Preparation method of nickel-plated magnesium powder and magnesium-based hydrogen storage alloy

Abstract

The invention discloses a preparation method of nickel-plated magnesium powder and a magnesium-based hydrogen storage alloy, and belongs to the technical field of hydrogen storage materials. The method comprises the following steps that magnesium powder is put into a chemical nickel plating solution for chemical nickel plating, a uniform and compact nickel layer is formed on the surface of the magnesium powder, and nickel-plated magnesium powder is obtained; the magnesium powder subjected to surface chemical nickel plating is dried in a vacuum drying box and mixed with other alloy element powder according to a certain proportion, the mixture is put into a ball mill to be subjected to mechanical alloying for a certain time, and mixed powder is obtained; carrying out compression molding on the mixed powder to obtain a green body; and sintering the green body in a protective atmosphere to obtain the magnesium-based hydrogen storage alloy, according to the method, the oxidation loss of the magnesium powder in the sintering process can be effectively reduced, and the yield of the magnesium-based hydrogen storage alloy is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen storage materials, and in particular to a method for preparing a magnesium-based hydrogen storage alloy, and in particular to a method for preparing the magnesium-based hydrogen storage alloy by chemically nickel-plating the surface of magnesium powder and then using a powder metallurgy method. Background Art

[0002] Magnesium-based hydrogen storage alloys have become one of the most promising hydrogen storage materials due to their high hydrogen storage capacity, abundant resources and low price. However, there are still some bottleneck problems in the practical application of magnesium-based hydrogen storage alloys, such as poor hydrogen absorption and desorption kinetics and poor cycle stability. In addition, in the preparation process of magnesium-based hydrogen storage alloys, magnesium powder is extremely easy to oxidize, causing the alloy composition to deviate from the design value, affecting the hydrogen storage performance of the alloy.

[0003] Traditional methods for preparing magnesium-based hydrogen storage alloys mainly include smelting and mechanical alloying. The smelting method has problems such as high energy consumption and serious component segregation; the mechanical alloying method has problems such as long preparation cycle and easy introduction of impurities; powder metallurgy, as a near-net forming technology, has the advantages of uniform composition, fine structure, and the ability to prepare parts with complex shapes. However, when preparing magnesium-based hydrogen storage alloys by powder metallurgy, although vacuum or atmosphere protection treatment is usually used in the mechanical alloying and sintering stages of the powder, magnesium powder is prone to oxidation during transportation and storage, and is even dangerous in high-temperature environments.

[0004] To this end, the present application proposes a method for preparing a magnesium-based hydrogen storage alloy by chemically plating nickel on the surface of magnesium powder and then using a powder metallurgy method. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art mentioned in the background technology, and to propose a method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy. The method can effectively reduce the oxidation loss of magnesium powder during mechanical alloying and sintering, and improve the yield of magnesium-based hydrogen storage alloy.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy comprises the following steps: S1. Electroless nickel plating on the surface of magnesium powder: placing magnesium powder in an electroless nickel plating solution for electroless nickel plating to form a uniform and dense nickel layer on the surface of the magnesium powder to obtain nickel-plated magnesium powder; S2, preparation of mixed powder: drying the magnesium powder after surface chemical nickel plating in a vacuum drying oven, mixing it with other alloy element powders in a certain proportion, loading it into a ball mill for mechanical alloying for a certain period of time, and obtaining a mixed powder; S3, powder pressing and molding: the mixed powder is loaded into a mold and pressed and molded under a certain pressure to obtain a green body; S4. Sintering: Sintering the green body in a protective atmosphere to obtain a magnesium-based hydrogen storage alloy.

[0007] As a further feature of the present invention, the chemical nickel plating solution in step 1 comprises: nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, etc.

[0008] As a further feature of the present invention, the temperature of the chemical nickel plating in step 1 is 60-90° C. and the time is 10-60 minutes.

[0009] As a further feature of the present invention, the other alloy element powders in step 2 include nickel powder, copper powder, iron powder, aluminum powder and rare earth powder (lanthanum powder, cerium powder, yttrium powder) and the like.

[0010] As a further feature of the present invention, the mechanical alloying for a certain period of time in step 2 is 0.5-2 hours.

[0011] As a further feature of the present invention, the pressure of the compression molding in step 3 is 100-500 MPa.

[0012] As a further feature of the present invention, in step 4, the sintering temperature is 400-600° C., and the sintering time is 1-5 hours.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. By chemically plating nickel on the surface of magnesium powder, the oxidation of magnesium powder during mechanical alloying and sintering can be effectively prevented, the loss of magnesium can be reduced, the oxygen content of the alloy can be reduced, and the yield of magnesium-based hydrogen storage alloy can be improved.

[0014] 2. The chemical nickel plating layer can improve the interface bonding between magnesium powder and other alloy element powders, and improve the density and mechanical properties of the alloy.

[0015] 3. The method of the present invention has simple process and is easy to realize industrial production. DETAILED DESCRIPTION

[0016] The content of the present invention can be more easily understood by selecting the following detailed description of the preferred implementation method of the present invention and the embodiments included. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the present invention belongs. When there is a conflict, the definition in this specification shall prevail.

[0017] As used herein, the term "prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0018] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0019] When amount, concentration or other value or parameter is expressed as range, preferred range or a series of upper preferred value and lower preferred value limit range, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing range "1 to 5", described range should be interpreted as including range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When numerical range is described in this article, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0020] Singular forms include plural references unless the context clearly indicates otherwise. "Optional" or "either" means that the subsequently described event or incident may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

[0021] Approximate terms in the specification and claims are used to modify quantities, indicating that the present invention is not limited to the specific quantity, but also includes acceptable and modified parts close to the quantity without causing changes in the relevant basic functions. Accordingly, the use of "about", "approximately", etc. to modify a numerical value means that the present invention is not limited to the exact numerical value. In some examples, the approximate terms may correspond to the accuracy of the instrument for measuring the numerical value. In the specification and claims of this application, range limitations can be combined and / or interchanged, and if not otherwise stated, these ranges include all subranges contained therein.

[0022] In addition, the indefinite articles "a" and "an" before the elements or components of the present invention have no restrictions on the quantity requirements (i.e. the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number is obviously intended to be in the singular form.

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] Embodiment 1 A method for preparing nickel-plated magnesium powder comprises placing magnesium powder in a chemical nickel plating solution for chemical nickel plating to form a uniform and dense nickel layer on the surface of the magnesium powder to obtain the nickel-plated magnesium powder.

[0025] Embodiment 2 A preparation method of a magnesium-based hydrogen storage alloy comprises the following steps: first drying nickel-plated magnesium powder in a vacuum drying oven, mixing the powder with other alloy element powders in a certain proportion, and loading the powder into a ball mill for mechanical alloying for a certain period of time to obtain a mixed powder; then loading the mixed powder into a mold, and pressing the mold under a certain pressure to obtain a green body; and then sintering the green body under a protective atmosphere to obtain a magnesium-based hydrogen storage alloy.

[0026] Embodiment 3 A method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy comprises the following steps: S1. Electroless nickel plating on the surface of magnesium powder: placing magnesium powder in an electroless nickel plating solution for electroless nickel plating to form a uniform and dense nickel layer on the surface of the magnesium powder to obtain nickel-plated magnesium powder; S11, the composition of the chemical nickel plating solution includes: nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, etc.; S12, the temperature of chemical nickel plating is 60-90°C, and the time is 10-60 minutes; S2, preparation of mixed powder: drying the magnesium powder after surface chemical nickel plating in a vacuum drying oven, mixing it with other alloy element powders in a certain proportion, loading it into a ball mill for mechanical alloying for a certain period of time, and obtaining a mixed powder; S21. Other alloy element powders include nickel powder, copper powder, iron powder, aluminum powder and rare earth powder (lanthanum powder, cerium powder, yttrium powder), etc. S22, mechanical alloying for a certain period of time is 0.5-2 hours; S3, powder pressing and molding: the mixed powder is loaded into a mold and pressed and molded under a certain pressure to obtain a green body; S31, the pressure of pressing is 100-500MPa; S4, sintering: sintering the green body under a protective atmosphere to obtain a magnesium-based hydrogen storage alloy; S41, the sintering temperature is 400-600°C, and the sintering time is 1-5 hours.

[0027] Embodiment 4 A method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy comprises the following steps: S1. Chemical nickel plating on the surface of magnesium powder: Put magnesium powder into a chemical nickel plating solution, the composition of which is 25g / L nickel sulfate, 30g / L sodium hypophosphite, 20g / L sodium citrate, and 15g / L sodium acetate. The temperature of the chemical nickel plating solution is 80°C and the time is 60 minutes. Perform chemical nickel plating to form a uniform and dense nickel layer on the surface of magnesium powder to obtain nickel-plated magnesium powder; S2. Preparation of mixed powder: The magnesium powder after chemical nickel plating on the surface was dried in a vacuum oven, mixed with nickel powder in an atomic ratio of 2:1, and loaded into a ball mill for mechanical alloying for 1 hour to obtain a mixed powder; S3 powder pressing: the mixed powder was loaded into a mold and pressed at a pressure of 200MPa to obtain a green body; S4. Sintering: The green body is sintered in a protective atmosphere at a sintering temperature of 400° C. for 3 hours to obtain a magnesium-based hydrogen storage alloy.

[0028] Embodiment 5 A method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy comprises the following steps: S1. Chemical nickel plating on the surface of magnesium powder: Put magnesium powder into a chemical nickel plating solution, the composition of which is 30g / L nickel sulfate, 20g / L sodium hypophosphite, 30g / L sodium citrate, and 10g / L sodium acetate. The temperature of the chemical nickel plating solution is 90°C and the time is 30 minutes. Perform chemical nickel plating to form a uniform and dense nickel layer on the surface of magnesium powder to obtain nickel-plated magnesium powder; S2. Preparation of mixed powder: The magnesium powder after chemical nickel plating was dried in a vacuum oven, mixed with nickel powder, aluminum powder and lanthanum powder in an atomic ratio of 75:15:7:3, and loaded into a ball mill for mechanical alloying for 1 hour to obtain a mixed powder; S3 powder pressing: the mixed powder was loaded into a mold and pressed at a pressure of 300MPa to obtain a green body; S4. Sintering: The green body is sintered in a protective atmosphere at a sintering temperature of 600° C. for 2 hours to obtain a magnesium-based hydrogen storage alloy.

[0029] The examples referred to herein are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to claim the widest possible range that can be imagined, and the embodiments presented herein are only illustrations of selected implementations according to the combination of all possible embodiments. Therefore, it is the applicant's intention that the appended claims are not limited by the selection of examples that illustrate the features of the present invention. Some numerical ranges used in the claims also include sub-ranges within them, and changes in these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy, characterized in that: The following steps are involved: S1, placing magnesium powder in a chemical nickel plating solution for chemical nickel plating, forming a uniform and dense nickel layer on the surface of the magnesium powder to obtain nickel-plated magnesium powder; S2, drying the magnesium powder after the surface chemical nickel plating in a vacuum drying oven, mixing it with other alloy element powders in a certain proportion, loading it into a ball mill for mechanical alloying for a certain period of time, and obtaining a mixed powder; S3, loading the mixed powder into a mold, and pressing and molding it under a certain pressure to obtain a green body; S4. Sintering the green body in a protective atmosphere to obtain a magnesium-based hydrogen storage alloy.

2. The method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy according to claim 1, characterized in that: In S1, the chemical nickel plating solution comprises: nickel sulfate, sodium hypophosphite, sodium citrate, and sodium acetate.

3. The method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy according to claim 2, characterized in that: The temperature of chemical nickel plating is 60-90°C and the time is 10-60 minutes.

4. The method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy according to claim 1, characterized in that: In S2, other alloy element powders include nickel powder, copper powder, iron powder, aluminum powder and rare earth powder, etc., among which the rare earth powder includes lanthanum powder, cerium powder, yttrium powder and the like.

5. The method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy according to claim 4, characterized in that: In S2, the mechanical alloying time is 0.5-2 hours.

6. The method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy according to claim 1, characterized in that: In S3, the pressure of the press molding is 100-500 MPa.

7. The method for preparing nickel-plated magnesium powder and magnesium-based hydrogen storage alloy according to claim 1, characterized in that: In S4, the sintering temperature is 400-600° C., and the sintering time is 1-5 hours.