Pole frame polar plate and electrolytic bath applying same

Abstract

The pole frame polar plate comprises the pole frame polar plate, the pole frame polar plate is a plastic pole frame polar plate, a plurality of alkali liquor inlets are formed in the bottom of the pole frame polar plate, a hydrogen outlet and an oxygen outlet are formed in the top of the pole frame polar plate, and an inner sealing face and an outer sealing face are arranged on the pole frame polar plate in the circumferential direction of the pole frame polar plate. A plurality of metal pins are arranged in the region, positioned inside the inner sealing surface, of the pole frame pole plate and are embedded into the plastic pole frame pole plate. The plastic electrode frame and the electrode plate are formed through one-time injection molding, subsequent machining and the fixing procedure of the electrode plate and the electrode frame are avoided, the leakage risk is fundamentally eliminated, the electrode frame and the electrode plate are all made of alkali-resisting materials, high in chemical corrosion resistance and free of metal impurities, the risk of electrochemical corrosion is fundamentally eradicated, and the service life of the battery is prolonged. The integrated plastic pole plate and the pole frame greatly reduce the equipment weight and size, simplify the installation, transportation and maintenance, and have obvious cost advantages; and meanwhile, metal pins are embedded in the middle of the polar plate to ensure electron transfer.

Description

Technical Field

[0001] The invention relates to an electrolytic cell, in particular to a pole frame and a pole plate and an electrolytic cell using the pole frame and the pole plate. Background Art

[0002] The development of hydrogen energy will play an important role. As the front end of the hydrogen energy industry chain, water electrolysis for hydrogen production has also attracted much attention. At present, water electrolysis technology is mainly divided into ALK (alkaline electrolysis), PEM, AEM and SOEC (solid oxidation electrolyzer). Among them, PEM has good compatibility with green electricity and high electric density, which is a promising technology. However, PEM currently relies on precious metal electrodes and requires the use of strong acid-resistant materials, so it is expensive. The later research and development direction is low-cost and stable electrodes; and the AEM hydrogen production technology between PEM and ALK integrates two technical advantages, that is, it does not use precious metals while achieving high electric density, and has good compatibility with green electricity fluctuations, but it is currently limited by the stability of the anion diaphragm and the stability of the electrode, and the road to commercialization is still relatively long. SOEC (solid oxidation electrolyzer) relies on high-temperature cracking technology, the reaction temperature is between 600-800, and the requirements for materials are high. It is still in the laboratory research and development stage. ALK has been widely used because of its mature technology and low price. More than 95% of the electrolyzers on the market are alkaline electrolyzers.

[0003] The pole frame and pole plate of the traditional alkaline electrolytic cell chamber are both made of metal. The pole frame requires multiple machining processes to complete. The structure of the pole plate is divided into a nipple structure or a flat plate structure, but both require machining before the following welding and fixation. Nickel plating is still required after welding. The electrolytic cell manufactured with this solution is complex, heavy, and expensive, which poses great challenges to installation, transportation, and maintenance. In addition, the welding of the pole plate and the pole frame will cause electrochemical corrosion, affecting the life of the electrolytic cell. Since the pole frame and the pole plate are both metal parts, they are highly dependent on hoisting. The installation of the electrolytic cell relies on positioning pins for positioning. It is often difficult to assemble due to the size and position deviation of the hole. Frequent plugging and unplugging / shaking causes positioning deviation, which places high demands on the installation worker's skills. In addition, the traditional electrolytic cell design does not support online maintenance and needs to be pulled back to the original factory for replacement, and all gaskets need to be replaced, which is costly.

[0004] At present, there is also a structure of plastic pole frame + metal pole plate, which has the effect of reducing cost and weight to a certain extent. However, the problem of electrochemical corrosion still exists. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a pole frame and a pole plate and an electrolytic cell using the pole frame and the pole plate, which adopts an integrated molding injection molding process to inject the plastic pole frame and the plastic pole plate at one time, thereby simplifying the process and eliminating the risk of electrochemical corrosion.

[0006] Technical solution: The present invention includes a pole frame plate, which is a plastic pole frame plate. A plurality of alkali solution inlets are provided at the bottom of the pole frame plate, a hydrogen outlet and an oxygen outlet are provided at the top of the pole frame plate, and an inner sealing surface and an outer sealing surface are provided along the circumference of the pole frame plate. A plurality of metal pins are arranged in the area of ​​the pole frame plate located inside the inner sealing surface, and the metal pins are embedded in the plastic pole frame plate.

[0007] The metal pins are arranged uniformly or non-uniformly, and the non-uniform arrangement includes non-uniform arrangement in the horizontal direction and non-uniform arrangement in the vertical direction.

[0008] When the metal pins are arranged non-uniformly in the horizontal direction, the distribution of the metal pins shows an alternating pattern of dense / sparse areas in the horizontal direction. The distribution is dense in the area directly opposite the alkali solution inlet and the hydrogen outlet or the oxygen outlet. The spacing of the metal pins in this area is A. The remaining areas are sparsely distributed, and the spacing is controlled between 1.2A-2.0A.

[0009] When the metal pins are arranged non-uniformly in the vertical direction, the metal pins present a distribution pattern of dense bottom inlet-normal middle-sparse top outlet in the vertical direction. The metal pins are densely arranged at the alkali solution inlet, sparsely distributed at the hydrogen outlet or the oxygen outlet, and the distribution density of the metal pins in the area between the alkali solution inlet and the hydrogen outlet or the oxygen outlet is between the two.

[0010] The metal pins and the plastic pole frame and pole plate are integrally injection molded to ensure electron transfer.

[0011] The area between the inner sealing surface and the outer sealing surface is used for mounting a gasket.

[0012] The hydrogen outlet and the oxygen outlet are both provided with outlet water lines to reduce the probability of hydrogen and oxygen mixing.

[0013] When there are multiple hydrogen outlets and oxygen outlets, the hydrogen outlets and the oxygen outlets are cross-distributed, or are respectively distributed on both sides of the pole frame and the pole plate.

[0014] The corners of the pole frame and the pole plate are also provided with a plurality of positioning structures, and the positioning structures adopt a concave-convex matching structure to realize the positioning and installation between the plurality of electrolytic chambers.

[0015] An electrolytic cell using the above-mentioned pole frame and pole plate, one end of the electrolytic cell is an anode plate, the other end is a cathode plate, and a plurality of pole frame and pole plates are arranged in the middle to divide the electrolytic cell into a plurality of small chambers; electrodes are arranged on opposite sides of adjacent pole frame and pole plates, and the polarities of the electrodes are opposite, and a diaphragm and a gasket are arranged between every two pole frame and pole plates, and the gasket ensures the internal and external sealing of the electrolytic chamber.

[0016] Beneficial effects: The present invention has the following advantages:

[0017] (1) The plastic pole frame and plastic pole plate are molded by injection molding in one step, which avoids the subsequent machining and the fixing process of the pole plate and pole frame, and the leakage risk is fundamentally eliminated. In addition, the weight of the one-piece plastic pole frame and pole plate is reduced by more than 80% compared with the traditional metal pole frame and pole plate. The pole frame and pole plate are all made of alkali-resistant materials, have strong chemical corrosion resistance, and are free of metal impurities, which fundamentally eliminates the risk of electrochemical corrosion. In addition, the one-piece plastic pole plate and pole frame greatly reduces the weight and size of the equipment, simplifies installation, transportation and maintenance, and has obvious cost advantages.

[0018] (2) A metal pin is embedded in the middle of the electrode plate to ensure electron transfer. The seal between the metal pin and the electrode plate is formed during injection molding. The metal pin can be distributed in a non-uniform manner to improve the electrolysis efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a side view of the pole frame and pole plate of the present invention;

[0020] Figure 2 It is a three-dimensional diagram of the pole frame and pole plate of the present invention;

[0021] Figure 3 is a cross-sectional view of the pole frame and pole plate of the present invention at the middle pole plate;

[0022] Figure 4 It is a schematic diagram of the distribution of metal pins on the pole frame and pole plate of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings.

[0024] The pole frame and pole plate of the present invention are one-piece plastic pole frame and pole plate, which are made by one-piece injection molding process. The material is alkali-resistant plastic material, such as PSU or PPSU, etc., which has strong chemical corrosion resistance and no metal impurities, which fundamentally eliminates the risk of electrochemical corrosion. In addition, the one-piece plastic pole plate and pole frame greatly reduce the weight of the equipment, simplify installation, transportation and maintenance, and reduce costs. The shape can be round, square or other shapes. This embodiment takes a square-structured pole frame and pole plate as an example.

[0025] like Figures 1 to 3 As shown, the pole frame plate of this embodiment includes an alkali liquid inlet 1, a hydrogen outlet 2 and an oxygen outlet 3. A plurality of alkali liquid inlets 1 are provided at the bottom of the pole frame plate, and a hydrogen outlet 2 and an oxygen outlet 3 are provided at the top of the pole frame plate. An outlet water line 4 is provided at both the hydrogen outlet 2 and the oxygen outlet 3 to reduce the probability of hydrogen and oxygen being mixed. The number of hydrogen outlets 2 and oxygen outlets 3 can be determined according to actual conditions. When there are multiple outlets, the hydrogen outlet 2 and the oxygen outlet 3 can be cross-distributed, or they can be distributed on both sides of the pole frame plate.

[0026] In order to ensure sealing, the pole frame and the pole plate are provided with an inner sealing surface 6 and an outer sealing surface 5 along their circumference. The sealing surface can add sealing waterline features as needed. The area between the inner sealing surface 6 and the outer sealing surface 5 is used to install the gasket. At the same time, a plurality of positioning structures 8 are also provided at the corners of the pole frame and the pole plate. The positioning structure 8 is arranged in the area between the inner sealing surface 6 and the outer sealing surface 5. The positioning structure 8 adopts a concave-convex matching structure to realize the positioning installation between multiple electrolysis chambers.

[0027] A plurality of metal pins 7 are arranged in the area inside the inner sealing surface 6 of the pole frame and the pole plate. The metal pins 7 are embedded in the plastic pole frame and the pole plate and are integrally injection molded with the plastic pole frame and the pole plate. The function of the metal pins 7 is to transfer electrons while providing physical space for the flow of alkali solution and gas. The metal pins 7 are in contact with the electrodes, so the hydrogen evolution and oxygen evolution reactions are more intense in the electrode parts in contact with the metal pins 7.

[0028] The arrangement of the metal pins 7 can be uniform, such as Figure 1 As shown, it is also possible to use Figure 4 The non-uniform arrangement shown includes non-uniform arrangement in the horizontal direction and non-uniform arrangement in the vertical direction.

[0029] like Figure 4 As shown, when the metal pins 7 are arranged in a non-uniform manner in the horizontal direction, the metal pins 7 are densely distributed in the area directly opposite to the alkali liquid inlet 1 and the hydrogen outlet 2 or the oxygen outlet 3, and the spacing of the metal pins 7 in this area is A. The remaining areas are sparsely distributed, and the spacing is controlled between 1.2A-2.0A. The distribution of the entire metal pins 7 shows a change pattern of alternating dense / sparse areas in the horizontal direction. According to the law of fluid movement, the alkali liquid flow rate is faster in the area directly opposite to the alkali liquid inlet 1 and the hydrogen outlet 2 or the oxygen outlet 3. Under the action of fluid flushing, the hydrogen and oxygen bubbles in this area are easy to fall off and the electrolysis efficiency is high. Therefore, the metal pins 7 should be densely arranged; in other areas, the alkali liquid flow rate is slower, the bubbles fall off slowly, and the performance of the electrode in this area is not fully utilized, so the arrangement of the metal pins 7 should be sparse.

[0030] When the metal pins 7 are arranged non-uniformly in the vertical direction, the metal pins follow the distribution rule of "dense bottom inlet - normal middle - sparse top outlet" in the vertical direction, that is, the metal pins 7 are densely arranged at the alkali solution inlet 1, and the metal pins 7 are sparsely distributed at the hydrogen outlet 2 or the oxygen outlet 3, and the distribution density of the metal pins 7 in the area between the alkali solution inlet 1 and the hydrogen outlet 2 or the oxygen outlet 3 is between the two. At a cell voltage of about 2.0V, the electrode continuously releases heat, but considering the life and stability of the diaphragm, the cell temperature does not exceed 90 degrees, and there is a temperature difference in the height direction of the cell, that is, the alkali solution inlet temperature is about 75 degrees, and the temperature rises with the increase of height, and the outlet temperature is about 90 degrees. The higher the temperature, the better the electrolysis effect, so the dense arrangement at the bottom can quickly increase the temperature of the alkali solution, thereby improving the electrolysis efficiency of the entire cell.

[0031] The present invention also includes an electrolytic cell using the above-mentioned pole frame plates, one end of the electrolytic cell is an anode plate, the other end is a cathode plate, and a plurality of pole frame plates are arranged in the middle to divide the electrolytic cell into a plurality of small chambers. Electrodes are arranged on opposite sides of adjacent pole frame plates, and the polarities of the electrodes are opposite. A diaphragm and a gasket are arranged between every two pole frame plates, and the gasket is used to ensure the inner and outer sealing of the electrolytic chamber. Under the total potential of the anode plate and the cathode plate, the potential is evenly distributed among the pole frame plates in the middle, so that each small chamber constitutes an electrolytic cell with an anode plate and a cathode plate.

[0032] Working principle: lye flows in from the bottom and is distributed to the small chambers between the pole frames and pole plates through the lye inlet. As the lye rises, the cathode and anode continuously produce hydrogen and oxygen, and the temperature continues to rise. The mixture of hydrogen, oxygen and lye reaches their respective outlets and flows out of the electrolyzer. During the working process, the plastic pole plate isolates the gas mixture on both sides to prevent cross-gas. The metal pin is responsible for electronic transmission and provides space for the flow of lye and gas. The overall injection molding process is adopted, which eliminates the processes of processing, testing, welding, electroplating, etc., greatly simplifies the process and reduces the cost.

Claims

1. A pole frame and pole plate, characterized in that: It includes a pole frame and a pole plate, wherein the pole frame and the pole plate adopt a plastic pole frame, and a plurality of metal pins are arranged inside the pole plate of the pole frame, and the metal pins are embedded in the plastic pole frame. When the metal pins are arranged in a non-uniform manner, the distribution of the metal pins presents a pattern of alternating dense / sparse areas in the horizontal direction, and the metal pins present a pattern of dense bottom inlet-normal middle-sparse top outlet in the vertical direction.

2. A pole frame and pole plate according to claim 1, characterized in that: The distribution of the metal pins shows an alternating pattern of dense / sparse areas in the horizontal direction, specifically: the distribution is dense in the area opposite to the alkali solution inlet and the hydrogen outlet or the oxygen outlet, and the spacing of the metal pins in this area is A, and the remaining areas are sparsely distributed, and the spacing is controlled between 1.2A-2.0A.

3. A pole frame and pole plate according to claim 1, characterized in that: The metal pins present a distribution pattern of dense bottom inlet-normal middle-sparse top outlet in the vertical direction, specifically: the metal pins are densely arranged at the alkali solution inlet, sparsely distributed at the hydrogen outlet or the oxygen outlet, and the distribution density of the metal pins in the area between the alkali solution inlet and the hydrogen outlet or the oxygen outlet is between the two.

4. A pole frame and pole plate according to claim 1, characterized in that: The metal pins may also be arranged evenly.

5. The pole frame and pole plate according to claim 1, characterized in that: The pole frame and the pole plate are provided with an inner sealing surface and an outer sealing surface along the circumference thereof, and the metal pin is arranged in the area inside the inner sealing surface.

6. A pole frame and pole plate according to claim 5, characterized in that: The area between the inner sealing surface and the outer sealing surface is used for mounting a gasket.

7. A pole frame and pole plate according to claim 2 or 3, characterized in that: The hydrogen outlet and the oxygen outlet are both provided with outlet water lines.

8. A pole frame and pole plate according to claim 7, characterized in that: When there are multiple hydrogen outlets and oxygen outlets, the hydrogen outlets and the oxygen outlets are cross-distributed, or are respectively distributed on both sides of the pole frame and the pole plate.

9. The pole frame and pole plate according to claim 1, characterized in that: The pole frame and the pole plate are also provided with a plurality of positioning structures.

10. An electrolytic cell using the pole frame and pole plate according to any one of claims 1 to 9, characterized in that: One end of the electrolytic cell is an anode plate, the other end is a cathode plate, and there are several pole frame plates in the middle to divide the electrolytic cell into multiple small chambers; electrodes are provided on opposite sides of adjacent pole frame plates, and the electrode polarities are opposite, and a diaphragm and a gasket are provided between every two pole frame plates.

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