Electrolysis device with air electrode as cathode

Abstract

The utility model relates to the technical field of electrolyzers, and discloses an electrolyzer taking an air electrode as a cathode, which comprises an electrolytic bath body, an electrolytic tin ingot block is arranged in the electrolytic bath body, the electrolytic tin ingot block is electrically connected with a positive electrode of a direct current power supply through a first copper wire, and a group of vertical through holes are arranged on the electrolytic tin ingot block. The air electrode is rolled into a cylinder shape and placed in the through hole, the top of the air electrode is exposed above the electrolytic tin ingot and electrically connected with the negative electrode of the direct-current power source through a second copper wire, and the bottom of the air electrode is flush with the bottom of the electrolytic tin ingot. The air electrode is used as the cathode, the cathode does not generate hydrogen, so that the device is more energy-saving, environment-friendly and safe, the oxygen reaction priority of the cathode is higher than the side reaction generated by sponge tin, and the generation of the sponge tin is greatly reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of electrolysis devices, specifically relating to an electrolysis device with an air electrode as the cathode. Background Technology

[0002] Currently, the electrolysis method used in the workshop involves using pure tin ingots as anode and cathode, placed horizontally with the anode below and the cathode above, separated by a PVC support. Electrolysis is performed under acidic electrolyte conditions with direct current applied. When producing stannous sulfate using direct electrolysis, the tin ingot is directly electrolyzed in the acidic electrolyte. Other impurities and tin in the ingot form anolyte deposits that adhere to the tin block, creating an anode sludge layer that significantly reduces current efficiency. Patent No. 202022609023.6, "Electrolysis Device for Tin Ingots with Through-holes," improves and solves this defect by using a "two-cathode-one-anode" method. The anode sludge produced during electrolysis can precipitate from the through-holes in the tin ingot and the gaps in the support frame to the bottom of the electrolytic cell. However, during electrolysis, metallic tin oxidizes to divalent tin ions at the anode, while metallic tin at the cathode undergoes a hydrogen evolution reaction. This results in a large amount of fluffy sponge tin and hydrogen gas being generated at the cathode while the tin ingot is dissolved at the anode. Excessive formation of sponge tin can cause it to come into contact with the anode plate, leading to a short circuit. This not only wastes current but also significantly reduces electrolysis efficiency. The generation of hydrogen also poses safety risks and increases energy consumption. The presence of sponge tin increases energy consumption and makes cleaning inconvenient. Existing applications all incorporate supports for placing tin blocks in the electrolytic cell, but these supports themselves become sites for sponge tin deposition, requiring frequent cleaning or replacement, increasing costs and operational steps. Furthermore, air electrodes are commonly used in energy storage devices such as metal-air batteries, and are rarely seen in the electrolytic production of stannous sulfate. Therefore, we need to further modify existing electrolysis equipment to address the issues of sponge tin and hydrogen generation during electrolysis. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide an electrolysis device with a simple structure and convenient use, using an air electrode as the cathode.

[0004] To address the aforementioned technical problems, this utility model provides an electrolysis device with an air electrode as the cathode, comprising an electrolysis tank body, an electrolytic tin ingot block disposed within the electrolysis tank body, and the electrolytic tin ingot block being electrically connected to the positive terminal of a DC power supply via a first copper wire.

[0005] The electrolytic tin ingot has a set of vertical through holes. An air electrode is rolled into a cylinder and placed in the through holes. Its top protrudes above the electrolytic tin ingot and is electrically connected to the negative terminal of the DC power supply through a second copper wire. The bottom of the air electrode is flush with the bottom of the electrolytic tin ingot.

[0006] As an improvement to the electrolysis device with an air electrode as the cathode according to this utility model:

[0007] The electrolytic tin ingot is rectangular in shape, with each of the four sides of the top surface extending outward to form four pairs of anode support ears.

[0008] As a further improvement to the electrolysis device with an air electrode as the cathode according to this utility model:

[0009] Four pairs of anode support ears are placed on the top of the electrolytic cell, and one of the anode support ears is electrically connected to the positive terminal of the DC power supply through a first copper wire.

[0010] As a further improvement to the electrolysis device with an air electrode as the cathode according to this utility model:

[0011] The air electrode includes a catalyst layer, a metal conductive substrate, and an air diffusion layer. After the electrolyte is added to the electrolytic cell, the catalyst layer is in close contact with the inner wall of the through hole of the electrolytic tin ingot.

[0012] As a further improvement to the electrolysis device with an air electrode as the cathode according to this utility model:

[0013] The bottom and four sides of the electrolytic tin ingot are separated from the electrolytic cell and do not come into contact with it.

[0014] As a further improvement to the electrolysis device with an air electrode as the cathode according to this utility model:

[0015] The second copper wire is a hard copper core PVC insulated wire, which is electrically connected to the metal conductive substrate.

[0016] The beneficial effects of this utility model are mainly reflected in:

[0017] 1. This utility model can avoid the formation of sponge tin during continuous electrolysis, stabilize electrolysis, reduce manual operation, and save labor costs.

[0018] 2. This utility model uses an air electrode as the cathode, which does not produce hydrogen gas, making it more energy-efficient and environmentally friendly, and eliminating the safety concerns of hydrogen evolution and accumulation; in addition, the oxygen reaction at the cathode has a higher priority than the side reaction of sponge tin formation, greatly reducing the formation of sponge tin.

[0019] 3. The components in the electrolytic cell of this utility model are minimized. Apart from the tin block participating in electrolysis, there are no other redundant components, which reduces costs and simplifies the cleaning process, and has good practical value. Attached Figure Description

[0020] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0021] Figure 1This is a schematic diagram of an air electrode as a cathode electrolysis device according to this utility model;

[0022] Figure 2 This is a top view schematic diagram of an air electrode as a cathode electrolysis device according to this utility model;

[0023] Figure 3 yes Figure 1 A schematic diagram of the cross-section of the air electrode in the diagram. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0025] Example 1: An electrolysis device with an air electrode as the cathode, such as... Figure 1-3 As shown, it includes an electrolytic cell body 1, an air electrode 4, and an electrolytic tin ingot 6.

[0026] The electrolytic cell body 1 is a top-opening tank-shaped container made of acid-resistant and high-strength PVC sheet. An electrolyte drain port 2 with a switch valve is located on the left side of the electrolytic cell body 1 near the bottom, used to drain the electrolyte after electrolysis.

[0027] The electrolytic tin ingot 6 is a rectangular block, integrally cast. Multiple evenly spaced through holes are formed on the ingot 6 to house the air electrode 4. In this embodiment, there are four through holes. At the four corners of the top of the ingot 6, four pairs of anode support ears 61 (also made of tin) extend outwards from the four sides of the top surface. The ingot 6 is placed inside the electrolytic cell 1, with the four pairs of anode support ears 61 resting precisely on top of the cell 1, thus separating the bottom and four sides of the ingot 6 from the cell 1 and preventing contact. The anode support ears 61 are electrically connected to the positive terminal of the DC power supply via a first copper wire 51.

[0028] The air electrode 4 is an existing product and can be the MAFC-GDE-001 electrode from MetAir. The MAFC-GDE-001 electrode is a rectangular flexible film consisting of a three-layer structure: a catalyst layer 41, a metal conductive substrate 42, and an air diffusion layer 43. In use, the air electrode 4 is rolled into a cylindrical shape and placed in the four through holes of the electrolytic tin ingot 6, with its bottom flush with the bottom of the ingot. The catalyst layer 41 adheres to the inner wall of the through holes in the ingot. After adding sulfuric acid solution, the liquid pressure forces the air electrode 4 to adhere tightly to the inner wall of the through holes. The top of the air electrode 4 protrudes above the ingot 6 to connect to the second copper wire 31. Specifically, a hole is made at the top of the air electrode 4, a bolt is inserted into the hole, the second copper wire 31 is wound around the bolt, and the bolt is tightened in the hole with a nut, thus electrically connecting the second copper wire 31 to the metal conductive substrate 42. The other end of the second copper wire 31 is electrically connected to the negative terminal of the DC power supply.

[0029] The second copper wire 31 must be a hard wire, such as BV wire (hard copper core PVC insulated wire). In use, the air electrode 4 is in close contact with the inner wall of the through hole of the electrolytic tin ingot 6, and the top of the air electrode 4 is located above the electrolytic cell body 1. The second copper wire 31 is also pushed up above the electrolytic cell body 1, and can maintain its height by its own hardness, without contacting the electrolyte.

[0030] Electrolytic tin ingot 6 serves as the anode and is the oxidation electrode, oxidizing metallic tin to produce divalent tin ions that combine with sulfate ions to form stannous sulfate. Air electrode 4 serves as the cathode and is the reduction electrode, combining hydrogen ions from sulfuric acid with oxygen to produce water. This causes the oxygen reaction at the cathode to have a higher priority than the side reaction that produces sponge tin, thus greatly reducing the formation of sponge tin.

[0031] The usage process of this utility model is as follows:

[0032] 1. Check if the electrolyte outlet 2 is closed. If it is closed, add dilute sulfuric acid solution with a concentration of 12%-20% from the top of the electrolytic cell 1. Pour the dilute sulfuric acid solution into the inner cavity of the electrolytic cell 1 from top to bottom until the liquid level of the dilute sulfuric acid solution is level with the electrolytic tin ingot 6. Stop adding dilute sulfuric acid. The preparation is complete.

[0033] Sulfuric acid solution is used as electrolyte. The electrolyte fills the space between the electrolytic tin ingot 6 and the electrolytic tank 1, and inside the through hole of the electrolytic tin ingot 6. This makes the air electrode 4 closely attached to the inner wall of the through hole of the electrolytic tin ingot 6. At the same time, the top of the air electrode 4 is higher than the electrolytic tin ingot 6, so that the second copper wire 31 is above the liquid surface and does not come into contact with the dilute sulfuric acid solution.

[0034] 2. Electrolysis

[0035] Turn on the power and start electrolysis. Set the electrolysis current density to 10 A / dm³. 2-14A / dm 2 Start steady-current electrolysis, observe the electrolysis process, and sample the electrolyte at the bottom of the electrolysis tank to detect the electrolyte concentration. Stop electrolysis when the electrolyte concentration at the bottom of the electrolysis tank reaches 180-200 g / L.

[0036] During electrolysis, the electrolytic tin ingot 6 is electrolyzed to generate stannous ions; the air electrode 4 acts as the cathode, combining hydrogen ions in sulfuric acid with oxygen to form water, thereby reducing the concentration of stannous ions in the upper electrolyte and decreasing the formation of sponge tin.

[0037] 3. Electrolyte post-treatment:

[0038] Electrolyte that has been electrolyzed is discharged from electrolyte outlet 2. Electrolyte concentration is sampled and tested simultaneously. When the electrolyte concentration is lower than 130-150 g / L, electrolyte discharge is stopped and electrolyte outlet 2 is closed. Electrolyte in electrolytic cell 1 is replenished with 12%-14% dilute sulfuric acid. After replenishing to the original liquid level, the next round of electrolysis operation continues.

[0039] Finally, it should be noted that the above examples are merely a few specific embodiments of this utility model. Obviously, this utility model is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this utility model should be considered within the protection scope of this utility model.

Claims

1. An electrolysis apparatus using an air electrode as the cathode, characterized in that: It includes an electrolytic cell body (1), and an electrolytic tin ingot (6) is provided inside the electrolytic cell body (1). The electrolytic tin ingot (6) is electrically connected to the positive terminal of a DC power supply through a first copper wire (51). An electrolytic tin ingot (6) is provided with a set of vertical through holes. An air electrode (4) is rolled into a cylinder and placed in the through holes. Its top is exposed above the electrolytic tin ingot (6) and is electrically connected to the negative terminal of the DC power supply through the second copper wire (31). The bottom of the air electrode (4) is flush with the bottom of the electrolytic tin ingot (6).

2. The electrolysis apparatus with an air electrode as the cathode according to claim 1, characterized in that: The electrolytic tin ingot (6) is rectangular in shape, with each of the four sides of the top surface extending outward to form four pairs of anode support ears (61).

3. The electrolysis apparatus with an air electrode as the cathode according to claim 2, characterized in that: Four pairs of anode support ears (61) are placed on the top of the electrolytic cell body (1), and one of the anode support ears (61) is electrically connected to the positive terminal of the DC power supply through the first copper wire (51).

4. An electrolysis apparatus with an air electrode as the cathode according to claim 3, characterized in that: The air electrode (4) includes a catalyst layer (41), a metal conductive substrate (42), and an air diffusion layer (43). After the electrolyte is added to the electrolytic cell (1), the catalyst layer (41) is in close contact with the inner wall of the through hole of the electrolytic tin ingot (6).

5. An electrolysis apparatus with an air electrode as the cathode according to claim 4, characterized in that: The bottom and four sides of the electrolytic tin ingot (6) are separated from the electrolytic cell body (1) and do not come into contact.

6. An electrolysis apparatus using an air electrode as the cathode according to claim 5, characterized in that: The second copper wire (31) is a hard copper core polyvinyl chloride insulated wire, which is electrically connected to the metal conductive substrate (42).

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