Method for electrodepositing nickel and electrodeposited nickel plate

Abstract

The invention provides a nickel electro-deposition method and an electro-deposition nickel plate, and the method comprises the following steps: carrying out first electro-deposition in first electro-deposition liquid to obtain a nickel starting sheet; taking the obtained nickel starting sheet as a cathode, and carrying out second electro-deposition in a second electro-deposition solution to obtain an electro-deposition nickel plate; wherein the first electro-deposition liquid and the second electro-deposition liquid are in flowing in and out states; the Ni < 2 + > concentration of the first electro-deposition liquid at the inlet is higher than the Ni < 2 + > concentration of the second electro-deposition liquid at the inlet; according to the method, first electro-deposition liquid has high nickel ion concentration at an inlet, and low current density is adopted in first electro-deposition; the second electro-deposition liquid has low nickel ion concentration at the inlet, and the second electro-deposition adopts high current density, so that the electro-deposition nickel plate with good flatness and glossiness is obtained; the method further has the advantages of being high in preparation efficiency, simple in process and low in requirement for equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of nickel electrodeposition, and relates to a method for nickel electrodeposition, and in particular to a method for nickel electrodeposition and an electrodeposition nickel plate. Background Art

[0002] Electrolytic nickel is a process for extracting metallic nickel from a nickel-containing solution by electrolytic deposition. It is widely used in metallurgy, electroplating, battery materials and other fields. The apparent quality of electrolytic nickel (such as surface finish, crystal density, etc.) directly affects its subsequent processing performance and use value. High-quality electroplated nickel plates should have a uniform crystal structure, a smooth surface, and a low porosity to meet the needs of high-end applications. However, in the actual production process, due to the influence of factors such as electrolyte composition, process parameters and additive selection, the apparent quality of electroplated nickel plates is often difficult to stably control, and is prone to problems such as roughness, nodules, pitting, and pores.

[0003] In order to improve the surface quality of electrolytic nickel, various electrolytic methods have been proposed; for example, pulse electrolytic technology can refine grains and reduce dendrite formation by periodically changing the direction or intensity of current. However, this technology has high requirements on equipment and it is difficult to stably control waveform parameters in large-scale production.

[0004] CN111705334A discloses a method for improving the physical appearance of nickel electroplated in a pure sulfate system. By adding nitrates to the fresh electroplating solution and controlling the pH of the solution, the pores on the surface of the electroplated nickel are effectively reduced. However, this method can easily lead to an accumulation of nitrate content, which adversely affects the surface quality and electrical efficiency of the nickel plate. Consequently, the electroplating tank must be frequently opened and the electroplating solution replaced, significantly increasing the amount of waste liquid to be processed and the workload.

[0005] CN119465298A discloses an electrolytic nickel pore-inhibiting additive composition. During the electrolytic nickel process, the addition of the electrolytic nickel pore-inhibiting additive composition can effectively solve the problems of pores and surface quality. However, during long-term electrolytic deposition, the electrolytic nickel pore-inhibiting additive composition is prone to decomposition and failure, resulting in large fluctuations in the quality of the electrolytic nickel.

[0006] The prior art methods for nickel electrodeposition all have certain drawbacks. For example, the apparent quality of the electrodeposited nickel plates is often difficult to stably control, making it difficult to produce plates of good apparent quality. Furthermore, the production efficiency of the plates is low, the production process is complex, and the equipment requirements are high. Therefore, the development and design of a novel nickel electrodeposition method and plate is of vital importance. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the present invention aims to provide a method for electroplating nickel and an electroplated nickel plate. In the method, a first electroplating solution has a higher nickel ion concentration at the inlet, and a lower current density is used for the first electroplating, thereby obtaining a nickel starting plate with higher surface finish and better crystal density; a second electroplating solution has a lower nickel ion concentration at the inlet, and a higher current density is used for the second electroplating, and electroplating is performed on the nickel starting plate to obtain an electroplated nickel plate with better flatness and gloss; a higher current density is used for deposition during the second electroplating process of the method, thereby improving the preparation efficiency of the electroplated nickel plate; the method also has the advantages of simple process and low equipment requirements.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for electrodepositing nickel, comprising:

[0010] Performing a first electrodeposition in a first electrodeposition solution to obtain a nickel starting electrode sheet;

[0011] The obtained nickel starting plate is used as a cathode, and a second electrodeposition is performed in a second electrodeposition solution to obtain an electrodeposited nickel plate;

[0012] Wherein, the first electrodeposition liquid and the second electrodeposition liquid are both in a flowing in and out state;

[0013] The first electrodeposition solution has a Ni 2 + concentration, higher than the Ni 2 + concentration;

[0014] The current density during the first electrodeposition is lower than the current density during the second electrodeposition.

[0015] In the method for electroplating nickel provided by the present invention, during the first electroplating, the first electroplating solution has a high Ni 2 + concentration (compared to the Ni 2 + concentration) and a lower current density (compared to the current density during the second electrodeposition) was used for electrodeposition, thereby obtaining a nickel starting plate with a higher surface finish and better crystal density, thereby avoiding the formation of pores, surface nodules and edge nodules due to unstable deposition in the early stage of electrodeposition.

[0016] In the method for electroplating nickel provided by the present invention, during the second electroplating, the first electroplating solution has a lower nickel ion concentration at the inlet (compared to the Ni ion concentration at the inlet of the first electroplating solution). 2+ concentration), and adopting a higher current density (compared to the current density during the second electrodeposition) to carry out electrodeposition on the nickel starting plate, an electrodeposited nickel plate with good flatness and glossiness is obtained.

[0017] In the method for electrodepositing nickel provided by the present invention, since a higher current density is used for deposition in the second electrodeposition process, the preparation efficiency of the electrodeposited nickel plate is improved, which is conducive to expanding the production capacity of the electrodeposited nickel plate based on the original equipment.

[0018] The method for electrolytically depositing nickel provided by the present invention has a simple process and low requirements on equipment, thereby reducing the preparation cost of the electrolytically deposited nickel plate and facilitating large-scale promotion and use.

[0019] In the present invention, the first electrodeposition and the second electrodeposition can be carried out in the same deposition container or in different deposition containers; in addition, the first electrodeposition liquid and the second electrodeposition liquid both flow into the deposition container from the inlet of the deposition container, carry out electrodeposition in the deposition container, and flow out of the deposition container from the outlet of the deposition container.

[0020] Preferably, the Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 5 to 20 g / L, for example, 5 g / L, 7 g / L, 9 g / L, 11 g / L, 13 g / L, 15 g / L, 17 g / L, 19 g / L or 20 g / L, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] In the present invention, the Ni 2 + concentration, and the Ni 2 + The difference between the concentrations is: Ni 2 + concentration, higher than the Ni 2 +Concentration value.

[0022] Preferably, the Ni 2 +The concentration is 75 to 85 g / L, for example, it can be 75 g / L, 76 g / L, 77 g / L, 78 g / L, 79 g / L, 80 g / L, 81 g / L, 82 g / L, 83 g / L, 84 g / L or 85 g / L, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0023] Preferably, the Ni 2+The concentration is 65-75 g / L, for example, it can be 65 g / L, 66 g / L, 67 g / L, 68 g / L, 69 g / L, 70 g / L, 71 g / L, 72 g / L, 73 g / L, 74 g / L or 75 g / L, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0024] Preferably, the Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is less than 5 g / L, for example, it can be 0 g / L, 1 g / L, 2 g / L, 3 g / L, 4 g / L or 5 g / L, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] In the present invention, the Ni 2 + concentration, and the Ni 2 + The difference between the concentrations is: Ni 2 + concentration, and the Ni 2 +The absolute value of the difference in concentration.

[0026] Preferably, the Ni 2 +The concentration is 55 to 65 g / L, for example, it can be 55 g / L, 56 g / L, 57 g / L, 58 g / L, 59 g / L, 60 g / L, 61 g / L, 62 g / L, 63 g / L, 64 g / L or 65 g / L, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0027] Preferably, the Ni 2 +The concentration is 55 to 65 g / L, for example, it can be 55 g / L, 56 g / L, 57 g / L, 58 g / L, 59 g / L, 60 g / L, 61 g / L, 62 g / L, 63 g / L, 64 g / L or 65 g / L, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0028] Preferably, the inflow speed of the first electrodeposition liquid at the inlet is lower than the inflow speed of the second electrodeposition liquid at the inlet.

[0029] In the present invention, since the inflow velocity of the second electrodeposition liquid at the inlet is higher (compared to the flow velocity of the first electrodeposition liquid at the inlet), the increase in flow rate can effectively discharge the bubbles attached to the cathode surface during the second electrodeposition, reduce the pores, and at the same time eliminate the surface nodules and edge nodules generated on the nickel plate due to concentration polarization, thereby further improving the quality of the obtained electrodeposited nickel plate.

[0030] Preferably, the first electrodeposition solution contains a wetting agent, and the second electrodeposition solution does not contain a wetting agent.

[0031] In the nickel electrodeposition method provided by the present invention, no wetting agent needs to be added to the second electrodeposition solution. Only by increasing the flow rate of the second electrodeposition solution at the inlet, bubbles attached to the cathode surface can be discharged and concentration polarization can be eliminated, thereby avoiding the problem of brittleness of the electrodeposited nickel plate caused by additives.

[0032] Preferably, the concentration of the wetting agent in the first electrodeposition solution is 20 to 50 mg / L, for example, it can be 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L or 50 mg / L, but is not limited to the listed values. Other values ​​not listed within this numerical range are also applicable.

[0033] Preferably, the wetting agent includes any one of sodium dodecyl sulfonate, octanol, hexanol, propargyl alcohol, polyethylene glycol, alkyl polyoxyethylene ether or potassium perfluorooctane sulfonate, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of sodium dodecyl sulfonate and octanol, a combination of hexanol and propargyl alcohol, a combination of polyethylene glycol and alkyl polyoxyethylene ether, a combination of potassium perfluorooctane sulfonate and sodium dodecyl sulfonate, or a combination of sodium dodecyl sulfonate, polyethylene glycol and alkyl polyoxyethylene ether.

[0034] Preferably, the current density during the first electrodeposition is 140-160 A / m 2 , for example, it can be 140A / m 2 、142A / m 2 、144A / m 2 、146A / m 2 、148A / m 2 、150A / m 2 、152A / m 2 、154A / m 2 、156A / m 2 、158A / m 2 or 160A / m 2 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the temperature of the first electrodeposition solution is 60-70°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0036] Preferably, the first electrodeposition time is 20 to 30 hours, for example, it can be 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours or 30 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the current density during the second electrodeposition is 230-250 A / m 2 , for example, it can be 230A / m 2 , 232A / m 2 , 234A / m 2 , 236A / m 2 , 238A / m 2 , 240A / m 2 , 242A / m 2 , 244A / m 2 , 246A / m 2 , 248A / m 2 or 250A / m 2 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] Preferably, the temperature of the second electrodeposition solution is 60-70°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0039] Preferably, the second electrodeposition time is 120 to 144 hours, for example, it can be 120 hours, 122 hours, 124 hours, 126 hours, 128 hours, 130 hours, 132 hours, 134 hours, 136 hours, 138 hours, 140 hours, 142 hours or 144 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] Preferably, during the first electrodeposition, the seed plate is cathode bagged and used as a cathode, and a nickel starting plate attached to the seed plate is obtained after the first electrodeposition;

[0041] After the first electrodeposition is completed, the obtained nickel starting plate is separated from the seed plate, and then the separated nickel starting plate is used as the cathode in the second electrodeposition.

[0042] In the present invention, the cathode bag refers to a diaphragm bag made of corrosion-resistant fiber fabric (such as nylon, polypropylene or polyester-cotton blend) wrapped around the outside of the cathode; the diaphragm bag wraps and covers the cathode, and its main functions are: 1) blocking particulate impurities such as anode mud suspended in the electrolyte, preventing them from migrating to the cathode surface and attaching to or being wrapped in the cathode deposition layer, resulting in rough coating, pitting, inclusions or holes; 2) optimizing the stability and mass transfer process of the electrodeposition solution near the cathode, and to a certain extent promoting more uniform and dense coating deposition.

[0043] In the present invention, during the first electrodeposition, the seed plate is cathode bagged and used as the cathode. The cathode bagging can achieve physical filtration, ion isolation and flow control, providing multiple guarantees for the quality of the nickel starter sheet during the first electrodeposition, so that the prepared nickel starter sheet has better quality.

[0044] Preferably, the seed plate comprises a titanium plate or a stainless steel plate.

[0045] Preferably, the first electrodeposition solution and the second electrodeposition solution independently contain 60-80 g / L of Na2SO4 and 6-12 g / L of HBO3.

[0046] In the present invention, the first electrodeposition solution and the second electrodeposition solution independently include 60 to 80 g / L of Na2SO4, for example, it can be 60 g / L, 62 g / L, 64 g / L, 66 g / L, 68 g / L, 70 g / L, 72 g / L, 74 g / L, 76 g / L, 78 g / L or 80 g / L, but is not limited to the listed values. Other values ​​not listed within this numerical range are also applicable.

[0047] In the present invention, the first electrodeposition solution and the second electrodeposition solution independently include 6 to 12 g / L of HBO3, for example, 6 g / L, 6.5 g / L, 7 g / L, 7.5 g / L, 8 g / L, 8.5 g / L, 9 g / L, 9.5 g / L, 10 g / L, 10.5 g / L, 11 g / L, 11.5 g / L or 12 g / L, but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0048] Preferably, after the second electrodeposition, the cathode plate obtained is sequentially scalded, pickled, washed with water and dried.

[0049] Preferably, the scalding agent used for scalding includes water with a temperature of 80-90°C, for example, it can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C or 90°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0050] Preferably, the number of scalding times is three times, and the time for each scalding is independently 2 to 5 minutes, for example, it can be 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes or 5 minutes, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] Preferably, the pickling agent used in the pickling includes a sulfuric acid solution with a pH of 1.0 to 1.5, for example, it can be 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] As a preferred technical solution of the method of the present invention, the method includes:

[0053] (1) A titanium plate or a stainless steel plate is used as a cathode after being bagged as a cathode, and a first electrodeposition solution is placed in a deposition container at a temperature of 60 to 70°C at a flow rate of 140 to 160 A / m 2 performing a first electrodeposition at a current density of 1000 nm for 20 to 30 h to obtain a nickel starter sheet attached to the titanium plate or the stainless steel plate, and then separating the obtained nickel starter sheet from the titanium plate or the stainless steel plate to obtain a separated nickel starter sheet;

[0054] (2) The separated nickel starting plate obtained in step (1) is used as the cathode, and the second electrodeposition solution is placed in a deposition container at a temperature of 60 to 70°C at a flow rate of 230 to 250 A / m 2 The second electrodeposition is carried out for 120 to 144 hours at a current density of 1000 nm, and the cathode plate is then scalded three times with water at a temperature of 80 to 90° C. for 2 to 5 minutes respectively, and then acid-washed with a sulfuric acid solution with a pH of 1.0 to 1.5, and then washed with water and dried in sequence to obtain an electrodeposited nickel plate;

[0055] The first electrodeposition liquid and the second electrodeposition liquid are both in a flow-in and flow-out state; the inflow speed of the first electrodeposition liquid at the inlet is lower than the inflow speed of the second electrodeposition liquid at the inlet;

[0056] The first electrodeposition solution has a Ni 2 + concentration is 75-85g / L, the concentration of the wetting agent is 20-50mg / L, the concentration of Na2SO4 is 60-80g / L, the concentration of HBO3 is 6-12g / L, and the Ni at the outlet of the first electrodeposition solution is 20-50mg / L. 2 +Concentration is 55-65g / L;

[0057] The second electrodeposition solution has Ni at the inlet 2+ concentration is 65-75g / L, Na2SO4 concentration is 60-80g / L, HBO3 concentration is 6-12g / L, the Ni 2 +Concentration is 55-65g / L;

[0058] The first electrodeposition solution has a Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 5 to 20 g / L;

[0059] The Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is less than 5 g / L.

[0060] In a second aspect, the present invention provides an electrodeposited nickel plate, which is obtained by the method described in the first aspect.

[0061] The numerical range described in the present invention includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] (1) In the method for electroplating nickel provided by the present invention, during the first electroplating, the first electroplating solution has a high Ni content at the inlet. 2 + concentration (compared to the Ni 2 + concentration) and a lower current density (compared to the current density during the second electrodeposition) was used for electrodeposition, thereby obtaining a nickel starting plate with a higher surface finish and better crystal density, thereby avoiding pores, surface nodules and edge nodules formed due to unstable deposition in the early stage of electrodeposition;

[0064] (2) In the method for nickel electrodeposition provided by the present invention, during the second electrodeposition, the first electrodeposition solution has a lower Ni content at the inlet. 2 + concentration (compared to the Ni 2 + concentration), and a higher current density (compared to the current density during the second electrodeposition) was used to perform electrodeposition on the nickel starting plate, thereby obtaining an electrodeposited nickel plate with good flatness and glossiness;

[0065] (3) In the method for electrodepositing nickel provided by the present invention, since a higher current density is used for deposition in the second electrodeposition process, the preparation efficiency of the electrodeposited nickel plate is improved, which is conducive to expanding the production capacity of the electrodeposited nickel plate on the basis of the original equipment;

[0066] (4) The method for electroplating nickel provided by the present invention has a simple process and low requirements for equipment, thereby reducing the preparation cost of the electroplated nickel plate and facilitating large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is an appearance diagram of the electrodeposited nickel plate prepared by the electrodeposited nickel method provided in Example 1. DETAILED DESCRIPTION

[0068] It should be understood that, in the description of the present invention, the terms "first," "second," etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of such features.

[0069] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0070] Example 1

[0071] This embodiment provides a method for electrodepositing nickel, the method comprising:

[0072] (1) A titanium plate or a stainless steel plate is used as a cathode after being bagged as a cathode. In the first electroplating solution at a temperature of 65°C in the deposition container, a current of 150A / m is applied. 2 A first electrodeposition is performed for 25 hours at a current density of 1000 nm to obtain a nickel starter sheet attached to the titanium plate or the stainless steel plate, and then the obtained nickel starter sheet is separated from the titanium plate or the stainless steel plate to obtain a separated nickel starter sheet;

[0073] (2) The separated nickel starting plate obtained in step (1) was used as the cathode, and the second electrodeposition solution at a temperature of 65°C in the deposition container was heated at 240A / m 2 A second electrodeposition was performed for 132 hours at a current density of 1000 nm, and the cathode plate was then scalded three times with water at a temperature of 85° C. for 3.5 minutes each, and then acid-washed with a sulfuric acid solution with a pH of 1.2, and then washed with water and dried in sequence to obtain an electrodeposited nickel plate.

[0074] The first electrodeposition liquid and the second electrodeposition liquid are both in a flow-in and flow-out state; the inflow speed of the first electrodeposition liquid at the inlet is lower than the inflow speed of the second electrodeposition liquid at the inlet;

[0075] The first electrodeposition solution has a Ni 2+ concentration of 80g / L (Ni provided by nickel sulfate 2 +), the concentration of sodium lauryl sulfate is 35mg / L, the concentration of Na2SO4 is 70g / L, the concentration of HBO3 is 9g / L, and the Ni content of the first electrodeposition solution at the outlet is 0.0447 ... 2 +Concentration is 60g / L;

[0076] The second electrodeposition solution has Ni at the inlet 2 + concentration of 70g / L (Ni provided by nickel sulfate 2 +), the concentration of Na2SO4 is 70g / L, the concentration of HBO3 is 9g / L, and the Ni 2 +Concentration is 60g / L;

[0077] The first electrodeposition solution has a Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 10 g / L;

[0078] The Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 0 g / L.

[0079] Example 2

[0080] This embodiment provides a method for electrodepositing nickel, the method comprising:

[0081] (1) A titanium plate or a stainless steel plate is used as a cathode after being bagged as a cathode. In the first electroplating solution at a temperature of 60°C in the deposition container, a current of 160A / m is applied. 2 A first electrodeposition is performed for 20 hours at a current density of 1000 nm to obtain a nickel starter sheet attached to the titanium plate or the stainless steel plate, and then the obtained nickel starter sheet is separated from the titanium plate or the stainless steel plate to obtain a separated nickel starter sheet;

[0082] (2) The separated nickel starting plate obtained in step (1) was used as the cathode, and the second electrodeposition solution at a temperature of 60°C in the deposition container was used to deposit the nickel starting plate at a current of 250A / m 2 The second electrodeposition was carried out for 120 hours at a current density of 1000 nm, and the cathode plate was scalded three times with water at a temperature of 90° C. for 2 minutes each, and then acid-washed with a sulfuric acid solution with a pH of 1.0, and then washed with water and dried in sequence to obtain an electrodeposited nickel plate.

[0083] The first electrodeposition liquid and the second electrodeposition liquid are both in a flow-in and flow-out state; the inflow speed of the first electrodeposition liquid at the inlet is lower than the inflow speed of the second electrodeposition liquid at the inlet;

[0084] The first electrodeposition solution has a Ni 2 + concentration of 75g / L (Ni provided by nickel sulfate 2 +), the concentration of sodium lauryl sulfate is 50mg / L, the concentration of Na2SO4 is 60g / L, the concentration of HBO3 is 6g / L, and the Ni content of the first electrodeposition solution at the outlet is 0.0447777. 2 +Concentration is 55g / L;

[0085] The second electrodeposition solution has Ni at the inlet 2 + concentration of 70g / L (Ni provided by nickel sulfate 2 +), the concentration of Na2SO4 is 60g / L, the concentration of HBO3 is 6g / L, and the Ni 2 +Concentration is 56g / L;

[0086] The first electrodeposition solution has a Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 5 g / L;

[0087] The Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 1 g / L.

[0088] Example 3

[0089] This embodiment provides a method for electrodepositing nickel, the method comprising:

[0090] (1) A titanium plate or a stainless steel plate is used as a cathode after being bagged as a cathode. In the first electroplating solution at a temperature of 70°C in the deposition container, a current of 140A / m is applied. 2 A first electrodeposition is performed for 30 hours at a current density of 1000 nm to obtain a nickel starter sheet attached to the titanium plate or the stainless steel plate, and then the obtained nickel starter sheet is separated from the titanium plate or the stainless steel plate to obtain a separated nickel starter sheet;

[0091] (2) The separated nickel starting plate obtained in step (1) was used as the cathode, and the second electrodeposition solution at a temperature of 70°C in the deposition container was heated at 230A / m 2 The second electrodeposition was carried out for 144 hours at a current density of 1.5, and the cathode plate was scalded three times with water at a temperature of 80° C. for 5 minutes each, and then acid-washed with a sulfuric acid solution with a pH of 1.5, and then washed with water and dried in sequence to obtain an electrodeposited nickel plate.

[0092] The first electrodeposition liquid and the second electrodeposition liquid are both in a flow-in and flow-out state; the inflow speed of the first electrodeposition liquid at the inlet is lower than the inflow speed of the second electrodeposition liquid at the inlet;

[0093] The first electrodeposition solution has a Ni 2 + concentration of 85g / L (Ni provided by nickel sulfate 2 +), the concentration of sodium lauryl sulfate is 20 mg / L, the concentration of Na2SO4 is 80 g / L, the concentration of HBO3 is 12 g / L, and the Ni content of the first electrodeposition solution at the outlet is 0.0447 W / L. 2 +Concentration is 65g / L;

[0094] The second electrodeposition solution has Ni at the inlet 2 + concentration of 75g / L (Ni provided by nickel sulfate 2 +), the concentration of Na2SO4 is 80g / L, the concentration of HBO3 is 12g / L, and the Ni 2 +Concentration is 62g / L;

[0095] The first electrodeposition solution has a Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 10 g / L;

[0096] The Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 3 g / L.

[0097] Example 4

[0098] This embodiment provides a method for electrodepositing nickel, which is the same as that of Example 1 except that sodium dodecyl sulfate is omitted from the first electrodeposition solution.

[0099] Example 5

[0100] This embodiment provides a method for nickel electrodeposition, which is the same as that of Example 1 except that the second electrodeposition solution further contains sodium dodecyl sulfate with a concentration of 35 mg / L at the inlet.

[0101] Example 6

[0102] This embodiment provides a method for electroplating nickel, except that in step (1) the electrodeposition temperature is 120A / m 2 Except for the first electrodeposition being carried out at a current density of , the rest are the same as in Example 1.

[0103] Example 7

[0104] This embodiment provides a method for electroplating nickel, except that in step (1) the electrodeposition temperature is 180A / m 2 Except for the first electrodeposition being carried out at a current density of , the rest are the same as in Example 1.

[0105] Example 8

[0106] This embodiment provides a method for electroplating nickel, except that in step (2) the current is 200A / m 2 Except for the second electrodeposition being carried out at a current density of , the rest are the same as in Example 1.

[0107] Example 9

[0108] This embodiment provides a method for electroplating nickel, except that in step (2) the current is 300A / m 2 Except for the second electrodeposition being carried out at a current density of , the rest are the same as in Example 1.

[0109] Comparative Example 1

[0110] This comparative example provides a method for nickel electrodeposition, except that the first electrodeposition solution has a Ni 2 + concentration is 70g / L, the Ni 2 +Concentration is 60g / L;

[0111] The second electrodeposition solution has Ni at the inlet 2 + concentration is 70g / L, the Ni 2 +Concentration is 60g / L;

[0112] The first electrodeposition solution has a Ni 2 + concentration, and the Ni 2 +Except that the difference between the concentrations is 0 g / L, the rest are the same as in Example 1.

[0113] Comparative Example 2

[0114] This comparative example provides a method for nickel electrodeposition, except that the first electrodeposition solution has a Ni 2 + concentration is 80g / L, the Ni 2 +Concentration is 60g / L;

[0115] The second electrodeposition solution has Ni at the inlet 2 + concentration is 80g / L, the Ni 2 +Concentration is 60g / L;

[0116] The first electrodeposition solution has a Ni 2 + concentration, and the Ni2 +Except that the difference between the concentrations is 0 g / L, the rest are the same as in Example 1.

[0117] Comparative Example 3

[0118] This comparative example provides a method for nickel electrodeposition, except that the first electrodeposition solution has a Ni 2 + concentration is 65g / L, the Ni 2 +Concentration is 60g / L;

[0119] The second electrodeposition solution has Ni at the inlet 2 + concentration is 70g / L, the Ni 2 +Concentration is 60g / L;

[0120] The first electrodeposition solution has a Ni 2 + concentration, less than the Ni 2 + concentration, the rest are the same as in Example 1.

[0121] Comparative Example 4

[0122] This comparative example provides a method for electroplating nickel, except that in step (1) the electrodeposition temperature is 260A / m 2 Except for the first electrodeposition being carried out at a current density of , the rest are the same as in Example 1.

[0123] Comparative Example 5

[0124] This comparative example provides a method for electroplating nickel, except that in step (2) the electrodeposition temperature is 120A / m 2 Except for the second electrodeposition being carried out at a current density of , the rest are the same as in Example 1.

[0125] In the same equipment, the electrodeposited nickel plate was prepared by the method of electrodepositing nickel provided in the above embodiment and comparative example (wherein the appearance of the electrodeposited nickel plate prepared by the method provided in Example 1 is shown in FIG. Figure 1 All the electrodeposited nickel plates obtained by each method were observed separately, and the ratio of the number of qualified electrodeposited nickel plates obtained by each method (the electrodeposited nickel plates that are flat, have a porosity of less than 5% and cannot be observed with the naked eye to have surface nodules and edge nodules are determined to be qualified electrodeposited nickel plates) to the total electrodeposited nickel plates (i.e., the qualified rate) is shown in Table 1; wherein, the definition of surface flatness is: no obvious protrusions or pits can be observed on the surface of the electrodeposited nickel plate by the naked eye.

[0126] Table 1

[0127] Pass rate (%) Example 1 75 Example 2 73 Example 3 78 Example 4 70 Example 5 69 Example 6 68 Example 7 69 Example 8 71 Example 9 70 Comparative Example 1 71 Comparative Example 2 67 Comparative Example 3 62 Comparative Example 4 57 Comparative Example 5 69

[0128] In the same equipment, 10 electrodeposited nickel plates were prepared using the methods provided in Example 1 and Comparative Examples 3 and 4, respectively. The average thickness of the 10 electrodeposited nickel plates obtained using each method was calculated, and the calculation results are shown in Table 2.

[0129] Table 2

[0130]

[0131] From Table 1 and Table 2, we can get:

[0132] (1) When the electrodeposited nickel plates are prepared by the methods provided in Examples 1 to 3 of the present invention, the preparation efficiency is high, and the surface quality of the prepared electrodeposited nickel plates is excellent, with a high pass rate;

[0133] (2) By comparing Example 1 with Examples 4 and 5, it can be seen that in the present invention, a wetting agent is added to the first electrodeposition solution, which improves the quality of the prepared nickel starting plate, and the second electrodeposition is performed on the nickel starting plate with higher quality, thereby ensuring the quality of the electrodeposited nickel plate finally prepared; in the method for electrodepositing nickel provided by the present invention, the second electrodeposition solution does not need to contain a wetting agent, and only by increasing the flow rate of the second electrodeposition solution at the inlet, the bubbles attached to the cathode surface can be discharged and the concentration polarization can be eliminated, thereby avoiding the problem of brittleness of the electrodeposited nickel plate caused by the additive;

[0134] (3) By comparing Example 1 with Examples 6 and 7, it can be seen that in the present invention, the current density during the first electrodeposition affects the qualified rate of the electrodeposited nickel plate; when the current density during the first electrodeposition is 140-160 A / m 2 When the current density during the first electrodeposition is within this range, the high metal ion concentration during the first precipitant can ensure sufficient ion supply on the electrode surface, and the low current density can effectively reduce concentration polarization, so that nickel ions are uniformly reduced and deposited, and dendrite growth and hole defects are avoided, thereby forming a dense and uniform electrodeposited nickel plate. At this time, the deposition rate is moderate, which not only reduces the hydrogen evolution side reaction and rough surface caused by excessively high current density, but also avoids the decrease in deposition efficiency at too low current density.

[0135] (4) By comparing Example 1 with Examples 8 and 9, it can be seen that in the present invention, the current density during the second electrodeposition affects the qualified rate of the electrodeposited nickel plate; when the current density during the second electrodeposition is 230-250 A / m 2When the current density of the second electrodeposition is within this range, the electrodeposited nickel plate has a high pass rate. This is because when the current density of the second electrodeposition is within this range, the low metal ion concentration reduces the ion accumulation in the solution, and the high current density can enhance the ion migration rate, overcome the mass transfer limitation under low concentration, and promote the rapid and uniform reduction of nickel ions on the electrode surface; at the same time, the high current density can inhibit the excessive growth of dendrites, and cooperate with the low concentration environment to reduce the probability of hydrogen evolution side reaction, forming a dense and flat nickel plate structure, which not only ensures the deposition efficiency, but also improves the product pass rate by optimizing the crystallization process; in addition, the high current density can also accelerate the deposition speed, thereby improving the preparation efficiency of the electrodeposited nickel plate;

[0136] (5) By comparing Example 1 with Comparative Examples 1 to 5, it can be seen that in the method for nickel electrodeposition provided by the present invention, during the first electrodeposition, the first electrodeposition solution has a higher Ni content at the inlet. 2 + concentration (compared to the Ni 2 + concentration) and a lower current density (compared to the current density during the second electrodeposition) was used for electrodeposition, thereby obtaining a nickel starting plate with a higher surface finish and better crystal density, thereby avoiding pores, surface nodules and edge nodules formed due to unstable deposition in the early stage of electrodeposition;

[0137] In the method for nickel electrodeposition provided by the present invention, during the second electrodeposition, the first electrodeposition solution has a lower Ni content at the inlet. 2 + concentration (compared to the Ni 2 + concentration), and a higher current density (compared to the current density during the second electrodeposition) was used to perform electrodeposition on the nickel starting plate, thereby obtaining an electrodeposited nickel plate with good flatness and glossiness;

[0138] The method for electrodepositing nickel provided by the present invention has a simple process and low requirements on equipment, thereby reducing the preparation cost of the electrodeposited nickel plate and facilitating large-scale promotion and use.

[0139] (6) By comparing Example 1 with Comparative Examples 4 and 5, it can be seen that in the method for electroplating nickel provided by the present invention, Comparative Example 4 adopts a higher current density from beginning to end, and the average thickness of the prepared electroplated nickel plate is slightly higher than that of Example 1, but the qualified rate is much lower than that of Example 1; Comparative Example 5 adopts a lower current density from beginning to end, not only the average thickness of the prepared electroplated nickel plate is much lower than that of Example 1, but the qualified rate is also much lower than that of Example 1; it can be seen that in the present invention, a lower current density is used for deposition in the first electroplating process and a higher current density is used for deposition in the second electroplating process, which not only improves the preparation efficiency of the electroplated nickel plate, but also helps to expand the production capacity of the electroplated nickel plate based on the original equipment.

[0140] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for electrodepositing nickel, characterized in that: The method comprises: Performing a first electrodeposition in a first electrodeposition solution to obtain a nickel starting electrode sheet; The obtained nickel starting plate is used as a cathode, and a second electrodeposition is performed in a second electrodeposition solution to obtain an electrodeposited nickel plate; Wherein, the first electrodeposition liquid and the second electrodeposition liquid are both in a flowing in and out state; The first electrodeposition solution has a Ni 2 + concentration, higher than the Ni 2 + concentration; The current density during the first electrodeposition is lower than the current density during the second electrodeposition.

2. The method according to claim 1, characterized in that The first electrodeposition solution has a Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 5 to 20 g / L; Preferably, the Ni 2 +Concentration is 75-85g / L; Preferably, the Ni 2 +Concentration is 65~75g / L.

3. The method according to claim 1, characterized in that The Ni 2 + concentration, and the Ni 2 +The difference between concentrations is less than 5 g / L; Preferably, the Ni 2 +Concentration is 55-65g / L; Preferably, the Ni 2 +Concentration is 55-65g / L.

4. The method according to claim 1, wherein The inflow speed of the first electrodeposition liquid at the inlet is lower than the inflow speed of the second electrodeposition liquid at the inlet.

5. The method according to claim 1, wherein The first electrodeposition solution contains a wetting agent, and the second electrodeposition solution does not contain a wetting agent; Preferably, the concentration of the wetting agent in the first electrodeposition solution is 20-50 mg / L.

6. The method according to claim 1, characterized in that The current density during the first electrodeposition is 140 to 160 A / m 2 ; Preferably, the temperature of the first electrodeposition solution is 60-70°C; Preferably, the first electrodeposition time is 20 to 30 hours.

7. The method according to claim 1, characterized in that The current density during the second electrodeposition is 230-250 A / m 2 ; Preferably, the temperature of the second electrodeposition solution is 60-70°C; Preferably, the second electrodeposition time is 120 to 144 hours.

8. The method according to claim 1, characterized in that During the first electrodeposition, the seed plate is cathode bagged and used as a cathode, and a nickel starting plate attached to the seed plate is obtained after the first electrodeposition; After the first electrodeposition is completed, the obtained nickel starting plate is separated from the seed plate, and then the separated nickel starting plate is used as the cathode in the second electrodeposition.

9. The method according to claim 1, characterized in that The method comprises: (1) A titanium plate or a stainless steel plate is used as a cathode after being cathode-bagged, and a first electrodeposition solution at 60-70°C is used to deposit the plate at 140-160 A / m 2 Performing a first electrodeposition at a current density of 1000 nm for 20 to 30 h to obtain a nickel starter sheet attached to the titanium plate or stainless steel plate, and then separating the obtained nickel starter sheet from the titanium plate or stainless steel plate to obtain a separated nickel starter sheet; (2) The separated nickel starting plate obtained in step (1) is used as the cathode, and the second electrodeposition solution is heated at 60-70°C and 230-250A / m 2 The second electrodeposition is carried out for 120 to 144 hours at a current density of 1000 nm, and the cathode plate is then scalded three times with water at a temperature of 80 to 90° C. for 2 to 5 minutes respectively, and then acid-washed with a sulfuric acid solution with a pH of 1.0 to 1.5, and then washed with water and dried in sequence to obtain an electrodeposited nickel plate; The first electrodeposition liquid and the second electrodeposition liquid are both in a flow-in and flow-out state; the inflow speed of the first electrodeposition liquid at the inlet is lower than the inflow speed of the second electrodeposition liquid at the inlet; The first electrodeposition solution has a Ni 2 + concentration is 75-85g / L, the concentration of the wetting agent is 20-50mg / L, the concentration of Na2SO4 is 60-80g / L, the concentration of HBO3 is 6-12g / L, and the Ni in the outlet of the first electrodeposition solution is 100g / L. 2 +Concentration is 55-65g / L; The second electrodeposition solution has a Ni 2 + concentration is 65-75g / L, Na2SO4 concentration is 60-80g / L, HBO3 concentration is 6-12g / L, the Ni 2 +Concentration is 55-65g / L; The first electrodeposition solution has a Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is 5 to 20 g / L; The Ni 2 + concentration, and the Ni 2 +The difference between the concentrations is less than 5 g / L.

10. An electrodeposited nickel plate, characterized in that: The electrodeposited nickel plate is obtained by the method according to any one of claims 1 to 9.

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