Anti-oxidation liquid and anti-oxidation treatment method for lithium battery copper foil

Abstract

The invention relates to the technical field of copper surface treatment, and provides an anti-oxidation liquid, the anti-oxidation liquid comprises molybdate, phosphate, hydrogen peroxide, a pH value regulator and water, the anti-oxidation liquid is alkaline, the concentration of molybdate is 5-15 g / L, the concentration of phosphate is 5-20 g / L, the concentration of hydrogen peroxide is 10-30 mL / L, and the pH value of the solution is 10. The prepared anti-oxidation liquid has the advantages of being simple in component and stable in system, and meanwhile the high-temperature oxidation resistance and the corrosion resistance of the copper foil treated through the anti-oxidation liquid are both improved; in addition, the anti-oxidation liquid does not contain toxic substances, a large amount of wastewater with complex components cannot be generated when the anti-oxidation liquid is adopted for anti-oxidation treatment of the copper foil, and the pressure and the treatment cost of the enterprise environmental protection department are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of copper surface treatment, and in particular to an anti-oxidation liquid and an anti-oxidation treatment method for lithium battery copper foil. Background Art

[0002] Electrolytic copper foil is a basic material for the electronics industry. As the basic conductive raw material for the production of printed circuit boards and lithium-ion batteries, it is a carrier for the mutual assembly of various electronic components and is called the "neural network" for signal and power transmission of electronic products. The passivation treatment of electrolytic copper foil is an important part of the production of electrolytic copper foil. The surface passivation treatment of electrolytic copper foil determines the corrosion resistance and high temperature oxidation resistance of electrolytic copper foil.

[0003] At present, chromic acid or chromate is one of the simplest and most practical film-forming methods. Although its process is mature and the passivation film has excellent corrosion resistance, hexavalent chromium is a strong carcinogen and will cause serious harm to the environment and human health. However, there are few studies on the chromium-free passivation process of copper foil in China. Therefore, the development and research of chromium-free passivation process technology is an innovation in metal passivation technology, the focus and hot spot of current research in the field of surface technology, and is also required for the promotion of green industrial technology and environmental protection.

[0004] In summary, it is necessary to propose an anti-oxidation liquid and an anti-oxidation treatment method for lithium battery copper foil to solve the above problems. Summary of the invention

[0005] The invention provides a new anti-oxidation treatment method for lithium battery copper foil, so as to reduce the harm to the environment and human health and realize the chromium-free passivation process of the copper foil.

[0006] The technical solution of the present invention is as follows: an anti-oxidation liquid for lithium battery copper foil, the anti-oxidation liquid comprises molybdate, phosphate, hydrogen peroxide, pH value regulator and water, and the anti-oxidation liquid is alkaline.

[0007] As a preferred technical solution of the present invention, each liter of the anti-oxidation liquid includes 5-15 g of molybdate, 5-20 g of phosphate, and 10-30 mL of hydrogen peroxide.

[0008] As a preferred technical solution of the present invention, the pH of the anti-oxidation liquid is 9-11.

[0009] As a preferred technical solution of the present invention, the anti-oxidation liquid includes 10 g / L of molybdate, 10 g / L of phosphate, and 15 mL / L of hydrogen peroxide, and the pH value of the anti-oxidation liquid is 10.

[0010] As a preferred technical solution of the present invention, the molybdate includes one or more of sodium molybdate, potassium molybdate, magnesium molybdate or ammonium molybdate.

[0011] As a preferred technical solution of the present invention, the phosphate includes one or more of sodium phosphate, potassium dihydrogen phosphate and sodium metaphosphate.

[0012] As a preferred technical solution of the present invention, the water is deionized water or purified water.

[0013] A method for anti-oxidation treatment of lithium battery copper foil comprises the following steps: Step 1: Prepare an aqueous solution with molybdate, phosphate, hydrogen peroxide and water, add a pH adjuster to the aqueous solution, adjust the aqueous solution to alkaline, and form an anti-oxidation solution, wherein the concentration of molybdate in the aqueous solution is 5-15 g / L, the concentration of phosphate is 5-20 g / L, and the concentration of hydrogen peroxide is 10-30 mL / L.

[0014] Step 2: Put the prepared anti-oxidation liquid into the anti-oxidation treatment tank, and after the anti-oxidation liquid is sufficient, put the copper foil into the anti-oxidation treatment tank for immersion and adsorption; Step 3: The copper foil after being soaked and adsorbed by the anti-oxidation liquid is taken out from the anti-oxidation treatment tank and dried.

[0015] As a preferred technical solution of the present invention, the prepared anti-oxidation liquid is input into the anti-oxidation treatment tank. After the anti-oxidation liquid is sufficient, the copper foil is placed in the anti-oxidation treatment tank for immersion and adsorption for 5-10s. The current density in the anti-oxidation treatment tank is 5-10mA / cm 2 .

[0016] As a preferred technical solution of the present invention, the copper foil after being soaked and adsorbed by the anti-oxidation liquid is led out from the anti-oxidation treatment tank, first squeezed to squeeze out the liquid remaining on the surface of the copper foil, and then dried.

[0017] The working principle and beneficial effects of the present invention are: The anti-oxidation liquid has a simple composition and will not produce waste liquid with complex composition when used for anti-oxidation treatment of the surface of copper foil, thereby reducing process difficulty and treatment cost; the anti-oxidation liquid is alkaline and the system is stable. At the same time, sodium molybdate, sodium phosphate and hydrogen peroxide work synergistically to quickly form a passivation layer on the surface of the copper foil, and while ensuring the anti-oxidation performance of the passivation layer, the corrosion resistance and high temperature resistance of the passivation film are also improved; in addition, the anti-oxidation liquid does not contain toxic substances, thereby avoiding negative effects on the health of users. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] An anti-oxidation liquid for lithium battery copper foil, comprising molybdate, phosphate, hydrogen peroxide, pH value regulator and water, wherein the anti-oxidation liquid is alkaline. Each liter of the anti-oxidation liquid comprises 5-15g of molybdate, 5-20g of phosphate and 10-30mL of hydrogen peroxide. The pH value of the anti-oxidation liquid is 9-11. The molybdate comprises one or more of sodium molybdate, potassium molybdate, magnesium molybdate or ammonium molybdate. The phosphate comprises one or more of sodium phosphate, potassium dihydrogen phosphate and sodium metaphosphate. The water is deionized water or purified water.

[0020] First, molybdate, phosphate, hydrogen peroxide and water are prepared into an aqueous solution, a pH adjuster is added to the aqueous solution, the aqueous solution is adjusted to be alkaline, and an anti-oxidation liquid is formed, wherein the concentration of molybdate in the aqueous solution is 5-15 g / L, the concentration of phosphate is 5-20 g / L, and the concentration of hydrogen peroxide is 10-30 mL / L; then, the prepared anti-oxidation liquid is input into an anti-oxidation treatment tank, and after the anti-oxidation liquid is sufficient, the copper foil is put into the anti-oxidation treatment tank for immersion and adsorption; finally, the copper foil after immersion and adsorption of the anti-oxidation liquid is led out from the anti-oxidation treatment tank and dried.

[0021] The prepared anti-oxidation liquid is input into the anti-oxidation treatment tank. After the anti-oxidation liquid is sufficient, the copper foil is placed in the anti-oxidation treatment tank for immersion and adsorption for 5-10 seconds. The current density in the anti-oxidation treatment tank is 5-10mA / cm 2 .

[0022] The copper foil after being soaked and adsorbed by the anti-oxidation liquid is led out from the anti-oxidation treatment tank, first squeezed to squeeze out the residual liquid on the surface of the copper foil, and then dried.

[0023] Example 1 The invention discloses an anti-oxidation liquid for lithium battery copper foil. The raw materials for preparing the anti-oxidation liquid include molybdate, phosphate, hydrogen peroxide, pH value regulator and water. The anti-oxidation liquid is alkaline.

[0024] The molybdate is sodium molybdate, and the mass concentration is 10 g / L.

[0025] The phosphate is sodium phosphate with a mass concentration of 10 g / L.

[0026] The mass concentration of hydrogen peroxide is 15mL / L.

[0027] The pH adjuster is sodium hydroxide, pH 10.

[0028] The anti-oxidation liquid also includes the following preparation method: placing molybdate, phosphate, hydrogen peroxide and pH adjuster in a reaction kettle according to mass concentration, stirring at a speed of 500r / min and a stirring time of 60min to obtain the anti-oxidation liquid.

[0029] The present invention also provides an application of a chromium-free passivating agent for lithium battery copper foil on lithium battery copper foil.

[0030] The passivation method is as follows: input the prepared anti-oxidation liquid into the anti-oxidation tank, and after adding a sufficient amount of anti-oxidation liquid, put the copper foil into the anti-oxidation treatment tank for immersion and adsorption, so that the surface of the copper foil can react with the anti-oxidation liquid to form a dense oxide film.

[0031] During the passivation treatment of copper foil, the current density in the anti-oxidation tank is 5-10mA / cm 2 .

[0032] The anti-oxidation treatment device also includes a first guide roller, a second guide roller, a third guide roller and an extrusion roller. The extrusion roller is arranged above the anti-oxidation treatment tank, the second guide roller is arranged in the anti-oxidation treatment tank, the third guide roller is arranged above the outlet of the anti-oxidation treatment tank, and the extrusion roller is located above the third guide roller. The second guide roller is below the liquid surface of the anti-oxidation liquid. When the copper foil is passivated, the copper foil is introduced into the anti-oxidation tank through the first guide roller, and is immersed and adsorbed in the anti-oxidation treatment tank for 5-10 seconds and then led out through the second guide roller. The copper foil passes through the third guide roller and the extrusion roller to squeeze out the anti-oxidation liquid remaining on the surface of the copper foil. Then it is dried by the drying device and rolled up.

[0033] Example 2 The invention discloses an anti-oxidation liquid for lithium battery copper foil. The raw materials for preparing the anti-oxidation liquid include molybdate, phosphate, hydrogen peroxide and pH value regulator.

[0034] The molybdate is sodium molybdate, and the mass concentration is 10 g / L.

[0035] The phosphate is sodium phosphate with a mass concentration of 15 g / L.

[0036] The mass concentration of hydrogen peroxide is 10mL / L.

[0037] The pH adjuster is sodium carbonate, pH 9.

[0038] The anti-oxidation liquid also includes the following preparation method: placing molybdate, phosphate, hydrogen peroxide and pH adjuster in a reaction kettle according to mass concentration, stirring at a speed of 500r / min and a stirring time of 60min to obtain the anti-oxidation liquid.

[0039] The present invention also provides an application of a chromium-free passivating agent for lithium battery copper foil on lithium battery copper foil.

[0040] The passivation method is as follows: input the prepared anti-oxidation liquid into the anti-oxidation tank, and after adding a sufficient amount of anti-oxidation liquid, put the copper foil into the anti-oxidation treatment tank for immersion and adsorption, so that the surface of the copper foil can react with the anti-oxidation liquid to form a dense oxide film.

[0041] During the passivation treatment of copper foil, the current density in the anti-oxidation tank is 5-10mA / cm2.

[0042] The anti-oxidation treatment device also includes a first guide roller, a second guide roller, a third guide roller and an extrusion roller. The extrusion roller is arranged above the anti-oxidation treatment tank. The second guide roller is arranged in the anti-oxidation treatment tank. The third guide roller is arranged above the outlet of the anti-oxidation treatment tank. The extrusion roller is arranged above the third guide roller. The second guide roller is below the liquid surface of the anti-oxidation liquid. When the copper foil is passivated, the copper foil is introduced into the anti-oxidation tank through the first guide roller, and is led out after being immersed and adsorbed in the anti-oxidation treatment tank for 5-10 seconds through the second guide roller. The copper foil passes through the third guide roller and the extrusion roller to squeeze out the anti-oxidation liquid remaining on the surface of the copper foil. Then it is dried by the drying device and rolled up.

[0043] Example 3 The invention discloses an anti-oxidation liquid for lithium battery copper foil. The raw materials for preparing the anti-oxidation liquid include molybdate, phosphate, hydrogen peroxide and pH value regulator.

[0044] The molybdate is sodium molybdate, and the mass concentration is 15 g / L.

[0045] The phosphate is sodium phosphate with a mass concentration of 10 g / L.

[0046] The mass concentration of hydrogen peroxide is 20mL / L.

[0047] The pH adjuster is sodium hydroxide, pH 11.

[0048] The anti-oxidation liquid also includes the following preparation method: placing molybdate, phosphate, hydrogen peroxide and pH adjuster in a reaction kettle according to mass concentration, stirring at a speed of 500r / min and a stirring time of 60min to obtain the anti-oxidation liquid.

[0049] The present invention also provides an application of a chromium-free passivating agent for lithium battery copper foil on lithium battery copper foil.

[0050] The passivation method is as follows: input the prepared anti-oxidation liquid into the anti-oxidation tank, and after adding a sufficient amount of anti-oxidation liquid, put the copper foil into the anti-oxidation treatment tank for immersion and adsorption, so that the surface of the copper foil can react with the anti-oxidation liquid to form a dense oxide film.

[0051] During the passivation treatment of copper foil, the current density in the anti-oxidation tank is 5-10mA / cm 2 .

[0052] The anti-oxidation treatment device also includes a first guide roller, a second guide roller, a third guide roller and an extrusion roller. The extrusion roller is arranged above the anti-oxidation treatment tank. The second guide roller is arranged in the anti-oxidation treatment tank. The third guide roller is arranged above the outlet of the anti-oxidation treatment tank. The extrusion roller is arranged above the third guide roller. The second guide roller is below the liquid surface of the anti-oxidation liquid. When the copper foil is passivated, the copper foil is introduced into the anti-oxidation tank through the first guide roller, and is led out after being immersed and adsorbed in the anti-oxidation treatment tank for 5-10 seconds through the second guide roller. The copper foil passes through the third guide roller and the extrusion roller to squeeze out the anti-oxidation liquid remaining on the surface of the copper foil. Then it is dried by the drying device and rolled up.

[0053] Example 4 The invention discloses an anti-oxidation liquid for lithium battery copper foil. The raw materials for preparing the anti-oxidation liquid include molybdate, phosphate, hydrogen peroxide and pH value regulator.

[0054] The molybdate is sodium molybdate, and the mass concentration is 10 g / L.

[0055] The phosphate is sodium phosphate with a mass concentration of 15 g / L.

[0056] The mass concentration of hydrogen peroxide is 20mL / L.

[0057] The pH adjuster is sodium hydroxide, pH 10.

[0058] The anti-oxidation liquid also includes the following preparation method: placing molybdate, phosphate, hydrogen peroxide and pH adjuster in a reaction kettle according to mass concentration, stirring at a speed of 500r / min and a stirring time of 60min to obtain the anti-oxidation liquid.

[0059] The present invention also provides an application of a chromium-free passivating agent for lithium battery copper foil on lithium battery copper foil.

[0060] The passivation method is as follows: input the prepared anti-oxidation liquid into the anti-oxidation tank, and after adding a sufficient amount of anti-oxidation liquid, put the copper foil into the anti-oxidation treatment tank for immersion and adsorption, so that the surface of the copper foil can react with the anti-oxidation liquid to form a dense oxide film.

[0061] During the passivation treatment of copper foil, the current density in the anti-oxidation tank is 5-10mA / cm 2 .

[0062] The anti-oxidation treatment device also includes a first guide roller, a second guide roller, a third guide roller and an extrusion roller. The extrusion roller is arranged above the anti-oxidation treatment tank. The second guide roller is arranged in the anti-oxidation treatment tank. The third guide roller is arranged above the outlet of the anti-oxidation treatment tank. The extrusion roller is arranged above the third guide roller. The second guide roller is below the liquid surface of the anti-oxidation liquid. When the copper foil is passivated, the copper foil is introduced into the anti-oxidation tank through the first guide roller, and is led out after being immersed and adsorbed in the anti-oxidation treatment tank for 5-10 seconds through the second guide roller. The copper foil passes through the third guide roller and the extrusion roller to squeeze out the anti-oxidation liquid remaining on the surface of the copper foil. Then it is dried by the drying device and rolled up.

[0063] Comparative Example 1 The concentration of sodium molybdate was changed to 3 g / L, the concentration of sodium phosphate was changed to 25 g / L, and the rest was the same as in Example 1.

[0064] Comparative Example 2 The concentration of sodium phosphate was changed to 40 ml / L of hydrogen peroxide, and the rest was the same as in Example 1.

[0065] Comparative Example 3 The concentration of sodium molybdate was changed to 5 g / L, the concentration of hydrogen peroxide was changed to 5 ml / L, and the rest was the same as in Example 1.

[0066] Comparative Example 4 The concentration of molybdate was changed to 5 g / L, the concentration of sodium phosphate was 5 g / L, and the rest was the same as in Example 1.

[0067] Performance evaluation: (1) Anti-oxidation performance test: Place the passivated copper foil in an air-circulating constant temperature box at 140°C. When the temperature of the constant temperature box rises to the specified temperature, start timing and observe and record whether the two sides of the double-sided copper foil are oxidized and discolored.

[0068] (2) Salt spray corrosion resistance test: The pH value of sodium chloride is 6.8. The sodium chloride solution is atomized to form a neutral salt spray with a concentration of 10%. The passivated double-sided copper foil is placed in a neutral salt spray tester for spray testing. The test is left to stand for 72 hours. The time it takes for corrosion to appear on the sample surface is observed and recorded. The longer the time, the better the salt spray resistance.

[0069] The test results of the antioxidant performance time (min) and the salt spray resistance performance time (h) in the above embodiment are shown in Table 1 below: Test items Antioxidant performance time (min) Salt spray resistance time (h) Example 1 15 72 Example 2 15 72 Example 3 15 72 Example 4 15 72 Comparative Example 1 5 48 Comparative Example 2 10 54 Comparative Example 3 5 48 Comparative Example 4 8 45 The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-oxidation liquid for lithium battery copper foil, characterized in that: The anti-oxidation liquid comprises molybdate, phosphate, hydrogen peroxide, pH value adjuster and water, and the anti-oxidation liquid is alkaline.

2. The anti-oxidation liquid according to claim 1, characterized in that: Each liter of the anti-oxidation liquid contains 5-15 g of molybdate, 5-20 g of phosphate, and 10-30 mL of hydrogen peroxide.

3. The anti-oxidation liquid according to claim 1, characterized in that: The pH of the anti-oxidation liquid is 9-11.

4. The anti-oxidation liquid according to claim 1, characterized in that: The anti-oxidation liquid comprises 10 g / L of molybdate, 10 g / L of phosphate, and 15 mL / L of hydrogen peroxide, and the pH value of the anti-oxidation liquid is 10.

5. The anti-oxidation liquid according to claim 1, characterized in that: The molybdate includes one or more of sodium molybdate, potassium molybdate, magnesium molybdate or ammonium molybdate.

6. The anti-oxidation liquid according to claim 1, characterized in that: The phosphate includes one or more of sodium phosphate, potassium dihydrogen phosphate and sodium metaphosphate.

7. The anti-oxidation liquid according to claim 1, characterized in that: The water is deionized water or purified water.

8. A method for anti-oxidation treatment of lithium battery copper foil, characterized in that: The following steps are involved: Step 1: Prepare an aqueous solution of molybdate, phosphate, hydrogen peroxide and water, add a pH adjuster to the aqueous solution, adjust the aqueous solution to alkaline, and form an anti-oxidation solution, wherein the concentration of molybdate in the aqueous solution is 5-15g / L, the concentration of phosphate is 5-20g / L, and the concentration of hydrogen peroxide is 10-30mL / L. Step 2: Input the prepared anti-oxidation solution into the anti-oxidation treatment tank, and after the anti-oxidation solution is sufficient, put the copper foil into the anti-oxidation treatment tank for soaking and adsorption; Step 3: Take out the copper foil after soaking and adsorption of the anti-oxidation solution from the anti-oxidation treatment tank and dry it.

9. The anti-oxidation treatment method according to claim 8, characterized in that: The prepared anti-oxidation liquid is input into the anti-oxidation treatment tank. After the anti-oxidation liquid is sufficient, the copper foil is put into the anti-oxidation treatment tank for immersion and adsorption for 5-10s. The current density in the anti-oxidation treatment tank is 5-10mA / cm 2 .

10. The anti-oxidation treatment method according to claim 8 or 9, characterized in that: The copper foil after being soaked and adsorbed by the anti-oxidation liquid is led out from the anti-oxidation treatment tank, first squeezed to squeeze out the residual liquid on the surface of the copper foil, and then dried.