Battery case barrel nickel plating solution and barrel plating method applying nickel plating solution

Abstract

The invention discloses a barrel nickel plating solution for a battery case and a barrel plating method applying the nickel plating solution. The barrel nickel plating solution for the battery case comprises the following components: nickel sulfate, nickel chloride, boric acid, sodium dodecyl sulfate, ammonium sulfate, sodium vinylsulfonate, pyridinium propane sulphogroup inner salt and carboxyethyl isothiourea betaine. The barrel plating method using the nickel plating solution comprises the following steps of pretreatment, heating, battery steel shell placement and barrel plating. Compared with the prior art, the method has the advantage that the prepared coating is good in corrosion resistance and consistency.

Description

Technical Field

[0001] The invention relates to the technical field of electroplating, and in particular to a battery shell roll-plating nickel plating solution and a roll-plating method using the nickel plating solution. Background Art

[0002] As a key component of the battery, the shell material of lithium-ion batteries combines structural and functional properties, and has a significant impact on the electrochemical performance and safety performance of lithium-ion batteries. On the one hand, power batteries will be subjected to vibration, impact, high and low temperature and humidity during use, and the electrodes and electrolytes are filled inside the steel shell, which requires the battery steel shell to have good mechanical properties and corrosion resistance.

[0003] The current method to improve the corrosion resistance of steel shells for lithium-ion batteries is mainly through nickel electroplating, generally using roller plating. However, during the roller plating process, the steel shell is in different positions in the roller, and the current is unevenly distributed in different parts of the steel shell, resulting in uneven coating thickness and poor uniformity of the battery shell.

[0004] The deep hole nickel plating additives used in the prior art are complex in types and cannot ensure the consistency of the inner and outer coatings of the battery steel shell. This is mainly because the difference in current density inside and outside leads to a large polarization gap. While the performance of the outer layer meets the requirements, the thickness of the inner layer is insufficient, and the corrosion resistance is reduced.

[0005] Therefore, it is of great significance to develop a battery shell nickel plating solution with good deep plating performance and good corrosion resistance. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide a battery shell nickel plating solution with good corrosion resistance in view of the above technical status.

[0007] The second technical problem to be solved by the present invention is to provide a roller plating method for a battery shell using the nickel plating solution with good corrosion resistance in view of the above-mentioned technical status quo.

[0008] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a battery shell roller nickel plating solution, characterized in that it includes the following components: nickel sulfate, nickel chloride, boric acid, sodium dodecyl sulfonate and ammonium sulfate, sodium vinyl sulfonate, pyridinium propane sulfonate and carboxyethyl isothiourea betaine.

[0009] Preferably, the component concentrations of the battery shell nickel plating solution are: nickel sulfate 240-350 g / L, nickel chloride 20-60 g / L, boric acid 20-60 g / L, sodium dodecyl sulfate 0.5-1.5 g / L, ammonium sulfate 5-30 g / L, sodium vinyl sulfonate 0.005-0.05 g / L, pyridinium propane sulfonate 0.01-0.05 g / L and carboxyethyl isothiourea betaine 0.001-0.01 g / L.

[0010] Preferably, the battery shell nickel plating solution includes a conventional base solution, a deep plating agent and a low-zone moving agent.

[0011] Preferably, the deep plating agent and low-zone moving agent include the following components: 0.005-0.05 g / L sodium vinyl sulfonate, 0.01-0.05 g / L pyridinium propane sulfonate, and 0.001-0.01 g / L carboxyethyl isothiourea betaine.

[0012] Preferably, the conventional base liquid comprises the following components: nickel sulfate, nickel chloride, boric acid, sodium dodecyl sulfate and ammonium sulfate.

[0013] Preferably, the concentration of the conventional base solution nickel sulfate is 250-350 g / L.

[0014] The technical solution adopted by the present invention to solve the above second technical problem is: a barrel plating method using the above-mentioned battery shell barrel nickel plating solution, characterized in that it includes the following steps:

[0015] S1. Pretreatment: degreasing and activation of battery steel shell;

[0016] S2, heating: controlling the temperature of the battery shell nickel plating solution in the barrel plating machine to 30-60°C;

[0017] S3, placing the battery steel shell: placing the battery steel shell obtained in step S1 into the drum of the drum plating machine, and the amount of the battery steel shell placed is 1 / 3 to 1 / 2 of the drum volume;

[0018] S4, roll plating: start the roll plating machine and carry out roll plating.

[0019] Preferably, the step S1 is: degreasing and activating the cleaned battery steel shell.

[0020] Preferably, the deoiling agent for the deoiling treatment in step S1 is a mixture of one or more of sodium hydroxide, sodium metaphosphate and fatty acid diethanolamide, and the activating agent for the activation treatment is 5-10wt% dilute sulfuric acid for pickling, and the pickling time is 1-2 minutes.

[0021] Preferably, the current density of the roller plating in step S4 is 0.02-0.05A / dm 2The roller plating time is 60-120min, and the roller speed of the roller plating machine is 5-15r / min.

[0022] Compared with the prior art, the advantages of the present invention are: by compounding the nickel plating solution for battery shell roll plating, the corrosion resistance of the resulting coating is improved, and the corrosion resistance of the inner coating is improved; in addition, the consistency of the resulting outer coating is improved, and the tolerance to high current density in roll plating is higher, and it is not easy to cause burning in the high current density area. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Photos of the nickel-plated inner wall of the battery shell of Example 1 and Comparative Example 1;

[0024] Figure 2 Surface morphology of the nickel coating of Example 2 and Comparative Example 2;

[0025] Figure 3 3 and comparative example 3 are polarization curves. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings.

[0027] Example 1

[0028] A blind hole battery steel shell barrel nickel plating solution and a barrel plating method using the nickel plating solution, specifically comprising the following steps:

[0029] Preparation of battery shell nickel plating solution: 240g nickel sulfate, 40g nickel chloride, 30g boric acid, 10g ammonium sulfate, 0.5g sodium dodecyl sulfate were added to 1L deionized water to prepare a conventional base solution; then, a deep plating agent and a low-zone moving agent were added to the conventional base solution in sequence, and the main components of the deep plating agent and the low-zone moving agent were: 0.01g sodium vinyl sulfonate, 0.025g pyridinium propane sulfonate and 0.005g carboxyethyl isothiourea betaine. After that, magnetic stirring was performed for 60min until the solution was clear, and the pH value was adjusted to 4.2 using sodium hydroxide and sulfuric acid solution; the battery shell nickel plating solution was prepared, and the content of each component is shown in Table 1.

[0030] The barrel plating method using the battery shell nickel plating solution with good corrosion resistance comprises the following steps:

[0031] S1. The battery steel shell matrix material is pre-treated by washing → primary degreasing → water washing → secondary degreasing → water washing → activation → washing, etc. The degreasing agent is a mixed solution of sodium hydroxide, sodium metaphosphate and fatty acid diethanolamide, and the activation is: pickling in 5wt% dilute sulfuric acid solution as an activator for 1-2 minutes to remove the surface rust layer until a uniform metallic luster matrix is ​​exposed;

[0032] S2, put the activated battery steel shell into the drum of the roller plating machine, and the amount of battery steel shell put in accounts for 1 / 3 of the volume of the drum;

[0033] S3, roll plating for 45 min at a bath temperature of 45°C and a current density of 0.025 A / dm 2 , the drum speed is 7r / min; a bright nickel-plated layer appears on the inner wall of the stainless steel base material.

[0034] Example 2

[0035] A blind hole battery steel shell barrel nickel plating solution and a barrel plating method using the nickel plating solution, specifically comprising the following steps:

[0036] Preparation of battery shell nickel plating solution: 260g nickel sulfate, 45g nickel chloride, 35g boric acid, 15g ammonium sulfate, 1g sodium dodecyl sulfate were added to 1L deionized water to prepare a conventional base solution; then, a deep plating agent and a low-zone moving agent were added to the conventional base solution in sequence, and the main components of the deep plating agent and the low-zone moving agent were: 0.02g sodium vinyl sulfonate, 0.05g pyridinium propane sulfonate and 0.0075g carboxyethyl isothiourea betaine. Magnetic stirring was performed for 60min until the solution was clear, and the pH value of the plating solution was adjusted to 4.2 using sodium hydroxide and sulfuric acid solution; the battery shell nickel plating solution was prepared, and the contents of each component are shown in Table 1.

[0037] The barrel plating method using the battery shell nickel plating solution with good corrosion resistance comprises the following steps:

[0038] S1. The battery steel shell matrix material is pre-treated by washing → primary degreasing → water washing → secondary degreasing → water washing → activation → washing, etc. The degreasing agent is a mixed solution of sodium hydroxide, sodium metaphosphate and fatty acid diethanolamide, and the activation is: pickling in 5wt% dilute sulfuric acid solution as an activator for 1-2 minutes to remove the surface rust layer until a uniform metallic luster matrix is ​​exposed;

[0039] S2, put the activated battery steel shell into the drum of the roller plating machine, and the amount of battery steel shell put in accounts for 1 / 3 of the volume of the drum;

[0040] S3, roll plating for 45 min at a bath temperature of 45°C and a current density of 0.03 A / dm 2 , the drum speed is 10r / min; a bright nickel-plated layer appears on the inner wall of the stainless steel base material.

[0041] Example 3

[0042] A blind hole battery steel shell barrel nickel plating solution and a barrel plating method using the nickel plating solution, specifically comprising the following steps:

[0043] Preparation of battery shell nickel plating solution: 280g nickel sulfate, 50g nickel chloride, 40g boric acid, 20g ammonium sulfate, 1.5g sodium dodecyl sulfonate were added to 1L deionized water to prepare a conventional base solution; then, a deep plating agent and a low-zone moving agent were added to the conventional base solution in sequence, and the main components were: 0.02g sodium vinyl sulfonate, 0.1g pyridinium propane sulfonate and 0.01g carboxyethyl isothiourea betaine. The solution was stirred magnetically for 60min until it was clear, and the pH value of the plating solution was adjusted to 4.2 using sodium hydroxide and sulfuric acid solution; the battery shell nickel plating solution was prepared, and the content of each component is shown in Table 1. .

[0044] The barrel plating method using the battery shell nickel plating solution with good corrosion resistance comprises the following steps:

[0045] S1. The battery steel shell matrix material is pre-treated by washing → primary degreasing → water washing → secondary degreasing → water washing → activation → washing, etc. The degreasing agent is a mixed solution of sodium hydroxide, sodium metaphosphate and fatty acid diethanolamide, and the activation is: pickling in 5wt% dilute sulfuric acid solution as an activator for 1-2 minutes to remove the surface rust layer until a uniform metallic luster matrix is ​​exposed;

[0046] S2, put the activated battery steel shell into the drum of the roller plating machine, and the amount of battery steel shell put in accounts for 1 / 3 of the volume of the drum;

[0047] S3, roll plating for 45 min at a bath temperature of 45°C and a current density of 0.035 A / dm 2 , the drum speed is 15r / min; a bright nickel-plated layer appears on the inner wall of the stainless steel base material.

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 1 is that the electroplating solution in the comparative example only uses the conventional base solution in Example 1.

[0050] The battery shell obtained in Example 1 was cut longitudinally to observe the nickel plating on the inner wall of the tube, and the nickel plating solution of the battery shell prepared in Example 1 was analyzed by taking pictures; Figure 1 The left side is the inner wall of the battery shell of Comparative Example 1, and the right side is the battery shell prepared in Example 1; it can be seen that the inner wall plating end of Comparative Example 1 has blackening due to missing plating, and is rusted and not bright; the inner wall of Example 1 is completely plated with a nickel layer, and the nickel layer is bright white.

[0051] Comparative Example 2

[0052] The difference between this comparative example and Example 2 is that the electroplating solution in the comparative example only uses the conventional base solution in Example 2.

[0053] like Figure 2As shown, it is the surface morphology of the nickel coating prepared in Example 2 and Comparative Example 2, wherein (a) is the coating obtained in Comparative Example 2, and (b) is the coating obtained in Example 2. It can be seen that the coating prepared in Comparative Example 2 is thinner, the particles are more dispersed, and a large number of scratches on the bottom substrate can be observed; while the coating obtained by rolling the nickel plating solution for the battery shell using Example 2 has a dense structure and uniform grains.

[0054] Comparative Example 3

[0055] The difference between this comparative example and Example 3 is that the electroplating solution in the comparative example only uses the conventional base solution in Example 3.

[0056] like Figure 3 As shown, it is a polarization curve diagram of the coating prepared in Example 3 and Comparative Example 3. It can be seen that the corrosion resistance of the coating prepared in Example 3 and Comparative Example 3 is poor, while the corrosion resistance of the coating prepared in Example 3 is good, showing a higher corrosion potential and a lower corrosion current.

[0057] Table 1 Contents of components in the nickel plating solution for battery shells of Examples 1-3

[0058]

[0059]

Claims

1. A battery shell nickel plating solution, Features: The invention comprises the following components: nickel sulfate, nickel chloride, boric acid, sodium dodecyl sulfonate and ammonium sulfate, sodium vinyl sulfonate, pyridinium propane sulfonate and carboxyethyl isothiourea betaine.

2. The battery shell nickel plating solution according to claim 1, Features: The component concentrations of the battery shell roller nickel plating solution are: nickel sulfate 240-350g / L, nickel chloride 20-60g / L, boric acid 20-60g / L, sodium dodecyl sulfate 0.5-1.5g / L, ammonium sulfate 5-30g / L, sodium vinyl sulfonate 0.005-0.05g / L, pyridinium propane sulfonate 0.01-0.05g / L and carboxyethyl isothiourea betaine 0.001-0.01g / L.

3. The battery shell nickel plating solution according to claim 1, Features: The battery shell nickel rolling plating solution comprises a conventional base solution, a deep plating agent and a low-zone moving agent.

4. The battery shell nickel plating solution according to claim 3, Features: The deep plating agent and low-zone moving agent include the following components: 0.005-0.05 g / L of sodium vinyl sulfonate, 0.01-0.05 g / L of pyridinium propane sulfonate, and 0.001-0.01 g / L of carboxyethyl isothiourea betaine.

5. The battery shell nickel plating solution according to claim 3, Features: The conventional base liquid includes the following components: nickel sulfate, nickel chloride, boric acid, sodium dodecyl sulfate and ammonium sulfate.

6. The battery shell nickel plating solution according to claim 5, Features: The concentration of the conventional base solution nickel sulfate is 250-350 g / L.

7. A barrel plating method using the battery shell nickel barrel plating solution according to any one of claims 1 to 6, Features: The following steps are involved: S1. Pretreatment: degreasing and activation of battery steel shell; S2, heating: controlling the temperature of the battery shell nickel plating solution in the barrel plating machine to 30-60°C; S3, placing the battery steel shell: placing the battery steel shell obtained in step S1 into the drum of the drum plating machine, and the amount of the battery steel shell placed is 1 / 3 to 1 / 2 of the drum volume; S4, roll plating: start the roll plating machine and carry out roll plating.

8. The barrel plating method according to claim 7, Features: The step S1 is: degreasing and activating the cleaned battery steel shell.

9. The barrel plating method according to claim 8, Features: In the step S1, the deoiling agent for the deoiling treatment is a mixture of one or more of sodium hydroxide, sodium metaphosphate and fatty acid diethanolamide, and the activating agent for the activation treatment is 5-10wt% dilute sulfuric acid for pickling, and the pickling time is 1-2 minutes.

10. The barrel plating method according to claim 7, Features: The current density of the roller plating in step S4 is 0.02-0.05A / dm 2 The roller plating time is 60-120min, and the roller speed of the roller plating machine is 5-15r / min.

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