Novel electrolytic bath

Abstract

The invention belongs to the technical field of water electrolysis hydrogen production, and particularly relates to a novel electrolytic bath. Comprising a composite conductive bipolar plate; the composite conductive bipolar plate comprises a pole frame, a bipolar plate and a reinforcing net, the pole frame is arranged on the outer side of the bipolar plate, the surface of the pole frame is made of a non-conductive material, and the bipolar plate is made of a conductive material; the reinforcing net is arranged in the bipolar plate and used for improving the strength of the bipolar plate. According to the invention, the bipolar plate and the electrode frame are combined into a composite piece, and processing means such as injection molding can be adopted, so that the material cost and the processing cost are greatly reduced; no sealing element is used, and the cost of the electrolytic cell is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen production by electrolysis of water, and particularly relates to a novel electrolytic cell. Background Art

[0002] Hydrogen is not only an ideal clean energy carrier, but also an extremely important chemical raw material. The hydrogen obtained by electrolyzing water with renewable energy is called "green hydrogen" and is the future development direction of the energy and chemical industries. The electrolysis technology of hydrogen production is mainly divided into alkaline water electrolysis technology (AWE), proton exchange membrane water electrolysis technology (PEM) and solid oxide water electrolysis technology (SOE). Alkaline water electrolysis has a simple structure, mature technology and low cost. It is the most widely used water electrolysis technology in the field of large-scale hydrogen production.

[0003] like Figure 1-2 As shown, the alkaline water electrolysis hydrogen production device mainly includes an electrolyzer and an auxiliary frame with functions such as gas-liquid separation and purification. The electrolyzer is mainly composed of end pressure plates, bipolar plates 2, electrodes, diaphragms 5, sealing gaskets and bolts, and is the core component of the alkaline water electrolysis hydrogen production device. During operation, the inlet liquid is divided into two and enters the reaction chambers on both sides of the diaphragm 5 respectively. The electrode tank discharges liquid through two channels to the gas-liquid separator I15 and the gas-liquid separator II14, thereby producing oxygen and hydrogen. The electrolyte in the gas-liquid separator I15 and the gas-liquid separator II14 is collected and circulated to the electrolyzer again. On the one hand, it is estimated that in the manufacturing cost of the electrolyzer, bipolar plates account for 44%, sealing materials account for 8%, end pressure plates account for 5%, electrodes account for 28%, and diaphragms account for 8%. The bipolar plate is a key component that affects the manufacturing cost of the electrolyzer. In order to meet the requirements of high-temperature strong alkali corrosion, high-pressure alkaline gas-liquid sealing, porous electrode current collection, electrolyte and gas flow and other functions, the current electrolyzer bipolar plates are generally made of thin carbon steel plates that are precisely stamped into double-sided mastoid plates, and welded to thick carbon steel pole frames, and then nickel-plated as a whole. The thickness of the pole frame and the bipolar plate is different. The reason is that after the bipolar plate is stamped into a double-sided mastoid plate, the mastoid occupies a certain thickness space, which can accommodate the flow of electrolyte, but it leads to a long bipolar plate processing process, and the pole frame and the pole plate need to be processed separately and welded into a whole, which has high material / processing costs, directly leading to an increase in the cost of alkaline water electrolysis hydrogen production equipment, affecting the larger-scale application of alkaline water electrolysis hydrogen production technology. On the other hand, the carbon steel material generally used in bipolar plates is not highly conductive. The electrode and the top of the bipolar plate mastoid are electrically connected by pressing. The contact resistance is large due to pressure, corrosion, etc., which leads to a large voltage drop caused by the resistance of the electrolyzer, which directly leads to an increase in the DC power consumption of the alkaline water electrolysis hydrogen production device. The increase in electrolytic cell resistance also leads to an increase in heat generation power, which further leads to an increase in the heat dissipation demand of the hydrogen production device. The above two important issues have led to an increase in the manufacturing or use costs of alkaline water electrolysis hydrogen production devices, affecting the larger-scale application of alkaline water electrolysis hydrogen production technology. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a new type of electrolyzer to solve the problem of high manufacturing and use costs of traditional alkaline water electrolysis hydrogen production electrolyzers.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a novel electrolytic cell, comprising a composite conductive bipolar plate;

[0007] The composite conductive bipolar plate includes a pole frame, a bipolar plate and a reinforcing mesh, wherein the pole frame is arranged on the outside of the bipolar plate, and the pole frame surface is made of non-conductive material, and the bipolar plate is made of conductive material; the reinforcing mesh is arranged inside the bipolar plate to improve the strength of the bipolar plate.

[0008] The pole frame is provided with a liquid inlet, a liquid outlet and a plurality of flow channels, and the flow channels are used for connecting the liquid inlet, the liquid outlet and the reaction chambers on both sides of the bipolar plate.

[0009] The pole frame is an annular structure, and annular sealing lines are provided on both sides.

[0010] The thickness of the pole frame is 3-20 mm.

[0011] Both sides of the bipolar plate are provided with a plurality of nipples, and the thickness of the bipolar plate is 1-10 mm.

[0012] The bipolar plate is made of a composite material consisting of plastic, conductive powder and reinforced fiber.

[0013] The reinforcing mesh is a stainless steel mesh, an iron mesh, a nickel mesh or a nylon mesh.

[0014] The thickness of the reinforcement mesh is 1-5 mm.

[0015] The two composite conductive bipolar plates are stacked with a diaphragm in between, and an oxygen evolution reaction chamber and a hydrogen evolution reaction chamber are formed on both sides of the diaphragm. An oxygen evolution electrode and a hydrogen evolution electrode are respectively arranged in the oxygen evolution reaction chamber and the hydrogen evolution reaction chamber, and the oxygen evolution electrode and the hydrogen evolution electrode are respectively in contact with the bipolar plates on both sides.

[0016] The multiple electrolytic cells are stacked in sequence, and two adjacent electrolytic cells share one composite conductive bipolar plate; end pressure plates are provided at both ends of the multiple electrolytic cells stacked in sequence, and the multiple electrolytic cells are tightened and fixed by bolts.

[0017] The advantages and beneficial effects of the present invention are as follows: the present invention provides a new type of electrolytic cell, in which the bipolar plate and the pole frame are combined into a composite part, and injection molding and other processing methods can be used to greatly reduce material costs and processing costs; the present invention does not need to use seals, greatly reducing the cost of the electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of a traditional electrolytic cell;

[0019] Figure 2 An exploded view of a conventional electrolyzer;

[0020] Figure 3 This is a schematic diagram of the structure of a novel electrolytic cell of the present invention;

[0021] Figure 4 This is an exploded view of a novel electrolytic cell of the present invention.

[0022] In the figure: 1-polar frame, 2-bipolar plate, 3-seal, 4-oxygen evolution electrode, 5-diaphragm, 6-hydrogen evolution electrode, 7-liquid inlet, 8-papillary, 9-liquid outlet, 10-annular sealing line, 11-traditional bipolar plate welding point, 12-flow channel, 13-diaphragm groove, 14-gas-liquid separator II, 15-gas-liquid separator I, 16-reinforcement mesh, 17-conductive area, 18-non-conductive area. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 3-4 As shown, the present invention provides a new type of electrolytic cell, including a composite conductive bipolar plate; the composite conductive bipolar plate includes a pole frame 1, a bipolar plate 2 and a reinforcing mesh 16, wherein the pole frame 1 is arranged on the outside of the bipolar plate 2, and the surface of the pole frame 1 is made of non-conductive material, thereby forming a non-conductive area 18 at the outer edge of the composite conductive bipolar plate. The bipolar plate 2 is made of conductive material, thereby forming a conductive area 17 in the central part of the composite conductive bipolar plate; the reinforcing mesh 16 is arranged in the bipolar plate 2 to improve the strength of the bipolar plate 2. The present invention combines the bipolar plate and the pole frame into a composite part, and can be processed by injection molding and other processing methods, which greatly reduces material costs and processing costs.

[0025] like Figure 4 As shown, in the embodiment of the present invention, the pole frame 1 is provided with a liquid inlet 7, a liquid outlet 9 and a plurality of flow channels 12, and the flow channels 12 are used to connect the liquid inlet 7, the liquid outlet 9 and the reaction chambers on both sides of the bipolar plate 2.

[0026] Furthermore, the pole frame 1 is an annular structure, and both sides are provided with annular sealing lines 10, so as to seal and connect two adjacent pole frames 1. In this embodiment, the thickness of the pole frame 1 is 3-20 mm, preferably in the range of 5-10 mm.

[0027] like Figure 4As shown, in the embodiment of the present invention, a plurality of nipples 8 are provided on both sides of the bipolar plate 2, and the thickness of the bipolar plate 2 is 1-10 mm, preferably in the range of 2-4 mm.

[0028] In an embodiment of the present invention, the bipolar plate 2 is made of a composite material consisting of plastic, conductive powder and reinforcing fiber, wherein the plastic includes polyethylene, polypropylene, polyvinyl chloride, ABS, PEEK, PTFE, epoxy resin, etc., the conductive powder includes carbon powder, nickel powder, iron powder, etc., the fiber material includes glass fiber, carbon fiber, boron fiber, etc., and the reinforcing mesh 16 is wrapped inside the composite plastic.

[0029] In this embodiment, the reinforcing mesh 16 is a stainless steel mesh, an iron mesh, a nickel mesh or a nylon mesh. The thickness of the reinforcing mesh 16 is 1-5 mm, preferably 1-3 mm. The composite conductive bipolar plate can be processed by integral injection molding, hot pressing molding + plastic welding, etc.

[0030] like Figure 3-4 As shown, in an embodiment of the present invention, two composite conductive bipolar plates are stacked and a diaphragm 5 is arranged in the middle, an oxygen evolution reaction chamber and a hydrogen evolution reaction chamber are formed on both sides of the diaphragm 5, an oxygen evolution electrode 4 and a hydrogen evolution electrode 6 are respectively arranged in the oxygen evolution reaction chamber and the hydrogen evolution reaction chamber, and the oxygen evolution electrode 4 and the hydrogen evolution electrode 6 are respectively in contact with the bipolar plates 2 on both sides.

[0031] like Figure 3 As shown, in an embodiment of the present invention, a plurality of electrolytic cells are stacked in sequence, and a composite conductive bipolar plate is shared between two adjacent electrolytic cells; end pressure plates are provided at both ends of the plurality of electrolytic cells stacked in sequence, and the plurality of electrolytic cells are tightened and fixed by bolts.

[0032] The present invention combines the bipolar plate and the pole frame into a composite part, and can adopt processing methods such as injection molding to greatly reduce material costs and processing costs; the present invention does not need to use sealing parts, greatly reducing the cost of the electrolytic cell.

[0033] Embodiment 1

[0034] A 1mm thick perforated iron mesh, acetylene black carbon powder and PEEK are formed by hot pressing to obtain a conductive area 17, and PEEK is processed by injection molding to obtain a non-conductive area 18. The conductive area 17 and the non-conductive area 18 are ultrasonically welded into a composite conductive bipolar plate integral part with a reaction area of ​​500cm 2, a seal is obtained by CNC processing of a 3mm glass fiber reinforced PTFE plate. The hydrogen evolution electrode 6 uses a nickel mesh sprayed with Raney nickel, the oxygen evolution electrode 4 uses a nickel mesh, the diaphragm 5 uses a PPS cloth, and a 40mm thick end pressure plate is used on both sides of the electrolyzer. The end pressure plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-seal-composite conductive bipolar plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-seal-composite conductive bipolar plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-end pressure plate is stacked in the order of end pressure plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-seal-composite conductive bipolar plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-end pressure plate, and the new electrolyzer is obtained by tightening the screw. The number of electrolyzer chambers is 10. The electrolyzer is installed in the water electrolysis test device. The electrolyte uses a 30% KOH solution, the operating temperature is 90°C, the operating pressure is 0.6MPa, the electrolysis current is 125A, and the electrolyzer processing time and electrolyzer voltage are recorded. In this embodiment, the processing time of the composite conductive bipolar plate is: hot pressing of the conductive area for 5 minutes, hot pressing of the non-conductive area for 5 minutes, plastic welding for 10 minutes, and the total time is 20 minutes. Processing time of the seal: CNC processing for 5 minutes; electrolytic cell voltage: 18.53V; electrolytic cell DC power consumption: 4.43kWh / Nm 3 H 2 .

[0035] Embodiment 2

[0036] A 1mm thick punched iron mesh, nickel powder and soluble polytetrafluoroethylene are used to inject the conductive area 17, and the soluble polytetrafluoroethylene is used to inject the non-conductive area 18, and a composite conductive bipolar plate is obtained by integral injection molding, with a reaction area of ​​500cm 2 . The hydrogen evolution electrode 6 adopts a nickel mesh sprayed with Raney nickel, the oxygen evolution electrode 4 adopts a nickel mesh, the diaphragm 5 adopts PPS cloth, and 40mm thick end pressing plates are used on both sides of the electrolyzer. They are stacked in the order of end pressing plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-composite conductive bipolar plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-composite conductive bipolar plate-hydrogen evolution electrode 6-diaphragm 5-oxygen evolution electrode 4-end pressing plate, and the new electrolyzer is obtained by tightening the screw. The number of electrolyzer chambers is 10. The electrolyzer is installed in the water electrolysis test device. The electrolyte adopts 30% KOH solution, the operating temperature is 90°C, the operating pressure is 0.6MPa, the electrolysis current is 125A, and the electrolyzer processing time and electrolyzer voltage are recorded. In this embodiment, the processing time of the composite conductive bipolar plate integrated part: injection molding 15min. Electrolyzer voltage: 18.56V; DC power consumption of electrolyzer: 4.44kWh / Nm 3 H 2 .

[0037] Comparative Example

[0038] The bipolar plate 2 is obtained by laser cutting and stamping of a 3 mm carbon steel plate, and the pole frame 1 is obtained by laser cutting and CNC processing of a 5 mm carbon steel plate. The bipolar plate 2 and the pole frame 1 are welded and nickel-plated to obtain a bipolar plate and pole frame integrated part, with a reaction area of ​​500 cm2 The seal 3 is made of 3mm glass fiber reinforced PTFE plate by CNC processing, the hydrogen evolution electrode 6 is made of nickel mesh sprayed with Raney nickel, the oxygen evolution electrode 4 is made of nickel mesh, the diaphragm 5 is made of PPS cloth, and the two sides of the electrolytic cell are made of 40mm thick end pressure plates. Figure 1 The electrolytic cell is stacked in the order shown and tightened by the screw to obtain a traditional electrolytic cell with 10 chambers. The electrolytic cell is installed in the water electrolysis test device. The electrolyte is 30% KOH solution, the operating temperature is 90°C, the operating pressure is 0.6MPa, the electrolysis current is 125A, and the electrolytic cell processing time and the electrolytic cell voltage are recorded. In this embodiment, the processing time of the bipolar plate and pole frame integrated parts: bipolar plate laser cutting 1min, bipolar plate stamping 0.5min, pole frame laser cutting 2min, pole frame CNC processing 2h, welding 30min, electroplating 30min, total time 183.5min. Seal processing time: CNC processing 3min; electrolytic cell voltage: 18.18V; electrolytic cell DC power consumption: 4.35kWh / Nm 3 H 2 .

[0039] It can be seen that the processing time of the bipolar plate frame of the traditional electrolytic cell is long and the processing cost is high. The processing time of the new electrolytic cell provided by the present invention is greatly reduced, which can greatly reduce the processing cost of the electrolytic cell.

[0040] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A novel electrolytic cell, characterized in that: including a composite conductive bipolar plate; The composite conductive bipolar plate comprises a pole frame (1), a bipolar plate (2) and a reinforcing mesh (16), wherein the pole frame (1) is arranged on the outside of the bipolar plate (2), and the surface of the pole frame (1) is made of a non-conductive material, while the bipolar plate (2) is made of a conductive material; the reinforcing mesh (16) is arranged inside the bipolar plate (2) to improve the strength of the bipolar plate (2).

2. The novel electrolytic cell according to claim 1, characterized in that: The pole frame (1) is provided with a liquid inlet (7), a liquid outlet (9) and a plurality of flow channels (12), and the flow channels (12) are used to connect the liquid inlet (7), the liquid outlet (9) and the reaction chambers on both sides of the bipolar plate (2).

3. The novel electrolytic cell according to claim 2, characterized in that: The pole frame (1) is an annular structure, and both side surfaces are provided with annular sealing lines (10).

4. The novel electrolytic cell according to claim 3 is characterized in that: The thickness of the pole frame (1) is 3-20 mm.

5. The novel electrolytic cell according to claim 1, characterized in that: Both side surfaces of the bipolar plate (2) are provided with a plurality of nipples (8), and the thickness of the bipolar plate (2) is 1-10 mm.

6. The novel electrolytic cell according to claim 5, characterized in that: The bipolar plate (2) is made of a composite material consisting of plastic, conductive powder and reinforced fibers.

7. The novel electrolytic cell according to claim 1, characterized in that: The reinforcing mesh (16) is a stainless steel mesh, an iron mesh, a nickel mesh or a nylon mesh.

8. The novel electrolytic cell according to claim 7, characterized in that: The thickness of the reinforcing mesh (16) is 1-5 mm.

9. The novel electrolytic cell according to any one of claims 1 to 8, characterized in that: The two composite conductive bipolar plates are stacked with a diaphragm (5) disposed therebetween, an oxygen evolution reaction chamber and a hydrogen evolution reaction chamber are formed on both sides of the diaphragm (5), an oxygen evolution electrode (4) and a hydrogen evolution electrode (6) are disposed in the oxygen evolution reaction chamber and the hydrogen evolution reaction chamber, respectively, and the oxygen evolution electrode (4) and the hydrogen evolution electrode (6) are in contact with the bipolar plates (2) on both sides, respectively.

10. The novel electrolytic cell according to claim 9, characterized in that: The multiple electrolytic cells are stacked in sequence, and two adjacent electrolytic cells share one composite conductive bipolar plate; end pressure plates are provided at both ends of the multiple electrolytic cells stacked in sequence, and the multiple electrolytic cells are tightened and fixed by bolts.

Images