Planar electrode for high-temperature molten salt electrochemical system

Abstract

The embodiment of the utility model discloses a planar electrode for a high-temperature molten salt electrochemical system. The planar electrode comprises an alundum tube; a channel penetrating through two ends of the alundum tube is arranged in the alundum tube; the high-temperature-resistant metal wire is arranged in the channel of the alundum tube; the high-temperature-resistant metal wires extend out of two ends of the corundum tube; wherein one end of the high-temperature-resistant metal wire is flush with one end of the alundum tube, and the inner wall of the alundum tube and the high-temperature-resistant metal wire are sealed to serve as an electrode end of the planar electrode; and the other end of the high-temperature-resistant metal wire extends out of the other end part of the alundum tube to serve as an electrode connecting end. When the electrode is used as an electrode of an electrochemical system, the electrode has a constant area in an electrolyte, is not influenced by the insertion depth of the electrode, is not easily influenced by oxidation, corrosion and material migration, and has a good application prospect in the high-temperature molten salt electrochemical system when being used as a planar electrode with a constant area.

Description

Technical Field

[0001] This utility model belongs to the field of electrochemical metallurgy technology, specifically relating to a planar electrode for high-temperature molten salt electrochemical systems. Background Technology

[0002] In high-temperature molten salt environments, the stability, corrosion resistance, and constant effective working area of ​​electrodes are key factors affecting experimental accuracy and industrial application reliability. Traditional high-temperature electrodes are typically bare metal wires or sheet structures. Electrodes with this structure are susceptible to oxidation, corrosion, and material migration in molten salt, leading to shortened electrode life. Furthermore, due to variations in the electrode's insertion depth in the electrolyte, the effective contact area cannot remain constant, affecting the repeatability and accuracy of test results. Utility Model Content

[0003] In view of this, some embodiments disclose planar electrodes for high-temperature molten salt electrochemical systems, including:

[0004] Corundum tube; the corundum tube has a channel running through both ends;

[0005] High-temperature resistant metal wires are installed in the channels of the corundum tube; the high-temperature resistant metal wires extend from both ends of the corundum tube.

[0006] One end of the high-temperature resistant metal wire is flush with one end of the corundum tube, and the inner wall of the corundum tube is sealed with the high-temperature resistant metal wire, serving as the electrode end of the planar electrode; the other end of the high-temperature resistant metal wire extends from the other end of the corundum tube, serving as the electrode connection end.

[0007] Furthermore, in some embodiments, the planar electrode for a high-temperature molten salt electrochemical system is sealed between the inner wall of the corundum tube and the high-temperature resistant metal wire with a high-temperature resistant adhesive layer.

[0008] Some embodiments disclose planar electrodes for high-temperature molten salt electrochemical systems, wherein the high-temperature resistant metal wire is cylindrical with a diameter of 0.1–0.2 cm.

[0009] Some embodiments disclose planar electrodes for high-temperature molten salt electrochemical systems, wherein the high-temperature resistant metal wire is a polygonal prism with a side length of 0.1 to 0.2 cm.

[0010] Some embodiments disclose planar electrodes for high-temperature molten salt electrochemical systems, wherein the high-temperature resistant adhesive layer is formed by curing a high-temperature resistant adhesive.

[0011] Some embodiments disclose planar electrodes for high-temperature molten salt electrochemical systems, wherein the length of the high-temperature resistant metal wire extending from the other end of the corundum tube is not less than 0.5 cm.

[0012] The planar electrode for high-temperature molten salt electrochemical systems disclosed in this utility model embodiment has a high-temperature resistant metal wire placed inside a corundum tube. The metal wire has a fixed area at the end of the corundum tube. When used as an electrode in an electrochemical system, it can have a constant area in the electrolyte, which is not affected by the electrode insertion depth and is not easily affected by oxidation, corrosion and material migration. As a planar electrode with a constant area, it has good application prospects in high-temperature molten salt electrochemical systems. Attached Figure Description

[0013] Figure 1 Example 1: Schematic diagram of a planar electrode structure for a high-temperature molten salt electrochemical system;

[0014] Figure 2 Example 1: Schematic diagram of the cross-section of a planar electrode used in a high-temperature molten salt electrochemical system.

[0015] Figure Labels

[0016] 1. High-temperature resistant metal wire 2. Corundum tube

[0017] 3. High-temperature resistant adhesive layer Detailed Implementation

[0018] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in these embodiments of the present invention, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used herein is merely for describing particular implementations and is not intended to limit the scope of the disclosure of these embodiments.

[0019] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; other test methods and technical means not specifically noted in this invention refer to test methods and technical means commonly used by one of ordinary skill in the art.

[0020] The terms “basic” and “approximately” used in this document are to describe small fluctuations. For example, they can mean less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Numerical data presented or expressed in range format in this document are used for convenience and brevity only, and should therefore be flexibly interpreted to include not only the explicitly listed values ​​that define the range, but also all independent values ​​or subranges contained within that range. For example, a numerical range of “1–5%” should be interpreted to include not only the explicitly listed values ​​from 1% to 5%, but also the independent values ​​and subranges within the indicated range. Thus, this numerical range includes independent values ​​such as 2%, 3.5%, and 4%, and subranges such as 1%–3%, 2%–4%, and 3%–5%, etc. This principle also applies to ranges that list only one value. Furthermore, this interpretation applies regardless of the width of the range or the characteristics described.

[0021] In this document, including in the claims, conjunctions such as "comprising," "including," "with," "having," "containing," "involving," and "accommodating" are understood to be open-ended, meaning "including but not limited to." Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0022] To better illustrate the content of this utility model, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this utility model can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and equipment well known to those skilled in the art are not described in detail, in order to highlight the main points of this utility model.

[0023] Without conflict, the technical features disclosed in the embodiments of this utility model can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of this utility model.

[0024] In some implementations, such as Figure 1 , Figure 2 As shown, the planar electrode used in the high-temperature molten salt electrochemical system includes:

[0025] The corundum tube 2 is a cylindrical tube with a circular channel running through both ends inside. A high-temperature resistant metal wire 1 is installed inside the circular channel, extending from both ends of the corundum tube. The lower end of the high-temperature resistant metal wire 1 is flush with the lower end face of the corundum tube 2, and a high-temperature resistant layer 3 is used to seal the inner wall of the corundum tube 2 and the high-temperature resistant metal wire, serving as the electrode end of the planar electrode. This end can be placed in the electrolyte melt of the electrolysis system to participate in the electrode reaction. The upper end of the high-temperature resistant metal wire 1 extends from the upper end of the corundum tube 2, serving as the electrode connection end, which can be used to connect to the electrolysis power supply.

[0026] In some embodiments, a high-temperature resistant adhesive layer is used to seal the inner wall of the corundum tube and the high-temperature resistant metal wire. This high-temperature resistant adhesive layer is formed by curing the high-temperature resistant adhesive. For example, the gap between the inner wall of the corundum tube and the high-temperature resistant metal wire can be filled with high-temperature resistant adhesive, and then cured at a set temperature, such as 80–150°C, to form a high-temperature resistant adhesive layer, sealing the gap and enhancing the sealing performance and stability of the electrode. Generally, a high-temperature resistant adhesive layer refers to an adhesive film with stable sealing performance under heat preservation conditions. This film is formed by curing the high-temperature resistant adhesive at a set temperature. For example, the high-temperature resistant inorganic adhesive from Shenzhen Xinwei Electronic Materials Co., Ltd. contains a two-component powder-liquid mixture. After being placed at room temperature for 12–24 hours, it is kept at 80–150°C for 2 hours, then kept at 150°C for 2 hours, and subsequently slowly cooled to form an adhesive layer. This adhesive layer can maintain stable performance within a temperature range of 1000–1730°C and has stable insulation properties, oil resistance, acid and alkali resistance, and water resistance. High-temperature resistant inorganic adhesives with different powder-to-liquid ratios have different insulation properties, oil resistance, acid and alkali resistance, and water resistance properties, and can be selected according to the application environment.

[0027] In some embodiments, the high-temperature resistant metal wire can be tungsten wire or molybdenum wire.

[0028] In some embodiments, the high-temperature resistant metal wire is a cylindrical tungsten wire or molybdenum wire with a diameter of 0.1 to 0.2 cm.

[0029] In some embodiments, the high-temperature resistant metal wire is a polygonal prismatic cylindrical tungsten wire or molybdenum wire, and the side length of the polygonal prismatic shape is 0.1 to 0.2 cm.

[0030] In some embodiments, the method for preparing the planar electrode for a high-temperature molten salt electrochemical system includes:

[0031] (a) Select a corundum tube of appropriate size with a through-hole channel to ensure that it meets the electrode structure requirements;

[0032] (b) Take a molybdenum wire and pass it through the hollow part of the corundum tube so that only the circular cross-section of the molybdenum wire is exposed at the bottom of the corundum tube and flush with the end. The molybdenum wire extends from the top of the corundum tube. The diameter of the molybdenum wire is 0.1 to 0.2 cm. The length of the wire extending from the top is 1 cm.

[0033] (c) Fill the gap between the circular bottom of the molybdenum wire and the inner wall of the corundum tube with high-temperature adhesive, preferably high-temperature resistant inorganic adhesive, to ensure that there is no gap, so as to enhance the sealing and stability of the electrode.

[0034] (d) After filling, the part with high temperature resistant inorganic adhesive at the bottom is cured to cure the high temperature adhesive and improve the overall structural strength; preferably, the high temperature resistant inorganic adhesive has a curing temperature between 100 and 150°C.

[0035] (e) The electrode is allowed to cool naturally to room temperature, thus completing the fabrication of the planar electrode.

[0036] In some embodiments, a molybdenum wire with a diameter of 0.1 cm was selected as the high-temperature resistant metal wire to fabricate the planar electrode. Then, the test was carried out in a NaCl-KCl molten salt system. The bottom end of the molybdenum wire planar electrode was inserted into the NaCl-KCl molten salt at a temperature of 750°C to a depth of 5 cm and the test was carried out continuously for 6 hours. The stability of the molybdenum wire planar electrode was measured by cyclic voltammetry. The results showed that the electrode could still maintain stable electrochemical performance under long-term high-temperature environment, and the test data fluctuated little. The electrode potential change was less than ±5mV, which proved that the molybdenum wire planar electrode had excellent long-term stability in this system.

[0037] In some embodiments, tungsten wire with a diameter of 0.1 cm was selected as the high-temperature resistant metal wire to fabricate the planar electrode. The test was conducted in a NaCl-KCl molten salt system. The bottom end of the tungsten wire planar electrode was inserted into the NaCl-KCl molten salt at a temperature of 750℃ to a depth of 4 cm and the test was conducted continuously for 6 hours. The long-term working performance of the electrode was determined by the constant current method. The results showed that the current response of the electrode remained consistent throughout the entire test cycle, with a variation range of less than ±2%, and there was no obvious corrosion on the electrode surface, indicating that the tungsten wire planar electrode has good corrosion resistance and thermal stability.

[0038] In some embodiments, a molybdenum wire with a diameter of 0.1 cm was selected as the high-temperature resistant metal wire to fabricate the planar electrode. The test was conducted in a NaCl-KCl-KF molten salt system. The bottom end of the molybdenum wire planar electrode was inserted into the NaCl-KCl-KF molten salt at a temperature of 750℃ to a depth of 6 cm and the test was conducted continuously for 6 hours. The conductivity stability of the electrode in the high-temperature molten salt was analyzed by impedance spectroscopy. The results showed that the impedance value of the electrode remained stable at different test time points, with a change of less than ±3%, and there was no obvious degradation of the electrode interface. This indicates that the design can effectively improve the electrode life and stability in the high-temperature molten salt environment.

[0039] The planar electrode for high-temperature molten salt electrochemical systems disclosed in this utility model embodiment has a high-temperature resistant metal wire placed inside a corundum tube. The metal wire has a fixed area at the end of the corundum tube. When used as an electrode in an electrochemical system, it can have a constant area in the electrolyte, which is not affected by the electrode insertion depth and is not easily affected by oxidation, corrosion and material migration. As a planar electrode with a constant area, it has good application prospects in high-temperature molten salt electrochemical systems.

[0040] The technical solutions and technical details disclosed in the embodiments of this utility model are merely illustrative of the inventive concept of this utility model and do not constitute a limitation on the technical solutions of the embodiments of this utility model. Any conventional changes, substitutions or combinations made to the technical details disclosed in the embodiments of this utility model have the same inventive concept as this utility model and are within the protection scope of the claims of this utility model.

Claims

1. A planar electrode for use in high-temperature molten salt electrochemical systems, characterized in that, include: Corundum tube; The corundum tube has a channel running through both ends of it. A high-temperature resistant metal wire is disposed in the channel of the corundum tube; the high-temperature resistant metal wire extends from both ends of the corundum tube; One end of the high-temperature resistant metal wire is flush with one end of the corundum tube, and the inner wall of the corundum tube is sealed with the high-temperature resistant metal wire, serving as the electrode end of the planar electrode; the other end of the high-temperature resistant metal wire extends from the other end of the corundum tube, serving as the electrode connection end.

2. The planar electrode for a high-temperature molten salt electrochemical system according to claim 1, characterized in that, The inner wall of the corundum tube is sealed with a high-temperature resistant adhesive layer between itself and the high-temperature resistant metal wire.

3. The planar electrode for a high-temperature molten salt electrochemical system according to claim 1, characterized in that, The high-temperature resistant metal wire is cylindrical, and the diameter of the cylinder is 0.1 to 0.2 cm.

4. The planar electrode for a high-temperature molten salt electrochemical system according to claim 1, characterized in that, The high-temperature resistant metal wire is a polygonal prism with a side length of 0.1 to 0.2 cm.

5. The planar electrode for a high-temperature molten salt electrochemical system according to claim 2, characterized in that, The high-temperature resistant adhesive layer is formed by curing high-temperature resistant adhesive.

6. The planar electrode for a high-temperature molten salt electrochemical system according to claim 1, characterized in that, The length of the high-temperature resistant metal wire extending from the other end of the corundum tube shall not be less than 0.5 cm.

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