Method for preparing copper-nickel alloy for solid-state battery through alkaline system
By preparing copper-nickel alloys through electrodeposition in an alkaline system, the problem of easy corrosion of copper foil in sulfide solid-state lithium batteries was solved, and a high-strength and high-ductility copper-nickel alloy was achieved, which improved the battery's service life and cost competitiveness.
Patent Information
- Application Number
- CN202510984813.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2025-10-31
AI Technical Summary
In existing technologies, copper foil is easily corroded in sulfide solid-state lithium batteries, and its tensile strength and elongation are insufficient, resulting in a short service life. In addition, stainless steel and pure nickel foil are expensive, which affects the competitiveness of solid-state lithium batteries.
Copper-nickel alloys were prepared in an alkaline system by electrodeposition using an aqueous pyrophosphate solution as the electrolyte. Sodium saccharin, 2-mercaptobenzimidazole, and 2-mercaptobenzothiazole were added. By adjusting parameters such as current density, pH value, and electrode spacing, copper-nickel alloys with tensile strength greater than 1000 MPa and elongation greater than 5% were prepared.
It achieves high strength and high ductility of copper-nickel alloy, suitable for sulfide solid-state batteries, reduces costs and improves battery corrosion resistance and conductivity, making it suitable for large-scale industrial production.
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Figure CN120866895A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solid-state battery technology, specifically relating to a method for preparing copper-nickel alloys for solid-state batteries using an alkaline system. Background Technology
[0002] Solid-state batteries (SSDs) offer advantages such as high safety, high energy density, and long lifespan, and are considered a crucial direction for next-generation battery technology. Based on their electrolyte systems, SSDs can be classified into oxide SSDs, sulfide SSDs, and polymer SSDs. Sulfide SSDs have attracted significant attention due to their ultra-high room-temperature ionic conductivity and good machinability. Currently, lithium-ion batteries generally use copper foil as the negative electrode current collector. However, copper foil is easily corroded by the sulfide SSDs in SSDs, resulting in a short lifespan and reducing the overall lifespan of the SSD battery. Furthermore, the tensile strength of current copper foil is below 1000 MPa, and its elongation is below 4.5%, which is insufficient to meet the requirements for negative electrode current collectors in SSDs. Therefore, sulfide SSDs require the use of stainless steel foil, nickel foil, or copper-nickel alloy foil to prevent sulfur corrosion. Since stainless steel and pure nickel products are expensive, affecting cost competitiveness, copper-nickel alloy foil offers significant advantages in improving the surface corrosion resistance and conductivity of the current collector in sulfide SSD batteries.
[0003] If the deposition potentials of the two metals differ too much, the metal with the more positive potential will be deposited preferentially, and may even completely repel the deposition of the metal with the more negative potential, thus preventing the formation of an alloy coating. The standard electrode potential of copper is 0.337V, while that of nickel is -0.25V, with copper having a potential approximately 0.6V higher than nickel. Therefore, it is essential to research a preparation process to achieve the co-deposition of copper and nickel metal ions and develop a copper-nickel alloy with a tensile strength greater than 1000 MPa and an elongation greater than 5% suitable for sulfide solid-state batteries. Summary of the Invention
[0004] To address the aforementioned problems in the prior art, this invention provides a method for preparing copper-nickel alloys for solid-state batteries using an alkaline system.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] One of the technical solutions of this invention is a method for preparing copper-nickel alloys for solid-state batteries using an alkaline system. The method uses a pyrophosphate aqueous solution system as the electrolyte and prepares the copper-nickel alloy by electrodeposition. The pyrophosphate aqueous solution system includes the following components: raw materials copper pyrophosphate and nickel chloride, main complexing agent potassium pyrophosphate, auxiliary complexing agent ethylenediaminetetraacetic acid or potassium sodium tartrate, and also includes brighteners and additives.
[0007] As a preferred embodiment of the present invention, the brightener comprises sodium saccharin, and the additive comprises 2-mercaptobenzimidazole and 2-mercaptobenzothiazole; in the pyrophosphate aqueous solution system, the concentrations of each component are as follows: copper pyrophosphate 10-20 g / L, nickel chloride 20-40 g / L, sodium saccharin 2-5 g / L, potassium pyrophosphate 320-380 g / L, 2-mercaptobenzimidazole 2-4 mg / L, 2-mercaptobenzothiazole 3-5 mg / L, and auxiliary complexing agent ethylenediaminetetraacetic acid 2-10 g / L or potassium sodium tartrate 60-80 g / L.
[0008] As a preferred embodiment of the present invention, the electrolyte has a circulation rate of 500-800 mL / min and a pH value of 8-10.
[0009] As a preferred technical solution of the present invention, when preparing copper-nickel alloy by electrodeposition, a rotating cathode titanium roller is used as the copper plating cathode, and an oxygen-evolving copper plate and a nickel plate are used as the anode, with a distance of 1 to 4 cm between the positive and negative electrodes.
[0010] As a preferred embodiment of the present invention, when preparing copper-nickel alloys by electrodeposition, the current density is 3.0–11.0 A / dm³. 2 The electrolyte temperature is 50–55℃, and the electrodeposition time is 10–25 min.
[0011] As a preferred technical solution of the present invention, the copper-nickel alloy for solid-state batteries has a thickness of 4.5 to 18 μm, a nickel content of 3.14 to 8.93 wt%, and a tensile strength >1000 MPa.
[0012] The second technical solution of the present invention is a copper-nickel alloy prepared by the method for preparing a solid-state battery copper-nickel alloy according to the alkaline system described above.
[0013] The third technical solution of the present invention is an application of the copper-nickel alloy described above in the preparation of solid-state batteries, especially in the preparation of sulfide solid-state batteries.
[0014] The fourth technical solution of the present invention is a solid-state battery that uses the copper-nickel alloy described above as the negative electrode current collector.
[0015] As a preferred embodiment of the present invention, the solid-state battery is a sulfide solid-state battery.
[0016] Common complexing agents that are stable under alkaline conditions include sodium potassium tartrate, sodium tartrate, sodium citrate, ethylenediaminetetraacetic acid (EDTA), and glycine. However, copper-nickel alloys produced using electroplating solutions with sodium citrate, sodium tartrate, and glycine as complexing agents are not ideal. The sodium citrate system is substandard from the outset; even with changes to the complexing agent, the sodium citrate complexing agent breaks down during electroplating. Furthermore, the copper-nickel alloys plated using sodium tartrate and glycine systems have insufficient nickel content, thus these three complexing agents are excluded. Ultimately, sodium potassium tartrate and EDTA are identified as the two most suitable complexing agents.
[0017] This invention achieves the electrochemical electrolytic preparation of nickel-iron alloys by introducing organic complexes, a circulating electrolytic cell, and a DC power supply. Since the standard electrode potential of copper is 0.337V and that of nickel is -0.25V, copper's potential is approximately 0.6V higher than nickel's. The deposition potentials of the two co-deposited metals must be very close. If the difference is too large, the metal with the more positive potential will be preferentially deposited, and may even completely repel the deposition of the metal with the more negative potential, thus preventing the formation of an alloy coating. Therefore, by adding a complexing agent to balance the electrode potentials of the metal ions, the preparation of copper-nickel alloys is achieved.
[0018] This invention provides an alternative formulation system for the preparation of copper-nickel alloys using electrochemical electrolysis technology. Under normal pressure, electrochemical electrolysis can grow a thicker, more uniform coating at a faster deposition rate, and the properties of the alloy can be adjusted by modifying the electrolyte composition, current density, and pH.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] (1) The present invention adjusts the composition and thickness of the alloy by changing the concentration of metal ions and the amount of complexing agent, and by changing the process parameters (pH, current density, electrodeposition time, etc.), and can prepare a copper-nickel alloy with a tensile strength of 1012.70 MPa, an elongation of 5.27%, and a nickel content of 8.93%.
[0021] (2) Compared with alloys prepared by physical methods, the process of preparing alloys by electrodeposition is simple and the cost is low. The electrodeposited products have low impurity content and the overall microstructure of the alloy is a flat and dense morphology with large spherical particles evenly distributed. It belongs to the category of nanocrystals, has excellent corrosion resistance, and the coating thickness is uniform. Electrodeposition can be carried out at room temperature, saving energy and suitable for large-scale industrial production. It is an alloy preparation technology with broad application prospects. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a process flow diagram of Example 1;
[0024] Figure 2 In the figure, (a), (b) and (c) are the effects of potassium pyrophosphate concentration, current density and pH on the tensile strength of copper-nickel alloy in Example 1, respectively.
[0025] Figure 3 The image shows a SEM image of the copper-nickel alloy obtained in Example 1 when the potassium pyrophosphate concentration was 340.00 g / L.
[0026] Figure 4 The current density in Example 1 is 5 A / dm. 2 SEM image of the obtained copper-nickel alloy;
[0027] Figure 5 The image shows a SEM image of the copper-nickel alloy obtained when the electroplating solution pH was 8.5 in Example 1.
[0028] Figure 6 The graph shows the effect of potassium sodium tartrate auxiliary complexing agent concentration on the tensile strength of copper-nickel alloy in Example 2.
[0029] Figure 7 The image shows a SEM image of the copper-nickel alloy obtained in Example 2 when the concentration of potassium sodium tartrate was 60.00 g / L.
[0030] Figure 8 This is a graph showing the effect of EDTA-assisted complexing agent concentration on the tensile strength of copper-nickel alloy in Example 3;
[0031] Figure 9 The image shows a SEM image of the copper-nickel alloy obtained in Example 3 when the EDTA concentration was 6.0 g / L.
[0032] Figure 10 The image shows the XRD pattern of the copper-nickel alloy obtained in Example 3 when the EDTA concentration was 6.0 g / L. Detailed Implementation
[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.
[0034] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0035] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0036] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0037] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0038] The raw materials used in the following examples are all commercially available and conventional, and are not particularly limited. They will not be described again below.
[0039] Example 1
[0040] In this embodiment, nickel-copper alloy is prepared by electrodeposition, with copper electroplating on a rotating cathode titanium roller as the negative electrode, and an oxygen-evolving copper plate and a nickel plate as the positive electrode, and an aqueous pyrophosphate solution as the electrolyte.
[0041] (1) The concentrations of copper pyrophosphate, nickel chloride, and sodium saccharin in the electrolyte were controlled at 20 g / L, 40 g / L, and 2 g / L, respectively. The concentrations of potassium pyrophosphate were adjusted to 320, 330, 340, 350, 360, 370, and 380 g / L, respectively. The pH of the electrolyte was 8.5. The effect of potassium pyrophosphate concentration on the properties of the resulting copper-nickel alloy was studied. During the electroplating process, the current density was 5 A / dm³. 2 The electroplating temperature was 50℃, the electrolyte circulation rate was 700mL / min, the distance between the positive and negative electrodes was 3cm, and the electrodeposition time was 20min to prepare a copper-nickel alloy.
[0042] Figure 1 This is a process flow diagram for this embodiment.
[0043] The results showed that as the potassium pyrophosphate concentration increased from 320.00 g / L to 340.00 g / L, the tensile strength increased from 818.69 MPa to 913.02 MPa; however, with further increases in potassium pyrophosphate concentration, the tensile strength began to decrease, and the overall curve showed a pattern of first increasing significantly and then decreasing, as shown in the figure. Figure 2 As shown in Figure (a), potassium pyrophosphate reaches its maximum at 340.00 g / L, with an elongation of 3.97%. Figure 3 This is a SEM image of the copper-nickel alloy obtained in this embodiment when the potassium pyrophosphate concentration is 340.00 g / L.
[0044] (2) The electrolyte was controlled to contain 20 g / L copper pyrophosphate, 40 g / L nickel chloride, 2 g / L sodium saccharin, and 340 g / L potassium pyrophosphate, with a pH of 8.5. During electroplating, the electroplating temperature was 50℃, the electrolyte circulation rate was 700 mL / min, the electrode spacing was 3 cm, and the electroplating current densities were set to 3, 5, 7, 9, and 11 A / dm³, respectively. 2 Electrodeposition times were set at 25, 20, 18, 14, and 10 min to investigate the effects of different electroplating current densities on the surface roughness and microstructure of the coating.
[0045] The results are as follows Figure 2 As shown in Figure (b): when the current density is 3 A / dm 2 At this point, the alloy coating has large grain size and a porous surface, resulting in a minimum tensile strength of 850.40 MPa and an elongation of 3.97%. When the current density is 5 A / dm³, the tensile strength is also low. 2 At that time, the average grain size of the coating decreased, the gap between the crystals was smaller, and the density was higher, which increased the tensile strength of the alloy coating to 975.70 MPa and the elongation to 4.13%. However, as the current density increased, the tensile properties decreased again. Figure 4 In this embodiment, the current density is 5 A / dm. 2 The SEM image of the resulting copper-nickel alloy.
[0046] (3) The electrolyte concentrations were controlled as follows: copper pyrophosphate 20 g / L, nickel chloride 40 g / L, sodium saccharin 2 g / L, potassium pyrophosphate 340 g / L, and current density 5 A / dm³. 2 The pH values of the electrolyte were adjusted to 8, 8.5, 9, 9.5, and 10 to investigate the effect of electrolyte pH on the properties of the obtained copper-nickel alloy. During the electroplating process, the plating temperature was 50℃, the electrolyte circulation rate was 700 mL / min, the electrode spacing was 3 cm, and the electrodeposition time was 20 min to prepare the copper-nickel alloy.
[0047] The results are as follows Figure 2As shown in Figure (c): when the pH of the electroplating solution is 8.0, the tensile strength is the lowest at 791.58 MPa, with an elongation of 4.60%. When the pH is further increased to 8.5, the tensile strength of the alloy coating gradually increases to 954.99 MPa, reaching its maximum value, with an elongation of 3.96%. Further increasing the pH of the alkaline plating solution results in a decrease in tensile strength with increasing pH. Figure 5 This is a SEM image of the copper-nickel alloy obtained when the electroplating solution pH is 8.5 in this embodiment.
[0048] Based on the above experimental data, when the potassium pyrophosphate concentration is 340.00 g / L, the electrolyte pH is 8.5, and the current density is 5 A / dm³, the optimal concentration is [missing information]. 2 The prepared copper-nickel alloy exhibited the best coating performance, with a uniform coating and low impurity content. The tensile strength reached 975.70 MPa, and the elongation was 3.97%. ICP-MS analysis revealed a nickel content of 6.66% in the copper-nickel alloy.
[0049] Example 2
[0050] Copper-nickel alloys were prepared by electrodeposition, with copper electroplating on a rotating cathode titanium roller as the negative electrode, and an oxygen-evolving copper plate and a nickel plate as the positive electrode, and an aqueous pyrophosphate solution as the electrolyte.
[0051] The electrolyte was controlled with copper pyrophosphate at 20 g / L, nickel chloride at 40 g / L, potassium pyrophosphate at 340.00 g / L, and sodium saccharin at 2 g / L. The concentrations of potassium sodium tartrate were adjusted to 60.0, 65.0, 70.0, 75.0, and 80.0 g / L, respectively, to study the effect of potassium sodium tartrate concentration on the properties of the obtained copper-nickel alloy.
[0052] At an electroplating current density of 5A / dm 2 Under the process conditions of electroplating temperature of 50℃, electroplating solution pH of 8.5, electrolyte circulation rate of 700mL / min, electrode spacing of positive and negative electrodes of 3cm, and electrodeposition for 20min, copper-nickel alloy was prepared.
[0053] Compared to Example 1, the difference lies in the addition of a potassium sodium tartrate complexing agent, and the result is as follows: Figure 6 As shown, the tensile strength of the copper-nickel alloy foil prepared in this embodiment generally showed a slow decreasing trend as the concentration of potassium sodium tartrate gradually increased to 80.00 g / L, reaching a maximum of 913.99 MPa at 60.00 g / L. It can be observed that excessively high potassium sodium tartrate concentrations lead to a decrease in the tensile strength of the alloy copper foil. ICP-MS analysis revealed that the nickel content of the copper-nickel alloy was 3.14%. Figure 7 This is a SEM image of the copper-nickel alloy obtained in this embodiment when the concentration of potassium sodium tartrate is 60.00 g / L.
[0054] Example 3
[0055] Copper-nickel alloys were prepared by electrodeposition, with copper electroplating on a rotating cathode titanium roller as the negative electrode, and an oxygen-evolving copper plate and a nickel plate as the positive electrode, and an aqueous pyrophosphate solution as the electrolyte.
[0056] The electrolyte was controlled with copper pyrophosphate at 20 g / L, nickel chloride at 40 g / L, potassium pyrophosphate at 340.00 g / L, and sodium saccharin at 2 g / L. The concentration of ethylenediaminetetraacetic acid (EDTA) was adjusted to 2.0, 4.0, 6.0, 8.0, and 10.0 g / L, respectively, to study the effect of EDTA concentration on the properties of the obtained copper-nickel alloy.
[0057] At an electroplating current density of 5A / dm 2 Under the process conditions of electroplating temperature of 50℃, electroplating solution pH of 8.5, electrolyte circulation rate of 700mL / min, electrode spacing of positive and negative electrodes of 3cm, and electrodeposition for 20min, copper-nickel alloy was prepared.
[0058] Compared to Example 2, the difference lies in the addition of an ethylenediaminetetraacetic acid (EDTA) complexing agent, using a composite complexing agent, and the results are as follows. Figure 8 As shown, the tensile strength of the copper-nickel alloy foil prepared in this embodiment generally showed an increasing trend followed by a slow decrease as the EDTA concentration gradually increased to 10.0 g / L. The maximum tensile strength of the copper-nickel alloy was achieved at 6.0 g / L, reaching 1012.70 MPa, with an elongation of 5.27%. This indicates that an appropriate amount of EDTA complexing agent is beneficial for improving the tensile strength of the copper-nickel alloy. ICP-MS analysis revealed that the nickel content of the copper-nickel alloy was 8.93%. Figure 9 This is a SEM image of the copper-nickel alloy obtained when the EDTA concentration was 6.0 g / L in this embodiment.
[0059] As can be seen from Examples 1 to 3 above, by controlling the electrolyte composition, adjusting the pH value and current density, copper-nickel alloys with different compositions, uniform coatings, dense grains, and low impurity content can be obtained.
[0060] Figure 10 The image shows the XRD pattern of the copper-nickel alloy obtained in Example 3 when the EDTA concentration was 6.0 g / L. As can be seen from the image, the peaks of the sample are all between the peaks of copper and nickel in the standard chart. Therefore, it can be concluded that the synthesized sample is a copper-nickel alloy.
[0061] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A method for preparing copper-nickel alloy for solid-state batteries using an alkaline system, characterized in that, A copper-nickel alloy is prepared by electrodeposition using a pyrophosphate aqueous solution system as the electrolyte. The pyrophosphate aqueous solution system includes the following components: raw materials copper pyrophosphate and nickel chloride, main complexing agent potassium pyrophosphate, auxiliary complexing agent ethylenediaminetetraacetic acid or potassium sodium tartrate, and also includes brighteners and additives.
2. The method for preparing copper-nickel alloy for solid-state batteries using an alkaline system according to claim 1, characterized in that, The brightener includes sodium saccharin, and the additives include 2-mercaptobenzimidazole and 2-mercaptobenzothiazole; in the pyrophosphate aqueous solution system, the concentrations of each component are as follows: copper pyrophosphate 10-20 g / L, nickel chloride 20-40 g / L, sodium saccharin 2-5 g / L, potassium pyrophosphate 320-380 g / L, 2-mercaptobenzimidazole 2-4 mg / L, 2-mercaptobenzothiazole 3-5 mg / L, and auxiliary complexing agent ethylenediaminetetraacetic acid 2-10 g / L or potassium sodium tartrate 60-80 g / L.
3. The method for preparing copper-nickel alloy for solid-state batteries using an alkaline system according to claim 1, characterized in that, The electrolyte has a circulation rate of 500–800 mL / min and a pH value of 8–10.
4. The method for preparing copper-nickel alloy for solid-state batteries using an alkaline system according to claim 1, characterized in that, When preparing copper-nickel alloys by electrodeposition, a rotating cathode titanium roller is used as the copper plating cathode, and an oxygen-evolving copper plate and a nickel plate are used as the anode, with a distance of 1 to 4 cm between the positive and negative electrodes.
5. The method for preparing copper-nickel alloy for solid-state batteries using an alkaline system according to claim 1, characterized in that, When preparing copper-nickel alloys by electrodeposition, the current density is 3.0–11.0 A / dm³. 2 The electrolyte temperature is 50–55℃, and the electrodeposition time is 10–25 min.
6. The method for preparing copper-nickel alloy for solid-state batteries using an alkaline system according to claim 5, characterized in that, The copper-nickel alloy used in solid-state batteries has a thickness of 4.5–18 μm, a nickel content of 3.14–8.93 wt%, and a tensile strength >1000 MPa.
7. A copper-nickel alloy prepared by a method for preparing a copper-nickel alloy for solid-state batteries using an alkaline system according to any one of claims 1 to 6.
8. The application of the copper-nickel alloy according to claim 7 in the preparation of solid-state batteries.
9. A solid-state battery, characterized in that, The copper-nickel alloy described in claim 7 is used as the negative electrode current collector.