Bipolar plate structure, electrolytic bath and hydrogen production system

Abstract

The utility model discloses a bipolar plate structure, an electrolytic bath and a hydrogen production system. The bipolar plate structure comprises a bipolar plate and a porous transmission layer, the bipolar plate is provided with a first main surface and a second main surface which are arranged back to back, the porous transmission layer is fixed on the first main surface, the porous transmission layer and the bipolar plate form an integrated structural member, and coatings are arranged on the second main surface and the surface, back to the bipolar plate, of the porous transmission layer. And the porous transmission layer is fixedly connected with the bipolar plate through diffusion welding. According to the bipolar plate structure, the porous transmission layer is fixed on the first main surface, so that a coating does not need to be arranged at the joint of the bipolar plate and the porous transmission layer, a part of coating area is reduced, and the coating cost is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by water electrolysis, in particular to a bipolar plate structure, an electrolytic cell and a hydrogen production system. BACKGROUND

[0002] PEM electrolytic cells are commonly used for hydrogen production by water electrolysis. An electrolytic cell is the core structure of a PEM electrolytic cell, and the electrolytic cell is provided with a bipolar plate, a porous transport layer and a gas diffusion layer. In the related art, the bipolar plate and the porous transport layer are independent of each other, and the surface of the bipolar plate and the surface of the porous transport layer need to be coated to prevent the bipolar plate and the porous transport layer from passivation and oxidation, which increases the contact resistance. However, the area of the bipolar plate and the porous transport layer that needs to be coated is large, which increases the coating cost. UTILITY MODEL CONTENT

[0003] The present application aims to at least partially solve one of the above technical problems in the prior art. To this end, the present application provides a bipolar plate structure, which is beneficial to reduce the coating area and save the coating cost.

[0004] The present application also provides an electrolytic cell having the bipolar plate structure.

[0005] The present application also provides a hydrogen production system having the electrolytic cell.

[0006] The bipolar plate structure according to the embodiments of the present application comprises a bipolar plate and a porous transport layer. The bipolar plate has a first main surface and a second main surface arranged away from each other. The porous transport layer is fixed on the first main surface and forms an integral structure with the bipolar plate. A coating is arranged on the surface of the second main surface and the porous transport layer away from the bipolar plate. The porous transport layer is fixedly connected with the bipolar plate by diffusion welding.

[0007] The bipolar plate structure according to the embodiments of the present application has the porous transport layer fixed on the first main surface, so that the coating does not need to be arranged at the bonding surface of the bipolar plate and the porous transport layer. Thus, the coating area is reduced and the coating cost is saved.

[0008] According to some embodiments of the present application, the first main surface and / or the second main surface is provided with a flow channel, and the surface roughness Ra of the flow channel is less than 5 μm.

[0009] According to some embodiments of the present application, the porous transport layer comprises one or more of a porous titanium plate, a titanium fiber felt and a titanium mesh.

[0010] According to some embodiments of the present application, the porous transport layer comprises a porous titanium plate, and the porous titanium plate is a three-dimensional porous titanium plate or a two-dimensional porous titanium plate.

[0011] According to some embodiments of the present application, the porous titanium plate is a three-dimensional porous titanium plate, and the three-dimensional porous titanium plate has first holes inside;

[0012] The thickness of the three-dimensional porous titanium plate ranges from 0.3 mm to 2 mm, and / or the porosity of the three-dimensional porous titanium plate ranges from 25% to 50%, and / or the pore size of the first holes ranges from 10 μm to 100 μm.

[0013] According to some embodiments of the present application, the porous titanium plate is a two-dimensional porous titanium plate, and the two-dimensional porous titanium plate is provided with second holes;

[0014] The thickness of the two-dimensional porous titanium plate ranges from 0.1 mm to 1 mm, and / or the pore size of the second holes ranges from 0.1 mm to 0.5 mm.

[0015] According to some embodiments of the present application, the titanium fiber felt has third holes inside;

[0016] The thickness of the titanium fiber felt ranges from 0.15 mm to 2 mm, and / or the porosity of the titanium fiber felt ranges from 50% to 80%, and / or the pore size of the third holes ranges from 10 μm to 50 μm.

[0017] According to some embodiments of the present application, the titanium mesh includes a woven titanium mesh and / or a diamond-shaped stretched titanium mesh;

[0018] The thickness of the titanium mesh ranges from 0.3 mm to 5 mm, and / or the mesh number of the titanium mesh ranges from 30 to 200, and / or the wire diameter of the titanium mesh ranges from 0.2 mm to 0.5 mm.

[0019] According to some embodiments of the present application, the entire outer surface of the integral structure is provided with a coating.

[0020] The electrolytic cell according to the second aspect of the embodiments of the present application includes the bipolar plate structure described above.

[0021] The electrolytic cell according to the embodiments of the present application has the bipolar plate structure, which fixes the porous transport layer on the first major surface, so that the coating is not required at the bonding position of the bipolar plate and the porous transport layer, thereby reducing the coating area and saving the coating cost, and further saving the cost of the electrolytic cell.

[0022] The hydrogen production system according to the third aspect of the embodiments of the present application includes the electrolytic cell described above.

[0023] According to the hydrogen production system provided by the embodiment of the present application, the bipolar plate structure of the electrolytic cell is fixed with the porous transport layer on the first main surface, so that the coating is not arranged at the bonding position of the bipolar plate and the porous transport layer, thereby reducing the coating area and saving the coating cost, and further saving the cost of the electrolytic cell and the hydrogen production system.

[0024] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a top view of the bipolar plate structure according to the embodiment of the present application;

[0026] Figure 2 is a top view of the porous transport layer;

[0027] Figure 3 is a side view of the bipolar plate structure according to the embodiment of the present application;

[0028] Figure 4 is a side view of the bipolar plate structure and the membrane electrode stack according to the embodiment of the present application.

[0029] REFERENCE SIGNS

[0030] Bipolar plate structure 10, bipolar plate 1, first main surface 11, second main surface 12, porous transport layer 2, transport layer first side 21, transport layer second side 22, membrane electrode 3. DETAILED DESCRIPTION

[0031] The embodiments of the present application are described in detail below with reference to the accompanying drawings, in which the same or similar components have the same or similar reference numbers throughout. The embodiments described below are exemplary and are intended to explain the present application, and should not be understood as limiting the present application.

[0032] In the description of the present application, the terms "first", "second" are used only for the purpose of description, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] The following will be described in detail Figures 1-4 The bipolar plate structure 10 according to the embodiment of the present application is described in detail below.

[0034] Referring to Figures 1-3As shown, the bipolar plate structure 10 according to the embodiments of the present application comprises a bipolar plate 1 and a porous transport layer 2, the bipolar plate 1 is capable of providing gas-liquid flow channels to provide flow paths for gas-liquid in the electrolytic cell. The porous transport layer 2 plays an important role in conducting current and transporting gas, liquid and two-phase fluid in the electrolytic cell, directly affecting the energy efficiency and hydrogen production capacity of the electrolytic cell. The porous transport layer 2 can also provide a carrier for the catalyst, ensuring the best interaction between the reactants and the electrode, and achieving efficient electrolysis at high production rate.

[0035] The bipolar plate 1 has a first main surface 11 and a second main surface 12, the first main surface 11 and the second main surface 12 are arranged away from each other, the bipolar plate 1 is in a sheet structure, and the first main surface 11 and the second main surface 12 are the largest faces of the bipolar plate 1. The porous transport layer 2 is fixed on the first main surface 11, the porous transport layer 2 and the bipolar plate 1 form an integral structure, and a coating is arranged on the surface of the second main surface 12 and the porous transport layer 2 away from the bipolar plate 1. The coating can improve the oxidation resistance of the bipolar plate structure 10, thereby improving the durability of the bipolar plate structure 10.

[0036] Specifically, the porous transport layer 2 has a transport layer first side 21 and a transport layer second side 22, the transport layer first side 21 and the transport layer second side 22 are arranged away from each other. The transport layer first side 21 is attached to the first main surface 11, so that the coating is arranged on the second main surface 12 and the transport layer second side 22 of the porous transport layer 2, and the transport layer first side 21 attached to the first main surface 11 does not need to be coated, thereby saving coating materials and reducing the processing cost of the bipolar plate structure 10.

[0037] When the porous transport layer 2 completely covers the first main surface 11, the coating is arranged on the second main surface 12 and the transport layer second side 22 of the porous transport layer 2; when the porous transport layer 2 does not completely cover the first main surface 11, in addition to the coating arranged on the second main surface 12 and the transport layer second side 22 of the porous transport layer 2, the coating is also arranged on the region of the first main surface 11 not covered by the porous transport layer 2, and the transport layer first side 21 attached to the first main surface 11 does not need to be coated.

[0038] Optionally, the coating can be formed on the exposed surface of the bipolar plate 1 and the porous transport layer 2 by electroplating process, chemical vapor deposition process, etc.

[0039] Optionally, the coating can be a metal nitride coating, a metal carbide coating, a metal oxide coating, an alloy coating, a non-metal coating, etc.

[0040] In some embodiments, the coating can be platinum, graphene, etc.

[0041] According to the bipolar plate structure 10 of the embodiments of the present application, the porous transport layer 2 is fixed on the first main surface 11, so that the coating does not need to be arranged at the bonding position of the bipolar plate 1 and the porous transport layer 2, thereby reducing the coating area and saving the coating cost.

[0042] The bipolar plate structure 10 can be applied to an electrolytic cell, and the bipolar plate 1 and the porous transport layer 2 are connected into an integrated structure, which is beneficial to improving the mass transfer and heat transfer performance in the electrolytic cell.

[0043] In some embodiments, the integrated structure formed by the bipolar plate 1 and the porous transport layer 2 is provided with a coating on the entire outer surface.

[0044] Specifically, the bipolar plate 1 further has a first circumferential connecting surface, and the first main surface 11 and the second main surface 12 are connected through the first circumferential connecting surface. The porous transport layer 2 has a second circumferential connecting surface, and the transport layer first side surface 21 and the transport layer second side surface 22 are connected through the second circumferential connecting surface. The second main surface 12, the region of the first main surface 11 which is not covered by the porous transport layer 2, the transport layer second side surface 22 of the porous transport layer 2, and the first circumferential connecting surface and the second circumferential connecting surface are provided with a coating. In this way, the entire outer surface of the bipolar plate structure 10 is covered by the coating, so that the oxidation resistance of the bipolar plate structure 10 as a whole is improved.

[0045] In some embodiments, the porous transport layer 2 is fixedly connected to the bipolar plate 1 by welding. Specifically, the porous transport layer 2 is fixedly connected to the bipolar plate 1 by diffusion welding. The porous transport layer 2 is firmly welded to the bipolar plate 1, and the two are not easy to separate from each other. Diffusion welding is a connection technology, which can connect the porous transport layer 2 and the bipolar plate 1 together under high temperature and pressure. Diffusion welding realizes the combination between the porous transport layer 2 and the bipolar plate 1 through the mechanism of atomic diffusion.

[0046] In some embodiments, the first main surface 11 and / or the second main surface 12 is provided with a flow channel, and the surface roughness Ra of the flow channel is less than 5 μm. For example, the surface roughness Ra of the flow channel can be 0.8 μm, 1.6 μm, 2.3 μm, 3.2 μm, 4.8 μm, etc. The surface roughness Ra of the flow channel can also be other values less than 5 μm, which are not listed here.

[0047] In some embodiments, the first main surface 11 is provided with a flow channel, and the surface roughness Ra of the flow channel is less than 5 μm. By setting the surface roughness Ra of the flow channel on the first main surface 11 to be less than 5 μm, it can be ensured that the porous transport layer 2 and the bipolar plate 1 are firmly connected after welding, and the porous transport layer 2 and the bipolar plate 1 are not easy to separate, thereby improving the use reliability of the bipolar plate structure 10.

[0048] In some embodiments, the second major surface 12 is provided with flow channels, and the surface roughness Ra of the flow channels is less than 5 μm.

[0049] In some embodiments, the first major surface 11 and the second major surface 12 are both provided with flow channels, and the surface roughness Ra of the flow channels is less than 5 μm.

[0050] In some embodiments, the surface flow channels of the bipolar plate 1 can be processed by etching.

[0051] In some embodiments, the porous transport layer 2 comprises one or more of a porous titanium plate, a titanium fiber felt, and a titanium mesh. For example, the porous transport layer 2 is a porous titanium plate; for example, the porous transport layer 2 is a titanium fiber felt; for example, the porous transport layer 2 is a titanium mesh; for example, the porous transport layer 2 is a combination of a titanium fiber felt and a titanium mesh; for example, the porous transport layer 2 is a combination of a porous titanium plate and a titanium mesh; for example, the porous transport layer 2 is a combination of a porous titanium plate and a titanium fiber felt; for example, the porous transport layer 2 is a combination of a porous titanium plate, a titanium fiber felt, and a titanium mesh.

[0052] In some embodiments, the porous transport layer 2 comprises a porous titanium plate, and the porous titanium plate is a three-dimensional porous titanium plate or a two-dimensional porous titanium plate. For example, the porous transport layer 2 is a combination of a three-dimensional porous titanium plate and a titanium mesh; for example, the porous transport layer 2 is a combination of a two-dimensional porous titanium plate and a titanium mesh. For example, the porous transport layer 2 is a combination of a three-dimensional porous titanium plate and a titanium fiber felt; for example, the porous transport layer 2 is a combination of a two-dimensional porous titanium plate and a titanium fiber felt. For example, the porous transport layer 2 is a combination of a three-dimensional porous titanium plate, a titanium fiber felt, and a titanium mesh; for example, the porous transport layer 2 is a combination of a two-dimensional porous titanium plate, a titanium fiber felt, and a titanium mesh.

[0053] In some embodiments, the porous titanium plate is a three-dimensional porous titanium plate, and the three-dimensional porous titanium plate has first holes in the interior, and the first holes are open and connected, and the first holes can be used to provide the functions of conducting electrons, water flow channels, and catalyst carriers.

[0054] In some embodiments, the thickness of the three-dimensional porous titanium plate ranges from 0.3 mm to 2 mm. For example, the thickness of the three-dimensional porous titanium plate can be 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc., and can also be other values between 0.3 mm and 2 mm, which are not listed here.

[0055] When the thickness of the three-dimensional porous titanium plate is less than 0.3 mm, the three-dimensional porous titanium plate is prone to breakage and damage when connected to the bipolar plate 1. When the thickness of the three-dimensional porous titanium plate is greater than 2 mm, the thickness of the three-dimensional porous titanium plate is relatively large, which affects the conduction efficiency of electrons and the transmission efficiency of media. By setting the thickness of the three-dimensional porous titanium plate to range from 0.3 mm to 2 mm, the three-dimensional porous titanium plate is not prone to breakage and damage when connected to the bipolar plate 1, and has relatively high conduction efficiency of electrons and transmission efficiency of media.

[0056] In some embodiments, the porosity of the three-dimensional porous titanium plate ranges from 25% to 50%. For example, the porosity of the three-dimensional porous titanium plate can be 25%, 30%, 35%, 40%, 45%, 50%, etc., and can also be other values between 25% and 50%, which are not listed one by one here.

[0057] When the porosity of the three-dimensional porous titanium plate is less than 25%, the conduction efficiency of electrons, the transmission efficiency of media, and the amount of catalyst carried are affected. When the porosity of the three-dimensional porous titanium plate is greater than 50%, the strength of the three-dimensional porous titanium plate is low and is easy to be damaged. By setting the porosity of the three-dimensional porous titanium plate to range from 25% to 50%, the conduction efficiency of electrons, the transmission efficiency of media, and the amount of catalyst carried are high, and the strength of the three-dimensional porous titanium plate is high and is not easy to be damaged.

[0058] In some embodiments, the pore size of the first hole ranges from 10 μm to 100 μm. For example, the pore size of the first hole can be 10 μm, 30 μm, 50 μm, 70 μm, 90 μm, 100 μm, etc., and can also be other values between 10 μm and 100 μm, which are not listed one by one here.

[0059] When the pore size of the first hole is less than 10 μm, the conduction efficiency of electrons, the transmission efficiency of media, and the amount of catalyst carried are affected. When the pore size of the first hole is greater than 100 μm, the strength of the three-dimensional porous titanium plate is low and is easy to be damaged. By setting the pore size of the first hole to range from 10 μm to 100 μm, the conduction efficiency of electrons, the transmission efficiency of media, and the amount of catalyst carried are high, and the strength of the three-dimensional porous titanium plate is high and is not easy to be damaged.

[0060] In some embodiments, the porous titanium plate is a two-dimensional porous titanium plate, and the two-dimensional porous titanium plate is provided with a second hole. The second hole can be used to provide the functions of conducting electrons, water flow channels, and catalyst carriers, etc. The two-dimensional porous titanium plate refers to a titanium plate having a porous structure in two dimensions.

[0061] In some embodiments, the thickness of the two-dimensional porous titanium plate ranges from 0.1 mm to 1 mm. For example, the thickness of the two-dimensional porous titanium plate can be 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, etc., and can also be other values between 0.1 mm and 1 mm, which are not listed one by one here.

[0062] When the thickness of the two-dimensional porous titanium plate is less than 0.1 mm, the two-dimensional porous titanium plate is prone to breakage and damage when connected with the bipolar plate 1. When the thickness of the two-dimensional porous titanium plate is greater than 1 mm, the thickness of the two-dimensional porous titanium plate is large, affecting the conduction efficiency of electrons and the transmission efficiency of media. By setting the thickness of the two-dimensional porous titanium plate to be 0.1 mm to 1 mm, the two-dimensional porous titanium plate is not prone to breakage and damage when connected with the bipolar plate 1, and has high conduction efficiency of electrons and high transmission efficiency of media.

[0063] In some embodiments, the second hole has a pore size ranging from 0.1 mm to 0.5 mm. For example, the second hole can have a pore size of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc., and can also have other values between 0.1 mm and 0.5 mm, which will not be listed one by one here.

[0064] When the pore size of the second hole is less than 0.1 mm, the conduction efficiency of electrons and the transmission efficiency of media are affected, and the catalyst carried is also less. When the pore size of the second hole is greater than 0.5 mm, the strength of the two-dimensional porous titanium plate is low and is prone to damage. By setting the pore size of the second hole to be 0.1 mm to 0.5 mm, the two-dimensional porous titanium plate has high conduction efficiency of electrons, high transmission efficiency of media, and carries more catalyst, and has high strength and is not prone to damage.

[0065] In some embodiments, the titanium fiber felt has a third hole inside, which can be used to provide the functions of conducting electrons, water flow channels, and catalyst carriers, etc. In some embodiments, the thickness of the titanium fiber felt ranges from 0.15 mm to 2 mm. For example, the thickness of the titanium fiber felt can be 0.15 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.3 mm, 1.6 mm, 2 mm, etc., and can also have other values between 0.15 mm and 2 mm, which will not be listed one by one here.

[0066] When the thickness of the titanium fiber felt is less than 0.15 mm, the titanium fiber felt is prone to breakage and damage when connected with the bipolar plate 1. When the thickness of the titanium fiber felt is greater than 2 mm, the thickness of the titanium fiber felt is large, affecting the conduction efficiency of electrons and the transmission efficiency of media. By setting the thickness of the titanium fiber felt to be 0.15 mm to 2 mm, the titanium fiber felt is not prone to breakage and damage when connected with the bipolar plate 1, and has high conduction efficiency of electrons and high transmission efficiency of media.

[0067] In some embodiments, the porosity of the titanium fiber felt ranges from 50% to 80%. For example, the porosity of the titanium fiber felt can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc., and can also have other values between 50% and 80%, which will not be listed one by one here.

[0068] When the porosity of the titanium fiber felt is less than 50%, the conduction efficiency of the electron, the transmission efficiency of the medium, and the supported catalyst are less. When the porosity of the titanium fiber felt is greater than 80%, the strength of the titanium fiber felt is low and is easy to be damaged. By setting the porosity of the titanium fiber felt to be 50% to 80%, the conduction efficiency of the electron, the transmission efficiency of the medium, and the supported catalyst are high, and the strength of the titanium fiber felt is high and is not easy to be damaged.

[0069] In some embodiments, the third hole has a pore size ranging from 10 μm to 50 μm. For example, the third hole can have a pore size of 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, or the like, and can also have other values between 10 μm and 50 μm, which are not listed one by one here.

[0070] When the pore size of the third hole is less than 10 μm, the conduction efficiency of the electron, the transmission efficiency of the medium, and the supported catalyst are less. When the pore size of the third hole is greater than 50 μm, the strength of the titanium fiber felt is low and is easy to be damaged. By setting the pore size of the third hole to be 10 μm to 50 μm, the conduction efficiency of the electron, the transmission efficiency of the medium, and the supported catalyst are high, and the strength of the titanium fiber felt is high and is not easy to be damaged.

[0071] In some embodiments, the titanium mesh includes a woven titanium mesh and / or a diamond-shaped stretched titanium mesh. For example, the titanium mesh is a woven titanium mesh; for another example, the titanium mesh is a diamond-shaped stretched titanium mesh; for another example, the titanium mesh is a combination of a woven titanium mesh and a diamond-shaped stretched titanium mesh.

[0072] In some embodiments, the thickness of the titanium mesh ranges from 0.3 mm to 5 mm. For example, the thickness of the titanium mesh can be 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or the like, and can also be other values between 0.3 mm and 5 mm, which are not listed one by one here.

[0073] When the thickness of the titanium mesh is less than 0.3 mm, the titanium mesh is easy to be broken and damaged when connected with the bipolar plate 1. When the thickness of the titanium mesh is greater than 5 mm, the thickness of the titanium mesh is large, which affects the conduction efficiency of the electron and the transmission efficiency of the medium. By setting the thickness of the titanium mesh to be 0.3 mm to 5 mm, the titanium mesh is not easy to be broken and damaged when connected with the bipolar plate 1, and the conduction efficiency of the electron and the transmission efficiency of the medium are high.

[0074] In some embodiments, the titanium mesh has a mesh number ranging from 30 mesh to 200 mesh. For example, the titanium mesh can have a mesh number of 30 mesh, 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh, or any other value within the range of 30 mesh to 200 mesh, which will not be listed one by one here.

[0075] In some embodiments, the titanium mesh has a wire diameter ranging from 0.2 mm to 0.5 mm. For example, the titanium mesh can have a wire diameter of 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, or any other value within the range of 0.2 mm to 0.5 mm, which will not be listed one by one here.

[0076] When the wire diameter of the titanium mesh is less than 0.2 mm, the titanium mesh is prone to breakage and damage. When the wire diameter of the titanium mesh is greater than 0.5 mm, the titanium mesh is relatively thick, resulting in material waste, a smaller mesh number of the titanium mesh, and affecting the conduction efficiency of electrons, the transmission efficiency of the medium, and the catalyst carried by the titanium mesh. By setting the wire diameter of the titanium mesh to range from 0.2 mm to 0.5 mm, the titanium mesh is moderately thick, the titanium mesh is not prone to breakage and damage, and the mesh number of the titanium mesh can also be set to be relatively appropriate, so that the titanium mesh has a relatively high conduction efficiency of electrons, a relatively high transmission efficiency of the medium, and carries a relatively large amount of catalyst.

[0077] In some embodiments, the porous transmission layer 2 is a pure titanium layer.

[0078] In some embodiments, the porous transmission layer 2 is a titanium-palladium alloy layer.

[0079] In some embodiments, the bipolar plate 1 is a pure titanium plate.

[0080] In some embodiments, the bipolar plate 1 is a titanium-aluminum-vanadium alloy plate.

[0081] In some embodiments, the bipolar plate 1 is a titanium-palladium alloy plate.

[0082] In some embodiments, the bipolar plate 1 is a stainless steel plate.

[0083] In some embodiments, during the processing of the bipolar plate structure 10, the porous transmission layer 2 and the bipolar plate 1 are first placed in a processing device, which can be a vacuum heating furnace. When the vacuum degree in the processing device reaches a preset vacuum value, the porous transmission layer 2 and the bipolar plate 1 are heated, the heating temperature is 800°C to 1100°C, the porous transmission layer 2 and the bipolar plate 1 are pressed tightly, the pressing force applied to the porous transmission layer 2 and the bipolar plate 1 is 1.5 MPa to 4 MPa, and the heating time is 1 hour to 5 hours (i.e., 1 h to 5 h). By selecting such processing parameters, the porous transmission layer 2 can be prevented from being welded into a dense plate during welding, and the welded porous transmission layer 2 and the bipolar plate 1 still meet the mass transfer requirements of the electrolytic cell.

[0084] The preset vacuum value can be 6x10 -3 Pa, 5x10 -3 Pa, or other values.

[0085] In the process of the bipolar plate structure 10, before the porous transport layer 2 and the bipolar plate 1 are heated, the pressing force applied to the porous transport layer 2 and the bipolar plate 1 is 0.5 MPa, and when the vacuum degree in the processing equipment reaches 6x10 -3 Pa, the porous transport layer 2 and the bipolar plate 1 are heated, and the pressing force is increased to the welding pressure, i.e. 1.5 MPa-4 MPa.

[0086] In the process of the bipolar plate structure 10, in order to improve the processing efficiency, multiple bipolar plates 1 and multiple porous transport layers 2 are welded together in each batch, and graphite plates are used to separate each group of bipolar plates 1 and porous transport layers 2. The area of the graphite plate is greater than that of the bipolar plate 1, and the thickness of the graphite plate is 10 mm-50 mm, for example, the thickness of the graphite plate can be 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, or other thickness values between 10 mm and 50 mm.

[0087] The following describes nine specific embodiments of the bipolar plate structure 10 of the present application processed using the above-mentioned temperature, pressing force, heating time, etc.

[0088] Example 1:

[0089] 1. The bipolar plate 1 and a 1 mm thick three-dimensional porous titanium plate are used as the welding base material, the surface roughness Ra of the bipolar plate 1 is 2.3 μm, and the bipolar plate 1 and the three-dimensional porous titanium plate are cleaned in pure water and then dried;

[0090] 2. The bipolar plate 1 and the three-dimensional porous titanium plate are placed in contact, placed in a vacuum heating furnace, and a pressure of 0.5 MPa is applied. When the vacuum degree reaches 6x10 -3 Pa, heating is started, the heating rate is 15°C / min, the temperature is increased to 950°C, the pressing force is increased to 3 MPa, and after heating for 3 h, the temperature is decreased to 400°C at a cooling rate of 10°C / min, and then the furnace is cooled to room temperature;

[0091] 3. A 1 μm platinum layer is electroplated on the surface of the bipolar plate structure 10 using an electroplating process, and a PEM electrolytic cell is assembled for testing, and the test temperature is 60°C.

[0092] Example 2:

[0093] 1. The bipolar plate 1 and a 0.25 mm thick titanium fiber felt are used as the welding base material, the surface roughness Ra of the bipolar plate 1 is 2.3 μm, and the bipolar plate 1 and the titanium fiber felt are cleaned in pure water and then dried;

[0094] 2. Put the bipolar plate 1 in contact with the titanium fiber felt to be welded, place it in a vacuum heating furnace, and apply a pressure of 0.5 MPa. When the vacuum degree reaches 6 x 10 -3 Pa, start heating, heat to 850°C at a heating rate of 15°C / min, increase the pressing force to 1.5 MPa, heat for 1 h, then cool to 400°C at a cooling rate of 10°C / min, and then cool to room temperature with the furnace;

[0095] 3. Use electroplating process to electroplate 1 μm platinum on the surface of the bipolar plate structure 10, assemble a PEM electrolytic cell for testing, and the testing temperature is 60°C.

[0096] Example 3:

[0097] 1. Use the bipolar plate 1 and 0.4 mm thick titanium fiber felt as the welding base material, and the surface roughness Ra of the bipolar plate 1 is 2.3 μm. Clean the bipolar plate 1 and the titanium fiber felt in pure water and dry them;

[0098] 2. Put the bipolar plate 1 in contact with the titanium fiber felt to be welded, place it in a vacuum heating furnace, and apply a pressure of 0.5 MPa. When the vacuum degree reaches 6 x 10 -3 Pa, start heating, heat to 900°C at a heating rate of 15°C / min, increase the pressing force to 2 MPa, heat for 2 h, then cool to 400°C at a cooling rate of 10°C / min, and then cool to room temperature with the furnace;

[0099] 3. Use electroplating process to electroplate 1 μm platinum on the surface of the bipolar plate structure 10, assemble a PEM electrolytic cell for testing, and the testing temperature is 60°C.

[0100] Example 4:

[0101] 1. Use the bipolar plate 1, 0.25 mm thick titanium fiber felt, and 0.8 mm thick 150 mesh diamond-shaped tensile titanium mesh as the welding base material, and the surface roughness Ra of the bipolar plate 1 is 2.3 μm. Clean the bipolar plate 1, the titanium fiber felt, and the titanium mesh in pure water and dry them;

[0102] 2. Put the bipolar plate 1 in contact with the titanium fiber felt to be welded, place it in a vacuum heating furnace, and apply a pressure of 0.5 MPa. When the vacuum degree reaches 6 x 10 -3 Pa, start heating, heat to 890°C at a heating rate of 15°C / min, increase the pressing force to 1.5 MPa, heat for 1.5 h, then cool to 400°C at a cooling rate of 10°C / min, and then cool to room temperature with the furnace;

[0103] 3. Use electroplating process to electroplate 1 μm platinum on the surface of the bipolar plate structure 10, assemble a PEM electrolytic cell for testing, and the testing temperature is 60°C.

[0104] Example 5:

[0105] 1. The bipolar plate 1, 0.25 mm thick titanium fiber felt, 2 titanium mesh 0.4 mm thick braided titanium mesh as the welding base material, 2 titanium mesh between the bipolar plate 1 and the titanium fiber felt, wherein the 2 titanium mesh aperture is 80 mesh and 200 mesh respectively, the 80 mesh titanium mesh is close to the bipolar plate 1, and the 200 mesh titanium mesh is close to the titanium fiber felt. The surface roughness Ra of the flow channel of the bipolar plate 1 is 2.3 μm, and the bipolar plate 1, titanium fiber felt and titanium mesh are placed in pure water and dried after cleaning;

[0106] 2. The bipolar plate 1-80 mesh titanium mesh-200 mesh titanium mesh-titanium fiber felt to be welded is placed in contact, placed in a vacuum heating furnace, and a pressure of 0.5 MPa is applied. When the vacuum degree reaches 6x10 -3 Pa, start heating, heat to 890℃ at a heating rate of 15℃ / min, increase the pressure to 1.5 MPa, heat for 3h, then cool to 400℃ at a cooling rate of 10℃ / min, and then cool to room temperature with the furnace;

[0107] 3. Electroplating process is used to electroplate 1 μm platinum on the surface of the bipolar plate structure 10, and a PEM electrolytic cell is assembled for testing, and the test temperature is 60℃.

[0108] Example 6:

[0109] 1. The bipolar plate 1, 0.4 mm thick titanium fiber felt, 0.4 mm thick 100 mesh braided titanium mesh as the welding base material, the surface roughness Ra of the flow channel of the bipolar plate 1 is 2.3 μm, and the bipolar plate 1, titanium fiber felt and titanium mesh are placed in pure water and dried after cleaning;

[0110] 2. The bipolar plate 1-titanium mesh-titanium fiber felt to be welded is placed in contact, placed in a vacuum heating furnace, and a pressure of 0.5 MPa is applied. When the vacuum degree reaches 6x10 -3 Pa, start heating, heat to 900℃ at a heating rate of 15℃ / min, increase the pressure to 2 MPa, heat for 3h, then cool to 400℃ at a cooling rate of 10℃ / min, and then cool to room temperature with the furnace;

[0111] 3. Electroplating process is used to electroplate 1 μm platinum on the surface of the bipolar plate structure 10, and a PEM electrolytic cell is assembled for testing, and the test temperature is 60℃.

[0112] Example 7:

[0113] 1. The bipolar plate 1, 1 mm thick three-dimensional porous titanium plate, 0.5 mm thick 50 mesh braided titanium mesh as the welding base material, the surface roughness Ra of the flow channel of the bipolar plate 1 is 2.3 μm, and the bipolar plate 1, titanium fiber felt and titanium mesh are placed in pure water and dried after cleaning;

[0114] 2. The bipolar plate 1-titanium mesh-three-dimensional porous titanium plate to be welded surface contact is placed in a vacuum heating furnace, and a pressure of 0.5 MPa is applied. When the vacuum degree reaches 6x10 -3 Pa, heating is started. The heating rate is 15 ℃ / min to 950 ℃. The pressure is increased to 3 MPa. After heating for 3 h, the cooling rate is 10 ℃ / min to 400 ℃. Then, the furnace is cooled to room temperature.

[0115] 3. The surface of the bipolar plate structure 10 is plated with 1 μm of platinum by electroplating process. The PEM electrolytic cell is assembled for testing. The testing temperature is 60 ℃.

[0116] Example 8:

[0117] 1. The bipolar plate 1, 0.4 mm thick titanium fiber felt, and 0.25 mm thick titanium fiber felt are used as the welding base material. The 0.4 mm thick titanium fiber felt is close to the bipolar plate 1, and the 0.25 mm thick titanium fiber felt is close to the catalytic layer. The surface roughness Ra of the bipolar plate 1 is 2.3 μm. The bipolar plate 1, titanium fiber felt, and titanium mesh are cleaned in pure water and then dried.

[0118] 2. The bipolar plate 1-0.4 mm thick titanium fiber felt-0.25 mm thick titanium fiber felt to be welded surface is placed in contact. It is placed in a vacuum heating furnace and a pressure of 0.5 MPa is applied. When the vacuum degree reaches 6x10 -3 Pa, heating is started. The heating rate is 15 ℃ / min to 850 ℃. The pressure is increased to 1.5 MPa. After heating for 3 h, the cooling rate is 10 ℃ / min to 400 ℃. Then, the furnace is cooled to room temperature.

[0119] 3. The surface of the bipolar plate structure 10 is plated with 1 μm of platinum by electroplating process. The PEM electrolytic cell is assembled for testing. The testing temperature is 60 ℃.

[0120] Example 9:

[0121] 1. The bipolar plate 1, 0.2 mm thick two-dimensional porous titanium plate, and two 0.4 mm thick woven titanium meshes are used as the welding base material. The surface roughness Ra of the bipolar plate 1 is 2.3 μm. The bipolar plate 1, titanium fiber felt, and titanium mesh are cleaned in pure water and then dried.

[0122] 2. The bipolar plate 1-titanium mesh-titanium fiber felt to be welded surface is placed in contact. It is placed in a vacuum heating furnace and a pressure of 0.5 MPa is applied. When the vacuum degree reaches 6x10 -3 Pa, heating is started. The heating rate is 15 ℃ / min to 1050 ℃. The pressure is increased to 4 MPa. After heating for 4 h, the cooling rate is 10 ℃ / min to 400 ℃. Then, the furnace is cooled to room temperature.

[0123] 3. The surface of the bipolar plate structure 10 is plated with 1 μm platinum by electroplating process, and the PEM electrolyzer is assembled and tested at a temperature of 60℃.

[0124] The bipolar plate 1 and the porous transport layer 2 are not fixed in the comparative example 1, which is specifically that the bipolar plate and the 0.4 mm thick titanium fiber felt are used, the surface is plated with 1 μm platinum by electroplating process, and the PEM electrolyzer is assembled and tested at a temperature of 60℃.

[0125] The bipolar plate structure 10 of the present application is not processed by using the above processing parameters such as temperature, pressing force, heating time, etc. in the comparative example 2, which is specifically that:

[0126] 1. The bipolar plate 1 and the 0.4 mm thick titanium fiber felt are used as the welding base material, the surface roughness Ra of the bipolar plate 1 is 2.3 μm, and the bipolar plate 1 and the titanium fiber felt are placed in pure water and dried after cleaning;

[0127] 2. The welding surfaces of the bipolar plate 1 and the titanium fiber felt are placed in contact, placed in a vacuum heating furnace, and a pressure of 0.5 MPa is applied. When the vacuum degree reaches 6×10 -3 Pa, heating is started, the heating rate is 15℃ / min to 800℃, the pressing force is increased to 1 MPa, and after heating for 2 h, the cooling rate is 10℃ / min to 400℃, and then the furnace is cooled to room temperature;

[0128] 3. The surface is plated with 1 μm platinum by electroplating process, and the PEM electrolyzer is assembled and tested at a temperature of 60℃.

[0129] That is, the pressing force in the comparative example 2 is not within the parameter range of 1.5 MPa to 4 MPa. The lower pressing force in the comparative example 2 can cause the bipolar plate 1 and the porous transport layer 2 to fail to be effectively welded as a whole, affect the subsequent electroplating process, and result in poor electrolysis performance.

[0130] The bipolar plate structure 10 of the comparative example 1 and the products obtained in the comparative examples 2 are placed in the electrolyzer for use. It can be seen that the performance of the bipolar plate structure 10 of the comparative example 1 and the products obtained in the comparative examples 2 is similar, and can meet the mass transfer requirements of the electrolyzer, while the products obtained in the comparative example 2 cannot meet the mass transfer requirements.

[0131] The electrolyzer according to the second aspect of the present application includes the bipolar plate structure 10 of the above-mentioned embodiments. Specifically, the electrolyzer is a PEM electrolyzer.

[0132] One side of the first main surface 11 and the second main surface 12 is an anode side, and the other side is a cathode side. Referring to Figure 4In the electrolytic cell, the bipolar plate structure 10 and the membrane electrode 3 are arranged alternately, and the bipolar plate structure 10 and the membrane electrode 3 can be arranged alternately for multiple times (for example, hundreds of times) to meet the demand of hydrogen production by electrolysis of water.

[0133] According to the electrolytic cell of the embodiment of the present application, the bipolar plate structure 10 is fixed on the first main surface 11 by the porous transport layer 2, so that the coating is not necessarily arranged at the bonding position of the bipolar plate 1 and the porous transport layer 2, thereby reducing the coating area and saving the coating cost, and further saving the cost of the electrolytic cell.

[0134] According to the hydrogen production system of the third aspect of the embodiment of the present application, the electrolytic cell includes the above-mentioned embodiment.

[0135] According to the hydrogen production system of the embodiment of the present application, the bipolar plate structure 10 of the electrolytic cell is fixed on the first main surface 11 by the porous transport layer 2, so that the coating is not necessarily arranged at the bonding position of the bipolar plate 1 and the porous transport layer 2, thereby reducing the coating area and saving the coating cost, and further saving the cost of the electrolytic cell and the hydrogen production system.

[0136] In the description of the present application, it should be understood that the term “thickness” is the size in the up-down direction as shown in the drawings. Figure 3 and Figure 4 The size in the up-down direction as shown in the drawings.

[0137] In the present application, unless specifically defined and limited otherwise, the terms “mounting”, “connection”, “connecting”, “fixed”, and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or can be integrated; can be mechanical connection, can also be electrical connection or can communicate with each other; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0138] In the description of the present application, the description of the terms “one embodiment”, “some embodiments”, “example”, “specific example” or “some examples” means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application.

[0139] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A bipolar plate structure (10) characterized by, The bipolar plate (1) has a first major surface (11) and a second major surface (12) arranged away from each other; The porous transport layer (2) is fixed on the first major surface (11) and forms an integral structure with the bipolar plate (1); A coating is arranged on the surface of the second major surface (12) and the porous transport layer (2) away from the bipolar plate (1); The porous transport layer (2) is fixedly connected with the bipolar plate (1) by diffusion welding. The first major surface (11) and / or the second major surface (12) of the bipolar plate is provided with a flow channel, and the surface roughness Ra of the flow channel is less than 5 μm.

2. The bipolar plate structure (10) according to claim 1, characterized in that The porous transport layer (2) comprises one or more of a porous titanium plate, a titanium fiber felt, and a titanium mesh.

3. The bipolar plate structure (10) according to claim 1, characterized in that The porous transport layer (2) comprises a porous titanium plate, and the porous titanium plate is a three-dimensional porous titanium plate or a two-dimensional porous titanium plate.

4. The bipolar plate structure (10) according to claim 3, characterized in that The three-dimensional porous titanium plate has a first hole in the interior thereof; 5. The bipolar plate structure (10) according to claim 4, characterized in that The thickness of the three-dimensional porous titanium plate ranges from 0.3 mm to 2 mm, and / or the porosity of the three-dimensional porous titanium plate ranges from 25% to 50%, and / or the pore size of the first hole ranges from 10 μm to 100 μm. The two-dimensional porous titanium plate is provided with a second hole; 6. The bipolar plate structure (10) according to claim 4, characterized in that The thickness of the two-dimensional porous titanium plate ranges from 0.1 mm to 1 mm, and / or the pore size of the second hole ranges from 0.1 mm to 0.5 mm. The titanium fiber felt has a third hole in the interior thereof; 7. The bipolar plate structure (10) according to claim 3, characterized in that The thickness of the titanium fiber felt ranges from 0.15 mm to 2 mm, and / or the porosity of the titanium fiber felt ranges from 50% to 80%, and / or the pore size of the third hole ranges from 10 μm to 50 μm. The titanium mesh comprises a woven titanium mesh and / or a diamond-shaped stretched titanium mesh; 8. The bipolar plate structure (10) according to claim 3, characterized in that The thickness of the titanium mesh ranges from 0.3 mm to 5 mm, and / or the mesh number of the titanium mesh ranges from 30 to 200, and / or the wire diameter of the titanium mesh ranges from 0.2 mm to 0.5 mm. The integral structure is provided with a coating on all external surfaces thereof.

9. The bipolar plate structure (10) according to claim 1, characterized in that The bipolar plate structure (10) according to any one of claims 1 to 9.

10. An electrolytic cell characterized in that, The electrolytic cell according to claim 10.

11. A hydrogen production system, characterized by, ​

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