A method for preparing copper foil surface zinc oxide crystal face regulated electrodeposition and application

Abstract

The application discloses a kind of copper foil surface zinc oxide crystal face regulation electrodepositing preparation method and application, belong to functional material preparation technical field, this method with commercial copper foil as substrate, using constant potential intermittent electrodeposition process, by regulating the type of crystal face inducer, concentration and electrodeposition potential, temperature, can selectively prepare with ZnO (002) crystal face as main nanosheet staggered network structure, or with ZnO (101) crystal face as main nanocone, nanorod and flower-like microsphere structure.The application uses the above-mentioned one kind of copper foil surface zinc oxide crystal face regulation electrodepositing preparation method and application, preparation process is simple, condition is mild, crystal face regulation precision is high, the obtained zinc oxide modified copper foil current collector can provide abundant alkali metal nucleation site, homogenize current density distribution, effectively inhibit lithium / sodium / potassium dendrite growth, stabilize electrode / electrolyte interface, has wide application prospect in high safety, long life alkali metal battery field.

Description

Technical Field

[0001] This invention relates to the field of functional material preparation technology, and in particular to a method and application of zinc oxide crystal plane controlled electrodeposition preparation on copper foil surface. Background Technology

[0002] With the rapid development of portable electronic devices, electric vehicles, and large-scale energy storage power stations, there is an urgent need for rechargeable batteries with high energy density, long cycle life, and high safety. Alkali metal anodes such as lithium, sodium, and potassium possess extremely high theoretical specific capacities (lithium 3860 mAh / g, sodium 1166 mAh / g, potassium 685 mAh / g) and extremely low redox potentials, making them ideal anode materials for next-generation high-energy-density rechargeable batteries. However, alkali metal anodes inevitably experience dendrite growth during cycling. Dendrites piercing the separator can lead to internal short circuits, causing thermal runaway and even explosions. Simultaneously, interfacial side reactions between the alkali metal and the electrolyte continuously consume active materials and electrolyte, resulting in rapid capacity decay, severely limiting the practical application of alkali metal batteries.

[0003] As a crucial component of alkali metal anodes, current collectors not only facilitate electron conduction but also provide a reaction site for alkali metal deposition / dissolution. Modifying the surface of copper foil current collectors to construct an interface layer with specific structures and chemical properties is an effective strategy for controlling alkali metal deposition behavior, suppressing dendrite growth, and improving interface stability. Zinc oxide (ZnO), a typical wide-bandgap semiconductor material, possesses excellent chemical stability, good electronic conductivity, and affinity for alkali metals. Furthermore, ZnO with different crystal orientations exhibits different surface atomic arrangements, surface energies, and electronic states, allowing for precise control of interfacial charge transfer and metal ion deposition behavior through crystal plane engineering. This demonstrates significant application potential in the field of alkali metal battery current collector interface modification.

[0004] Currently, the main methods for preparing zinc oxide thin films include hydrothermal deposition, sol-gel deposition, vapor deposition, and electrochemical deposition. Hydrothermal deposition typically requires high temperature and pressure conditions, resulting in long reaction cycles, demanding equipment, and difficulty in achieving large-area uniform preparation. Sol-gel deposition requires subsequent high-temperature calcination, which can easily lead to oxidation and deformation of the copper foil substrate, and the adhesion between the film and the substrate is poor. Vapor deposition methods (such as magnetron sputtering and atomic layer deposition) can prepare high-quality ZnO thin films, but the equipment is expensive, the deposition rate is low, and the production cost is high, failing to meet the needs of large-scale industrial production. Electrochemical deposition has attracted widespread attention due to its simple process, mild conditions, low cost, and ease of large-area preparation. However, existing electrochemical deposition methods suffer from low precision in crystal orientation control and the inability to selectively prepare ZnO with specific crystal faces, making it difficult to fully utilize the interfacial control advantages of different ZnO crystal faces. This results in unstable dendrite suppression effects in the prepared ZnO-modified current collectors and limited improvement in battery cycle performance.

[0005] Therefore, providing a simple and controllable electrochemical deposition method that can selectively prepare ZnO modified layers with different crystal orientations on the surface of copper foil to improve the cycle stability and safety of alkali metal batteries is an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a method and application for preparing zinc oxide crystal plane-controlled electrodeposition on copper foil to solve the above-mentioned problems.

[0007] This invention provides a method for electrodeposition of zinc oxide crystal plane controlled on the surface of copper foil, comprising the following steps: S1. Substrate pretreatment: After cutting the copper foil, ultrasonically clean it with anhydrous ethanol and deionized water in sequence to remove surface oil and impurities, and then blow it dry for later use. S2. Electrolyte preparation: Using soluble zinc salt as the zinc source, add a crystal facet inducer and dissolve it in deionized water, stirring until completely dissolved to obtain the electrodeposition electrolyte; S3. Assembly of the three-electrode system: The pretreated copper foil is used as the working electrode, the inert metal is used as the counter electrode, and silver / silver chloride is used as the reference electrode. The electrode is placed in an electrolytic cell containing the electrolyte. S4. Constant potential intermittent electrodeposition: After heating the electrolytic cell to the target deposition temperature and holding it at that temperature for 20-40 minutes, intermittent electrodeposition is performed using constant potential mode. First, pre-deposit for 100-300 seconds, then pause the program and let it stand for 3-10 minutes. Keep the other parameters unchanged and continue deposition for 1000-2000 seconds. S5. Post-processing: After deposition, the electrode is removed, rinsed with deionized water to remove surface solution residue, dried by blowing dry the surface moisture of the deposited layer, and then vacuum dried to obtain a zinc oxide modified copper foil current collector with the target crystal orientation.

[0008] Preferably, the soluble zinc salt in step S2 is zinc nitrate, and the concentration of zinc nitrate in the electrolyte is 0.05–0.1 mol / L.

[0009] Preferably, the crystal plane inducer is selected from one or more of alkali metal halides and sodium citrate; the electrodeposition potential is -0.85 to -0.95V (vs. SCE), and the deposition temperature is 60 to 70℃, so as to prepare a zinc oxide modified layer with ZnO(002) (i.e. ZnO-002) crystal plane as the main component.

[0010] Preferably, the concentration of the alkali metal halide in the electrolyte is 0.05–0.15 mol / L, and the concentration of the sodium citrate in the electrolyte is 0.05–0.15 mol / L.

[0011] Preferably, the crystal plane inducer is selected from one or more of ethylenediamine and hexadecyltrimethylammonium bromide; the electrodeposition potential is -1.05 to -1.15V (vs. SCE), and the deposition temperature is 65 to 75℃, so as to prepare a zinc oxide modified layer with ZnO(101) (i.e. ZnO-101) crystal plane as the main component.

[0012] It should be noted that ZnO-101 and ZnO-002 in the claims correspond to ZnO(101) and ZnO(002) in the specification, only the notation is different.

[0013] Preferably, the concentration of ethylenediamine in the electrolyte is 0.01–0.07 mol / L, and the concentration of hexadecyltrimethylammonium bromide in the electrolyte is 0.01–0.02 mol / L.

[0014] Preferably, in step S1, the ultrasonic cleaning time for anhydrous ethanol and deionized water is 10-20 min each; in step S5, the deionized water rinsing time is 5-15 min, the vacuum drying temperature is 70-90℃, and the drying time is 4-8 h.

[0015] A zinc oxide modified copper foil current collector is provided, which is prepared by the above-mentioned zinc oxide crystal plane controlled electrodeposition method on the surface of copper foil. The zinc oxide modification layer of the zinc oxide modified copper foil current collector is mainly composed of ZnO(002) crystal plane or ZnO(101) crystal plane. The ZnO(002) crystal plane modification layer is a nanosheet interlaced network structure, and the ZnO(101) crystal plane modification layer is a nanocone / nanoring array structure.

[0016] The zinc oxide modified copper foil current collector prepared by the zinc oxide crystal plane controlled electrodeposition method described above is used as the negative electrode current collector of an alkali metal battery, including lithium metal batteries, sodium metal batteries, or potassium metal batteries.

[0017] Preferably, the alkali metal battery is an asymmetric button cell, a symmetric button cell, or a button full cell; the symmetric button cell is formed by first electroplating the corresponding alkali metal onto the surface of the zinc oxide-modified current collector to obtain a composite anode, and then assembling two of the composite anodes; the positive electrode of the button full cell is made of an organic positive electrode material.

[0018] Therefore, the present invention employs the above-described method for preparing zinc oxide crystal plane-controlled electrodeposition on copper foil and its application, which has the following beneficial effects: (1) Using a constant potential intermittent electrodeposition process under normal pressure and mild conditions, without the need for high temperature and high pressure equipment and complex post-processing, zinc oxide modification layers can be directly prepared in situ on the surface of commercial copper foil. The products have good consistency and high repeatability, which can meet the needs of large-scale industrial production. By synergistically controlling the type and concentration of crystal facet inducers and electrodeposition parameters, modification layers with ZnO(002) or ZnO(101) crystal facets can be precisely and selectively prepared, breaking through the bottleneck of low crystal facet control precision in existing methods.

[0019] (2) The prepared ZnO(002) nanosheet interlaced network and ZnO(101) nanocone / nanoring array have three-dimensional porous features, which can provide abundant alkali metal nucleation sites and effectively homogenize the current density on the electrode surface. At the same time, the unique electronic state structure of different crystal planes can regulate the interfacial charge transfer behavior, induce the directional and uniform deposition of metal ions, and synergistically suppress dendrite growth from both physical space and electronic state dimensions.

[0020] (3) The zinc oxide modification layer can induce uniform alkali metal deposition, fundamentally avoiding interfacial side reactions caused by dendrite growth and stabilizing the electrode / electrolyte interface. The alkali metal symmetric battery assembled based on it exhibits ultra-long cycle life and low voltage polarization. The full cell can still maintain excellent capacity retention at high discharge rates, effectively solving the dendrite safety hazards and rapid capacity decay problems of alkali metal batteries.

[0021] (4) This preparation method is applicable to commercial copper foil substrates. The prepared current collector can be widely used in various alkali metal battery systems such as lithium, sodium, and potassium. It has good application prospects in the fields of high safety and long life consumer electronics, electric vehicles and large-scale energy storage.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1This invention presents the morphology and crystal phase characterization of ZnO(002)@Cu samples prepared in Example 1 of the method for preparing zinc oxide crystal plane controlled electrodeposition on copper foil and its application. In this paper, a is the surface morphology of unmodified commercial copper foil; b is the surface morphology of the ZnO(002)@Cu sample prepared in Example 1; and c is the X-ray diffraction (XRD) pattern of the ZnO(002)@Cu sample prepared in Example 1. Figure 2 These are surface morphology images of ZnO(002)@Cu samples prepared under different crystal plane induction agent systems using a method for preparing zinc oxide crystal plane-controlled electrodeposition on copper foil according to the present invention. Specifically, a) is the surface morphology image of the 0.05 mol / L sodium citrate-induced ZnO(002)@Cu sample prepared in Example 2; b) is the surface morphology image of the 0.1 mol / L sodium citrate-induced ZnO(002)@Cu sample prepared in Example 3; c) is the surface morphology image of the 0.05 mol / L sodium chloride-induced ZnO(002)@Cu sample prepared in Example 4; and d) is the surface morphology image of the 0.1 mol / L sodium chloride-induced ZnO(002)@Cu sample prepared in Example 5. Figure 3 Figure 6 shows the morphological evolution and crystal phase characterization of ZnO(101)@Cu samples prepared in Example 6 of the present invention, which is a method for preparing ZnO(101)@Cu samples with controlled zinc oxide crystal plane on copper foil surface. Figure 6 shows the surface morphology of unmodified commercial copper foil; Figure 7 shows the surface morphology of ZnO(101)@Cu samples after a deposition time of 600 s; Figure 8 shows the surface morphology of ZnO(101)@Cu samples after a deposition time of 1200 s; Figure 9 shows the surface morphology of ZnO(101)@Cu samples after a deposition time of 1800 s; Figure 10 shows a magnified view of the dashed area in Figure 10; and Figure 11 shows the X-ray diffraction (XRD) pattern of the ZnO(101)@Cu samples prepared in Example 6. Figure 4 Figure 1 shows the surface morphology of ZnO(101)@Cu samples prepared under different additive systems in the copper foil surface zinc oxide crystal plane controlled electrodeposition method of the present invention. Figure 2 shows the surface morphology of the 0.065 mol / L ethylenediamine-induced ZnO(101)@Cu sample prepared in Example 8; Figure 3 shows a magnified view of the dashed area in Figure 2; Figure 4 shows the surface morphology of the 0.013 mol / L ethylenediamine high-zinc salt-induced ZnO(101)@Cu sample prepared in Example 7; Figure 5 shows a magnified view of the dashed area in Figure 5; Figure 6 shows the surface morphology of the hexadecyltrimethylammonium bromide-induced ZnO(101)@Cu sample prepared in Example 9; Figure 7 shows a magnified view of the dashed area in Figure 7. Detailed Implementation

[0024] To better understand the above technical solutions, a detailed description of the solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0026] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0027] Example 1 The preparation of ZnO(002) crystal plane modified copper foil current collector induced by 0.1 mol / L potassium chloride is as follows: Substrate pretreatment: Cut commercial copper foil to a suitable size, and ultrasonically clean it for 15 minutes in sequence with anhydrous ethanol and deionized water to remove surface oil and impurities. Then dry it for later use.

[0028] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and potassium chloride is used as a crystal face inducing agent. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.1 mol / L potassium chloride. The solution is then magnetically stirred until completely dissolved.

[0029] Three-electrode system assembly: using pretreated copper foil as the working electrode, platinum sheet as the inert metal counter electrode, and silver / silver chloride as the reference electrode, and placing it in an electrolytic cell containing the above electrolyte.

[0030] Constant potential intermittent electrodeposition: After heating the electrolytic cell to 65℃ and holding it at that temperature for 30 min, intermittent electrodeposition was performed using constant potential mode. First, pre-deposit for 200 s, pause the program and let it stand for 5 min, keeping other parameters unchanged, and then continue deposition for 1600 s, with a deposition potential of -0.9V.

[0031] Post-processing: After deposition, the electrode was removed and rinsed continuously with deionized water for 10 minutes to remove surface solution residue. After drying the surface moisture of the deposited layer with a rubber bulb, it was placed in a vacuum oven and dried at 80°C for 6 hours to obtain zinc oxide modified copper foil current collector.

[0032] Conclusion: The sample obtained in this embodiment is as follows Figure 1 As shown in b and c. XRD pattern confirmed the formation of hexagonal wurtzite structure zinc oxide (JCPDS No. 36-1451), with (002) crystal plane being the absolute dominant crystal plane; the surface morphology is a uniform and dense nanosheet interwoven network structure, with nanosheets overlapping to form a three-dimensional porous framework, which has good adhesion to the copper foil substrate and no shedding phenomenon.

[0033] Example 2 The ZnO(002) crystal plane modified copper foil current collector was prepared by induction with 0.05 mol / L sodium citrate. The specific steps are as follows: Substrate pretreatment: Same as in Example 1.

[0034] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and sodium citrate is used as a crystal face inducing agent. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.05 mol / L sodium citrate. The solution is then magnetically stirred until completely dissolved.

[0035] Three-electrode system assembly: Same as in Example 1.

[0036] Constant potential intermittent electrodeposition: Same as in Example 1.

[0037] Post-processing: Same as in Example 1.

[0038] Conclusion: The sample obtained in this embodiment is as follows Figure 2 As shown in a. The XRD results show that the (002) crystal plane is the dominant crystal plane; the surface morphology is a thin sheet-like nanosheet interlaced network, the nanosheet thickness is about 20-30 nm, the edges are clear, the pores are uniformly distributed, and the three-dimensional network structure is well developed.

[0039] Example 3 The ZnO(002) crystal plane modified copper foil current collector was prepared by induction with 0.1 mol / L sodium citrate. The specific steps are as follows: Substrate pretreatment: Same as in Example 1.

[0040] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and sodium citrate is used as a crystal face inducing agent. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.1 mol / L sodium citrate. The solution is then magnetically stirred until completely dissolved.

[0041] Three-electrode system assembly: Same as in Example 1.

[0042] Constant potential intermittent electrodeposition: Same as in Example 1.

[0043] Post-processing: Same as in Example 1.

[0044] Conclusion: The sample obtained in this embodiment is as follows Figure 2 As shown in b in Example 2, the thickness of the nanosheets increased to 40-50 nm, the stacking was more compact, the surface roughness was moderate, and the complete three-dimensional interlaced network structure was still maintained, with no significant decrease in the orientation of the (002) crystal plane.

[0045] Example 4 The ZnO(002) crystal plane modified copper foil current collector was prepared by induction with 0.05 mol / L sodium chloride. The specific steps are as follows: Substrate pretreatment: Same as in Example 1.

[0046] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and sodium chloride is used as a crystal face inducing agent. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.05 mol / L sodium chloride. The solution is then magnetically stirred until completely dissolved.

[0047] Three-electrode system assembly: Same as in Example 1.

[0048] Constant potential intermittent electrodeposition: Same as in Example 1.

[0049] Post-processing: Same as in Example 1.

[0050] Conclusion: The sample obtained in this embodiment is as follows Figure 2 As shown in c in the figure. A zinc oxide modified layer with (002) crystal plane as the main structure was successfully prepared. The surface morphology is an irregular nanosheet interlaced structure with good overall coverage.

[0051] Example 5 The ZnO(002) crystal plane modified copper foil current collector was prepared by induction with 0.1 mol / L sodium chloride. The specific steps are as follows: Substrate pretreatment: Same as in Example 1.

[0052] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and sodium chloride is used as a crystal face inducing agent. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.1 mol / L sodium chloride. The solution is then magnetically stirred until completely dissolved.

[0053] Three-electrode system assembly: Same as in Example 1.

[0054] Constant potential intermittent electrodeposition: Same as in Example 1.

[0055] Post-processing: Same as in Example 1.

[0056] Conclusion: The sample obtained in this embodiment is as follows Figure 2As shown in d in the figure. The nanosheets tend to be uniform in size, the stacking density is increased, the surface is smoother, the intensity of the characteristic diffraction peaks of the (002) crystal plane is significantly enhanced, and the orientation degree of the crystal plane is further improved.

[0057] Example 6 The preparation of ZnO(101) crystal plane modified copper foil current collector induced by 0.013 mol / L ethylenediamine low zinc salt is as follows: Substrate pretreatment: Same as in Example 1.

[0058] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and ethylenediamine is used as a crystal facet inducer. The two are dissolved in deionized water to prepare an aqueous solution containing 0.05 mol / L zinc nitrate and 0.013 mol / L ethylenediamine. The solution is then magnetically stirred until completely dissolved.

[0059] Three-electrode system assembly: Same as in Example 1.

[0060] Constant potential intermittent electrodeposition: After heating the electrolytic cell to 70℃ and holding it at that temperature for 30 min, intermittent electrodeposition was performed using constant potential mode. First, pre-deposit for 200 s, pause the program and let it stand for 5 min, keeping other parameters unchanged, and then continue deposition for 1600 s with a deposition potential of -1.1V.

[0061] Post-processing: Same as in Example 1.

[0062] Conclusion: The sample obtained in this embodiment is as follows Figure 3 As shown in d and f. XRD pattern confirms the formation of hexagonal wurtzite structure zinc oxide, with (101) crystal plane being the absolute dominant crystal plane; the surface morphology is a flower-like nanorod array, with nanorods growing vertically from the copper foil surface, the top of which is conical and forked, the overall arrangement is uniform, and the array height is consistent.

[0063] Example 7 The preparation of ZnO(101) crystal plane modified copper foil current collector induced by 0.013 mol / L ethylenediamine high zinc salt is as follows: Substrate pretreatment: Same as in Example 1.

[0064] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and ethylenediamine is used as a crystal facet inducer. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.013 mol / L ethylenediamine. The solution is then magnetically stirred until completely dissolved.

[0065] Three-electrode system assembly: Same as in Example 1.

[0066] Constant potential intermittent electrodeposition: Same as in Example 6.

[0067] Post-processing: Same as in Example 1.

[0068] Conclusion: The sample obtained in this embodiment is as follows Figure 4 As shown in b and b1 in Example 6, the zinc oxide growth rate is faster, the morphology changes to an independent nanocone structure with good vertical orientation and no obvious aggregation.

[0069] Example 8 The ZnO(101) crystal plane modified copper foil current collector was prepared by induction with 0.065 mol / L ethylenediamine. The specific steps are as follows: Substrate pretreatment: Same as in Example 1.

[0070] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and ethylenediamine is used as a crystal facet inducer. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.065 mol / L ethylenediamine. The solution is then magnetically stirred until completely dissolved.

[0071] Three-electrode system assembly: Same as in Example 1.

[0072] Constant potential intermittent electrodeposition: Same as in Example 6.

[0073] Post-processing: Same as in Example 1.

[0074] Conclusion: The sample obtained in this embodiment is as follows Figure 4 As shown in a and a1 in the figure. The morphology further evolved into a short and thick nanorod structure with a smooth surface and a tight arrangement. The characteristic diffraction peak intensity of the (101) crystal plane remained at a high level.

[0075] Example 9 The specific steps for preparing ZnO(101) crystal plane modified copper foil current collectors induced by hexadecyltrimethylammonium bromide are as follows: Substrate pretreatment: Same as in Example 1.

[0076] Electrolyte preparation: Zinc nitrate is used as a soluble zinc salt, and hexadecyltrimethylammonium bromide is used as a crystal face inducing agent. The two are dissolved in deionized water to prepare an aqueous solution containing 0.1 mol / L zinc nitrate and 0.013 mol / L hexadecyltrimethylammonium bromide. The solution is then magnetically stirred until completely dissolved.

[0077] Three-electrode system assembly: Same as in Example 1.

[0078] Constant potential intermittent electrodeposition: Same as in Example 6.

[0079] Post-processing: Same as in Example 1.

[0080] Conclusion: The sample obtained in this embodiment is as follows Figure 4 As shown in c and c1. A zinc oxide modified layer with (101) crystal plane as the main component was successfully prepared. The surface morphology is a flower-like microsphere structure assembled from nanosheets. It is composed of a large number of ultrathin nanosheets radially assembled and uniformly distributed on the surface of copper foil, and is firmly bonded to the copper foil substrate.

[0081] Example 10 Assembly and performance testing of potassium metal symmetric button cells; This embodiment uses the zinc oxide-modified copper foil current collector prepared in Example 1 to assemble a potassium metal symmetric button cell. The specific steps are as follows: Assemble an asymmetric button cell: Place a stainless steel gasket in the negative electrode shell, place potassium metal foil on the gasket, then place a glass fiber separator, add 1 mol / L potassium difluorosulfonamide electrolyte, place the zinc oxide modified copper foil current collector prepared in Example 1 on top of the separator, with one side of the zinc oxide modified layer in contact with the separator, then add the gasket, spring, and positive electrode shell in sequence, and encapsulate the asymmetric button cell using a battery encapsulation machine.

[0082] Preparation of composite anode: The above-mentioned asymmetric button cell was subjected to an anode flow rate of 0.5 mA·cm⁻¹. -2 Electroplating current density 5mAh·cm -2 The potassium was then removed from the battery, and the potassium-plated composite anode was taken out.

[0083] Assemble a symmetrical button cell: Place a stainless steel gasket in the negative electrode shell, place a composite anode on the gasket with the potassium-plated side in contact with the separator, then place a glass fiber separator, add 1 mol / L potassium bis(fluorosulfonyl)imide electrolyte, place another composite anode on top of the separator with the potassium-plated side in contact with the separator, and then add the gasket, spring, and positive electrode shell in sequence. Use a battery packaging machine to encapsulate the potassium metal symmetrical button cell.

[0084] Conclusion: The battery obtained in this embodiment is effective at 0.2 mA·cm⁻¹. -2 Current density, 0.2 mAh·cm -2 Under the given areal capacity conditions, this symmetric cell can cycle stably for over 2000 hours, with voltage polarization consistently below 40mV and no significant voltage fluctuations during the cycle. In contrast, the symmetric cell using unmodified copper foil exhibits a sudden voltage spike and internal short circuit after approximately 150 hours of cycling. Disassembly and observation revealed no obvious dendrite growth on the surface of the zinc oxide-modified current collector, and the potassium deposition layer was smooth and uniform.

[0085] Example 11 Assembly and performance testing of potassium metal button cells; This embodiment uses the zinc oxide-modified copper foil current collector prepared in Example 1 to assemble a potassium metal button cell. The specific steps are as follows: Preparation of composite anode: Same as steps 1 and 2 in Example 10.

[0086] Assembling a button cell: Place a stainless steel gasket in the negative electrode shell, place the composite anode on the gasket, with the potassium-plated side in contact with the separator, then place the glass fiber separator, add 1 mol / L potassium difluorosulfonamide electrolyte, place the perylene dianhydride positive electrode sheet on top of the separator, with the coated side in contact with the separator, then add the gasket, spring sheet and positive electrode shell in sequence, and encapsulate using a battery encapsulation machine to obtain a potassium metal button cell.

[0087] Conclusion: The battery obtained in this embodiment can stably cycle for 660 cycles at a high discharge rate of 10C, and the discharge specific capacity still remains at 80 mAh·g after the cycle is completed. -1 However, the capacity of the full cell using unmodified copper foil decayed to less than 50% of its initial value after approximately 80 cycles. These results indicate that the zinc oxide-modified current collector prepared in this invention can significantly improve the high-rate cycling stability of alkali metal batteries.

[0088] Therefore, this invention employs the aforementioned method and application for the electrodeposition of zinc oxide crystal plane control on copper foil surfaces. Using a constant potential intermittent electrodeposition process, the in-situ preparation of the ZnO modified layer can be completed under mild conditions of ambient pressure and 65–70°C, eliminating the need for high-temperature, high-pressure equipment and complex post-processing steps. Standardized copper foil pretreatment, electrolyte preparation, and electrodeposition procedures ensure product repeatability and consistency. Furthermore, this method allows for large-area continuous deposition directly on commercial copper foil surfaces, resulting in low production costs and meeting the needs of large-scale industrial production. In addition, the intermittent deposition mode of "pre-deposition 200s - resting 5min - continued deposition 1600s" effectively alleviates concentration polarization during electrodeposition, enabling uniform nucleation and growth of ZnO grains and avoiding problems such as rough deposition layers and uneven grain size caused by continuous deposition.

[0089] By selecting different types of crystal facet inducers and adjusting their concentrations, combined with the optimization of electrodeposition potential and temperature, precise controllability of ZnO crystal facet orientation was achieved: when potassium chloride, sodium citrate, etc., are used as crystal facet inducers, a nanosheet interlaced network structure dominated by ZnO(002) crystal facets can be prepared at a deposition potential of -0.9V (vs. SCE) and a deposition temperature of 65℃; when ethylenediamine, hexadecyltrimethylammonium bromide, etc., are used as crystal facet inducers, a nanocone / nanorrod array structure dominated by ZnO(101) crystal facets can be prepared at a deposition potential of -1.1V (vs. SCE) and a deposition temperature of 65-70℃. These two modification layers with different crystal facets and microstructures can achieve optimal interface control effects to meet the needs of different alkali metal battery systems.

[0090] The prepared ZnO-modified layer synergistically suppresses alkali metal dendrite growth from two dimensions: "physical spatial regulation" and "electronic state regulation." On the one hand, the interlaced network of ZnO(002) nanosheets and the array of ZnO(101) nanocones / nanorobars possess three-dimensional porous characteristics, providing abundant alkali metal nucleation sites and effectively homogenizing the current density distribution on the electrode surface, thus avoiding preferential dendrite nucleation and growth caused by local current concentration. On the other hand, the unique electronic state structure of ZnO with different crystal planes can regulate the interfacial charge transfer behavior, inducing directional and uniform deposition of alkali metal ions, further suppressing dendrite formation and extension at the electronic level. In addition, the dense and well-bonded ZnO-modified layer can induce uniform alkali metal deposition, thereby avoiding interfacial side reactions caused by dendrite growth, stabilizing the electrode / electrolyte interface, reducing interfacial impedance, and fundamentally solving the safety hazards of alkali metal batteries.

[0091] The ZnO-modified copper foil current collector used in the alkali metal anode exhibits excellent electrochemical performance. Taking a potassium metal battery as an example, the assembled symmetrical cell achieves ultra-long stable cycling at high current density without significant voltage polarization or dendrite growth. The assembled perylene tetracarboxylic dianhydride (PTCDA) cathode full cell maintains stable discharge capacity at a high discharge rate of 10C, with a cycle life several times longer than that of the unmodified copper foil current collector. Furthermore, this current collector has good versatility and is suitable for various alkali metal battery systems such as lithium, sodium, and potassium, comprehensively improving the electrochemical performance of different alkali metal battery systems.

[0092] The prepared ZnO-modified copper foil current collector can be used not only in laboratory research systems such as asymmetric button cells, symmetric button cells, and button full cells, but also in industrial battery systems such as pouch cells and cylindrical cells. It has broad application prospects and important commercial value in fields such as high-safety, long-life, and high-rate consumer electronics, electric vehicles, and large-scale energy storage.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for electrodeposition of zinc oxide crystal plane controlled on the surface of copper foil, characterized in that, Includes the following steps: S1. Substrate pretreatment: After cutting the copper foil, ultrasonically clean it with anhydrous ethanol and deionized water in sequence to remove surface oil and impurities, and then blow it dry for later use. S2. Electrolyte preparation: Using soluble zinc salt as the zinc source, add a crystal facet inducer and dissolve it in deionized water, stirring until completely dissolved to obtain the electrodeposition electrolyte; S3. Assembly of the three-electrode system: The pretreated copper foil is used as the working electrode, the inert metal is used as the counter electrode, and silver / silver chloride is used as the reference electrode. The system is placed in an electrolytic cell containing electrolyte. S4. Constant potential intermittent electrodeposition: After heating the electrolytic cell to 60-75℃ and holding it at that temperature for 20-40 minutes, intermittent electrodeposition is performed using constant potential mode. First, pre-deposit for 100-300 seconds, pause the program and let it stand for 3-10 minutes, and then continue to deposit for 1000-2000 seconds. S5. Post-processing: After deposition, the electrode is removed, rinsed with deionized water to remove surface solution residue, dried by blowing dry the surface moisture of the deposited layer, and then vacuum dried to obtain a zinc oxide modified copper foil current collector with the target crystal orientation. The crystal plane inducer is selected from one or more of alkali metal halides and sodium citrate; the electrodeposition potential is -0.85 to -0.95 V vs. SCE, and the deposition temperature is 60 to 70 °C. A zinc oxide modified layer with ZnO-002 crystal plane as the main component is prepared, and the surface morphology is a uniform and dense nanosheet interlaced network structure.

2. The method for preparing copper foil by zinc oxide crystal plane controlled electrodeposition according to claim 1, characterized in that, In step S2, the soluble zinc salt is zinc nitrate, and the concentration of zinc nitrate in the electrolyte is 0.05–0.1 mol / L.

3. The method for preparing copper foil by zinc oxide crystal plane controlled electrodeposition according to claim 1, characterized in that, The concentration of alkali metal halides in the electrolyte is 0.05–0.15 mol / L, and the concentration of sodium citrate in the electrolyte is 0.05–0.15 mol / L.

4. The method for preparing copper foil by zinc oxide crystal plane controlled electrodeposition according to claim 1, characterized in that, In step S1, the ultrasonic cleaning time for anhydrous ethanol and deionized water is 10-20 min each; in step S5, the rinsing time with deionized water is 5-15 min, the vacuum drying temperature is 70-90℃, and the drying time is 4-8 h.

5. A zinc oxide-modified copper foil current collector prepared by the zinc oxide crystal plane controlled electrodeposition method according to any one of claims 1-4, characterized in that, The zinc oxide modification layer of the zinc oxide-modified copper foil current collector is mainly composed of ZnO-002 crystal planes, in which the ZnO-002 crystal plane modification layer has a nanosheet interlaced network structure.

6. The application of the zinc oxide-modified copper foil current collector prepared by the zinc oxide crystal plane controlled electrodeposition method on the copper foil surface as described in claim 5, characterized in that, Used as a negative electrode current collector in alkali metal batteries, including lithium metal batteries, sodium metal batteries, or potassium metal batteries.

7. The application of the zinc oxide-modified copper foil current collector prepared by the zinc oxide crystal plane controlled electrodeposition method on the copper foil surface according to claim 6, characterized in that, Alkali metal batteries can be asymmetric button cells, symmetric button cells, or button full cells. Symmetric button cells are made by first electroplating the corresponding alkali metal onto the surface of a zinc oxide-modified current collector to obtain a composite anode, and then assembling two composite anodes. The positive electrode of a button full cell uses an organic positive electrode material.

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