High performance battery current collector, method of making and use in metal batteries

Abstract

The application belongs to the technical field of batteries, and particularly relates to a high-performance battery current collector, a preparation method thereof and application of the high-performance battery current collector in metal batteries. A supported catalyst is prepared by mixing a carbon material carrier and a metal precursor, then the supported catalyst is mixed with a binder to prepare a slurry, and the slurry is coated on a current collector to prepare the high-performance battery current collector after drying. The current collector is modified, a high-performance SEI layer is constructed in situ and controllably, the SEI layer formed after modification has a thin size, is rich in inorganic substances and has a high Young's modulus, can promote ion transmission, resist dendrite growth and improve long-cycle stability.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to a high-performance battery current collector, its preparation method, and its application in metal batteries. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Metal anodes are considered one of the most promising high-energy anode systems due to their high theoretical capacity. Metal-free designs can further improve energy density, but dendrite growth and volume expansion during cycling severely limit their practical application. Existing technologies demonstrate that constructing a high-performance SEI layer is an effective solution to these problems.

[0004] An ideal SEI layer should be electronically insulating, thereby delaying further reactions between the electrode and the electrolyte; it should also have the ability to conduct ions rapidly, with solvated ions transferring to the surface of the SEI layer under an applied electric field, and the SEI layer desolvating the ions and transferring the exposed ions to the negative electrode; in addition, the SEI layer should have good mechanical properties to resist large volume changes during metal deposition / stripping.

[0005] The inventors discovered that existing technologies that rely on controlling the type and concentration of solute solvents, screening electrolyte additives, and constructing artificial SEI layers can lead to problems such as increased electrolyte viscosity, increased costs, and more complex processes, hindering practical applications. Currently, while researchers have explored methods to improve SEI layer performance using current collector coating slurries, this typically involves adding inorganic salts to the positive electrode carbon coating or the negative electrode active material. This results in excessively high decomposition potentials and incomplete decomposition of the inorganic salts, ultimately affecting the overall energy density of the battery. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a high-performance battery current collector, its preparation method, and its application in metal batteries. This invention achieves in-situ controllable construction of a high-performance SEI layer rich in inorganic materials by introducing catalytic sites, thereby promoting ion transport, resisting dendrite growth, and enhancing long-cycle stability.

[0007] Specifically, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a high-performance battery current collector, the high-performance battery current collector comprising a current collector substrate and a slurry coating disposed on the surface of the current collector substrate, the slurry coating comprising a carbon-supported metal catalyst and a binder; the carbon-supported metal catalyst comprising a carbon material support and a metal precursor; the binder being used to firmly attach the supported catalyst to the substrate.

[0009] Preferably, the carbon material carrier includes, but is not limited to, carbon black, nitrogen / sulfur / phosphorus heteroatom-doped carbon, graphene, carbon nanotubes, Mxenes, metal-organic frameworks and their derivatives; the heteroatoms in the heteroatom-doped carbon are selected from at least one of nitrogen, sulfur and phosphorus, and are preferably nitrogen-doped carbon.

[0010] Preferably, the metal precursor is selected from one or more of metal chlorides, metal nitrates, and acetylacetone metal compounds; the metal is selected from at least one of iron, cobalt, nickel, ruthenium, rhodium, palladium, silver, iridium, platinum, and gold, preferably ruthenium.

[0011] Preferably, the adhesive is selected from one or more of sodium carboxymethyl cellulose, styrene-butadiene rubber, polyacrylonitrile, polyvinyl alcohol, polytetrafluoroethylene, polyvinylidene fluoride, and polyimide; preferably, the adhesive is selected from sodium carboxymethyl cellulose.

[0012] A second aspect of the present invention provides a method for preparing a high-performance battery current collector, comprising the following steps:

[0013] S1. A carbon-supported metal catalyst is prepared by mixing a carbon material support and a metal precursor and dispersing them in an organic solvent.

[0014] S2. The carbon-supported metal catalyst is mixed with a binder to prepare a slurry;

[0015] S3. The slurry is coated onto the current collector substrate and dried to obtain a high-performance battery current collector.

[0016] Preferably, in step S1, the mass ratio of the carbon material carrier to the metal precursor is 10:1-50:1.

[0017] More preferably, the mass ratio of the carbon material carrier to the metal precursor is 15:1.

[0018] Preferably, in step S1, the mixture after the carbon material carrier and the metal precursor are mixed and dispersed is subjected to ultrasonication, centrifugal washing, drying and heat treatment in sequence.

[0019] The ultrasonic time for the mixture is 10–30 min;

[0020] The centrifugal washing operation is as follows: wash 2 to 3 times at a rate of 4300 to 5500 r / s and 2 to 4 min / time;

[0021] The drying process is selected from one or more of the following: natural drying, infrared lamp irradiation drying, room temperature vacuum drying, freeze drying, and high temperature drying in a forced-air drying oven.

[0022] The drying temperature is 60–90°C, and the drying time is 8–24 hours.

[0023] The heat treatment is carried out under an inert atmosphere; preferably, the inert atmosphere is one of nitrogen or argon.

[0024] The heat treatment temperature is 200–600℃; the heat treatment time is 1–5 hours.

[0025] More preferably, in step S1, the mixture after the carbon material carrier and the metal precursor are mixed and dispersed is subjected to ultrasonication, centrifugal washing, drying and heat treatment in sequence.

[0026] The ultrasonic time for the mixture is 20 minutes;

[0027] The centrifugal washing operation is as follows: wash 3 times at a rate of 5000 r / s and 3 min / time;

[0028] The drying temperature is 80℃, and the drying time is 12 hours;

[0029] The heat treatment temperature is 300℃; the heat treatment time is 2 hours.

[0030] Preferably, in step S1, the organic solvent is selected from one or more of methanol, ethanol, ethylene glycol, and isopropanol; more preferably, the solvent is selected from ethanol.

[0031] Preferably, in step S2, the slurry is prepared by mixing a carbon-supported metal catalyst and a binder in a mass ratio of 1:1 to 10:1.

[0032] More preferably, the slurry is prepared by mixing a carbon-supported metal catalyst and a binder at a mass ratio of 9:1.

[0033] Preferably, in step S3, the current collector substrate is selected from one or more of stainless steel foil, aluminum foil, copper foil, and carbon paper.

[0034] Preferably, in step S3, the coating method is selected from one or more of gravure coating, coating, and spraying.

[0035] Preferably, in step S3, the coating thickness is 5–10 μm; more preferably, the coating thickness is 10 μm.

[0036] Preferably, in step S3, the drying temperature is 80-150°C and the drying time is 8-15 hours; more preferably, the drying temperature is 110°C and the drying time is 12 hours.

[0037] A third aspect of the present invention provides an application of the high-performance battery current collector described in the first aspect in ion battery systems, metal battery systems, electrodeless battery systems, and solid-state battery systems.

[0038] A fourth aspect of the present invention provides a negative electrode-free metal battery, the negative electrode-free metal battery comprising the high-performance battery current collector described in the first aspect; the negative electrode-free metal battery further comprises: a positive electrode sheet, a separator, an electrolyte, and a battery casing.

[0039] Preferably, the positive electrode includes a positive current collector and a positive electrode material layer located on the surface of the positive current collector.

[0040] More preferably, the positive electrode current collector is one or more of stainless steel foil, aluminum foil, copper foil, and carbon paper; the positive electrode active material included in the positive electrode material layer is selected from one or more of lithium cobalt oxide, ternary materials, lithium iron phosphate, sodium vanadium phosphate, layered oxides, and Prussian blue analogues.

[0041] Preferably, the separator is selected from one or more of the following: polypropylene separator (PP), polyethylene separator (PE), polypropylene / polyethylene double-layer composite membrane (PP / PE), polypropylene / polyethylene / polypropylene triple-layer composite membrane (PP / PE / PP), polyimide electrospun separator (PI), cellulose nonwoven separator, polyethylene terephthalate nonwoven separator (PET), and separator with ceramic coating; the separator serves as a separator between the positive electrode and the modified current collector.

[0042] Preferably, the electrolyte is selected from one or more of gel electrolytes, solid electrolytes, and electrolyte solutions; the electrolyte solution includes a salt and a non-aqueous solvent; the salt is composed of alkali metal cations and anions, and the cations include, but are not limited to, Li. + Na + K + Anions include, but are not limited to, PF6. - BF4 - AsF6 - ClO4 - B(C6H5)4 - CH3SO3 - CF3SO3 - N(SO2CF3)2 - C(SO2CF3)3 - SiF6- BOB - The non-aqueous solvent is selected from one or more of carbonate compounds, carboxylic acid ester compounds, ether compounds, and other organic solvents.

[0043] The beneficial effects of one or more of the above technical solutions are as follows:

[0044] (1) By modifying the current collector, the present invention realizes the in-situ controllable construction of a high-performance SEI layer, avoiding the use of high-concentration electrolyte and additives, simplifying the experimental process and reducing costs.

[0045] (2) By introducing a catalyst, this invention promotes the decomposition of inorganic salts in the electrolyte components, rapidly forming a robust and dense inorganic layer that hinders further decomposition of the electrolyte. The modified SEI layer has a thin size, is rich in inorganic substances, and has a high Young's modulus, which can promote ion transport, resist dendrite growth, and improve long-cycle stability.

[0046] (3) The alkali metal battery containing high-performance battery current collector prepared by the present invention can achieve highly reversible deposition stripping; the negative electrode-free alkali metal battery containing high-performance battery current collector prepared by the present invention can achieve high energy density.

[0047] (4) In the process of preparing high-performance battery current collectors in this invention, the materials and reagents used from the synthesis of catalytic active materials to the assembly of negative electrode-free batteries are all materials that have been widely commercialized, are widely available, inexpensive and have stable performance, which can ensure continuous and stable mass production. Attached Figure Description

[0048] Figure 1 The images show the XRD patterns of the carbon-supported ruthenium catalyst in Example 1 and the carbon support in Comparative Example 3.

[0049] Figure 2 The images show HRTEM images of the carbon-supported ruthenium catalyst in Example 1 and the carbon support in Comparative Example 3, where a is the carbon support and b is the carbon-supported ruthenium catalyst.

[0050] Figure 3 NaF was used to form the SEI layer of ToF-SIMS in Example 2 and Comparative Example 1. - and C2H3O - 3D composition diagram, where a is copper foil and b is copper foil coated with carbon-supported ruthenium catalyst;

[0051] Figure 4 AFM images of the SEI layers formed in Example 2, Comparative Example 1, and Comparative Example 5, where a is copper foil, b is copper foil coated with carbon support, and c is copper foil coated with carbon-supported ruthenium catalyst.

[0052] Figure 5The image shows the morphology of a half-cell assembled with a composite current collector without a negative electrode, as provided in Example 2, Comparative Example 1, and Comparative Example 5, during the deposition of a sodium metal negative electrode. In the image, a is a copper foil, b is a copper foil coated with a carbon support, and c is a copper foil coated with a carbon-supported ruthenium catalyst.

[0053] Figure 6 The half-cell assembled with a negative electrode-free sodium metal battery composite current collector, as provided in Example 2, Comparative Example 1, and Comparative Example 5, operates at 2 mA cm⁻¹. -2 Current density and 2mAh cm -2 Reversibility test of electroplating and stripping under sodium deposition conditions;

[0054] Figure 7 This is a comparison graph showing the cycle performance of sodium metal batteries without negative electrodes in Example 4 and Comparative Example 3.

[0055] Figure 8 The half-cells assembled with negative electrode-less lithium metal battery composite current collectors for Example 3 and Comparative Example 2 were tested at 1 mA / cm². -2 Current density and 1mAh cm -2 Reversibility testing of electroplating and stripping under lithium deposition conditions. Detailed Implementation

[0056] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0057] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0058] Example 1: This example provides a method for preparing a high-performance battery current collector, including the following steps:

[0059] (1) Dissolve 10g glucose and 1g urea in deionized water, heat to 80°C, stir and evaporate to dryness, and sinter at 900°C under argon atmosphere to obtain carbon (nitrogen-doped carbon) material carrier.

[0060] (2) 150 mg of carbon (nitrogen-doped carbon) material support and 10 mg of ruthenium trichloride were dispersed in a solvent, sonicated and stirred continuously for 10 h, centrifuged and washed, dried at 80 °C, and heated to 300 °C under argon atmosphere for 2 h to obtain carbon-supported ruthenium catalyst.

[0061] (3) The carbon-supported ruthenium catalyst and sodium carboxymethyl cellulose (CMC) binder were mixed at a mass ratio of 9:1 to prepare a slurry;

[0062] (4) The slurry was coated onto the copper foil current collector and dried at 110°C for 12 hours to obtain the carbon-supported ruthenium catalyst modified current collector.

[0063] Example 2: This example provides a half-cell assembled using the high-performance battery current collector prepared in Example 1.

[0064] A coin cell was assembled using the carbon-supported ruthenium catalyst modified current collector prepared in Example 1 as the working electrode and sodium metal as the counter electrode.

[0065] Example 3: This example provides a half-cell assembled using the high-performance battery current collector prepared in Example 1.

[0066] A coin cell was assembled using the carbon-supported ruthenium catalyst modified current collector prepared in Example 1 as the working electrode and lithium metal as the counter electrode.

[0067] Example 4: This example provides a negative electrode-free sodium metal battery containing the high-performance battery current collector prepared in Example 1.

[0068] A slurry was prepared by dissolving sodium vanadium phosphate (positive electrode active material), PVDF (binder), and Super P (conductive agent) in N-methylpyrrolidone solvent at a mass ratio of 8:1:1 and stirring until homogeneous. This slurry was then coated onto aluminum foil and vacuum-dried at 110°C for 12 hours to form a positive electrode sheet. The sheet was assembled in a glove box, with the carbon-supported ruthenium catalyst-modified current collector prepared in Example 1 placed on the negative electrode side, resulting in a sodium metal battery without a negative electrode.

[0069] Comparative Example 1: Unlike Example 2, a coin cell half-cell was assembled by directly using a copper foil current collector as the working electrode and sodium metal as the counter electrode.

[0070] Comparative Example 2: The difference from Example 3 is that a coin cell half-cell is assembled by directly using a copper foil current collector as the working electrode and lithium metal as the counter electrode.

[0071] Comparative Example 3: Unlike Example 4, in this example, sodium vanadium phosphate (positive electrode active material), PVDF (binder), and Super P (conductive agent) were dissolved in N-methylpyrrolidone solvent at a mass ratio of 8:1:1 and stirred until homogeneous to prepare a slurry. This slurry was then coated onto aluminum foil and vacuum-dried at 110°C for 12 hours to form a positive electrode sheet. The sheet was assembled in a glove box, with a copper foil current collector placed on the negative electrode side, resulting in a sodium metal battery without a negative electrode.

[0072] Comparative Example 4: Unlike Example 1, this comparative example did not involve loading metal compounds onto the carbon material. The specific preparation method included the following steps:

[0073] (1) Dissolve 10g glucose and 1g urea in deionized water, heat to 80°C, stir and evaporate to dryness, and sinter at 900°C under argon atmosphere to obtain carbon (nitrogen-doped carbon) material carrier.

[0074] (2) The carbon carrier and sodium carboxymethyl cellulose (CMC) binder were mixed at a mass ratio of 9:1 to prepare a slurry;

[0075] (3) The slurry is coated onto the current collector and dried to obtain a carbon-modified current collector.

[0076] Comparative Example 5: This comparative example provides a half-cell assembled with a modified current collector prepared in Comparative Example 4.

[0077] A coin cell was assembled using the carbon-modified current collector prepared in Comparative Example 4 as the working electrode and sodium metal as the counter electrode.

[0078] Material characterization

[0079] In this embodiment, X-ray diffraction (XRD) was performed on the carbon-supported ruthenium catalyst obtained in step (2) of Example 1 and the carbon material support obtained in step (1) of Comparative Example 4. Figure 1 ) and high-resolution transmission electron microscopy (HRTEM, Figure 2 ) representation.

[0080] The results are as follows Figure 1 and Figure 2 As shown, the XRD pattern exhibits typical amorphous carbon peak characteristics, and the HRTEM image shows that the carbon material is ultrathin. This indicates that Comparative Example 4 synthesized an ultrathin amorphous nitrogen-doped carbon material (NC). In Example 1, this amorphous carbon material was used as a support to load ruthenium metal to obtain a catalyst material (Ru-NC). The HRTEM image shows that the ruthenium particles are small in size and relatively uniformly distributed, and no Ru-related peaks appeared in the XRD pattern.

[0081] Figure 3 The figures show the ToF-SIMS 3D composition diagrams of the SEI layers formed in the half-cells of Example 2 and Comparative Example 1. As shown in Figure a, the SEI layer formed on the surface of the pure copper current collector has a low NaF content. As can be seen from Figure b, in Example 2, due to the introduction of Ru catalytic sites, the SEI layer formed on the surface of the Ru-NC modified copper current collector contains more inorganic NaF, which will help promote the transport of sodium ions in the SEI layer and achieve faster kinetics.

[0082] Figure 4The AFM test results show that in Comparative Example 1, the SEI layer formed on the surface of the unmodified current collector is thick and has poor mechanical properties; in Comparative Example 5, the mechanical properties of the SEI layer generated after NC modification are improved to a certain extent; in Example 2, an ultra-thin SEI layer with excellent mechanical properties is formed on the surface of the current collector after Ru-NC modification.

[0083] Figure 5 The deposition morphologies of sodium metal in Examples 2, 1, and 5 are shown. In Comparative Example 1, the sodium metal deposition morphology on the unmodified current collector surface is irregular, with dendrites and the lowest Young's modulus. In Comparative Example 5, the deposition morphology after NC modification is improved, but the amount is small. In Example 2, the sodium metal is uniformly deposited on the current collector surface after Ru-NC modification, and the highest Young's modulus is achieved.

[0084] Electrochemical performance testing

[0085] In application examples of metal half-cells, such as Figure 6 As shown, at 2mA cm -2 2mAh cm -2 Under high current density and large area capacity, the Ru-NC modified current collector in Example 2 can achieve 1000 stable cycles. In contrast, in Comparative Examples 1 and 5, the cycle life is only less than 200 cycles.

[0086] current collector Cycle life Comparative Example 1 Cu 89 Comparative Example 5 NC-Cu 106 Example 2 Ru-NC-Cu 1000

[0087] In application examples of sodium metal batteries without negative electrodes, such as Figure 7 As shown, Example 4 achieves an initial coulombic efficiency of 90.75% and a capacity retention of 98.1% (100 cycles), while Comparative Example 3 shows an initial coulombic efficiency of only 26.14%, with the capacity decreasing to 1.19 mAh g⁻¹ after the tenth cycle. -1 .

[0088] like Figure 8 As shown, it also exhibits excellent electrochemical performance when used in lithium metal half-cells. Comparative Example 2 failed within 50 cycles, while Example 3 could cycle stably for 600 cycles.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-performance battery current collector, characterized in that, The high-performance battery current collector includes a current collector substrate and a slurry coating disposed on the surface of the current collector substrate. The slurry coating includes a carbon-supported metal catalyst and a binder. The carbon-supported metal catalyst includes a carbon material support and a metal precursor. The binder is used to firmly attach the carbon-supported metal catalyst to the substrate. The carbon material carrier includes carbon black, heteroatom-doped carbon, graphene, carbon nanotubes, Mxenes or metal-organic frameworks and their derivatives; the heteroatoms in the heteroatom-doped carbon are selected from at least one of nitrogen, sulfur and phosphorus; the metal precursor is selected from one or more of metal chlorides, metal nitrates, and acetylacetone metal compounds; the metal is selected from at least one of iron, cobalt, nickel, ruthenium, rhodium, palladium, silver, iridium, platinum and gold.

2. The high-performance battery current collector as described in claim 1, characterized in that, The heteroatom in the heteroatom-doped carbon is nitrogen.

3. The high-performance battery current collector as described in claim 1, characterized in that, The metal is ruthenium.

4. The high-performance battery current collector as described in claim 1, characterized in that, The adhesive is selected from one or more of sodium carboxymethyl cellulose, styrene-butadiene rubber, polyacrylonitrile, polyvinyl alcohol, polytetrafluoroethylene, polyvinylidene fluoride, and polyimide.

5. The high-performance battery current collector as described in claim 4, characterized in that, The binder is sodium carboxymethyl cellulose.

6. A method for preparing a high-performance battery current collector as described in claim 1, characterized in that, Includes the following steps: S1. A carbon-supported metal catalyst is prepared by mixing a carbon material support and a metal precursor and dispersing them in an organic solvent. S2. The carbon-supported metal catalyst is mixed with a binder to prepare a slurry; S3. The slurry is coated onto the current collector substrate and dried to obtain a high-performance battery current collector.

7. The preparation method according to claim 6, characterized in that, In step S1, the mass ratio of the carbon material carrier to the metal precursor is 10:1-50:

1.

8. The preparation method according to claim 7, characterized in that, The mass ratio of the carbon material carrier to the metal precursor is 15:

1.

9. The preparation method according to claim 6, characterized in that, In step S1, the mixture of the carbon material carrier and the metal precursor is subjected to ultrasonication, centrifugal washing, drying and heat treatment in sequence.

10. The preparation method according to claim 9, characterized in that, The ultrasonic time for the mixture is 10-30 min.

11. The preparation method according to claim 9, characterized in that, The centrifugal washing operation is as follows: wash 2 to 3 times at a rate of 4300~5500 r / s and 2~4 min / time.

12. The preparation method according to claim 9, characterized in that, The drying process is selected from one or more of the following: natural drying, infrared lamp irradiation drying, room temperature vacuum drying, freeze drying, and high-temperature drying in a forced-air drying oven.

13. The preparation method according to claim 9, characterized in that, The drying temperature is 60~90℃, and the drying time is 8~24 h.

14. The preparation method according to claim 9, characterized in that, The heat treatment is performed under an inert atmosphere.

15. The preparation method according to claim 14, characterized in that, The inert atmosphere is either nitrogen or argon.

16. The preparation method according to claim 9, characterized in that, The heat treatment temperature is 200~600℃; the heat treatment time is 1~5 h.

17. The preparation method according to claim 6, characterized in that, The organic solvent is selected from one or more of methanol, ethanol, ethylene glycol, and isopropanol.

18. The preparation method according to claim 17, characterized in that, The solvent is ethanol.

19. The preparation method according to claim 6, characterized in that, In step S2, the slurry is prepared by mixing a carbon-supported metal catalyst and a binder in a mass ratio of 1:1 to 10:

1.

20. The preparation method according to claim 19, characterized in that, The slurry is prepared by mixing a carbon-supported metal catalyst and a binder at a mass ratio of 9:

1.

21. The preparation method according to claim 6, characterized in that, In step S3, the coating method is selected from one or more of gravure coating, coating, and spraying.

22. The preparation method according to claim 6, characterized in that, The coating thickness is 5~10 μm.

23. The preparation method according to claim 22, characterized in that, The coating thickness is 10 μm.

24. The preparation method according to claim 6, characterized in that, The drying temperature is 80~150 ℃, and the drying time is 8~15 h.

25. The preparation method according to claim 24, characterized in that, The drying temperature is 110 ℃ and the drying time is 12 h.

26. The application of the high-performance battery current collector according to any one of claims 1 to 5 in ion battery systems, metal battery systems, negative electrode-free battery systems and solid-state battery systems.

27. A negative electrode-free metal battery, characterized in that, The negative electrode-free metal battery includes the high-performance battery current collector as described in any one of claims 1 to 5; the negative electrode-free metal battery further includes: a positive electrode sheet, a separator, an electrolyte, and a battery casing; The positive electrode includes a positive current collector and a positive electrode material layer located on the surface of the positive current collector.

28. The negative electrode-free metal battery as described in claim 27, characterized in that, The positive current collector is one or more of stainless steel foil, aluminum foil, copper foil, and carbon paper.

29. The negative electrode-free metal battery as described in claim 27, characterized in that, The positive electrode material layer includes one or more of the following: lithium cobalt oxide, ternary materials, lithium iron phosphate, sodium vanadium phosphate, layered oxides, and Prussian blue analogues.

30. The negative electrode-free metal battery according to any one of claims 27 to 29, characterized in that, The diaphragm is selected from one or more of the following: polypropylene diaphragm (PP), polyethylene diaphragm (PE), polypropylene / polyethylene double-layer composite film (PP / PE), polypropylene / polyethylene / polypropylene triple-layer composite film (PP / PE / PP), polyimide electrospun diaphragm (PI), cellulose nonwoven fabric diaphragm, polyethylene terephthalate nonwoven fabric diaphragm (PET), and diaphragm with ceramic coating. The diaphragm serves as a separator between the positive electrode and the modified current collector; The electrolyte is selected from one or more of gel electrolytes, solid electrolytes, and electrolyte solutions; the electrolyte solution includes a salt and a non-aqueous solvent; the salt is composed of alkali metal cations and anions; the non-aqueous solvent is selected from one or more of carbonate compounds, carboxylic acid ester compounds, and ether compounds.

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