Electrolyte for preparing nickel-iron alloy foil and application

Abstract

The invention relates to the technical field of alloy foil manufacturing, in particular to electrolyte for preparing nickel-iron alloy foil and application. The embodiment of the invention discloses an electrolyte for preparing a nickel-iron alloy foil and application. The electrolyte comprises 200-400 parts by mass of metal nickel salt, 20-80 parts by mass of metal iron salt, 0.025-0.100 part by mass of chlorine salt, 2-15 parts by mass of a reducing agent, 30-50 parts by mass of an acid-base regulator, 50-70 parts by mass of a metal complexing agent, 2-16 parts by mass of a brightening agent and 0.2-0.5 part by mass of a wetting agent. The concentration of chloride ions in the electrolyte is controlled within a low range, and the adding proportion of the reducing agent, the acid-base regulator, the metal complexing agent, the brightener and the wetting agent is controlled, so that the tensile strength and the ductility of the nickel-iron alloy foil are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alloy foil manufacturing, in particular to an electrolyte for preparing a nickel-iron alloy foil and application thereof. BACKGROUND

[0002] The nickel-iron alloy foil is an alloy material with good electrical properties, mechanical properties, corrosion resistance and soft magnetic properties, and is widely used in the electronic and electrical industries, especially in the fields of communication, radar, electronic computers and automatic control instruments. With the progress of science and technology, the materials required by many high-tech fields are developing towards lightness and thinness. In recent years, electrodeposited micron-level nickel-iron alloy foils have become a research hotspot for battery current collector materials due to their lightness, excellent physical properties and good electrical conductivity. The preparation of nickel-iron alloy foils by electrodeposition has the advantages of isotropy in physical properties, easy thickness control and low production cost, and the research on electrodeposited nickel-iron alloy foils has a very broad application prospect.

[0003] At present, how to improve the tensile strength and elongation of the nickel-iron alloy foil has become a technical problem to be solved in the field. SUMMARY

[0004] Therefore, the present application provides an electrolyte for preparing a nickel-iron alloy foil and application thereof to solve the technical problem of how to improve the tensile strength and elongation of the nickel-iron alloy foil in the prior art.

[0005] In a first aspect, an embodiment of the present application provides an electrolyte for preparing a nickel-iron alloy foil, which comprises 200-400 parts by mass of a nickel salt, 20-80 parts by mass of a metal iron salt, 0.025-0.100 parts by mass of a chloride salt, 2-15 parts by mass of a reducing agent, 30-50 parts by mass of an acid-base adjusting agent, 50-70 parts by mass of a metal complexing agent, 2-16 parts by mass of a brightener and 0.2-0.5 parts by mass of a wetting agent.

[0006] Optionally, the electrolyte for preparing the nickel-iron alloy foil comprises 200-400 parts by mass of nickel sulfate hexahydrate, 50-80 parts by mass of ferrous sulfate heptahydrate and 0.025-0.075 parts by mass of sodium chloride.

[0007] Optionally, the reducing agent comprises ascorbic acid, the acid-base adjusting agent comprises boric acid, the metal complex comprises sodium citrate, the brightener comprises sodium saccharin and the wetting agent comprises sodium dodecyl sulfate.

[0008] In a second aspect, an embodiment of the present application provides a preparation method of a nickel-iron alloy foil, which comprises:

[0009] The electrolyte for preparing the nickel-iron alloy foil is supplied between the anode plate and the cathode roller, and a voltage is applied between the anode plate and the cathode roller, and the electrolysis of the electrolyte for preparing the nickel-iron alloy foil is carried out to form the nickel-iron alloy foil on the surface of the cathode roller.

[0010] Optionally, the current density applied between the anode plate and the cathode roller during electrolysis is 10-20 A / dm 2 .

[0011] Optionally, the pH value of the electrolyte for preparing the nickel-iron alloy foil during electrolysis is 2-3.

[0012] Optionally, the temperature of the electrolyte for preparing the nickel-iron alloy foil during electrolysis is 50-60°C.

[0013] Optionally, the average roughness of the cathode roller is 0.12-0.17 μm, the rotating speed of the cathode roller during electrolysis is 7.5-8.4 m / min, the cathode roller is a titanium roller, and the anode plate is an iridium-plated titanium plate.

[0014] In a third aspect, an embodiment of the present application provides a nickel-iron alloy foil obtained by the above method for preparing a nickel-iron alloy foil.

[0015] In a fourth aspect, an embodiment of the present application provides a lithium ion battery negative material comprising the above nickel-iron alloy foil.

[0016] The electrolyte for preparing a nickel-iron alloy foil and the application thereof according to the embodiments of the present application comprise 200-400 parts by mass of a metal nickel salt, 20-80 parts by mass of a metal iron salt, 0.025-0.100 parts by mass of a chlorine salt, 2-15 parts by mass of a reducing agent, 30-50 parts by mass of an acid-base adjusting agent, 50-70 parts by mass of a metal complexing agent, 2-16 parts by mass of a brightener, and 0.2-0.5 parts by mass of a wetting agent. By controlling the concentration of chloride ions in the electrolyte within a lower range and controlling the addition ratio of the reducing agent, the acid-base adjusting agent, the metal complexing agent, the brightener, and the wetting agent, the tensile strength and the elongation of the nickel-iron alloy foil can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The figure is a tensile strength result graph of the nickel-iron alloy foils of Embodiments 1-5 of the present application.

[0018] Figure 2 The figure is an elongation result graph of the nickel-iron alloy foils of Embodiments 1-5 of the present application.

[0019] Figure 3 The figure is an EDS analysis result graph of the bright surface of the nickel-iron alloy foil of Embodiment 12 of the present application.

[0020] Figure 4 An EDS analysis result graph of the rough surface of the nickel-iron alloy foil of Example 12 of the present application. DETAILED DESCRIPTION

[0021] For the purposes of this application, reference will be made to the accompanying drawings in which preferred embodiments of the application are illustrated. The application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.

[0022] It is to be understood that where the terms "including", "includes", "having", "has", "e.g.", "involving", "including" or other similar forms are used in the detailed description, they are meant to be inclusive, rather than to reference any in limitation.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0024] In the related art, the concentration of chloride ions in the electrolyte for the nickel-iron alloy foil is generally greater than 10 g / L, for example, the concentration of chloride ions is generally 12 g / L to 15 g / L. Maintaining the concentration of chloride ions in the above range can improve the efficiency of electrodeposition to improve the quality of the obtained nickel-iron alloy foil.

[0025] An embodiment of the present application provides an electrolyte for preparing a nickel-iron alloy foil, comprising 200 to 400 parts by mass of a metal nickel salt, 20 to 80 parts by mass of a metal iron salt, 0.025 to 0.100 parts by mass of a chloride salt, 2 to 15 parts by mass of a reducing agent, 30 to 50 parts by mass of an acid-base adjusting agent, 50 to 70 parts by mass of a metal complexing agent, 2 to 16 parts by mass of a brightener, and 0.2 to 0.5 parts by mass of a wetting agent.

[0026] The metal nickel salt is used to provide metal nickel ions in the electrolysis process, the metal iron salt is used to provide metal ferrous ions in the electrolysis process; the chloride ions can reduce the valence of metal active sites, and the chloride ions provided by the chloride salt are used to reduce the electrodeposition polarization in the electrolysis process; the reducing agent is used to prevent the oxidation of ferrous ions in the electrolysis process, the acid-base regulator is used to control the electrolytic acidic environment in the electrolysis process, and the metal complex is used to complex with metal ions to make the nickel ions and ferrous ions electrodeposited in the electrolysis process; the brightener can inhibit the rapid and disordered deposition of metal ions by being adsorbed on the surface of the cathode (nickel-iron alloy foil), promote the uniform formation of crystal nuclei, thereby refining the plating layer grains, and make the surface more dense and smooth; and the wetting agent can significantly reduce the surface tension of the electrolyte, so that the electrolyte can more easily wet the surface of the cathode (nickel-iron alloy foil), that is, the surface tension of the nickel-iron alloy foil is reduced, so that the liquid can spread on the surface of the nickel-iron alloy foil to wet the nickel-iron alloy foil.

[0027] In the embodiment, the mass fraction of the chloride salt is relatively low, by controlling the concentration of chloride ions in the electrolyte within a relatively low range and controlling the addition proportion of the reducing agent, the acid-base regulator, the metal complexing agent, the brightener and the wetting agent, the great reduction of the concentration of chloride ions does not reduce the quality of the nickel-iron alloy foil obtained by electrolysis, but on the contrary, is conducive to improving the tensile strength and elongation of the nickel-iron alloy foil.

[0028] In addition, the content of iron in the electrolyte formula is relatively high, which is conducive to increasing the content of iron in the nickel-iron alloy foil. While the content of iron is increased and the content of nickel is reduced, the obtained nickel-iron alloy foil still has good tensile strength and elongation.

[0029] For example, in the above-mentioned electrolyte for preparing a nickel-iron alloy foil, the concentration of the metal nickel salt is 200-400 g / L, the concentration of the metal iron salt is 20-80 g / L, the concentration of the chloride salt is 0.025-0.100 g / L, the concentration of the reducing agent is 2-15 g / L, the concentration of the acid-base regulator is 30-50 g / L, the concentration of the metal complexing agent is 50-70 g / L, the concentration of the brightener is 2-16 g / L, and the concentration of the wetting agent is 0.2-0.5 g / L.

[0030] In the embodiment, the concentration of chloride ions in the electrolyte is 0.025-0.100 g / L, which can reduce the corrosiveness of the electrolyte without reducing the tensile strength and elongation of the nickel-iron alloy foil, and is conducive to reducing the synthesis difficulty of the nickel-iron alloy foil.

[0031] As an embodiment, the metal nickel salt is nickel sulfate hexahydrate, the metal iron salt is ferrous sulfate heptahydrate, and the chloride salt is sodium chloride, that is, the above-mentioned electrolyte for preparing a nickel-iron alloy foil comprises 200-400 mass parts of nickel sulfate hexahydrate, 50-80 mass parts of ferrous sulfate heptahydrate and 0.025-0.075 mass parts of sodium chloride.

[0032] As an embodiment, the reducing agent includes ascorbic acid, the acid-base regulator includes boric acid, the metal complex includes sodium citrate, the brightener includes sodium saccharin, and the wetting agent includes sodium dodecyl sulfate.

[0033] The application provides a preparation method of a nickel-iron alloy foil of an embodiment, including the steps of:

[0034] Step S11: providing the electrolyte for preparing the nickel-iron alloy foil as described above.

[0035] The electrolyte for preparing the nickel-iron alloy foil is described above and will not be described here.

[0036] Step S12: supplying the electrolyte for preparing the nickel-iron alloy foil as described above between the anode plate and the cathode roller, and applying a voltage between the anode plate and the cathode roller to electrolyze the electrolyte for preparing the nickel-iron alloy foil to form the nickel-iron alloy foil on the surface of the cathode roller.

[0037] During the electrolysis, the nickel ions and ferrous ions in the electrolyte are deposited on the surface of the cathode roller to form the nickel-iron alloy foil, which is peeled off from the cathode roller and enters the subsequent processing procedure.

[0038] In this embodiment, the mass fraction of the chlorine salt is relatively low. By controlling the concentration of the chlorine ions in the electrolyte within a relatively low range and controlling the addition proportions of the reducing agent, the acid-base regulator, the metal complex, the brightener, and the wetting agent, the great reduction of the concentration of the chlorine ions does not reduce the quality of the nickel-iron alloy foil obtained by electrolysis, but rather helps to improve the tensile strength and elongation of the nickel-iron alloy foil.

[0039] As an embodiment, the current density applied between the anode plate and the cathode roller during the electrolysis is 10-20 A / dm 2 .

[0040] In this embodiment, the electrolysis is performed at a relatively low current density, and the deposition is relatively slow. The slow deposition allows the grains to grow fully, and the structure is uniform and dense. In addition, the use of a relatively low current density in combination with the dosage control of the brightener allows the grains to grow fully to form a uniform and dense structure while relieving the problem of increased roughness of the foil surface caused by low current density, so that the surface roughness of the alloy foil is within a reasonable range.

[0041] As an embodiment, the pH value of the electrolyte for preparing the nickel-iron alloy foil during the electrolysis is 2-3.

[0042] In this embodiment, the use of the acid-base regulator can keep the pH value of the electrolyte within the above range during the electrolysis.

[0043] As an embodiment, the temperature of the electrolyte used for preparing the nickel-iron alloy foil during electrolysis is 50-60°C.

[0044] In the present embodiment, controlling the electrolysis temperature within the above range is advantageous for increasing the compactness of the alloy foil coating while ensuring the deposition rate.

[0045] As an embodiment, the average roughness of the cathode roller can be 0.12-0.17 μm. In the present embodiment, controlling the roughness of the cathode roller within the above range is advantageous for the formation of the crystal phase structure of the alloy foil obtained by electrolysis at a thickness of 0-1.5 μm.

[0046] In some embodiments, the rotation speed of the cathode roller during electrolysis is 7.5-8.4 m / min.

[0047] In some embodiments, the cathode roller is a titanium roller and the anode plate is an iridium-plated titanium plate, i.e., the anode plate is formed by plating a layer of metallic iridium on the surface of a titanium plate.

[0048] The present embodiment provides a nickel-iron alloy foil obtained according to the method for preparing a nickel-iron alloy foil described above.

[0049] The present embodiment provides a lithium ion battery negative electrode material comprising the nickel-iron alloy foil described above.

[0050] Example 1

[0051] The present embodiment provides a method for preparing a nickel-iron alloy foil, comprising the steps of:

[0052] Step 1: providing the electrolyte for preparing a nickel-iron alloy foil described above.

[0053] Table 1: Content table of each component in Example 1

[0054]

[0055] In the present embodiment, the content of each component in the electrolyte for preparing a nickel-iron alloy foil is shown in Table 1.

[0056] Step 2: supplying the electrolyte for preparing a nickel-iron alloy foil described above between the anode plate and the cathode roller, and applying a voltage between the anode plate and the cathode roller, and electrolyzing the electrolyte for preparing a nickel-iron alloy foil to form the nickel-iron alloy foil on the surface of the cathode roller.

[0057] In the present embodiment, the current density applied between the anode plate and the cathode roller during electrolysis is 20 A / dm 2 , the electrolysis temperature is 55°C, the pH value during electrolysis is 3, and the rotation speed of the cathode roller during electrolysis is 7.5-8.4 m / min.

[0058] Example 2

[0059] The present embodiment provides a method for preparing a ferronickel alloy foil, comprising the steps of:

[0060] Step 1: providing the electrolyte for preparing a ferronickel alloy foil as described above.

[0061] Table 2: Ingredient content table of Example 2

[0062]

[0063] The ingredients of the electrolyte for preparing a ferronickel alloy foil are shown in Table 2.

[0064] Step 2: supplying the electrolyte for preparing a ferronickel alloy foil as described above between the anode plate and the cathode roller, and applying a voltage between the anode plate and the cathode roller, electrolyzing the electrolyte for preparing a ferronickel alloy foil to form the ferronickel alloy foil on the surface of the cathode roller.

[0065] The current density applied between the anode plate and the cathode roller during electrolysis is 20 A / dm 2 , the electrolysis temperature is 55°C, the pH value during electrolysis is 3, and the rotation speed of the cathode roller during electrolysis is 7.5-8.4 m / min.

[0066] Example 3

[0067] The present embodiment provides a method for preparing a ferronickel alloy foil, comprising the steps of:

[0068] Step 1: providing the electrolyte for preparing a ferronickel alloy foil as described above.

[0069] Table 3: Ingredient content table of Example 3

[0070]

[0071] The ingredients of the electrolyte for preparing a ferronickel alloy foil are shown in Table 3.

[0072] Step 2: supplying the electrolyte for preparing a ferronickel alloy foil as described above between the anode plate and the cathode roller, and applying a voltage between the anode plate and the cathode roller, electrolyzing the electrolyte for preparing a ferronickel alloy foil to form the ferronickel alloy foil on the surface of the cathode roller.

[0073] The current density applied between the anode plate and the cathode roller during electrolysis is 20 A / dm 2 , the electrolysis temperature is 55°C, the pH value during electrolysis is 3, and the rotation speed of the cathode roller during electrolysis is 7.5-8.4 m / min.

[0074] Example 4

[0075] The present embodiment provides a method for preparing a ferronickel alloy foil, comprising the steps of:

[0076] Step 1: providing the electrolyte for preparing the nickel-iron alloy foil as described above.

[0077] Table 4: content table of each component of Example 4

[0078]

[0079] The content of each component of the electrolyte for preparing the nickel-iron alloy foil is shown in Table 4.

[0080] Step 2: supplying the electrolyte for preparing the nickel-iron alloy foil as described above between the anode plate and the cathode roller, and applying a voltage between the anode plate and the cathode roller, and electrolyzing the electrolyte for preparing the nickel-iron alloy foil to form the nickel-iron alloy foil on the surface of the cathode roller.

[0081] The current density applied between the anode plate and the cathode roller during electrolysis is 20 A / dm 2 , the electrolysis temperature is 55℃, the pH value during electrolysis is 3, and the rotating speed of the cathode roller during electrolysis is 7.5-8.4 m / min.

[0082] Example 5

[0083] The present embodiment provides a method for preparing a nickel-iron alloy foil, comprising the steps of:

[0084] Step 1: providing the electrolyte for preparing the nickel-iron alloy foil as described above.

[0085] Table 5: content table of each component of Example 5

[0086]

[0087] The content of each component of the electrolyte for preparing the nickel-iron alloy foil is shown in Table 5.

[0088] Step 2: supplying the electrolyte for preparing the nickel-iron alloy foil as described above between the anode plate and the cathode roller, and applying a voltage between the anode plate and the cathode roller, and electrolyzing the electrolyte for preparing the nickel-iron alloy foil to form the nickel-iron alloy foil on the surface of the cathode roller.

[0089] The current density applied between the anode plate and the cathode roller during electrolysis is 20 A / dm 2 , the electrolysis temperature is 55℃, the pH value during electrolysis is 3, and the rotating speed of the cathode roller during electrolysis is 7.5-8.4 m / min.

[0090] The thickness of the nickel-iron alloy foil prepared in Example 1 to Example 5 is 6 μm, and the experimental results of Example 1 to Example 5 are shown in Figure 1 and Figure 2 as shown in Figure 1As shown in Table 1, when the concentration of chloride ions in the electrolyte is 0.025 g / L to 0.10 g / L, the tensile strength of the nickel-iron alloy foil can reach 1550 MPa or more; when the concentration of chloride ions in the electrolyte is 0.025 g / L, the tensile strength of the nickel-iron alloy foil can reach 1700 MPa or more. As shown in Table 2, Figure 2 As shown in Table 3, when the concentration of chloride ions in the electrolyte is 0.025 g / L to 0.10 g / L, the elongation of the nickel-iron alloy foil can reach 2.8% or more; when the concentration of chloride ions in the electrolyte is 0.050 g / L, the elongation of the nickel-iron alloy foil can reach 3.0% or more.

[0091] Examples 6 to 12

[0092] The method for preparing the nickel-iron alloy foil comprises the steps of:

[0093] Step 1: providing the above-mentioned electrolyte for preparing the nickel-iron alloy foil.

[0094] Table 6: Content table of each component in Examples 6 to 12

[0095]

[0096] Step 2: supplying the above-mentioned electrolyte for preparing the nickel-iron alloy foil between the anode plate and the cathode roller, and applying a voltage between the anode plate and the cathode roller, electrolyzing the electrolyte for preparing the nickel-iron alloy foil to form the nickel-iron alloy foil on the surface of the cathode roller.

[0097] In the above method, the current density applied between the anode plate and the cathode roller during electrolysis is 20 A / dm 2 , the electrolysis temperature is 55°C, the pH value during electrolysis is 3, and the rotating speed of the cathode roller during electrolysis is 7.5-8.4 m / min.

[0098] The thickness of the nickel-iron alloy foil prepared in Examples 6 to 12 is 6 μm, the tensile strength of the nickel-iron alloy foil prepared in Examples 6 to 12 can reach 1700 MPa or more, and the elongation of the nickel-iron alloy foil prepared in Examples 6 to 12 can reach 2.8% or more.

[0099] As shown in Table 1, when the concentration of chloride ions in the electrolyte is 0.025 g / L to 0.10 g / L, the tensile strength of the nickel-iron alloy foil can reach 1550 MPa or more; when the concentration of chloride ions in the electrolyte is 0.025 g / L, the tensile strength of the nickel-iron alloy foil can reach 1700 MPa or more. As shown in Table 2, Figure 3 and Figure 4 As shown in Table 3, when the concentration of chloride ions in the electrolyte is 0.025 g / L to 0.10 g / L, the elongation of the nickel-iron alloy foil can reach 2.8% or more; when the concentration of chloride ions in the electrolyte is 0.050 g / L, the elongation of the nickel-iron alloy foil can reach 3.0% or more.

[0100] The technical features of the above examples can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above examples are described, however, as long as the combinations of the technical features do not contradict each other, they should be considered as falling within the scope of the present disclosure.

[0101] The above embodiments only express the preferred embodiments of the present application, which are described in a more specific and detailed manner, but should not be construed as limiting the scope of the patent application. It should be noted that for ordinary skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. An electrolyte for preparing nickel-iron alloy foil, characterized in that, It includes 200-400 parts by weight of nickel salt, 20-80 parts by weight of iron salt, 0.025-0.100 parts by weight of chloride salt, 2-15 parts by weight of reducing agent, 30-50 parts by weight of acid-base regulator, 50-70 parts by weight of metal complexing agent, 2-16 parts by weight of brightener, and 0.2-0.5 parts by weight of wetting agent.

2. The electrolyte for preparing nickel-iron alloy foil according to claim 1, characterized in that, The electrolyte used to prepare nickel-iron alloy foil comprises 200-400 parts by weight of nickel sulfate hexahydrate, 50-80 parts by weight of ferrous sulfate heptahydrate, and 0.025-0.075 parts by weight of sodium chloride.

3. The electrolyte for preparing nickel-iron alloy foil according to claim 1, characterized in that, The reducing agent includes ascorbic acid, the acid-base regulator includes boric acid, the metal complex includes sodium citrate, the brightener includes sodium saccharin, and the wetting agent includes sodium dodecyl sulfate.

4. A method for preparing a nickel-iron alloy foil, characterized in that, include: An electrolyte for preparing nickel-iron alloy foil according to any one of claims 1 to 3 is supplied between an anode plate and a cathode roller, and a voltage is applied between the anode plate and the cathode roller to electrolyze the electrolyte for preparing nickel-iron alloy foil to form the nickel-iron alloy foil on the surface of the cathode roller.

5. The method for preparing nickel-iron alloy foil according to claim 4, characterized in that, The current density applied between the anode plate and the cathode roller during electrolysis is 10–20 A / dm². 2 .

6. The method for preparing nickel-iron alloy foil according to claim 4, characterized in that, The pH value of the electrolyte used to prepare nickel-iron alloy foil during electrolysis is 2 to 3.

7. The method for preparing nickel-iron alloy foil according to claim 4, characterized in that, The temperature of the electrolyte used to prepare the nickel-iron alloy foil during electrolysis is 50℃~60℃.

8. The method for preparing nickel-iron alloy foil according to claim 4, characterized in that, The cathode roller has an average roughness of 0.12 to 0.17 μm, and the rotational speed of the cathode roller during electrolysis is 7.5 to 8.4 m / min. The cathode roller is a titanium roller, and the anode plate is an iridium-plated titanium plate.

9. A nickel-iron alloy foil, characterized in that, The nickel-iron alloy foil is obtained according to the preparation method of nickel-iron alloy foil as described in any one of claims 4 to 8.

10. A lithium-ion battery anode material, characterized in that, Including the nickel-iron alloy foil as described in claim 9.

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