A method for producing a nickel foil by electrolysis

Abstract

The application provides a method for producing nickel foil by electrolysis, which comprises the following steps: taking a noble metal plate as an anode, taking a titanium plate as a cathode, placing the anode and the cathode in an electrolyte, conducting electrolysis by passing direct current, electrodepositing a nickel metal layer on the titanium plate, and stripping the nickel metal layer to obtain the nickel foil; the electrolyte comprises water and the following components with the following concentrations: nickel sulfate 300-600 g / L; pH buffer 10-40 g / L; brightener 0.05-2 g / L; wetting agent 0.005-0.2 g / L; the pH of the electrolyte is 1-5; during the electrolysis process, the electrolysis temperature is 50-75 DEG C, and the current density is 20-80 A / dm 2 The method for producing nickel foil by electrolysis according to the application can obtain non-porous nickel foil with a smooth surface, low roughness and low thickness, and solves the problem that smooth and thin nickel foil cannot be obtained in the prior art.

Description

Technical Field

[0001] This invention relates to the field of electrochemical deposition technology, and more specifically, to a method for producing nickel foil by electrolysis. Background Technology

[0002] Nickel foil is a raw material used in industries such as electronics, telecommunications, and instrumentation. In recent years, the demand for thin nickel foil has been increasing daily, and its applications are becoming increasingly widespread. Currently, there are two main methods for producing nickel foil: rolling and electrolysis (electroforming). The rolling method produces nickel foil from thick to thin, requiring multiple rolling processes, resulting in a long production time, high costs, difficulty in obtaining thin foils, uneven thickness, and limitations on foil width. The electrolysis method, on the other hand, produces nickel foil from thin to thick, but through electrodeposition in a single step, resulting in a higher yield and lower processing costs. It is particularly suitable for producing wide and thin nickel foils. Electrolysis typically uses electrolytic nickel plates or scraps of electrolytic nickel as the anode, requiring the addition of nickel chloride as an anode activator, which corrodes equipment and is detrimental to long-term operation. Furthermore, the anode plate needs to be obtained through electrodeposition, increasing the production process and costs. CN103031578A discloses an electrolytic method for producing nickel foil, using a lead-silver plate or titanium plate as the anode and a sulfuric acid and boric acid as the electrolyte to prepare nickel foil, resulting in a smooth and flat nickel foil. However, the obtained nickel foil is relatively thick. Therefore, developing a smooth and flat thin nickel foil is of great significance. Summary of the Invention

[0003] The main objective of this invention is to provide a method for producing nickel foil by electrolysis, so as to solve the problem that it is impossible to obtain flat and smooth thin nickel foil in the prior art.

[0004] To achieve the above objectives, the present invention provides a method for producing nickel foil by electrolysis, using a noble metal plate as the anode and a titanium plate as the cathode, placing both the anode and cathode in an electrolyte, performing electrolysis by passing a direct current, and preparing nickel foil by electrodeposition on the titanium plate;

[0005] The electrolyte contains water and the following components at the following concentrations:

[0006] Nickel sulfate 300-600 g / L;

[0007] pH buffer 10–40 g / L;

[0008] Brightening agent 0.05~2g / L;

[0009] Wetting agent 0.005~0.2g / L;

[0010] The electrolyte pH is 1–5, the electrolysis temperature is 50–75℃, and the current density is 20–80 A / dm³. 2 .

[0011] Furthermore, the precious metal anode plate is selected from one of the following: platinum-rhodium, rhodium-iridium, or platinum-rhodium-iridium precious metal plates.

[0012] Furthermore, the wetting agent is selected from one or more of sodium dodecyl sulfate, sodium 2-ethylhexyl sulfate, sodium dihexyl succinate sulfonate, and sodium dipentyl succinate sulfonate.

[0013] Preferably, the wetting agent is selected from sodium dihexyl succinate or sodium dipentyl succinate, or a mixture of both.

[0014] Preferably, the concentration of the wetting agent is 0.05–0.1 g / L.

[0015] Furthermore, the brightening agent is selected from one or more of saccharin, 4-hydroxy-2-butynedi-2-hydroxyalkyl ether, 1,4-butynediol, 2-propynedi-2-hydroxyalkyl ether, sodium allyl sulfonate, propynyl alcohol, glyceryl monopropynyl ether, sodium sulfonyl propynyl ether salt and sodium sulfonate salt of carbonyl compounds.

[0016] Preferably, the concentration of the brightener is 0.2–2 g / L.

[0017] Furthermore, the pH buffer is selected from boric acid, sodium citrate, or a mixture of both.

[0018] Preferably, the concentration of the pH buffer is 30–40 g / L.

[0019] Furthermore, the concentration of nickel sulfate is 320–400 g / L.

[0020] Furthermore, the electrolyte has a pH of 2.5–4.5, an electrolysis temperature of 55–65°C, and a current density of 30–40 A / dm³. 2 .

[0021] Furthermore, the distance between the anode and cathode is 5–20 mm.

[0022] Preferably, the distance between the two poles is 10–20 mm.

[0023] Furthermore, the electrolysis time is 10–60 seconds.

[0024] Preferably, the electrolysis time is 20–30 seconds.

[0025] Furthermore, after removing the electrodeposited titanium plate from the electrolyte, it is sequentially cleaned and dried, and then the nickel metal layer formed after deposition is peeled off to obtain nickel foil.

[0026] By applying the technical solution of this invention, using a precious metal plate as the anode and a titanium plate as the cathode, and controlling the proportions of additives such as wetting agents, buffers, and brighteners, as well as the electrolysis conditions, nickel ions can be uniformly deposited on the entire cathode plate, thereby obtaining a non-porous nickel foil with low roughness and thinness. In addition, using a precious metal plate instead of a nickel plate as the anode avoids the pollution of the system caused by anode sludge generated by the anode, and directly electrolyzes nickel sulfate in the solution without the need to add nickel chloride, thus avoiding the influence of chloride ions on the electrolysis system. Moreover, the process is simple and the cost is low.

[0027] The electrolytic method of this invention for producing nickel foil can produce ultra-thin (thickness less than 5μm) nickel foil with a smooth surface, and the production method is friendly to equipment and the environment. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 The surface morphology of the nickel foil prepared in Example 1 of the present invention is shown;

[0030] Figure 2 The surface morphology of the nickel metal layer after electrolysis in Comparative Example 2 of the present invention is shown.

[0031] Figure 3 A surface morphology diagram of the nickel foil prepared in Comparative Example 4 of the present invention is shown;

[0032] Figure 4 A surface morphology diagram of the nickel foil prepared in Comparative Example 5 of the present invention is shown;

[0033] Figure 5 A surface morphology diagram of the nickel foil prepared in Comparative Example 6 of the present invention is shown. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0035] As described in the background section, existing technologies suffer from the inability to obtain smooth and flat thin nickel foils, especially ultra-thin nickel foils with a thickness of less than 5 μm. To address this issue, according to one aspect of the present invention, a method for producing nickel foil by electrolysis is provided. A noble metal plate is used as the anode, and a titanium plate as the cathode. Both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. Nickel foil is prepared by electrodeposition on the titanium plate. The electrolyte contains water and the following components at the following concentrations: nickel sulfate 300–600 g / L; pH buffer 10–40 g / L; brightener 0.05–2 g / L; wetting agent 0.005–0.2 g / L; the pH of the electrolyte is 1–5; during electrolysis, the electrolysis temperature is 50–75 °C, and the current density is 20–80 A / dm³. 2 .

[0036] To obtain non-porous nickel foil with low roughness and thinness, this invention provides a method for producing nickel foil by electrolysis. Using a precious metal plate as the anode and a titanium plate as the cathode, and by controlling the proportions of additives such as wetting agents, buffers, and brighteners, as well as the electrolysis conditions, nickel ions can be uniformly deposited across the entire cathode plate, resulting in non-porous nickel foil with low roughness and thinness. Furthermore, using a precious metal plate instead of a nickel plate as the anode avoids the pollution of the system caused by anode sludge. Direct electrolysis of nickel sulfate in the solution eliminates the need for adding nickel chloride, avoiding the influence of chloride ions on the electrolysis system. The process is simple and low-cost. The electrolytic method of this invention can produce ultra-thin (thickness less than 5 μm) nickel foil with a smooth surface, and this production method is equipment- and environmentally friendly.

[0037] In a preferred embodiment, the precious metal anode plate is selected from one of platinum-rhodium, rhodium-iridium, or platinum-rhodium-iridium precious metal plates. The above-mentioned precious metals have high hardness, good corrosion resistance, and long service life.

[0038] In a preferred embodiment, the wetting agent is selected from one or more of sodium dodecyl sulfate, sodium 2-ethylhexyl sulfate, sodium dihexyl succinate sulfonate, and sodium dipentyl succinate sulfonate; preferably, the wetting agent is selected from one or a mixture of sodium dihexyl succinate sulfonate or sodium dipentyl succinate sulfonate, which can promote more uniform precipitation of nickel ions across the entire cathode plate and reduce the probability of pinhole formation; in order to reduce costs and obtain high-quality ultrathin nickel foil, the concentration of the wetting agent is preferably 0.05 to 0.1 g / L.

[0039] In a preferred embodiment, the brightener is selected from one or more of saccharin, 4-hydroxy-2-butynedi-2-hydroxyalkyl ether, 1,4-butynediol, 2-propynedi-2-hydroxyalkyl ether, sodium allyl sulfonate, propynyl alcohol, glyceryl monopropynyl ether, sodium salt of sulfonylurea ether, and sodium salt of carbonyl compound sulfonate. The above brightener can not only refine the grain size of the coating and brighten the coating, but also better improve the stress distribution state of the coating and reduce the brittleness of the coating. Preferably, the concentration of the brightener is 0.2 to 2 g / L.

[0040] In a preferred embodiment, the pH buffer is selected from boric acid, sodium citrate, or a mixture of both; preferably, the concentration of the pH buffer is 30-40 g / L, which can better control the stability and uniformity of the electrolyte system coating in this invention and improve the surface morphology quality of the coating.

[0041] In a preferred embodiment, the concentration of nickel sulfate is 320–400 g / L. Under these conditions, a complete, smooth, and ultra-thin nickel foil can be formed, and the production cost is low.

[0042] At low pH levels, under the same electrolysis conditions, nickel foil exhibits thinner thickness, poorer mechanical properties, lower electrolysis efficiency, and higher energy consumption. Conversely, excessively high pH levels increase nickel foil roughness and degrade its performance. At low temperatures, nickel foil is difficult to form, while excessively high temperatures increase its roughness. To obtain smoother, thinner nickel foil with higher mechanical properties, while simultaneously reducing energy consumption, in a preferred embodiment, the electrolyte pH is 2.5–4.5, the electrolysis temperature is 55–65°C, and the current density is 30–40 A / dm³. 2 .

[0043] In order to obtain a smoother ultrathin nickel foil and higher production efficiency, in a preferred embodiment, the distance between the anode and cathode is 5 to 20 mm; preferably, the distance between the two electrodes is 10 to 20 mm.

[0044] In a preferred embodiment, the electrolysis time is 10–60 s; more preferably, the electrolysis time is 20–30 s, in order to obtain a smooth and dense ultrathin nickel foil.

[0045] In a preferred embodiment, after the electrodeposited titanium plate is removed from the electrolyte, it is sequentially cleaned and dried, and then the nickel metal layer formed after deposition is peeled off to obtain nickel foil.

[0046] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0047] Example 1

[0048] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0049] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 40 A / dm³. 2 The concentrations of each component in the electrolyte (solvent is water) are: NiSO4 350 g / L, H3BO3 40 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 1 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath, and the electrolysis time is 20 s. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. Figure 1 As shown, the nickel foil has a thickness of 4.89 μm, a surface roughness of Ra 0.245 μm, and a tensile strength of 866 N / mm². 2 The elongation rate is 8.2%.

[0050] Implement column 2

[0051] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0052] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 20 mm between the electrodes and a current density of 40 A / dm³. 2 The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 350 g / L, H3BO3 40 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 1 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath for 20 seconds. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. The nickel foil has a thickness of 4.96 μm, a roughness of Ra 0.207 μm, and a tensile strength of 846 N / mm². 2 The elongation rate is 8.4%.

[0053] Implement column 3

[0054] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0055] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 30 A / dm³. 2The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 350 g / L, H3BO3 40 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 1 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath for 20 seconds. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. The nickel foil has a thickness of 3.58 μm, a roughness of Ra 0.292 μm, and a tensile strength of 782 N / mm². 2 The elongation rate is 7.6%.

[0056] Implement column 4

[0057] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0058] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 40 A / dm³. 2 The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 350 g / L, H3BO3 40 g / L, sodium dipentyl succinate sulfonate 0.1 g / L, and saccharin 1 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath for 20 seconds. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. The nickel foil has a thickness of 4.76 μm, a roughness of Ra 0.179 μm, and a tensile strength of 782 N / mm². 2 The elongation rate is 7.6%.

[0059] Implementation of Column 5

[0060] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0061] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 40 A / dm³. 2The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 350 g / L, H3BO3 40 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 2 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath for 20 seconds. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. The nickel foil has a thickness of 4.56 μm, a roughness of Ra 0.198 μm, and a tensile strength of 846 N / mm². 2 The elongation rate is 8.9%.

[0062] Implement column 6

[0063] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0064] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 40 A / dm³. 2 The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 400 g / L, H3BO3 30 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 1 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath for 20 seconds. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. The nickel foil has a thickness of 4.81 μm, a roughness of Ra 0.249 μm, and a tensile strength of 782 N / mm². 2 The elongation rate is 7.6%.

[0065] Example 7

[0066] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0067] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 5 mm between the electrodes and a current density of 20 A / dm³. 2The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 300 g / L, H3BO3 10 g / L, sodium dipentyl succinate sulfonate 0.005 g / L, and 4-hydroxy-2-butynedi-2-hydroxyalkyl ether 0.05 g / L. The pH of the electrolyte is 2. The electrolysis temperature is maintained at 50℃ in a water bath, and the electrolysis time is 20 s. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. The nickel foil has a thickness of 2.91 μm, a roughness of Ra 0.379 μm, and a tensile strength of 613 N / mm². 2 The elongation rate is 6.9%.

[0068] Example 8

[0069] A method for producing nickel foil by electrolysis, the specific steps of which are as follows:

[0070] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 80 A / dm³. 2 The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 600 g / L, H3BO3 40 g / L, sodium dipentyl succinate sulfonate 0.1 g / L, and 1,4-butynediol 2 g / L. The pH of the electrolyte is 5. The electrolysis temperature is maintained at 75℃ in a water bath, and the electrolysis time is 60 s. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a bright, smooth, intact nickel foil without pinholes. The nickel foil has a thickness of 4.85 μm, a roughness of Ra 0.335 μm, and a tensile strength of 816 N / mm². 2 The elongation rate is 7.9%.

[0071] Example 9

[0072] The only difference from Example 1 is that the wetting agent, sodium dihexyl succinate sulfonate, is replaced with sodium dodecyl sulfate. The resulting nickel foil has a bright, smooth, intact surface free of pinholes, a thickness of 4.92 μm, a roughness Ra of 0.354 μm, and a tensile strength of 720 N / mm². 2 The elongation rate is 6.8%.

[0073] Example 10

[0074] The only difference between this example and Example 1 is that the wetting agent sodium dihexyl succinate sulfonate is replaced with sodium dipentyl succinate sulfonate.

[0075] The final product is a bright, smooth, and intact nickel foil free of pinholes, with a thickness of 4.37 μm, a surface roughness Ra of 0.228 μm, and a tensile strength of 898 N / mm². 2 The elongation rate is 8%.

[0076] Example 11

[0077] The only difference between this example and Example 1 is that the wetting agent sodium dihexyl succinate sulfonate is replaced with sodium 2-ethylhexyl sulfate.

[0078] The final product is a nickel foil with a bright, smooth, and intact surface free of pinholes. The nickel foil has a thickness of 4.74 μm, a surface roughness Ra of 0.396 μm, and a tensile strength of 628 N / mm². 2 The elongation rate is 7.2%.

[0079] Example 12

[0080] The only difference from Example 1 is the use of 500 g / L nickel sulfate. The final product is a bright, smooth, and intact nickel foil free of pinholes, with a thickness of 5.08 μm, a surface roughness Ra of 0.316 μm, and a tensile strength of 827 N / mm². 2 The elongation δ is 7.9%.

[0081] Example 13

[0082] The only difference between it and Example 1 is that the pH is 2.

[0083] The final product is a bright, smooth, and intact nickel foil free of pinholes. The foil thickness is 4.21 μm, the roughness Ra is 0.275 μm, and the tensile strength is 632 N / mm². 2 The elongation rate is 6.9%.

[0084] Example 14

[0085] The only difference between it and Example 1 is that the temperature is 75°C.

[0086] The final product is a nickel foil with a bright, smooth, and intact surface free of pinholes. The nickel foil has a thickness of 4.97 μm, a surface roughness Ra of 0.361 μm, and a tensile strength of 753 N / mm². 2 The elongation rate is 7.9%.

[0087] Example 15

[0088] The only difference between it and Example 1 is that the concentration of sodium dihexyl succinate sulfonate in the electrolyte during the preparation process is 0.2 g / L.

[0089] The final product is a nickel foil with a bright, smooth, and intact surface free of pinholes. The nickel foil has a thickness of 4.82 μm, a roughness of Ra 0.256 μm, and a tensile strength of 852 N / mm². 2 The elongation rate is 8.1%.

[0090] Comparative Example 1

[0091] The only difference between this and Example 1 is that the concentration of H3BO3 in the electrolyte is 2 g / L. The specific preparation steps are as follows:

[0092] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 40 A / dm³. 2 The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 350 g / L, H3BO3 2 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 1 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath for 20 seconds. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a nickel foil with a thickness of 5.02 μm, a roughness of Ra 0.937 μm, and a tensile strength of 637 N / mm². 2 The elongation rate is 6.3%.

[0093] Comparative Example 2

[0094] The difference between this and Example 1 is that the water bath temperature is 40°C, and the specific steps are as follows:

[0095] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate. The distance between the two plates is 10 mm, and the current density is 40 A / dm³. 2 The concentrations of each component in the electrolyte (solvent: water) were: NiSO4 350 g / L, H3BO3 40 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 1 g / L. The pH of the electrolyte was 3. The electrolysis temperature was maintained at 40℃ in a water bath, and the electrolysis time was 20 seconds. After electrolysis, the nickel metal layer peeled, cracked, and became misshapen. Figure 2 As shown.

[0096] Comparative Example 3

[0097] The only difference between this example and Example 1 is that the concentration of H3BO3 in the electrolyte is 2 g / L, and the electrolysis time is 60 s. The specific steps are as follows:

[0098] Using a platinum-rhodium plate as the anode and a titanium plate as the cathode, both the anode and cathode are placed in an electrolyte, and electrolysis is performed by applying a direct current. A nickel metal layer is electrodeposited on the titanium plate, with a distance of 10 mm between the electrodes and a current density of 40 A / dm³. 2 The electrolyte (solvent is water) contains the following components at the following concentrations: NiSO4 350 g / L, H3BO3 2 g / L, sodium dipentyl succinate sulfonate 0.05 g / L, and saccharin 1 g / L. The pH of the electrolyte is 3. The electrolysis temperature is maintained at 60℃ in a water bath for 60 seconds. After electrolysis, the titanium plate with the electrodeposited nickel metal layer is removed from the electrolyte and washed with water. After cleaning, it is dried to remove water. After drying, the nickel metal layer is peeled off to obtain a nickel foil with a thickness of 14.96 μm, a roughness of Ra 0.332 μm, and a tensile strength of 795 N / mm². 2 The elongation rate is 7.4%.

[0099] Comparative Example 4

[0100] The only difference between it and Example 1 is that the electrolyte does not contain the wetting agent sodium dihexyl succinate sulfonate.

[0101] The final nickel foil has a thickness of 4.98 μm, a roughness of Ra 0.694 μm, and a tensile strength of 628 N / mm. 2 The elongation was 7.2%, and tiny pinholes appeared in the nickel foil, such as... Figure 3 As shown.

[0102] Comparative Example 5

[0103] The only difference between it and Example 1 is that the concentration of sodium dihexyl succinate sulfonate in the electrolyte is 0.003 g / L.

[0104] The final nickel foil has a thickness of 4.74 μm, a roughness of Ra 0.372 μm, and a tensile strength of 754 N / mm. 2 The elongation was 7.6%, and a small number of pinholes appeared in the nickel foil, such as... Figure 4 As shown.

[0105] Comparative Example 6

[0106] The only difference from Example 1 is the use of 200 g / L nickel sulfate. The nickel metal layer was not formed after electrolysis, as shown below. Figure 5 As shown.

[0107] The roughness of the nickel foil was measured using a roughness tester according to standard ISO8503, the thickness of the nickel foil was measured using a film thickness tester according to standard GB / T36053-2018, and the tensile strength and elongation of the nickel foil were tested using a tensile strength tester according to GB / T228.

[0108] From the nickel foil thickness data, roughness data, tensile strength and elongation data of Examples 1-15 and Comparative Examples 1-6, it can be seen that, compared with Comparative Examples 1-6, Examples 1-11, through the control of the ratio of additives such as wetting agents, buffers, and brighteners, as well as electrolysis conditions such as temperature, pH and current density, prepared nickel foils with both low roughness and low thickness and good mechanical properties. The nickel foil thickness (2.91-4.96 μm) is less than 5 μm, and the roughness (Ra0.179-Ra0.396 μm) is less than Ra0.4 μm. Furthermore, data from Examples 1-15 and Comparative Examples 1-6 show that the addition of appropriate amounts of buffer and wetting agent in the electrolyte system can promote the uniform deposition of nickel ions across the entire cathode plate, forming a dense structure and reducing the roughness of the nickel foil. In particular, when sodium dihexyl succinate or sodium dipentyl succinate is used as the wetting agent (see Examples 1 and 9-11), the roughness of the nickel foil is significantly reduced. A comparison of Comparative Examples 4, 5, and 1 shows that without the addition of a wetting agent or with insufficient addition of sodium dihexyl succinate, pinholes appear on the nickel foil, resulting in an incomplete surface. A comparison of Comparative Examples 1, 3, and 1 shows that with insufficient addition of the buffer H3BO3, an increased electrolysis time is required to obtain a nickel foil with lower roughness, leading to excessively thick nickel foil. Furthermore, when the water bath temperature is too low, the nickel metal layer peels and breaks, failing to take shape (see Comparative Example 2). When the nickel sulfate concentration is too low, the nickel metal layer fails to take shape after electrolysis (see Comparative Example 6).

[0109] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for producing nickel foil by electrolysis, characterized in that, Using a precious metal plate as the anode and a titanium plate as the cathode, both the anode and the cathode are placed in an electrolyte, and electrolysis is performed by passing a direct current. Nickel foil is prepared by electrodeposition on the titanium plate. The electrolyte contains water and the following components at the following concentrations: Nickel sulfate 300-600 g / L; pH buffer 10–40 g / L; Brightening agent 0.05~2g / L; Wetting agent 0.005~0.2g / L; The electrolyte has a pH of 1–5, and the electrolysis process is carried out at a temperature of 50–75°C and a current density of 20–80 A / dm³. 2 ; The wetting agent is selected from one or more of sodium dodecyl sulfate, sodium 2-ethylhexyl sulfate, sodium dihexyl succinate sulfonate, and sodium dipentyl succinate sulfonate; the brightening agent is selected from one or more of saccharin, 4-hydroxy-2-butynedi-2-hydroxyalkyl ether, 1,4-butynediol, 2-propynedi-2-hydroxyalkyl ether, sodium allyl sulfonate, propynyl alcohol, glyceryl monopropynyl ether, sodium sulfonyl propynyl ether, and sodium sulfonate of carbonyl compounds.

2. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The precious metal anode plate is selected from one of the following: platinum-rhodium, rhodium-iridium, or platinum-rhodium-iridium precious metal plates.

3. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The wetting agent is selected from one or a mixture of sodium dihexyl succinate sulfonate and sodium dipentyl succinate sulfonate. The concentration of the wetting agent is 0.05–0.1 g / L.

4. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The concentration of the brightener is 0.2–2 g / L.

5. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The pH buffer is selected from boric acid, sodium citrate, or a mixture of both. The concentration of the pH buffer is 30–40 g / L.

6. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The concentration of the nickel sulfate is 320–400 g / L.

7. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The electrolyte has a pH of 2.5–4.5, the electrolysis temperature is 55–65°C, and the current density is 30–40 A / dm³. 2 .

8. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The distance between the anode and the cathode is 5–20 mm.

9. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, The distance between the anode and the cathode is 10-20 mm.

10. The method for producing nickel foil by electrolysis according to any one of claims 1 to 9, characterized in that, The electrolysis time is 10–60 seconds.

11. The method for producing nickel foil by electrolysis according to any one of claims 1 to 9, characterized in that, The electrolysis time is 20 to 30 seconds.

12. The method for producing nickel foil by electrolysis according to claim 1, characterized in that, After the electrodeposited titanium plate is removed from the electrolyte, it is cleaned and dried in sequence. Then, the metal layer formed after deposition is peeled off to obtain the nickel foil.

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