] The lower limit of the absolute value of △T5 in Equation 11 may be approximately 5, 7, 9, 11, or 13, and the upper limit may be approximately 50, 45, 40, 35, 30, 25, 20, or 15. The above △T5 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 unit of the above △T5 is %. The above △T5 may be positive or negative, and may be negative in appropriate examples.

[0240] The types of metal plates and amorphous polymers used in the above process and specific details regarding them are as described in the bipolar plate section above.

[0241] Accordingly, the surface of the metal plate, in particular the surface in contact with at least the plastic plate, may include the aforementioned irregularities.

[0242] The resin material used in the process described above includes the amorphous polymer or crystalline polymer, and may also include other materials included in the plastic plate. Accordingly, the resin material may include the aforementioned filler. In such cases, the type and content of the filler, etc., are as described in the bipolar plate section above.

[0243] Following the above injection and holding pressure application processes, if necessary, an appropriate cooling process is performed, and subsequently, by demolding, the desired bipolar plate can be obtained.

[0244] 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.

[0245] This specification discloses a bipolar plate, a method for manufacturing the same, and uses thereof. This specification discloses a bipolar plate that is economically manufactured by bonding a metal plate and a plastic plate and is advantageous for weight reduction. The bond between the metal plate and the plastic plate can be stably maintained even under harsh conditions, such as being maintained under acidic conditions or under high temperature and high temperature conditions. This specification discloses a method for manufacturing the bipolar plate and uses thereof.

[0246] Figure 1 is an example of a plastic plate of a bipolar plate.

[0247] Figure 2 is an example of the bonding process between a plastic plate and a metal plate for manufacturing a bipolar plate.

[0248] Figure 3 is a drawing for explaining a metal plate.

[0249] Figure 4 is an example of a bipolar plate.

[0250] Figure 5 is an example of a bipolar plate.

[0251] Figure 6 is an example of a bipolar plate.

[0252] Figure 7 is a diagram illustrating the point where the gap is measured on the bipolar plate.

[0253] Figure 8 is an example of an anchoring shape.

[0254] Figure 9 is a drawing illustrating a specimen for measuring bonding strength.

[0255] Figure 10 is an SEM image of the anchoring shape.

[0256] Figure 11 is an image of a depression on the surface of a metal plate.

[0257] Figure 12 is an image of a depression on the surface of a metal plate.

[0258] Figure 13 is an example of the bonding process between a plastic plate and a metal plate for the manufacture of a bipolar plate.

[0259] Figure 14 is an image of the bonding interface between the plastic plate and the metal plate in a bipolar plate.

[0260] Figure 15 is an image of the bonding interface between the plastic plate and the metal plate in a bipolar plate.

[0261] Figure 16 is an example of a specimen for evaluating airtightness.

[0262] Figure 17 is a drawing illustrating a specimen for airtightness evaluation.

[0263] FIG. 18 is a drawing for illustrating a specimen for airtightness evaluation.

[0264] The bipolar plate is specifically described through the following examples, but the scope of the method is not limited by the following examples.

[0265]

[0266] Preparation Example 1. Metal plate surface treatment (dry treatment)

[0267] In order to manufacture a bipolar plate with a plastic plate (1000) and a metal plate (2000) attached as exemplified in FIG. 2, surface treatment was performed on the metal plate (2000). A titanium plate (melting point: approximately 1,668°C) was used as the metal plate (2000). The shape of the metal plate being 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. Additionally, 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 portions of the metal plate, excluding the convex portions. The 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 portions requiring surface treatment using the laser irradiation device. The 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 45 W, and laser energy was applied with a repetition rate of approximately 70 kHz (Pulse mode). Figure 10 is an image (SEM) of the anchoring shape formed by the surface treatment. In the above anchoring shape, the average height of the burr was about 60 μm, the average depth of the anchoring shape was about 180 μm, the average width of the anchoring shape was about 40 μm, and the average pitch of the anchoring shape pattern was about 150 μm.

[0268]

[0269] Preparation Example 2. Metal plate surface treatment (wet treatment)

[0270] Surface treatment was performed on the same portion of the metal plate as in Preparation Example 1 through wet treatment. The wet treatment was performed in the manner disclosed in Example 1 of Korean Registered Patent Publication No. 10-2032078. Figures 11 and 12 show the surface of the metal after the surface treatment. Figure 11 is the result of photographing the surface of the metal after surface treatment at a magnification of 2,000 times, and Figure 12 is the result of photographing the surface of the metal after surface treatment at a magnification of 100,000 times. From Figure 11, it can be seen that a depression with an average size of approximately 4.18 μm is formed on the surface of the wet-surface-treated metal. Figure 12 is the result of observing the depression with an average size of approximately 4.18 μm by further magnification, and through this, it can be confirmed that pores with an average size of 60.24 nm exist within each depression.

[0271]

[0272] Example 1

[0273] A bipolar plate was manufactured by attaching a plastic plate (2000) and a metal plate (1000) as exemplified in FIG. 13. When attaching, the surface-treated area of ​​the metal plate (1000) was laminated so as to be in contact with the plastic plate (2000).

[0274] The plastic plate used was manufactured using a material in which polysulfone (PSU) and glass fiber were mixed in a weight ratio of approximately 8:2 (PSU:Glass fiber). The PSU was an amorphous plastic with a glass transition temperature of approximately 187°C. The glass transition temperature was measured according to ASTM E1356 standards 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. The plastic plate was manufactured using the above material via a well-known plastic molding method.

[0275] The metal plate of Manufacturing Example 1 was used as the above metal plate.

[0276] Attachment was performed on the above laminate by applying heat and pressure.

[0277] The heating and pressurization described above were performed using a press machine (QM900A-U, Qumersys) 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. The laminate was placed inside the machine (QM900A-U). At this time, the plastic plate of the laminate was positioned at the bottom, and the metal plate was positioned on top of it.

[0278] In the above state, the laminate was heated (heating process). Heating was performed by simultaneously operating the lower heater located on the plastic plate side of the laminate and the upper heater located on the metal plate side. During heating, the upper heating temperature was set to approximately 220°C, and the lower heating temperature was set to approximately 140°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). 2 A load of approximately 2.12 kgf was applied per ) and the above 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).

[0279]

[0280] Example 2

[0281] A bipolar plate of the same shape as Example 1 was manufactured by changing the resin material and metal plate and applying an injection molding process. The injection molding process was performed using a vertical injection molding machine (Wonil Hydraulic Co., WL-VTL-120RN4).

[0282] The resin material used for the above injection process was a material prepared in pellet form by mixing PPS (Polyphenylene sulfide) and glass fiber. The mixing ratio within the material 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. The glass transition temperature and melting point were measured according to the method used to measure the glass transition temperature in Example 1. The metal plate was mounted inside the mold of an injection molding machine, and the resin material was injected to manufacture a bipolar plate, with the process conditions adjusted as shown in Table 1 below.

[0283]

[0284] Comparative Examples 1 and 2

[0285] Comparative Example 1 is a bipolar plate manufactured by applying an injection molding process using the same resin material as Example 1 as the resin material, and Comparative Example 2 is a bipolar plate manufactured by applying an injection molding process using the same material as Example 2 as the resin material. In this process, the conditions of the injection molding process were controlled as shown in Table 1 below.

[0286] In all processes (including Example 1), the clamping force of the injection process (the force applied to keep the mold closed during the injection process) was maintained at 120 ton. In addition, in all processes (including Example 1), cooling was performed by applying natural cooling.

[0287] In Table 1 below, H3 of the cylinder temperature is the temperature of the rear zone closest to the hopper in the injection process, H1 is the temperature of the front zone closest to the nozzle, and H2 is the temperature of the central zone between the H1 and H2 zones. In addition, holding pressure refers to the pressure applied after the resin material is filled into the mold.

[0288] In Table 1 below, the metal plate is a type of metal plate applied to the injection process, and the number indicates the number of the manufacturing example.

[0289] Example Comparative Example 212 Metal Plate Manufacturing Example 2 Manufacturing Example 1 Manufacturing Example 1 Cylinder Temperature (°C) Nozzle 3 20 400 320 H 1 3 40 400 340 H 2 3 5 39 5 3 35 H 3 29 5 300 29 5 Cylinder Pressure (bar) 1 35 1 35 1 3 5 Cylinder Speed ​​(mm / sec) 3 00 300 300 Holding Pressure Applied Pressure (bar) 1 00 1 40 100 Time (sec) 9 1 5 9 Cooling Time (sec) 9 9 9 9 9 9 9 9 9 Mold Temperature (°C) 1 45 1 45 1 60

[0290]

[0291] Test Example 1. Evaluation of bonding strength under accelerated conditions

[0292] The bonding strength of the bipolar plate was measured.

[0293] The bonding strength was evaluated in the following manner. A specimen was prepared by cutting a plastic plate and a metal plate attached to a bipolar plate, wherein the cut specimen was cut to include the bonding portion between the plastic plate and the metal plate. As shown in FIG. 9, the cutting was performed 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) was approximately 9 mm, and the width (the length of the bonding surface (B) in the direction perpendicular to B) was approximately 12.5 mm. Additionally, the length of the protruding portion (C) of the plastic plate (100) that is not the bonding surface was approximately 36 mm, and the length of the protruding portion (A) of the metal plate (200) that is not the bonding surface was approximately 35 mm. The bonding strength was evaluated for the specimen.

[0294] 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.

[0295] Bonding strength was measured on specimens prepared on a bipolar plate immediately after preparation, and additionally measured while maintaining the bipolar plate in a constant temperature and humidity chamber at a temperature of 130°C and a relative humidity of 85%. In Table 2 below, 0h represents the result for the bipolar plate immediately after preparation, and 96h, 192h, and 288h represent the result for specimens maintained in the constant temperature and humidity chamber for 96 hours, 192 hours, and 288 hours, respectively.

[0296] Example Comparative Example 1 2 12 Bonding Strength (MPa) 0 h 49.6 4 2.19 3 2.6 4 1.8 19 6 h 46.7 8 6 3 2.0 8 9 14.3 6 9 2 2.8 5 4 19 2 h 47.2 7 4 3 0.4 18 17.1 26 2 2.9 5 5 28 8 h 45.4 4 3 3.9 5 4 19.4 9 8 2 6.6 36 △ P 96 63112783△P 192 5399182△P 288 9246857

[0297] △P in Table 2 96 , △P 192 and △P 288ε₀ is the rate of change of bonding strength measured according to Equations 1 to 3, respectively. From the results in Table 2, it can be confirmed that the bipolar plate of the example exhibits high bonding strength immediately after manufacturing and maintains excellent bonding strength even during maintenance under high temperature and high humidity conditions. On the other hand, in the case of the comparative example, it can be confirmed that the initial bonding strength is not high, or even if it is high, the bonding strength drops significantly during maintenance under high temperature and high humidity conditions.

[0298]

[0299] Test Example 2. Composition Analysis

[0300] The composition of the plastic at the bonding interface between the metal plate and the plastic plate of the bipolar plate was analyzed using EDAX (Energy Dispersive X-ray Analysis). The JEOL JSM-7610Plus product was used as the analysis instrument. For the composition analysis, the bonding interface between the metal plate and the plastic plate of the bipolar plate was exposed using a microtome process, and the results were verified.

[0301] The microtoming process was performed using a PT3D machine from RMC Boeckeler. A bipolar plate was fixed to a jig and cut using the blade of the machine. At this time, the blade angle was set perpendicular to the joint surface between the metal plate and the plastic plate of the bipolar plate, and the cutting speed was set to the value that provides the best cross-sectional quality within the range of 10 mm / sec to 50 mm / sec.

[0302] Next, a sample was prepared by coating Pt to a thickness of about 10 nm through plasma coating deposition on a surface including the bonding interface exposed by the above cutting.

[0303] The above sample was mounted in the SEM chamber. The pressure inside the SEM chamber is 1×10⁻⁶ -6A vacuum state of mtorr or higher was maintained. Under the above conditions, an electron beam was irradiated onto the sample, and the resulting characteristic X-rays were detected by an EDAX detector to obtain a spectrum. The C, O, and S content was obtained by analyzing the spectrum. The electron beam acceleration voltage was set to 15 kV, the probe current was set to 5 nA, the data acquisition time was set to 300 seconds, and the Region of Interest (ROI) was set to include an energy range capable of detecting peaks of C, O, and S.

[0304] The above analysis was performed by measuring the bipolar plate immediately after preparation and again after maintaining the bipolar plate in an aqueous sulfuric acid solution for 2,000 hours. A 0.5 M aqueous H2SO4 solution (pH=1) was used as the aqueous sulfuric acid solution, and the bipolar plate was maintained in the solution for approximately 2,000 hours at room temperature (approx. 25°C). Composition analysis was evaluated in the region where the resin and filler are present together (resin + GF) and the region where only the resin is present in the cross-section of the interface. If necessary, composition analysis was performed by designating two or more points for each region.

[0305] The above composition analysis was performed on the bipolar plate of Example 1 and the bipolar plate of Example 2. Fig. 14 is the result of the above measurement performed on Example 1, showing the cross-section before treatment with an aqueous sulfuric acid solution. Fig. 15 is the result of the above measurement, showing the cross-section after treatment with an aqueous sulfuric acid solution.

[0306] Tables 3 and 4 below summarize the above measurement results.

[0307] In the results of Tables 3 and 4 below, Fresh refers to the results for the bipolar plate before treatment with aqueous sulfuric acid solution, and Treated refers to the results for the bipolar plate after treatment with aqueous sulfuric acid solution.

[0308] Table 3 below shows the contents of C and O when the sum of the contents of C and O in the compositional analysis results for Example 1 is set to 100 wt%, and Table 4 below shows the contents of C, O, and S when the sum of the contents of C, O, and S in the compositional analysis results for Example 1 is set to 100 wt%. Therefore, the units in Tables 3 and 4 are wt%. In the region where the resin and filler are present together at the bonding interface (resin + GF), the composition of the resin was uniform overall, so measurements were taken at only one point. In addition, for the region where only resin is present (resin), measurements were taken at four or three points for further verification.

[0309] Sample ROI Setting Area COFresh Resin+GF73.1426.86 Resin 77.9022.1078.5521.4578.8521.1578.8821.12 Treated Resin+GF72.6627.34 Resin 77.5222.4877.9822.0278.2421.76

[0310] Sample ROI Setting Area COSFresh Resin+GF76.0318.825.16 Resin 80.1014.205.7080.6213.775.6180.8413.325.8480.8713.365.77 Treated Resin+GF75.8517.836.32 Resin 79.8113.676.5280.1613.346.5080.9412.456.61

[0311]

[0312] Tables 5 and 6 below are the results of the above analysis for Comparative Example 2.

[0313] Table 5 below shows the content of C and O when the sum of the C and O contents in the compositional analysis results for Comparative Example 2 is set to 100 wt%, and Table 6 below shows the content of C, O, and S when the sum of the C, O, and S contents in the compositional analysis results for Comparative Example 2 is set to 100 wt%. Accordingly, the units of Tables 5 and 6 are wt%.

[0314] Sample ROI Setting Area COFresh Resin+GF5 6.48 43.5 25 7.3 342.67 Resin 90.6 19.39 Treated Resin+GF5 0.96 49.04 Resin 83.9 916.01 86.8 013.2 83.5 316.4 783.3 916.61

[0315] Sample ROI Setting Area COSFresh Resin+GF6 1.34 17.75 20.91 62.03 17.22 20.75 Resin 71.88 1.21 26.91 Treated Resin+GF5 7.60 28.35 14.05 Resin 76.91 3.71 19.38 77.66 2.82 19.52 76.36 3.76 19.88 76.213.78 20.01

[0316] Test Example 3. Evaluation of bonding strength under acidic conditions

[0317] The bonding strength was evaluated in the same manner as in Test Example 1. The bonding strength was measured on the manufactured bipolar plate (0 h in Table 7 below), and evaluated after being removed following maintenance in an aqueous sulfuric acid solution under the same conditions as in Test Example 2. In Table 7 below, 1000 h represents the result for a specimen maintained in the aqueous sulfuric acid solution for 1000 hours, 1500 h represents the result for a specimen maintained in the aqueous sulfuric acid solution for 1500 hours, and 2000 h represents the result for a specimen maintained in the aqueous sulfuric acid solution for 2000 hours. The evaluation was performed on Example 1 and Comparative Example 2. The unit of bonding strength in Table 2 is MPa.

[0318] Example 1 Comparative Example 20h 49.60 41.81 1000h 46.52 30.80 1500h 34.88 24.08 2000h 36.76 29.43

[0319] Test Example 4. Confidentiality Evaluation

[0320] An airtightness evaluation was performed. The airtightness evaluation was conducted by fabricating a specimen in the form shown in FIG. 16. The specimen was manufactured using a metal plate and a plastic plate of the same material as that used in the manufacture of the bipolar plate. FIG. 17 is a cross-sectional view of the specimen, and FIG. 18 is a top view of the specimen. As shown in the drawings, the specimen was manufactured in a form where a metal plate (1000) processed into a rod shape is inserted into the hole of a plastic plate (2000) processed into a circular shape having a hole in the center. The processing form of the plastic plate (2000) is the same as the plug of the vacuum chamber described later. In FIG. 17, D O and D I is the diameter of each circularly processed plastic plate (2000), D O is approximately 50 mm, and D I The length is approximately 20 mm. In addition, the metal plate was processed into a bar shape (1000) with a rectangular cross-section having a width and length of 12 mm and 40 mm, respectively. Also, T1 and T2 in FIG. 17 are approximately 1.5 mm and 2 mm, respectively.

[0321] The above specimen was manufactured in the same manner as in the example or comparative example. That is, the portion of the metal rod (1000) in contact with the plate (1000) in the specimen was subjected to surface treatment as in the example or comparative example, and the injection conditions for manufacturing the specimen were also performed in the same manner as in the example or comparative example.

[0322] Next, the internal volume is 140,000 cm³ 3 A vacuum chamber with a gas inlet was prepared. Subsequently, the gas inlet was blocked with a specimen, and the vacuum level inside the chamber was set to approximately 5.5 × 10⁻⁶.-11 Pa·m 3 It was maintained at / s. Then, with the gas inlet blocked by the specimen, the gas inlet was connected to a gas injection line, and He gas was applied through the line at a pressure of about 0.1 bar.

[0323] If the above gas inlet is not stably sealed by the above specimen, the pressure inside the chamber increases due to the injection of the He gas.

[0324] Table 8 below shows the results of evaluating the pressure inside the vacuum chamber over time when using the specimen prepared according to the contents of Example 2. The unit of each value in Table 8 below is ×10 -11 Pa·m 3 / s is.

[0325] Example 20 Hours 6.3296 Hours 2.15192 Hours 1.8288 Hours 1.73

[0326]

[0327] From the results of Table 8, it can be confirmed that the specimen of Example 2 maintains stable airtightness of the metal-plastic joint even as time passes.

Claims

1. Metal plate; and It includes a plastic plate having a frame area surrounding a hole area, and The metal plate is attached to the plastic plate in the hole area, and △P of Equation 1 below 96 Bipolar plate with an absolute value of 100% or less: [Equation 1] △P 96 = 100 × (P0- P 96 ) / P 96 P in Equation 1 96 Silver is the bonding strength of the metal plate and the plastic plate after being maintained at 130°C and 85% relative humidity for 96 hours, and P0 is the bonding strength of the metal plate and the plastic plate before being maintained at 130°C and 85% relative humidity for 96 hours.

2. A bipolar plate according to claim 1, wherein one or more selected from the group consisting of a hole configured to move fluid in a direction parallel to the normal of the metal plate surface and a groove configured to move fluid in a direction perpendicular to the normal of the metal plate surface are formed in the frame region.

3. In Paragraph 1 or 2, △P of Formula 2 below 192 Bipolar plate with an absolute value of 100% or less: [Equation 2] △P 192 = 100 × (P0- P 192 ) / P 192 P in Equation 2 192 Silver is the bonding strength of the metal plate and plastic plate maintained at 130°C and 85% relative humidity for 192 hours, and P0 is the bonding strength of the metal plate and plastic plate before maintaining at 130°C and 85% relative humidity for 192 hours.

4. In any one of paragraphs 1 to 3, △P of Formula 3 below 288 Bipolar plate with an absolute value of 80% or less: [Equation 3] △P 288 = 100 × (P0- P 288 ) / P 288 In Equation 3, P 288 Silver is the bonding strength of the metal plate and plastic plate maintained at 130°C and 85% relative humidity for 288 hours, and P0 is the bonding strength of the metal plate and plastic plate before maintaining at 130°C and 85% relative humidity for 288 hours.

5. A bipolar plate according to any one of claims 1 to 4, wherein the bonding strength P0 of Formula 1 is 35 MPa or more.

6. In any one of paragraphs 1 to 5, 9.9 × 10 -9 Pa·m 3 A bipolar plate exhibiting less than / s of airtightness.

7. A bipolar plate according to any one of claims 1 to 6, comprising two plastic plates, wherein the two plastic plates are attached to both sides of a metal plate.

8. A bipolar plate according to any one of claims 1 to 7, wherein irregularities are formed on the surface of the metal plate that contacts the plastic plate.

9. In claim 8, the bipolar plate comprises an anchoring shape formed by a burr protruding from a surface in contact with the seating surface of a metal plate and a groove recessed downward from said surface.

10. A bipolar plate according to claim 9, wherein the height of the burr is within the range of 5 μm to 150 μm, the depth of the anchoring shape is within the range of 50 μm to 500 μm, and the width of the anchoring shape is within the range of 1 μm to 160 μm.

11. A bipolar plate according to claim 8, wherein the irregularities include a depression with a size within the range of 0.5 μm to 10 μm, and within the depression with a size within the range of 0.5 μm to 10 μm, a sub-depression with a size of 10 nm to 400 nm exists.

12. In claim 9, the plastic plate is a bipolar plate comprising an amorphous polymer.

13. In claim 11, the plastic plate is a bipolar plate comprising a crystalline polymer.

14. In any one of claims 1 to 13, the metal plate is a bipolar plate that is a titanium plate or a titanium alloy plate.

15. An electrolytic device comprising a bipolar plate according to any one of claims 1 to 14.

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