A copper foil, a preparation method thereof and an application thereof

Abstract

The present invention discloses a copper foil, a preparation method thereof and an application thereof, relating to the technical field of copper foils. The preparation method of the copper foil comprises: dissolving copper sulfate and zinc sulfate in deionized water to prepare a copper-zinc mixed solution, and dissolving a complexing agent in a potassium hydroxide solution to obtain a complexing agent mixed solution; adding the copper-zinc mixed solution into the complexing agent mixed solution to obtain an electrolyte solution; providing an electrodeposition device, using a brass plate as the anode and a titanium plate as the cathode, adopting a regulated DC power supply, stirring at room temperature, adding a stabilizer and an additive, and electrodepositing the electrolyte solution to obtain a copper-zinc alloy; immersing the copper-zinc alloy in a sodium hydroxide solution and then in a hydrochloric acid solution to obtain a copper foil. The present invention can solve the technical problems that in the prior art, the addition of an organic additive will affect the conductivity of the electrolyte solution, resulting in the inability to detect the flow rate by an electromagnetic flowmeter or a large deviation between the actual value and the set flow rate value, thus affecting the stability and adjustment of the process.

Description

Technical Field

[0001] The present invention relates to the technical field of copper foils, and particularly relates to a copper foil, a preparation method thereof, and an application thereof. Background Art

[0002] Copper foils are mainly used as the negative current collectors of lithium batteries to improve the performance of the batteries. At present, due to the porous structure, the planar structure is transformed into a three-dimensional structure, increasing the specific surface area, regulating the nucleation sites, shortening the mass transfer distance, thereby reducing the local current, inhibiting dendrite growth, and improving the cycle performance and Coulomb efficiency of lithium batteries. In addition, copper foils are also used in many fields such as the electronics industry, the construction industry, and the packaging industry, such as the production of electronic components such as printed circuit boards, integrated circuits, and capacitors, as well as building applications such as roofs, exterior walls, and interior walls, improving the durability and aesthetics of buildings.

[0003] Existing copper foils are generally prepared by the hydrogen bubble template method under low copper, high acid, and high current density conditions. Additives such as NH4 + , Cl - , PEG (polyethylene glycol), 3-mercapto-1-propanesulfonic acid (MPSA), etc. are added to improve the compactness of the copper foil, reduce the roughness, and enhance the comprehensive performance of the copper foil. However, the addition of organic additives will affect the conductivity of the electrolyte, resulting in problems such as the electromagnetic flowmeter being unable to detect the flow rate or a large deviation between the actual value and the set flow rate value, affecting the stability and adjustment of the process. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a copper foil, a preparation method thereof, and an application thereof, aiming to solve the technical problem that the addition of organic additives in the existing technology will affect the conductivity of the electrolyte, resulting in problems such as the electromagnetic flowmeter being unable to detect the flow rate or a large deviation between the actual value and the set flow rate value, affecting the stability and adjustment of the process.

[0005] The first aspect of the present invention is to provide a preparation method of a copper foil, and the preparation method includes:

[0006] Dissolve copper sulfate and zinc sulfate in deionized water to prepare a copper-zinc mixed solution, and dissolve a complexing agent in a potassium hydroxide solution with a first preset concentration to obtain a complexing agent mixed solution;

[0007] Add the copper-zinc mixed solution to the complexing agent mixed solution to obtain an electrolyte;

[0008] Provide an electrodeposition device, use a brass plate as the anode, a titanium plate as the cathode, adopt a regulated DC power supply, stir at room temperature, add a stabilizer and an additive, and electrodeposit the electrolyte for a first preset time at a preset deposition temperature and a preset current density to obtain a copper-zinc alloy;

[0009] Immerse the copper-zinc alloy in a sodium hydroxide solution with a second preset concentration for a second preset time, and then immerse it in a hydrochloric acid solution with a third preset concentration for a third preset time to obtain a copper foil.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the copper foil preparation method provided by the present invention, the stability of the process can be effectively improved. Specifically, by forming a stable complex with copper ions, the cathodic polarization of copper ions in electrolysis is enhanced, promoting the deposition of copper ions. Then, potassium hydroxide can form Zn(OH)4 2- existing in the solution in the form of, and the deposition potential will also shift positively, which will further narrow the deposition potential difference between copper ions and zinc ions, achieving the purpose of co-deposition, improving the stability of the process, and by adding a stabilizer, the electrical conductivity can be effectively enhanced, improving the problem that the flowmeter cannot detect and the fluctuation value is too large, improving the process stability. By adding additives, the generation of cracks can be effectively reduced, ion migration can be accelerated, and the crystallization nucleation of copper-zinc alloy can be promoted, achieving the effects of improving the density and refining the grains, and further improving the process stability, thereby solving the technical problems in the prior art that the addition of organic additives will affect the electrical conductivity of the electrolyte, resulting in the flowmeter being unable to detect the flow or the actual value deviating greatly from the set flow value, affecting the stability and adjustment of the process.

[0011] According to one aspect of the above technical solution, the step of dissolving copper sulfate and zinc sulfate in deionized water to prepare a copper-zinc mixed solution specifically includes:

[0012] Dissolve copper sulfate and zinc sulfate in deionized water to prepare a copper-zinc mixed solution, wherein the concentration of copper sulfate is 0.01 mol / L - 1 mol / L, the concentration of zinc sulfate is 0.01 mol / L - 1 mol / L, and the concentration ratio of copper sulfate to zinc sulfate is (0.5 - 3):1.

[0013] According to one aspect of the above technical solution, the first preset concentration is 2 mol / L - 4 mol / L, the complexing agent is maltitol, and in the complexing agent mixed solution, the concentration of the complexing agent is 0.05 mol / L - 0.5 mol / L.

[0014] According to one aspect of the above technical solution, the complexing agent is maltitol, and in the complexing agent mixed solution, the concentration of the complexing agent is 0.05 mol / L - 0.5 mol / L.

[0015] According to one aspect of the above technical solution, the stabilizer is copper sulfate crystal, and the concentration of the stabilizer is 10 g / L - 50 g / L.

[0016] According to one aspect of the above technical solution, the additive includes sodium hexametaphosphate and glycine. The concentration of sodium hexametaphosphate is 5 mg / L - 12 mg / L, and the concentration of glycine is 1 mg / L - 5 mg / L.

[0017] According to one aspect of the above technical solution, the preset deposition temperature is 30°C - 50°C, and the preset current density is 1 A / dm 2 - 4 A / dm 2 , and the first preset time is 5 min - 20 min.

[0018] According to one aspect of the above technical solution, the second preset concentration is 0.5 mol / L - 2 mol / L, the second preset time is 4 h - 10 h, the third preset concentration is 0.5 mol / L - 2 mol / L, and the third preset time is 1 min - 5 min.

[0019] The second aspect of the present invention is to provide a copper foil, which is prepared by the above method for preparing a copper foil.

[0020] The third aspect of the present invention is to provide an application of the above copper foil in a lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0022] Figure 1 is a flowchart of the method for preparing the copper foil of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] To make the objectives, features, and advantages of the present invention more obvious and understandable, the following provides a detailed description of the specific embodiments of the present invention with reference to the drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0024] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right", "upper", "lower", and similar expressions used herein are only for the purpose of illustration and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention.

[0025] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0026] Please refer to Figure 1 , which shows a method for preparing a copper foil provided by the present invention. The preparation method includes: steps S10 - S13,

[0027] Step S10: Dissolve copper sulfate and zinc sulfate in deionized water to prepare a copper-zinc mixed solution, and dissolve a complexing agent in a potassium hydroxide solution with a first preset concentration to obtain a complexing agent mixed solution;

[0028] Among them, setting the ratio of copper sulfate and zinc sulfate can effectively improve the performance of the copper-zinc alloy, reduce the generation of cracks, and facilitate the subsequent formation of the copper foil.

[0029] Preferably, in the copper-zinc mixed solution, the concentration of copper sulfate is 0.01 mol / L - 1 mol / L, and the concentration of zinc sulfate is 0.01 mol / L - 1 mol / L. For example, it can be 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.5 mol / L, 0.7 mol / L or 1 mol / L, but not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0030] Furthermore, the concentration ratio of copper sulfate and zinc sulfate is (0.5 - 3):1.

[0031] In addition, the complexing agent is maltitol. Maltitol has a polyhydroxy structure and can coordinate with copper ions to form a stable complex, enhancing the cathodic polarization of copper ions in electrolysis and promoting the deposition of copper ions.

[0032] Preferably, in the complexing agent mixed solution, the concentration of the complexing agent is 0.05 mol / L - 0.5 mol / L. For example, it can be 0.05 mol / L, 0.1 mol / L, 0.2 mol / L or 0.5 mol / L, but not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0033] Furthermore, potassium hydroxide can form Zn(OH)4 with zinc ions 2-If it exists in the solution in the form, the deposition potential will shift positively, further narrowing the deposition potential difference between copper ions and zinc ions to achieve the purpose of co - deposition.

[0034] Preferably, the first preset concentration is 2 mol / L - 4 mol / L. For example, it can be 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L or 4 mol / L, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0035] Step S11: Add the copper - zinc mixed solution to the complexing agent mixed solution to obtain an electrolyte solution.

[0036] Step S12: Provide an electro - deposition device. Use a brass plate as the anode and a titanium plate as the cathode. Adopt a regulated DC power supply, stir at room temperature, add a stabilizer and additives, and electro - deposit the electrolyte solution for a first preset time at a preset deposition temperature and a preset current density to obtain a copper - zinc alloy.

[0037] Among them, the stabilizer is copper sulfate crystal. In order to improve the performance of the electrolytic copper - zinc alloy, complexing agents and additives will be added. However, the organic substances or ions in the complexing agents and additives will affect the conductivity of the electrolyte solution, resulting in problems such as the electromagnetic flowmeter being unable to detect the flow rate or a large deviation between the actual value and the set flow rate value, affecting the stability and adjustment of the process. Adding an appropriate amount of copper sulfate crystal can effectively enhance the conductivity, improve the problem that the flowmeter cannot detect and the fluctuation value is too large. Secondly, the addition of copper sulfate crystal will not introduce new impurities and improve the purity of the copper - zinc alloy.

[0038] Preferably, the concentration of the stabilizer is 10 g / L - 50 g / L. For example, it can be 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L or 50 g / L, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0039] Furthermore, the additives include sodium hexametaphosphate and glycine. Sodium hexametaphosphate is a surfactant, which can effectively reduce the surface tension of the electrolyte solution, reduce the deposition potential of the copper - zinc alloy, accelerate the migration of ions, promote the crystallization nucleation of the copper - zinc alloy, and improve the density and grain size of the copper - zinc alloy. Glycine will reduce the stress in the electrolyte solution and act as a brightening agent, reducing the cracks generated due to stress during the deposition of the copper - zinc alloy. Through the synergistic effect of the additives, the generation of cracks can be effectively reduced, the ion migration can be accelerated, the crystallization nucleation of the copper - zinc alloy can be promoted, and the effects of improving the density and refining the grain size can be achieved.

[0040] Preferably, the concentration of the sodium hexametaphosphate is 5 mg / L - 12 mg / L. For example, it can be 5 mg / L, 6 mg / L, 7 mg / L, 8 mg / L, 9 mg / L, 10 mg / L, 11 mg / L or 12 mg / L. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0041] Preferably, the concentration of the glycine is 1 mg / L - 5 mg / L. For example, it can be 1 mg / L, 2 mg / L, 3 mg / L, 4 mg / L or 5 mg / L. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0042] Step S13: Immerse the copper-zinc alloy in a sodium hydroxide solution with a second preset concentration for a second preset time, and then immerse it in a hydrochloric acid solution with a third preset concentration for a third preset time to obtain a copper foil.

[0043] Among them, zinc in the copper-zinc alloy is removed by the sodium hydroxide solution and the hydrochloric acid solution.

[0044] The second preset concentration is 0.5 mol / L - 2 mol / L, the second preset time is 4 h - 10 h, the third preset concentration is 0.5 mol / L - 2 mol / L, and the third preset time is 1 min - 5 min. Zinc in the copper-zinc alloy is removed by a low-concentration sodium hydroxide solution and a low-concentration hydrochloric acid solution to reduce the generation of cracks in the copper-zinc alloy and reduce the collapse of the copper foil.

[0045] Correspondingly, the present invention provides a copper foil prepared by the above-mentioned preparation method of the copper foil. A preparation method for preparing the above-mentioned copper foil.

[0046] Among them, the thickness of the copper foil is 2 μm - 5 μm, the specific surface area is 15 m 2 / g - 20 m 2 / g, the pore volume is 0.03 cm 2 / g - 0.05 cm 2 / g, and the pore diameter is 120 nm - 170 nm.

[0047] In addition, the present invention also provides an application of the above-mentioned copper foil in a lithium battery.

[0048] The following further illustrates the present invention with specific examples:

[0049] Example 1

[0050] The preparation method of the copper foil provided in the first embodiment of the present invention includes steps S10 - S13.

[0051] Step S10: Dissolve copper sulfate and zinc sulfate in deionized water to prepare a copper-zinc mixed solution, and dissolve the complexing agent in a potassium hydroxide solution with a first preset concentration to obtain a complexing agent mixed solution;

[0052] Among them, in the copper-zinc mixed solution, the concentration of copper sulfate is 0.2 mol / L, and the concentration of zinc sulfate is 0.09 mol / L.

[0053] Furthermore, the concentration ratio of copper sulfate to zinc sulfate is 2.22:1.

[0054] In addition, the complexing agent is maltitol. In the complexing agent mixed solution, the concentration of the complexing agent is 0.2 mol / L, and the first preset concentration is 3 mol / L.

[0055] Step S11: Add the copper-zinc mixed solution to the complexing agent mixed solution to obtain an electrolyte;

[0056] Among them, the copper-zinc mixed solution and the complexing agent mixed solution are mixed in equal volumes.

[0057] Step S12: Provide an electrodeposition device. Use a brass plate as the anode and a titanium plate as the cathode. Adopt a regulated DC power supply, stir at room temperature, add a stabilizer and an additive, and electrodeposit the electrolyte for a first preset time at a preset deposition temperature and a preset current density to obtain a copper-zinc alloy;

[0058] Among them, the stabilizer is copper sulfate crystal, and the concentration of the stabilizer is 5 g / L.

[0059] Furthermore, the additive includes sodium hexametaphosphate and glycine. The concentration of sodium hexametaphosphate is 10 mg / L, and the concentration of glycine is 3 mg / L.

[0060] Step S13: Immerse the copper-zinc alloy in a sodium hydroxide solution with a second preset concentration for a second preset time, and then immerse it in a hydrochloric acid solution with a third preset concentration for a third preset time to obtain a copper foil.

[0061] Among them, the second preset concentration is 1 mol / L, the second preset time is 8 h, the third preset concentration is 1 mol / L, and the third preset time is 2 min.

[0062] Example 2

[0063] The second embodiment of the present invention provides a method for preparing a copper foil. The difference between the method for preparing a copper foil in this embodiment and the method for preparing a copper foil in the first embodiment is that:

[0064] In the copper-zinc mixed solution, the concentration of copper sulfate is 0.3 mol / L, and the concentration of zinc sulfate is 0.09 mol / L.

[0065] Example III

[0066] The third embodiment of the present invention provides a method for preparing copper foil. The difference between the method for preparing copper foil in this embodiment and that in the first embodiment is as follows:

[0067] In the copper-zinc mixed solution, the concentration of copper sulfate is 0.2 mol / L, and the concentration of zinc sulfate is 0.15 mol / L.

[0068] Example IV

[0069] The fourth embodiment of the present invention provides a method for preparing copper foil. The difference between the method for preparing copper foil in this embodiment and that in the first embodiment is as follows:

[0070] The concentration of the complexing agent is 0.1 mol / L.

[0071] Example V

[0072] The fifth embodiment of the present invention provides a method for preparing copper foil. The difference between the method for preparing copper foil in this embodiment and that in the first embodiment is as follows:

[0073] The concentration of the complexing agent is 0.5 mol / L.

[0074] Example VI

[0075] The sixth embodiment of the present invention provides a method for preparing copper foil. The difference between the method for preparing copper foil in this embodiment and that in the first embodiment is as follows:

[0076] The concentration of the stabilizer is 1 g / L.

[0077] Example VII

[0078] The seventh embodiment of the present invention provides a method for preparing copper foil. The difference between the method for preparing copper foil in this embodiment and that in the first embodiment is as follows:

[0079] The concentration of the stabilizer is 10 g / L.

[0080] Example VIII

[0081] The eighth embodiment of the present invention provides a method for preparing copper foil. The difference between the method for preparing copper foil in this embodiment and that in the first embodiment is as follows:

[0082] The concentration of sodium hexametaphosphate is 5 mg / L, and the concentration of glycine is 1 mg / L.

[0083] Example IX

[0084] The ninth embodiment of the present invention provides a method for preparing a copper foil. The difference between the method for preparing the copper foil in this embodiment and that in the first embodiment is as follows:

[0085] The concentration of the sodium hexametaphosphate is 12 mg / L, and the concentration of the glycine is 5 mg / L.

[0086] Comparative Example 1

[0087] The first comparative example of the present invention provides a method for preparing a copper foil. The difference between the method for preparing the copper foil in this embodiment and that in the first embodiment is as follows:

[0088] No complexing agent is added.

[0089] Comparative Example 2

[0090] The second comparative example of the present invention provides a method for preparing a copper foil. The difference between the method for preparing the copper foil in this embodiment and that in the first embodiment is as follows:

[0091] No stabilizer is added.

[0092] Comparative Example 3

[0093] The third comparative example of the present invention provides a method for preparing a copper foil. The difference between the method for preparing the copper foil in this embodiment and that in the first embodiment is as follows:

[0094] No additive is added.

[0095] Comparative Example 4

[0096] The fourth comparative example of the present invention provides a method for preparing a copper foil. The difference between the method for preparing the copper foil in this embodiment and that in the first embodiment is as follows:

[0097] No sodium hexametaphosphate is added.

[0098] Comparative Example 5

[0099] The fifth comparative example of the present invention provides a method for preparing a copper foil. The difference between the method for preparing the copper foil in this embodiment and that in the first embodiment is as follows:

[0100] No glycine is added.

[0101] Please refer to Table 1 below, which shows the corresponding parameters of the above-mentioned Embodiments 1 to 9 and Comparative Examples 1 to 5 of the present invention.

[0102] Table 1

[0103]

[0104]

[0105] Combined with the data of Examples 1 to 9 and Comparative Examples 1 to 5, it can be seen that using the preparation method of the copper foil of the present invention can effectively increase the pore diameter and porosity and reduce the generation of cracks.

[0106] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0107] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A method for preparing copper foil, characterized in that, The preparation method includes: Dissolve copper sulfate and zinc sulfate in deionized water to prepare a copper-zinc mixed solution, and dissolve the complexing agent in a potassium hydroxide solution with a first preset concentration to obtain a complexing agent mixed solution. Among them, the concentration of copper sulfate is 0.01 mol / L - 1 mol / L, the concentration of zinc sulfate is 0.01 mol / L - 1 mol / L, the concentration ratio of copper sulfate to zinc sulfate is (0.5 - 3):1, the first preset concentration is 2 mol / L - 4 mol / L, the complexing agent is maltitol, and in the complexing agent mixed solution, the concentration of the complexing agent is 0.05 mol / L - 0.5 mol / L; Add the copper-zinc mixed solution to the complexing agent mixed solution to obtain an electrolyte; Provide an electroplating device, use a brass plate as the anode and a titanium plate as the cathode, adopt a regulated DC power supply, stir at room temperature, add a stabilizer and an additive, and electroplate the electrolyte for a first preset time at a preset deposition temperature and a preset current density to obtain a copper-zinc alloy. Among them, the stabilizer is copper sulfate crystal, the additive includes sodium hexametaphosphate and glycine, the concentration of sodium hexametaphosphate is 10 mg / L, and the concentration of glycine is 3 mg / L; Immerse the copper-zinc alloy in a sodium hydroxide solution with a second preset concentration for a second preset time, and then immerse it in a hydrochloric acid solution with a third preset concentration for a third preset time to obtain a copper foil.

2. The method for preparing a copper foil according to claim 1, wherein The preset deposition temperature is 30°C - 50°C, and the preset current density is 1 A / dm 2 - 4 A / dm 2 , and the first preset time is 5 min - 20 min.

3. The method for preparing a copper foil according to claim 1, wherein, The second preset concentration is 0.5 mol / L - 2 mol / L, the second preset time is 4 h - 10 h, the third preset concentration is 0.5 mol / L - 2 mol / L, and the third preset time is 1 min - 5 min.

4. A copper foil, characterized in that, The copper foil is prepared by the preparation method of the copper foil according to any one of claims 1 - 3.

5. An application of the copper foil according to claim 4 in a lithium battery.

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