Artificial interface layer / current collector collaborative strategy-based dendrite-free metal anode for rechargeable battery, preparation method and battery

Abstract

The invention provides a dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector collaborative strategy, and relates to the field of batteries. The metal anode comprises an artificial interface layer, an active material layer and a current collector layer which are sequentially arranged, and the preparation method comprises the following steps: constructing the artificial interface layer on the surface of one side of the active material layer, and connecting the other side of the active material layer with a current collector to obtain the metal anode. The metal anode can intervene in the deposition / stripping process of metal ions, changes the deposition / stripping mode of the metal ions, realizes spatial separation of deposition and deposition / stripping sites of the metal ions on the back of the anode, and effectively improves the interface problem of the metal anode.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular, to a dendrite-free metal anode for rechargeable batteries, a preparation method thereof, and a battery based on a collaborative strategy of an artificial interface layer / current collector. Background Art

[0002] Both large-scale grid energy storage and portable mobile devices require energy storage devices with high energy density and high safety and stability. Metal-ion batteries are one of the excellent choices. Using a pure metal anode is beneficial to further improve the energy density of metal-ion batteries. The pure metal anode has the advantages of low redox potential, good electrical conductivity, and high energy density. However, interface problems such as uncontrollable dendrite growth, corrosion, side reactions, and structural instability in metal anodes based on the deposition / stripping energy storage mechanism seriously affect the practical application of pure metal anodes, and these interface problems accelerate the decay of battery performance. Therefore, solving the interface problems existing in metal anodes is crucial for the efficient, safe, and stable utilization of metal-ion batteries.

[0003] In fact, for these interface problems, their root cause lies in the in-situ deposition / stripping of metal ions, which causes periodic volume changes in the metal anode, resulting in instability at the electrode / electrolyte interface. Specifically, during the ion deposition process, metal ions are deposited at the interface where they were originally stripped (as shown), and due to stripping, corrosion, and the structure of the material itself, this interface is uneven, thus causing uneven distribution of the interface electric field and uneven deposition, which damages the electrode / electrolyte interface (SEI), making the anode metal directly contact the electrolyte and triggering serious interface problems. Figure 1 As shown, due to stripping, corrosion, and the structure of the material itself, this interface is uneven, thus causing uneven distribution of the interface electric field and uneven deposition, which damages the electrode / electrolyte interface (SEI), making the anode metal directly contact the electrolyte and triggering serious interface problems.

[0004] Currently, many studies are dedicated to strategies such as artificial interface layers, electrode structure design, electrolyte optimization, and solid electrolytes to solve these interface problems. However, most of these improvement strategies are based on the surface phenomena of interface problems and ignore the root cause of interface problems: the "in-situ" deposition / stripping of metal ions, that is, the deposition and stripping of metal ions occur at the same interface. For example, most artificial interface layer designs inhibit the interface problems existing in metal anodes by preventing direct contact between the metal anode and the electrolyte, regulating the transport rate of metal ions, and the solvation structure of metal ions. However, the in-situ deposition / stripping of metal ions will cause durability problems in the artificial interface layer, and cracking and peeling will occur during long-term cycling. Therefore, it is necessary to seek a metal anode that can change the metal ion deposition / stripping mode to solve the interface problems caused by the in-situ deposition / stripping of metal ions, so as to achieve a metal anode with high safety, high stability, and high capacity. Summary of the Invention

[0005] The object of the present invention is to provide a dendrite-free metal anode for rechargeable batteries based on the artificial interface layer / current collector collaborative strategy, so as to solve the interface problems existing in the existing metal anodes, such as uncontrollable dendrite growth, corrosion, side reactions, and unstable structure. This metal anode can intervene in the deposition / stripping process of metal ions, change the deposition / stripping mode of metal ions, realize the deposition of metal ions on the back of the anode and the spatial separation of deposition / stripping sites, and effectively improve the interface problems existing in the metal anode.

[0006] Another object of the present invention is to provide a preparation method of a dendrite-free metal anode for rechargeable batteries based on the artificial interface layer / current collector collaborative strategy. The preparation method has simple process, easy-to-obtain materials, and easy-to-realize production conditions, and has obvious advantages in reducing production costs and large-scale industrial production applications.

[0007] The third object of the present invention is to provide a battery with high safety and stability.

[0008] The present invention solves its technical problems by adopting the following technical solutions.

[0009] On the one hand, an embodiment of the present invention provides a dendrite-free metal anode for rechargeable batteries based on the artificial interface layer / current collector collaborative strategy, which includes an artificial interface layer, an active material layer, and a current collector layer arranged in sequence. Among them, the artificial interface layer does not react with the electrolyte and is also insoluble in the electrolyte. The ionic conductivity of the artificial interface layer is lower than 10 -3 S cm -1 , and the electronic conductivity is lower than 10 5 S m -1 ;

[0010] In some embodiments of the present invention, the artificial interface layer is a coating, plating, or film formed by inorganic substances or / and organic substances on the surface layer of the active material. Among them, the film can be a dense continuous film or a non-dense continuous film.

[0011] In some embodiments of the present invention, the inorganic substance is one or more of oxides, fluorides, insoluble salts, sulfides, selenides, and nitrides.

[0012] In some embodiments of the present invention, the organic substance is one or more of polyvinylidene fluoride, polyacrylic acid, polyvinyl alcohol, polyaniline, polytetrafluoroethylene, sodium carboxymethyl cellulose, styrene-butadiene rubber, polyacrylonitrile, polyacrylamide, polyethylene, sodium alginate, and chitosan.

[0013] In some embodiments of the present invention, the oxide is a metal oxide or a non-metal oxide. The metal oxide is one of aluminum oxide, iron oxide, iron tetroxide, magnesium oxide, copper oxide, zinc oxide, titanium oxide, and manganese oxide. The non-metal oxide is silicon oxide. The fluoride is one of calcium fluoride, barium fluoride, lithium fluoride, and zinc fluoride. The sparingly soluble salt is one of calcium carbonate, barium sulfate, and barium carbonate. The sulfide is cadmium sulfide or zinc sulfide. The selenide is zinc selenide or tungsten selenide. The nitride is titanium nitride or tantalum nitride.

[0014] In some embodiments of the present invention, the thickness of the artificial interface layer is 1 nm - 100 μm.

[0015] In some embodiments of the present invention, the active material layer is an active metal or an active metal alloy, and is a whole piece of active metal sheet or an active metal coating. The active metal is one of lithium, sodium, potassium, zinc, and magnesium, and the purity is not less than 99.99%. The active metal alloy is one of magnesium-lithium alloy, zinc-lithium alloy, and zinc-magnesium alloy.

[0016] In some embodiments of the present invention, the current collector layer is a conductor with a three-dimensional porous structure. The three-dimensional porous structure conductor is one of foam metal, metal mesh, and organic or inorganic conductive three-dimensional porous frameworks.

[0017] In some embodiments of the present invention, the redox potential of the current collector layer is higher than the redox potential of the active material layer. The electronic conductivity of the current collector layer is 10 5 -10 7 S m -1 。

[0018] On the other hand, embodiments of the present invention provide a method for preparing a dendrite-free metal anode for a rechargeable battery based on the artificial interface layer / current collector synergistic strategy, including the following steps: constructing an artificial interface layer on one side surface of the active material layer, and then connecting the other side of the active material layer to the current collector to obtain the metal anode.

[0019] In some embodiments of the present invention, the artificial interface layer is constructed by a coating method, a sputtering film-forming method, a vacuum evaporation method, an electron beam evaporation method, or an attachment method.

[0020] In some embodiments of the present invention, the coating method includes the following steps: mixing the raw materials of the artificial interface layer, a binder, and a solvent to form a slurry, and then coating the slurry on the surface of the active material layer and drying to form the artificial interface layer.

[0021] The mass ratio of the raw materials of the artificial interface layer to the binder is 9:1 or 8:2.

[0022] The thickness of the active material layer is 20 μm ≤ d ≤ 50 μm;

[0023] The drying temperature is 60°C - 80°C;

[0024] In a third aspect, an embodiment of the present invention provides a battery, and the anode of the battery is the above-mentioned metal anode. The battery is one of a lithium-ion battery, a sodium-ion battery, a potassium-ion battery, a magnesium-ion battery, or an aqueous zinc-ion battery.

[0025] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0026] For the metal anode provided by the present invention, an artificial interface layer and a current collector layer are respectively arranged on both sides of the active material layer. The artificial interface layer can directly isolate the electrode from direct contact with the electrolyte, preventing the occurrence of corrosion reactions. The artificial interface layer can intervene in the deposition / stripping process of metal ions, change the deposition / stripping mode of metal ions, realize the deposition of metal ions on the back of the anode and the spatial separation of deposition / stripping sites, and effectively improve the interface problems existing in the metal anode.

[0027] The artificial interface layer and the current collector layer act synergistically. Driven by the electric field distribution, the affinity for active ions, and the difference in redox potential, metal ions can be deposited on the current collector. Since the current collector is on the back of the active material layer, therefore, it effectively avoids the short circuit of the battery caused by uncontrollable dendrite growth and realizes the high safety of the metal anode.

[0028] The artificial interface layer and the current collector layer act synergistically, realizing the spatial separation of metal ion deposition / stripping sites while enabling the directional deposition of metal ions. Specifically, during the charge and discharge process, metal ions are stripped from the back of the active material layer, while the deposition of metal ions occurs on the current collector, effectively preventing the periodic volume change of the electrode caused by the in-situ deposition / stripping of metal ions, stabilizing the SEI film of the electrode, avoiding serious interface problems caused by direct contact between the active material layer and the electrolyte, and realizing the high stability of the metal anode.

[0029] The preparation method of the present invention has simple technology, easy-to-obtain materials, and easy-to-realize production conditions, and has obvious advantages in reducing production costs and large-scale industrial production applications. Compared with the traditional artificial interface layer design and current collector design, the metal anode provided by the present invention has more excellent electrochemical performance, more obvious improvement effect, simpler process, does not require secondary processing of the material itself, and can save time and cost in the production process. Description of the Drawings

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0031] Figure 1 Schematic diagram of ion stripping and deposition of metal anodes in the prior art;

[0032] Figure 2 Schematic diagram of ion stripping and deposition of the metal anode of the present invention;

[0033] Figure 3 Schematic diagram of the zinc anode structure in Example 1;

[0034] Figure 4 Comparison chart of the cycling performance of the battery in Example 1 and the battery in Comparative Example 1;

[0035] Figure 5 Morphologies of each part of the disassembled anode of the battery after 1000 cycles in Example 1 and Comparative Example 1;

[0036] Figure 6 Comparison chart of the cycling performance of the battery in Example 6 and the battery in Comparative Example 2;

[0037] Figure 7 Morphologies of each part of the disassembled anode of the battery after 500 cycles in Example 6 and Comparative Example 2. Detailed implementation manners

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For the reagents or instruments whose manufacturers are not specified, they are all conventional products that can be obtained through commercial purchase.

[0039] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to specific embodiments.

[0040] Example 1

[0041] Construction of the artificial interface layer: A commercial lithium fluoride material and polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 9:1 in an N-methylpyrrolidone solution, homogenized, and the slurry is coated on a commercial zinc foil with a thickness of 80 μm and dried in an oven at 60 °C. A zinc metal electrode with a lithium fluoride artificial interface layer is obtained by cutting.

[0042] Take commercial nickel foam with a thickness of 1 mm, cut it to the same size as the zinc metal electrode, and the current collector layer is obtained.

[0043] Place the cut zinc metal electrode with an artificial interface layer on the nickel foam current collector layer, and the high-safety and high-stability zinc metal anode is obtained.

[0044] The positive electrode is MnO 2 Material: Manganese dioxide, conductive agent carbon black, and binder polytetrafluoroethylene (PTFE) are made into a colloid with a mass ratio of 7:2:1 using ethanol as a solvent. Then, through roll pressing, it is made into a thin sheet with a certain thickness and attached to the graphite paper as the positive electrode sheet. The separator is an aqueous glass fiber separator (AGM), and the electrolyte is 3 mol L -1 ZnSO 4 (+0.2 mol L - 1 MnSO 4 ) aqueous solution, and it is assembled with the metal zinc anode with a lithium fluoride artificial interface layer and a nickel foam current collector layer into a button battery to test the electrochemical performance and observe the interface condition after cycling.

[0045] Example 2

[0046] The only difference from Example 1 is that the artificial interface layer is made into a slurry by calcium carbonate and PVDF with a mass ratio of 9:1 using N-methylpyrrolidone as a solvent, coated on a 80-μm commercial zinc foil, and dried at 60 °C. The remaining raw materials and preparation methods are the same as those in Example 1.

[0047] Example 3

[0048] The only difference from Example 1 is that commercial titanium mesh with a thickness of 50 μm is taken, cut to the same size as the zinc metal electrode, and used as the current collector layer. The remaining raw materials and preparation methods are the same as those in Example 1.

[0049] Example 4

[0050] The only difference from Example 1 is that commercial nickel mesh with a thickness of 50 μm is taken, cut to the same size as the zinc metal electrode, and used as the current collector layer. The remaining raw materials and preparation methods are the same as those in Example 1.

[0051] Example 5

[0052] The only difference from Example 1 is that the lithium fluoride artificial interface layer is obtained by DC magnetron sputtering technology. The commercial lithium fluoride target and commercial zinc foil are placed in the magnetron sputtering vacuum sample chamber, and the vacuum is pumped to 3×10 -3A bar is introduced with high-purity argon (99.99%). Sputtering is carried out at a power of 60 W for 2 h, and the artificial lithium fluoride interface layer is about 10 μm. Then, the zinc foil with the artificial lithium fluoride interface layer is taken out and made into a zinc metal pole piece. The remaining raw materials and preparation methods are the same as those in Example 1.

[0053] Example 6

[0054] In a glove box filled with argon, take a polyimide tape, attach it to the surface of a commercial lithium metal sheet, and cut it to make its size the same as that of the lithium metal sheet, thus obtaining a lithium metal pole piece with a polyimide artificial interface layer. Take a commercial nickel foam with a thickness of 1 mm and cut it to the same size as the lithium metal pole piece, thus obtaining a current collector layer.

[0055] In a glove box filled with argon, place the cut lithium metal sheet with a polyimide artificial interface layer on the nickel foam current collector layer, thus obtaining the high-safety and high-stability lithium metal anode.

[0056] The positive electrode is LiCoO 2 Material: Lithium cobaltate, conductive agent carbon black, and binder PVDF are made into a slurry in a mass ratio of 7:2:1 with N-methylpyrrolidone as the solvent. The slurry is coated on an 8-μm commercial aluminum foil, dried in an oven at 60 °C, and roll-pressed to obtain a positive electrode pole piece. The separator is a glass fiber separator (GFD), and the electrolyte is a commercial LiPF 6 Electrolyte (its composition is: 1 mol L - 1 LiPF 6 dissolved in a mixed solution of ethylene carbonate / diethyl carbonate with a volume ratio of 7:3), and assembled with the lithium metal anode with a polyimide artificial interface layer and a nickel foam current collector layer into a button battery to test the electrochemical performance and observe the interface condition after cycling.

[0057] Example 7

[0058] The difference from Example 6 is that the artificial interface layer is composed of PVDF. PVDF and N-methylpyrrolidone are made into a slurry in a mass ratio of 3:50. The slurry is coated on a stainless steel foil sheet, dried in an oven at 60 °C, and the PVDF film is peeled off from the stainless steel foil. In the glove box, it is attached to a commercial lithium metal sheet to obtain a lithium metal pole piece with a PVDF artificial interface layer. The remaining raw materials and preparation methods are the same as those in Example 6.

[0059] Example 8

[0060] The difference from Example 6 is that a commercial copper foam with a thickness of 1.5 mm is taken and cut to the same size as the lithium metal pole piece to obtain a copper foam current collector layer. The remaining raw materials and preparation methods are the same as those in Example 6.

[0061] Comparative Example 1

[0062] Take the same commercial zinc foil as in Example 1 and cut it into zinc metal electrodes.

[0063] The positive electrode is MnO 2 material. Mix manganese dioxide, conductive agent carbon black, and binder PTFE in a mass ratio of 7:2:1, make a colloid with ethanol as the solvent, then roll it to make a thin sheet of a certain thickness, and attach it to the graphite paper as the positive electrode. The separator is an AGM separator, and the electrolyte is 3 mol L -1 ZnSO 4 (+0.2 mol L -1 MnSO 4 ) aqueous solution, and assemble it with the zinc metal negative electrode (without artificial interface layer and current collector) into a button battery to test the electrochemical performance and observe the interface condition after cycling.

[0064] Comparative Example 2

[0065] Take the same commercial lithium sheet as in Example 6 and cut it into lithium metal electrodes.

[0066] The positive electrode is LiCoO 2 material. Make a slurry of lithium cobaltate, conductive agent carbon black, and binder PVDF in a mass ratio of 7:2:1 with N-methylpyrrolidone as the solvent, coat the slurry on an 8-μm commercial aluminum foil, dry it in an oven at 60 °C, and roll it to the same thickness to obtain the positive electrode. The separator is a GFD separator, and the electrolyte is a commercial LiPF 6 electrolyte (its composition is: 1 mol L - 1 LiPF 6 dissolved in a mixed solution of ethylene carbonate / diethyl carbonate with a volume ratio of 7:3). Assemble it with the lithium metal negative electrode (without artificial interface layer and current collector) into a button battery to test the electrochemical performance and observe the interface condition after cycling.

[0067] Test the cycling ability of the aqueous zinc-ion batteries assembled in Examples 1, 2, 3, 4, 5 and Comparative Example 1 at 2 A g -1 during charge and discharge at room temperature, record the performance of each example after 1000 cycles, and make a record, as shown in Table 1. And disassemble the batteries after cycling to observe the morphological and structural changes of each part of the anode.

[0068] Table 1

[0069]

[0070]

[0071] Figure 3 It is a schematic diagram of the zinc anode structure in Example 1.

[0072] Figure 4 It is a comparison chart of the cycling performance of the full cell assembled with the zinc anode having a lithium fluoride artificial interface layer and a nickel foam current collector layer in this Example 1 and the full cell in Comparative Example 1.

[0073] Figure 5 It is the morphology of each part of the disassembled anode of the battery after 1000 cycles in Example 1 and Comparative Example 1.

[0074] The assembled lithium-ion batteries in Examples 6, 7, 8 and Comparative Example 2 were tested for charge-discharge cycling performance at a current density of 0.2 A g -1 The performance of each example after 500 cycles was recorded and tabulated as shown in Table 2. The batteries after cycling were disassembled to observe the morphological and structural changes of each part of the anode.

[0075] Table 2

[0076]

[0077]

[0078] Figure 6 It is a comparison chart of the cycling performance of the full cell assembled with the lithium anode having a polyimide artificial interface layer and a nickel foam current collector layer in this Example 6 and the full cell in Comparative Example 2.

[0079] Figure 7 It is a morphological diagram of the composition of each part of the disassembled anode of the full cell assembled with the lithium anode having a polyimide artificial interface layer and a nickel foam current collector layer in this Example 6 and the full cell in Comparative Example 2 after cycling.

[0080] From Table 1 and Figure 3 、 4As can be seen from Table 5, in the aqueous zinc-ion battery, the capacity retention rates of all the examples after 1000 cycles are significantly better than that of Comparative Example 1. Moreover, by comparing the morphologies of the zinc anodes in Example 1 and Comparative Example 1 (without artificial interface layer and current collector) after cycling, it is found that after cycling, there are no obvious dendrites on the surface of the separator and the artificial interface layer in Example 1, and obvious zinc deposition occurs on the nickel foam current collector. However, obvious zinc deposition exists on the zinc foil surface in Comparative Example 1, and obvious zinc dendrites exist on the separator due to the uneven zinc deposition. In Example 1, zinc ions are deposited on the current collector, and the spatial separation of the zinc ion deposition / stripping sites is also achieved, thus avoiding battery short circuit caused by uncontrollable dendrite growth, effectively stabilizing the SEI film at the anode interface, improving the interface problems existing in the zinc metal anode, and thus realizing a high-performance zinc metal anode.

[0081] As can be seen from Table 2 and Figure 6 、 Figure 7 it can be seen that in the lithium-ion battery, the capacity retention rate and Coulombic efficiency of all the examples after 500 cycles are better than those of Comparative Example 2. Moreover, by comparing the morphologies of the lithium anodes in Example 6 and Comparative Example 2 (without artificial interface layer and current collector) after cycling, it is found that after cycling, the phenomenon of back deposition and spatial separation of the deposition / stripping sites of lithium in Example 6 is obvious.

[0082] In summary, the present invention provides a dendrite-free metal anode for rechargeable batteries and a preparation method thereof based on the artificial interface layer / current collector synergistic strategy. Among them, the artificial interface layer plays a dual role on the electrode surface: it can effectively hinder the disordered transport of metal ions and, through its guiding effect, guide metal ions to avoid direct deposition on the anode surface. At the same time, the current collector layer plays a key guiding role in the metal deposition process and serves as the substrate for deposition. The synergistic effect of the two enables the deposition and stripping activities of metal ions to occur in the back region of the electrode, and realizes the spatial decoupling of the deposition and stripping sites - the deposition process is mainly concentrated on the current collector layer, while the stripping process mainly occurs in the active layer. By changing the traditional metal ion deposition / stripping mode and effectively decoupling the deposition and stripping sites in space, the interface problems of the metal anode (as shown in Figure 2 ) can be effectively solved, the safety and stability of the metal ion battery can be improved, and the efficient and stable application of the metal anode can be realized.

[0083] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the present invention claimed, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

Claims

1. A dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector synergistic strategy, characterized in that: It includes an artificial interface layer, an active material layer and a current collector layer which are arranged in sequence.

2. The dendrite-free metal anode for rechargeable batteries based on the artificial interface layer / current collector synergistic strategy according to claim 1, characterized in that: The artificial interface layer is a coating, plating or film formed by inorganic and / or organic substances on the surface of the active material layer; the inorganic substance is one or more of oxides, fluorides, sparingly soluble salts, sulfides, selenides and nitrides; the organic substance is one or more of polyvinylidene fluoride, polyacrylic acid, polyvinyl alcohol, polyaniline, polytetrafluoroethylene, sodium carboxymethyl cellulose, styrene-butadiene rubber, polyacrylonitrile, polyacrylamide, polyethylene, sodium alginate and chitosan.

3. The dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector synergistic strategy according to claim 1, characterized in that: The thickness of the artificial interface layer is 1nm-100μm; the artificial interface layer does not react with the electrolyte, nor dissolve in the electrolyte, and the ionic conductivity of the artificial interface layer is less than 10 -3 S cm -1 , the electronic conductivity is less than 10 5 Sm -1 .

4. The dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector synergistic strategy according to claim 1, characterized in that: The active material layer is an active metal or an active metal alloy, the active metal is one of lithium, sodium, potassium, zinc and magnesium; the active metal alloy is one of magnesium-lithium alloy, zinc-lithium alloy and zinc-magnesium alloy.

5. The dendrite-free metal anode for rechargeable battery based on artificial interface layer / current collector synergistic strategy according to claim 1, characterized in that: The current collector layer is a conductor with a three-dimensional porous structure; the three-dimensional porous structure conductor is one of foam metal, metal mesh, and organic or inorganic conductive three-dimensional porous framework.

6. The dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector synergistic strategy according to claim 1, characterized in that: The redox potential of the current collector layer is higher than the redox potential of the active material layer.

7. A method for preparing a dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector synergistic strategy as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: An artificial interface layer is constructed on one surface of the active material layer, and the other side of the active material layer is connected to a current collector to obtain the metal anode.

8. The method for preparing a dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector synergistic strategy according to claim 7, characterized in that: The artificial interface layer is constructed by coating, sputtering, vacuum evaporation, electron beam evaporation or attachment.

9. The method for preparing a dendrite-free metal anode for a rechargeable battery based on an artificial interface layer / current collector synergistic strategy according to claim 8, characterized in that: The coating method The method comprises the following steps: mixing raw materials, a binder and a solvent of the artificial interface layer to prepare slurry, coating the slurry on the surface of the active material layer, and drying to form the artificial interface layer.

10. A battery, characterized in that: The anode of the battery is the metal anode according to any one of claims 1 to 9.

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