A titanium alloy anode plate and its preparation method

Abstract

The present invention provides a titanium alloy anode plate and a preparation method thereof, belonging to the technical field of anode plates. Ti powder and Mn powder are mixed, ball-milled, and subjected to plasma spheroidization treatment to obtain spherical TiMn alloy powder, which is flame-sprayed on the surface of a titanium plate, followed by gradient manganese infiltration. After surface treatment, copper nanowire-deposited graphene@spherical TiMn alloy powder is evenly sprayed, dried, and a titanium alloy anode plate is prepared. The titanium alloy anode plate prepared by the present invention can be used in the production of electrolytic manganese dioxide, has anti-passivation performance, and under a current density of 100 A / m<supgt;2< / supgt> and normal industrial electrolysis conditions, the cell voltage can be stably within 2.3 - 2.4 volts. The product adheres well to the anode, without cracking or detachment phenomena, overcoming the defects of existing industrial anodes, and is an ideal anode for electrolytic manganese dioxide.

Description

Technical Field

[0001] The present invention relates to the technical field of anode plates, and particularly relates to a titanium alloy anode plate and a preparation method thereof. Background Art

[0002] Electrolytic MnO 2 Compared with chemical MnO 2 and natural manganese dioxide, it has the characteristics of high purity, strong adsorption, strong moisture absorption and oxidation, high activity, excellent discharge performance, etc., and is a key component of the positive electrode materials of modern alkaline batteries, lithium batteries and sodium batteries. Usually, the activity of MnO 2 increases with the increase of the crystal water it contains. The crystal water can promote the diffusion of protons in the solid phase. γ-MnO 2 has the best activity among various crystal forms of MnO 2 .

[0003] Currently, the main method for producing electrolytic MnO 2 is the high-temperature electrolysis method, which means that at a high temperature (96 - 98 °C) and a certain current density, the electrolyte of the MnSO 4 -H 2 SO 4 system is electrolyzed, so that Mn 2+ undergoes a redox reaction on the anode to precipitate and deposit MnO 2 . After the MnO 2 is deposited to a certain thickness, the anode can be taken out of the tank, and the MnO 2 is mechanically peeled off. In order to enable Mn 2+ to overcome the reverse potential and diffuse to the anode, which is beneficial to the precipitation of MnO 2 to obtain γ-MnO 2 , the industry expects to develop in the direction of high acid and high current. However, the current anode materials have relatively serious passivation and corrosion under high acid and high current conditions, which restricts the development of the electrolytic manganese dioxide (EMD) industry. In addition, there is a large loss of the anode during the mechanical peeling of MnO 2 , and the anode is required to have high strength and ductility.

[0004] Currently, the mainstream solution in the EMD industry to the problem that anode materials are prone to passivation and corrosion in high current density and high acidity electrolysis environments is to use Ti-based TiMn coated anodes. The reason for the easy passivation of pure Ti is that its oxide has extremely poor conductivity, while the oxide of Mn has better conductivity. Therefore, increasing the Mn content in the TiMn coating can make its passivation resistance higher. Compared with pure titanium anodes, Ti-based TiMn coated anodes not only retain the excellent comprehensive mechanical properties provided by the pure Ti matrix, but also have better wettability, lower cell voltage, and better passivation resistance.

[0005] At present, the main method for preparing Ti-based TiMn coating anodes is the high-temperature manganese infiltration process. Although this process alleviates the passivation corrosion of the anode to a certain extent, there are still defects. For example, the Mn content on the surface of the anode plate is limited, resulting in limited performance of the finally obtained anode plate. Moreover, Mn is prone to volatilization and diffusion under high vacuum and high temperature, the manganese infiltration efficiency is low, and the manganese source is seriously wasted. In addition, under high-temperature conditions, the α-Ti grains in the Ti matrix are coarse, β-titanium transformation occurs, and a lamellar β-titanium transformation structure is obtained after cooling, resulting in an increase in the brittleness of the Ti plate. This anode is prone to fracture during the production of mechanically peeled manganese dioxide.

[0006] With the rapid development of new energy, there are requirements for improving quality and saving energy for electrolytic MnO₂, which is an important raw material for batteries. At present, the anode materials used in electrolytic MnO₂ are difficult to operate under conditions of high acidity and large current, resulting in low electrolysis efficiency. The crystal form regulation range of MnO₂ is small, the purity is low, and the performance regulation of electrolytic MnO₂ is narrow. Therefore, there is an urgent need to develop new anode materials to improve the comprehensive performance of anode materials and efficiently produce high-quality electrolytic MnO₂ to boost the development of the new energy industry. 2 At present, the anode materials used in electrolytic MnO₂ 2 are difficult to carry out under the conditions of high acidity and large current, resulting in low electrolysis efficiency. 2 The crystal form regulation range of MnO₂ is small, the purity is low, 2 and the performance regulation of electrolytic MnO₂ is narrow. Therefore, there is an urgent need to develop new anode materials to improve the comprehensive performance of anode materials and efficiently produce high-quality electrolytic MnO₂ 2 to boost the development of the new energy industry. Summary of the Invention

[0007] The purpose of the present invention is to provide a titanium alloy anode plate and its preparation method for the production of electrolytic manganese dioxide, which has anti-passivation performance. At a current density of 100 A / m², under normal industrial electrolysis conditions, the cell voltage can be stabilized within 2.3 - 2.4 volts. The product adheres well to the anode, without cracking or detachment phenomena, overcoming the defects of existing industrial anodes, and is an ideal anode for electrolytic manganese dioxide. 2 The technical solution of the present invention is realized as follows:

[0008] The present invention provides a preparation method of a titanium alloy anode plate, which mixes Ti powder and Mn powder, performs ball milling and plasma spheroidization treatment to obtain spherical TiMn alloy powder, sprays it on the surface of a titanium plate by flame spraying, performs gradient manganese infiltration, and after surface treatment, uniformly sprays copper nanowire-deposited graphene @ spherical TiMn alloy powder and dries it to prepare the titanium alloy anode plate.

[0009] As a further improvement of the present invention, it includes the following steps:

[0010] S1. Plasma spheroidization treatment: Mix Ti powder and Mn powder, perform ball milling under inert gas protection, and perform plasma spheroidization treatment on the product to obtain spherical TiMn alloy powder;

[0011] S1. Plasma spheroidization treatment: Mix Ti powder and Mn powder, ball mill under inert gas protection, and perform plasma spheroidization treatment on the product to obtain spherical TiMn alloy powder;

[0012] S2. Graphene oxide coating: Add spherical TiMn alloy powder into the aqueous dispersion of graphene oxide, and dry it to obtain graphene oxide@spherical TiMn alloy powder;

[0013] S3. Preparation of copper nanowire deposited graphene oxide@spherical TiMn alloy powder: Add graphene oxide@spherical TiMn alloy powder and polyvinylpyrrolidone into ethylene glycol, add copper nitrate and ferric chloride, stir and mix evenly, heat and react, centrifuge, wash, and dry to obtain copper nanowire deposited graphene oxide@spherical TiMn alloy powder;

[0014] S4. Reduction: Carry out hydrazine hydrate vapor reduction on the copper nanowire deposited graphene oxide@spherical TiMn alloy powder to obtain copper nanowire deposited graphene@spherical TiMn alloy powder;

[0015] S5. Flame spraying: Spray the spherical TiMn alloy powder onto the surface of the titanium plate through flame spraying, and perform rapid cooling treatment with liquid nitrogen on the spraying part;

[0016] S6. Manganese infiltration: Place the anodic plate after flame spraying in a gradient manganese infiltration furnace for gradient manganese infiltration, and perform sandblasting and oxalic acid surface hydrogenation treatment to obtain a primary titanium alloy anodic plate;

[0017] S7. Surface spraying: Add the copper nanowire deposited graphene@spherical TiMn alloy powder into an organic solvent, disperse it evenly, and then evenly spray it onto the surface of the primary titanium alloy anodic plate, and dry it to obtain a titanium alloy anodic plate.

[0018] As a further improvement of the present invention, in step S1, the mass ratio of the Ti powder to the Mn powder is 1:2 - 4, the particle sizes of the Ti powder and the Mn powder are 40 - 55 μm, the conditions for ball milling are: ball milling at a speed of 150 - 300 r / min for 0.5 - 1 h, ball milling at a rotation speed of 500 r / min for 15 - 30 h, then reverse rotation, and ball milling at a rotation speed of 500 r / min for 15 - 30 h. The conditions for plasma spheroidization treatment are: powder feeding rate of 10 - 20 g / s, the particle size of the obtained spherical TiMn alloy powder is 5 - 15 μm, the sphericity > 99%, and the spheroidization rate > 98%. After plasma spheroidization, the oxygen content in the Ti powder can be further reduced.

[0019] As a further improvement of the present invention, in step S2, the concentration of the aqueous dispersion of graphene oxide is 0.5 - 1.5 mg / mL, the solid-liquid ratio of the spherical TiMn alloy powder to the aqueous dispersion of graphene oxide is 1:10 - 20 g / mL, and the drying is carried out under normal pressure or reduced pressure.

[0020] As a further improvement of the present invention, in step S3, the mass ratio of the graphene oxide@spherical TiMn alloy powder, polyvinylpyrrolidone, copper nitrate and ferric chloride is 10:4-6:6-8:0.1-0.15, the temperature of the heating reaction is 120-140 °C, and the time is 4-6 h.

[0021] As a further improvement of the present invention, in step S4, the time for hydrazine hydrate vapor reduction is 10-12 h.

[0022] As a further improvement of the present invention, the flame spraying conditions in step S5 are as follows: the oxygen flow rate is 1600-1900 SCFH, the argon flow rate is 6-10 L / min, the fuel oil flow rate is 4-6 GPH, the intermittent spraying method is adopted, the spraying distance is 300-500 mm, and the coating thickness is 100-300 μm. The method of rapid cooling with liquid nitrogen is to spray liquid nitrogen at the spraying part for cooling, and the spraying amount is 3-5 mL / cm 2 The surface of the titanium plate has been subjected to low-temperature degreasing and dehydrogenation treatment, and the conditions are as follows: under a vacuum pressure of 10 -4 -10 -2 Pa, first keep warm at 100-120 °C for 0.5-1 h, then keep warm at 350-550 °C for 2-4 h, and then keep warm at 550-600 °C for 1-2 h. The spraying part is subjected to rapid cooling treatment to quickly cool the alloy powder, playing a role in grain refinement.

[0023] As a further improvement of the present invention, the conditions for gradient manganese infiltration in step S6 are as follows: inert gas is filled until the pressure is 1 Pa-25 kPa, the heating rate is 3-8 °C / min, the low-temperature is 650 °C-750 °C, the heat preservation time is 1-3 h, the medium-temperature is 700-800 °C, the heat preservation time is 2-4 h, the high-temperature is 800-900 °C, and the heat preservation time is 1-3 h. By controlling the gradient temperature, the uniformity of manganese infiltration is controlled. Moreover, the manganese in the titanium-manganese alloy layer on the surface of the anode plate after flame spraying is not easy to volatilize and diffuse, improving the uniformity of manganese infiltration and enhancing the electrical conductivity and mechanical properties of the anode plate.

[0024] As a further improvement of the present invention, the organic solvent in step S7 is selected from at least one of ethyl acetate, acetone, butyl acetate, ethanol, and propanol, and the solid-liquid ratio of the copper nanowire-deposited graphene@spherical TiMn alloy powder and the organic solvent is 1:5-10 g / mL.

[0025] The present invention further protects a titanium alloy anode plate prepared by the above preparation method.

[0026] The present invention has the following beneficial effects:

[0027] In the traditional sintering furnace vacuum manganese infiltration process, pure Mn powder is coated on the Ti substrate, and then the entire Ti substrate is hoisted into the sintering furnace for manganese infiltration. Due to factors such as the size of the sintering furnace and the uniformity of the temperature field, it is difficult to prepare a Ti-based Ti-Mn coating anode with large size, uniform infiltration layer thickness, microstructure, and manganese content. The flame spraying technology and multi-layer conductive layer structure proposed in the present invention for preparing titanium alloy anode plates have the following innovative points compared with the traditional preparation technology:

[0028] The flame spraying technology of the present invention can meet the requirements of coating the surface of Ti plates of any size, while the size of the anode plates produced by the traditional vacuum furnace manganese infiltration technology is limited by the inner cavity size of the sintering furnace. By using the flame spraying technology for the preparation of the first coating on the surface of titanium alloy anode plates, precise control of the coating thickness can be achieved by adjusting the spraying time, speed, temperature, and powder feeding amount. In the traditional vacuum furnace high-temperature manganese infiltration process, due to the influence of the furnace temperature uniformity, the volatilization amount of manganese at different positions of the Ti plate is different during high-temperature manganese infiltration, resulting in non-uniform infiltration layer thickness.

[0029] The present invention uses plasma spheroidization technology to further increase the sphericity and spheroidization rate of TiMn alloy powder and reduce the oxygen content in the Ti layer. The increase in sphericity and spheroidization rate can ensure the fluidity and uniformity of powder feeding during flame spraying, and at the same time, the low oxygen content can increase the bonding property of the sprayed coating;

[0030] By using the flame spraying technology and combining high-energy ball milling to prepare pre-alloyed powder, the self-control of the alloy microstructure of the Ti-Mn coating can be achieved by adjusting the spraying parameters. By adjusting the spraying parameters to ensure the consistency of spraying everywhere, the fluctuation of the manganese content in the coating can be strictly controlled, which is beneficial to improving the product quality.

[0031] By using the flame spraying technology and the method of substrate undercooling treatment, the overall long-term heating of the Ti substrate can be avoided, thereby reducing the tendency of grain coarsening of the Ti substrate, which is beneficial to improving the overall mechanical properties of the titanium alloy anode plate. At the same time, the substrate after liquid nitrogen rapid undercooling treatment can refine the grains of the sprayed TiMn alloy, making the coating densified.

[0032] The TiMn alloy powder prepared by mechanical alloying in the present invention has a lower melting point than pure Mn powder, and can be flame sprayed at a lower temperature, weakening the tendency of grain coarsening of the titanium matrix, which is beneficial to improving the overall mechanical properties of the titanium alloy anode plate.

[0033] When traditional vacuum manganese infiltration is adopted, due to the characteristic that manganese elements are prone to evaporation, a large amount of manganese powder evaporates from the surface layer of the Ti substrate. This makes it difficult for the manganese content in the infiltration layer obtained by this technology to exceed 20 wt%. The present invention uses mechanical alloying technology to prepare Ti-Mn alloy powder with a high Mn content in advance and then spray it, so as to obtain a coating with a high surface manganese content and break through the limitations of traditional technology.

[0034] The present invention adopts a multi-layer structure. The first layer is that TiMn alloy powder is flame-sprayed on a titanium plate and undergoes gradient manganese infiltration to obtain gradient layers with different manganese contents, which can significantly change the electronic structure and conductivity of the Ti alloy. The introduction of Mn can reduce the band gap of the oxide film on the surface of the Ti alloy, thereby gradually improving the conductivity of the anode plate. The gradient structure can reduce the interface resistance and provide higher conductivity in the high-Mn content area, while maintaining good mechanical properties in the low-Mn content area, effectively improving the conductivity and service life of the anode plate; the second layer is a layer of copper nanowire-deposited graphene@spherical TiMn alloy powder. The copper nanowires are deposited on the surface and have a nanostructure, with extremely excellent conductivity. And due to the nanostructure, the surface structure of the anode plate is improved. The nanostructure increases the specific surface area and exposes more active sites, thereby improving the conductivity and reaction rate. Depositing copper nanowires on graphene, each carbon atom in graphene provides a π electron, and these electrons can move freely in the lattice of graphene to form a long-range conjugated network, endowing graphene with extremely high theoretical electron mobility, so its conductivity is extremely good. Moreover, before the reduction of graphene oxide, oxygen-containing groups are combined with copper nanoparticles through chemical bonds to form a stable composite structure, which not only enhances the dispersion of copper nanowires but also effectively prevents their oxidation, thus avoiding the influence of oxidation on the conductivity of the surface layer.

[0035] The product prepared by the present invention is used for the production of electrolytic manganese dioxide and has anti-passivation performance. At a current density of 100 A / m 2 Under normal industrial electrolysis conditions, the cell voltage can be stably within 2.3 - 2.4 volts. The product adheres well to the anode and there is no cracking or detachment phenomenon, overcoming the defects of existing industrial anodes and being an ideal anode for electrolytic manganese dioxide. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0037] Figure 1 SEM diagram of the primary titanium alloy anode plate prepared in Example 3;

[0038] Figure 2 SEM image of the primary titanium alloy anode plate prepared in Comparative Example 1. Specific embodiments

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] The particle sizes of Ti powder and Mn powder are 40 - 55 μm. The particle size D of graphene oxide 50 is 10 - 20 μm. The titanium plate is TA1 titanium plate, with Ti content of 99.5%, Fe content of 0.25%, oxygen content of 0.18%, carbon content of 0.04%, and nitrogen content of 0.03%.

[0041] Example 1

[0042] This example provides a method for preparing a titanium alloy anode plate, including the following steps:

[0043] S1. Plasma spheroidization treatment: Mix 1 g of Ti powder and 2 g of Mn powder, select ZrO 2 ceramic balls as grinding balls according to a ball-to-material ratio of 11:1 (mass ratio). The grinding balls include 10 - mm grinding balls and 3 - mm grinding balls, and the proportion of 10 - mm grinding balls: 3 - mm grinding balls = 6:4. At the same time, displace the air and fill with nitrogen for protection to prevent oxidation of Ti powder. Conduct ball milling. Ball mill at a speed of 150 r / min for 0.5 h, ball mill at a speed of 500 r / min for 15 h, then reverse and ball mill at a speed of 500 r / min for 15 h. Load the product into a plasma spheroidization powder feeding device with a powder feeding rate of 10 g / s to obtain spherical TiMn alloy powder with a particle size of 5 - 15 μm, a sphericity > 99%, and a spheroidization rate > 98% to obtain spherical TiMn alloy powder;

[0044] S2. Graphene oxide coating: Add 1 g of spherical TiMn alloy powder to 10 mL of 1.5 mg / mL graphene oxide aqueous dispersion, and dry at normal pressure to obtain graphene oxide@spherical TiMn alloy powder;

[0045] S3. Preparation of copper nanowire-deposited graphene oxide@spherical TiMn alloy powder: Add 10 g of graphene oxide@spherical TiMn alloy powder and 4 g of polyvinylpyrrolidone into 500 mL of ethylene glycol, add 6 g of copper nitrate and 0.1 g of ferric chloride, stir and mix for 15 min, heat to 120 °C, stir and react for 4 h, centrifuge, wash, and dry to obtain copper nanowire-deposited graphene oxide@spherical TiMn alloy powder;

[0046] S4. Reduction: Carry out hydrazine hydrate vapor reduction on the copper nanowire-deposited graphene oxide@spherical TiMn alloy powder for 10 h to obtain copper nanowire-deposited graphene@spherical TiMn alloy powder;

[0047] S5. Flame spraying: Spray the spherical TiMn alloy powder onto the surface of the titanium plate through a supersonic flame spraying device. The flame spraying conditions are as follows: the oxygen flow rate is 1600 SCFH, the argon flow rate is 6 L / min, the fuel flow rate is 4 GPH. The intermittent spraying method is adopted, the spraying distance is 300 mm, the coating thickness is 150 μm, and liquid nitrogen is sprayed at the spraying part for cooling, and the spraying amount is 3 mL / cm 2 ;

[0048] S6. Manganese infiltration: Place the anodic plate after flame spraying in a gradient manganese infiltration furnace for gradient manganese infiltration. Fill in an inert gas until the pressure is 10 kPa, the heating rate is 3 °C / min, the low temperature is 650 °C, the holding time is 1 h, the medium temperature is 700 °C, the holding time is 2 h, the high temperature is 800 °C, the holding time is 1 h, and then carry out sandblasting and oxalic acid surface hydrogenation treatment. The hydrogenation treatment time is 30 min to obtain a primary titanium alloy anodic plate;

[0049] S7. Surface spraying: Add 10 g of copper nanowire-deposited graphene@spherical TiMn alloy powder into 50 mL of ethyl acetate, disperse it by ultrasonic wave at 1000 W for 15 min, and evenly spray it on the surface of the primary titanium alloy anodic plate, and dry to obtain a titanium alloy anodic plate.

[0050] Example 2

[0051] This example provides a preparation method of a titanium alloy anodic plate, including the following steps:

[0052] S1. Plasma spheroidization treatment: Mix 1 g of Ti powder and 4 g of Mn powder, and select ZrO according to the ball-to-material ratio of 20:1 (mass ratio) 2Ceramic balls are used as grinding balls. The grinding balls include 10-mm grinding balls and 3-mm grinding balls, and the proportion is 10-mm grinding balls: 3-mm grinding balls = 8:2. At the same time, air is displaced and nitrogen is filled for protection to prevent the oxidation of Ti powder. Ball milling is carried out at a rotational speed of 300 r / min for 1 h, and then at a rotational speed of 500 r / min for 30 h. Subsequently, it is reversed and ball milled at a rotational speed of 500 r / min for 30 h. The product is loaded into a plasma spheroidization powder feeding device, and the powder feeding rate is 20 g / s. The obtained spherical TiMn alloy powder has a particle size of 5 - 15 μm, a sphericity > 99%, and a spheroidization rate > 98%, thus obtaining spherical TiMn alloy powder;

[0053] S2. Graphene oxide coating: 1 g of spherical TiMn alloy powder is added to 20 mL of a 0.5 mg / mL graphene oxide aqueous dispersion, and dried at normal pressure or reduced pressure to obtain graphene oxide@spherical TiMn alloy powder;

[0054] S3. Preparation of copper nanowire-deposited graphene oxide@spherical TiMn alloy powder: 10 g of graphene oxide@spherical TiMn alloy powder and 6 g of polyvinylpyrrolidone are added to 500 mL of ethylene glycol, 8 g of copper nitrate and 0.15 g of ferric chloride are added, stirred and mixed for 15 min, heated to 140 °C, stirred and reacted for 6 h, centrifuged, washed, and dried to obtain copper nanowire-deposited graphene oxide@spherical TiMn alloy powder;

[0055] S4. Reduction: The copper nanowire-deposited graphene oxide@spherical TiMn alloy powder is reduced by hydrazine hydrate vapor for 12 h to obtain copper nanowire-deposited graphene@spherical TiMn alloy powder;

[0056] S5. Flame spraying: The spherical TiMn alloy powder is sprayed onto the surface of a titanium plate through a supersonic flame spraying device. The flame spraying conditions are as follows: the oxygen flow rate is 1900 SCFH, the argon flow rate is 10 L / min, the fuel oil flow rate is 6 GPH. The intermittent spraying method is adopted, the spraying distance is 500 mm, and the coating thickness is 150 μm. Liquid nitrogen is sprayed at the spraying part for cooling, and the spraying amount is 5 mL / cm 2 ;

[0057] S6. Manganese infiltration: The anodic plate obtained by flame spraying is placed in a gradient manganese infiltration furnace for gradient manganese infiltration. An inert gas is filled to a pressure of 25 kPa, the heating rate is 8 °C / min, the low-temperature is 750 °C, the holding time is 3 h, the medium-temperature is 800 °C, the holding time is 4 h, the high-temperature is 900 °C, the holding time is 3 h, and then it is subjected to sandblasting and oxalic acid surface hydrogenation treatment. The hydrogenation treatment time is 50 min to obtain a primary titanium alloy anodic plate;

[0058] S7. Surface spraying: Add 10 g of copper nanowire-deposited graphene@spherical TiMn alloy powder into 100 mL of acetone, disperse it by ultrasonic wave at 1000 W for 15 min, spray it evenly on the surface of the primary titanium alloy anode plate, and dry it to obtain the titanium alloy anode plate.

[0059] Example 3

[0060] This example provides a method for preparing a titanium alloy anode plate, which includes the following steps:

[0061] S1. Plasma spheroidization treatment: Mix 1 g of Ti powder and 3 g of Mn powder, select ZrO 2 ceramic balls as grinding balls according to a ball-to-material ratio of 16:1 (mass ratio). The grinding balls include 10-mm grinding balls and 3-mm grinding balls, and the proportion of 10-mm grinding balls: 3-mm grinding balls = 7:3. At the same time, displace the air and fill it with nitrogen for protection to prevent the oxidation of Ti powder, and carry out ball milling. Ball mill at a speed of 200 r / min for 1 h, ball mill at a speed of 500 r / min for 20 h, then reverse and ball mill at a speed of 500 r / min for 20 h. Load the product into a plasma spheroidization powder feeding device, with a powder feeding rate of 15 g / s, to obtain spherical TiMn alloy powder with a particle size of 5 - 15 μm, a sphericity > 99%, and a spheroidization rate > 98% to obtain spherical TiMn alloy powder;

[0062] S2. Graphene oxide coating: Add 1 g of spherical TiMn alloy powder into 15 mL of 1 mg / mL graphene oxide aqueous dispersion, and dry it under normal pressure or reduced pressure to obtain graphene oxide@spherical TiMn alloy powder;

[0063] S3. Preparation of copper nanowire-deposited graphene@spherical TiMn alloy powder: Add 10 g of graphene oxide@spherical TiMn alloy powder and 5 g of polyvinylpyrrolidone into 500 mL of ethylene glycol, add 7 g of copper nitrate and 0.12 g of ferric chloride, stir and mix for 15 min, heat to 130 °C, stir and react for 5 h, centrifuge, wash, and dry to obtain copper nanowire-deposited graphene@spherical TiMn alloy powder;

[0064] S4. Reduction: Carry out hydrazine hydrate vapor reduction on the copper nanowire-deposited graphene@spherical TiMn alloy powder for 11 h to obtain copper nanowire-deposited graphene@spherical TiMn alloy powder;

[0065] S5. Flame spraying: Spray the spherical TiMn alloy powder onto the surface of the titanium plate through a supersonic flame spraying device. The flame spraying conditions are as follows: the oxygen flow rate is 1750 SCFH, the argon flow rate is 8 L / min, the fuel flow rate is 5 GPH. Adopt an intermittent spraying method, the spraying distance is 400 mm, the coating thickness is 150 μm, and liquid nitrogen is sprayed at the spraying part for cooling, and the spraying amount is 4 mL / cm2 ;

[0066] S6. Manganese infiltration: Place the anodic plate with flame spraying in a gradient manganese infiltration furnace for gradient manganese infiltration. Fill with inert gas until the pressure reaches 15 kPa, with a heating rate of 5 °C / min. The low-temperature is 700 °C with a holding time of 2 h, the medium-temperature is 750 °C with a holding time of 3 h, and the high-temperature is 850 °C with a holding time of 2 h. Then, perform sandblasting and oxalic acid surface hydrogenation treatment for 40 min to obtain the primary titanium alloy anodic plate. Conduct microscopic morphology analysis on the obtained primary titanium alloy anodic plate, and its SEM image is as shown in Figure 1 , and it can be seen from Figure 1 that the surface coating is dense, and the coating thickness is about 150 μm. After testing, the surface Mn content is 39%.

[0067] S7. Surface spraying: Add 10 g of copper nanowire-deposited graphene@spherical TiMn alloy powder into 70 mL of ethanol, disperse it by ultrasonic wave at 1000 W for 15 min, and spray it evenly on the surface of the primary titanium alloy anodic plate and dry it to obtain the titanium alloy anodic plate.

[0068] Comparative Example 1

[0069] Compared with Example 3, the difference lies in that no plasma spheroidization treatment is carried out in step S1.

[0070] Specifically as follows:

[0071] (1) Ball milling treatment: Mix 1 g of Ti powder and 3 g of Mn powder, select ZrO 2 ceramic balls as grinding balls according to a ball-to-material ratio of 16:1 (mass ratio). The grinding balls include 10-mm grinding balls and 3-mm grinding balls, and the proportion of 10-mm grinding balls: 3-mm grinding balls = 7:3. At the same time, displace the air and fill with nitrogen for protection to prevent oxidation of Ti powder, and perform ball milling. Ball mill at a speed of 200 r / min for 1 h, ball mill at a speed of 500 r / min for 20 h, and then reverse and ball mill at a speed of 500 r / min for 20 h to obtain TiMn alloy powder.

[0072] Conduct microscopic morphology analysis on the primary titanium alloy anodic plate prepared in step S6, and its SEM image is as shown in Figure 2 , and it can be seen from Figure 2 that the coating is not smooth and uniform, with many defects. After testing, the surface Mn content is 16.2%.

[0073] Comparative Example 2

[0074] Compared with Example 3, the difference lies in that steps S2 and S4 are not carried out.

[0075] Specifically as follows:

[0076] (1) Plasma spheroidization treatment: Mix 1 g of Ti powder and 3 g of Mn powder, select ZrO ceramic balls as grinding balls according to a ball-to-material ratio of 16:1 (mass ratio). The grinding balls include 10 mm grinding balls and 3 mm grinding balls, and the proportion of 10 mm grinding balls: 3 mm grinding balls = 7:3. At the same time, displace the air and fill it with nitrogen for protection to prevent the oxidation of Ti powder. Then carry out ball milling. Ball mill at a speed of 200 r / min for 1 h, ball mill at a speed of 500 r / min for 20 h, then reverse and ball mill at a speed of 500 r / min for 20 h. Load the product into the plasma spheroidization powder feeding device, with a powder feeding rate of 15 g / s. The particle size of the spherical TiMn alloy powder obtained is 5 - 15 μm, the sphericity > 99%, and the spheroidization rate > 98% to obtain spherical TiMn alloy powder; 2 (2) Preparation of copper nanowire @ spherical TiMn alloy powder: Add 10 g of spherical TiMn alloy powder and 5 g of polyvinylpyrrolidone to 500 mL of ethylene glycol, add 7 g of copper nitrate and 0.12 g of ferric chloride, stir and mix for 15 min, heat to 130 °C, stir and react for 5 h, centrifuge, wash, and dry to obtain copper nanowire @ spherical TiMn alloy powder;

[0077] (3) Flame spraying: Spray the spherical TiMn alloy powder onto the surface of the titanium plate through a supersonic flame spraying device. The flame spraying conditions are as follows: the oxygen flow rate is 1750 SCFH, the argon flow rate is 8 L / min, the fuel oil flow rate is 5 GPH. Adopt an intermittent spraying method, the spraying distance is 400 mm, the coating thickness is 150 μm, and liquid nitrogen is sprayed at the spraying part for cooling, and the spraying amount is 4 mL / cm;

[0078] (4) Manganese infiltration: Place the anodic plate after flame spraying in a gradient manganese infiltration furnace for gradient manganese infiltration. Fill with an inert gas to a pressure of 15 kPa, with a heating rate of 5 °C / min. The low-temperature is 700 °C, the holding time is 2 h, the medium-temperature is 750 °C, the holding time is 3 h, the high-temperature is 850 °C, the holding time is 2 h, and then carry out sandblasting and oxalic acid surface hydrogenation treatment. The hydrogenation treatment time is 40 min to obtain a primary titanium alloy anodic plate. 2 ;

[0079] (5) Surface spraying: Add 10 g of copper nanowire @ spherical TiMn alloy powder to 70 mL of ethanol, disperse it by ultrasonic wave at 1000 W for 15 min, and uniformly spray it on the surface of the primary titanium alloy anodic plate, then dry to obtain a titanium alloy anodic plate.

[0080] Comparative Example 3

[0081] Different from Example 3, the difference is that step S3 is not carried out.

[0082] Specifically as follows:

[0083] ​

[0084] (1) Plasma spheroidization treatment: Mix 1 g of Ti powder and 3 g of Mn powder, select ZrO 2 ceramic balls as grinding balls according to a ball-to-material ratio of 16:1 (mass ratio). The grinding balls include 10 mm grinding balls and 3 mm grinding balls, and the proportion of 10 mm grinding balls: 3 mm grinding balls = 7:3. At the same time, displace the air and fill it with nitrogen for protection to prevent the oxidation of Ti powder. Then carry out ball milling. Ball mill at a speed of 200 r / min for 1 h, ball mill at a speed of 500 r / min for 20 h, then reverse and ball mill at a speed of 500 r / min for 20 h. Load the product into the plasma spheroidization powder feeding device with a powder feeding rate of 15 g / s. The particle size of the spherical TiMn alloy powder obtained is 5 - 15 μm, the sphericity > 99%, and the spheroidization rate > 98% to obtain spherical TiMn alloy powder;

[0085] (2) Graphene oxide coating: Add 1 g of spherical TiMn alloy powder to 15 mL of 1 mg / mL graphene oxide aqueous dispersion, and dry it under normal pressure or reduced pressure to obtain graphene oxide @ spherical TiMn alloy powder;

[0086] (3) Reduction: Carry out hydrazine hydrate vapor reduction on the graphene oxide @ spherical TiMn alloy powder for 11 h to obtain graphene @ spherical TiMn alloy powder;

[0087] (4) Flame spraying: Spray the spherical TiMn alloy powder onto the surface of the titanium plate through a supersonic flame spraying device. The flame spraying conditions are as follows: the oxygen flow rate is 1750 SCFH, the argon flow rate is 8 L / min, the fuel flow rate is 5 GPH. Adopt an intermittent spraying method, the spraying distance is 400 mm, the coating thickness is 150 μm, and liquid nitrogen is sprayed at the spraying part for cooling, and the spraying amount is 4 mL / cm 2 ;

[0088] (5) Manganese infiltration: Place the anodic plate after flame spraying in a gradient manganese infiltration furnace for gradient manganese infiltration. Fill it with inert gas until the pressure is 15 kPa, the heating rate is 5 °C / min, the low temperature is 700 °C, the holding time is 2 h, the medium temperature is 750 °C, the holding time is 3 h, the high temperature is 850 °C, and the holding time is 2 h. Then carry out sandblasting and oxalic acid surface hydrogenation treatment, and the hydrogenation treatment time is 40 min to obtain a primary titanium alloy anodic plate.

[0089] (6) Surface spraying: Add 10 g of graphene @ spherical TiMn alloy powder to 70 mL of ethanol, disperse it ultrasonically at 1000 W for 15 min, and spray it evenly on the surface of the primary titanium alloy anodic plate and dry it to obtain a titanium alloy anodic plate.

[0090] Comparative Example 4

[0091] Compared with Example 3, the difference lies in that steps S5 and S6 are not carried out.

[0092] Specifically as follows:

[0093] (1) Plasma spheroidization treatment: Mix 1 g of Ti powder and 3 g of Mn powder, select ZrO ceramic balls as grinding balls according to a ball-to-material ratio of 16:1 (mass ratio). The grinding balls include 10-mm grinding balls and 3-mm grinding balls, and the proportion of 10-mm grinding balls to 3-mm grinding balls is 7:3. At the same time, displace the air and fill it with nitrogen for protection to prevent the oxidation of Ti powder. Then carry out ball milling. Ball mill at a speed of 200 r / min for 1 h, ball mill at a speed of 500 r / min for 20 h, then reverse and ball mill at a speed of 500 r / min for 20 h. Load the product into the plasma spheroidization powder feeding device with a powder feeding rate of 15 g / s. The particle size of the spherical TiMn alloy powder obtained is 5 - 15 μm, the sphericity > 99%, and the spheroidization rate > 98% to obtain spherical TiMn alloy powder; 2

[0094] (2) Graphene oxide coating: Add 1 g of spherical TiMn alloy powder to 15 mL of 1 mg / mL graphene oxide aqueous dispersion, and dry it under normal pressure or reduced pressure to obtain graphene oxide@spherical TiMn alloy powder;

[0095] (3) Preparation of copper nanowire-deposited graphene oxide@spherical TiMn alloy powder: Add 10 g of graphene oxide@spherical TiMn alloy powder and 5 g of polyvinylpyrrolidone to 500 mL of ethylene glycol, add 7 g of copper nitrate and 0.12 g of ferric chloride, stir and mix for 15 min, heat to 130 °C, stir and react for 5 h, centrifuge, wash, and dry to obtain copper nanowire-deposited graphene oxide@spherical TiMn alloy powder;

[0096] (4) Reduction: Carry out hydrazine hydrate vapor reduction on the copper nanowire-deposited graphene oxide@spherical TiMn alloy powder for 11 h to obtain copper nanowire-deposited graphene@spherical TiMn alloy powder;

[0097] (5) Surface spraying: Pre-treat the titanium plate by sandblasting and surface hydrogenation with oxalic acid for 40 min to obtain a pre-treated titanium plate. Add 10 g of copper nanowire-deposited graphene@spherical TiMn alloy powder to 70 mL of ethanol, ultrasonically disperse it at 1000 W for 15 min, and evenly spray it on the surface of the pre-treated titanium plate, then dry it to obtain a titanium alloy anode plate.

[0098] Comparative Example 5

[0099] Compared with Example 3, the difference lies in that step S7 is not carried out.

[0100] Specifically as follows:

[0101] (1) Plasma spheroidization treatment: Mix 1 g of Ti powder and 3 g of Mn powder, select ZrO ceramic balls as grinding balls according to a ball-to-material ratio of 16:1 (mass ratio). The grinding balls include 10 mm grinding balls and 3 mm grinding balls, and the proportion of 10 mm grinding balls to 3 mm grinding balls is 7:3. At the same time, displace the air and fill with nitrogen for protection to prevent oxidation of Ti powder. Then carry out ball milling. Ball mill at a speed of 200 r / min for 1 h, ball mill at a speed of 500 r / min for 20 h, then reverse and ball mill at a speed of 500 r / min for 20 h. Load the product into the plasma spheroidization powder feeding device with a powder feeding rate of 15 g / s. The obtained spherical TiMn alloy powder has a particle size of 5 - 15 μm, a sphericity > 99%, and a balling rate > 98% to obtain spherical TiMn alloy powder; 2 (2) Flame spraying: Spray the spherical TiMn alloy powder onto the surface of the titanium plate through a supersonic flame spraying device. The flame spraying conditions are as follows: oxygen flow rate is 1750 SCFH, argon flow rate is 8 L / min, fuel oil flow rate is 5 GPH. Adopt an intermittent spraying method, spraying distance is 400 mm, coating thickness is 150 μm. Spray liquid nitrogen at the spraying part for cooling, and the spraying amount is 4 mL / cm;

[0102] (3) Manganese infiltration: Place the anodic plate after flame spraying in a gradient manganese infiltration furnace for gradient manganese infiltration. Fill with inert gas until the pressure is 15 kPa, heating rate is 5 °C / min, low temperature is 700 °C, holding time is 2 h, medium temperature is 750 °C, holding time is 3 h, high temperature is 850 °C, holding time is 2 h. Then carry out sandblasting and oxalic acid surface hydrogenation treatment, and the hydrogenation treatment time is 40 min to obtain a titanium alloy anodic plate. 2 ;

[0103] Test Example 1

[0104] Conduct mechanical property tests on the titanium alloy anodic plates prepared in Examples 1 - 3 and Comparative Examples 1 - 5. The results are shown in Table 1.

[0105] Table 1

[0106] As can be seen from the above table, the titanium alloy anodic plates prepared in Examples 1 - 3 of the present invention have good mechanical properties.

[0107]

[0108] Test Example 2

[0109] Conduct performance tests on the titanium alloy anodic plates prepared in Examples 1 - 3 and Comparative Examples 1 - 5 under normal industrial electrolysis conditions at a current density of 100 A / m². The results are shown in Table 2.

[0110] Table 2 2 As can be seen from the above table, the titanium alloy anodic plates prepared in Examples 1 - 3 of the present invention have good mechanical properties.

[0111] Table 2

[0112]

[0113] As can be seen from the above table, the titanium alloy anode plates prepared in Examples 1-3 of the present invention have a stable cell voltage within 2.3-2.4 V at a current density of 100 A / m 2 and a relatively high MnO 2 electrolysis efficiency.

[0114] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a titanium alloy anode plate, characterized in that: The following steps are involved: S1. Plasma spheroidization: Ti powder and Mn powder are mixed, ball-milled under inert gas protection, and the product is subjected to plasma spheroidization to obtain spherical TiMn alloy powder; S2. Graphene oxide coating: Spherical TiMn alloy powder was added to an aqueous dispersion of graphene oxide and dried to obtain graphene oxide @ spherical TiMn alloy powder; S3. Preparation of copper nanowire-deposited graphene oxide @ spherical TiMn alloy powder: adding graphene oxide @ spherical TiMn alloy powder and polyvinyl pyrrolidone to ethylene glycol, adding copper nitrate and ferric chloride, stirring and mixing, heating for reaction, centrifuging, washing, and drying to obtain copper nanowire-deposited graphene oxide @ spherical TiMn alloy powder; S4. Reduction: reducing the copper nanowire-deposited graphene oxide @ spherical TiMn alloy powder with hydrazine hydrate vapor to obtain copper nanowire-deposited graphene @ spherical TiMn alloy powder; S5. Flame spraying: spherical TiMn alloy powder is flame sprayed onto the surface of the titanium plate, and the sprayed part is subjected to liquid nitrogen rapid cooling treatment; the flame spraying conditions are: oxygen flow rate is 1600-1900SCFH, argon flow rate is 6-10L / min, fuel flow rate is 4-6GPH, intermittent spraying is adopted, spraying distance is 300-500mm, coating thickness is 100-300μm, and the liquid nitrogen rapid cooling method is to spray liquid nitrogen on the sprayed part to cool it down, and the spraying amount is 3-5mL / cm 2 The titanium plate surface is subjected to low temperature degreasing and dehydrogenation treatment under the following conditions: -4 -10 -2 Under the vacuum pressure of Pa, keep the temperature at 100-120℃ for 0.5-1h, then keep the temperature at 350-550℃ for 2-4h, and then keep the temperature at 550-600℃ for 1-2h; S6. Manganese infiltration: placing the flame-sprayed anode plate in a gradient manganese infiltration furnace for gradient manganese infiltration, and then subjecting the anode plate to sandblasting and oxalic acid surface hydrogenation treatment to obtain a primary titanium alloy anode plate; the gradient manganese infiltration conditions are: filling with inert gas to a pressure of 1Pa-25kPa, a heating rate of 3-8°C / min, a low temperature of 650°C-750°C, a holding time of 1-3h, a medium temperature of 700-800°C, a holding time of 2-4h, a high temperature of 800-900°C, and a holding time of 1-3h; S7. Surface spraying: adding copper nanowire-deposited graphene@spherical TiMn alloy powder into an organic solvent, dispersing it evenly, and then spraying it evenly on the surface of the primary titanium alloy anode plate, drying it, and obtaining a titanium alloy anode plate.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the Ti powder to the Mn powder in step S1 is 1:2-4, the particle size of the Ti powder and the Mn powder is 40-55 μm, the ball milling conditions are: ball milling at a speed of 150-300 r / min for 0.5-1 h, ball milling at a speed of 500 r / min for 15-30 h, then reversing, and ball milling at a speed of 500 r / min for 15-30 h, the conditions of the plasma spheroidization treatment are: powder feeding rate 10-20 g / s, and the particle size of the spherical TiMn alloy powder obtained is 5-15 μm, the sphericity is>99%, and the spheroidization rate is>98%.

3. The preparation method according to claim 1, characterized in that: The concentration of the graphene oxide aqueous dispersion in step S2 is 0.5-1.5 mg / mL, the solid-liquid ratio of the spherical TiMn alloy powder and the graphene oxide aqueous dispersion is 1:10-20 g / mL, and the drying is drying under normal pressure or reduced pressure.

4. The preparation method according to claim 1, characterized in that: In step S3, the mass ratio of graphene oxide @ spherical TiMn alloy powder, polyvinyl pyrrolidone, copper nitrate and ferric chloride is 10:4-6:6-8:0.1-0.15, the temperature of the heating reaction is 120-140° C., and the time is 4-6 hours.

5. The preparation method according to claim 1, characterized in that: The time for the hydrazine hydrate steam reduction in step S4 is 10-12 hours.

6. The preparation method according to claim 1, characterized in that: The organic solvent in step S7 is selected from at least one of ethyl acetate, acetone, butyl acetate, ethanol, and propanol, and the solid-liquid ratio of the copper nanowire deposited graphene @ spherical TiMn alloy powder and the organic solvent is 1:5-10 g / mL.

7. A titanium alloy anode plate obtained by the preparation method according to any one of claims 1 to 6.

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