Self-cleaning electrochemical descaling cathode material and preparation method and application thereof
By preparing porous micro/nano nickel arrays and polymer layers on electrochemical descaling cathode materials, the problem of efficiency reduction caused by cathode scaling was solved, achieving a self-cleaning effect and improving the stability and efficiency of electrochemical descaling.
Patent Information
- Application Number
- CN202511703339.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-01-09
AI Technical Summary
Existing electrochemical descaling cathode materials are prone to scaling during the scaling process, which leads to a reduction in the effective reaction area and a decrease in electrolysis efficiency, making it difficult to achieve long-term stable and efficient operation.
A porous micro/nano nickel array and a polymer layer were prepared on a metal substrate by electrodeposition to construct a composite cathode material. The porous micro/nano nickel array was used as an OH- transporter to separate the generation of OH- and the scaling and precipitation reaction of Mg2+ and Ca2+. The smooth surface was used to reduce the adhesion of scale and promote spontaneous shedding.
It improves the self-cleaning ability of the cathode, reduces the cathode deactivation rate and energy consumption, and ensures the continuous and efficient operation of the descaling process.
Smart Images
Figure CN121292589A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high-performance cathode material preparation technology, and in particular to a self-cleaning electrochemical descaling cathode material, its preparation method, and its application. Background Technology
[0002] Electrochemical descaling technology is a highly efficient active water treatment technology. Its core advantage lies in its ability to directly separate and extract scale-forming ions such as calcium and magnesium from water, removing them through scale deposition. This significantly reduces wastewater discharge and system makeup water volume, resulting in substantial water-saving benefits. The system mainly consists of an anode, a cathode, and a power supply. During electrolysis, the anode generates various highly oxidizing active substances, effectively inhibiting the growth of microorganisms and algae in the circulating cooling water system and also possessing a certain bactericidal effect. The cathode surface forms a localized high-alkalinity zone through an electrochemical reduction reaction. When water containing calcium and magnesium ions flows through this zone, it generates precipitates such as calcium carbonate and magnesium hydroxide, which are adsorbed onto the cathode surface. Regular cleaning removes these precipitates in solid form, thus achieving descaling. Throughout the entire descaling process, the cathode reaction is the key step in achieving highly efficient descaling.
[0003] However, in actual industrial operation, scale buildup easily occurs on the cathode surface, causing problems such as reduced effective reaction area, decreased electrolysis efficiency, and impaired hydrogen mass transfer. This leads to a gradual decline in descaling performance and even cathode deactivation, severely restricting the long-term stable application of descaling technology. The cathode reaction essentially involves two competing processes: alkalinity generation and scale deposition. The continuous accumulation of scale hinders mass transfer and reaction processes, resulting in a sustained decrease in descaling efficiency.
[0004] To address the aforementioned issues, several improvement strategies have been proposed in international research. For example, employing multi-stage reactors with a serpentine flow field structure to increase the specific surface area and reaction interface has improved ion removal efficiency to some extent. However, such structural improvements also increase the difficulty of cathode cleaning and do not fundamentally solve the problem of scale deposition on the cathode surface, making it difficult to achieve continuous and efficient operation.
[0005] In view of this, it is necessary to design an improved self-cleaning electrochemical descaling cathode material, its preparation method, and its application to solve the above problems. Summary of the Invention
[0006] The purpose of this invention is to provide a self-cleaning electrochemical descaling cathode material, its preparation method, and its application.
[0007] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a method for preparing a self-cleaning electrochemical descaling cathode material, comprising the following steps:
[0008] S1. A porous micro / nano nickel array is prepared on one side of a pretreated metal substrate by electrodeposition, and the porous micro / nano nickel array is electrochemically activated to obtain a support layer on one side of the metal substrate.
[0009] The steps for preparing porous micro / nano nickel arrays by electrodeposition are as follows: using a metal substrate as the cathode plate and a noble metal or its alloy as the anode plate, electrodeposit for 40-60 min in an electrodeposition solution at a current density of 45-50 mA / cm².
[0010] S2. Deposit the polymer solution onto the surface of the support layer in step S1 to obtain the polymer layer.
[0011] Preferably, in step S1, the electrodeposition solution is prepared as follows: nickel iminosulfate tetrahydrate, phosphorous acid, nickel chloride hexahydrate, and boric acid are dissolved in water at a mass ratio of 21:1:1:1.25. The addition rule for nickel iminosulfate is: 250-280 g of nickel iminosulfate is added to every 1 L of water, followed by sodium molybdate dihydrate. The mixture is then stirred until homogeneous to obtain the electrodeposition solution. The mass fraction of sodium molybdate dihydrate in the electrodeposition solution is 2-3%.
[0012] Preferably, in step S1, the electrochemical activation of the porous micro / nano nickel array is carried out according to the following steps: the porous micro / nano nickel array is used as the working electrode, 1M KOH is used as the electrolyte, a forward current of 30 mA-50 mA is applied for 300 s, and then the current is switched to a reverse current of -30 mA to -50 mA for 300 s. One complete current switching cycle is one activation cycle, and the activation cycle is 15-20.
[0013] Preferably, in step S2, the polymer solution is a PBI solution, which is obtained by dissolving PBI in ethanol, and the mass ratio of PBI to ethanol is 1:100.
[0014] Preferably, in step S2, the deposition process is carried out by an ultrasonic spraying device, and the specific process parameters are: frequency of 60-80 kHz, atomization flow rate of 5-8 mL / min, air pressure of 0.03-0.05 MPa, and coating thickness ≤30µm.
[0015] Preferably, in step S1, the pretreatment of the metal substrate includes sanding and ultrasonic treatment.
[0016] Secondly, the present invention provides a self-cleaning electrochemical descaling cathode material.
[0017] Thirdly, the present invention provides a composite cathode, comprising:
[0018] A polymer layer, which serves as the intermediate layer of the composite cathode;
[0019] Two support layers are respectively disposed on two sides of the polymer layer;
[0020] Two metal substrates, each of which is tightly bonded to the support layer.
[0021] Fourthly, the present invention provides an application of a self-cleaning electrochemical descaling cathode material in electrochemical descaling.
[0022] The beneficial effects of this invention are:
[0023] The self-cleaning electrochemical descaling cathode material provided by this invention is prepared by sequentially fabricating a porous micro / nano nickel array and a polymer layer on a metal substrate. When used for electrochemical descaling, the porous micro / nano nickel array in this cathode material can act as an "OH" electrode. - The "transporter" generates alkalinity and provides a pathway for ion diffusion, carrying OH- - The formation and Mg 2+ Ca 2+ The scaling and precipitation reaction is separated into the porous nickel micro / nano array region of the composite cathode and the smooth stainless steel outer side to create a synergistic effect of induced crystallization and reduced scaling. The smooth surface reduces the scaling adhesion, causing spontaneous scaling to fall off, while ensuring the continuous generation of precipitates, thus reducing the cathode deactivation rate and energy consumption. Attached Figure Description
[0024] Figure 1 This is a microstructure diagram of the porous micro / nano nickel array prepared in Example 1 of the present invention;
[0025] Figure 2 This is a schematic diagram of the preparation process of the self-cleaning electrochemical descaling cathode material proposed in this invention;
[0026] Figure 3 This is a schematic diagram illustrating the working principle of the composite cathode in Embodiment 1 of the present invention;
[0027] Figure 4 The microstructure of the cathode precipitate in the electrochemical descaling experiments of Example 1 and Comparative Example 1 of this invention is shown. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.
[0030] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0031] On one hand, the present invention provides a method for preparing a self-cleaning electrochemical descaling cathode material, comprising the following steps:
[0032] S1. A porous micro / nano nickel array was prepared on one side of a pretreated metal substrate using an electrodeposition method. The porous micro / nano nickel array is characterized by: ordered arrangement of multiple layers of pores, an average pore size of 500 nm-1 mm, and a pore density of approximately 10. 10 The porous micro / nano nickel array was electrochemically activated to form a support layer on one side of the metal substrate;
[0033] S2. Deposit the polymer solution onto the surface of the support layer in step S1 to obtain the polymer layer.
[0034] In some embodiments, in step S1, the pretreatment of the metal substrate is performed as follows: the metal substrate is polished sequentially using #240, #800, #1000, and #1200 sandpaper, and then ultrasonically treated with dilute hydrochloric acid, deionized water, and acetone, respectively. Each ultrasonic treatment lasts for 15 minutes, and the pretreated metal substrate is obtained.
[0035] In some embodiments, the step of preparing porous micro / nano nickel arrays by electrodeposition in step S1 is as follows: using a metal substrate as the cathode and a noble metal or its alloy as the anode, electrodeposition is performed for 40-60 min at a current density of 45-50 mA / cm² to prepare porous micro / nano nickel arrays. Specifically, the electrodeposition solution is prepared as follows: nickel iminosulfate tetrahydrate (Ni(SO3NH2)2·4H2O), phosphorous acid (H3PO3), nickel chloride hexahydrate (NiCl2·6H2O), and boric acid (H3BO3) are dissolved in water at a mass ratio of 21:1:1:1.25. The addition rule for nickel iminosulfate is: 250-280 g of nickel iminosulfate is added to every 1 L of water, followed by sodium molybdate dihydrate (Na2MoO4·2H2O), and the mixture is stirred evenly to obtain the electrodeposition solution. The mass fraction of sodium molybdate dihydrate in the electrodeposition solution is 2-3%.
[0036] Furthermore, the electrochemical activation of the porous micro / nano nickel array is carried out according to the following steps: the above nickel array is used as the working electrode, and 1M KOH is used as the electrolyte. First, a forward current of 30 mA-50 mA is applied for 300 s, and then a reverse current of -30 mA to -50 mA is applied for 300 s. One complete current switching cycle is one activation cycle, and the activation cycle is 15-20, to activate the nickel array to induce the formation of Ni(III).
[0037] In some embodiments, in step S2, the polymer solution is preferably a PBI solution, which is obtained by dissolving PBI in ethanol, with a mass ratio of 1:100.
[0038] In some embodiments, in step S2, the deposition process is carried out using an ultrasonic spraying device with the following specific process parameters: frequency of 60-80 kHz, atomization flow rate of 5-8 mL / min, air pressure of 0.03-0.05 MPa, and coating thickness ≤30µm. It should be noted that in other embodiments, other devices may be used to complete the deposition process; the specific method can be selected as needed.
[0039] On the other hand, the present invention provides a composite cathode comprising:
[0040] The polymer layer serves as the intermediate layer of the composite cathode;
[0041] Two support layers are respectively located on two sides of the polymer layer;
[0042] Two metal substrates, with each metal substrate tightly bonded to the support layer.
[0043] The following specific embodiments further illustrate the self-cleaning electrochemical descaling cathode material, its preparation method, and its application proposed in this invention:
[0044] Example 1
[0045] This embodiment provides a method for preparing a self-cleaning electrochemical descaling cathode material, including the following steps:
[0046] S1. Dissolve 250 g of nickel iminosulfate tetrahydrate, 12 g of phosphorous acid, 12 g of nickel chloride hexahydrate and 15 g of boric acid in 1 L of deionized water, then add 25 g of sodium molybdate dihydrate and mix well to obtain the electrolyte.
[0047] A three-electrode system was used, with a stainless steel plate (length × width = 3cm × 5cm) as the cathode, a platinum sheet as the anode, and a saturated calomel electrode as the reference electrode. The system was operated in an electrolyte at a current density of 50 mA / cm². 2Electrodeposition was performed for 40 minutes to create a porous micro / nano nickel array on one side of a stainless steel plate. It should be noted that the stainless steel plate needs to be pretreated before electrodeposition. The specific pretreatment steps are as follows: After polishing the stainless steel plate with #240, #800, #1000, and #1200 sandpaper in sequence, the polished stainless steel plate was ultrasonically treated with dilute hydrochloric acid, deionized water, and acetone, respectively. Each ultrasonic treatment lasted 15 minutes, resulting in a pretreated stainless steel plate. The purpose of this process is to remove oxides and impurities from the surface of the stainless steel plate. The concentration and volume of the solution used in the ultrasonic treatment process can be selected as needed, as long as it meets the requirements of the actual application; this is not a limitation here.
[0048] Microstructure diagram of porous micro / nano nickel array as shown in Figure Figure 1 As shown, where, Figure 1 Figure a in the image is a scanning electron microscope image of a stainless steel substrate. Figure 1 Figure b shows the microstructure of the self-supporting porous micro / nano nickel array deposited on a stainless steel substrate. Figure 1 Figure c in the image is a scanning electron microscope image of a further magnified portion of the microstructure in Figure b. From... Figure 1 It can be seen that the porous micro / nano nickel array is characterized by an ordered arrangement of multiple pores, possessing abundant specific surface area and active sites. The dendritic microstructure is conducive to OH... - And the diffusion and mass transfer of hydrogen.
[0049] After electrodeposition, the electrodes were rinsed clean, and the three-electrode system was continued. The electrolyte was replaced with 1 M KOH, and a current of ±30 mA was applied to activate the porous micro / nano nickel array prepared by electrodeposition. Specifically, a forward current of 30 mA was applied for 300 s, followed by a reverse current of -30 mA for 300 s, which was recorded as one activation cycle. Twenty activation cycles were performed. After activation, the electrodes were rinsed clean and then dried in a vacuum oven at 50 °C for 1 h. The catalyst loading was 2.5 mg / cm³. 2 That is, a support layer is made on one side of the stainless steel plate;
[0050] S2. Dissolve 10 g of polybenzimidazole in 1 L of ethanol (analytical grade) and spray it directly onto the surface of the above support layer using an ultrasonic spraying device to form a polymer layer on the surface of the support layer, thus obtaining the cathode material.
[0051] The stainless steel plate with a support layer formed on its surface obtained in step S1 is assembled with the cathode material containing both a support layer and a polymer layer obtained in step S2 to obtain a composite cathode. The assembly process ensures that the polymer layer serves as the intermediate layer of the composite cathode. A schematic diagram of its fabrication is shown below. Figure 2 As shown.
[0052] The composite cathode was applied to simulated circulating cooling water descaling: 15 mol CaCl2 and 30 mol NaHCO3 were dissolved in 600 mL of tap water and allowed to stand for 1 h before being used as the circulating cooling water to simulate the electrochemical descaling process. The composite cathode was used as the cathode, and a commercially available ruthenium-coated titanium electrode (length × width = 5 cm × 5 cm) was used as the anode. A constant current of 5 mA / cm was applied using a DC power supply. 2 The circulating cooling water was circulated by a peristaltic pump at a water inlet rate of 400 mL / min. After 3 hours of electrolysis, the test was stopped, and the difference in cathode weight before and after the experiment was recorded as the scale weight. The sedimentation rate was calculated to be 415.1 g / (m³). 2 •h), and observe the microstructure of the scale layer on the cathode, such as Figure 4 As shown in Figure a, the sedimentary layer exhibits a multi-level branching morphology.
[0053] The working principle of the composite cathode in the above applications is as follows: Figure 3 As shown, specifically, its working mechanism is as follows: In the initial stage of electrochemical descaling of circulating cooling water, the cathode preferentially undergoes a reaction (1), and OH is generated by electrolysis of water. - The reaction mainly occurs on the outer layer of the cathode, i.e., the outside of the stainless steel layer, where there is a concentration gradient of OH. - The solution diffuses to the outside of the cathode and the inner layer of the cathode. Under the action of the electric field, calcium and magnesium ions in the circulating cooling water migrate to the surface of the outer layer of the cathode and preferentially undergo precipitation reactions, as shown in equations (2) and (3). As the descaling process proceeds, the outer layer is gradually covered by scale. The transition metal Ni(III) with high oxidation potential in the cathode mediates OH- - The generation of OH occurs at this time in the inner layer of the cathode. - The reaction (4) gradually became dominant. A large amount of OH... - Ions diffuse from the inner layer to the solution outside the cathode, while calcium and magnesium ions migrate from the external solution to the inner layer of the cathode. These ions come into contact and react near the outer layer of the cathode. More importantly, the scale preferentially deposited on the outer layer forms a nucleation surface, accelerating subsequent scale deposition. This is because the self-supporting porous micro / nano layers of the cathode material act as "OH- transporters" during the descaling process, greatly reducing the generation of OH-. - The reaction and Mg 2+ Ca 2+ Competition between scaling and precipitation reactions, thereby generating OH through the electrolysis of water in the outer layer of the cathode and the reduction of Ni(Ⅲ) by the porous micro / nano nickel array in the inner layer. - The concentration gradient establishes a sustained alkalinity diffusion channel, creating a self-cooperative effect that induces the continuous migration of calcium and magnesium ions, which preferentially deposit on the smooth outer surface of stainless steel due to the nucleation effect. In other words, by generating OH... - The reaction and Mg2+ Ca 2+ The scaling and precipitation reaction is separated into the porous nickel micro / nano array region of the composite cathode and the smooth outer surface of stainless steel to create a synergistic effect; secondly, it also ensures the continuous production of OH in the cathode region. - The formation of a highly alkaline environment results in scale deposition primarily occurring on the smooth outer layer of the cathode stainless steel during the entire descaling process of the circulating cooling water. The scale preferentially deposited on the outer layer accelerates subsequent scale deposition in the later stages of the process. The spontaneous scaling and shedding of the smooth stainless steel surface reduces the cathode deactivation rate and energy consumption.
[0054] (1) (2) ;
[0055] (3) (4) .
[0056] Example 2
[0057] This embodiment provides a method for preparing a self-cleaning electrochemical descaling cathode material, including the following steps:
[0058] S1. Dissolve 1250 g of nickel iminosulfate tetrahydrate, 60 g of phosphorous acid, 60 g of nickel chloride hexahydrate and 75 g of boric acid in 5 L of deionized water, then add 125 g of sodium molybdate dihydrate and mix well to obtain the electrolyte.
[0059] A three-electrode system was used, with a stainless steel plate (length × width = 10cm × 5cm) as the cathode, and a ruthenium-titanium coated substrate (length × width = 10cm × 10cm) as the anode and reference electrode. The system was operated in an electrolyte at a current density of 45 mA / cm². 2 Electrodeposition was performed for 50 minutes to fabricate a porous micro / nano nickel array on one side of a stainless steel plate.
[0060] After electrodeposition, the electrodes were rinsed clean, and the three-electrode system was continued. The electrolyte was replaced with 1 M KOH, and a current of ±30 mA was applied to activate the porous micro / nano nickel array prepared by electrodeposition. First, a current of 30 mA was applied for 300 s, and then the current was switched to -30 mA for 300 s. This was recorded as one activation cycle, and 20 activation cycles were performed.
[0061] After activation, the electrode was rinsed clean and then dried in a vacuum oven at 50°C for 1 hour, with a catalyst loading of 2.5 mg / cm³. 2 That is, a support layer is made on one side of the stainless steel plate;
[0062] S2. Dissolve 15g of polybenzimidazole in 1.5L of ethanol (analytical grade) and spray it directly onto the surface of the above support layer using an ultrasonic spraying device to form a polymer layer on the surface of the support layer, thus obtaining the cathode material.
[0063] The stainless steel plate with a support layer formed on its surface obtained in step S1 is assembled with the cathode material containing both a support layer and a polymer layer obtained in step S2 to obtain a composite cathode.
[0064] The composite cathode was applied to descaling a simulated circulating cooling water system: 12.5 L of simulated circulating cooling water was prepared, with 1.5 g / L CaCl2, 0.5 g / L MgSO4, and 0.8 g / L NaHCO3 fully dissolved in deionized water. The composite cathode was used as the cathode, and a commercially available ruthenium-coated titanium electrode (RuO2 + IrO2 precious metal content 8-25 g / m) was used as the anode. 2 (Length x Width = 5cm x 5cm, purchased from Taobao) Connect to a DC power supply with a constant current of 5 mA / cm². 2 The water hardness at the outlet was measured every hour. After 5 hours, the stable value was below 100 mg / L. The test was stopped after 12 hours of electrolysis. The precipitate on the cathode surface was knocked off, collected, and weighed. The precipitate in the water was also filtered and weighed. According to... The calculated total sedimentation rate is 822.4 g / (m²). 2 •h). The mass ratio of precipitate on the cathode surface to precipitate in the water is 1:6, indicating that the cathode has a good self-detachment effect.
[0065] Examples 3 to 6
[0066] The only difference between Examples 3 to 6 and Example 1 is that the electrodeposition parameters in step S1 are different from those in Example 1; the remaining experimental parameters are the same as in Example 1 and will not be repeated here. The electrodeposition parameter settings for Examples 1 and Examples 3 to 6 are shown in Table 1. The data in the table show that the catalyst loading increases with the increase of the electrodeposition current density. When the deposition current density is 45-50 mA / cm²... 2 The optimal deposition rate of the prepared descaling cathode is achieved when the current density is at the specified level. Insufficient current density leads to inadequate catalyst loading, making it difficult to continuously generate alkalinity and resulting in a low deposition rate. Conversely, excessive current density leads to overloading of the catalyst, affecting the exposure of active sites and the effective diffusion of ions, thus resulting in poor descaling and deposition effects.
[0067] Table 1. Experimental results of cathode materials obtained under simulated circulating cooling water descaling under the electrodeposition parameter settings and corresponding conditions in Examples 1, 3 to 6.
[0068]
[0069] Comparative Example 1
[0070] The only difference between Comparative Example 1 and Example 1 is that no support layer and polymer layer are prepared on the surface of the stainless steel plate. Instead, the pretreated stainless steel plate is directly used as the cathode to simulate the descaling of circulating cooling water. The specific application process is the same as that in Example 1, and will not be repeated here.
[0071] The precipitation rate under these conditions was calculated to be 231.5 g / (m²). 2 •h), and observe the microstructure of the scale layer on the cathode, such as Figure 4 As shown in Figure b, the results show that the sedimentary layer is in a tight clustered state.
[0072] Comparative Example 2
[0073] The only difference between Comparative Example 1 and Example 1 is that no support layer and polymer layer are prepared on the surface of the stainless steel plate. Instead, the pretreated stainless steel plate is directly used as the cathode to simulate the descaling of circulating cooling water. The specific application process is the same as that in Example 2, and will not be repeated here.
[0074] The water hardness at the outlet was measured hourly. After 5 hours, the outlet hardness was 1355 mg / L. Electrolysis was stopped after 12 hours. After stopping the test, the precipitate on the cathode surface was knocked off, collected, and weighed. The sedimentation rate was calculated to be 438.8 g / (m³). 2 No obvious precipitation or peeling was observed.
[0075] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing a self-cleaning electrochemical descaling cathode material, characterized in that, Includes the following steps: S1. A porous micro / nano nickel array is prepared on one side of a pretreated metal substrate by electrodeposition, and the porous micro / nano nickel array is electrochemically activated to obtain a support layer on one side of the metal substrate. The steps for preparing porous micro / nano nickel arrays by electrodeposition are as follows: using a metal substrate as the cathode plate and a noble metal or its alloy as the anode plate, electrodeposit for 40-60 min in an electrodeposition solution at a current density of 45-50 mA / cm². S2. Deposit the polymer solution onto the surface of the support layer in step S1 to obtain the polymer layer.
2. The preparation method according to claim 1, characterized in that, In step S1, the electrodeposition solution is prepared as follows: nickel iminosulfate tetrahydrate, phosphorous acid, nickel chloride hexahydrate, and boric acid are dissolved in water at a mass ratio of 21:1:1:1.
25. The addition rule for nickel iminosulfate is: 250-280 g of nickel iminosulfate is added to every 1 L of water, followed by sodium molybdate dihydrate. The mixture is then stirred until homogeneous to obtain the electrodeposition solution. The mass fraction of sodium molybdate dihydrate in the electrodeposition solution is 2-3%.
3. The preparation method according to claim 1, characterized in that, In step S1, the electrochemical activation of the porous micro / nano nickel array is carried out according to the following steps: the porous micro / nano nickel array is used as the working electrode, 1M KOH is used as the electrolyte, a forward current of 30 mA-50 mA is applied for 300s, and then the reverse current of -30 mA to -50 mA is applied for 300s. One complete current switching cycle is one activation cycle, and the activation cycle is 15-20.
4. The preparation method according to claim 1, characterized in that, In step S2, the polymer solution is a PBI solution, which is obtained by dissolving PBI in ethanol, with a mass ratio of PBI to ethanol of 1:
100.
5. The preparation method according to claim 1, characterized in that, In step S2, the deposition process is carried out by an ultrasonic spraying device, with the following specific process parameters: frequency of 60-80kHz, atomization flow rate of 5-8 mL / min, air pressure of 0.03-0.05 MPa, and coating thickness ≤30µm.
6. The preparation method according to claim 1, characterized in that, In step S1, the pretreatment of the metal substrate includes sanding and ultrasonic treatment.
7. A self-cleaning electrochemical descaling cathode material prepared by any one of claims 1-6.
8. A composite cathode, characterized in that, include: A polymer layer, which serves as the intermediate layer of the composite cathode; Two support layers are respectively disposed on two sides of the polymer layer; Two metal substrates, each of which is tightly bonded to the support layer, wherein the support layer and the metal substrate are prepared by any one of claims 1-6.
9. The application of a self-cleaning electrochemical descaling cathode material prepared by any one of claims 1-6 or the self-cleaning electrochemical descaling cathode material of claim 7 in electrochemical descaling.