Coated electrode and method for repairing same

Abstract

This invention provides a coated electrode and its repair method. The repair method of this invention uses an electrode repair solution comprising a plating agent, a stabilizer, and an organic solvent. The stabilized, complexed coating active material diffuses to the cracks and gaps on the surface of the electrode to be repaired. Through periodic electrodeposition, a rapid and sequential reaction occurs, involving the dissolution of the original coating and oxide layer, and the deposition of the plating material to form a new coating. The old and new coatings effectively bond together, completing the filling process. In this repair method, for electrodes retaining the original coating, multiple periodic electrodeposition and sintering processes are performed. The new coating fills the cracks and gaps formed after the original coating on the surface of the electrode to be repaired, forming a stable bond with the original coating. The repaired coated electrode has a service life up to 60% of that of a brand-new coated electrode. It features high utilization of precious metal coatings, eliminates the need for complex pretreatment steps such as additional heating and vacuum control, has high repair efficiency, uses simple equipment, and reduces repair costs.

Description

Technical Field

[0001] This invention belongs to the field of electrode repair and regeneration technology, and particularly relates to a coated electrode and its repair method. Background Technology

[0002] Titanium-based metal oxide coated electrodes exhibit excellent electrocatalytic performance in electrode reactions and are widely used as anodes in electrolysis industries such as chlor-alkali electrolysis and metal electrowinning. Their catalytic characteristics for oxidation reactions such as oxygen evolution and chlorine evolution are mainly determined by their surface catalytic coating, which is primarily composed of noble metal oxides such as iridium and ruthenium, and doped with metals such as tin and lead. In actual use in the electrolysis industry, this coating often suffers surface wear or cracking due to physical damage and the influence of impurities in the electrolyte. The coating fails when its loss reaches 20-50%, leading to increased electrolysis energy consumption and economic losses. Coated electrodes originally designed for a service life of 8-10 years typically require replacement after 2-3 years due to insufficient catalytic activity. Because the preparation process of coated electrodes is complex, and the costs of titanium substrates, noble metal coating materials, and reagents are high, it is considered to refurbish failed coated electrodes by repairing them, achieving a lower time, labor, and material cost compared to complete reconstruction, thus extending the electrode's service life.

[0003] Due to the uneven distribution, oxidation, and varying degrees of wear of the original coating on the electrode surface to be repaired, the repair of coated electrodes mainly includes a pretreatment step and a new coating preparation step. The pretreatment step requires that the surface condition of the electrode to be repaired meet the requirements of the new coating preparation method for substrate flatness, adhesion, and reactivity. New coating preparation methods mainly include coating, spraying, and electrodeposition. Among these, coating and spraying methods have high requirements for substrate flatness, and the corresponding pretreatment methods mainly include molten salt method, acid boiling method, and sulfate electrolysis method. Pretreatment causes local structural changes or peeling of the original coating nanostructure of the electrode to be repaired under physical and chemical reactions, restoring substrate flatness. Existing technology discloses an electrode coating repair device that pretreatments the coated electrode to be repaired using high-temperature vacuum, making the original coating evenly distributed on the substrate surface and restoring flatness. This achieves the coating preparation conditions of the coating method, supplementing the coating load, and ultimately retaining the original coating while improving the utilization rate of precious metals. However, when the degree of wear on the electrode surface to be repaired and the distribution of residual coatings are different, the local nanostructure rearrangement is difficult to restore the overall plane to flatness and the coating to uniform distribution. Therefore, it can only be combined with the coating method for overall coverage, which results in a waste of energy and raw materials. In addition, the high temperature vacuum conditions are expensive to implement in actual production and are not easy to achieve.

[0004] Electrodeposition is a relatively ideal method for electrode repair. By controlling operating parameters such as electrolyte concentration, temperature, and charge during electrodeposition, the coating application can be controlled, achieving nanoscale customization of the coating. Furthermore, the repair process and equipment are simple. Existing technology discloses a method for preparing an intermediate layer using a coating method and then electrodepositing an iridium oxide coating under constant current. This method uses an electrolyte solution with a low content of active materials, resulting in good uniformity of the new electrode nano-coating on a smooth substrate surface. However, for electrodes that have failed due to surface cracking, the coating is preferentially consumed on the surface of the residual coating, making it impossible to fill and repair the damaged area. According to existing formulations, when the concentration of active materials in the plating solution rises to 10 mM, precipitation occurs, leading to poor adhesion between the old and new coatings after electrodeposition, making it difficult to achieve a repair effect.

[0005] Currently, there are no publicly available documents describing repair techniques or formulations of high-concentration plating active substances that can fill and repair cracked parts of the electrode to be repaired, effectively extend the service life of the coated electrode. Summary of the Invention

[0006] In view of this, the present invention proposes a coated electrode and a repair method thereof to solve the technical problems existing in the prior art.

[0007] In a first aspect, the present invention provides a method for repairing a coated electrode, comprising the following steps:

[0008] S1. Prepare electrode repair solution;

[0009] S2. Immerse the coated electrode to be repaired in the electrode repair solution and perform periodic electrodeposition to form a repaired coating on the surface of the coated electrode.

[0010] S3. Calcine the repaired coated electrode;

[0011] The electrode repair solution includes a plating agent, a stabilizer, and an organic solvent.

[0012] The coating agent includes a trivalent iridium salt;

[0013] The stabilizer includes an organic acid complexing agent.

[0014] Preferably, the periodic electrodeposition method for repairing the coated electrode is a cyclic voltammetric electrodeposition method. Specifically, the cyclic voltammetric electrodeposition method includes: using the coated electrode to be repaired as the anode, a titanium electrode as the cathode, and a saturated calomel electrode as the reference electrode, performing electrodeposition using a three-electrode system; controlling the voltage range during electrodeposition to -0.2V to 0.7V, the scan rate to 30-50mV / s, with one cycle consisting of the voltage increasing from -0.2V to 0.7V and then returning to -0.2V, and one cycle consisting of 15 to 25 cycles.

[0015] Preferably, in the method for repairing the coated electrode, the temperature of the electrode repair solution is controlled at 35–40°C during the electrodeposition process.

[0016] Preferably, in the method for repairing the coated electrode, the trivalent iridium salt includes iridium salts and / or iridium trichloride;

[0017] The organic acid complexing agent includes citric acid and / or tartaric acid;

[0018] The organic solvent includes at least one of N-methylpyrrolidone, N,N-dimethylformamide, and isopropanol.

[0019] Preferably, in the method for repairing the coated electrode, the iridium ion concentration of the electrode repair solution is 20 mmol / L to 200 mmol / L.

[0020] Preferably, in the method for repairing the coated electrode, the step of calcining the repaired coated electrode involves a calcination temperature of 400–500°C and a time of 10–30 min.

[0021] Preferably, the method for repairing the coated electrode involves immersing the coated electrode to be repaired in an electrode repair solution and performing periodic electrodeposition to form a repaired coating on the surface of the coated electrode to be repaired, wherein the iridium loading of the repaired coating is 1 to 3 μg.

[0022] Repeat steps S2 to S3 5 to 10 times.

[0023] Preferably, in the method for repairing the coated electrode, an alkaline solution is added to the electrode repair solution before electrodeposition to adjust its pH to be greater than 8.

[0024] Alternatively, oxidizing agents may be added to the electrode repair solution before electrodeposition.

[0025] Preferably, in the method for repairing the coated electrode, the alkaline solution includes at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0026] The oxidizing substance is hydrogen peroxide.

[0027] Secondly, the present invention also provides a coated electrode, which is repaired using the aforementioned repair method.

[0028] The repair method for coated electrodes of the present invention has the following advantages over the prior art:

[0029] The present invention relates to a method for repairing coated electrodes. This method utilizes an electrode repair solution as an electrolyte to perform periodic electrodeposition on the coated electrode to be repaired, forming a repaired coating on its surface, followed by calcination. The thickened electrode repair solution of the present invention includes a plating agent, a stabilizer, and an organic solvent. The stabilized complexed coating active material can diffuse to the cracks and gaps on the surface of the electrode to be repaired. Through periodic electrodeposition, a rapid and sequential reaction occurs, involving the dissolution of the original coating and oxide layer, and the deposition of plating material to form a new coating. The old and new coatings effectively bond together to complete the filling. By controlling the coating repair degree and the utilization rate of precious metals through loading, after multiple repeated sintering, the coating is stably bonded to the electrode surface, effectively restoring the electrode's service life. The repair method for coated electrodes of the present invention involves repeatedly performing periodic electrodeposition and sintering treatments on the electrode to be repaired while retaining the original coating. The new coating fills the cracks and gaps formed after the original coating on the surface of the electrode to be repaired cracks and falls off, forming a stable bond with the original coating. The service life of the repaired coated electrode is up to 60% of that of a brand new coated electrode. The utilization rate of the precious metal coating is high, and there is no need for complex pretreatment steps such as additional heat and vacuum control. The repair efficiency is high, and the simple device reduces the repair cost. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a 100x magnified SEM image of the surface of the coated electrode to be repaired used in Example 1.

[0032] Figure 2 This is a 5000x magnified SEM image of the coated electrode surface to be repaired used in Example 1.

[0033] Figure 3 This is a 100x magnified SEM image of the repaired electrode surface in Example 1.

[0034] Figure 4 This is a 5000x magnified SEM image of the repaired electrode surface in Example 1.

[0035] Figure 5 This is a comparison chart of accelerated aging test voltage-time data for the coated electrode to be repaired used in Example 1 and the repaired electrode in Example 1.

[0036] Figure 6A comparison chart of linear sweep voltammetry test data after accelerated aging for 300 hours for the newly prepared coated electrode, the repaired electrode in Example 1, and the repaired electrode in Example 1. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single digits within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0039] This invention provides a method for repairing coated electrodes, comprising the following steps:

[0040] S1. Prepare electrode repair solution;

[0041] S2. Immerse the coated electrode to be repaired in the electrode repair solution and perform periodic electrodeposition to form a repaired coating on the surface of the coated electrode.

[0042] S3. Calcine the repaired coated electrode;

[0043] The electrode repair solution includes plating agent, stabilizer, and organic solvent;

[0044] The coating agent includes trivalent iridium salts;

[0045] Stabilizers include organic acid complexing agents.

[0046] It should be noted that the coating electrode repair method of the present invention utilizes an electrode repair solution as an electrolyte to perform periodic electrodeposition on the coating electrode to be repaired, forming a repaired coating on its surface, followed by calcination. Specifically, the present invention uses a thickened electrode repair solution with a high content of plating active materials and periodic electrodeposition technology. The repair process is simple, energy-efficient, and has a high utilization rate of precious metals, effectively extending the service life of the coating electrode. Furthermore, the electrolyte in the repair device can be reused multiple times. The thickened electrode repair solution of the present invention includes a plating agent, a stabilizer, and an organic solvent. The stable complexed coating active materials can diffuse to the cracks and gaps on the surface of the electrode to be repaired. Through periodic electrodeposition, a rapid and consecutive reaction occurs, involving the dissolution of the original coating and oxide layer and the deposition of plating materials to form a new coating. The old and new coatings effectively combine to complete the filling. By controlling the coating repair degree and the utilization rate of precious metals through the loading, after multiple repeated sintering, the coating is stably bonded to the electrode surface, effectively restoring the electrode's service life. The repair method for coated electrodes of the present invention involves repeatedly performing periodic electrodeposition and sintering treatments on the electrode to be repaired while retaining the original coating. The new coating fills the cracks and gaps formed after the original coating on the surface of the electrode to be repaired cracks and falls off, forming a stable bond with the original coating.

[0047] Specifically, the coating electrode to be repaired mentioned in this application is a titanium-based metal oxide coating electrode, also known as DSA. It uses titanium as a substrate and applies a noble metal coating to the titanium substrate, including titanium-based ruthenium-based coating electrode, titanium-based iridium-based coating electrode, titanium-based manganese dioxide electrode, and titanium-based lead dioxide electrode.

[0048] In some embodiments, the periodic electrodeposition is cyclic voltammetric electrodeposition, which specifically includes: using a three-electrode system with the coating electrode to be repaired as the anode, a titanium electrode as the cathode, and a saturated calomel electrode as the reference electrode; during electrodeposition, the voltage range is controlled to be -0.2V to 0.7V, the scan rate is 30-50mV / s, one cycle is defined as the voltage going from -0.2V to 0.7V and back to -0.2V, and one cycle is defined as 15 to 25 cycles.

[0049] Specifically, in the above embodiments, during the electrodeposition process, a three-electrode system is used for cyclic voltammetry electrodeposition. The electrode to be repaired serves as the working electrode, and the titanium electrode serves as the auxiliary electrode, also known as the counter electrode. The working electrode and the auxiliary electrode form a circuit, and the working electrode and the reference electrode form another circuit. During electrodeposition, the voltage range is controlled, i.e., the potential difference between the working electrode and the reference electrode. During the electrodeposition process, multiple cycles are performed according to the above-controlled process conditions, and the iridium loading of the repaired coating on the surface of the electrode to be repaired reaches a predetermined value.

[0050] In some embodiments, the temperature of the electrode repair solution is controlled at 35–40°C during the electrodeposition process.

[0051] In some embodiments, trivalent iridium salts include iridium salts and / or iridium trichloride;

[0052] In some embodiments, the organic acid complexing agent includes citric acid and / or tartaric acid;

[0053] In some embodiments, the organic solvent includes at least one of N-methylpyrrolidone, N,N-dimethylformamide, and isopropanol.

[0054] In some embodiments, the iridium ion concentration of the electrode repair solution is 20 mmol / L to 200 mmol / L.

[0055] Specifically, in the above embodiments, trivalent iridium salt and organic acid complexing agent are added to an organic solvent and kept at 40-50°C for 5-10 minutes to obtain an electrode repair solution.

[0056] In some embodiments, in the step of calcining the repaired coated electrode, the calcination temperature is 400-500°C and the time is 10-30 min.

[0057] In some embodiments, the coated electrode to be repaired is immersed in an electrode repair solution and periodically electrodeposited to form a repaired coating on the surface of the coated electrode. The iridium loading of the repaired coating is 1–3 μg / cm³. 2 ;

[0058] Repeat steps S2 to S3 5 to 10 times.

[0059] Specifically, in the above embodiments, in step S2, the coated electrode to be repaired is immersed in the electrode repair solution and periodically electrodeposited to form a repaired coating on the surface of the coated electrode, and the iridium loading of the repaired coating is 1-3 μg / cm³. 2 S3. Calcine the repaired coated electrode. In practice, the number of times to repeat steps S2 to S3 is set according to the electrodeposition parameters. That is, the number of times to repeat electrodeposition and calcination is determined according to the actual situation. For example, repeat steps S2 to S3 5 to 10 times, that is, repeat electrodeposition and calcination 5 to 10 times, so that the coating is stably bonded to the surface of the electrode to be repaired, and finally the repair of the coated electrode is completed.

[0060] In some embodiments, an alkaline solution is added to the electrode repair solution before electrodeposition to adjust its pH to be greater than 8; for example, adjusting its pH to 9 to 12.

[0061] Alternatively, in some embodiments, an oxidizing agent is added to the electrode repair solution prior to electrodeposition. Adding an oxidizing agent to the electrode repair solution eliminates the need for pH adjustment.

[0062] In some embodiments, the alkaline solution includes at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0063] In some embodiments, the oxidizing agent is hydrogen peroxide.

[0064] Specifically, in some embodiments, IrCl3, citric acid, and hydrogen peroxide are added to isopropanol and kept at 40–50°C for 5–10 min to obtain the electrode repair solution; wherein the concentration of IrCl3 is 20 mmol / L–200 mmol / L, the concentration of citric acid is 0.05–0.2 mol / L, and the concentration of hydrogen peroxide is 0.2–1 mol / L.

[0065] In some embodiments, IrCl3 and citric acid are added to N-methylpyrrolidone, and then the pH is adjusted to 10-12. The solution is kept at 40-50°C for 5-10 minutes to obtain the electrode repair solution. The concentration of IrCl3 is 20 mmol / L-200 mmol / L and the concentration of citric acid is 0.05-0.2 mol / L.

[0066] In some embodiments, in step S2, the coated electrode to be repaired is immersed in an electrode repair solution and periodically electrodeposited to form a repaired coating on the surface of the coated electrode; then the coated electrode is dried; then the dried coated electrode is calcined; wherein the drying method is air drying or heating to dry the coated electrode.

[0067] In some embodiments, before repairing the coated electrode to be repaired, a pretreatment of the coated electrode to be repaired is further included. The pretreatment specifically includes: immersing the coated electrode to be repaired in water at 40-50°C, while brushing the damaged parts of the coating on the surface of the coated electrode to be repaired, taking care to retain the undamaged parts of the coating; or, the pretreatment includes: immersing the coated electrode to be repaired in a 10-15 wt.% oxalic acid dihydrate aqueous solution for 10-30 minutes, and then washing it with deionized water.

[0068] Based on the same inventive concept, the present invention also provides a coated electrode, which is repaired using the above-described repair method.

[0069] The following specific embodiments further illustrate the repair method for the coated electrode of this application. This section further describes the content of the present invention in conjunction with specific embodiments, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0070] Example 1

[0071] This application provides a method for repairing a coated electrode, comprising the following steps:

[0072] S1. Add IrCl3, citric acid, and hydrogen peroxide to isopropanol and incubate at 45°C for 8 minutes to obtain the electrode repair solution; wherein the concentration of IrCl3 is 160 mmol / L, the concentration of citric acid is 0.1 mol / L, and the concentration of hydrogen peroxide is 0.5 mol / L.

[0073] S2. Immerse the coated electrode to be repaired (specifically, a failed commercial titanium-based iridium coated electrode) in water at 40°C, while simultaneously brushing the damaged parts of the coating on the surface of the coated electrode to be repaired, leaving the undamaged parts of the coating intact.

[0074] S3. Immerse the treated electrode to be repaired from S2 into the electrode repair solution from S1. Using the electrode to be repaired as the anode, a titanium electrode as the cathode, and a saturated calomel electrode as the reference electrode, perform cyclic voltammetry electrodeposition using a three-electrode system. During electrodeposition, control the voltage range to be -0.2V to 0.7V, the scan rate to be 30mV / s, and the temperature of the electrode repair solution to be 38℃. One cycle consists of the voltage increasing from -0.2V to 0.7V and then returning to -0.2V. Perform multiple cycles of electrodeposition to form a repaired coating on the surface of the electrode to be repaired. The iridium loading of the repaired coating is 3μg / cm³. 2 ;

[0075] S4. After the coated electrode repaired in S3 is air-dried, it is sintered at 450℃ for 10 minutes and then cooled to room temperature.

[0076] S5. Repeat steps S3 to S4 6 times to complete the coating repair and obtain the repaired iridium-coated electrode.

[0077] Example 2

[0078] This application provides a method for repairing a coated electrode, comprising the following steps:

[0079] S1. Add IrCl3 and citric acid to N-methylpyrrolidone, then adjust the pH to 10, and keep it at 45℃ for 8 min to obtain the electrode repair solution; wherein, the concentration of IrCl3 is 66 mmol / L and the concentration of citric acid is 0.1 mol / L;

[0080] S2. Immerse the coated electrode to be repaired (specifically, the failed commercial titanium-based iridium coated electrode) in acid etching solution for 30 minutes, and then wash with deionized water.

[0081] S3. Immerse the treated electrode to be repaired from S2 into the electrode repair solution from S1. Using the electrode to be repaired as the anode, a titanium electrode as the cathode, and a saturated calomel electrode as the reference electrode, perform cyclic voltammetry electrodeposition using a three-electrode system. During electrodeposition, control the voltage range to be -0.2V to 0.7V, the scan rate to be 50mV / s, and the temperature of the electrode repair solution to be 38℃. One cycle consists of the voltage increasing from -0.2V to 0.7V and then returning to -0.2V. Perform multiple cycles of electrodeposition to form a repaired coating on the surface of the electrode to be repaired. The iridium loading of the repaired coating is 2μg / cm³. 2 ;

[0082] S4. After the coated electrode repaired in S3 is air-dried, it is sintered at 450℃ for 10 minutes and then cooled to room temperature.

[0083] S5. Repeat steps S3 to S4 8 times to complete the coating repair and obtain the repaired iridium-coated electrode.

[0084] Performance testing

[0085] Figures 1-2 The image shows the morphology of the coated electrode surface to be repaired, magnified 100x to 5000x in Example 1.

[0086] Figures 3-4 The images show the 100x and 5000x magnified morphology of the repaired electrode surface in Example 1. Figures 3-4 It can be seen that IrO2 is deposited on the surface of the electrode to be repaired and at the original failure crack. After sintering, the old and new coatings are densely bonded to the electrode surface.

[0087] Aging is accelerated by constant current electrolysis (applied current 1A / cm). 2 Electrochemical lifetime testing was conducted using a method that simulates a harsh environment of strong acid and high current density (with 2 mol / L sulfuric acid as the electrolyte solution). Figure 5 The commercial titanium-based iridium-coated electrode in Example 1 under brand new conditions ( Figure 5 As shown in (a) and the repaired electrode in Example 1 (i.e., the commercial titanium-based iridium-coated electrode repaired after its failure) Figure 5 (See Figure b) Comparison of accelerated aging test voltage-time data. A voltage increase of 4V is considered failure. The brand-new commercial titanium-based iridium coated electrode failed after 500 hours of accelerated aging. The repaired coated electrode failed again after 300 hours of accelerated aging. The working time reached 60% of that of the brand-new commercial titanium-based iridium coated electrode, achieving a repair and regeneration effect.

[0088] Figure 6 For a brand new commercial titanium-based iridium-coated electrode ( Figure 6As shown in Figure b), the repaired electrode in Example 1 ( Figure 6 As shown in Figure a), the electrode repaired in Example 1 was subjected to accelerated aging again for 300 hours (i.e., the electrode repaired in Example 1 was subjected to accelerated aging at a current of 1 A / cm² as described above). 2 The electrolyte solution is 2 mol / L sulfuric acid, and constant current electrolysis accelerates aging. (This leads to) failure. Figure 6 (As shown in c) Afterwards, a linear scan voltammetry test was performed (scan rate 1 mV / s). -1 Comparison chart of voltage range 0-1.6V vs. SCE.

[0089] from Figure 6 As can be seen from the results, the electrochemical catalytic performance of the repaired coated electrode in Example 1 is superior to that of the novel commercial titanium-based iridium coated electrode.

[0090] In summary, the coated electrode repaired using the method of this application exhibits good electrochemical activity, but its lifespan is shorter than that of a brand-new commercial electrode. The repair method of this application can effectively extend the electrode's lifespan and improve the utilization rate of the precious metal coating.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for repairing a coated electrode, characterized in that, Includes the following steps: S1. Prepare electrode repair solution; S2. Immerse the coated electrode to be repaired in the electrode repair solution and perform periodic electrodeposition to form a repaired coating on the surface of the coated electrode. S3. Calcine the repaired coated electrode; IrCl3, citric acid, and hydrogen peroxide were added to isopropanol and incubated at 45°C for 8 minutes to obtain the electrode repair solution. The concentrations of IrCl3, citric acid, and hydrogen peroxide were 160 mmol / L, 0.1 mol / L, and 0.5 mol / L, respectively. The periodic electrodeposition was performed using cyclic voltammetry, specifically a three-electrode system: the electrode to be repaired was used as the anode, a titanium electrode as the cathode, and a saturated calomel electrode as the reference electrode. During electrodeposition, the voltage range was controlled to be -0.2V to 0.7V, the scan rate was 30-50 mV / s, and one cycle consisted of the voltage changing from -0.2V to 0.7V and back to -0.2V. One cycle consisted of 15-25 cycles. During electrodeposition, the temperature of the electrode repair solution is controlled at 35~40℃. In the step of calcining the repaired coated electrode, the calcination temperature is 400~500℃ and the time is 10~30min; The coated electrode to be repaired is immersed in an electrode repair solution and subjected to periodic electrodeposition to form a repaired coating on the surface of the electrode. The iridium loading of the repaired coating is 2~3 μg / cm³. 2 ; Repeat steps S2 to S3 5 to 10 times.

2. A coated electrode, characterized in that, The repair was completed using the repair method described in claim 1.

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