Nickel powder with high stability, and preparation method and application thereof

Abstract

The application discloses a kind of nickel powder with high stability and its preparation method and application, it is related to metal material technical field.The preparation method includes the following steps: S1, water-soluble nickel salt solution is mixed with reducing agent and is reacted to obtain the dispersion liquid containing nickel powder, solid-liquid separation is carried out to obtain filter cake;S2, the filter cake is washed by antioxidant solution, and the mixture of the filter cake and surface treatment agent solution is prepared;The surface treatment agent in the surface treatment agent solution includes polyoxyethylene stearyl alcohol ether and oleylamine with mass ratio (0.5-2):1;The amount of the surface treatment agent is 1wt%-5wt% of the filter cake.Thereby, nickel powder with excellent long-term stability can be prepared.

Description

Technical Field

[0001] This invention relates to the field of metallic materials technology, and in particular to a nickel powder with high stability, its preparation method, and its application. Background Technology

[0002] Ultrafine nickel powder is widely used in conductive pastes, catalysis, and magnetic materials due to its excellent electrical conductivity, catalytic properties, and magnetic properties. However, ultrafine nickel powder has an extremely high specific surface area and surface energy, resulting in a strong tendency to agglomerate during production and storage. This agglomeration not only leads to poor powder flowability, making subsequent paste preparation and molding processes difficult, but also significantly reduces its electrical conductivity and catalytic properties in the final product. Furthermore, ultrafine nickel powder readily reacts with oxygen and moisture in the air, forming an insulating or weakly conductive passivation layer such as nickel oxide or nickel hydroxide on its surface, which further exacerbates the hard agglomeration between particles.

[0003] In existing technologies, the surface of nickel powder is usually modified during the preparation of ultrafine nickel powder to improve the dispersibility of nickel powder particles. However, this modification treatment often focuses on solving the problem of "instant dispersion" during the preparation process. The organic protective layer formed may fail during long-term storage due to volatilization, degradation or molecular chain reconstruction, and cannot provide long-term stable protection.

[0004] Developing a method for preparing nickel powder that maintains good dispersibility and reduces agglomeration during long-term storage is an urgent problem to be solved. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a method for preparing nickel powder.

[0006] The present invention also provides nickel powder prepared by the above preparation method.

[0007] This invention also provides applications of nickel powder.

[0008] A method for preparing nickel powder according to a first aspect of the present invention includes the following steps: S1. A water-soluble nickel salt solution is mixed with a reducing agent to react and obtain a dispersion containing nickel powder. Solid-liquid separation is performed to obtain a filter cake. S2. After the filter cake is washed with an antioxidant solution, a mixture of the filter cake and a surface treatment agent solution is prepared. The surface treatment agent in the surface treatment agent solution comprises polyoxyethylene stearyl alcohol ether and oleylamine in a mass ratio of (0.5-2):1; The amount of the surface treatment agent is 1wt%-5wt% of the filter cake.

[0009] The preparation method according to embodiments of the present invention has at least the following beneficial effects: The preparation method of the embodiment can prepare nickel powder with good dispersibility, excellent long-term stability and good oxidation resistance. After long-term storage (such as more than one year), it can still maintain excellent dispersibility, effectively inhibit hard agglomeration and oxidation, and maintain good electrical, magnetic and catalytic properties.

[0010] According to some embodiments of the present invention, the water-soluble nickel salt includes at least one of nickel sulfate, nickel chloride, nickel nitrate, and nickel acetate.

[0011] According to some embodiments of the present invention, the concentration of the water-soluble nickel salt in the water-soluble nickel salt solution is 2wt%-10wt%. For example, it can be 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%.

[0012] According to some embodiments of the present invention, the solvent for the water-soluble nickel salt is an aqueous solution of diethylene glycol. This provides a suitable reaction environment, effectively controlling the reduction of nickel ions and the nucleation and growth rate of particles.

[0013] According to some embodiments of the present invention, the concentration of diethylene glycol in the aqueous diethylene glycol solution is 10wt%-30wt%. For example, it can be 10wt%, 10.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, 15wt%, 15.5wt%, 16wt%, 16.5wt%, 17wt%, 17.5wt%, 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt%, 20.5wt%, 21wt%, 21.5wt%, 22wt%, 22.5wt%, 23wt%, 23.5wt%, 24wt%, 24.5wt%, 25wt%, 25.5wt%, 26wt%, 26.5wt%, 27wt%, 27.5wt%, 28wt%, 28.5wt%, 29wt%, 29.5wt%, or 30wt%.

[0014] According to some embodiments of the present invention, the reducing agent includes at least one of sodium borohydride, potassium borohydride, and hydrazine hydrate.

[0015] According to some embodiments of the present invention, the molar ratio of the reducing agent to the water-soluble nickel salt is (1.5-5):1. For example, it can be 1.5:1, 1.7:1, 1.9:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1, 4:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1, or 5:1.

[0016] According to some embodiments of the present invention, the reaction pH of S1 is not lower than 8. For example, it can be 8, 8.2, 8.4, 8.6, 8.8, 9, 9.2, 9.4, 9.6, 9.8, 10, 10.2, 10.4, 10.6, 10.8, 11, 11.2, 11.4, 11.6, 11.8, 12, 12.2, 12.4, 12.6, 12.8, 13, 13.2, 13.4, 13.6, or 13.8.

[0017] According to some embodiments of the present invention, the reaction temperature of S1 is 65℃-80℃. For example, it can be 65℃, 66℃, 67℃, 68℃, 69℃, 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃.

[0018] According to some embodiments of the present invention, the reaction time of S1 is 1 h to 5 h. For example, it can be 1 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h, 2 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h, 4 h, 4.2 h, 4.4 h, 4.6 h, 4.8 h, or 5 h.

[0019] According to some embodiments of the present invention, the reactants of S1 also include a dispersant.

[0020] According to some embodiments of the present invention, the dispersant includes at least one selected from polyvinylpyrrolidone, polyethylene glycol, carboxymethyl cellulose, and hydroxypropyl cellulose.

[0021] According to some embodiments of the present invention, the mass ratio of the dispersant to the molar amount of the water-soluble nickel salt is (10-30):1. For example, it can be 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, 28:1, 29:1, or 30:1.

[0022] According to some embodiments of the present invention, the antioxidant includes ascorbic acid.

[0023] According to some embodiments of the present invention, the concentration of the antioxidant in the antioxidant solution is 0.1wt%-0.5wt%. For example, it can be 0.1wt%, 0.12wt%, 0.14wt%, 0.16wt%, 0.18wt%, 0.2wt%, 0.22wt%, 0.24wt%, 0.26wt%, 0.28wt%, 0.3wt%, 0.32wt%, 0.34wt%, 0.36wt%, 0.38wt%, 0.4wt%, 0.42wt%, 0.44wt%, 0.46wt%, 0.48wt%, or 0.5wt%.

[0024] According to some embodiments of the present invention, the antioxidant solution is pre-cooled at 0°C-10°C before use. For example, the temperature can be 0°C, 1°C, 2°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, or 10°C.

[0025] According to some embodiments of the present invention, the mass ratio of polyoxyethylene stearyl alcohol ether to oleylamine is (0.5-2):1. For example, it can be 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, or 2:1.

[0026] According to some embodiments of the present invention, the amount of the surface treatment agent is 1wt%-5wt% of the filter cake. For example, it can be 1wt%, 1.2wt%, 1.4wt%, 1.6wt%, 1.8wt%, 2wt%, 2.2wt%, 2.4wt%, 2.6wt%, 2.8wt%, 3wt%, 3.2wt%, 3.4wt%, 3.6wt%, 3.8wt%, 4wt%, 4.2wt%, 4.4wt%, 4.6wt%, 4.8wt%, or 5wt%.

[0027] According to some embodiments of the present invention, the mass-to-volume ratio of the filter cake to the surface treatment agent solution is 1 g:(8-12) mL. For example, it can be 1 g: 8 mL, 1 g: 8.2 mL, 1 g: 8.4 mL, 1 g: 8.6 mL, 1 g: 8.8 mL, 1 g: 9 mL, 1 g: 9.2 mL, 1 g: 9.4 mL, 1 g: 9.6 mL, 1 g: 9.8 mL, 1 g: 10 mL, 1 g: 10.2 mL, 1 g: 10.4 mL, 1 g: 10.6 mL, 1 g: 10.8 mL, 1 g: 11 mL, 1 g: 11.2 mL, 1 g: 11.4 mL, 1 g: 11.6 mL, 1 g: 11.8 mL, or 1 g: 12 mL.

[0028] According to some embodiments of the present invention, the preparation method further includes reacting the mixture at 35°C-60°C, followed by washing and drying. The reaction is carried out at a stirring speed of 70 rpm-80 rpm. For example, the reaction temperature is 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, or 60°C; the stirring speed can be 70 rpm, 71 rpm, 72 rpm, 73 rpm, 74 rpm, 75 rpm, 76 rpm, 77 rpm, 78 rpm, 79 rpm, or 80 rpm.

[0029] According to a second aspect of the present invention, a nickel powder is prepared by the preparation method described in the first aspect.

[0030] The application of nickel powder in conductive or catalytic materials as described in the second aspect embodiment of the present invention.

[0031] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0032] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0033] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0034] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0035] Unless otherwise specified, "not less than" in this invention means greater than or equal to, and should be understood as including the stated number.

[0036] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0037] Example 1 This example provides a method for preparing nickel powder, the steps of which are as follows: S1. Add NaOH to the nickel chloride solution until the pH reaches 10, then add 1.5 g of polyvinylpyrrolidone (PVP) and stir continuously until the PVP dissolves. Subsequently, slowly add 12 g of sodium borohydride to the solution, and incubate the reaction in a 75°C water bath for 2 hours. Filter to obtain a filter cake.

[0038] The preparation method of nickel chloride solution is as follows: 60 g of diethylene glycol and 300 g of deionized water are mixed and stirred at 300 rpm for 1 h on a magnetic stirrer to make them fully mixed and uniform, so as to obtain a diethylene glycol aqueous solution; 16 g of nickel chloride is added to the diethylene glycol aqueous solution and the stirring is continued until the nickel chloride is completely dissolved to obtain a nickel chloride solution.

[0039] S2. After washing the filter cake twice with a 0.2wt% ascorbic acid aqueous solution pre-cooled at 4℃, it was redispersed in the surface treatment agent solution at a mass-to-volume ratio of 1 g: 10 mL and stirred at 40℃ and 70 rpm for 1 h. Then, it was vacuum filtered to obtain crude nickel powder.

[0040] The surface treatment agent solution was prepared by dissolving 0.01 g of polyoxyethylene stearyl alcohol ether and 0.01 g of oleylamine in 10 mL of anhydrous ethanol.

[0041] S3. Wash the crude nickel powder once with anhydrous ethanol, dry it under vacuum at 80°C for 6 hours, and cool it naturally to room temperature to obtain nickel powder.

[0042] Example 2 This example provides a method for preparing nickel powder, the steps of which are as follows: S1. Add NaOH to the nickel chloride solution until the pH reaches 10, then add 2 g of PVP and stir continuously until the PVP dissolves. Subsequently, slowly add 10 g of sodium borohydride to the solution, and incubate the reaction in a 70°C water bath for 3 h. After filtration, obtain the filter cake.

[0043] The preparation method of nickel chloride solution is as follows: 80 g of diethylene glycol and 280 g of deionized water are mixed and stirred at 400 rpm for 1.5 h on a magnetic stirrer to make them fully mixed and homogeneous, so as to obtain a diethylene glycol aqueous solution; 18 g of nickel chloride is added to the diethylene glycol aqueous solution and stirred until the nickel chloride is completely dissolved to obtain a nickel chloride solution.

[0044] S2. After washing the filter cake twice with a 0.4wt% ascorbic acid aqueous solution pre-cooled at 4℃, it was redispersed in the surface treatment agent solution at a mass-to-volume ratio of 1 g: 10 mL and stirred at 50℃ and 80 rpm for 30 min. Then, it was vacuum filtered to obtain crude nickel powder.

[0045] The surface treatment agent solution was prepared by dissolving 0.015 g of polyoxyethylene stearyl alcohol ether and 0.01 g of oleylamine in 10 mL of anhydrous ethanol.

[0046] S3. Wash the crude nickel powder once with anhydrous ethanol, dry it under vacuum at 80°C for 6 hours, and cool it naturally to room temperature to obtain nickel powder.

[0047] Comparative Example 1 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that the 0.2wt% ascorbic acid aqueous solution in step S2 is replaced with an equal volume of anhydrous ethanol.

[0048] Comparative Example 2 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that the surface treatment agent solution in step S2 is replaced with an equal volume of anhydrous ethanol.

[0049] Comparative Example 3 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that the polyoxyethylene stearyl alcohol ether in step S2 is replaced with an equal mass of dehydrated sorbitan monostearate.

[0050] Comparative Example 4 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that oleylamine in step S2 is replaced with an equal mass of octadecyl alcohol.

[0051] Comparative Example 5 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that the content of oleylamine and polyoxyethylene stearyl alcohol ether in the surface treatment agent solution in step S2 is increased to 10 times the mass concentration.

[0052] Comparative Example 6 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that the concentration of polyoxyethylene stearyl alcohol ether in the surface treatment agent solution in step S2 is adjusted to 0.0005 g / mL and the concentration of oleylamine is adjusted to 0.0015 g / mL.

[0053] Comparative Example 7 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that the concentration of polyoxyethylene stearyl alcohol ether in the surface treatment agent solution in step S2 is adjusted to 0.0015 g / mL and the concentration of oleylamine is adjusted to 0.0005 g / mL.

[0054] Comparative Example 8 This example provides a method for preparing nickel powder, which is basically the same as that in Example 1, except that the diethylene glycol in step S1 is replaced with an equal mass of deionized water.

[0055] Detection example The ultrafine nickel powders prepared in Examples 1-2 and Comparative Examples 1-8 were placed at 50% humidity and 25°C for 0 days, 30 days, and 180 days, respectively. The particle size of the nickel powders was analyzed using a particle size analyzer to evaluate their stability. The specific test results are shown in Table 1.

[0056] Table 1

[0057] The preparation methods in Examples 1-2 can produce ultrafine nickel powder with small particle size, good dispersibility, and good long-term stability.

[0058] The embodiments of the present invention have been described in detail above with reference to the examples. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for producing a nickel powder, characterized by, Includes the following steps: S1. A water-soluble nickel salt solution is mixed with a reducing agent to react and obtain a dispersion containing nickel powder. Solid-liquid separation is performed to obtain a filter cake. S2, the filter cake after washing with antioxidant solution, the mixture of the filter cake and surface treatment agent solution is prepared; the mixture is heated at 35°C 60°C, washed, dried; the reaction is carried out at a stirring speed of 70 rpm-80 rpm; The surface treatment agent in the surface treatment agent solution comprises polyoxyethylene stearyl alcohol ether and oleylamine in a mass ratio of (0.5-2):1; The amount of the surface treatment agent is 1wt%-5wt% of the filter cake.

2. The preparation method according to claim 1, characterized in that, The solvent for the water-soluble nickel salt is an aqueous solution of diethylene glycol.

3. The preparation method according to claim 2, characterized in that, The concentration of diethylene glycol in the aqueous diethylene glycol solution is 10wt%-30wt%.

4. The preparation method according to claim 1, characterized in that, The reactants in S1 also include a dispersant.

5. The preparation method according to claim 4, characterized in that, The dispersant includes at least one of polyvinylpyrrolidone, polyethylene glycol, carboxymethyl cellulose, and hydroxypropyl cellulose.

6. The preparation method according to claim 4, characterized in that, The ratio of the mass of the dispersant to the molar amount of the water-soluble nickel salt is (10-30):

1.

7. The preparation method according to claim 1, characterized in that, The antioxidant includes ascorbic acid; and / or, the concentration of the antioxidant in the antioxidant solution is 0.1wt%-0.5wt%.

8. The preparation method according to claim 1, characterized in that, The mass-to-volume ratio of the filter cake to the surface treatment agent solution is 1 g: (8-12) mL.

9. The preparation method according to claim 1, characterized in that, The reaction pH of S1 is not lower than 8; and / or the reaction temperature of S1 is 65℃-80℃; and / or the reaction time of S1 is 1 h-5 h.

10. The preparation method according to claim 1, characterized in that, The water-soluble nickel salt includes at least one of nickel sulfate, nickel chloride, nickel nitrate, and nickel acetate; and / or, the reducing agent includes at least one of sodium borohydride, potassium borohydride, and hydrazine hydrate.

11. The preparation method according to claim 1, characterized in that, The molar ratio of the reducing agent to the water-soluble nickel salt is (1.5-5):

1.

12. A nickel powder, characterized in that, The nickel powder is prepared by the preparation method according to any one of claims 1 to 11.

13. The application of the nickel powder according to claim 12 in conductive or catalytic materials.

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