Negative electrode current collector, preparation method thereof and lithium metal battery without negative electrode

Abstract

The invention discloses a negative current collector, a preparation method thereof and a negative-electrode-free lithium metal battery, and relates to the technical field of lithium batteries. The preparation method of the negative electrode current collector comprises the following steps: preparing a nickel salt solution; foamy copper is soaked in the nickel salt solution, and after soaking is completed, the foamy copper is taken out and subjected to cleaning and drying treatment in sequence; the dried foamy copper is placed in an argon atmosphere containing hydrogen to be subjected to heat treatment, nickel ions are diffused into a matrix of the foamy copper, and a nickel-doped layer is formed; the negative current collector provided by the invention is simple in preparation process, and the prepared negative current collector has the advantages of high coulombic efficiency and long cycle life.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a negative electrode current collector, a preparation method thereof, and a lithium metal battery without a negative electrode. Background Art

[0002] Since lithium-ion batteries were developed, they have developed extremely rapidly in many fields such as mobile phones, computers, cameras, and automobiles; for the growing demand in the future electric vehicle market, it is necessary to further develop lithium batteries with an energy density exceeding 500 Wh / kg. -1 The lithium metal battery without a negative electrode (AFLMB) can provide the maximum energy density for any given lithiated cathode system while reducing the battery production cost by eliminating the use of the initial negative electrode active material, showing great application potential.

[0003] However, the bottlenecks of poor cycle stability and low Coulomb efficiency of the lithium metal battery without a negative electrode seriously restrict its practical application. This is because copper and lithium metal can hardly form an alloy, and the uneven deposition / dissolution of lithium metal during the cycle leads to the problem of insufficient contact and difficult-to-solve battery polarization. Moreover, during the lithium deposition-stripping process, the negative electrode will undergo significant volume deformation, resulting in uneven electric field distribution, which induces dendrite growth and causes damage to the electrode structure. These factors jointly lead to the decline of the cycle performance and safety hazards of the lithium metal battery without a negative electrode. Therefore, it is necessary to modify the copper foil current collector to regulate the deposition / dissolution behavior of lithium during charge and discharge to improve the reversibility of the cycle. Summary of the Invention

[0004] The technical solution of the present invention provides a negative electrode current collector, a preparation method thereof, and a lithium metal battery without a negative electrode. The preparation process of the negative electrode current collector is simple, and it has the advantages of high Coulomb efficiency and long cycle life.

[0005] The negative electrode current collector provided by the present invention can be prepared by the following steps:

[0006] S1, Prepare a nickel salt solution;

[0007] S2, Immerse the copper foam in the nickel salt solution, and after immersion, take out the copper foam and perform cleaning and drying treatments in sequence;

[0008] S3, Place the dried copper foam in an argon atmosphere containing hydrogen for heat treatment to allow nickel ions to diffuse into the matrix of the copper foam and form a nickel-doped layer.

[0009] Optionally, the nickel salt solution includes at least one of nickel nitrate, nickel chloride, nickel sulfate, and nickel acetate.

[0010] Optionally, the nickel salt solution is a nickel nitrate solution;

[0011] The concentration of the nickel nitrate solution is 0.1 - 1 M.

[0012] Optionally, the nickel salt solution further contains a surfactant;

[0013] The surfactant includes at least one of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.

[0014] Optionally, the surfactant is sodium dodecyl sulfate, and the addition amount is 0.05 wt% - 0.5 wt%.

[0015] Optionally, in the step S2, the copper foam is immersed in the nickel salt solution for 10 - 20 h.

[0016] Optionally, in the step S3, in the argon atmosphere containing hydrogen, the content of hydrogen is 5%.

[0017] Optionally, in the step S3, the heat treatment temperature is 500 - 700 °C, the constant temperature is 2 - 6 h, and the heating rate is 4 - 6 °C / min.

[0018] The lithium metal battery without a negative electrode provided by the present invention includes a positive electrode, an electrolyte, a separator, and a negative electrode current collector prepared by the preparation method of the negative electrode current collector described above.

[0019] The present invention has the following beneficial effects:

[0020] The preparation process of the negative electrode current collector provided by the present invention is simple. By immersing the copper foam in the nickel salt solution, nickel salt adheres to the surface of the copper foam. Then, the copper foam is placed in an argon atmosphere containing hydrogen for heat treatment, so that the nickel salt is gradually decomposed, and nickel ions diffuse into the copper foam matrix to form a nickel-doped layer; after nickel atoms enter the copper lattice, the concentration of free electrons can be increased, the interfacial impedance can be reduced, thereby improving the conductivity of the material; nickel doping can reduce the lithium nucleation overpotential, induce uniform lithium deposition, and inhibit dendrites; nickel atoms can also serve as active sites to promote the occurrence of electrochemical reactions and improve the catalytic efficiency; at the same time, nickel doping can promote the formation of a porous structure on the surface of the copper foam, increase the specific surface area, provide more active sites, and further improve the electrochemical performance of the material; in addition, the nickel atomic radius is similar to that of copper, and the introduction of nickel atoms can reduce the defects of the copper lattice, improve the mechanical strength of the material, and buffer volume expansion; the negative electrode current collector prepared by the present invention has the advantages of high Coulomb efficiency and long cycle life. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Process flow schematic diagram of some embodiments of the method for preparing the negative electrode current collector of the present invention;

[0023] Figure 2 Negative electrode current collector prepared in Example 1 of the present invention and foam copper at a current density of 1 mA / cm 2 and a charge surface density of 1 mAh / cm 2 Coulomb efficiency diagram under test conditions;

[0024] Figure 3 Negative electrode current collector prepared in Example 1 of the present invention at a current density of 1 mA / cm 2 and a charge surface density of 1 mAh / cm 2 Voltage curve diagram under test conditions;

[0025] Figure 4 Voltage curve diagram of foam copper at a current density of 1 mA / cm 2 and a charge surface density of 1 mAh / cm 2 under test conditions;

[0026] Figure 5 Negative electrode current collector prepared in Example 1 of the present invention and foam copper at a current density of 1 mA / cm 2 and a charge surface density of 4 mAh / cm 2 Coulomb efficiency diagram under test conditions;

[0027] Figure 6 Voltage curve diagram of foam copper at a current density of 1 mA / cm 2 and a charge surface density of 4 mAh / cm 2 under test conditions;

[0028] Figure 7 Negative electrode current collector prepared in Example 1 of the present invention at a current density of 1 mA / cm 2 and a charge surface density of 4 mAh / cm 2 Voltage curve diagram under test conditions. Detailed implementation manners

[0029] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0030] Anode-free lithium metal battery (AFLMB) refers to a special lithium metal battery that does not contain active substances at the anode in its initial state. It uses a copper foil current collector as the anode, and the cathode is still composed of common lithium-containing metal materials (such as nickel cobalt manganese ternary lithium, lithium iron phosphate). Due to its advantages of high energy density and low manufacturing cost, the anode-free lithium metal battery shows great application potential in the field of energy storage.

[0031] The basic principle of the anode-free lithium metal battery is as follows: During the charging process, lithium ions combine with electrons on the surface of the copper foil current collector at the anode, and lithium deposition occurs: Li + +e - → Li (metallic lithium); during the discharging process, the lithium metal deposited on the copper foil current collector at the anode dissolves: Li - e - → Li + , and it returns to the cathode again, repeating this process; since there is no anode active material, the energy density of the AFLMB is greatly improved.

[0032] The research on modifying AFLMB mainly focuses on stabilizing the uniform deposition / dissolution of metallic lithium and effectively preserving active lithium, thereby improving the cycle stability and safety of the battery; the main modification methods include anode current collector modification, electrolyte optimization, electrolyte / anode interface layer (SEI) modification, prelithiation, etc.; among them, anode current collector modification is the most commonly used modification method at present, mainly including surface modification and structure modification.

[0033] In some prior arts, the copper foil can be immersed in silver nitrate solution by chemical immersion method to obtain a lithiumophilic Ag modification layer on its surface. The lithiumophilic Ag makes the deposition of lithium on the current collector more uniform. Although this method shows a higher Coulomb efficiency compared to bare copper, the long-cycle performance has not been improved; there are also prior arts that use a copper substrate as a template, add aldehyde compounds and phenolic compounds, and carry out a polymerization reaction in a mixed solution of ammonia water and ethanol to obtain a copper substrate coated with a carbon precursor. The obtained copper substrate coated with a carbon precursor is pyrolyzed in a reducing atmosphere to obtain a copper-based current collector modified with a three-dimensional lithiumophilic carbon interface, but the process is relatively cumbersome.

[0034] Embodiments of the present invention aim to provide a negative electrode current collector with a simple preparation process, high Coulombic efficiency, and long cycle life.

[0035] Referring to Figure 1 , in some embodiments, the negative electrode current collector provided by the present invention can be prepared through the following steps:

[0036] Step 1, first prepare copper foam (e.g., 300 μm), cut it into a suitable size (e.g., 3 cm × 3 cm), and place it in an HCl (or H2SO4, HNO3) solution with a concentration of 0.5 - 1.2 M for acid treatment for 5 - 15 min. The purpose is to remove the surface oxide layer and improve the adhesion and uniformity of nickel doping; after acid treatment, the copper foam is washed with deionized water, then wiped with acetone multiple times, and then ultrasonically cleaned in anhydrous ethanol for 10 - 20 min to remove the tiny impurities and dirt attached to the copper foam. Finally, it is washed with deionized water multiple times, wiped with lint-free paper to remove excess water stains, and then placed in a vacuum drying oven and dried at 40 °C for 10 - 20 h.

[0037] Step 2, prepare a nickel salt solution, which includes but is not limited to one or more of nickel nitrate, nickel chloride, nickel sulfate, and nickel acetate.

[0038] A surfactant can also be added to the nickel salt solution to improve the uniformity and stability of the solution, such as anionic surfactants like sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium oleate, cationic surfactants like cetyltrimethylammonium bromide and dodecyltrimethylammonium chloride, non-ionic surfactants like polyethylene glycol and Tween - 80, and amphoteric surfactants like lecithin and dodecyl betaine.

[0039] In some embodiments, nickel nitrate can be selected as the nickel salt. Dissolve nickel nitrate in an appropriate amount of deionized water or ethanol, stir evenly until completely dissolved to obtain a nickel nitrate solution with a concentration of 0.1 - 1.0 M; use sodium dodecyl sulfate (SDS, 0.05 wt% - 0.5 wt%) as a dispersant and add it to the nickel nitrate solution, which can provide good wettability and dispersibility, effectively prevent particle agglomeration, and improve the uniformity and stability of the solution; just add a few drops of the sodium dodecyl sulfate solution with a dropper.

[0040] Step 3, immerse the copper foam pretreated in Step 1 into the nickel salt solution prepared in Step 2, ensure that the copper foam is completely immersed, and soak it at room temperature for 10 - 20 h to allow the nickel salt to fully penetrate into the pores of the copper foam; after soaking, take out the copper foam and rinse it with deionized water to remove the excess nickel salt on the surface.

[0041] Step 4: Air-dry the impregnated copper foam at room temperature or dry it with hot air; then place it in a drying oven and dry it at 50-80°C for 2-4 hours to ensure complete drying; then put the treated copper foam in a porcelain boat and place it in a tubular furnace under an argon atmosphere (containing 5% H2) for heat treatment. During the heat treatment, the nickel salt decomposes, and nickel ions diffuse into the copper foam matrix to form a nickel-doped layer; before heat treatment, first pass argon at an appropriate flow rate at room temperature for 30 minutes; the heat treatment temperature is 500-700°C, hold for 2-6 hours, and the heating rate is 4-6°C / min; after the heat treatment is completed, take out the copper foam from the tubular furnace and cool it naturally to room temperature, and wipe its surface with anhydrous ethanol.

[0042] The preparation method of the negative electrode current collector provided by the embodiment of the present invention first performs a series of pretreatment on the copper foam (acid treatment, washing with anhydrous ethanol and deionized water), and then immerses it in a nickel nitrate solution with a suitable concentration for several hours, and at the same time adds a small amount of surfactant with a reasonable concentration to improve the uniformity and stability of the nickel salt solution; then put the pretreated copper foam into a tubular furnace filled with an argon atmosphere (containing 5% H2) for high-temperature heat treatment for a certain period of time; during the heat treatment, the nickel salt gradually decomposes, and nickel ions diffuse into the copper foam matrix to form a nickel-doped layer.

[0043] In the embodiment of the present invention, the nickel salt solution needs to be accurately prepared to ensure accurate concentration. Too high a concentration may lead to an overly thick nickel-doped layer, causing agglomeration of nickel and forming large particles, which will affect the electrochemical performance and mechanical properties. Too low a concentration will result in insufficient nickel doping; in the embodiment of the present invention, the heat treatment temperature and time also need to be accurately controlled to ensure doping uniformity and improve the electrochemical performance of the material.

[0044] In the embodiment of the present invention, by immersing the copper foam in the nickel salt solution, the nickel salt adheres to the surface of the copper foam. Then, the copper foam is placed in an argon atmosphere containing hydrogen for heat treatment, so that the nickel salt gradually decomposes, and nickel ions diffuse into the copper foam matrix to form a nickel-doped layer; after nickel atoms enter the copper lattice, the concentration of free electrons can be increased, the interface impedance can be reduced, thereby improving the electrical conductivity of the material; nickel doping can reduce the lithium nucleation overpotential, induce uniform lithium deposition, and inhibit dendrites; nickel atoms can also serve as active sites to promote the occurrence of electrochemical reactions and improve the catalytic efficiency; at the same time, nickel doping can promote the formation of a porous structure on the surface of the copper foam matrix, increase the specific surface area, provide more active sites, and further improve the electrochemical performance of the material; in addition, the nickel atomic radius is similar to that of copper, and the introduction of nickel atoms can reduce the defects of the copper lattice, improve the mechanical strength of the material, and buffer volume expansion.

[0045] The present invention also provides a lithium metal battery without a negative electrode, which includes a positive electrode, an electrolyte, a separator, and a negative electrode current collector. The negative electrode current collector is prepared by the preparation method provided in the above embodiments, and the positive electrode is still composed of common lithium-containing metal materials (such as lithium nickel cobalt manganese oxide, lithium iron phosphate, etc.).

[0046] The present invention also proposes the following specific embodiments to fully illustrate the implementation manner and beneficial effects of the technical solution of the present invention; the following specific embodiments are exemplary and do not constitute any form of limitation to the protection scope of the present invention.

[0047] Example 1

[0048] Step 1: First, prepare copper foam with a thickness of 300 μm, cut it into appropriate sizes, and place it in a 1M HCl solution for acid treatment for 10 min to remove the surface oxide layer. Then, wash it with deionized water, and then wipe it with acetone multiple times. Next, place it in absolute ethanol for ultrasonic cleaning treatment for 15 min. Finally, wash it with deionized water multiple times, wipe off the excess water stains with lint-free paper, and then place it in a vacuum drying oven for drying at 40 °C for 15 h.

[0049] Step 2: Prepare a nickel nitrate solution with a concentration of 1.0 M. Dissolve the nickel salt in an appropriate amount of deionized water or ethanol and stir evenly until it is completely dissolved. Add a small amount of 0.5 wt% sodium dodecyl sulfate (a few drops can be added with a dropper) to improve the uniformity and stability of the solution.

[0050] Step 3: Immerse the copper foam pretreated in Step 1 into the prepared nickel salt solution, ensure that the copper foam is completely immersed, and soak it at room temperature for 10 h to allow the nickel salt to fully penetrate into the pores of the copper foam; after soaking, take out the copper foam, rinse it with deionized water, and remove the excess nickel salt on the surface.

[0051] Step 4: Air-dry the impregnated copper foam at room temperature or dry it with a hot air blower; then place it in a drying oven and dry it at 50 °C for 4 h to ensure complete drying; then place the treated copper foam in a porcelain boat and perform heat treatment in a tubular furnace under an argon atmosphere (containing 5% H2). During the heat treatment process, the nickel salt decomposes, and nickel ions diffuse into the copper foam matrix to form a nickel-doped layer; the heat treatment temperature is 500 °C, keep the temperature constant for 6 h, and the heating rate is 4 °C / min. After the heat treatment is completed, take out the copper foam from the tubular furnace and naturally cool it to room temperature, and wipe its surface with absolute ethanol; first, pass argon at an appropriate flow rate at room temperature for 30 min before the heat treatment.

[0052] Figure 2 Shows the negative electrode current collector prepared in this embodiment at 1 mA / cm 2 (current density), 1 mAh / cm 2Coulombic efficiency under the condition of (surface charge density) and comparison results of Coulombic efficiency of copper foam at 1 mA / cm 2 and 1 mAh / cm 2 The comparison results of Coulombic efficiency under the conditions are shown. In the figure, Cu foam represents copper foam, and Ni@Cu foam represents the nickel-doped copper foam negative electrode current collector prepared in this example. It can be seen that as the number of cycles increases, the Coulombic efficiency of copper foam decreases significantly, while the Coulombic efficiency of the negative electrode current collector prepared in this example still maintains a relatively high value, indicating that the negative electrode current collector prepared in this example has the advantages of high Coulombic efficiency and long cycle life.

[0053] Figure 3 and Figure 4 respectively show the voltage curves of the negative electrode current collector prepared in this example and copper foam at different cycle numbers under the test conditions of 1 mA / cm 2 and 1 mAh / cm 2 It can be seen that the negative electrode current collector prepared in this example has excellent cycle stability.

[0054] Furthermore, the test was carried out by increasing the areal capacity. Figure 5 shows the Coulombic efficiency of the prepared negative electrode current collector and copper foam under the test conditions of 1 mA / cm 2 and 4 mAh / cm 2 The test conditions. Figure 6 and Figure 7 respectively show the voltage curves of copper foam and the negative electrode current collector prepared in this example at different cycle numbers under the test conditions of 1 mA / cm 2 and 4 mAh / cm 2 It can be seen that after the areal capacity is increased to 4 mAh / cm 2 the cycle stability of both Cu foam and Ni@Cu foam decreases significantly, but the Ni@Cu foam prepared in this example has a higher Coulombic efficiency than Cu foam and still has more excellent cycle stability.

[0055] Therefore, the negative electrode current collector prepared in this example has the advantages of high Coulombic efficiency and long cycle life.

[0056] Example 2

[0057] Step 1: First, prepare copper foam with a thickness of 300 μm, cut it into appropriate sizes, put it into a 1 M H2SO4 solution for acid treatment for 10 min to remove the surface oxide layer, then wash it with deionized water, then wash and wipe it with acetone multiple times, then put it into absolute ethanol for ultrasonic cleaning treatment for 15 min, finally wash it with deionized water multiple times, wipe off the excess water stains with lint-free paper, and then put it into a vacuum drying oven and dry it at 40 °C for 15 h.

[0058] Step 2, Prepare a nickel nitrate solution with a concentration of 0.5 M. Dissolve the nickel salt in an appropriate amount of deionized water or ethanol, and stir evenly until completely dissolved. Add a small amount (a few drops with a dropper) of 0.1 wt% sodium dodecyl sulfate to improve the uniformity and stability of the solution.

[0059] Step 3, Immerse the pretreated copper foam into the prepared nickel salt solution, ensuring that the copper foam is completely submerged. Soak it at room temperature for 15 h to allow the nickel salt to fully penetrate into the pores of the copper foam. After soaking, take out the copper foam and rinse it with deionized water to remove the excess nickel salt on the surface.

[0060] Step 4, Air-dry the impregnated copper foam at room temperature or dry it with a hot air blower. Then place it in a drying oven and dry it at 60 °C for 3 h to ensure complete drying. Next, put the treated copper foam in a porcelain boat and perform heat treatment in a tubular furnace under an argon atmosphere (containing 5% H2). During the heat treatment process, the nickel salt decomposes, and nickel ions diffuse into the copper foam matrix to form a nickel-doped layer. The heat treatment temperature is 600 °C, keep it at a constant temperature for 4 h, and the heating rate is 5 °C / min. After the heat treatment is completed, take out the copper foam from the tubular furnace and let it cool naturally to room temperature, then wipe its surface with anhydrous ethanol. First, pass argon at an appropriate flow rate at room temperature for 30 min before the heat treatment.

[0061] Example 3

[0062] Step 1, First, prepare copper foam with a thickness of 300 μm, cut it into appropriate sizes, put it into a 0.5 M HNO3 solution for acid treatment for 5 min to remove the surface oxide layer, then wash it with deionized water, then clean and wipe it with acetone multiple times, then put it into anhydrous ethanol for ultrasonic cleaning treatment for 15 min, finally wash it with deionized water multiple times, wipe the excess water stains with dust-free paper, and then put it into a vacuum drying oven and dry it at 40 °C for 15 h.

[0063] Step 2, Prepare a nickel nitrate solution with a concentration of 0.1 M. Dissolve the nickel salt in an appropriate amount of deionized water or ethanol, and stir evenly until completely dissolved; add a small amount (a few drops with a dropper) of 0.05 wt% sodium dodecyl sulfate to improve the uniformity and stability of the solution.

[0064] Step 3, Immerse the pretreated copper foam into the prepared nickel salt solution, ensuring that the copper foam is completely submerged. Soak it at room temperature for 20 h to allow the nickel salt to fully penetrate into the pores of the copper foam. After soaking, take out the copper foam and rinse it with deionized water to remove the excess nickel salt on the surface.

[0065] Step 4: Air-dry the impregnated copper foam at room temperature or dry it with hot air; then place it in a drying oven and dry it at 80 °C for 2 h to ensure complete drying; then put the treated copper foam in a porcelain boat and place it in a tubular furnace under an argon atmosphere (containing 5% H2) for heat treatment. During the heat treatment, the nickel salt decomposes, and nickel ions diffuse into the copper foam matrix to form a nickel-doped layer; the heat treatment temperature is 700 °C, keep the temperature constant for 2 h, and the heating rate is 6 °C / min. After the heat treatment is completed, take out the copper foam from the tubular furnace and let it cool naturally to room temperature, and wipe its surface with absolute ethanol; before the heat treatment, pass argon at an appropriate flow rate at room temperature for 30 min.

[0066] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a negative electrode current collector, characterized in that, It includes the following steps: S1, Prepare a nickel salt solution; S2, Immerse the copper foam in the nickel salt solution, and after the immersion is completed, take out the copper foam and perform cleaning and drying treatments in sequence; S3, Place the dried copper foam in an argon atmosphere containing hydrogen for heat treatment, so that nickel ions diffuse into the matrix of the copper foam to form a nickel-doped layer.

2. The preparation method of the negative electrode current collector according to claim 1, characterized in that, The nickel salt solution includes at least one of nickel nitrate, nickel chloride, nickel sulfate, and nickel acetate.

3. The preparation method of the negative electrode current collector according to claim 1, characterized in that, The nickel salt solution is a nickel nitrate solution; The concentration of the nickel nitrate solution is 0.1 - 1M.

4. The method for preparing a negative electrode current collector according to claim 1, characterized in that, The nickel salt solution also contains a surfactant; The surfactant includes at least one of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.

5. The preparation method of the negative electrode current collector according to claim 4, wherein The surfactant is sodium dodecyl sulfate, and the addition amount is 0.05wt% - 0.5wt%.

6. The method for preparing the negative electrode current collector according to claim 1, wherein, In the step S2, the copper foam is immersed in the nickel salt solution for 10 - 20h.

7. The method for preparing the negative electrode current collector according to claim 1, wherein, In the step S3, in the argon atmosphere containing hydrogen, the content of hydrogen is 5%.

8. The method for preparing the negative electrode current collector according to claim 1, wherein, In the step S3, the heat treatment temperature is 500 - 700°C, keep the temperature constant for 2 - 6h, and the heating rate is 4 - 6°C / min.

9. The negative electrode current collector prepared by the preparation method of the negative electrode current collector according to any one of claims 1 - 8.

10. A lithium metal battery without a negative electrode, characterized in that, It includes a positive electrode, an electrolyte, a separator, and the negative electrode current collector prepared by the preparation method of the negative electrode current collector according to any one of claims 1 - 8.

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