Negative electrode for lithium metal battery, method for manufacturing same, and lithium metal battery comprising same

Abstract

Disclosed are a negative electrode for a lithium metal battery, a lithium metal battery comprising same, and a method for manufacturing same, the negative electrode comprising: a negative electrode current collector; a host layer containing meso-carbon micro-beads disposed on the negative electrode current collector; a first MCMB-containing layer containing MCMB and a first lithium ion conductive polymer; and a second MCMB-containing layer containing MCMB and a second lithium ion conductive polymer, wherein the first lithium ion conductive polymer and the second lithium ion conductive polymer have an electrical conductivity of 10-8 S / m or less, and the content of the second lithium ion conductive polymer is larger than the content of the first lithium ion conductive polymer.

Description

Anode for lithium metal battery, method for manufacturing same, and lithium metal battery including same

[0001] The present invention relates to a negative electrode for a lithium metal battery, a method for manufacturing the same, and a lithium metal battery including the same.

[0002] Lithium-ion batteries currently on the market primarily use carbon-based anode materials, such as graphite. Carbon-based anode materials exhibit no volume change during charge / discharge, contributing to the stability of lithium-ion batteries. However, their low capacity necessitates the use of higher-capacity anode materials.

[0003] Lithium metal, which has a much larger theoretical electric capacity than carbon-based negative electrode materials, can be used as a negative electrode material.

[0004] When lithium metal is charged and discharged, dendrites are formed on the surface of the lithium metal due to a side reaction with the electrolyte, and the growth of the dendrites can cause a short circuit between the positive and negative electrodes, which can reduce the life characteristics of a lithium metal battery containing lithium metal.

[0005] A method for improving the life characteristics of a lithium metal battery containing lithium metal is required.

[0006] One aspect is to provide a negative electrode for a lithium metal battery capable of controlling the volume change of lithium metal that occurs during charging and discharging.

[0007] Another aspect is to provide a lithium metal battery having improved Coulomb efficiency, including the above-described negative electrode.

[0008] Another aspect is to provide a method for manufacturing the above-described negative electrode for a lithium metal battery.

[0009] According to the implementation example

[0010] negative current collector;

[0011] Mesocarbon microbeads located on the above negative electrode collector:

[0012] Host layer containing MCMB);

[0013] A first MCMB-containing layer containing MCMB and a first lithium ion conductive polymer, and a second MCMB-containing layer containing MCMB and a first lithium ion conductive polymer.

[0014] A second MCMB containing layer containing a lithium ion conductive polymer, wherein the first lithium ion conductive polymer and the second lithium ion conductive polymer have an electrical conductivity of 10 -8 S / m or less, and a negative electrode for a lithium metal battery is provided in which the content of the second lithium ion conductive polymer is greater than the content of the first lithium ion conductive polymer.

[0015] Bipolar according to other aspects;

[0016] The above-mentioned cathode; and

[0017] A lithium metal battery is provided including an electrolyte disposed between the positive electrode and the negative electrode.

[0018] Another aspect is the step of preparing a cathode current collector;

[0019] A step of forming a host layer on a negative electrode collector;

[0020] A step of electrospraying a composition containing MCMB and a first lithium ion conductive polymer;

[0021] A step of electrospraying a composition containing MCMB and a second lithium ion conductive polymer, and then drying the composition,

[0022] The above first lithium ion conductive polymer and the second lithium ion conductive polymer

[0023] Electrical conductivity is 10 -8 S / m or less,

[0024] A method for manufacturing a negative electrode for a lithium metal battery is provided, wherein the content of the second lithium ion conductive polymer is controlled to be greater than the content of the first lithium ion conductive polymer, thereby manufacturing the above-described negative electrode.

[0025] The above electrospraying is electrospinning or electrospraying.

[0026] According to one aspect, a lithium metal battery containing a negative electrode in which volume change of lithium metal and electrodeposition into a dendrite are controlled is provided.

[0027] Figure 1a is a scanning electron microscope analysis photograph showing the formation of a lithium electrodeposition layer on the negative electrode for a lithium metal battery of Example 1.

[0028] Figure 1b is a scanning electron microscope analysis photograph showing the formation of a lithium deposition layer on the negative electrode for a lithium metal battery of Comparative Example 1.

[0029] Figure 2 shows a capacity-voltage graph for the lithium metal batteries of Example 1 and Comparative Example 1.

[0030] Figure 3 is a schematic diagram of a lithium metal battery according to an embodiment.

[0031] Figure 4 is a schematic diagram of a lithium metal battery according to another embodiment.

[0032] Figure 5 is a schematic diagram of a lithium metal battery according to another embodiment.

[0033] Figure 6 is a schematic diagram of a lithium metal battery according to another embodiment.

[0034] <Brief explanation of drawing symbols>

[0035] 1 Lithium metal battery 2, 20 cathode

[0036] 3, 10 anode 4 separator

[0037] 5 Battery case 6 Cap assembly

[0038] 7 Battery structure 8 Electrode tab

[0039] The present inventive concept described below is capable of various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present inventive concept to specific embodiments, and should be understood to encompass all modifications, equivalents, or alternatives within the technical scope of the present inventive concept.

[0040] The terminology used below is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. Hereinafter, the terms "comprises" or "has" and the like are intended to indicate the presence of a feature, number, step, operation, component, part, ingredient, material, or combination thereof described in the specification, but should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, ingredients, materials, or combinations thereof. The " / " used below may be interpreted as "and" or "or" depending on the context.

[0041] In order to clearly express various layers and regions in the drawings, the thickness is shown enlarged or reduced. Similar parts are designated by the same drawing reference numerals throughout the specification. When a part such as a layer, film, region, or plate is said to be "on" or "above" another part throughout the specification, this includes not only cases where it is directly above the other part, but also cases where there is another part in between. Terms such as first, second, etc. may be used throughout the specification to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. In this specification and the drawings, components having substantially the same functional configuration are referred to by the same reference numerals, and redundant descriptions are omitted.

[0042] Unless otherwise specified herein, when a part such as a layer, film, region, or plate is said to be “on top of” another part, this includes not only cases where it is “directly on top of” the other part, but also cases where there is another part in between.

[0043] Unless otherwise specified herein, the singular may also include the plural. Furthermore, unless otherwise specified, "A or B" may mean "including A, including B, or including A and B."

[0044] As used herein, “combination thereof” may mean mixtures, laminates, composites, copolymers, alloys, blends, and reaction products of the components.

[0045] Unless otherwise defined herein, the particle size may be the average particle size. In addition, the particle size refers to the average particle size (D50), which means the diameter of particles with a cumulative volume of 50% by volume in a particle size distribution. The average particle size (D50) can be measured by a method well known to those skilled in the art, for example, by measuring with a particle size analyzer, or by measuring with a transmission electron microscope (TEM) photograph or a scanning electron microscope (SEM) photograph. Alternatively, the average particle size (D50) value can be obtained by measuring with a measuring device that utilizes dynamic light-scattering, performing data analysis to count the number of particles for each particle size range, and calculating from the counted number. Alternatively, the average particle size (D50) value can be obtained by measuring with a laser diffraction method. When measuring by laser diffraction, more specifically, after the particles to be measured are dispersed in a dispersion medium, they are introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiated with ultrasonic waves of approximately 28 kHz at an output of 60 W, and the average particle size (D50) based on 50% of the particle size distribution in the measuring device can be calculated.

[0046] In this disclosure, “metal” includes both metals and metalloids such as silicon and germanium, in their elemental or ionic states.

[0047] In this disclosure, “alloy” means a mixture of two or more metals.

[0048] In the present disclosure, “positive electrode material” means a positive electrode material capable of undergoing lithiation and delithiation.

[0049] In the present disclosure, “negative electrode active material” means a negative electrode material capable of undergoing lithiation and delithiation.

[0050] In the present disclosure, “lithiation” and “lithiating” mean a process of adding lithium to a positive electrode active material or a negative electrode active material.

[0051] In the present disclosure, “delithiation” and “delithiate” mean a process of removing lithium from a positive electrode active material or a negative electrode active material.

[0052] In this disclosure, “charging” and “charging” mean a process of providing electrochemical energy to a battery.

[0053] In this disclosure, “discharging” and “discharging” mean the process of removing electrochemical energy from a battery.

[0054] In the present disclosure, “positive electrode” and “cathode” mean an electrode at which electrochemical reduction and lithiation occur during a discharge process.

[0055] In the present disclosure, “cathode” and “anode” mean electrodes where electrochemical oxidation and delithiation occur during a discharge process.

[0056] In the present disclosure, thickness refers to, for example, an average thickness. The thickness can be evaluated using a scanning electron microscope. In the present disclosure, the porosity of the negative electrode, the host layer, the first MCMB-containing layer, and the second MCMB-containing layer in a lithium metal battery can be analyzed using a scanning electron microscope (SEM). The volume occupied by the pores can be examined using a SEM, and then the porosity can be measured.

[0057] The term “lithium-substitutable functional group” refers to a functional group that has a high affinity for lithium ions and one pair of electrons.

[0058] Hereinafter, a negative electrode for a lithium metal battery, a lithium metal battery including the same, and a method for manufacturing the negative electrode for a lithium metal battery according to exemplary embodiments are described in more detail.

[0059] A non-cathode lithium metal battery is a battery that uses only a cathode current collector without a cathode active material layer. When charging, lithium ions transferred from the cathode are deposited on the surface of the cathode current collector, and when discharging, the lithium deposited on the cathode current collector is eluted again and inserted into the cathode, thereby operating the battery.

[0060] Non-cathode lithium metal batteries offer the advantage of maximizing energy density per volume / weight of the battery by omitting lithium metal as the anode active material. However, lithium metal precipitates during operation, and the uneven current concentration during oxidation / reduction causes lithium dendrites to grow. These dendrites not only cause lithium anode loss, reducing battery capacity and lifespan, but can also cause short-circuiting between the anode and cathode, posing safety concerns.

[0061] To solve the above-mentioned problems, a method has been proposed to minimize the contact between lithium and electrolyte and thereby reduce side reactions by introducing a protective layer on top of the negative electrode current collector to minimize exposure of the electrolyte on the electrode surface and create a uniform flow of lithium ions throughout the electrode, thereby suppressing lithium dendrite growth. Alternatively, a method has been proposed to introduce a host material that acts as a framework for lithium electrodeposition and structurally controls the growing lithium. However, when an electrically conductive material is used as a host, a top deposition phenomenon may occur, in which lithium cannot smoothly enter the structure and accumulates at the top. If lithium deposition occurs on top of the host layer with a three-dimensional structure like this, it can cause problems such as wasting the internal space of the host layer and failing to control the shape of the lithium metal, and thus improvements are required.

[0062] In order to solve the above-described problem, a negative electrode for a lithium metal battery according to an embodiment comprises: a negative electrode current collector; a host layer containing mesocarbon microbeads (MCMB) positioned on the negative electrode current collector; a first MCMB-containing layer containing MCMB and a first lithium ion conductive polymer; and a second MCMB-containing layer containing MCMB and a second lithium ion conductive polymer, wherein the first lithium ion conductive polymer and the second lithium ion conductive polymer have an electrical conductivity of 10 -8 S / m or less, and the content of the second lithium ion conductive polymer is greatly controlled compared to the content of the first lithium ion conductive polymer.

[0063] When the content of the second lithium ion conductive polymer is adjusted to be greater than the content of the first lithium ion conductive polymer, lithium is densely deposited inside the host, and the volume change of lithium metal and the deposition into the dendrite that occur during charging / discharging of a lithium metal battery can be effectively controlled.

[0064] The MCMB concentration of the first MCMB-containing layer is different from the MCMB concentration of the second MCMB-containing layer. For example, the MCMB concentration of the first MCMB-containing layer is higher than the MCMB concentration of the second MCMB-containing layer.

[0065] The above negative electrode can be manufactured by sequentially electrospraying solutions having different weight ratios of MCMB and lithium ion conductive polymer on top of the negative electrode current collector to form a three-layer coating layer in which the ratio of the lithium ion conductive polymer, which is a non-conductor, increases as it gets farther from the negative electrode current collector, thereby lowering the electrical conductivity.

[0066] A host structure according to one embodiment includes a host layer, a first MCMB-containing layer, and a second MCMB-containing layer. The host structure is composed of a host layer having a lower portion having high electrical conductivity through MCMB, a first MCMB-containing layer, and a second MCMB-containing layer having low electrical conductivity due to PAN electrospun fibers. Through this, when lithium metal electrodeposition occurs after a lithium ion insertion reaction into MCMB, lithium metal electrodeposition can be induced from the lower portion of the host structure in a bottom-up direction. In addition, since PAN contains a nitrile group with good affinity for lithium ions in its molecule, it forms a uniform lithium metal electrodeposition form. Therefore, a host structure for a lithium metal battery can be manufactured that enables lithium metal electrodeposition in a stable form without a dendrite while increasing the utilization of the internal structure of the host structure, and enables a higher energy density than existing lithium ion batteries.

[0067] The first lithium ion conductive polymer and the second lithium ion conductive polymer have an electrical conductivity of, for example, 10 -8 S / m or less, for example 10 -10 10 inland -8 It is S / m and may have a lithium-substitutable functional group. Examples of lithium-substitutable functional groups include a nitrile group and an ether group.

[0068] The first lithium ion conductive polymer and the second lithium ion conductive polymer are each polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), or a combination thereof.

[0069] For example, the active material layer may be substantially free of carbon-based negative electrode active material, with carbon-based negative electrode active material present, or, if present, only as a secondary impurity. In some embodiments, the active material layer may be completely free of carbon-based negative electrode active material.

[0070] The content of the first lithium ion conductive polymer is 100% of the total weight of the first MCMB containing layer.

[0071] Based on the weight part, it is 3 to 20 parts by weight, 5 to 20 parts by weight, 5 to 15 parts by weight, 5 to 10 parts by weight, for example, 6 to 10 parts by weight.

[0072] In the present disclosure, the content of the second lithium ion conductive polymer is 5 to 30 parts by weight, 10 to 30 parts by weight, 10 to 25 parts by weight, 10 to 20 parts by weight, 10 to 18 parts by weight, for example, 12 to 17 parts by weight, based on 100 parts by weight of the total weight of the second MCMB-containing layer. When the content of the first lithium ion conductive polymer in the first MCMB-containing layer and the content of the second lithium ion conductive polymer in the second MCMB-containing layer are within the above ranges, lithium metal can be electrodeposited in a stable form without a dendrite while increasing the utilization of the internal structure of the host structure, and a lithium metal battery with improved energy density can be manufactured.

[0073] The thickness of the host layer is 10 to 60 um, 15 to 55 um, 20 to 50 um, or 20 to 40 um. The thickness of the first MCMB-containing layer is 5 to 30 um, and the thickness of the second MCMB-containing layer is 5 to 30 um. The thickness ratio of the host layer and the first MCMB-containing layer is 5:1 to 1:1, 4.5:1 to 1:1, 4:1 to 1:1, 3.5:1 to 1:1, or 3:1 to 1:1. The thickness ratio of the host layer and the second MCMB-containing layer is 5:1 to 1:1, 4.5:1 to 1:1, 4:1 to 1:1, 3.5:1 to 1:1, or 3:1 to 1:1. Within this thickness range, a lithium metal battery having excellent energy density and improved high-rate characteristics and life cycle characteristics can be manufactured without increasing internal resistance and reducing the energy density of the lithium metal battery.

[0074] In the present disclosure, the size of MCMB is 1 to 50 μm, and the specific surface area is 0.2 to 5 m 2 / g, 0.3 to 4 m 2 / g, 0.5 to 3 m 2 / g or 0.8 to 2 m 2 / g, and the true density is 2.10g / cm 3 Above, 2.20g / cm 3 Above, 2.2 to 3 g / cm 3 . And MCMB is a mesophase spherical graphite particle with an average circularity of 0.920 to 0.950, or 0.92 to 0.94. When the size, specific surface area, and true density of MCMB are within the above ranges, it has an excellent ability to accommodate electrodeposited lithium. Here, the specific surface area is measured by the BET method.

[0075] Lithium metal may be included in the host layer, between the host layer and the first MCMB layer, the second MCMB layer, or a combination thereof.

[0076] In an embodiment of the negative electrode, the host layer includes a binder. The binder may be selected from the group consisting of carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, or a combination thereof.

[0077] The content of MCMB is 85 to 97 parts by weight, 88 to 96 parts by weight, or 90 to 95 parts by weight based on 100 parts by weight of the total weight of the host layer. When the content of MCMB is within the above range, when lithium metal electrodeposition occurs after a lithium ion insertion reaction, lithium metal electrodeposition can be effectively induced.

[0078] The porosity of the negative electrode is 50 to 70%, or 55 to 65%, the porosity of the host layer is 50 to 60%, or 52 to 58%, the porosity of the first MCMB-containing layer is 55 to 65%, or 58 to 62%, and the porosity of the second MCMB-containing layer is 65 to 75%, or 68 to 73%. When the porosities of the negative electrode, the host layer, the first MCMB-containing layer, and the second MCMB-containing layer are within the above ranges, the storage capacity of the electrodeposited lithium is improved.

[0079] The first lithium ion conductive polymer and the second lithium ion conductive polymer are formed by electrospraying such as electrospinning, and each has an average diameter of 0.001 nm to 1000 nm, 0.01 nm to 800 nm, 0.01 nm to 700 nm, 0.01 nm to 500 nm, 50 nm to 500 nm, or 100 to 500 nm. When the first lithium ion conductive polymer and the second lithium ion conductive polymer have the above-described average diameter, lithium metal can be electrodeposited in a stable form without a dendrite, and a lithium metal battery with improved energy density can be manufactured.

[0080] A lithium electrodeposition induction layer, a protective layer, or a combination thereof may be further included between the negative electrode current collector and the host layer.

[0081] According to one embodiment, the formation and / or growth of lithium dendrites on the negative electrode current collector can be effectively prevented. In addition, the cycle characteristics and stability of a lithium metal battery employing the negative electrode are improved.

[0082] The first lithium ion conductive polymer and the second lithium ion conductive polymer

[0083] Weight average molecular weight of 10,000 to 500,000 Dalton, 10,000 to 500,000 Dalton,

[0084] It may be 10,000 to 400,000 Dalton, 10,000 to 300,000 Dalton, 10,000 to 200,000 Dalton, 50,000 to 150,000 Dalton, 70,000 to 100,000 Dalton, or 80,000 to 100,000 Dalton. When the weight average molecular weights of the first lithium ion conductive polymer and the second lithium ion conductive polymer are within the above range, lithium deposition occurs within the host layer, and lithium metal can be bottom-up deposited within the host layer.

[0085] In the present disclosure, the weight average molecular weight can be measured by gel permeation chromatography.

[0086] According to an embodiment, the negative electrode may further include a negative electrode active material layer.

[0087] The above negative active material layer is a carbon-based material; a carbon-based material, and a first metal.

[0088] A composition comprising one or more selected mixtures; one or more composites selected from a carbonaceous material and a first metal; or a combination thereof, wherein the carbonaceous material comprises amorphous carbon, and the average particle size of the amorphous carbon is from 10 nm to 100 nm. The carbonaceous material comprises carbon black, carbon nanotubes, carbon nanofibers, fullerenes, activated carbon, carbon fibers, or a combination thereof.

[0089] A lithium metal layer may be further disposed between the negative electrode current collector and one surface of the protective layer.

[0090] There is. A lithium metal layer can be further disposed on the other surface opposite to the one surface of the above protective layer.

[0091] According to another aspect, the positive electrode; the negative electrode according to an embodiment; and the positive electrode and the negative electrode

[0092] A lithium metal battery including an electrolyte disposed therebetween is provided.

[0093] The above electrolyte is a liquid electrolyte, a solid electrolyte, a gel polymer electrolyte or a combination thereof.

[0094] The above solid electrolyte includes an oxide-based solid electrolyte, a sulfide-based solid electrolyte, a polymer solid electrolyte, or a combination thereof, and the above gel electrolyte contains a polymer gel electrolyte.

[0095] The positive electrode includes a positive electrode current collector and a positive electrode active material layer, and at least one of the positive electrode current collector and the negative electrode current collector includes a base film and a metal layer disposed on one or both sides of the base film, and the base film includes a polymer, and the polymer includes polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), polyimide (PI), or a combination thereof.

[0096] The above metal layer includes 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 an alloy thereof.

[0097] Referring to FIG. 3, a lithium metal battery (1) has a negative electrode (20) including a negative electrode current collector (21), and the negative electrode active material layer is absent.

[0098] A host structure (22) is formed between the negative electrode current collector (21) and the electrolyte (30). The host structure includes a host layer, a first MCMB-containing layer, and a second MCMB-containing layer, and the host layer is disposed adjacent to the negative electrode current collector.

[0099] Lithium metal may be included in the host layer, between the host layer and the first MCMB layer, the second MCMB layer, or a combination thereof.

[0100] A positive electrode (10) is sequentially arranged on top of the above electrolyte (30). The positive electrode (10) contains a positive electrode active material layer (12) and a positive electrode current collector (11).

[0101] A negative electrode active material layer may be further disposed between the negative electrode current collector (21) and the host structure (22). The negative electrode active material layer may include lithium metal or a lithium alloy.

[0102] The lithium metal may include, for example, a lithium metal foil, a lithium alloy foil, or a combination thereof. The lithium metal may be in the form of a lithium powder. The lithium powder may include, for example, a lithium metal powder, a lithium alloy powder, or a combination thereof. A lithium alloy is an alloy of lithium and another metal that can be alloyed with lithium, such as a lithium-silver alloy, a lithium-zinc alloy, a lithium-magnesium alloy, or a lithium-tin alloy. The negative electrode active material layer including a lithium metal foil may be, for example, a lithium metal layer. The negative electrode active material layer including a lithium alloy foil may be, for example, a lithium alloy layer. The negative electrode active material layer including a lithium metal powder and / or a lithium alloy powder may be introduced by coating a slurry including lithium powder and a binder onto a negative electrode current collector. The binder may be, for example, a fluorine-based binder such as polyvinylidene fluoride (PVDF). The negative electrode active material layer may not include a carbon-based negative electrode active material. Therefore, the negative electrode active material layer may be formed of a metal-based negative electrode active material.

[0103] The thickness of the lithium metal may be, for example, 1 μm to 50 μm, 1 μm to 30 μm, or 10 μm to 30 μm, or 10 μm to 80 μm. By having the lithium metal have a thickness in this range, the life characteristics of the lithium metal battery having the host structure can be further improved.

[0104] A lithium metal battery according to an embodiment does not include a negative electrode active material layer disposed between a negative electrode current collector (21) and a host structure (22). An anode not including a negative electrode active material layer may include a negative electrode active material layer by plating lithium metal between a negative electrode current collector (21) and a host structure (22) upon charging after being introduced into a lithium metal battery together with a positive electrode and an electrolyte. The negative electrode active material layer may be a lithium plating layer (plated lithium layer).

[0105] Lithium metal batteries may further include a separator.

[0106] The pore diameter of the separator is generally 0.01 to 10 μm, and the thickness can generally be 5 to 20 μm. Examples of such separators include sheets or non-woven fabrics made of olefin-based polymers such as polypropylene, glass fiber, or polyethylene. When a solid polymer electrolyte is used as the electrolyte, the solid polymer electrolyte may also function as the separator.

[0107] Among the above separation membranes, specific examples of olefin-based polymers include polyethylene, polypropylene, or a multilayer membrane of two or more layers thereof, and mixed multilayer membranes such as a polyethylene / polypropylene two-layer separation membrane, a polyethylene / polypropylene / polyethylene three-layer separation membrane, and a polypropylene / polyethylene / polypropylene three-layer separation membrane may be used.

[0108] The above separator may include a porous substrate and a coating layer including an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0109] The above porous substrate may be a polymer film formed of any one polymer selected from polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyacetal, polyamide, polyimide, polycarbonate, polyether ketone, polyarylether ketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene oxide, cyclic olefin copolymer, polyphenylene sulfide, polyethylene naphthalate, glass fiber, Teflon, and polytetrafluoroethylene, or a copolymer or mixture of two or more thereof.

[0110] The organic material may include a polyvinylidene fluoride polymer or a (meth)acrylic polymer.

[0111] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0112] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0113] In a lithium metal battery according to an embodiment, the liquid electrolyte contains a lithium salt and an organic solvent.

[0114] The organic solvent serves as a medium through which ions involved in the electrochemical reaction of the battery can move. The organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof.

[0115] Examples of the above carbonate solvents that can be used include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC).

[0116] Ester solvents that can be used include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanolide, mevalonolactone, valerolactone, and caprolactone.

[0117] Examples of ether solvents that can be used include dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, and tetrahydrofuran. In addition, examples of ketone solvents that can be used include cyclohexanone. Examples of alcohol solvents that can be used include ethyl alcohol and isopropyl alcohol, and examples of aprotic solvents that can be used include nitriles such as R-CN (where R is a linear, branched, or cyclic hydrocarbon group having 2 to 20 carbon atoms and may include a double bond, an aromatic ring, or an ether group); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane and 1,4-dioxolane; and sulfolanes.

[0118] The above non-aqueous organic solvents can be used alone or in combination of two or more.

[0119] In addition, when using a carbonate solvent, a cyclic carbonate and a chain carbonate can be mixed and used, and the cyclic carbonate and the chain carbonate can be mixed in a volume ratio of 1:1 to 1:9.

[0120] As the organic solvent, for example, an aprotic organic solvent such as N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyrolactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyl tetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxy methane, dioxolane derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ethers, methyl pyropionate, ethyl propionate, etc. can be used. Carbonate solvents such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, and diethyl carbonate can be used.

[0121] The above lithium salt is a substance that dissolves in an organic solvent and acts as a source of lithium ions in the battery, enabling the basic operation of a lithium secondary battery and promoting the movement of lithium ions between the positive and negative electrodes. Representative examples of lithium salts include LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N (lithium bis(fluorosulfonyl)imide (LiFSI), LiC4F9SO3, LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2) (x and y are integers from 1 to 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalato)phosphate (LiDFOB), lithium bis(oxalato)borate (LiBOB).

[0122] The concentration of the lithium salt is, for example, 0.1 M to 5.0 M, 0.1 to 3 M, or 0.5 to 2 M in the liquid electrolyte. In the above range, a sufficient amount of lithium ions required for charging and discharging a lithium metal battery can be generated.

[0123] When a gel-type polymer electrolyte exists in the pores of a porous substrate, the interfacial resistance between the positive electrode, negative electrode, and separator is minimized, and lithium movement becomes easier.

[0124] According to one embodiment, the negative electrode active material layer can be arranged during the assembly of the lithium metal battery. According to another embodiment, the negative electrode active material layer can include a negative electrode active material layer by plating lithium metal after charging. For example, the negative electrode active material layer can be omitted during battery assembly and formed by plating lithium metal after charging. According to another embodiment, the negative electrode active material layer can be a lithium plating layer (plated lithium layer).

[0125] The above negative electrode active material layer includes lithium metal or a lithium alloy.

[0126] When the negative electrode active material layer is placed at the time of assembly, it may include only a carbon-based material, a carbon-based material, and at least one selected from metals and metalloids.

[0127] The carbon-based material includes amorphous carbon, and the average particle diameter of the amorphous carbon is 10 nm to 100 nm, and the carbon-based material includes carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), graphene, or a combination thereof.

[0128] The above negative active material layer includes a lithium metal foil, a lithium metal powder, a lithium alloy foil, a lithium alloy powder, or a combination thereof, wherein the lithium alloy contains lithium and a first metal.

[0129] The first metal is indium (In), silicon (Si), gallium (Ga), tin (Sn), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), gold (Au), platinum (Pt), palladium (Pd), magnesium (Mg), silver (Ag), zinc (Zn), nickel, iron, cobalt, chromium, cesium, sodium, potassium, calcium, yttrium, bismuth, tantalum, hafnium, barium, vanadium, strontium, lanthanum, or a combination thereof.

[0130] The negative electrode active material layer may include, for example, a lithium metal foil, a lithium alloy foil, lithium powder, or a combination thereof. The negative electrode active material layer including the lithium metal powder and / or the lithium alloy powder may be introduced by coating a slurry including lithium powder and a binder on a negative electrode current collector. The binder may be, for example, a fluorine-based binder such as polyvinylidene fluoride (PVDF). The negative electrode active material layer may not include a carbon-based negative electrode active material. In one embodiment, the active material layer is substantially free of a carbon-based negative electrode active material, so that a carbon-based negative electrode active material may be present, or even if present, may exist only as a secondary impurity. In another embodiment, the active material layer may be completely free of a carbon-based negative electrode active material. Accordingly, the negative electrode active material layer may be formed of a metal-based negative electrode active material.

[0131] The above binder serves to adhere the negative electrode active material particles well to each other and also to adhere the negative electrode active material well to the current collector. The binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof.

[0132] Examples of the non-aqueous binder include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or combinations thereof.

[0133] The above-mentioned aqueous binder may be selected from styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomer, polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenol resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0134] When using an aqueous binder as the above-mentioned negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included. The cellulose-based compound may be a mixture of one or more of carboxymethyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, or an alkali metal salt thereof. The alkali metal may be Na, K, or Li.

[0135] As a conductive material for the negative electrode, it is used to provide conductivity to the electrode, and in the battery to be constructed, any material that does not cause chemical change and is electronically conductive can be used. Specific examples include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal-based materials in the form of metal powder or metal fiber, including copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0136] The above dry binder is a polymeric material capable of being fiberized, and may be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or a combination thereof.

[0137] The negative electrode current collector may include, for example, a base film and a metal layer disposed on one or both sides of the base film. 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 a combination thereof. The polymer may be an insulating polymer. Since the base film includes an insulating thermoplastic polymer, when a short circuit occurs, the base film may soften or liquefy, thereby blocking battery operation and suppressing a rapid increase in current. The metal layer may include, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), or an alloy thereof. The metal layer may correspond to, for example, the first metal substrate. The metal layer may additionally include a coating layer including a second metal. The negative electrode current collector (21) may additionally include a metal piece and / or a lead tab. For more specific details regarding the base film, metal layer, metal chip, and lead tab of the negative electrode current collector, refer to the positive electrode current collector described below. By having such a structure, the negative electrode current collector can reduce the weight of the negative electrode, thereby improving the energy density of the negative electrode and the lithium metal battery.

[0138] In the present disclosure, the positive electrode current collector (11) is a plate or foil made 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 an alloy thereof. The thickness of the positive electrode current collector is, for example, 1 µm to 100 µm, 1 µm to 50 µm, 5 µm to 25 µm, or 10 µm to 20 µm.

[0139] The cathode current collector may include, for example, a base film and a metal layer disposed on one or both sides of the base film. 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 a combination thereof. The base film may be, for example, an insulator. Since the base film includes an insulating thermoplastic polymer, when a short circuit occurs, the base film may soften or liquefy, thereby blocking battery operation and suppressing a sudden increase in current. The metal layer may include, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), or an alloy thereof. The metal layer can act as an electrochemical fuse and cut off in case of overcurrent to prevent short circuits. The limit current and maximum current can be controlled by adjusting the thickness of the metal layer. The metal layer can be plated or deposited on the base film. As the thickness of the metal layer decreases, the limit current and / or maximum current of the positive electrode current collector decreases, thereby improving the stability of the lithium metal battery in case of a short circuit. A lead tab can be added to the metal layer for external connection. The lead tab can be welded to the metal layer or the metal layer / base film laminate by ultrasonic welding, laser welding, spot welding, etc. During welding, the base film and / or the metal layer melt, so that the metal layer can be electrically connected to the lead tab. To strengthen the welding between the metal layer and the lead tab, a metal chip can be added between the metal layer and the lead tab.The metal piece may be a thin piece of the same material as the metal of the metal layer. The metal piece may be, for example, a metal foil, a metal mesh, etc. The metal piece may be, for example, aluminum foil, copper foil, SUS foil, etc. After the metal piece is placed on the metal layer, the lead tab may be welded to the metal piece / metal layer laminate or the metal piece / metal layer / base film laminate. During welding, the base film, the metal layer, and / or the metal piece may melt, so that the metal layer or the metal layer / metal piece laminate may be electrically connected to the lead tab. A metal chip and / or a lead tab may be added to a portion of the metal layer. The base film may have a thickness of, for example, 1 to 50 μm, 1.5 to 50 μm, 1.5 to 40 μm, or 1 to 30 μm. When the base film has a thickness in this range, the weight of the electrode assembly can be more effectively reduced. The melting point of the base film may be, for example, 100 to 300°C, 100 to 250°C or less, or 100 to 200°C. Since the base film has a melting point within this range, the base film can be melted and easily bonded to the lead tab during the welding process of the lead tab. To improve the adhesion between the base film and the metal layer, a surface treatment such as corona treatment may be performed on the base film. The thickness of the metal layer may be, for example, 0.01 to 3 μm, 0.1 to 3 μm, 0.1 to 2 μm, or 0.1 to μm. Since the metal layer has a thickness within this range, conductivity can be maintained while ensuring the stability of the electrode assembly. The thickness of the metal piece may be, for example, 2 to 10 μm, 2 to 7 μm, or 4 to 6 μm. Since the metal piece has a thickness within this range, the connection between the metal layer and the lead tab can be performed more easily. By having this structure as the cathode current collector, the weight of the cathode can be reduced, and as a result, the energy density of the cathode and lithium battery can be improved.

[0140] The negative electrode active material layer may contain a negative electrode active material and a binder.

[0141] The negative active material has, for example, a particle form. The average particle diameter of the negative active material having a particle form is, for example, 10 nm to 10 ㎛, 10 nm to 1 ㎛, 10 nm to 500 nm, 10 nm to 100 nm, or 20 nm to 80 nm. When the negative active material has an average particle diameter in this range, reversible plating and / or dissolution of lithium can be facilitated during charge and discharge. The average particle diameter of the negative active material is, for example, a median diameter (D50) measured using a laser particle size distribution analyzer.

[0142] The negative electrode active material may include, for example, at least one selected from a carbon-based negative electrode active material and a metal or metalloid negative electrode active material. The carbon-based negative electrode active material may be, for example, amorphous carbon. Examples of the carbon-based negative electrode active material include, but are not limited to, carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), graphene, etc., and any material classified as amorphous carbon in the relevant technical field may be used. Amorphous carbon is carbon that has no crystallinity or very low crystallinity, and is distinguished from crystalline carbon or graphite-based carbon. The metal or metalloid negative electrode active material includes, but is not limited to, one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn), and any metal or metalloid negative electrode active material that forms an alloy or compound with lithium in the relevant technical field may be used. For example, nickel (Ni) does not form an alloy with lithium, and therefore is not a metal negative electrode active material in the present specification. The negative electrode active material layer includes a type of negative electrode active material among these negative electrode active materials, or includes a mixture of a plurality of different negative electrode active materials. For example, the negative electrode active material layer may include a mixture of amorphous carbon and one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The mixing ratio of the mixture may be, for example, 10:1 to 1:2, 10:1 to 1:1, 7:1 to 1:1, 5:1 to 1:1, or 4:1 to 2:1 by weight.The negative electrode active material included in the negative electrode active material layer may include a mixture of first particles made of, for example, amorphous carbon and second particles made of a metal or a metalloid. The metal includes, for example, gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The content of the second particles is 8 to 60 wt%, 10 to 50 wt%, 15 to 40 wt%, or 20 to 30 wt% based on the total weight of the mixture. When the second particles have a content in this range, the cycle characteristics of, for example, a lithium metal battery are further improved.

[0143] The binder included in the negative electrode active material layer may be, for example, styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, etc., but is not necessarily limited thereto, and any binder used in the relevant technical field may be used. The binder may be composed of a single binder or a plurality of different binders. When the negative electrode active material layer does not include a binder, the negative electrode active material layer can be easily separated from the ceramic coating layer (21) or the negative electrode current collector (21). The content of the binder included in the negative electrode active material layer may be, for example, 1 to 20 wt% based on the total weight of the negative electrode active material layer.

[0144] The thickness of the negative electrode active material layer may be, for example, 0.1 ㎛ to 500 ㎛, or 100 ㎛ to 50 ㎛. The thickness of the negative electrode active material layer may be, for example, 1% to 50%, 1% to 30%, 1% to 10%, or 1% to 5% of the thickness of the positive electrode active material layer. If the thickness of the negative electrode active material layer is too thin, lithium dendrites formed between the negative electrode active material layer and the negative electrode current collector may collapse the negative electrode active material layer, making it difficult to improve the cycle characteristics of the lithium metal battery. If the thickness of the negative electrode active material layer increases excessively, the energy density of the lithium metal battery employing the negative electrode (20) may decrease, and it may be difficult to improve the cycle characteristics.

[0145] When the thickness of the negative electrode active material layer decreases, the charge capacity of the negative electrode active material layer also decreases, for example. The charge capacity of the negative electrode active material layer may be, for example, 0.1% to 50%, 1% to 30%, 1% to 10%, 1% to 5%, or 1% to 2% of the charge capacity of the positive electrode active material layer. If the charge capacity of the negative electrode active material layer is too small, lithium dendrites formed between the negative electrode active material layer and the negative electrode current collector may collapse the negative electrode active material layer, making it difficult to improve the cycle characteristics of the lithium metal battery. If the charge capacity of the negative electrode active material layer increases excessively, the energy density of the lithium metal battery using the negative electrode (20) may decrease, and it may be difficult to improve the cycle characteristics. The charge capacity of the positive electrode active material layer is obtained by multiplying the charge capacity density (mAh / g) of the positive electrode active material by the mass of the positive electrode active material in the positive electrode active material layer. When multiple types of positive electrode active materials are used, the charge capacity density × mass value is calculated for each positive electrode active material, and the sum of these values ​​is the charge capacity of the positive electrode active material layer. The charge capacity of the negative electrode active material layer is also calculated in the same way. That is, the charge capacity of the negative electrode active material layer is obtained by multiplying the charge capacity density (mAh / g) of the negative electrode active material by the mass of the negative electrode active material in the negative electrode active material layer. When multiple types of negative electrode active materials are used, the charge capacity density × mass value is calculated for each negative electrode active material, and the sum of these values ​​is the capacity of the negative electrode active material layer. Here, the charge capacity density of the positive electrode active material and the negative electrode active material is the estimated capacity using a half-cell using lithium metal as a counter electrode. The charge capacity of the positive electrode active material layer and the negative electrode active material layer are directly measured by measuring the charge capacity using the half-cell. The charge capacity density is obtained by dividing the measured charge capacity by the mass of each active material. Alternatively, the charge capacity of the positive electrode active material layer and the negative electrode active material layer may be the initial charge capacity measured at the first charge cycle.

[0146] [Lithium metal battery]

[0147] According to one embodiment, a lithium metal battery includes a positive electrode; a negative electrode; and an electrolyte disposed between the positive electrode and the negative electrode. The lithium metal battery may further include a separator. Such a lithium metal battery can simultaneously provide excellent life characteristics.

[0148] Lithium metal batteries may be, but are not limited to, lithium primary batteries, lithium secondary batteries, lithium-sulfur batteries, lithium-air batteries, etc., and any lithium metal battery used in the relevant technical field may be used.

[0149] Lithium metal batteries are manufactured by, for example, the following exemplary methods, but are not necessarily limited to these methods and are adjusted according to required conditions.

[0150] (anode)

[0151] First, a positive electrode active material composition is prepared by mixing a positive electrode active material, a conductive agent, a binder, and a solvent. The prepared positive electrode active material composition is directly coated on an aluminum current collector and dried to produce a positive electrode plate having a positive electrode active material layer formed thereon. Alternatively, the positive electrode active material composition is cast on a separate support, and then the film obtained by peeling from the support is laminated on the aluminum current collector to produce a positive electrode plate having a positive electrode active material layer formed thereon.

[0152] A compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) can be used as a cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0153] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0154] As an example, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Lia FePO4(0.90≤a≤1.8).

[0155] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1 is Mn, Al or a combination thereof.

[0156] For example, the cathode active material may be a high-nickel cathode active material in which the nickel content is 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less, based on 100 mol% of metals excluding lithium in the lithium transition metal composite oxide. The high-nickel cathode active material can realize high capacity and thus can be applied to high-capacity, high-density lithium secondary batteries.

[0157] It is also possible to use a compound having a coating layer added to the surface of the above-described positive electrode compound, or it is also possible to use a mixture of the above-described compound and a compound having a coating layer added. The coating layer added to the surface of the above-described compound includes, for example, a coating element compound of an oxide, a hydroxide, an oxyhydroxide of the coating element, an oxycarbonate of the coating element, or a hydroxycarbonate of the coating element of the coating element. The compound forming the coating layer is amorphous or crystalline. The coating elements included in the coating layer are Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The method for forming the coating layer is selected within a range that does not adversely affect the physical properties of the positive electrode active material. Examples of the coating method include spray coating and dipping. Since specific coating methods are well understood by those working in the relevant field, a detailed description thereof will be omitted.

[0158] The cathode active material is, for example, Li a Ni x Co y M z O 2-b A b (1.0≤a≤1.2, 0≤b≤0.2, 0.8≤x<1, 0 <y≤0.3, 0<z≤0.3, 및 x+y+z=1이고, M은 망간(Mn), 니오븀(Nb), 바나듐(V), 마그네슘(Mg), 갈륨(Ga), 실리콘(Si), 텅스텐(W), 몰리브덴(Mo), 철(Fe), 크롬(Cr), 구리(Cu), 아연(Zn), 티타늄(Ti), 알루미늄(Al), 보론(B) 또는 이들의 조합이고, A는 F, S, Cl, Br 또는 이들의 조합), LiNi x Co y Mn z O2(0.8≤x≤0.95, 0≤y≤0.2, 0 <z≤0.2 및 x+y+z=1), LiNi x Co y Al z O2(0.8≤x≤0.95, 0≤y≤0.2, 0 <z≤0.2 및 x+y+z=1), LiNi x Co y Mn z Al w O2(0.8≤x≤0.95, 0≤y≤0.2, 0 <z≤0.2, 0<w≤0.2, 및 x+y+z+w=1), Li a Co x M y O 2-b A b (1.0≤a≤1.2, 0≤b≤0.2, 0.9≤x≤1, 0≤y≤0.1, and 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 a combination thereof, and A is F, S, Cl, Br or a combination thereof), Li a Ni x Mn y M' z O2-b A b (1.0≤a≤1.2, 0≤b≤0.2, 0 <x≤0.3, 0.5≤y<1, 0<z≤0.3, 및 x+y+z=1이고, M'는 코발트(Co), 니오븀(Nb), 바나듐(V), 마그네슘(Mg), 갈륨(Ga), 실리콘(Si), 텅스텐(W), 몰리브덴(Mo), 철(Fe), 크롬(Cr), 구리(Cu), 아연(Zn), 티타늄(Ti), 알루미늄(Al), 보론(B) 또는 이들의 조합이고, A는 F, S, Cl, Br 또는 이들의 조합), Li a M1 x M2 y PO 4-b X b (Here, 0.90≤a≤1.1, 0≤x≤0.9, 0≤y≤0.5, 0.9 <x+y<1.1, 0≤b≤2 이며, M1이 크롬(Cr), 망간(Mn), 철(Fe), 코발트(Co), 니켈(Ni), 구리(Cu), 지르코늄(Zr) 또는 이들의 조합이며, M2가 마그네슘(Mg), 칼슘(Ca), 스트론튬(Sr), 바륨(Ba), 티탄(Ti), 아연(Zn), 보론(B), 니오븀(Nb), 갈륨(Ga), 인듐(In), 몰리브덴(Mo), 텅스텐(W), 알루미늄(Al), 실리콘(Si), 크롬(Cr), 바나듐(V), 스칸듐(Sc), 이트륨(Y) 또는 이들의 조합이며, X가 O, F, S, P 또는 이들의 조합), Li a M3 z PO4 (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 a combination thereof).

[0159] The conductive material is used to provide conductivity to the electrode, and any material that does not cause chemical changes and is electronically conductive can be used in the battery. Examples of the conductive material include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal-based materials containing copper, nickel, aluminum, silver, etc. in the form of metal powder or metal fiber; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0160] Alternatively, the anode may not include a separate conductor, for example.

[0161] The binder helps the positive electrode active material particles adhere well to each other and also helps the positive electrode active material adhere well to the current collector. Representative examples of binders include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, nylon, etc.

[0162] It is also possible to form pores inside the electrode plate by further adding a plasticizer or a pore forming agent to the positive electrode active material composition.

[0163] The positive electrode may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or a conductive material.

[0164] For example, the anode may further include an additive that can act as a sacrificial anode.

[0165] The contents of the cathode active material, conductive agent, binder, and solvent used in the cathode are at levels typically used in lithium batteries. Depending on the intended use and configuration of the lithium metal battery, one or more of the conductive agent, binder, and solvent may be omitted.

[0166] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0167] The positive electrode current collector is, for example, a plate or foil made of 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 an alloy thereof. The positive electrode current collector may be omitted. The thickness of the positive electrode current collector is, for example, 1 ㎛ to 100 ㎛, 1 ㎛ to 50 ㎛, 5 ㎛ to 25 ㎛, or 10 ㎛ to 20 ㎛.

[0168] The cathode current collector may include, for example, a base film and a metal layer disposed on one or both sides of the base film. The base film may include, for example, a polymer. The polymer may include, for example, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), polyimide (PI), or a combination thereof. The metal layer may include, 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 an alloy thereof. By having such a structure, the cathode current collector can reduce the weight of the electrode and consequently improve the energy density of a lithium metal battery.

[0169] (electrolyte)

[0170] Next, an electrolyte is prepared. The electrolyte can be, for example, a liquid electrolyte, a solid electrolyte, a gel electrolyte, or a combination thereof. The electrolyte is, for example, an organic electrolyte. An organic electrolyte is prepared by dissolving a lithium salt in an organic solvent.

[0171] Any organic solvent used in the relevant technical field may be used. Examples of the organic solvent include propylene carbonate, ethylene carbonate, fluoroethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl isopropyl carbonate, dipropyl carbonate, dibutyl carbonate, benzonitrile, 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 mixtures thereof.

[0172] Lithium salts are all possible if they are used as lithium salts in the relevant technical field. Lithium salts include, for example, LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, Li(CF3SO2)2N, LiC4F9SO3, LiAlO2, LiAlCl4, LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2)(1≤x≤20, 1≤y≤20), LiCl, LiI or a mixture thereof. The concentration of the lithium salt is, for example, 0.1 M to 5.0 M.

[0173] The solid electrolyte is, for example, an oxide-based solid electrolyte, a sulfide-based solid electrolyte, a polymer solid electrolyte, or a combination thereof.

[0174] Solid electrolytes are, for example, oxide-based solid electrolytes. Oxide-based solid electrolytes are Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 <x<2, 0≤y<3), BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT)(O≤x<1, O≤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(0 <x<2, 0<y<3), Li x Al y Ti z (PO4)3(0 <x<2, 0<y<1, 0<z<3), Li 1+x+y (Al, Ga) x (Ti, Ge) 2-x Si y P 3-yO 12 (0≤x≤1 0≤y≤1), Li x La y TiO3(0 <x<2, 0<y<3), Li2O, LiOH, Li2CO3, LiAlO2, Li2O-Al2O3-SiO2-P2O5-TiO2-GeO2, Li 3+x La3M2O 12 (M = Te, Nb, or Zr, x is an integer from 1 to 10) is one or more selected from. The solid electrolyte is manufactured by a sintering method, etc. For example, the oxide-based solid electrolyte is Li7La3Zr2O 12 (LLZO) and Li 3+x La3Zr 2-a M a O 12 A garnet-type solid electrolyte selected from (M doped LLZO, M=Ga, W, Nb, Ta, or Al, x is an integer from 1 to 10).

[0175] The sulfide-based solid electrolyte may include, for example, lithium sulfide, silicon sulfide, phosphorus sulfide, boron sulfide, or a combination thereof. The sulfide-based solid electrolyte particles may include Li2S, P2S5, SiS2, GeS2, B2S3, or a combination thereof. The sulfide-based solid electrolyte particles may be Li2S or P2S5. Sulfide-based solid electrolyte particles are known to have high lithium ion conductivity compared to other inorganic compounds. For example, the sulfide-based solid electrolyte includes Li2S and P2S5. When the sulfide solid electrolyte material constituting the sulfide-based solid electrolyte includes Li2S-P2S5, the mixing molar ratio of Li2S to P2S5 may be, for example, in a range of about 50:50 to about 90:10. In addition, Li3PO4, halogen, halogen compound, Li 2+2x Zn 1-x GeO4("LISICON", 0≤x<1), Li 3+y PO 4-x N x( "LIPON", 0 <x<4, 0<y<3), Li3.25 Ge 0.25 P 0.75 S4("Thio-LISICON"), Li2O-Al2O3-TiO2-P2O 5( An inorganic solid electrolyte prepared by adding "LATP") etc. to an inorganic solid electrolyte of Li2S-P2S5, SiS2, GeS2, B2S3, or a combination thereof can be used as a sulfide solid electrolyte. Non-limiting examples of sulfide solid electrolyte materials include Li2S-P2S5; Li2S-P2S5-LiX (X=halogen element); 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 (0 <m<10, 0<n<10, Z=Ge, Zn 또는 Ga); Li2S-GeS2; Li2S-SiS2-Li3PO4; 및 Li2S-SiS2-Li p MO q (0 <p<10, 0<q<10, M=P, Si, Ge, B, Al, Ga 또는 In)을 포함한다. 이와 관련하여, 황화물계 고체전해질 재료는 황화물계 고체전해질 물질의 원료 시작 물질(예를 들면, Li2S, P2S5, 등)을 용융 담금질법(melt quenching method), 기계적 밀링법 등에 의해 처리함으로써 제조될 수 있다. 또한, 소성(calcinations) 공정이 상기 처리 후에 수행될 수 있다. 황화물계 고체전해질은 비정질이거나, 결정질이거나, 이들이 혼합된 상태일 수 있다.

[0176] The polymer solid electrolyte may, for example, comprise a mixture of a lithium salt and a polymer, or a polymer having an ion-conducting functional group. The polymer solid electrolyte may, for example, be a polymer electrolyte that is solid at 25°C and 1 atm. The polymer solid electrolyte may, for example, not comprise a liquid.The polymer solid electrolyte comprises a polymer, and the polymer is, for example, polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyethylene oxide (PEO), poly(styrene-b-ethylene oxide) block copolymer (PS-PEO), poly(styrene-butadiene), poly(styrene-isoprene-styrene), poly(styrene-b-divinylbenzene) block copolymer, poly(styrene-ethylene oxide-styrene) block copolymer, polystyrene sulfonate (PSS), polyvinyl fluoride (PVF), polymethyl methacrylate (PMMA, poly(methylmethacrylate), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), polyethylenedioxythiophene (PEDOT), polypyrrole (PPY), Polyacrylonitrile (PAN), polyaniline, polyacetylene, Nafion, Aquivion, Flemion, Gore, Aciplex, Morgane ADP, sulfonated poly(ether ether ketone) (SPEEK), sulfonated poly(arylene ether ketone ketone sulfone) (SPAEKKS), sulfonated poly(aryl ether ketone) (SPAEK), poly[bis(benzimidazobenzisoquinolinones)] (SPBIBI), poly(styrene sulfonate) (PSS), lithium 9,10-Diphenylanthracene-2-sulfonate (lithium 9,10-diphenylanthracene-2-sulfonate, DPASLi. +) or a combination thereof, but is not limited thereto, and any lithium salt that can be used in polymer electrolytes in the relevant technical field is possible. The lithium salt can be any lithium salt that can be used in the relevant technical field. The lithium salt is, for example, LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, Li(CF3SO2)2N, LiC4F9SO3, LiAlO2, LiAlCl4, LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2) (x and y are each 1 to 20), LiCl, LiI or a mixture thereof, etc. The polymer included in the polymer solid electrolyte may be, for example, a compound including 10 or more, 20 or more, 50 or more or 100 or more repeating units. The weight average molecular weight of the polymer included in the polymer solid electrolyte may be, for example, 1000 Dalton or more, 10,000 Dalton or more, 100,000 Dalton or more or 1,000,000 Dalton or more.

[0177] A gel electrolyte is, for example, a polymer gel electrolyte. A gel electrolyte can have a gel state without containing a polymer, for example.

[0178] A polymer gel electrolyte may include, for example, a liquid electrolyte and a polymer, or an organic solvent and a polymer having an ion-conducting functional group. The polymer gel electrolyte may be, for example, a polymer electrolyte that is in a gel state at 25°C and 1 atm. The polymer gel electrolyte may, for example, have a gel state without containing a liquid. The liquid electrolyte used in the polymer gel electrolyte may be, for example, an ionic liquid, a mixture of a lithium salt and an organic solvent; a mixture of a lithium salt and an organic solvent; a mixture of an ionic liquid and an organic solvent; or a mixture of a lithium salt, an ionic liquid, and an organic solvent. The polymer used in the polymer gel electrolyte may be selected from among the polymers used in solid polymer electrolytes. The organic solvent may be selected from among the organic solvents used in liquid electrolytes. The lithium salt may be selected from among the lithium salts used in solid polymer electrolytes. An ionic liquid refers to a salt that has a melting point below room temperature, is composed solely of ions, and is liquid at room temperature or a molten salt at room temperature. The ionic liquid may include, for example, one or more cations selected from among a) ammonium compounds, pyrrolidinium compounds, pyridinium compounds, pyrimidinium compounds, imidazolium compounds, piperidinium compounds, pyrazolium compounds, oxazolium compounds, pyridazinium compounds, phosphonium compounds, sulfonium compounds, triazolium compounds, and mixtures thereof, and b) one or more anions selected from among BF4-, PF6-, AsF6-, SbF6-, AlCl4-, HSO4-, ClO4-, CH3SO3-, CF3CO2-, Cl-, Br-, I-, BF4-, SO4-, CF3SO3-, (FSO2)2N-, (C2F5SO2)2N-, (C2F5SO2)(CF3SO2)N-, and (CF3SO2)2N-. A polymer solid electrolyte can form a polymer gel electrolyte, for example, by being impregnated into a liquid electrolyte in a secondary battery. The polymer gel electrolyte may further include inorganic particles.The polymer included in the polymer gel electrolyte may be, for example, a compound containing 10 or more, 20 or more, 50 or more, or 100 or more repeating units. The weight average molecular weight of the polymer included in the polymer gel electrolyte may be, for example, 500 Dalton or more, 1000 Dalton or more, 10,000 Dalton or more, 100,000 Dalton or more, or 1,000,000 Dalton or more.

[0179] A separator may be further placed between the anode and cathode.

[0180] Any separator commonly used in lithium batteries can be used. For example, a separator with low resistance to ion transport and excellent electrolyte absorption capacity is used. The separator may be selected from glass fiber, polyester, Teflon, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), or combinations thereof, and may be in nonwoven or woven form. For lithium-ion batteries, rollable separators, such as polyethylene or polypropylene, are used, while for lithium-ion polymer batteries, separators with excellent organic electrolyte absorption capacity are used.

[0181] The membrane is manufactured by the following exemplary method, but is not limited to this method and may be adjusted according to required conditions.

[0182] First, a separator composition is prepared by mixing a polymer resin, a filler, and a solvent. The separator composition is directly coated and dried on the electrode to form a separator. Alternatively, the separator composition is cast onto a support and dried, and then a separator film peeled from the support is laminated onto the electrode to form a separator.

[0183] The polymer used in membrane manufacturing is not limited; any polymer used in the electrode plate binder can be used. Examples include vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, or mixtures thereof.

[0184] (cathode)

[0185] The cathode contains a cathode current collector.

[0186] In one embodiment of the present invention, the negative electrode current collector may include, for example, a base film and a metal layer disposed on one or both sides of the base film. 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 a combination thereof. Since the base film includes a thermoplastic polymer, the base film can be liquefied when a short circuit occurs, thereby suppressing a sudden increase in current. The base film may be, for example, an insulator. The metal layer may include, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), or an alloy thereof. The metal layer may act as an electrochemical fuse, which may be cut in the event of an overcurrent to prevent a short circuit. The limit current and maximum current can be controlled by adjusting the thickness of the metal layer. The metal layer may be plated or deposited on the base film. As the thickness of the metal layer decreases, the limit current and / or maximum current of the negative electrode current collector (521b, 522b) decrease, thereby improving the stability of the lithium metal battery in the event of a short circuit. A lead tab may be added on the metal layer for external connection. The lead tab may be welded to the metal layer or the metal layer / base film laminate by ultrasonic welding, laser welding, spot welding, etc. During welding, the base film and / or the metal layer may be melted, so that the metal layer may be electrically connected to the lead tab. In order to strengthen the welding of the metal layer and the lead tab, a metal piece may be added between the metal layer and the lead tab. The metal piece may be a thin piece of the same material as the metal of the metal layer.The metal piece may be, for example, a metal foil, a metal mesh, etc. The metal piece may be, for example, an aluminum foil, a copper foil, a SUS foil, etc. After the metal piece is placed on the metal layer, the lead tab may be welded to the metal piece / metal layer laminate or the metal piece / metal layer / base film laminate by welding the lead tab. During welding, the base film, the metal layer, and / or the metal piece may melt, so that the metal layer or the metal layer / metal piece laminate may be electrically connected to the lead tab. A metal chip and / or a lead tab may be added to a portion of the metal layer. The base film may have a thickness of, for example, 1 to 50 ㎛, 1.5 to 50 ㎛, 1.5 to 40 ㎛, or 1 to 30 ㎛. When the base film has a thickness in this range, the weight of the electrode assembly can be more effectively reduced. The melting point of the base film may be, for example, 100 to 300°C, 100 to 250°C, or 100 to 200°C. Since the base film has a melting point within this range, the base film can be melted and easily bonded to the lead tab during the process of welding the lead tab. To improve the adhesion between the base film and the metal layer, a surface treatment such as corona treatment may be performed on the base film. The thickness of the metal layer may be, for example, 0.01 to 3 μm, 0.1 to 3 μm, 0.1 to 2 μm, or 0.1 to ㎛. Since the metal layer has a thickness within this range, the stability of the electrode assembly can be secured while maintaining conductivity. The thickness of the metal piece may be, for example, 2 to 10 μm, 2 to 7 μm, or 4 to 6 μm. Since the metal piece has a thickness within this range, the connection between the metal layer and the lead tab can be performed more easily. By having this structure as the negative electrode collector, the weight of the electrode can be reduced, and as a result, the energy density of the lithium metal battery can be improved.

[0187] A negative electrode active material layer may be formed on the negative electrode current collector. The negative electrode active material layer may be formed as a lithium deposition layer after charging. Alternatively, the negative electrode active material layer may be formed using a negative electrode active material during battery assembly.

[0188] The method of forming a negative electrode active material layer using a negative electrode active material can be manufactured in the same manner as described above, except that the negative electrode active material is used instead of the positive electrode active material when forming the positive electrode active material layer.

[0189] A lithium metal battery may further include, for example, a thin film comprising an element capable of forming an alloy with lithium on one surface of an anode current collector. The thin film is disposed between the anode current collector and the anode active material layer. The thin film includes, for example, an element capable of forming an alloy with lithium. The element capable of forming an alloy with lithium includes, but is not limited to, gold, silver, zinc, tin, indium, silicon, aluminum, bismuth, etc., and any element capable of forming an alloy with lithium in the art may be used. The thin film may be composed of one of these metals or an alloy of several types of metals. By disposing the thin film on one surface of the anode current collector, for example, the deposition shape of the first anode active material layer deposited between the thin film and the anode active material layer becomes flatter, and the cycle characteristics of the lithium metal battery may be further improved.

[0190] (Separator)

[0191] A separator commonly used in lithium metal batteries can be used. The separator may contain a liquid electrolyte, which is manufactured, for example, by dissolving a lithium salt in an organic solvent.

[0192] The concentration of the lithium salt is, for example, 0.1 M to 5.0 M, 0.1 to 3 M, or 0.5 to 2 M.

[0193] A lithium metal battery according to one embodiment may further include a solid electrolyte. The solid electrolyte is, for example, an oxide-based solid electrolyte, a sulfide-based solid electrolyte, or a combination thereof.

[0194] Solid electrolytes are, for example, oxide-based solid electrolytes. Oxide-based solid electrolytes are Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 <x<2, 0≤y<3), Li3PO4, Li x Ti y (PO4)3(0 <x<2, 0<y<3), Li x Al y Ti z (PO4)3(0 <x<2, 0<y<1, 0<z<3), Li 1+x+y (Al, Ga) x (Ti, Ge) 2-x Si y P 3-y O 12 (0≤x≤1 0≤y≤1), Li x La y TiO3(0 <x<2, 0<y<3), Li2O, LiOH, Li2CO3, LiAlO2, Li2O-Al2O3-SiO2-P2O5-TiO2-GeO2, Li 3+x La3M2O 12 (M = Te, Nb, or Zr, x is an integer from 1 to 10) is one or more selected from. The solid electrolyte is manufactured by a sintering method, etc. For example, the oxide-based solid electrolyte is Li7La3Zr2O 12 (LLZO) and Li 3+x La3Zr 2-a M a O 12 A garnet-type solid electrolyte selected from (M doped LLZO, M=Ga, W, Nb, Ta, or Al, x is an integer from 1 to 10).

[0195] The sulfide-based solid electrolyte may include, for example, lithium sulfide, silicon sulfide, phosphorus sulfide, boron sulfide, or a combination thereof. The sulfide-based solid electrolyte particles may include Li2S, P2S5, SiS2, GeS2, B2S3, or a combination thereof. The sulfide-based solid electrolyte particles may be Li2S or P2S5. Sulfide-based solid electrolyte particles are known to have high lithium ion conductivity compared to other inorganic compounds. For example, the sulfide-based solid electrolyte includes Li2S and P2S5. When the sulfide solid electrolyte material constituting the sulfide-based solid electrolyte includes Li2S-P2S5, the mixing molar ratio of Li2S to P2S5 may be, for example, in a range of about 50:50 to about 90:10. In addition, Li3PO4, halogen, halogen compound, Li 2+2x Zn 1??x GeO4("LISICON", 0≤x<1), Li 3+y PO 4-x N x( "LIPON", 0 <x<4, 0<y<3), Li 3.25 Ge 0.25 P 0.75 S4("ThioLISICON"), Li2O-Al2O3-TiO2-P2O 5( An inorganic solid electrolyte prepared by adding "LATP") etc. to an inorganic solid electrolyte of Li2S-P2S5, SiS2, GeS2, B2S3, or a combination thereof can be used as a sulfide solid electrolyte. Non-limiting examples of sulfide solid electrolyte materials include Li2S-P2S5; Li2S-P2S5-LiX (X=halogen element); 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(0 <m<10, 0<n<10, Z=Ge, Zn 또는 Ga); Li2S-GeS2; Li2S-SiS2-Li3PO4; 및 Li2S-SiS2-Li p MO q (0 <p<10, 0<q<10, M=P, Si, Ge, B, Al, Ga 또는 In)을 포함한다. 이와 관련하여, 황화물계 고체전해질 재료는 황화물계 고체전해질 물질의 원료 시작 물질(예를 들면, Li2S, P2S5, 등)을 용융 담금질법(melt quenching method), 기계적 밀링법 등에 의해 처리함으로써 제조될 수 있다. 또한, 소성(calcinations) 공정이 상기 처리 후에 수행될 수 있다. 황화물계 고체전해질은 비정질이거나, 결정질이거나, 이들이 혼합된 상태일 수 있다.

[0196] (lithium metal battery)

[0197] Referring to FIG. 5, a lithium metal battery (1) according to one embodiment includes a positive electrode (3), a negative electrode (2) according to one embodiment, and an electrolyte (4). A gel-type polymer electrolyte (not shown) may be placed between the electrolyte and the positive electrode. The positive electrode (3), the negative electrode (2), and the electrolyte (4) are wound or folded, and the battery structure (7) is accommodated in a battery case (5). An organic electrolyte is injected into the battery case (5) and sealed with a cap assembly, thereby completing the lithium metal battery (1). The battery case (5) is not limited to a cylindrical shape, but may be, for example, a square shape, a thin film shape, etc.

[0198] Referring to FIG. 5, a lithium metal battery (1) according to one embodiment includes a positive electrode (3), a negative electrode (2), and an electrolyte (4). An electrolyte (4) is disposed between the positive electrode (3) and the negative electrode (2), and the positive electrode (3), the negative electrode (2), and the separator (4) are wound or folded to form a battery structure (7). The formed battery structure (7) is accommodated in a battery case (5). An electrode tab (8) that serves as an electrical path for guiding the current formed in the battery structure (7) to the outside may be included. An organic electrolyte is injected into the battery case (5) and sealed to complete the lithium metal battery (1). The battery case (5) is not limited to a square shape or such a shape, and may be, for example, a cylindrical shape, a thin film shape, etc.

[0199] Referring to FIG. 6, a lithium metal battery (1) according to one embodiment includes a positive electrode (3), a negative electrode (2) according to one embodiment, and an electrolyte (4). An electrolyte (4) is disposed between the positive electrode (3) and the negative electrode (2), thereby forming a battery structure. A gel-type polymer electrolyte between the separator and the positive electrode is not shown. A battery structure (7) is stacked in a bi-cell structure and then accommodated in a battery case (5). An electrode tab (8) that serves as an electrical path for guiding the current formed in the battery structure (7) to the outside may be included. An organic electrolyte is injected into the battery case (5) and sealed, thereby completing the lithium metal battery (1). The battery case (5) is not necessarily limited to a square shape, and may be, for example, a cylindrical shape, a thin-film shape, etc.

[0200] A pouch-type lithium metal battery corresponds to the lithium metal batteries of FIGS. 5 and 6, each of which uses a pouch as a battery case. The pouch-type lithium metal battery includes one or more battery structures. An electrolyte is disposed between a positive electrode and a negative electrode, or an electrolyte and a separator are disposed to form a battery structure. The battery structures are laminated in a bi-cell structure, then impregnated with a liquid electrolyte, and accommodated and sealed in a pouch, thereby completing a pouch-type lithium metal battery. For example, although not shown in the drawings, the above-described positive electrode, negative electrode, and separator may be simply laminated and accommodated in a pouch in the form of an electrode assembly, or may be wound or folded into a jellyroll-shaped electrode assembly and then accommodated in a pouch. Subsequently, an organic electrolyte is injected into the pouch and sealed, thereby completing a lithium metal battery.

[0201] The lithium metal battery of the present disclosure has excellent discharge capacity and cycle life characteristics, as well as high energy density, and is therefore used in, for example, electric vehicles (EVs). For example, it is used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). It is also used in applications requiring large amounts of power storage, such as electric bicycles and power tools.

[0202] Lithium metal batteries are stacked in multiple layers to form a battery module, and the multiple battery modules form a battery pack. Such a battery pack can be used in any device requiring high capacity and high output. For example, it can be used in laptops, smartphones, electric vehicles, etc. The battery module includes, for example, multiple batteries and a frame that holds them. The battery pack includes, for example, multiple battery modules and a bus bar that connects them. The battery module and / or the battery pack may further include a cooling device. The multiple battery packs are controlled by a battery management system. The battery management system includes a battery pack and a battery control device connected to the battery pack.

[0203] [Method for manufacturing lithium metal batteries]

[0204] A lithium metal battery according to an embodiment includes a step of preparing a negative electrode current collector; a step of forming a host structure on the negative electrode current collector; a step of preparing an electrolyte; a step of preparing a positive electrode; and a step of preparing an assembly by laminating a negative electrode current collector, a host structure, an electrolyte, and a positive electrode.

[0205] The step of forming a host structure on the negative electrode current collector includes the steps of forming a host layer on the negative electrode current collector; the step of electrospinning a composition containing MCMB and a first lithium ion conductive polymer; and the step of electrospraying a composition containing MCMB and a second lithium ion conductive polymer, followed by drying.

[0206] The above first lithium ion conductive polymer and the second lithium ion conductive polymer

[0207] Electrical conductivity is 10 -8 S / m or less, and the content of the second lithium ion conductive polymer is greatly controlled compared to the content of the first lithium ion conductive polymer.

[0208] The above electrospraying is electrospinning or electrospraying.

[0209] Electrospraying is also well known in the art. Electrospraying is a method of applying a high voltage to a solution to impart an electric charge, and then spraying the charged solution onto a substrate through a fine-diameter spray nozzle or a spray head that generates droplets. Electrospraying includes electrospinning or electrospraying. Korean Patent Publication No. 2009-0054385 discloses a method of electrospinning using an electrospraying device comprising a syringe (syringe pump), a syringe needle, a bottom electrode (a stainless steel drum capable of controlling the rotation speed), and a spinning voltage supply device, wherein the distance between the tip of the syringe needle and the drum is 5 to 30 cm, the spinning voltage is 15 kV or higher, and the flow rate of the spinning solution from the syringe pump is 1 to 20 ml / hr. In addition, Korean Patent Registration No. 0271116 describes in detail an electrospraying device and method. The above documents are also incorporated as references to the present invention.

[0210] An electrode coated with a host layer composition on a current collector is positioned on a substrate of an electrospray device, and the first MCMB layer composition or the second MCMB layer composition prepared on the outer surface is electrosprayed, thereby forming the first MCMB layer and the second MCMB layer, respectively. At this time, the porosity of the coating layer can be optimized by adjusting the spacing between injection needles, the conveying speed of the substrate, etc. according to a known method.

[0211] The step of forming a host layer on the above negative electrode collector can be performed, for example, using a casting method.

[0212] The above lithium metal battery may further include a separator. The separator may further include a liquid electrolyte and / or a gel-type polymer electrolyte.

[0213] The present invention is explained in more detail through the following examples and comparative examples. However, the examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0214] (Manufacturing of cathodes and lithium metal batteries)

[0215] Example 1: Negative current collector / host layer (MCMB layer) / first MCMB-containing layer (PAN+MCMB at a weight ratio of 1:12 / second MCMB-containing layer (PAN+MCMB at a weight ratio of 1:7)

[0216] The active material MCMB (mesophase spheroidal graphite particles) and the binders SBR and CMC were mixed in a weight ratio of 95:3:2. The binder was prepared as a 1 wt% binder aqueous solution. The active material and the 1 wt% binder aqueous solution were mixed using a vortex mixer, and then uniformly dispersed using a sink mixer to prepare a slurry composition for forming an MCMB layer. The MCMB had a size of 16 μm and a specific surface area of ​​2 m. 2 / g, and the true density is 2.19g / cm 2 am.

[0217] The composition for forming the MCMB layer was coated on top of a copper foil having a thickness of 18 μm, which is the negative current collector, and dried in a vacuum oven at 25°C for one day to form a structure in which the negative current collector and the MCMB layer (thickness: 30 μm), which is the host layer, were arranged.

[0218] A composition having a weight ratio of MCMB:PAN of 12:1 and a composition having a weight ratio of 7:1 were sequentially electrospun on the upper part of the above structure to form a first MCMB-containing layer containing MCMB and PAN at a weight ratio of 12:1 and a second MCMB-containing layer containing MCMB and PAN at a weight ratio of 7:1.

[0219] The first electrospinning composition for forming the first MCMB-containing layer was prepared by dissolving PAN in DMF, stirring the mixture at 40°C for 12 hours, and then adding MCMB to the mixture so that the weight ratio of MCMB and PAN was 12:1.

[0220] Then, sonication was performed for 1 hour using a sonicator to prepare the composition, and DMF was added to adjust the viscosity so that the composition could be electrospun, and the composition was stirred for 1 hour at room temperature (25°C). Here, the viscosity of the composition is about 1,000 cp, and the total content of DMF in the first electrospinning composition is 70 parts by weight based on 100 parts by weight of the total weight of MCMB and PAN, and 40 parts by weight based on 100 parts by weight of the total weight of DMF, MCMB, and PAN.

[0221] A second electrospinning composition for forming a second MCMB-containing layer was prepared in the same manner as the first electrospinning composition, except that MCMB and PAN were used in a weight ratio of 7:1.

[0222] The above first electrospun composition was transferred as a solution through a tube with an inner diameter of 0.5 mm at a flow rate of 0.4 ml / hr using a syringe pump, and then electrospun onto an MCMB layer by applying 19 kV and drying at 25°C for 12 hours to form a first MCMB-containing layer.

[0223] Next, the second electrospun composition was transferred as a solution through a tube with an inner diameter of 0.5 mm at a flow rate of 0.4 ml / hr using a syringe pump, and then electrospun on the first MCMB-containing layer by applying 19 kV and drying at 25°C for 12 hours to form a second MCMB-containing layer.

[0224] The thickness of the first MCMB-containing layer obtained through the above process is 30 um, and the thickness of the second MCMB-containing layer is 30 um.

[0225] The cathode obtained through the above process was dried at room temperature (25°C) for about a day to manufacture the cathode.

[0226] As a separator, a polyethylene single film with a thickness of 20㎛ is laminated and the other separator

[0227] A laminate was manufactured by laminating lithium metal on one side. A liquid electrolyte was injected into the prepared laminate to manufacture a half-cell type coin cell.

[0228] As a liquid electrolyte, 1 M LiFSI was added to a mixed solvent of bis(2,2,2-trifluoroethyl)ether (BTFE) / dimethoxyethane (DME) at a weight ratio of 7:1.

[0229] Example 2: Negative current collector / MCMB layer / first MCMB-containing layer (PAN+MCMB at a weight ratio of 1:10 / second MCMB-containing layer (PAN+MCMB at a weight ratio of 1:5)

[0230] A lithium metal battery having a host layer, a first MCMB-containing layer, and a second MCMB-containing layer was manufactured in the same manner as in Example 1, except that the composition of each composition was changed so that the first MCMB-containing layer contained PAN and MCMB in a weight ratio of 1:10 and the second MCMB-containing layer contained PAN and MCMB in a weight ratio of 1:5.

[0231] Example 3: Negative current collector / host layer (MCMB layer) / first MCMB-containing layer (PEO+MCMB at a weight ratio of 1:12 / second MCMB-containing layer (PEO+MCMB at a weight ratio of 1:7)

[0232] A lithium metal battery having a host layer, a first MCMB-containing layer, and a second MCMB-containing layer was manufactured in the same manner as in Example 1, except that polyethylene oxide (PEO) was used instead of PAN.

[0233] Example 4

[0234] A lithium metal battery having a host layer, a first MCMB-containing layer, and a second MCMB-containing layer was manufactured in the same manner as in Example 1, except that the thickness of the host layer was changed to 30 um, the thickness of the first MCMB-containing layer was changed to 20 um, and the thickness of the second MCMB-containing layer was changed to 10 um.

[0235] Example 5: Negative current collector / MCMB layer / First MCMB-containing layer (PAN+MCMB at a weight ratio of 1:11) / Second MCMB-containing layer (PAN+MCMB at a weight ratio of 1:6)

[0236] A lithium metal battery having a host layer, a first MCMB-containing layer, and a second MCMB-containing layer was manufactured in the same manner as in Example 1, except that the composition of each composition was changed so that the first MCMB-containing layer contained PAN and MCMB in a weight ratio of 1:11 and the second MCMB-containing layer contained PAN and MCMB in a weight ratio of 1:6.

[0237] Comparative Example 1

[0238] A negative electrode and a lithium metal battery were manufactured in the same manner as in Example 1, except that the first MCMB-containing layer and the second MCMB-containing layer were not formed.

[0239] Comparative Example 2

[0240] An anode and a lithium metal battery having the same were manufactured in the same manner as in Example 1, except that reduced graphene oxide (RGO), a plate-shaped carbon-based material, was used instead of MCMB when forming the MCMB layer, the first MCMB-containing layer, and the second MCMB layer.

[0241] Comparative Example 3

[0242] A negative electrode and a lithium metal battery were manufactured in the same manner as in Example 1, except that Al2O3 was used instead of MCMB when forming the first MCMB-containing layer and the second MCMB layer.

[0243] Comparative Example 4

[0244] An anode and a lithium metal battery were manufactured in the same manner as in Example 1, except that the mixing weight ratio of MCMB and PAN was 7:1 when forming the first MCMB-containing layer, and that the mixing weight ratio of MCMB and PAN was 12:1 when forming the second MCMB layer.

[0245] According to Comparative Example 4, unlike in Examples 1 to 5, the PAN content of the first MCMB-containing layer was significantly controlled compared to the PAN content of the second MCMB-containing layer.

[0246] Evaluation Example 1: Scanning Electron Microscope (SEM)

[0247] The charge-discharge characteristics of the lithium metal batteries of Example 1 and Comparative Example 1 were evaluated under the following conditions. The lithium deposition pattern after charging was confirmed on the negative electrode of each lithium metal battery.

[0248] The battery was charged at a constant current of 0.1 C rate at 25°C until the voltage reached 4.3 V (vs. Li), and then cut-off at a current of 0.05 C rate while maintaining 4.3 V in constant voltage mode. Subsequently, the battery was discharged at a constant current of 0.1 C rate until the voltage reached 3.6 V (vs. Li) (formation cycle).

[0249] The lithium metal battery, which had undergone a Mars cycle, was charged at a constant current of 0.2 C rate at 25°C until the voltage reached 4.3 V (vs. Li), and then cut-off at a current of 0.05 C rate while maintaining 4.3 V in constant voltage mode. Subsequently, the battery was discharged at a constant current of 0.5 C rate until the voltage reached 3.6 V (vs. Li) (1 st cycle). These cycles are 9 th The cycle was repeated under the same conditions.

[0250] The lithium deposition pattern after charging was confirmed and the SEM images are shown in Figs. 1a and 1b. Fig. 1a is for the lithium metal battery of Example 1 and Fig. 1b is for the lithium metal battery of Comparative Example 1. Unlike the case of Example 1, Fig. 1b is for the battery after 5 cycles.

[0251] As shown in FIGS. 1a and 1b, it was confirmed that lithium was densely deposited inside the lithium host layer in the lithium metal battery of Example 1, even though it performed more charge / discharge cycles than Comparative Example 1, and the degree of lithium deposition on the upper part of the second MCMB-containing layer was greatly reduced.

[0252] In comparison, it was confirmed that the lithium metal battery of Comparative Example 1 had a lithium electrodeposition layer formed on top of the MCMB layer.

[0253] Evaluation Example 2: Charge / Discharge Characteristics

[0254] The voltage change according to the areal capacity of the lithium metal batteries of Example 1 and Comparative Example 1 was investigated under the following conditions. The lithium intercalation:plating ratio was adjusted to be maintained at 1:1.

[0255] The battery was charged at a constant current of 0.1 C rate at 25°C until the voltage reached 10 mV (vs. Li), then cut-off at a current of 0.01 C rate while maintaining 10 mV in constant voltage mode. Subsequently, the battery was discharged at a constant current of 0.1 C rate until the voltage reached 1 V (vs. Li) (formation cycle).

[0256] The lithium metal battery that had undergone the Mars cycle was charged at a constant current of 0.5 C rate for 2 hours at 25°C, and then discharged at a constant current of 0.5 C rate until the voltage reached 1 V (vs. Li) (1 st The evaluation results are shown in Figure 2.

[0257] Referring to Fig. 2, it was found that the lithium metal battery of Comparative Example 1 had a smaller decrease in intercalation capacity than that of Example 1.

[0258] Evaluation Example 3: Coolong Efficiency

[0259] The charge-discharge characteristics of the lithium metal batteries of Example 1-5 and Comparative Example 1-2 were evaluated under the following conditions. The lithium intercalation:plating ratio was adjusted to be maintained at 1:1.

[0260] The battery was charged at a constant current of 0.1 C rate at 25°C until the voltage reached 10 mV (vs. Li), then cut-off at a current of 0.01 C rate while maintaining 10 mV in constant voltage mode. Subsequently, the battery was discharged at a constant current of 0.1 C rate until the voltage reached 1 V (vs. Li) (formation cycle).

[0261] The lithium metal battery that had undergone the Mars cycle was charged at a constant current of 0.5 C rate for 2 hours at 25°C, and then discharged at a constant current of 0.5 C rate until the voltage reached 1 V (vs. Li) (1 st cycle). These cycles are 65 th The cycle was repeated under the same conditions.

[0262] In all charge / discharge cycles, a 10-minute pause was allowed after each charge / discharge cycle. Some of the results of the room temperature charge / discharge experiments are shown in Table 1 below. The Coulomb efficiency in each cycle is defined by Equation 1 below, and the capacity retention rate is defined by Equation 2 below. When the discharge capacity is maintained at 80% or more of the single discharge capacity after 65 cycles, it is marked with ○, and when the discharge capacity is less than 80%, it is marked with X.

[0263] <Formula 1>

[0264] Coolong efficiency [%] = [10 cycle discharge capacity / 10 cycle charge capacity] × 100

[0265] <Formula 2>

[0266] Capacity retention rate (%) = (65 discharge capacity / 1 discharge capacity) X 100

[0267] Classification Cooling efficiency (%) Capacity retention rate Example 199.43 ○ Example 299.38 ○ Example 399.35 ○ Example 499.40 ○ Example 599.28 ○ Comparative example 197.20 X Comparative example 296.87 X Comparative example 396.23 X Comparative example 495.53 X

[0268] As shown in Table 1, the lithium metal batteries of Examples 1 to 5 showed improved Coulomb efficiency compared to the lithium metal batteries of Comparative Examples 1 to 4, and it was found that the capacity retention characteristics were improved compared to the lithium metal batteries of Comparative Examples 1 to 4.

[0269] The lithium metal battery of Comparative Example 2 used reduced graphene oxide (RGO), a plate-like carbon material, instead of MCMB when forming the MCMB layer, the first MCMB-containing layer, and the second MCMB layer of the negative electrode, resulting in a higher reactivity and poorer resistance characteristics compared to MCMB, resulting in lower Coulomb efficiency and capacity retention rate compared to the lithium metal batteries of Examples 1 to 5, as shown in Table 1.

[0270] Referring to Table 1, the lithium metal battery of Comparative Example 3, which has a negative electrode using Al2O3 instead of MCMB when forming the first MCMB-containing layer and the second MCMB layer, exhibited lower Coulomb efficiency and capacity retention characteristics than the lithium metal batteries of Examples 1 to 5. In addition, the lithium metal battery of Comparative Example 4, which has a negative electrode in which the content of PAN in the second MCMB layer is higher than the PAN content in the first MCMB layer when forming the first MCMB-containing layer and the second MCMB layer, exhibited lower Coulomb efficiency and capacity retention characteristics than the lithium metal battery of Example 1.

[0271] Evaluation Example 4: Porosity

[0272] The porosity of the negative electrode, host layer, first MCMB-containing layer, and second MCMB-containing layer in the lithium metal battery manufactured according to Example 1 was analyzed using a scanning electron microscope, and is shown in Table 2 below. The volume occupied by the pores was investigated using a scanning electron microscope and determined as the porosity.

[0273] Example 1 Cathode 60 Host layer 55 1 MCMB containing layer 58 2 MCMB containing layer 68

[0274] From Table 2, the porosity increased in the order of the host layer, the first MCMB-containing layer, and the second MCMB-containing layer manufactured according to Example 1.

[0275] While exemplary embodiments have been described in detail with reference to the attached drawings, the present invention is not limited to these examples. It is self-evident that those skilled in the art to which the present invention pertains can devise various modifications or variations within the scope of the technical concepts described in the patent claims, and these also naturally fall within the technical scope of the present invention.

Claims

1. Negative current collector; A host layer containing mesocarbon microbeads (MCMB) positioned on the negative electrode current collector; A first MCMB-containing layer containing MCMB and a first lithium ion conductive polymer, Containing a second MCMB-containing layer containing MCMB and a second lithium ion conductive polymer, The first lithium ion conductive polymer and the second lithium ion conductive polymer have an electrical conductivity of 10 -8 A negative electrode for a lithium metal battery, wherein the content of the second lithium ion conductive polymer is greater than that of the first lithium ion conductive polymer, and the content of the second lithium ion conductive polymer is less than S / m.

2. In paragraph 1, The above first lithium ion conductive polymer and the second lithium ion conductive polymer are negative electrodes for lithium metal batteries, each having a lithium-substitutable functional group.

3. In paragraph 1, The first lithium ion conductive polymer and the second lithium ion conductive polymer are each polyethylene oxide, polyacrylonitrile, polymethyl methacrylate, vinylidene fluoride-hexafluoropropylene copolymer, or a combination thereof, as a negative electrode for a lithium metal battery.

4. In paragraph 1, A negative electrode for a lithium metal battery, wherein the content of the first lithium ion conductive polymer is 3 to 20 parts by weight based on 100 parts by weight of the total weight of the first MCMB-containing layer.

5. In paragraph 1, A negative electrode for a lithium metal battery, wherein the content of the second lithium ion conductive polymer is 5 to 30 parts by weight based on 100 parts by weight of the total weight of the second MCMB-containing layer.

6. In paragraph 1, The thickness ratio of the host layer and the first MCMB containing layer is 5:1 to 1:1, A negative electrode for a lithium metal battery, wherein the thickness ratio of the host layer and the second MCMB-containing layer is 5:1 to 1:

1.

7. In paragraph 1, A negative electrode for a lithium metal battery, wherein the thickness of the host layer is 10 to 70 um.

8. In paragraph 1, The size of the above MCMB is 1 um to 50 um, and the specific surface area is 0.2 to 5 m 2 / g, and the true density is 2.10 g / cm 3 Ideal, negative electrode for lithium metal battery.

9. In paragraph 1, The thickness of the above first MCMB containing layer is 5 to 30 um, A negative electrode for a lithium metal battery, wherein the thickness of the second MCMB containing layer is 5 to 30 um.

10. In paragraph 1, A negative electrode for a lithium metal battery, wherein lithium metal is included in the host layer, between the host layer and the first MCMB-containing layer, the second MCMB-containing layer, or a combination thereof.

11. In paragraph 1, A negative electrode for a lithium metal battery, wherein the host layer further comprises a binder.

12. In paragraph 1, A negative electrode for a lithium metal battery, wherein the content of MCMB in the host layer is 85 to 97 parts by weight based on 100 parts by weight of the total weight of the host layer.

13. In paragraph 1, A negative electrode for a lithium metal battery, wherein the porosity of the negative electrode is 50 to 70%, the porosity of the host layer is 50 to 60%, the porosity of the first MCMB-containing layer is 55 to 65%, and the porosity of the second MCMB-containing layer is 65 to 75%.

14. In paragraph 1, The first lithium ion conductive polymer and the second lithium ion conductive polymer A negative electrode for a lithium metal battery, each having an average diameter of 0.001 nm to 1000 nm.

15. Bipolar; A cathode according to any one of the above clauses 1 to 14; and A lithium metal battery comprising an electrolyte disposed between the positive electrode and the negative electrode.

16. In paragraph 15, The above electrolyte is a liquid electrolyte, a solid electrolyte, a gel electrolyte or a combination thereof. Includes, The above solid electrolyte includes an oxide-based solid electrolyte, a sulfide-based solid electrolyte, a polymer solid electrolyte, or a combination thereof, A lithium metal battery, wherein the gel electrolyte comprises a polymer gel electrolyte.

17. In paragraph 15, The above lithium metal battery is a lithium metal battery further comprising a separator.

18. In paragraph 15, The above positive electrode includes a positive electrode current collector and a positive electrode active material layer, At least one of the positive electrode current collector and the negative electrode current collector includes a base film and a metal layer disposed on one or both sides of the base film, The above base film comprises a polymer, and the polymer comprises polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), polyimide (PI) or a combination thereof, A lithium metal battery, wherein the metal layer comprises 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 an alloy thereof.

19. Step of preparing the negative electrode collector; A step of forming a host layer on a negative electrode collector; A step of electrospraying a composition containing MCMB and a first lithium ion conductive polymer; A step of electrospraying a composition containing MCMB and a second lithium ion conductive polymer, and then drying the composition, The above first lithium ion conductive polymer and the second lithium ion conductive polymer Electrical conductivity is 10 -8 S / m or less, A method for manufacturing a negative electrode for a lithium metal battery, wherein the content of the second lithium ion conductive polymer is adjusted to be greater than the content of the first lithium ion conductive polymer, thereby manufacturing the negative electrode of claim 1.

20. A method for manufacturing a negative electrode for a lithium metal battery, wherein the electrospraying in paragraph 19 is electrospinning or electrospraying.

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