Bipolar plate assembly and modular electrolytic cell

Abstract

The invention discloses a bipolar plate assembly and a modular electrolytic cell. The bipolar plate assembly comprises a partition plate, two side surfaces of which are respectively and completely symmetrically provided with porous transmission layers; each porous transmission layer is formed by welding a plurality of layers of metal expansion nets with different porosities; the closer the metal expansion nets are to the partition plate, the higher the porosity is, and the farther the metal expansion nets are away from the partition plate, the lower the porosity is; and the two rubber sealing frames are respectively fixed around the partition plate and the porous transmission layer from two sides, so that the partition plate and the porous transmission layer are integrated. According to the bipolar plate assembly disclosed by the invention, the transmission efficiency of gas generated by electrolysis is improved by arranging the expansion net with the gradient porous structure and the aperture.

Description

Technical Field

[0001] The present invention relates to the technical field of water electrolyzers, and more specifically, to a bipolar plate assembly and a modular electrolyzer. Background Art

[0002] As a fuel, hydrogen has the characteristics of concentrated flame, high calorific value, high efficiency, etc., and can be combined with other energy sources to make fuller use of energy. It is produced from water, and the combustion product is still reduced to water. The whole process will not cause pollution to the environment. Therefore, hydrogen energy is an extremely superior secondary energy source and the cleanest and most efficient new energy source in the 21st century. At present, the technology of using electrolysis equipment to electrolyze water to produce hydrogen has received widespread attention and recognition.

[0003] In a water electrolyzer, the electrolytic stack is an important component, especially the bipolar plate assembly, which is an important component of the electrolytic stack. The bipolar plate assembly commonly used at present is composed of a bipolar plate body, a polar mesh and a seal connected in sequence. The bipolar plate body is a monolithic anode flow field and a monolithic cathode flow field arranged on both sides along the thickness direction. The anode flow field is made of stainless steel or alkali-resistant and high-temperature resistant plastic, and the cathode flow field is made of stainless steel or alkali-resistant and high-temperature resistant plastic. However, the gas transmission efficiency between this monolithic anode flow field and cathode flow field is low. The gas generated by electrolysis accumulates near the flow field and cannot be quickly discharged by the electrode, which will interfere with the decomposition of the remaining electrolyte and reduce the decomposition efficiency. Summary of the invention

[0004] The present invention provides a bipolar plate assembly, which aims to solve the problem that the existing bipolar plate structure cannot discharge the electrolyzed gas out of the electrolytic cell in time, and improve the output efficiency of the gas in the electrolytic cell.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: A bipolar plate assembly comprises: a separator plate, on both sides of which porous transmission layers are arranged completely symmetrically; each of the porous transmission layers is welded from multiple layers of expanded metal meshes with different porosities; the closer the expanded metal meshes are to the separator plate, the higher the porosity, while the farther the expanded metal meshes are from the separator plate, the lower the porosity; two rubber sealing frames are fixed around the separator plate and the porous transmission layer from both sides to integrate them.

[0006] Preferably, the porosity of the expanded metal mesh farthest from the partition plate is 50%, and the porosity of the expanded metal mesh closest to the partition plate is 75%.

[0007] Preferably, a hook is extended outward from each of the two ends of the partition plate, and a socket of a voltage detection terminal protruding upward is formed on the hook.

[0008] Preferably, a gradient flow guide section is provided at the inlet and outlet of the electrolyte and the gas on the rubber sealing frame.

[0009] Preferably, the rubber sealing frame is made of ethylene propylene diene rubber.

[0010] The bipolar plate assembly of the present invention improves the transmission efficiency of the gas generated by electrolysis by setting the expanded mesh and pore size of the gradient porous structure.

[0011] The present application also proposes a modular electrolyzer, comprising a press and an anion membrane water electrolyzer, wherein: the press comprises: A machine base, on which a front fixing plate and a rear fixing plate are provided; a fixing screw, which is passed through the front fixing plate and the rear fixing plate; a pressure regulating mechanism, which includes an adjusting screw, a pushing plate and a pressure sensor, the pushing plate is passed through the fixing screw, the adjusting screw is fixed on the front fixing plate and the end of the adjusting screw is connected to the pushing plate, and the pushing plate is driven forward or backward by the rotation of the adjusting screw to adjust the pressure; the anion membrane water electrolyzer is arranged between the pressure regulating mechanism and the rear fixing plate; the anion membrane water electrolyzer includes a cathode end plate, a cathode current collecting plate, an electrolysis main assembly, an anode current collecting plate and an anode collecting end plate fixed together in sequence by multiple groups of bolts; the electrolysis main assembly includes a plurality of membrane electrodes and bipolar plate assemblies stacked in sequence, wherein: the bipolar plate assembly is as described above.

[0012] Preferably, the membrane electrode is formed by stacking a cathode electrode, a sealing frame, an anion membrane, a sealing frame, and an anode electrode in sequence.

[0013] Preferably, the cathode electrode comprises a first conductive substrate layer in the form of a plain mesh with 100 mesh openings woven from nickel wire, a nickel-molybdenum catalyst is coated on the surface of the first conductive substrate layer, and the porosity of the first conductive substrate layer is 50%.

[0014] Preferably, the anode electrode comprises a second conductive substrate layer of a plain mesh with 100 mesh openings woven from nickel wires, Raney nickel particles are sprayed on the surface of the second conductive substrate layer, and the porosity of the second conductive substrate layer is 50%.

[0015] The modular electrolyzer of the present invention realizes pressure regulation of the anion membrane water electrolyzer through a press to prevent overpressure from causing the temperature of the bipolar plate assembly to be too high. At the same time, the adjustment of the press can realize the adjustment of the number of electrolysis main components in the anion membrane water electrolyzer and the replacement and maintenance of components. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall structure of the bipolar plate assembly of the present invention; Figure 2 is an exploded view of the bipolar plate assembly of the present invention; Figure 3 for Figure 1 AA section view; Figure 4 The overall structure of the modular electrolytic cell of the present invention is shown in FIG. Figure 1 ; Figure 5 The overall structure of the modular electrolytic cell of the present invention is schematically shown Figure 2 ; Figure 6 A schematic diagram of an embodiment of an electrolysis main component; Figure 7 This is an exploded view of an anion membrane water electrolyzer. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0018] See also Figure 1-Figure 3 As shown, the bipolar plate assembly of the present invention includes a separator plate 1, a porous transmission layer 2 and a rubber sealing frame 3.

[0019] The separator 1 is a nickel plate, which serves as a partition wall separating the anode porous transport layer and the cathode porous transport layer. Completely symmetrical porous transport layers 2 are respectively arranged on both sides of the separator 1 to form an anode flow field and a cathode flow field. A hook 11 is extended outward from both ends of the separator 1 to facilitate hanging on an external press machine, and a socket 12 of a voltage detection terminal protruding upward is formed on the hook 11 to facilitate connecting the voltage detection terminal to monitor the voltage of each electrolytic cell unit in the electrolytic cell.

[0020] Each porous transmission layer 2 adopts a gradient porosity design and is welded from multiple layers of expanded metal meshes with different porosities. The closer the expanded metal meshes of each layer are to the partition plate, the higher the porosity is, and the farther the expanded metal meshes are from the partition plate, the lower the porosity is. The porosity of the expanded metal mesh farthest from the partition plate is 50%, and the porosity of the expanded metal mesh closest to the partition plate is preferably 75%. The porosity of the porous transmission layer 2 is gradually increased with the generation and flow direction of gas, thereby improving the transmission efficiency of the electrolyte and gas. The gradient porosity design of the present invention provides excellent mass transmission for high current density operation due to its gradient porous structure expanded mesh and adapted pore size.

[0021] Two rubber sealing frames 3 are fixed around the partition plate 1 and the porous transmission layer 2 from both sides to make them integrated. The material of the rubber sealing frame is ethylene propylene diene rubber. It has the characteristics of anti-aging, acid and alkali resistance, low water absorption, long life, low cost, and wide operating temperature range. The rubber sealing frame 3 is made by molding, and a gradient guide section design 31 is adopted at the electrolyte and gas inlet and outlet to reduce fluid resistance and facilitate gas overflow speed.

[0022] In addition, combined Figure 4-Figure 5 As shown, the present invention also provides a modular electrolyzer, including a press and an anion membrane water electrolyzer 5 .

[0023] Wherein, the press comprises a machine base 41, on which a front fixing plate 411 and a rear fixing plate 412 are provided. The machine base 41 serves as the main supporting component. A plurality of fixing screws 42 are provided through the front fixing plate 411 and the rear fixing plate 412 to form an installation space and provide support for the anion membrane water electrolyzer 5. The hook 11 of the partition of the bipolar plate assembly is suspended on the fixing screw 42. The pressure regulating mechanism comprises an adjusting screw 431, a push plate 432 and a pressure sensor 433. The push plate 432 is provided through the fixing screw 42 and can move relative to the fixing screw 42. The adjusting screw 431 is fixed on the front fixing plate 411 and the end of the adjusting screw 431 is connected to the push plate 432, and the push plate 432 is driven forward or backward by the rotation of the adjusting screw 431 to adjust the pressure. The pressure sensor 433 is installed at the junction of the adjusting screw 431 and the push plate 432 to sense the pressure on the anion membrane water electrolyzer 5 and transmit it to a pressure display device.

[0024] The anionic membrane water electrolyzer 5 is arranged between the pressure regulating mechanism and the rear fixing plate 412. The anionic membrane water electrolyzer 5 comprises a cathode terminal plate 51, a cathode current collecting plate 52, an electrolysis main assembly 53, an anode current collecting plate 54 and an anode collecting end plate 55 which are fixed together in sequence by multiple groups of bolts. The electrolysis main assembly 53 comprises a plurality of membrane electrodes 531 and a bipolar plate assembly 532 which are stacked in sequence. The structure of the bipolar plate assembly 532 is as described above.

[0025] The membrane electrode 531 is composed of a cathode electrode, a sealing frame, an anion membrane, a sealing frame, and an anode electrode stacked in sequence. The cathode electrode includes a first conductive substrate layer with a 100-mesh opening plain mesh woven from nickel wire, and a nickel-molybdenum catalyst is coated on the surface of the first conductive substrate layer, and the porosity of the first conductive substrate layer is 50%. The anode electrode includes a second conductive substrate layer with a 100-mesh opening plain mesh woven from nickel wire, and Raney nickel particles are sprayed on the surface of the second conductive substrate layer, and the porosity of the second conductive substrate layer is 50%.

[0026] The modular electrolyzer of the present invention realizes pressure regulation of the anion membrane water electrolyzer through a press to prevent overpressure from causing the temperature of the bipolar plate assembly to be too high. At the same time, the adjustment of the press can realize the adjustment of the number of electrolysis main components in the anion membrane water electrolyzer and the replacement and maintenance of components.

[0027] The above-described embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Equivalent changes and modifications made to the present invention by those skilled in the art should all fall within the scope of the claims attached to the present invention.

Claims

1. A bipolar plate assembly, characterized in that: include: A partition plate, two sides of which are respectively and symmetrically provided with porous transmission layers; Each of the porous transmission layers is welded by multiple layers of expanded metal meshes with different porosities; the closer the expanded metal meshes are to the partition plate, the higher the porosity is, while the farther the expanded metal meshes are from the partition plate, the lower the porosity is; Two rubber sealing frames are respectively fixed around the partition plate and the porous transmission layer from two sides to make them integrated.

2. The bipolar plate assembly according to claim 1, characterized in that: The porosity of the expanded metal mesh farthest from the partition plate is 50%, and the porosity of the expanded metal mesh closest to the partition plate is 75%.

3. The bipolar plate assembly according to claim 1, characterized in that: A hook is extended outward from each of the two ends of the partition plate, and a socket of a voltage detection terminal protruding upward is formed on the hook.

4. The bipolar plate assembly according to claim 1, characterized in that: A gradient flow guide section is provided at the inlet and outlet of the electrolyte and the gas on the rubber sealing frame.

5. The bipolar plate assembly according to claim 1, characterized in that: The material of the rubber sealing frame is ethylene propylene diene rubber.

6. A modular electrolytic cell, characterized in that: It includes a press and an anion membrane water electrolyzer, wherein: The press comprises: A machine base, on which a front fixing plate and a rear fixing plate are provided; A fixing screw rod, which is passed through the front fixing plate and the rear fixing plate; The pressure regulating mechanism comprises an adjusting screw, a push plate and a pressure sensor, wherein the push plate is inserted into the fixing screw, the adjusting screw is fixed to the front fixing plate and the end of the adjusting screw is connected to the push plate, and the adjusting screw is rotated to drive the push plate forward or backward to adjust the pressure; The anion membrane water electrolyzer is arranged between the pressure regulating mechanism and the rear fixing plate; the anion membrane water electrolyzer comprises a cathode end plate, a cathode current collecting plate, an electrolysis main assembly, an anode current collecting plate and an anode collecting end plate which are fixed together in sequence by multiple groups of bolts; the electrolysis main assembly comprises a plurality of membrane electrodes and a bipolar plate assemblies which are stacked in sequence, wherein: the bipolar plate assembly is as described in any one of claims 1 to 5.

7. The anionic membrane water electrolyzer according to claim 6, characterized in that: The membrane electrode is formed by stacking a cathode electrode, a sealing frame, an anion membrane, a sealing frame and an anode electrode in sequence.

8. The anionic membrane water electrolyzer according to claim 7, characterized in that: The cathode electrode includes a first conductive substrate layer of a plain mesh with 100 mesh openings woven from nickel wires, a nickel-molybdenum catalyst is coated on the surface of the first conductive substrate layer, and the porosity of the first conductive substrate layer is 50%.

9. The anionic membrane water electrolyzer according to claim 7, characterized in that: The anode electrode comprises a second conductive substrate layer of a plain mesh with 100 mesh openings woven from nickel wires, Raney nickel particles are sprayed on the surface of the second conductive substrate layer, and the porosity of the second conductive substrate layer is 50%.

Images