Lithium metal battery and method for manufacturing a lithium metal battery negative electrode including

Abstract

Provided are a lithium metal battery and a method for manufacturing a negative electrode included in the lithium metal battery, the lithium metal battery including a positive electrode, a negative electrode, and an electrolyte disposed between the positive electrode and the negative electrode, in which the negative electrode includes a negative electrode current collector, a negative electrode active material layer disposed on the negative electrode current collector, and a porous layer including a porous structure, the porous layer includes a first region exposed on the negative electrode active material layer and a second region inserted into the negative electrode active material layer, and the negative electrode active material layer includes the second region into which the porous layer is inserted and a third region into which the porous layer is not inserted.

Description

Technical Field

[0001] This disclosure relates to lithium metal batteries and methods for manufacturing a lithium metal battery negative electrode included in a lithium metal battery. Background Technology

[0002] Carbonaceous anode active materials such as graphite are widely used in currently commercially available lithium metal batteries. Lithium metal batteries exhibit high stability because carbonaceous anode active materials do not show volume changes during charge and discharge. Graphite, however, has a low theoretical capacity of approximately 372 mAh / g.

[0003] Lithium metal can be used as the negative electrode active material. Lithium metal has a very high theoretical capacity of approximately 3860 mAh / g. However, due to the formation and growth of dendrites on the surface of lithium metal caused by side reactions with the electrolyte during charge and discharge, lithium metal can potentially cause short circuits between the positive and negative electrodes. Therefore, the lifespan characteristics of lithium metal batteries, including lithium metal, deteriorate.

[0004] There is a need to develop methods to improve the lifespan characteristics of lithium metal batteries, including lithium metal. Summary of the Invention

[0005] Technical issues A lithium metal battery with a novel negative electrode for lithium metal batteries is provided.

[0006] A method for manufacturing a negative electrode for a lithium metal battery, which is included in a lithium metal battery, is also provided.

[0007] Technical solution According to this disclosure, A lithium metal battery includes: a positive electrode; a negative electrode; and an electrolyte disposed between the positive and negative electrodes. The negative electrode includes: a negative electrode current collector; The negative electrode active material layer is disposed on the negative electrode current collector; and Porous layers, including porous structures, The porous layer includes a first region exposed on the negative electrode active material layer and a second region inserted into the negative electrode active material layer, and The negative electrode active material layer includes a second region in which a porous layer is inserted and a third region in which a porous layer is not inserted.

[0008] According to another aspect of this disclosure, A method for manufacturing a negative electrode for lithium metal batteries includes the following steps: A negative electrode structure is prepared, comprising a negative electrode current collector, a negative electrode active material layer disposed on the negative electrode current collector, and a porous layer disposed on the negative electrode active material layer; and At least a portion of the porous layer is inserted into the negative electrode active material layer by rolling the negative electrode structure via a roller press.

[0009] Beneficial effects According to an embodiment, a lithium metal battery with improved cycle characteristics can be provided by using a negative electrode that includes a porous layer. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view of a lithium metal battery according to an example embodiment.

[0011] Figure 2 This is a cross-sectional view of the negative electrode according to an example embodiment.

[0012] Figure 3 This is a cross-sectional view of the negative electrode according to another example embodiment.

[0013] Figure 4 This is a schematic diagram of a lithium metal battery according to an example embodiment.

[0014] Figure 5 This is a schematic diagram of a lithium metal battery according to an example embodiment.

[0015] Figure 6 This is a schematic diagram of a lithium metal battery according to an example embodiment. Detailed Implementation

[0016] During the charge-discharge process of a lithium metal battery, in which lithium metal is used as the negative electrode active material, a lithium-containing metal layer precipitates and dissolves between the negative electrode current collector and the electrolyte layer. With repeated charge-discharge cycles, the negative electrode active material layer accumulates impurities remaining in the electrode, electrolyte decomposition products, and so on. Therefore, the negative electrode active material layer has a rough and hard surface due to the impurities it contains. Lithium dendrites form on this rough lithium-containing metal layer. These lithium dendrites may continue to grow during the charge-discharge process, leading to a short circuit between the positive and negative electrodes. Furthermore, with repeated charge-discharge cycles, the electrolyte is continuously consumed due to side reactions, potentially causing a rapid deterioration in the cycle characteristics of the lithium metal battery.

[0017] The lithium metal battery according to an embodiment includes a negative electrode comprising a porous layer and a negative electrode active material layer disposed between the porous layer and a negative electrode current collector, such that the porous layer and the negative electrode current collector are separated in the negative electrode. Therefore, the formation of lithium dendrites in the negative electrode active material layer is suppressed, and electrolyte consumption is suppressed, thereby improving the cycle characteristics of the lithium metal battery including this negative electrode.

[0018] The inventive concept described below allows for various modifications and numerous embodiments, which will be illustrated in the accompanying drawings and detailed in the written description. However, this is not intended to limit the inventive concept to a particular mode of practice, and it will be understood that all modifications, equivalents, and substitutions that do not depart from the spirit and scope of the inventive concept are included within its scope.

[0019] The terminology used herein is for describing particular embodiments only and is not intended to limit the inventive concept. Unless the context clearly distinguishes them, expressions used in the singular include those used in the plural. In this specification, it will be understood that terms such as “comprising” or “having” are intended to indicate the presence of features, quantities, operations, elements, portions, components, materials, or combinations thereof disclosed in the specification, and are not intended to exclude the possibility that one or more other features, quantities, operations, elements, portions, components, materials, or combinations thereof may be present or added. As used herein, “ / ” may be interpreted as “and” or “or” as appropriate.

[0020] In the accompanying drawings, the thickness of individual layers and regions may be enlarged or reduced for clarity. Throughout the specification, the same reference numerals denote the same elements. It will be understood throughout the specification that when an element (such as a layer, film, region, or plate) is referred to as being "on" another element, it may be directly on said other element, or there may be an intervening element between them. Although the terms first, second, etc., may be used herein to describe various components, these components should not be limited by these terms. These terms are used only to distinguish one component from another. In this specification and the accompanying drawings, components having substantially the same functional construction are indicated by the same reference numerals, and redundant descriptions are omitted.

[0021] As used herein, the “size” of a particle can be, for example, “particle diameter”. The “particle diameter” represents the average diameter of spherical particles or the average length of the major axis of non-spherical particles. The particle diameter can be measured using a particle size analyzer (PSA). The “particle diameter” can be, for example, the average particle diameter. The average particle diameter can be, for example, the median particle diameter (D50). The median particle diameter (D50) can be the particle diameter corresponding to 50% of the cumulative volume calculated from, for example, the smallest particle in a particle size distribution measured by laser diffraction.

[0022] In this disclosure, the term "metal" includes metals and metalloids (such as silicon and germanium) that are in an elemental or ionic state.

[0023] In this disclosure, the term "alloy" refers to a combination of two or more metals.

[0024] In public, the term "positive electrode active material" refers to a material used in positive electrodes that allows for lithiation and delithiation.

[0025] In public, the term "negative electrode active material" refers to a material used for a negative electrode that allows for lithiation and delithiation.

[0026] In the public discourse, the terms "lithiation" and "performing lithiation" refer to the process of adding lithium to a positive or negative electrode active material.

[0027] In public discourse, the terms “delithiation” and “performing delithiation” refer to the process of removing lithium from positive or negative electrode active materials.

[0028] In this disclosure, the terms “charging” and “performing a charge” refer to the process by which a battery supplies electrochemical energy.

[0029] In the public domain, the terms “discharge” and “performing a discharge” refer to the process of removing electrochemical energy from a battery.

[0030] In this disclosure, the terms "positive electrode" and "positive electrode" refer to the electrode in which electrochemical reduction and lithiation occur during discharge.

[0031] In the publication, the terms "negative electrode" and "negative electrode" refer to the electrode in which electrochemical oxidation and delithiation occur during discharge.

[0032] Figure 1 This is a cross-sectional view of a lithium metal battery according to an example embodiment. Figure 2 This is a cross-sectional view of the negative electrode according to an example embodiment. Figure 3 This is a cross-sectional view of the negative electrode according to another example embodiment.

[0033] In the following description, a lithium metal battery including a negative electrode for a lithium metal battery and a method for manufacturing a negative electrode for a lithium metal battery will be described in more detail with reference to the accompanying drawings.

[0034] The lithium metal battery according to an embodiment includes: a positive electrode 10; a negative electrode 20; and an electrolyte layer 30 disposed between the positive electrode 10 and the negative electrode 20. The negative electrode 20 includes: a negative electrode current collector 210; a negative electrode active material layer 220 disposed on the negative electrode current collector 210; and a porous layer 230, comprising a porous structure. The porous layer 230 includes a first region A1 exposed on the negative electrode active material layer and a second region A2 inserted into the negative electrode active material layer. The negative electrode active material layer 220 includes the second region A2 into which the porous layer 230 is inserted and a third region A3 into which the porous layer 230 is not inserted. For example, because the negative electrode 20 included in the lithium metal battery 1 includes the third region A3 into which the porous layer 230 is not inserted, the porous layer 230 can be separated from the negative electrode current collector 210 in the negative electrode active material layer 220. In this way, cracks or damage that may occur in the negative electrode 20 during the process of inserting the porous layer 230 into the negative electrode active material layer 220 can be prevented. Therefore, the cycle characteristics of the lithium metal battery 1 including the negative electrode 20 can be improved.

[0035] Furthermore, the first region A1 of the porous layer 230 exposed on the negative electrode active material layer (which serves as the lithium host during charging of the lithium metal battery 1) can effectively prevent the formation of lithium dendrites on the negative electrode active material layer 220. Additionally, the second region A2, where the porous layer 230 and the negative electrode active material layer 220 are stacked, serves as a lithium source and can improve the cycle characteristics of the lithium metal battery 1 including the second region A2.

[0036] [negative electrode] Reference Figure 2 and Figure 3 According to the embodiment, the negative electrode 20 may include: a negative electrode current collector 210; a negative electrode active material layer 220 disposed on the negative electrode current collector; and a porous layer 230, including a porous structure, wherein the porous layer 230 may include a first region A1 exposed on the negative electrode active material layer and a second region A2 inserted into the negative electrode active material layer, and the negative electrode active material layer 220 may include the second region A2 into which the porous layer 230 is inserted and a third region A3 into which the porous layer 230 is not inserted.

[0037] According to an embodiment, the thickness of the first region A1 can satisfy 100% to 130% of the following expression 1.

[0038] Expression 1 Positive electrode current density (mAh / cm) 2 )×4.89µm / (mAh / cm 2 )×(1 / porosity of the first region) For example, Expression 1 represents the minimum height (μm) required to fill the first region A1 of the porous layer 230 with lithium ions migrating from the positive electrode 10 to the negative electrode 20. For example, the value is 4.89 μm / (mAh / cm). 2 ) refers to each 1mAh / cm 2 The positive current density is filled with the height of lithium. For example, when the thickness of the first region A1 satisfies 100% to 130% of the value of Expression 1, lithium ions migrating from the positive electrode 10 to the negative electrode 20 are deposited in the first region A1 of the porous layer 230, thereby effectively preventing the formation of lithium dendrites during the charging process.

[0039] According to an embodiment, when the lithium metal battery 1 is charged, a lithium plating layer 240 is formed on the negative electrode active material layer 220, and the thickness of the lithium plating layer 240 can be 130% or less of the thickness of the first region A1. For example, the thickness of the lithium plating layer 240 can be 100% to 130% of the thickness of the first region A1. For example, the thickness of the lithium plating layer 240 can be the same as the thickness of the first region A1.

[0040] For example, at least a portion of the lithium plating 240 may be located within the porous layer 230. In this case, because at least a portion of the lithium plating 240 is formed within the porous layer 230, uneven growth of the lithium plating 240 can be prevented, and the formation of lithium dendrites can be effectively prevented.

[0041] According to an embodiment, the porosity of the porous structure included in the first region A1 of the porous layer 230 can be from 1% to 99%. For example, the porosity of the porous structure included in the first region A1 of the porous layer 230 can be from 1% to 99%, 50% to 99%, or 50% to 90%.

[0042] According to an embodiment, the porosity of the porous structure included in the second region A2 of the porous layer 230 can be less than the porosity of the porous structure included in the first region A1. For example, the porosity of the porous structure included in the porous layer 230 can decrease in the direction from the first region A1 to the second region A2. For example, before charging, the porosity of the porous structure included in the second region A2 can be 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, 5% or less, 1% or less, or 0%.

[0043] According to an embodiment, the size of the pores included in the first region of the porous layer 230 can be from 1 nm to 10 μm. For example, the size of the pores included in the first region of the porous layer 230 can be from 1 nm to 5 μm, 1 nm to 3 μm, 10 nm to 10 μm, 0.1 μm to 10 μm, 0.2 μm to 10 μm, 0.5 μm to 10 μm, 1 μm to 10 μm, or 1 μm to 3 μm.

[0044] According to an embodiment, the thickness of the first region A1 in the porous layer 230 can be from 1 μm to 100 μm, and the thickness of the second region A2 in the porous layer 230 can be from 1 μm to 50 μm. For example, the thickness of the first region A1 in the porous layer 230 can be from 1 μm to 100 μm, 5 μm to 100 μm, 10 μm to 100 μm, 15 μm to 100 μm, 20 μm to 100 μm, 25 μm to 100 μm, 1 μm to 90 μm, 1 μm to 80 μm, 1 μm to 70 μm, or 25 μm to 70 μm. For example, the thickness of the second region A2 in the porous layer 230 can be 1 μm to 50 μm, 5 μm to 50 μm, 10 μm to 50 μm, 1 μm to 40 μm, 1 μm to 30 μm, 1 μm to 25 μm, or 10 μm to 25 μm.

[0045] According to an embodiment, the thickness of the second region A2 can be 70% or less of the thickness of the negative electrode active material layer 220. According to an embodiment, the thickness of the second region A2 can be 50% or less, 10% to 50%, or 20% to 50% of the thickness of the negative electrode active material layer 220. For example, when the thickness of the second region A2 meets 70% or less of the thickness of the negative electrode active material layer 220, damage to the negative electrode 20 that may occur during the process of inserting the porous layer 230 into the negative electrode active material layer 220 can be effectively prevented. Therefore, the lifespan characteristics of the lithium metal battery 1 including the negative electrode 20 can be improved.

[0046] According to the embodiment, the hardness of the porous layer 230 can be greater than the hardness of the negative electrode active material layer 220. For example, hardness refers to the rigidity of a material, and hardness can be measured using a Brinell hardness tester or the like. For example, because the hardness of the porous layer 230 is greater than the hardness of the negative electrode active material layer 220, the porous layer 230 can be inserted into the negative electrode active material layer 220 more easily, and cracks that may occur in the negative electrode 20 during the insertion process can be prevented more effectively.

[0047] According to an embodiment, the porous layer 230 comprises a metal or a carbonaceous material. The metal may include copper (Cu), nickel (Ni), stainless steel (SUS), iron (Fe), or cobalt (Co). For example, the metal may include copper (Cu), nickel (Ni), stainless steel (SUS), or iron (Fe). For example, the carbonaceous material may include carbon steel.

[0048] According to an embodiment, the porous structure included in the porous layer 230 may include a foam structure or a mesh structure. For example, the porous structure may include a foam structure. For example, when the porous structure includes a foam structure, lithium ions can move more easily through the three-dimensional path within the foam structure, thereby reducing internal resistance. Therefore, the charging / discharging efficiency of the lithium metal battery 1 can be improved.

[0049] According to an embodiment, the porous structure included in the porous layer 230 can be acid-treated. For example, the porous structure can be acid-treated with hydrochloric acid, nitric acid, or sulfuric acid. For example, when the porous structure is acid-treated, oxides present on the surface of the porous structure can be removed, thereby increasing the proportion of metal atoms on the surface of the porous structure. Therefore, lithium ions can be easily oxidized and reduced in the porous structure, which further improves the cycle characteristics and charge / discharge characteristics of the lithium metal battery 1 including the porous structure.

[0050] According to an embodiment, when analyzed by X-ray photoelectron spectroscopy (XPS), the acid-treated porous structure can have an oxide peak to metal peak ratio of 50:1 to 1:1. For example, when analyzed by XPS, the acid-treated porous structure can have an oxide peak to metal peak ratio of 40:1 to 1:1, 30:1 to 1:1, 20:1 to 1:1, 50:1 to 2:1, 50:1 to 3:1, 30:1 to 2:1, or 20:1 to 3:1.

[0051] According to embodiments, the porous structure may further include a coating layer formed on its surface. For example, the coating layer may include a lithiophilic material. For example, the coating layer may include gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), or zinc (Zn). For example, the coating layer formed on the surface of the porous structure can enhance reactivity with lithium ions, thereby further improving the charge / discharge efficiency of the lithium metal battery 1.

[0052] [Negative electrode: Negative electrode active material layer] According to an embodiment, the negative electrode active material layer 220 may include, for example, lithium foil, lithium powder, lithium plating, carbonaceous materials, or any combination thereof. The negative electrode active material layer including lithium foil may be, for example, a lithium metal layer. The negative electrode active material layer including lithium powder may be formed by applying a slurry including lithium powder, a binder, etc., onto the negative electrode current collector. The binder may be a fluorinated binder such as polyvinylidene fluoride (PVDF). The negative electrode active material layer may not include carbonaceous negative electrode active material. Therefore, the negative electrode active material layer may be formed from metallic negative electrode active material.

[0053] The thickness of the negative electrode active material layer 220 can be, for example, 0.1 μm to 100 μm, 0.1 μm to 80 μm, 1 μm to 80 μm, or 10 μm to 80 μm, but is not limited thereto, and can be adjusted according to the shape, capacity, etc. of the lithium metal battery. If the negative electrode active material layer 220 is too thick, the structural stability of the lithium metal battery may deteriorate and side reactions may increase. If the negative electrode active material layer 220 is too thin, the energy density of the lithium metal battery may decrease. The thickness of the lithium foil can be, for example, 1 μm to 50 μm, 1 μm to 30 μm, 10 μm to 30 μm, or 10 μm to 80 μm. If the lithium foil has a thickness within the above range, the lifespan characteristics of the lithium metal battery can be further improved. The particle size of the lithium powder can be, for example, 0.1 μm to 3 μm or 0.1 μm to 2 μm. If the lithium powder has a thickness within the above range, the lifespan characteristics of the lithium metal battery can be further improved.

[0054] For example, the negative electrode active material layer 220 may include a second region A2 in which the porous layer 230 is inserted and a third region A3 in which the porous layer 230 is not inserted. For example, because the negative electrode active material layer 220 includes the third region A3, the negative electrode current collector 210 can be separated from the porous layer 230. Therefore, because the active material included in the third region A3 is used during the charge and discharge process, damage to the negative electrode 20 that may occur during the process of inserting the porous layer 230 into the negative electrode active material layer 220 can be effectively prevented, and the life characteristics of the lithium metal battery can be improved.

[0055] According to an embodiment, the thickness of the second region A2 in the negative electrode active material layer 220 can be 70% or less of the total thickness of the negative electrode active material layer.

[0056] According to an embodiment, the thickness of the third region A3 in the negative electrode active material layer 220 can be 30% or more of the total thickness of the negative electrode active material layer. According to an embodiment, the thickness of the third region A3 in the negative electrode active material layer 220 can be from 0.3 μm to 50 μm.

[0057] [Negative electrode: Negative electrode current collector] The material constituting the negative electrode current collector 210 can be any material that does not react with lithium, that is, any conductive material that does not form an alloy or compound with lithium. The metal substrate constituting the negative electrode current collector 210 can be formed of, for example, a metal or alloy. The metal substrate can be formed of, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or alloys thereof. For example, the negative electrode current collector 210 can be in the form of sheets, foils, films, plates, porous structures, mesoporous structures, structures with through holes, polygonal rings, meshes, foams, and nonwoven structures, but is not limited thereto, and can be in any form commonly available in the art.

[0058] For example, the negative electrode current collector 210 can have a reduced thickness compared to the negative electrode current collector included in a conventional negative electrode. Therefore, the negative electrode according to this disclosure is distinguished from conventional negative electrodes that include a thick current collector by including a thin film current collector. Because the negative electrode according to the embodiment includes a thin film current collector with a reduced thickness, the thickness of the negative electrode active material layer is relatively increased in the negative electrode including the thin film current collector. Therefore, the energy density of the lithium metal battery including such a negative electrode is increased. The thickness of the negative electrode current collector 210, including the metal substrate and the intermediate layer, can be, for example, less than 15 μm, 14.5 μm or less, or 14 μm or less. The thickness of the negative electrode current collector 210 can be, for example, greater than or equal to 0.1 μm and less than 15 μm, 1 μm to 14.5 μm, 2 μm to 14 μm, 3 μm to 14 μm, 5 μm to 14 μm, or 10 μm to 14 μm.

[0059] The material constituting the negative electrode current collector 210 can be any material that does not react with lithium, that is, any conductive material that does not form an alloy or compound with lithium. The negative electrode current collector 210 can be formed, for example, a metal or alloy. The negative electrode current collector 210 can be formed, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or alloys thereof.

[0060] For example, the negative electrode current collector 210 may be in the form of a sheet, foil, film, plate, porous structure, mesoporous structure, structure with through holes, polygonal ring, mesh, foam and nonwoven structure, but is not limited thereto, and may be any form commonly available in the art.

[0061] The negative electrode current collector 210 may include, for example, a base film and metal layers disposed on one or both sides of the base film. The negative electrode current collector 210 may include a substrate, and the substrate may have a structure including the base film and metal layers disposed on one or both sides of the base film. The aforementioned intermediate layer may be further disposed on the metal layers. The base film may include, for example, a polymer. The polymer may be, for example, a thermoplastic polymer. The polymer may include, for example, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), polyimide (PI), or any combination thereof. Because the base film includes a thermoplastic polymer, the base film melts in the event of a short circuit, thereby suppressing a rapid increase in current. The base film may be, for example, an insulator. The metal layers may include, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), or alloys thereof. The metal layers can act as an electrochemical fuse, which will trip in the event of an overcurrent, thereby preventing a short circuit. By controlling the thickness of the metal layers, the limiting current and the maximum current can be adjusted. The metal layer can be plated or deposited on the base film. If the thickness of the metal layer is reduced, the limiting current and / or maximum current of the negative electrode current collector 210 decreases, thus improving the stability of the lithium metal battery under short-circuit conditions. Lead tabs can be added to the metal layer for external connections. The lead tabs can be welded to the metal layer or metal layer / base film stack structure by ultrasonic welding, laser welding, spot welding, etc. The metal layer can be electrically connected to the lead tabs when the base film and / or metal layer melt during welding. A metal sheet can be further added between the metal layer and the lead tab for a stronger weld between them. The metal sheet can be a sheet of the same material as the metal layer. The metal sheet can be, for example, metal foil and metal mesh. The metal sheet can be, for example, Al foil, copper foil, and SUS foil. By placing the metal sheet on the metal layer and performing welding with the lead tab, the lead tab can be welded to a metal sheet / metal layer stack structure or a metal sheet / metal layer / base film stack structure. When the base film, metal layer, and / or metal sheet melt during soldering, the metal layer or metal layer / metal sheet stack structure can be electrically connected to the lead tabs. Metal sheets and / or lead tabs can be further added to a portion of the metal layer. The thickness of the base film can be, for example, 1 μm to 50 μm, 1.5 μm to 50 μm, 1.5 μm to 40 μm, or 1 μm to 30 μm. When the thickness of the base film meets the above ranges, the weight of the negative electrode assembly can be reduced more effectively. The melting point of the base film can be, for example, 100°C to 300°C, 100°C to 250°C, or 100°C to 200°C. If the base film has a melting point within the above ranges, the base film can be melted during the soldering process to easily bond to the lead tabs. To improve the adhesion between the base film and the metal layer, the base film can be surface-treated (such as corona treatment).The thickness of the metal layer can be, for example, 0.01 μm to 3 μm, 0.1 μm to 3 μm, 0.1 μm to 2 μm, or 0.1 μm to 1 μm. When the thickness of the metal layer meets the above ranges, the stability of the negative electrode component can be achieved while maintaining its conductivity. The thickness of the metal sheet can be, for example, 2 μm to 10 μm, 2 μm to 7 μm, or 4 μm to 6 μm. If the thickness of the metal sheet is within the above ranges, the metal layer can be more easily connected to the lead terminals. Because the negative electrode current collector 210 has the above structure, the weight of the electrode can be reduced, thereby increasing the energy density of the lithium metal battery.

[0062] According to an embodiment, the negative electrode 20 may further include an intermediate layer disposed between the negative electrode current collector 210 and the negative electrode active material layer 220.

[0063] According to an embodiment, the intermediate layer can be disposed directly on one or both surfaces of the negative electrode current collector 210, for example. Therefore, no other layer needs to be disposed between the negative electrode current collector 210 and the intermediate layer. By disposing the intermediate layer directly on one or both surfaces of the negative electrode current collector 210, the adhesion strength between the negative electrode current collector 210 and the negative electrode active material layer 220 can be further improved.

[0064] The thickness of the intermediate layer (not shown) can be, for example, 30% or less of the thickness of the negative electrode current collector 210. The thickness of the intermediate layer (not shown) can be, for example, 0.01% to 30%, 0.1% to 30%, 0.5% to 30%, 1% to 25%, 1% to 20%, 1% to 15%, 1% to 10%, 1% to 5%, or 1% to 3% of the thickness of the negative electrode current collector 210. The thickness of the intermediate layer (not shown) can be, for example, 10 nm to 5 μm, 50 nm to 5 μm, 200 nm to 4 μm, 500 nm to 3 μm, 500 nm to 2 μm, 500 nm to 1.5 μm, or 700 nm to 1.3 μm. Because the intermediate layer (not shown) has a thickness within the above range, the adhesion strength between the negative electrode current collector 210 and the negative electrode active material layer 220 can be further improved, and the increase in interfacial resistance can be suppressed.

[0065] For example, the intermediate layer may include an adhesive. Because the intermediate layer includes an adhesive, the bond strength between the negative electrode current collector 210 and the negative electrode active material layer 220 can be further improved. The adhesive included in the intermediate layer (not shown) may be, for example, a conductive adhesive or a non-conductive adhesive.

[0066] Conductive adhesives can be, for example, ionicly conductive adhesives and / or electronically conductive adhesives. Adhesives possessing both ionic and electronic conductivity can be classified as either ionicly conductive adhesives or electronically conductive adhesives.

[0067] Ionically conductive binders can be, for example, polystyrene sulfonate (PSS), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), polyethylene oxide (PEO), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPY), polyaniline (PANI), and polyacetylene (PA). Ionically conductive binders may include polar functional groups. Ionic conductive binders including polar functional groups can be, for example, Nafion, Aquivion, Flemion, Gore, Aciplex, Morgane ADP, sulfonated poly(ether ether ketone) (SPEEK), sulfonated poly(aryl ether ketone sulfone) (SPAEKKS), sulfonated poly(aryl ether ketone) (SPAEK), poly[bis(benzimidazolidinebenzisoquinolinone)] (SPBIBI), poly(styrene sulfonate) (PSS), or lithium 9,10-diphenylanthracene-2-sulfonate (DPASLi). + The electronically conductive binder can be, for example, polyacetylene, polythiophene, polypyrrole, poly(p-phenylene), poly(phenylenevinylene), poly(phenylene sulfide), or polyaniline. The intermediate layer can be, for example, a conductive layer comprising a conductive polymer.

[0068] The binder included in the intermediate layer can be, for example, a fluorinated binder. The fluorinated binder included in the intermediate layer can be, for example, polyvinylidene fluoride (PVDF). The intermediate layer can be disposed on the negative electrode current collector 210, for example, by a dry or wet process. The intermediate layer can be, for example, an adhesive layer including a binder.

[0069] The intermediate layer may also include, for example, a carbonaceous conductive material. Because the intermediate layer includes a carbonaceous conductive material, it can be, for example, a conductive layer. The intermediate layer can be a conductive layer that includes, for example, an adhesive and a carbonaceous conductive material.

[0070] The intermediate layer can be formed on the negative electrode current collector 210 by a dry method such as CVD or PVD. The intermediate layer can also be formed on the negative electrode current collector 210 by a wet method such as spin coating or dip coating. The intermediate layer can be formed on the negative electrode current collector 210, for example, by depositing a carbonaceous conductive material on it. Dry-coated intermediate layers are formed from carbonaceous conductive materials and may not include a binder. Alternatively, an intermediate layer can be formed on the negative electrode current collector by coating a composition comprising a carbonaceous conductive material, a binder, and a solvent onto the surface of the negative electrode current collector and allowing the coated composition to dry. The intermediate layer can have a single-layer or multi-layer structure.

[0071] [Lithium metal battery] The lithium metal battery 1 according to an embodiment may include: a positive electrode 10; the aforementioned negative electrode 20; and an electrolyte layer 30 disposed between the positive electrode and the negative electrode. By including the aforementioned negative electrode, the lithium metal battery can have increased capacity and excellent lifespan characteristics.

[0072] For example, a lithium metal battery 1 may include a liquid electrolyte, a semi-solid gel electrolyte, a solid electrolyte, or any combination thereof as an electrolyte.

[0073] Although the lithium metal battery 1 is prepared, for example, by the following exemplary method, the method is not limited thereto and can be adjusted according to the desired conditions.

[0074] (negative electrode) Prepare the above-mentioned negative electrode.

[0075] (positive electrode) First, a positive electrode active material composition is prepared by mixing a positive electrode active material, a conductive material, a binder, and a solvent. The prepared positive electrode active material composition can be directly coated onto an aluminum current collector and dried to prepare a positive electrode plate in which a positive electrode active material layer 12 is formed. In other embodiments, a positive electrode 10 including the positive electrode active material layer 12 can be prepared by casting the positive electrode active material composition onto a separate support and pressing a film layer separated from the support onto an aluminum current collector.

[0076] The positive electrode active material can be any lithium-containing metal oxide commonly used in the art, without limitation. For example, the positive electrode active material can include a composite oxide of lithium with at least one metal selected from cobalt, manganese, nickel, and any combination thereof, and examples of such composites can be compounds represented by one of the following formulas: Li a A 1-b B b D2 (where 0.90≤a≤1 and 0≤b≤0.5); Li a E 1-b B b O 2-c D c (Where, 0.90≤a≤1, 0≤b≤0.5 and 0≤c≤0.05); LiE 2-b B b O 4-c D c (Where, 0 ≤ b ≤ 0.5 and 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b B c D α (Where, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α≤2); Li a Ni 1-b-c Co bB c O 2-α F α (Where, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α<2); Li a Ni 1-b- c Co b B c O 2-α F2 (where 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α<2); Li a Ni 1-b-c Mn b B c D α (Where, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α≤2); Li a Ni 1-b-c Mn b B c O 2-α F α (Where, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α<2); Li a Ni 1-b-c Mn b B c O 2-α F2 (where 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05 and 0<α<2); Li a Ni b E c G d O2 (where 0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5 and 0.001≤d≤0.1); Li a Ni b Co c Mn d G e O2 (where 0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5 and 0.001≤e≤0.1); Li a NiG b O2 (where 0.90≤a≤1 and 0.001≤b≤0.1); Li a CoG b O2 (where 0.90≤a≤1 and 0.001≤b≤0.1); Li a MnG b O2 (where 0.90≤a≤1 and 0.001≤b≤0.1); Li a Mn2G bO4 (where 0.90 ≤ a ≤ 1 and 0.001 ≤ b ≤ 0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiIO2; LiNiVO4; Li (3-f) J2(PO4)3 (where 0 ≤ f ≤ 2); Li (3-f) Fe2(PO4)3 (where 0 ≤ f ≤ 2); and LiFePO4.

[0077] In the formulas representing the above compounds, A can be Ni, Co, Mn, or any combination thereof; B can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or any combination thereof; D can be O, F, S, P, or any combination thereof; E can be Co, Mn, or any combination thereof; F can be F, S, P, or any combination thereof; G can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or any combination thereof; Q can be Ti, Mo, Mn, or any combination thereof; I can be Cr, V, Fe, Sc, Y, or any combination thereof; and J can be V, Cr, Mn, Co, Ni, Cu, or any combination thereof. The above compounds with a coating layer on their surface can also be used, or a mixture of the above compounds and compounds with a coating layer can also be used. The coating layer added to the surface of the compound can include, for example, compounds of the coating element (such as oxides of the coating element, hydroxides of the coating element, hydroxyoxides of the coating element, carbonate oxides of the coating element, or hydroxycarbonates of the coating element). The compounds constituting the coating layer can be amorphous or crystalline. The coating elements included in the coating layer can be Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or any mixture thereof. The method of forming the coating layer can be selected from methods that do not adversely affect the physical properties of the positive electrode active material. The coating method can be, for example, spraying and dip coating. These methods will be obvious to those of ordinary skill in the art, so their detailed description will not be given.

[0078] The positive electrode active material can be, for example, Li a Ni x Co y M z O 2-b A b (where 1.0 ≤ a ≤ 1.2, 0 ≤ b ≤ 0.2, 0.8 ≤ x < 1, 0 < y ≤ 0.3, 0 < z ≤ 0.3, x + y + z = 1, M is manganese (Mn), niobium (Nb), vanadium (V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W), molybdenum (Mo), iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), boron (B), or any combination thereof, and A is F, S, Cl, Br, or any combination thereof), LiNix Co y Mn z O₂ (where 0.8 ≤ x ≤ 0.95, 0 ≤ y ≤ 0.2, 0 < z ≤ 0.2 and x + y + z = 1), LiNi x Co y Al z O₂ (where 0.8 ≤ x ≤ 0.95, 0 ≤ y ≤ 0.2, 0 < z ≤ 0.2 and x + y + z = 1), LiNi x Co y Mn z Al w O₂ (where 0.8 ≤ x ≤ 0.95, 0 ≤ y ≤ 0.2, 0 < z ≤ 0.2, 0 < w ≤ 0.2 and x + y + z + w = 1), Li a Co x M y O 2-b A b (where 1.0 ≤ a ≤ 1.2, 0 ≤ b ≤ 0.2, 0.9 ≤ x ≤ 1, 0 ≤ y ≤ 0.1, x + y = 1, M is manganese (Mn), niobium (Nb), vanadium (V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W), molybdenum (Mo), iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), boron (B) or any combination thereof, and A is F, S, Cl, Br or any combination thereof), Li a Ni x Mn y M' z O 2-b A b (where 1.0 ≤ a ≤ 1.2, 0 ≤ b ≤ 0.2, 0 < x ≤ 0.3, 0.5 ≤ y < 1, 0 < z ≤ 0.3, x + y + z = 1, M' is cobalt (Co), niobium (Nb), vanadium (V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W), molybdenum (Mo), iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), boron (B) or any combination thereof, and A is F, S, Cl, Br or any combination thereof), Li a M1 x M2 y [[ID=:47]]PO 4-b X b(where 0.90 ≤ a ≤ 1.1, 0 ≤ x ≤ 0.9, 0 ≤ y ≤ 0.5, 0.9 < x + y < 1.1, 0 ≤ b ≤ 2, M1 is chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), or any combination thereof, M2 is magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), zinc (Zn), boron (B), niobium (Nb), gallium (Ga), indium (In), molybdenum (Mo), tungsten (W), aluminum (Al), silicon (Si), chromium (Cr), vanadium (V), scandium (Sc), yttrium (Y), or any combination thereof, and X is O, F, S, P, or any combination thereof), or Li a M3 z PO4 (where 0.90 ≤ a ≤ 1.1, 0.9 ≤ z ≤ 1.1, and M3 is chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), or any combination thereof).

[0079] The conductive material can be: carbon black, graphite particles, natural graphite, artificial graphite, acetylene black, Ketjen black, carbon fiber; carbon nanotubes; metals, such as copper, nickel, aluminum, and silver each used in the form of powder, fiber, or tube; or conductive polymers, such as polyphenylene derivatives, but not limited thereto, and any material commonly used as a conductive material in the art can also be used. In other embodiments, the positive electrode may not include a separate conductive material.

[0080] The binder can be vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polytetrafluoroethylene (PTFE), their mixtures, or styrene-butadiene rubber polymers, and the solvent can be N-methylpyrrolidone (NMP), acetone, and water, but not limited thereto, and any binder and solvent commonly used in the art can also be used.

[0081] A plasticizer or pore-forming agent can be further added to the positive electrode active material composition to form pores inside the electrode plate.

[0082] The amounts of the positive electrode active material, conductive material, binder, and solvent for the positive electrode 10 can be at the same level as those commonly used in lithium metal batteries. Depending on the use and structure of the lithium metal battery, at least one of the conductive material, binder, and solvent can be omitted.

[0083] Based on the total weight of the positive electrode active material layer 12, the amount of the binder included in the positive electrode 10 can be, for example, 0.1 wt% to 10 wt% or 0.1 wt% to 5 wt%. Based on the total weight of the positive electrode active material layer 12, the amount of the positive electrode active material included in the positive electrode 10 can be, for example, 80 wt% to 99 wt%, 90 wt% to 99 wt%, or 95 wt% to 99 wt%.

[0084] According to an embodiment, when the lithium metal battery 1 includes a solid electrolyte as the electrolyte, the positive electrode active material layer 12 may also include a solid electrolyte in addition to the positive electrode active material. The solid electrolyte included in the positive electrode 10 may be the same as or different from the solid electrolyte included in the electrolyte layer 30 as described below. For a detailed description of the solid electrolyte included in the positive electrode 10, refer to the electrolyte layer 30 described below.

[0085] The solid electrolyte used in the positive electrode active material layer 12 may have a smaller average particle size (D50) than that of the solid electrolyte used in the electrolyte layer 30. For example, the average particle size (D50) of the solid electrolyte used in the positive electrode active material layer 12 may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the average particle size (D50) of the solid electrolyte used in the electrolyte layer 30. The average particle size (D50) of the solid electrolyte used in the positive electrode active material layer 12 may, for example, be 0.1 μm to 2 μm, 0.2 μm to 1.5 μm, or 0.3 μm to 1.0 μm.

[0086] For example, based on the total weight of the positive electrode active material layer 12, the amount of solid electrolyte included in the positive electrode active material layer 12 can be 1 wt% to 15 wt%, 5 wt% to 15 wt%, or 8.0 wt% to 12.0 wt%.

[0087] For example, in the case where the lithium metal battery 1 includes a solid electrolyte, the positive electrode active material layer 12 included in the lithium metal battery 1 may include a binder. The binder may be styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, or polyethylene, but is not limited thereto; any binder commonly available in the art may be used. Based on the total weight of the positive electrode active material layer 12, the amount of binder included in the positive electrode active material layer 12 may be, for example, 0.1 wt% to 5 wt%, 0.5 wt% to 3 wt%, or 1.0 wt% to 2.0 wt%.

[0088] In the case where the lithium metal battery 1 includes a solid electrolyte, the positive electrode active material layer 12 included in the lithium metal battery 1 may include a conductive material. The conductive material may be, for example, a carbonaceous conductive material or a metallic conductive material. The conductive material may be, for example, graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanotubes, or metal powder, but is not limited thereto, and any conductive material commonly available in the art may also be used. Based on the total weight of the positive electrode active material layer 12, the amount of conductive material included in the positive electrode active material layer 12 may be, for example, 0.1 wt% to 10 wt%, 0.5 wt% to 5 wt%, or 1.0 wt% to 4.0 wt%. In addition to the above-described positive electrode active material, solid electrolyte, binder, and conductive material, the positive electrode active material layer 12 may also include, for example, fillers, coatings, dispersants, and ion-conducting additives.

[0089] The positive electrode current collector 11 can be in the form of a plate or foil, for example, made of aluminum (Al), indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), germanium (Ge), lithium (Li), or alloys thereof. The positive electrode current collector can be omitted. The positive electrode current collector 11 may also include a carbon layer disposed on one or both sides of the metal substrate. By additionally providing a carbon layer on the metal substrate, corrosion of the metal substrate caused by the solid electrolyte included in the positive electrode layer can be prevented, and the interfacial resistance between the positive electrode active material layer 12 and the positive electrode current collector 11 can be reduced. The thickness of the carbon layer can be, for example, 1 μm to 5 μm, 1 μm to 4 μm, or 1 μm to 3 μm. If the carbon layer thickness is too small, it may be difficult to completely prevent contact between the metal substrate and the solid electrolyte. If the carbon layer thickness is too large, the energy density of the all-solid-state lithium metal battery may decrease. The carbon layer may include amorphous carbon, crystalline carbon, etc. The thickness of the positive electrode current collector 11, including the metal substrate (optionally, and the carbon layer), can be, for example, 10 μm to 50 μm, 10 μm to 40 μm, or 10 μm to 30 μm, but is not limited thereto, and can vary depending on the desired characteristics of the all-solid-state lithium metal battery.

[0090] According to an embodiment, the positive electrode 10 may include a positive electrode current collector 11 and a positive electrode active material layer 12 disposed on the positive electrode current collector 11, and may also include inactive components disposed on the side surfaces of the positive electrode active material layer 12. The area of ​​the positive electrode active material layer 12 may be smaller than the area of ​​the electrolyte layer 30 in contact with the positive electrode active material layer 12. Because the inactive components are arranged around the side surfaces of the positive electrode active material layer 12, the area error between the positive electrode active material layer 12 and the electrolyte layer 30 can be corrected. The inactive components are components that do not include electrochemically active materials (e.g., electrode active materials). The electrode active material may be a material that allows lithium insertion / extraction. In addition to the electrode active material, the inactive components may be formed of materials commonly used in the art. The inactive components may be in contact with the electrolyte layer 30 while surrounding the side surfaces of the positive electrode active material layer 12. Because the inactive component is in contact with the electrolyte layer 30 and surrounds the side surface of the positive electrode active material layer 12, cracks in the electrolyte layer 30 caused by pressure differences during the pressure application process can be effectively suppressed in the portion of the electrolyte layer 30 that is not in contact with the positive electrode active material layer 12. Because the area of ​​the inactive component corrects for the difference between the area of ​​the positive electrode active material layer 12 and the area of ​​the electrolyte layer 30, cracks in the electrolyte layer 30 caused by pressure differences during the pressing process can be effectively suppressed. The inactive component can be disposed between the positive electrode current collector 11 and the electrolyte layer 30 facing each other. The inactive component can serve as a filler to fill the space between the positive electrode current collector 11 and the electrolyte layer 30 facing each other. The inactive component can include at least one selected from lithium-ion insulators and lithium-ion conductors. The inactive component can be an electronic insulator. That is, the inactive component may not be an electronic conductor. The inactive component can be an organic material, an inorganic material, or an organic / inorganic composite material. The organic material can be, for example, a polymer. The inorganic material can be, for example, a ceramic (such as a metal oxide). The organic / inorganic composite material can be a composite of polymers and metal oxides. The inactive component can include, for example, at least one selected from insulating polymers, ion-conducting polymers, insulating inorganic materials, oxide-based solid electrolytes, and sulfide-based solid electrolytes. The inactive component can be, for example, an olefin polymer (such as polypropylene (PP) and polyethylene (PE)). The inactive component can be, for example, a gasket. The thickness of the inactive component can be the same as or similar to the thickness of the positive electrode active material layer 12.

[0091] According to an embodiment, the current density of the positive electrode 10 can be 1 mAh / cm². 2 Up to 20mAh / cm 2 For example, the current density of the positive electrode 10 can be 1.5 mAh / cm³. 2 Up to 20mAh / cm 2 2mAh / cm 2Up to 20mAh / cm 2 1mAh / cm 2 Up to 18mAh / cm 2 1mAh / cm 2 Up to 16mAh / cm 2 1mAh / cm 2 Up to 14mAh / cm 2 1mAh / cm 2 Up to 12mAh / cm 2 1mAh / cm 2 Up to 10mAh / cm 2 or 2mAh / cm 2 Up to 10mAh / cm 2 .

[0092] (Diaphragm) Subsequently, a separator to be inserted between the positive electrode 10 and the negative electrode 20 is prepared.

[0093] Any separator commonly used in the art for lithium-ion batteries can be used. For example, any separator with low resistance to ion migration of the electrolyte and excellent electrolyte retention can be used. For example, the separator can be selected from glass fiber, polyester, Teflon, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), or any combination thereof, which are each nonwoven or woven fabrics. For example, rollable separators comprising polyethylene or polypropylene can be used in lithium-ion batteries, and separators with excellent organic electrolyte retention can be used in lithium-ion polymer batteries.

[0094] The membrane can be prepared according to the exemplary method described below. However, the method is not limited to this and can be adapted to the required conditions.

[0095] First, a polymer resin, filler, and solvent can be mixed to prepare a membrane composition. The membrane composition can then be applied directly to the electrode and dried to prepare a membrane. Alternatively, the membrane composition can be cast onto a support and dried, and then the membrane, separated from the support, can be laminated onto the electrode to form a membrane.

[0096] There are no restrictions on the polymers used to prepare the diaphragm, and any polymer commonly used as a binder for electrode plates can be used. For example, vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, or any mixture thereof can be used.

[0097] (electrolytes) Electrolytes can then be prepared.

[0098] The electrolyte layer 30 may include, for example, a liquid electrolyte, a semi-solid gel electrolyte, a solid electrolyte, or any combination thereof.

[0099] For example, the electrolyte can be an organic electrolyte. Organic electrolytes can be prepared, for example, by dissolving a lithium salt in an organic solvent.

[0100] Any organic solvent commonly used in the art can be used. For example, the organic solvent can be propylene carbonate, ethylene carbonate, fluoroethylene carbonate, butyl carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl isopropyl carbonate, dipropyl carbonate, dibutyl carbonate, benzyl nitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, dioxolane, 4-methyldioxolane, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, 1,2-dimethoxyethane, sulfolane, dichloroethane, chlorobenzene, nitrobenzene, diethylene glycol, dimethyl ether, or any mixture thereof.

[0101] The lithium salt can also be any lithium salt commonly used in the art. For example, the lithium salt can be LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, Li(CF3SO2)2N, LiC4F9SO3, LiAlO2, LiAlCl4, LiN(C x F 2x+1 SO2)(C y F 2y+ Lithium salts can be 1-SO₂ (where 1 ≤ x ≤ 20 and 1 ≤ y ≤ 20), LiCl, LiI, or any mixture thereof. The concentration of the lithium salt can be, for example, from 0.1 M to 5.0 M.

[0102] For example, semi-solid gel electrolytes can be in gel or semi-solid form. Compared to completely solid forms, semi-solid gel electrolytes in gel or semi-solid form allow one or more of lithium metals and lithium alloys to expand freely during charge and discharge, thus overcoming the aforementioned drawbacks of conventional lithium metal batteries.

[0103] For example, a semi-solid gel electrolyte may include one or more selected from lithium metal and lithium alloys, as well as a liquid electrolyte. For example, a semi-solid gel electrolyte can be prepared by supplying a composition for forming a semi-solid gel electrolyte and drying the composition.

[0104] Compositions for forming semi-solid gel electrolytes can be prepared by mixing one or more selected from lithium metal and lithium alloys with a liquid electrolyte. The compositions for forming semi-solid gel electrolytes have a gel or semi-solid form. The viscosity of the compositions for forming semi-solid gel electrolytes at 25°C can be, for example, but not limited to, 5 cP or less, such as 2.5 cP to 4.0 cP.

[0105] The solid electrolyte can be, for example, an oxide-based solid electrolyte, a sulfide-based solid electrolyte, or any combination thereof.

[0106] The solid electrolyte can be, for example, an oxide-based solid electrolyte. The oxide-based solid electrolyte can include, for example, at least one selected from the following: Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (where 0 < x < 2 and 0 ≤ y < 3), BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3 (PLZT, where 0 ≤ x < 1 and 0 ≤ y < 1), Pb(Mg3Nb 2 / 3 )O3 - PbTiO3 (PMN - PT), HfO2, SrTiO3, SnO2, CeO2, Na2O, MgO, NiO, CaO, BaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiO2, Li3PO4, Li x Ti y (PO4)3 (where 0 < x < 2 and 0 < y < 3), Li x Al y Ti z (PO4)3 (where 0 < x < 2, 0 < y < 1 and 0 < z < 3), Li 1+x+y (Al,Ga) x (Ti,Ge) 2-x Si y P 3-y O 12 (where 0 ≤ x ≤ 1 and 0 ≤ y ≤ 1), Li x La y TiO3 (where 0 < x < 2 and 0 < y < 3), Li2O, LiOH, Li2CO3, LiAlO2, Li2O - Al2O3 - SiO2 - P2O5 - TiO2 - GeO2 and Li 3+x La3M2O 12 (where M = Te, Nb or Zr, and x is an integer from 1 to 10). The solid electrolyte can be manufactured by a sintering method or the like. For example, the oxide-based solid electrolyte can be selected from Li7La3Zr2O 12 (LLZO) and Li 3+x La3Zr 2-a M a O 12A garnet-type solid electrolyte in (M-doped LLZO, where M = Ga, W, Nb, Ta or Al, x is an integer from 1 to 10, and 0 < a < 2).

[0107] For example, sulfide-based solid electrolytes can include, for example, lithium sulfide, silicon sulfide, phosphorus sulfide, boron sulfide, or any combination thereof. Sulfide-based solid electrolyte particles can include Li2S, P2S5, SiS2, GeS2, B2S3, or any combination thereof. Sulfide-based solid electrolyte particles can be Li2S or P2S5. It is known that sulfide-based solid electrolyte particles have a higher lithium ion conductivity than other inorganic compounds. For example, sulfide-based solid electrolytes can include Li2S and P2S5. If the sulfide solid electrolyte material constituting the sulfide-based solid electrolyte includes Li2S-P2S5, the mixing molar ratio of Li2S to P2S5 can be, for example, in the range of about 50:50 to about 90:10. Additionally, by adding Li3PO4, halogen atoms, halogen compounds, Li 2+2x Zn 1- x GeO4 (“LISICON”, where 0 ≤ x < 1), Li 3+y PO 4-x N x (“LIPON”, where 0 < x < 4 and 0 < y < 3), Li 3.25 Ge 0.25 P 0.75 S4 (“Thio-LISICON”), Li2O-Al2O3-TiO2-P2O5 (“LATP”), etc. added to an inorganic solid electrolyte (such as Li2S-P2S5, SiS2, GeS2, B2S3, or any combination thereof) can be used as sulfide-based solid electrolytes.

[0108] Sulfide-based solid electrolytes can include, for example, at least one selected from the following: Li2S-P2S5, Li2S-P2S5-LiX (where X is a halogen atom), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (where m and n are positive numbers, and Z is Ge, Zn or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q(Where p and q are positive numbers, and M is P, Si, Ge, B, Al, Ga, or In), Li 7-x PS 6-x Cl x (where 0≤x≤2), Li 7-x PS 6-x Br x (where 0 ≤ x ≤ 2) and Li 7-x PS 6-x I x (Where, 0 ≤ x ≤ 2). Sulfide-based solid electrolytes can be prepared by treating starting materials such as Li₂S and P₂S₅ via melt quenching or mechanical grinding. Heat treatment can be performed after this treatment. The solid electrolyte can be in an amorphous state, a crystalline state, or a mixture thereof. For example, the solid electrolyte may include, for example, sulfur (S), phosphorus (P), and lithium (Li) as components in the materials used in the aforementioned sulfide-based solid electrolytes. For example, the solid electrolyte may be a material comprising Li₂S-P₂S₅. When using a material comprising Li₂S-P₂S₅ as the sulfide-based solid electrolyte material constituting the solid electrolyte, the molar ratio of Li₂S to P₂S₅ can be, for example, from 50:50 to 90:10.

[0109] Sulfide solid electrolytes can include, for example, sulfide-germanium ore type solid electrolytes represented by Formula 1 below: <Formula 1> Li + 12-n-x A n+ X 2- 6-x Y - x In Formula 1, A is P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, or Ta; X is S, Se, or Te; and Y is Cl, Br, I, F, CN, OCN, SCN, or N3, wherein 1 ≤ n ≤ 5 and 0 ≤ x ≤ 2. The sulfide solid electrolyte can be a sulfide-germanium ore type compound, for example, selected from at least one of the following: Li 7-x PS 6-x Cl x (where 0≤x≤2), Li 7-x PS 6-x Br x (where 0 ≤ x ≤ 2) and Li 7-x PS 6-x I x (Where, 0 ≤ x ≤ 2). Sulfide solid electrolytes can be sulfide-germanium ore type compounds, including, for example, at least one selected from Li6PS5Cl, Li6PS5Br and Li6PS5I.

[0110] Australite-type solid electrolytes can have densities ranging from 1.5 g / cc to 2.0 g / cc. Because australite-type solid electrolytes have densities of 1.5 g / cc or higher, they can reduce the internal resistance of all-solid-state lithium metal batteries and effectively suppress Li penetration of the solid electrolyte layer.

[0111] Sulfide-based solid electrolytes can have, for example, an elastic modulus (i.e., Young's modulus) of 35 GPa or less, 30 GPa or less, 27 GPa or less, 25 GPa or less, or 23 GPa or less. Sulfide-based solid electrolytes can also have, for example, an elastic modulus (i.e., Young's modulus) of 10 GPa to 35 GPa, 10 GPa to 30 GPa, 10 GPa to 27 GPa, 10 GPa to 25 GPa, or 10 GPa to 23 GPa. Because sulfide-based solid electrolytes have elastic moduli within the above ranges, the temperature and / or pressure required for sintering are reduced, thus making the sintering of solid electrolytes easier.

[0112] The solid electrolyte used in the electrolyte layer 30 may have an average particle size (D50) of, for example, 1 μm to 10 μm, 1.5 μm to 7 μm, or 2 μm to 5 μm.

[0113] Based on the total weight of the electrolyte layer 30, the amount of sulfide-based solid electrolyte included in the electrolyte layer 30 may be, for example, 97 wt% to 100 wt%, 98 wt% to 99.9 wt%, or 98.5 wt% to 99.0 wt%.

[0114] For example, the electrolyte layer 30 may also include an adhesive. The adhesive included in the electrolyte layer 30 may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, or polyethylene, but is not limited thereto, and any adhesive commonly available in the art may be used. The adhesive of the electrolyte layer 30 may be the same as or different from the adhesive included in the positive electrode active material layer 12 and the negative electrode active material layer 220.

[0115] Based on the total weight of the electrolyte layer 30, the amount of binder included in the electrolyte layer 30 may be, for example, 0.1 wt% to 3 wt%, 0.5 wt% to 2 wt%, or 1.0 wt% to 2.0 wt%.

[0116] For example, a lithium metal battery 1 includes an electrolyte layer 30, a positive electrode 10 disposed on one side of the electrolyte layer 30, and a negative electrode 20 disposed on the other side of the electrolyte layer 30. The positive electrode 10 may include a positive active material layer 12 in contact with the electrolyte layer 30 and a positive current collector 11 in contact with the positive active material layer 12. The negative electrode 20 may include a negative active material layer in contact with the electrolyte layer 30 and a negative current collector in contact with the negative active material layer 220. For example, an all-solid-state lithium metal battery 1 can be fabricated by disposing the positive active material layer 12 and the negative active material layer on both sides of the electrolyte layer 30, and by disposing the positive current collector 11 and the negative current collector on the positive active material layer 12 and the negative active material layer 220, respectively. Optionally, an all-solid-state lithium metal battery 1 can be fabricated by sequentially stacking the negative active material layer, the electrolyte layer 30, the positive active material layer 12, and the positive current collector 11 on the negative current collector.

[0117] (Lithium metal battery) Reference Figure 5 The lithium metal battery 1 according to an embodiment includes a positive electrode 3, the aforementioned negative electrode 2, and a separator 4. The positive electrode 3, negative electrode 2, and separator 4 can be wound or stacked to form a battery assembly 7. The formed battery assembly 7 can be housed in a battery casing 5. An organic electrolyte is injected into the battery casing 5, and the battery casing 5 is sealed with a cover assembly 6 to complete the fabrication of the lithium metal battery 1. The battery casing 5 can have a cylindrical shape, but is not limited thereto, and can have, for example, a rectangular shape or a thin film shape.

[0118] Reference Figure 4 The lithium metal battery 1 according to an embodiment includes a positive electrode 3, the aforementioned negative electrode 2, and a separator 4. The separator 4 may be disposed between the positive electrode 3 and the negative electrode 2, and the positive electrode 3, the negative electrode 2, and the separator 4 may be wound or folded to form a battery assembly 7. The formed battery assembly 7 may be housed in a battery casing 5. The lithium metal battery 1 may include electrode terminals 8 serving as electrical channels for guiding the current generated in the battery assembly 7 to the outside. An organic electrolyte is injected into the battery casing 5 and the battery casing 5 is sealed to complete the fabrication of the lithium metal battery 1. The battery casing 5 may have a rectangular shape, but is not limited thereto, and may also have, for example, a cylindrical shape or a thin film shape.

[0119] Reference Figure 6The lithium metal battery 1 according to an embodiment includes a positive electrode 3, the aforementioned negative electrode 2, and a separator 4. The separator 4 may be disposed between the positive electrode 3 and the negative electrode 2 to form a battery assembly. The battery assembly 7 may be stacked in a dual-cell structure and housed in a battery casing 5. The lithium metal battery 1 may include electrode terminals 8 serving as electrical channels for guiding the current generated in the battery assembly 7 to the outside. An organic electrolyte is injected into the battery casing 5 and the battery casing 5 is sealed to complete the fabrication of the lithium metal battery 1. The battery casing 5 may have a rectangular shape, but is not limited thereto, and may also have, for example, a cylindrical shape or a thin-film shape.

[0120] In pouch-type lithium metal batteries, the pouch can be used as... Figures 4 to 6 The diagram shows the battery casing of a lithium metal battery. A pouch-type lithium metal battery includes at least one battery assembly. A separator can be disposed between the positive and negative electrodes to form the battery assembly. The battery assembly is stacked in a dual-cell structure, impregnated with an organic electrolyte, housed in a pouch, and sealed to complete the fabrication of the pouch-type lithium metal battery. For example, although not shown in the figures, the aforementioned positive, negative, and separator components can be simply stacked into a battery assembly and housed in a pouch, or wound or folded in the form of electrode cores into a battery assembly and housed in a pouch. Subsequently, an organic electrolyte can be injected into the pouch and the pouch can be sealed to complete the fabrication of the lithium metal battery.

[0121] Due to their excellent lifespan and high-rate characteristics, lithium metal batteries can be used in applications such as electric vehicles (EVs). For example, lithium metal batteries can be used in hybrid vehicles (such as plug-in hybrid electric vehicles (PHEVs)). Additionally, lithium metal batteries can be used in applications requiring large amounts of energy storage. For example, lithium metal batteries can be used in electric bicycles and power tools.

[0122] Multiple lithium metal batteries can be stacked to form a battery module, and multiple battery modules constitute a battery pack. This battery pack can be used in any device requiring high capacity and high output. For example, the battery pack can be used in laptops, smartphones, and electric vehicles. For example, a battery module may include multiple batteries and a frame to hold the batteries. The battery pack may include, for example, multiple battery modules and busbars connecting the battery modules. The battery modules and / or the battery pack may also include a cooling device. Multiple battery packs can be controlled by a battery management system. The battery management system may include the battery pack and battery control devices connected to the battery pack.

[0123] [Methods for manufacturing the negative electrode] A method for manufacturing the negative electrode 20 according to an embodiment may include: preparing a negative electrode structure, the negative electrode structure including a negative electrode current collector 210, a negative electrode active material layer 220 disposed on the negative electrode current collector 210, and a porous layer 230 disposed on the negative electrode active material layer 220; and inserting at least a portion of the porous layer 230 into the negative electrode active material layer 220 by rolling the negative electrode structure via a roller press.

[0124] For example, the preparation of the negative electrode structure may include preparing a negative electrode current collector 210, preparing a negative electrode active material layer 220 on the negative electrode current collector 210, and preparing a porous layer 230 on the negative electrode active material layer 220.

[0125] For example, the negative electrode current collector 210, the negative electrode active material layer 220, and the porous layer 230 are as described above.

[0126] For example, at least a portion of the porous layer 230 can be inserted into the negative electrode active material layer 220 by rolling the negative electrode structure through a roller press. For example, the roller press may include multiple rollers, and the porous layer can be inserted into the negative electrode active material layer by inserting the negative electrode structure into the multiple rollers. For example, the degree to which the porous layer 230 is inserted into the negative electrode active material layer 220 can be adjusted by controlling the gap between the multiple rollers. For example, the degree to which the porous layer 230 is inserted into the negative electrode active material layer 220 can be controlled by adjusting the pressure applied to the negative electrode structure.

[0127] The inventive concept will be described in more detail below with reference to the following examples and comparative examples. However, these examples are not intended to limit the purpose and scope of the inventive concept.

[0128] (Manufacturing of lithium metal batteries) Example 1: Cu substrate / Li foil / Cu foam (porosity 80%), H=100% (Preparation of the positive electrode) LiNi will be used as the positive electrode active material 0.8 Mn 0.1 Co 0.1 O2, carbon conductive material (Denka Black), and polyvinylidene fluoride (PVdF) were mixed in a weight ratio of 96:2:2, and the mixture was then mixed with N-methylpyrrolidone (NMP) in an agate mortar to prepare a slurry.

[0129] By using slurry at 8.5 mg / cm 2 The electrode was loaded onto a 15 μm thick aluminum current collector and dried at room temperature for rod coating, then dried again under vacuum at 120 °C, followed by rolling and stamping to produce a positive electrode plate with a thickness of 21 μm and an electrode density of 4.1 g / cc.

[0130] The current density at the positive electrode is 6 mAh / cm². 2 .

[0131] (Preparation of the negative electrode) A 20 μm thick lithium (Li) foil was attached to a 10 μm thick copper (Cu) current collector. A 50 μm thick Cu foam with 80% porosity was prepared and deposited on the Li foil to fabricate the negative electrode structure. Surface analysis of the Cu foam by X-ray photoelectron spectroscopy (XPS) showed an oxide peak to metal peak ratio of 4:1.

[0132] By inserting the negative electrode structure into the rolling mill, Cu foam is inserted into 70% of the total thickness of the Li foil. In this case, the value of Expression 1 below is 36.7 μm, and the thickness (H) of the Cu foam not inserted into the lithium foil (first region) is 100% of the value calculated by Expression 1.

[0133] <Expression 1> Positive electrode current density (mAh / cm²) 2 )×4.89µm / (mAh / cm 2 )×(1 / porosity of the first region) (Manufacturing of lithium metal batteries) A lithium metal battery is manufactured by using the positive and negative electrode plates prepared above, a PTFE separator, and a solution as an electrolyte prepared by dissolving 1.3M LiPF6 in a mixed solvent of ethylene carbonate (EC), ethyl propionate (EP), and propyl propionate (PP) in a volume ratio of 25:30:45.

[0134] Example 2: Cu substrate / Li foil / Cu foam (porosity 80%), H=130% The lithium metal battery is manufactured in the same manner as in Example 1, except that the thickness (H) of the Cu foam (first region) not inserted into the Li foil is 130% of the value of Expression 1 compared to Example 1.

[0135] Example 3: Cu substrate / Li foil / Cu foam (porosity 80%), H=50% The lithium metal battery is manufactured in the same manner as in Example 1, except that the thickness of the Cu foam not inserted into the Li foil is 50% of the value of Expression 1, compared to Example 1.

[0136] Example 4: Cu substrate / Li foil / Cu foam (porosity 80%), H=160% The lithium metal battery is manufactured in the same manner as in Example 1, except that the thickness of the Cu foam not inserted into the Li foil is 160% of the value of Expression 1 compared to Example 1.

[0137] Example 5: Cu substrate / Li foil / acid-treated Cu foam (porosity 80%), H=100% The lithium metal battery was manufactured in the same manner as in Example 1, except that the Cu foam treated with hydrochloric acid was used, as in Example 1. As a result of surface analysis of the hydrochloric acid-treated Cu foam by X-ray photoelectron spectroscopy (XPS), the ratio of oxide peaks to metal peaks was 11:1.

[0138] Example 6: Cu substrate / Li foil / Cu foam (porosity 50%), H=100% The lithium metal battery is manufactured in the same manner as in Example 1, except that a Cu foam with a porosity of 50% is used, compared to Example 1.

[0139] Comparison Example 1: Cu substrate / Cu foam (porosity 80%) The lithium metal battery is manufactured in the same manner as in Example 1, except that the Cu foam is directly attached to the negative electrode current collector instead of the Li foil, as in Example 1.

[0140] Comparative Example 2: Cu substrate / Li foil / Cu foam (porosity 80%) The lithium metal battery is manufactured in the same manner as in Example 1, except that the Cu foam is not inserted into the negative electrode active material layer, unlike in Example 1.

[0141] Evaluation Example 1: Evaluation of charge / discharge characteristics at room temperature Each of the lithium metal batteries prepared in Examples 1 to 6 and Comparative Examples 1 to 2 was charged at 25°C with a constant current at a rate of 0.1C until the voltage reached 4.55V (relative to Li), and the charging process was stopped in constant voltage mode with a current at a rate of 0.05C while maintaining the voltage at 4.55V. Subsequently, the lithium metal battery was discharged at a constant current at a rate of 0.1C until the voltage reached 3.0V (relative to Li) during the discharge (formation cycle).

[0142] The lithium metal battery, which had already undergone formation cycling, was charged at 25°C with a constant current at a rate of 0.2C until the voltage reached 4.55V (relative to Li). Then, the charging process was stopped at a rate of 0.05C in constant voltage mode while maintaining the voltage at 4.55V. Subsequently, during discharge, the lithium metal battery was discharged at a constant current at a rate of 0.2C until the voltage reached 3.0V (relative to Li) (first cycle). In this regard, the DC internal resistance (DC-IR) was calculated by measuring the voltage drop (V) caused by supplying a 1C current for 1 second at a SOC of 10 (where it is assumed that the battery's full charge capacity is 100%, and the battery is charged to have 10% charge capacity, i.e., when observed in the discharge state, the battery is 90% discharged).

[0143] The lithium metal battery, having undergone its first cycle, was charged at 25°C with a constant current at a 1C rate until the voltage reached 4.55V (relative to Li). Then, the charging process was stopped in constant voltage mode with a current at a 0.05C rate while maintaining the voltage at 4.55V. Subsequently, the lithium metal battery was discharged at a constant current at a 1C rate until the voltage reached 3.0V (relative to Li) (second cycle). This charge / discharge cycle was repeated under the same conditions until the 200th cycle. The capacity retention was calculated for each 200 cycles.

[0144] After each charge / discharge cycle, let the lithium metal battery rest for 10 minutes.

[0145] The number of cycles required to achieve an initial efficiency of 0.2C (%) and a capacity retention of 80% in the room temperature charge-discharge results is shown in Table 1 below. The capacity retention (%) for each cycle is defined by Equation 1 below.

[0146] Equation 1 Capacity retention rate [%] = [Discharge capacity per cycle / Discharge capacity in the first cycle] × 100 Table 1

[0147] As shown in Table 1, compared with the lithium metal batteries of Comparative Examples 1 to 2, the lithium metal batteries of Examples 1 to 6 have lower DC-IR and improved lifespan.

[0148] Although embodiments have been described above with reference to the accompanying drawings, the inventive concept is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications will be readily apparent within the scope of the inventive concept.

[0149] Explanation of reference numerals indicating the main elements of the accompanying drawings 1. Lithium metal battery; 2. 20 negative electrode 3. 10 Positive electrode; 4 Separator 5. Battery casing; 6. Cover assembly 7. Battery assembly; 8. Electrode terminals 11 Positive current collector; 12 Positive active material layer 20 negative electrode; 30 electrolyte layer 210 negative electrode current collector; 220 negative electrode active material layer 230 porous layer; 240 lithium coating A1 First Area; A2 Second Area A3, Area 3.

Claims

1. A lithium metal battery, the lithium metal battery comprising: positive electrode; negative electrode; And an electrolyte, disposed between the positive electrode and the negative electrode. The negative electrode comprises: a negative electrode current collector; a negative electrode active material layer disposed on the negative electrode current collector; and a porous layer comprising a porous structure. The porous layer includes a first region exposed on the negative electrode active material layer and a second region inserted into the negative electrode active material layer, and The negative electrode active material layer includes a second region in which the porous layer is inserted and a third region in which the porous layer is not inserted.

2. The lithium metal battery according to claim 1, in, The thickness of the first region satisfies 100% to 130% of the following expression 1: Expression 1 Positive electrode current density (mAh / cm) 2 )×4.89µm / (mAh / cm 2 )×(1 / porosity of the first region).

3. The lithium metal battery according to claim 1, in, The lithium coating is formed on the negative electrode active material layer by charging the lithium metal battery, and The thickness of the lithium plating is 130% or less of the thickness of the first region.

4. The lithium metal battery according to claim 1, in, The porous layer, including the porous structure in the first region, has a porosity of 1% to 99%.

5. The lithium metal battery according to claim 1, in, The porous layer includes pores with sizes ranging from 1 nm to 10 μm in the first region.

6. The lithium metal battery according to claim 1, in, The thickness of the first region of the porous layer is 1 μm to 100 μm, and The thickness of the second region of the porous layer is 1 μm to 50 μm.

7. The lithium metal battery according to claim 1, in, The thickness of the second region is 70% or less of the thickness of the negative electrode active material layer.

8. The lithium metal battery according to claim 1, in, The hardness of the porous layer is greater than that of the negative electrode active material layer.

9. The lithium metal battery according to claim 1, in, The porous layer comprises a metallic or carbonaceous material, and The metals include copper, nickel, stainless steel, iron, or cobalt.

10. The lithium metal battery according to claim 1, in, The porous structure includes a foam structure or a mesh structure.

11. The lithium metal battery according to claim 1, in, The porous structure was treated with acid.

12. The lithium metal battery according to claim 1, in, As analyzed by X-ray photoelectron spectroscopy, the acid-treated porous structure has an oxide peak to metal peak ratio of 50:1 to 1:

1.

13. The lithium metal battery according to claim 1, The lithium metal battery also includes a coating layer formed on the surface of the porous structure.

14. The lithium metal battery according to claim 1, in, The negative electrode active material layer includes lithium metal or lithium alloy.

15. The lithium metal battery according to claim 1, in, The thickness of the third region of the negative electrode active material layer is 0.1 μm to 10 μm.

16. The lithium metal battery according to claim 1, in, The negative electrode current collector can be selected from sheets, foils, films, plates, porous structures, mesoporous structures, structures with through holes, polygonal rings, meshes, foams, and nonwoven structures.

17. The lithium metal battery according to claim 1, in, The negative electrode current collector includes a base film and a metal layer disposed on one or both sides of the base film. The base film comprises a polymer, which includes polyethylene terephthalate, polyethylene, polypropylene, polybutylene terephthalate, polyimide, or combinations thereof. The metal layer includes indium, copper, magnesium, titanium, iron, cobalt, nickel, zinc, aluminum, germanium, lithium, or alloys thereof.

18. The lithium metal battery according to claim 1, in, The current density of the positive electrode is 1 mAh / cm². 2 Up to 20mAh / cm 2 .

19. The lithium metal battery according to claim 1, in, The electrolyte includes liquid electrolytes, semi-solid gel electrolytes, solid electrolytes, or combinations thereof.

20. A method for manufacturing the negative electrode of the lithium metal battery according to claim 1, the method comprising the following steps: A negative electrode structure is prepared, the negative electrode structure comprising a negative electrode current collector, a negative electrode active material layer disposed on the negative electrode current collector, and a porous layer disposed on the negative electrode active material layer; and At least a portion of the porous layer is inserted into the negative electrode active material layer by rolling the negative electrode structure with a roller press.

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