Composite anode and preparation method and application thereof

Abstract

The invention relates to the technical field of electrochemistry, in particular to a composite anode and a preparation method and application thereof. An active oxygen evolution material and lead powder are mixed to obtain mixed powder, the mixed powder is laid on a substrate plate, the substrate plate is a lead polar plate or a metal plate grid, an isostatic pressing method or a hot pressing method or a spark plasma sintering method is adopted, the mixed powder is die-cast on the surface of the substrate plate, and the composite anode is obtained. The compact and stable ceramic surface is constructed on the surface of the substrate plate, generation of anode mud in the electrolysis process is reduced, then the tank cleaning frequency is reduced, and in the subsequent plate scraping process, an existing film layer structure cannot be damaged. The composite anode is suitable for the electrolytic process of electrolytic manganese, electrolytic zinc and electrolytic copper, and is also suitable for electrocatalytic degradation of organic matters in organic wastewater. Compared with a traditional lead anode plate, the composite anode does not generate anode mud in the electrolysis process, the service life is longer, and the potential of an oxygen evolution electrode is lower.

Description

Technical Field

[0001] The invention relates to the field of electrochemical technology, in particular to a composite anode and a preparation method and application thereof. Background Art

[0002] Lead anodes are widely used as oxygen evolution electrodes in hydrometallurgy and sewage treatment processes due to their low price, easy molding, and stable operation in sulfuric acid electrolyte.

[0003] For lead anodes, firstly, due to the high density and low strength of lead, the anode is prone to creep deformation when suspended, which may cause short circuit in severe cases, bringing extremely adverse effects on production. In addition, during the electrolysis of lead anodes, the anode surface will eventually be oxidized to lead dioxide; firstly, the lead dioxide film formed on the surface is not dense, but loose and porous, and has weak bonding with the lead matrix, so it is easy to fall off, causing anode loss; in addition, during the electrolysis of zinc and manganese, the electrode surface will also be oxidized to form manganese dioxide anode mud, which will eventually fall off with the lead dioxide film layer, forming useless lead-containing anode mud, causing huge waste of resources. Secondly, water molecules or anions in the electrolyte can easily interact with the lead matrix through the micropores in the film layer, causing the matrix to gradually dissolve, and even enter the cathode, thereby reducing product quality; finally, the catalytic activity of lead dioxide in oxygen evolution is poor, resulting in a high anode overpotential and increased energy consumption.

[0004] In response to the above problems, researchers have proposed many methods for constructing an active layer on the surface of the lead anode. For example, patent CN110129835A proposes a method for pre-electrolyzing a layer of active manganese dioxide on the surface of the lead anode, and patent CN114804301A proposes a method for constructing a layer of hard conductive ceramic on the surface of the lead anode by plasma spraying.

[0005] Researchers have also proposed three functional technology routes for forming new lead alloy electrodes: alloying to improve the function of the electrode, plate rolling technology, and aluminum-based lead anode. For example, patent CN114855225A proposes a method for preparing lead-clad aluminum core composite anodes by reverse osmosis, and patent CN104611609A proposes a method for improving the electrochemical performance of lead anodes by casting and rolling.

[0006] However, during the service of the lead anode, the surface layer constructed above is prone to breakage and fall off due to the continuous erosion of oxygen. In addition, during the electrolysis of manganese and zinc, the anode mud attached to the anode surface needs to be cleaned manually regularly, which can easily scratch the active layer on the surface and render it ineffective. In addition, for ceramic anodes, although they can have better oxygen evolution activity by adding active oxygen evolution materials to reduce the anode potential, the ceramic anode itself is brittle and is not suitable for independent processing into large-sized oxygen evolution electrodes. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned prior art, the present invention provides a composite anode and a preparation method and application thereof. The present invention uses active oxygen evolution material and metal lead powder as raw materials, and forms a metal ceramic layer on a base plate by isostatic pressing, hot pressing or spark plasma sintering to obtain a composite anode. The composite anode of the present invention overcomes the technical problems of poor oxygen evolution activity of lead dioxide on the surface of the lead anode in the prior art during electrolysis, and easy shedding of active particles constructed by the coating method.

[0008] To achieve the above object, the technical solution of the present invention is as follows:

[0009] A method for preparing a composite anode comprises the following steps:

[0010] The lead powder is mixed with an active oxygen evolution material to obtain a mixed powder, wherein the active oxygen evolution material improves the oxygen evolution performance of the composite anode, and the lead powder is used to prepare a lead anode;

[0011] The mixed powder is spread on the base plate, and then the mixed powder and the base plate are compounded together by isostatic pressing, hot pressing or spark plasma sintering to form a metal ceramic layer on the base plate. The ceramic layer is located on both sides of the base plate to obtain a composite anode.

[0012] Preferably, the base plate material is a lead plate or a metal grid. The lead plate is relatively soft in texture. After being compounded with metal powder, it overcomes the mechanical property problem of the lead plate to a certain extent and overcomes the short circuit problem caused by deformation.

[0013] Preferably, the metal grid is selected from one of a lead grid, an aluminum grid, a titanium grid or an iron grid; the lead electrode is selected from a pure lead anode plate or a lead-based alloy anode plate, and in the lead-based alloy anode plate, the alloy component is selected from one or more of Ag, Ca, Sn, Sb, Sr, As, La, and Ce.

[0014] Preferably, the mass ratio of lead powder to active oxygen evolution material is 100:1-50, with lead powder being the main material.

[0015] Preferably, the isostatic pressing method is carried out under the conditions of 50 MPa to 800 MPa for 0.1 h to 12 h.

[0016] Preferably, the conditions of the hot pressing method or spark plasma sintering method are: 100-650° C., 50-800 MPa, and maintained for 0.1 h to 12 h, and the hot pressing also includes hot roller pressing.

[0017] Preferably, the active oxygen evolution material is selected from one or more of ruthenium oxide, iridium oxide, manganese oxide, cobalt oxide, niobium oxide, oxygen-deficient perovskite, AB2O4 type metal oxide or MAX phase material. In the AB2O4 type metal oxide, A is selected from Zn, Co, Cu, B is selected from Fe, Mn or Ni, and the oxygen-deficient perovskite is selected from LaCoO3 or CaMnO3.

[0018] The invention also protects the composite anode prepared by the above preparation method.

[0019] The present invention also protects the use of the composite anode in preparing electrolytic manganese anode material, electrolytic zinc anode material or electrolytic copper anode material, and the embodiments of the present invention provide the application method and results.

[0020] The present invention also protects the use of the composite anode in preparing an electrocatalyst for organic pollutants, and the embodiments of the present invention provide the application method and results.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention mixes an active oxygen evolution material and lead powder to obtain a mixed powder, spreads the mixed powder on a base plate, and adopts isostatic pressing, hot pressing or spark plasma sintering to die-cast the mixed powder on the surface of the base plate to obtain a composite anode. In the ceramic layer formed by the mixed powder, the active oxygen evolution material is used as an active oxide. The active oxide can adjust the ratio of oxygen evolution reaction and manganese ion oxidation reaction when electrolyzed in an electrolyte containing manganese ions such as electrolytic manganese or electrolytic zinc. The active oxygen evolution metal catalyzes the oxygen evolution reaction, so that the oxidation ratio of manganese ions is less, and the manganese dioxide on the surface of the anode is promoted to be deposited as a dense film layer, thereby further protecting the composite anode from being corroded by active oxygen.

[0023] 2. After the electrolysis of the composite anode of the present invention is completed, the electrodeposited manganese dioxide layer can be separated as a basic chemical raw material. Especially compared with the traditional lead anode, its by-product does not contain lead and can be used as a precursor to synthesize battery positive electrode materials.

[0024] 3. The composite electrode of the present invention has good oxygen evolution activity, the surface film layer is not easy to fall off, the composite anode has a longer life, and is more stable in the electrolysis of organic wastewater, so the composite anode of the present invention can also treat organic matter in organic wastewater.

[0025] 4. The present invention inhibits the dissolution of the lead matrix by hot pressing a dense and stable surface layer on the surface of the base plate, and the composite anode electrolysis process does not produce anode mud, reducing the frequency of tank cleaning and extending the service life. The composite anode of the present invention is suitable for the electrolysis process of electrolytic manganese, electrolytic zinc, and electrolytic copper, and compared with the traditional lead anode plate, the active oxygen evolution material has a higher catalytic oxygen evolution activity than the material on the surface of the traditional lead anode, and the oxygen evolution electrode potential is lower.

[0026] 5. Considering the soft texture of the lead anode, the present invention can also use metal grids as reinforcing ribs to strengthen the mechanical properties of the electrode, and construct an active metal ceramic layer on the grid by die-casting to further enhance the oxygen evolution activity of the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flow chart of a method for preparing a composite anode according to an embodiment of the present invention;

[0028] Figure 2 This is a photograph of the anode chamber of the composite anode and the Pb-Ag-Sn-Ca anode plate in Example 1 of the present invention after electrolysis in an electrolytic manganese solution; wherein a is the Pb-Ag-Sn-Ca anode plate, and b is the composite anode;

[0029] Figure 3 This is a photograph of the anode chamber of the composite anode and the Pb-Ag-Sn-Ca anode plate of Example 2 of the present invention after electrolysis in an electrolytic manganese electrolyte; wherein a is the Pb-Ag-Sn-Ca anode plate, and b is the composite anode;

[0030] Figure 4 This is a graph showing the change of anode potential over time after electrolysis of the composite anode and coated titanium anode TI / MnO2 in organic wastewater in Example 3 of the present invention;

[0031] Figure 5 This is a graph showing the change of anode potential over time after electrolysis of the composite anode and coated titanium anode TI / MnO2 in organic wastewater in Example 4 of the present invention;

[0032] Figure 6 The SEM image of the anode surface of the composite anode and the Pb-0.8Ag anode plate of Example 5 of the present invention after electrolysis in an electrolytic zinc electrolyte containing manganese ions; wherein a is the composite anode, and b is the Pb-0.8Ag anode plate;

[0033] Figure 7 The Tafel curve of the composite anode of Example 6 of the present invention and the Pb-0.8Ag anode plate electrolyzed in a solution;

[0034] Figure 8 This is a SEM image of the anode surface after electrolysis of the composite anode of Example 7 of the present invention. DETAILED DESCRIPTION

[0035] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention. The experimental methods described in the embodiments of the present invention are conventional methods unless otherwise specified.

[0036] Considering the problem of poor oxygen evolution activity of lead dioxide on the surface of the lead anode during electrolysis, the present invention mixes active oxygen evolution material in metal lead powder, spreads it on the surface of a base plate, and then uses isostatic pressing, hot pressing or spark plasma sintering to press-cast the powder layer on the surface of the base plate to form a metal ceramic layer on the base plate, thereby obtaining a composite anode; the composite anode uses the base plate as a support to overcome the technical defect that the ceramic layer is relatively brittle, and overcomes the problem of poor oxygen evolution activity of lead dioxide on the surface during electrolysis by adding active oxygen evolution material;

[0037] Considering the problem that active particles constructed by coating methods are easy to fall off, since the metal lead powder and the base plate have good compatibility, the surface ceramic layer is fixed by die casting through isostatic pressing, hot pressing or spark plasma sintering. The active ceramic layer can be well compounded with the base plate, so that the active oxygen evolution material will not fall off, and the obtained electrode has good mechanical properties. In addition, since the active oxygen evolution material is embedded in the ceramic layer, the active oxygen evolution material has a good bonding force with the substrate, which can cope with the subsequent manual cleaning of the electrode anode mud.

[0038] The technical solution of the present invention is further explained by using embodiments below, which are specifically as follows:

[0039] Example 1

[0040] The method for preparing the composite anode comprises the following steps:

[0041] S1. Grind and polish the lead-based alloy anode plate with 1000# sandpaper to obtain a metal lead plate;

[0042] S2. Weigh metal lead powder, ruthenium dioxide and tantalum dioxide powder in a mass ratio of 10:1:0.5, and ball-mill for 12 hours under an inert atmosphere to obtain a mixed powder;

[0043] S3. Spread the mixed powder of step S2 on the metal lead plate of step S1, and put them together in a hot press. Set the hot pressing temperature to 300° C., maintain at 200 MPa for 2 hours, and then cool to room temperature to obtain a composite anode.

[0044] The composite anode provided in this embodiment is used in the electrolytic manganese anode process, and the electrolyte composition is: 15g / L Mn 2+ , 110 g / L ammonium sulfate, pH 7.2, the temperature of the electrolyte is 40°C; the composite anode prepared in Example 1 is cut into cylindrical electrodes, and electrolyzed in an electrolytic manganese electrolyte. For comparison purposes, a Pb-Ag-Sn-Ca anode plate commonly used in the electrolytic manganese industry is taken as a control, placed in the same manganese electrolyte, and electrolyzed for 24 hours under the same electrolysis parameters;

[0045] Figure 2 This is a photo of the anode chamber during electrolysis. It is found that during the electrolysis process, no turbid colloidal substances are produced on the composite anode. 2 The average potential of the composite anode was 2.1V and the average cell voltage was 4.16V after electrolysis for 24 hours, which was 0.4V lower than that of the Pb-Ag-Sn-Ca anode plate. The lead content in the anode mud was less than 0.1%, and the capacity of lithium manganese oxide synthesized with it as a precursor was >116mAh / g, and the cycle life was >700 times.

[0046] Example 2

[0047] The method for preparing the composite anode comprises the following steps:

[0048] S1. Grind and polish the aluminum alloy grid with 1000# sandpaper to obtain an aluminum alloy grid;

[0049] S2. Weigh metal lead powder, ruthenium dioxide and niobium dioxide powder in a mass ratio of 10:1:0.5, and ball-mill them under an inert atmosphere for 8 hours to obtain a mixed powder;

[0050] S3. Spread the mixed powder of step S2 on the aluminum alloy grid of step S1, and put them together in a hot press at 300 MPa for 2 hours to obtain a composite anode.

[0051] The composite anode provided in this embodiment is used in the electrolytic manganese anode process, and the electrolyte composition is: 15g / L Mn 2+ , 110 g / L ammonium sulfate, pH 7.2, the temperature of the electrolyte is 40°C; the composite anode prepared in Example 2 is cut into cylindrical electrodes, and electrolyzed in an electrolytic manganese electrolyte. For comparison purposes, a Pb-Ag-Sn-Ca anode plate commonly used in the electrolytic manganese industry is taken as a control, placed in the same manganese electrolyte, and electrolyzed for 24 hours under the same electrolysis parameters;

[0052] Figure 3 This is a photo of the anode chamber during electrolysis. It is found that during the electrolysis process, no turbid colloidal substances are produced on the composite anode. 2The average potential of the composite anode was 2.1V, the average cell voltage was 4.16V, the average potential of the anode was 2.15V, and the average cell voltage was 4.21V, which was 0.32V lower than that of the Pb-Ag-Sn-Ca anode plate. The lead content in the anode mud was less than 0.1%, and the capacity of lithium manganese oxide synthesized with it as a precursor was >117mAh / g, and the cycle life was >800 times.

[0053] Example 3

[0054] The method for preparing the composite anode comprises the following steps:

[0055] S1. Grind and polish the metal lead plate with 500# sandpaper to obtain a metal lead plate;

[0056] S2. Weigh metal lead powder and manganese dioxide powder in a mass ratio of 10:1.5, and ball-mill them for 12 hours under an inert atmosphere to obtain a mixed powder;

[0057] S3. Spread the mixed powder of step S2 on the metal lead plate of step S1, put them together in a spark plasma sintering furnace, set the hot pressing temperature to 350°C, keep it at 250Mpa for 1 hour, and then cool it to room temperature to obtain a composite anode.

[0058] The composite anode provided in this embodiment is used to degrade organic wastewater. The electrolyte consists of 15 mg / L methylene blue and 50 g / L sodium sulfate solution. The temperature of the electrolyte is 25°C. The composite anode prepared in Example 3 is used as the working electrode, the mercuric sulfate electrode is used as the reference electrode, and the platinum electrode is used as the counter electrode to form a three-electrode system. The three-electrode system is used at 150 A / m 2 The electrolysis experiment of methylene blue was carried out at a current density of Figure 4 The graph of the anode potential of the composite anode and the traditional coated titanium anode TI / MnO2 after electrolysis in the electrolyte shows that the composite anode has better catalytic performance than the coated titanium anode TI / MnO2. On this basis, the present invention also uses an ultraviolet spectrophotometer to measure the degradation rate of methylene blue. The results show that after 9 hours of electrolysis, the degradation rate of methylene blue is 93.1%, and the solution changes from dark blue to light blue, which is almost clear.

[0059] Example 4

[0060] The method for preparing the composite anode comprises the following steps:

[0061] S1. Grind and polish the metal lead plate with 500# sandpaper to obtain a metal lead plate;

[0062] S2. Weigh metal lead powder and manganese dioxide powder in a mass ratio of 10:0.7, and ball-mill them for 16 hours under an inert atmosphere to obtain a mixed powder;

[0063] S3. Spread the mixed powder of step S2 on the metal lead plate of step S1, and put them together in a spark plasma sintering furnace. Set the hot pressing temperature to 300° C., maintain at 350 MPa for 1.5 hours, and then cool to room temperature to obtain a composite anode.

[0064] The composite anode provided in this embodiment is used to degrade organic wastewater. The electrolyte consists of 15 mg / L methylene blue and 50 g / L sodium sulfate solution. The temperature of the electrolyte is 25°C. The composite anode prepared in Example 4 is used as the working electrode, the mercuric sulfate electrode is used as the reference electrode, and the platinum electrode is used as the counter electrode to form a three-electrode system. The three-electrode system is used at 150 A / m 2 The electrolysis experiment of methylene blue was carried out at a current density of Figure 5 The graph of the anode potential of the composite anode and the traditional coated titanium anode TI / MnO2 after electrolysis in the electrolyte shows that the composite anode has better catalytic performance than the coated titanium anode TI / MnO2. On this basis, the present invention also uses an ultraviolet spectrophotometer to measure the degradation rate of methylene blue. The results show that after 8 hours of electrolysis, the degradation rate of methylene blue is 91.1%, and the solution changes from dark blue to light blue, which is almost clear.

[0065] Example 5

[0066] The method for preparing the composite anode comprises the following steps:

[0067] S1, polishing the lead-based alloy anode plate with 800# sandpaper to obtain a metal lead plate;

[0068] S2. Weigh metal lead powder, iridium oxide and tantalum dioxide powder in a mass ratio of 10:1:0.5, and ball-mill them for 12 hours under an inert atmosphere to obtain a mixed powder;

[0069] S3. Place the mixed powder of step S2 and the metal lead plate of step S1 together under a hydraulic press and keep them at 400 MPa for 12 hours to obtain a composite anode.

[0070] The composite anode provided in this embodiment is used in the electrolytic zinc anode process, and the electrolyte composition is: 45g / L Zn 2+ , 3g / L Mn 2+ , 160g / L sulfuric acid, 0.02g / L gelatin, 0.2g / L strontium carbonate, the electrolyte temperature is 40°C, the anode current density is 450A / m 2 , the pole distance is 60mm and the zinc stripping cycle is 24h.

[0071] The composite anode prepared in Example 5 was cut into cylindrical electrodes and electrolyzed in an electrolytic zinc solution. For comparison purposes, a Pb-0.8Ag anode plate commonly used in the electrolytic zinc industry was placed in the same zinc electrolyte and electrolyzed for 24 h under the same electrolysis parameters.

[0072] Determine the amount of dissolved lead and anode mud produced, Figure 6 The SEM images of the anode surface of the composite anode and Pb-0.8Ag anode plate after electrolysis in the electrolyte of electrolytic zinc show that the surface of the composite anode is dense and smooth after electrolysis, while the manganese dioxide on the surface of the traditional Pb-0.8Ag anode plate after electrolysis is spherical particles, indicating that the composite anode can adjust the oxidation path of manganese ions. During the electrolysis process, no colloidal anode mud is produced on the surface of the composite anode, and after the electrolysis is completed, by collecting the anode mud in the electrolyte, the dissolution of the composite anode is reduced by 80.2% and the anode mud is reduced by 90.5% compared with the Pb-0.8Ag anode plate.

[0073] Example 6

[0074] The method for preparing the composite anode comprises the following steps:

[0075] S1. Grind and polish the titanium grid with 800# sandpaper to obtain a titanium grid;

[0076] S2. Weigh metal lead powder and tantalum dioxide powder in a mass ratio of 10:1, and ball-mill them for 10 h under an inert atmosphere to obtain a mixed powder;

[0077] S3. Spread the mixed powder of step S2 on the titanium grid of step S1, and put them together under a hydraulic press. Set the hot pressing temperature to 250° C. and keep it at 600 MPa for 6 hours to obtain a composite anode.

[0078] The composite anode provided in this embodiment is used in the electrolytic zinc anode process, and the electrolyte composition is: 45g / L Zn 2+ , 3g / L Mn 2+ , 160g / L sulfuric acid, 0.02g / L gelatin, 0.2g / L strontium carbonate, the electrolyte temperature is 40°C, the anode current density is 450A / m 2 , the pole distance is 60mm and the zinc stripping cycle is 24h.

[0079] The composite anode prepared in Example 6 was cut into cylindrical electrodes and electrolyzed in an electrolytic zinc solution. For comparison purposes, a Pb-0.8Ag anode plate commonly used in the electrolytic zinc industry was placed in the same zinc electrolyte and electrolyzed for 24 hours under the same electrolysis parameters.

[0080] Determine the amount of dissolved lead and anode mud produced, Figure 7 The anodic potential curves of the composite anode and the Pb-0.8Ag anode plate in the electrolyte of electrolytic zinc are shown in Figure 1. The composite anode has a cell voltage that is 0.31 V lower than that of the Pb-0.8Ag anode plate. After the electrolysis, the anode mud in the electrolyte was collected, and the composite anode had a 85.5% reduction in the amount of corrosion compared to the Pb-0.8Ag anode plate, and a 91.8% reduction in anode mud.

[0081] Example 7

[0082] The method for preparing the composite anode comprises the following steps:

[0083] S1, polishing the lead-based alloy anode plate with 800# sandpaper to obtain a metal lead plate;

[0084] S2. Weigh metal lead powder and manganese trioxide powder in a mass ratio of 10:1.5, and ball-mill them for 12 hours under an inert atmosphere to obtain a mixed powder;

[0085] S3. Spread the mixed powder of step S2 on the metal lead plate of step S1, and put them together in a spark plasma sintering furnace. Set the hot pressing temperature to 400° C., maintain at 150 MPa for 3 hours, and then cool to room temperature to obtain a composite anode.

[0086] The composite anode provided in this embodiment is used in the electrolytic copper anode process, and the electrolyte composition is: 180g / L H2SO4 solution and 45g / L Cu 2+ , the temperature of the electrolyte is 45±0.5℃; the composite anode prepared in Example 7 is cut into cylindrical electrodes and electrolyzed in the electrolyte of electrolytic copper. For comparison, the Pb-0.07%Ca-1.25%Sn anode plate commonly used in the electrolytic copper industry is used as a control, 300A / m 2 The electrolysis was carried out for 48 h at the current density;

[0087] Figure 8 This is a scanning electron microscope image of the composite anode surface after electrolysis. It was found that the average potential of the composite anode was 1.6V, which was 0.2V lower than that of the Pb-0.07%Ca-1.25%Sn anode plate. The overall electrolysis energy consumption was reduced by 18.1%, showing a good energy-saving effect.

[0088] Example 8

[0089] The method for preparing the composite anode comprises the following steps:

[0090] S1. Polish the pure lead anode plate with 800# sandpaper to obtain a metal lead plate;

[0091] S2. Weigh metal lead powder and iridium oxide powder in a mass ratio of 100:1, and ball-mill them for 12 hours under an inert atmosphere to obtain a mixed powder;

[0092] S3. Spread the mixed powder of step S2 on the metal lead plate of step S1, and put them together in a spark plasma sintering furnace. Set the hot pressing temperature to 650° C., maintain it at 50 MPa for 0.1 h, and then cool it to room temperature to obtain a composite anode.

[0093] Example 9

[0094] The method for preparing the composite anode comprises the following steps:

[0095] S1. Grind and polish the aluminum grid with 800# sandpaper to obtain a metal aluminum plate;

[0096] S2. Weigh metal lead powder and LaCoO3 powder in a mass ratio of 100:50, and ball-mill them for 12 h under an inert atmosphere to obtain a mixed powder;

[0097] S3. Spread the mixed powder of step S2 on the metal aluminum plate of step S1, and put them together in a hot press. Set the hot pressing temperature to 100° C., maintain at 800 MPa for 12 hours, and then cool to room temperature to obtain a composite anode.

[0098] Example 10

[0099] The method for preparing the composite anode comprises the following steps:

[0100] S1. Grind and polish the iron grid with 800# sandpaper to obtain a metal iron plate;

[0101] S2. Weigh metal lead powder and ZnFe2O4 powder in a mass ratio of 100:25, and ball-mill them for 12 hours under an inert atmosphere to obtain a mixed powder;

[0102] S3. Spread the mixed powder of step S2 on the metal iron plate of step S1, and put them together in a hot press, keep it at 800 MPa for 0.1 h, to obtain a composite anode.

[0103] Embodiment 11

[0104] The method for preparing the composite anode comprises the following steps:

[0105] S1. Grind and polish the iron grid with 800# sandpaper to obtain a metal iron plate;

[0106] S2. Weigh metal lead powder and MAX phase material powder in a mass ratio of 100:40, and ball-mill them for 12 h under an inert atmosphere to obtain a mixed powder;

[0107] S3. Spread the mixed powder of step S2 on the metal iron plate of step S1, and put them together in a hot press, keep them at 50 MPa for 12 hours, to obtain a composite anode.

[0108] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a composite anode, characterized in that: The steps include: Mixing lead powder with active oxygen evolution material to obtain mixed powder; The mixed powder is spread on a base plate, and then the mixed powder and the base plate are compounded together by isostatic pressing, hot pressing or spark plasma sintering to obtain a composite anode.

2. The method for preparing a composite anode according to claim 1, characterized in that: The base plate is a lead plate or a metal grid.

3. The method for preparing a composite anode according to claim 2, characterized in that: The lead plate is selected from pure lead anode plate or lead-based alloy anode plate. In the lead-based alloy anode plate, the alloy component is selected from one or more of Ag, Ca, Sn, Sb, Sr, As, La, and Ce; the metal grid is selected from one of lead grid, aluminum grid, titanium grid, or iron grid.

4. The method for preparing a composite anode according to claim 1, characterized in that: The mass ratio of lead powder to active oxygen evolution material is 100:1-50.

5. The method for preparing a composite anode according to claim 1, characterized in that: The conditions of the isostatic pressing method are: pressing at 50Mpa to 800Mpa for 0.1h to 12h.

6. The method for preparing a composite anode according to claim 1, characterized in that: The conditions of the hot pressing method or spark plasma sintering method are: 100-650° C., 50-800 MPa, and maintaining for 0.1 h to 12 h.

7. The method for preparing a composite anode according to claim 1, characterized in that: The active oxygen evolution material is selected from one or more of ruthenium oxide, iridium oxide, manganese oxide, cobalt oxide, niobium oxide, oxygen-deficient perovskite, AB2O4 metal oxide or MAX phase material.

8. A composite anode prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the composite anode according to claim 8 in preparing electrolytic manganese anode material, electrolytic zinc anode material or electrolytic copper anode material.

10. Use of the composite anode according to claim 8 in preparing an electrocatalyst for organic pollutants.

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