Novel Ag-Cu composite solid solution phase material and preparation method and application thereof
The new Ag-Cu composite solid-solvent phase material prepared by ion implantation technology solves the shortcomings of traditional Ag-Cu alloys in high-performance requirements through the replacement of Ag atoms in the Cu lattice, and achieves the improvement of the strength, conductivity and thermal expansion performance of the material. It is suitable for high-performance applications in the modern electronic industry.
Patent Information
- Application Number
- CN202311550126.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-20
- Publication Date
- 2025-05-20
AI Technical Summary
Traditional Ag-Cu alloys have shortcomings in meeting the high-performance needs of modern electronics industry, especially in terms of strength, wear resistance and electrical conductivity.
The new Ag-Cu composite solid-solution phase material was prepared by ion implantation technology. The composite solid-solution phase was formed by the displacement of some Ag atoms in the Cu lattice and the presence of gap positions.
It has achieved improvements in the strength, hardness and conductivity of the material, has better resistance to deformation and wear, and can regulate the thermal expansion performance of the material, and is suitable for high-performance lithium battery electrodes.
Smart Images
Figure CN120020268A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of new energy materials, and particularly to a novel Ag-Cu composite solid solution phase material, a preparation method thereof, and an application thereof. Background Art
[0002] Research has found that almost all elements alloyed into the Cu matrix will inevitably deteriorate the excellent electrical conductivity of Cu. For example, Figure 1 as shown, among which the influence of Ag is the weakest. According to Figure 2 the Ag-Cu binary alloy phase diagram shown, at room temperature, Ag is almost insoluble in Cu, and at high temperature, the limit solid solubility of Ag in Cu is about 5% (atomic percentage, at.%). When the Ag content exceeds 5 at.%, the Cu-based Ag-Cu alloy system will have a primary solid solution phase and a secondary eutectic phase, and at this time, the system no longer belongs to a single solid solution phase. The additional phase interface will increase the electron scattering probability and thus rapidly reduce the electrical conductivity.
[0003] However, with the rapid development of modern electronic industries and technologies, Ag-Cu alloys have become a high-strength and high-conductivity conductor material with increasingly wide applications, ranging from being used as electrical contact materials for high-speed trains and lead frames for integrated circuits to being used in electrochemical catalytic processes at the atomic scale, etc. However, the Ag-Cu alloys prepared by traditional methods can no longer further meet the growing higher performance requirements of equipment / devices, etc. For example, with the further speed increase of high-speed trains, the electrical contact materials used therein need to be stronger, tougher, and more wear-resistant; the miniaturization and precision development of medical equipment require the wires / wire rods used therein to be more flexible and have higher electrical conductivity, etc. Therefore, it is very necessary to research and develop new Ag-Cu alloy phases that can meet higher performance requirements.
[0004] The traditional method for preparing the Ag-Cu solid solution phase is to directly alloy Cu and Ag, such as melting and solidifying, and then cooperate with post-treatment, such as annealing heat treatment, to obtain the required Ag-Cu alloy. However, due to the limitations of the equilibrium microstructure of the metal-metal type solid solution phase, the Ag-Cu alloys prepared by traditional methods can naturally only be a single type of substitutional solid solution phase, that is, a solid solution phase formed by Ag partially substituting Cu to occupy the lattice points of the Cu lattice (according to the rules). The solid solution strengthening effect caused by this substitutional solid solution in which Ag occupies a single site in the Cu lattice is weak, and the strength improvement brought about is also limited.
[0005] Theoretically, the rapid solidification of the melt (i.e., ultra-rapid quenching) technology is considered to have the potential to achieve interstitial solid solution in metals. This technical solution includes two important steps: First, the alloy melt impacts the surface of the cold matrix at a high speed so that the melt spreads into a thin layer; Second, during the solidification process, the melt thin layer always maintains good contact with the cold matrix. Although this technology is considered to have the potential to achieve metal-metal interstitial solid solution, however, after retrieval, it is found that only B.C. Giessen et al. reported that a large amount of interstitial solid solution of Cu in Y (not exceeding 15 at.%) was achieved in the Cu-Y (yttrium) system by using the ultra-rapid quenching method of the melt. But in their report, no information about the crystallization state of the obtained sample such as X-ray diffraction spectrum was given, so it cannot be excluded that the obtained sample is an amorphous sample, and there is currently no direct evidence that Cu is interstitially solid dissolved in Y. In addition, this technical solution requires a very high cooling rate (~10 8 ℃ s –1 ), which makes the prepared samples often only in the form of very thin (tens of micrometers level, generally not exceeding 50 μm) ribbons / sheets, so the sample size that this technical solution can handle is extremely limited. In addition, according to the published technical solution, the systems it can handle are also limited to the Cu-Y system. Summary of the Invention
[0006] The object of the present invention is to provide a novel Ag-Cu composite solid solution phase material, its preparation method and application, so as to realize a composite solid solution phase in which the material simultaneously has interstitial solid solution between Ag-Cu metals and substitutional solid solution of Ag-Cu.
[0007] To this end, in the first aspect, an embodiment of the present invention provides a novel Ag-Cu composite solid solution phase material. In the novel Ag-Cu composite solid solution phase material, the doped Ag atoms coexist in two ways: substitution and interstitial. Part of the Ag atoms are at the substitution sites of the Cu lattice, and part of the Ag atoms are at the interstitial sites of the Cu lattice, constituting the composite solid solution phase of Ag-Cu.
[0008] Preferably, in the novel Ag-Cu composite solid solution phase material, the mass percentage of Ag atoms accounts for 0.01%-0.1%.
[0009] Preferably, the novel Ag-Cu composite solid solution phase material is used for the lithium battery electrode; the impedance of the lithium battery electrode is reduced by the composite solid solution phase.
[0010] In the second aspect, an embodiment of the present invention provides an alloy material, and the alloy material includes the novel Ag-Cu composite solid solution phase material described in the first aspect above.
[0011] In a third aspect, an embodiment of the present invention provides a current collector for a lithium battery electrode, and the current collector for the lithium battery electrode includes the novel Ag-Cu composite solid solution phase material described in the first aspect above.
[0012] In a fourth aspect, an embodiment of the present invention provides a preparation method for the novel Ag-Cu composite solid solution phase material described in the first aspect above, including:
[0013] Placing a substrate material in the cavity of an ion implantation device and configuring a corresponding ion source target;
[0014] Bringing the cavity of the ion implantation device to a set vacuum degree;
[0015] Adjusting the implantation parameters to perform ion implantation; the implantation parameters include: suppression voltage, trigger voltage, cathode voltage, acceleration voltage, implantation dose.
[0016] Preferably, the substrate material is a Cu foil and the ion source target is an Ag target.
[0017] Preferably, the implantation dose is 10 15 -10 16 cm -2 , or, after implantation, the mass percentage of Ag atoms accounts for 0.01%-0.1% of the novel Ag-Cu composite solid solution phase material.
[0018] Preferably, the vacuum degree is below 10 –3 Pa.
[0019] Preferably, the suppression voltage is 0-400V; the trigger voltage of the Ag target is 5000V-8000V; the cathode voltage is 60V-130V; the acceleration voltage does not exceed 80kV.
[0020] For the novel Ag-Cu composite solid solution phase material provided by the embodiment of the present invention, by substituting some Ag atoms into the positions of the Cu lattice, a strengthening effect can be introduced to enhance the strength and hardness of the material, making the material more resistant to deformation and wear; the substitution and interstitial positions of Ag atoms in the Cu lattice will affect the thermal expansion coefficient of the material, and by controlling the process to adjust the distribution of Ag, the thermal expansion performance of the material can be regulated, which helps to slow down or avoid thermal stress and thermal fatigue caused by temperature changes; the doped Ag atoms can improve the electrical conductivity of Cu as an electrode current collector material through two ways of substitution and interstitial, reducing the impedance of the lithium battery electrode. In short, the Ag-Cu composite solid solution phase material can regulate the physical properties of the material through flexible atomic substitution and interstitial occupation methods, so as to meet the requirements of different engineering and application fields. Description of the Drawings
[0021] Figure 1 Schematic diagram of the electrical conductivity of the alloying of Cu with various elements;
[0022] Figure 2 Schematic diagram of the Ag-Cu binary alloy phase;
[0023] Figure 3 Schematic diagrams of two solid solution phases, namely substitutional solid solution and interstitial solid solution;
[0024] Figure 4 Flow chart of the preparation method of the embodiment of the present invention;
[0025] Figure 5 Schematic diagram of the microscopic atomic structure of the initial pure Cu phase;
[0026] Figure 6 Microscopic atomic structure of the Ag-Cu composite solid solution phase, where the red spheres represent Cu atoms and the white spheres represent Ag atoms;
[0027] Figure 7 Comparison chart of impedance performance when the initial pure Cu foil (Bare Cu) and the Ag-Cu composite solid solution phase (CSS) are used as current collectors;
[0028] Figure 8 Comparison chart of the Coulombic efficiency of the battery when the initial pure Cu foil (Bare Cu) and the Ag-Cu composite solid solution phase (CSS) are used as current collectors. Detailed implementation manners
[0029] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0030] To better understand the technical solutions of the present invention, the composite solid solution phase will be described first.
[0031] As a type of alloy phase, metal solid solutions can generally be divided into substitutional solid solution phases and interstitial solid solution phases according to the occupancy of solute atoms in the solvent lattice. In the substitutional solid solution phase, the solute occupies the lattice sites of the solvent, and in the interstitial solid solution phase, the solute is located in the interstitial positions of the solvent lattice. The two solid solution phases are shown in the schematic diagram. According to Figure 3 the rules, under equilibrium conditions, only substitutional solid solution phases can be formed between metals. Under equilibrium conditions, only substitutional solid solution phases can be formed between metals.
[0032] The embodiment of the present invention provides a novel Ag-Cu composite solid solution phase material. In the novel Ag-Cu composite solid solution phase material, the doped Ag atoms coexist in two ways, namely substitution and interstitial. Some Ag atoms are at the substitution sites of the Cu lattice, and some Ag atoms are at the interstitial sites of the Cu lattice, forming the Ag-Cu composite solid solution phase. Preferably, the mass percentage of Ag atoms is 0.01% - 0.1%.
[0033] As an alloy material, the novel Ag-Cu composite solid solution phase material of the present invention has many excellent properties. By partially replacing Ag atoms at the positions of the Cu lattice, a strengthening effect can be introduced, enhancing the strength and hardness of the material, making the material more resistant to deformation and wear; the replacement and interstitial positions of Ag atoms in the Cu lattice will affect the thermal expansion coefficient of the material. By controlling the distribution of Ag through process control, the thermal expansion performance of the material can be regulated, which helps to slow down or avoid thermal stress and thermal fatigue caused by temperature changes; the doped Ag atoms can improve the electrical conductivity of Cu as an electrode current collector material in two ways: replacement and interstitial. When the novel Ag-Cu composite solid solution phase material is used in a lithium battery electrode, the impedance of the lithium battery electrode can be reduced. The Ag-Cu composite solid solution phase material can regulate the physical properties of the material through flexible atomic replacement and interstitial occupation methods, so as to meet the needs of different engineering and application fields.
[0034] As described above, since only the substitution solid solution phase of Ag-Cu can be obtained under equilibrium conditions, in order to prepare a composite solid solution containing the Ag-Cu interstitial solid solution phase, a non-equilibrium technical solution must be adopted. The present invention realizes it by an implantation method.
[0035] In the specific implementation of this embodiment, the equipment used is an MT3-R2 type ion implanter (Beijing Borui Tiancheng Technology Co., Ltd.), but this does not limit that the technical solution of the present invention can only be realized by using this type of ion implanter. As long as the material is obtained by ion implantation, it is within the protection scope of the preparation method of the present invention.
[0036] As Figure 4 shown, the preparation method includes:
[0037] Step 110, placing the substrate material in the cavity of the ion implantation equipment and configuring the corresponding ion source target;
[0038] Among them, the substrate material is a Cu foil, and the ion source target is an Ag target. The substrate can be fixed to the sample holder in the cavity of the ion implantation equipment by conductive adhesive or directly placed.
[0039] Step 120, making the cavity of the ion implantation equipment reach the set vacuum degree;
[0040] Specifically, the vacuum degree is below 10 –3 Pa.
[0041] Step 130, adjusting the implantation parameters to perform ion implantation;
[0042] Specifically, the implantation dose is 10 15 -10 16 cm-2 Alternatively, after injection, the mass percentage of Ag atoms accounts for 0.01%-0.1% of the novel Ag-Cu composite solid solution phase material.
[0043] The injection parameters include: suppression voltage, trigger voltage, cathode voltage, acceleration voltage, and injection dose. In the equipment applied to this example, the suppression voltage is 0-400V; the trigger voltage of the Ag target is 5000V-8000V; the cathode voltage is 60V-130V; the acceleration voltage does not exceed 80kV.
[0044] Of course, under different equipment conditions, the parameters that can be set are also different. For example, in some injection equipment, the substrate can be heated, the vacuum requirements of some input equipment are different, and there may also be a certain inert gas environment, etc.
[0045] Of course, after ion injection, it may also include conventional cleaning and drying steps to obtain a clean material.
[0046] To more clearly illustrate the purpose and advantages of the present invention, the present invention will be further elaborated below in conjunction with embodiments. In addition, the embodiments described in the present invention are only partial embodiments. All other embodiments obtained by those skilled in the art without creative efforts based on the embodiments described in the present invention fall within the protection scope of the present invention. Additionally, it should be understood that these embodiments are only for more detailed description and should not be construed as limiting the present invention in any form, that is, it is not intended to limit the protection scope of the present invention.
[0047] Example 1
[0048] Prepare a commercially pure Cu foil with a thickness of about 40μm and a diameter of 10mm; the microscopic atomic structure of the initial pure Cu foil is as shown in the appendix Figure 5 As shown, the sample is in a polycrystalline single state, and grains with different orientations are clearly visible.
[0049] Prepare a pure Ag target and install it into the ion source of the ion injection equipment;
[0050] Fix the pure Cu foil to the sample holder of the ion injection equipment with conductive carbon glue, and evacuate the inside of the ion injection equipment cavity to 6×10 –4 Pa;
[0051] Perform ion injection, and set the injection parameters as follows: suppression voltage 200V; trigger voltage 6800V; cathode voltage 100V; acceleration voltage 50kV; Ag ion injection dose 7.95×10 15 cm –2 , and the mass percentage of the injected Ag in the novel Ag-Cu composite solid solution phase material is 0.01wt.%.
[0052] The initial pure Cu foil processed by the above method can form a Ag-Cu composite solid solution phase within a depth range of about 500 nm in its surface layer. The microscopic atomic structure of the composite solid solution phase presents the structural characteristics of a composite solid solution phase containing both interstitial solid solution and substitutional solid solution, as shown in Figure 6 The figure shows an atomic image of the composite solid solution phase sample taken by a spherical aberration corrected transmission electron microscope. Some Cu atoms (red spheres) and Ag atoms (silver spheres) are marked in the figure. It can be clearly seen that Ag atoms simultaneously occupy the substitutional sites and interstitial sites of the initial Cu foil lattice, forming Ag being compositely dissolved in Cu.
[0053] Example 2
[0054] Prepare a commercial pure Cu foil with a thickness of about 40 μm and a side length of 8 mm square;
[0055] Prepare a pure Ag target and install it in the ion source of the ion implantation equipment;
[0056] Fix the pure Cu foil to the sample holder of the ion implantation equipment with conductive carbon glue, and evacuate the inside of the ion implantation equipment cavity to 3×10 –4 Pa;
[0057] Perform ion implantation, and set the implantation parameters as follows: suppression voltage 300 V; trigger voltage 7000 V; cathode voltage 80 V; acceleration voltage 60 kV; Ag ion implantation dose 6×10 15 cm –2 , and the mass percentage of the implanted Ag in the new Ag-Cu composite solid solution phase material is 0.007 wt.%.
[0058] Example 3
[0059] Prepare a commercial pure Cu foil with a thickness of about 60 μm and a diameter of 10 mm;
[0060] Prepare a pure Ag target and install it in the ion source of the ion implantation equipment;
[0061] Fix the pure Cu foil to the sample holder of the ion implantation equipment with conductive carbon glue, and evacuate the inside of the ion implantation equipment cavity to 1×10 –4 Pa;
[0062] Perform ion implantation, and set the implantation parameters as follows: suppression voltage 150 V; trigger voltage 5000 V; cathode voltage 60 V; acceleration voltage 80 kV; Ag ion implantation dose 5×10 15 cm –2 , and the mass percentage of the implanted Ag in the new Ag-Cu composite solid solution phase material is 0.005 wt.%.
[0063] Taking the initial pure Cu foil used in Example 1 as the comparative sample, it is compared with the novel Ag-Cu composite solid solution phase material of Example 1 to study the impedance performance of the Ag-Cu composite solid solution phase prepared by the method shown in Example 1 and its application potential in modern lithium batteries.
[0064] The composite solid solution phase of Example 1 and the initial pure Cu foil of Comparative Example 1 are used as current collectors for lithium metal batteries, and an impedance spectrometer is used to test the impedance performance. The test results are as Figure 7 shown.
[0065] First of all, the impedance of the pure Cu foil current collector ( Figure 7 marked Bare Cu in Figure 7 ) is significantly higher than that of the composite solid solution phase current collector, and there are very significant fluctuations as the cycle progresses, indicating that the solid electrolyte interface phase (SEI) formed on its surface is unstable and repeatedly forms and decomposes as the battery cycles. This unstable SEI will consume the electrolyte and lithium source of the battery additionally, increase the impedance of the battery, reduce the battery performance and shorten the battery life. Compared with the pure Cu foil current collector, the impedance of the composite solid solution phase current collector (
[0066] marked CSS in Figure 7 ) decreases monotonically as the battery cycles and finally stabilizes, and is much smaller than that of the pure Cu foil current collector, indicating that a stable SEI is formed on the surface of the composite solid solution phase as the cycle progresses.
[0066] Batteries are assembled using the initial pure Cu foil and the composite solid solution phase of Example 1 (marked as CSS) as current collectors respectively. Li||CSS and Li||Cu button batteries are used for testing, where Li||Cu is used as the reference group. The electrolyte is 120 μL of 1 mol / L LiPF 6 ethylene carbonate / diethyl carbonate (EC / DMC volume ratio 1:1), and the separator is glass fiber. The test conditions for the Coulomb efficiency are a current density of 0.5 mA cm -2 , a deposition capacity of 1 mA h cm -2 , and a cut-off voltage of 1 V.
[0067] The Coulomb efficiency of the battery cycles is as Figure 8 shown. It can be found that the Coulomb efficiency of the batteries using the composite solid solution phase current collector is significantly higher than that of the batteries using the initial pure Cu foil current collector.
[0068] It can be seen therefrom that through the technical solution of the present invention, not only can metal interstitial solid solution be achieved, but also a composite solid solution phase with both solid solution characteristics can be obtained. The shape and size of the initial sample processed by the preparation method are not limited, and as long as the sample holder of a commercial ion implantation device can accommodate the sample, it can be processed. Compared with the prior art solutions, the technical solution of the present invention is easier to operate and has a wider applicability. The obtained composite solid solution phase can be used as a current collector of a lithium battery and has excellent performance, possessing commercial application value.
[0069] The specific embodiments described above have further elaborated on the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A novel Ag-Cu composite solid solution phase material, characterized in that: In the novel Ag-Cu composite solid solution phase material, doped Ag atoms coexist in both substitutional and interstitial modes, with some Ag atoms being located at substitutional sites of the Cu lattice and some Ag atoms being located at interstitial sites of the Cu lattice, thus forming an Ag-Cu composite solid solution phase.
2. The novel Ag-Cu composite solid solution phase material according to claim 1, characterized in that: In the novel Ag-Cu composite solid solution phase material, the mass percentage of Ag atoms is 0.01%-0.1%.
3. The novel Ag-Cu composite solid solution phase material according to claim 1, characterized in that: The novel Ag-Cu composite solid solution phase material is used for lithium battery electrodes; the composite solid solution phase is used to reduce the impedance of the lithium battery electrodes.
4. An alloy material, characterized in that: The alloy material comprises the novel Ag-Cu composite solid solution phase material as described in any one of claims 1 to 3.
5. A current collector for a lithium battery electrode, characterized in that: The current collector of the lithium battery electrode comprises the novel Ag-Cu composite solid solution phase material as described in any one of claims 1 to 3.
6. A method for preparing the novel Ag-Cu composite solid solution phase material according to any one of claims 1 to 3, characterized in that: The preparation method comprises: Placing the substrate material in the cavity of the ion implantation equipment and configuring the corresponding ion source target material; The chamber of the ion implantation equipment reaches a set vacuum degree; The implantation parameters are adjusted to perform ion implantation; the implantation parameters include: suppression voltage, trigger voltage, cathode voltage, acceleration voltage, and implantation dose.
7. The preparation method according to claim 6, characterized in that: The substrate material is Cu foil, and the ion source target material is Ag target.
8. The preparation method according to claim 7, characterized in that: The injection dose is 10 15 -10 16 cm -2 Alternatively, after implantation, the mass percentage of Ag atoms accounts for 0.01%-0.1% of the novel Ag-Cu composite solid solution phase material.
9. The preparation method according to claim 6, characterized in that: The vacuum degree is 10 –3 Below Pa.
10. The preparation method according to claim 6, characterized in that: The suppression voltage is 0-400V; the trigger voltage of the Ag target is 5000V-8000V; the cathode voltage is 60V-130V; and the acceleration voltage does not exceed 80kV.