KR20210050059A - Lithium metal anode structure, electrochemical device including the same, and manufacturing method of the lithium metal anode structure - Google Patents

Abstract

Disclosed are a lithium metal negative electrode structure, an electrochemical device including the same, and a manufacturing method of the lithium metal negative electrode structure. The lithium metal negative electrode structure includes: a lithium metal negative electrode; and a separator attached to at least one surface of the lithium metal negative electrode, in which the separator includes a porous substrate and an inorganic layer including inorganic nanoparticles having a size of 5 to 200 nm coated on the porous substrate and the inorganic layer is positioned between the lithium metal negative electrode and the porous substrate. The lithium metal negative electrode structure is manufactured using a rolling roll or press, and accordingly, the surface of the lithium metal negative electrode is formed uniformly, and the sealing of the inorganic layer and the lithium metal negative electrode is improved, so that a lithium dendrite growth is inhibited and a reaction of lithium during the life cycle is minimized.

Description

A lithium metal anode structure, an electrochemical device including the same, and a method of manufacturing the lithium metal anode structure.

It relates to a lithium metal anode structure, an electrochemical device including the same, and a method of manufacturing the lithium metal anode structure.

According to the trend of light, thin, short and portable electric and electronic products, secondary batteries, which are core components, are also required to be lighter and smaller, and development of batteries having high output and high energy density is required. In response to these demands, one of the high-performance, next-generation, high-tech new batteries that are receiving the most attention in recent years is a lithium metal secondary battery.

Lithium metal anodes are currently attracting attention as a core material for next-generation batteries. As it has a specific capacity of 10 times or more compared to the negative electrode used in commonly used lithium-ion secondary batteries, the weight and thickness of the negative electrode can be drastically reduced, so it is usually used for battery development with an energy density of 400Wh/kg or 1000Wh/L or more. .

The method of manufacturing a lithium metal negative electrode is largely extruded and rolled to produce a lithium foil having a certain thickness, or the produced lithium foil is compressed and attached to a copper foil. Alternatively, lithium is deposited on another substrate using CVD or thermal evaporation to form a thin film.

Currently, the commonly used lithium anode is a rolled foil type lithium foil. In the process of extrusion, rolling, and compression, lithium is exposed to oil and impurities for fairness, or by excessive rolling to reduce the thickness of the lithium foil. Inconsistent patterns and damage. This leads to non-uniform surface reaction of the lithium negative electrode, leading to non-uniform growth of the lithium dendrite during battery charging/discharging, increasing the possibility of deteriorating the lifespan and causing a safety accident due to an internal short circuit.

In order to suppress the growth of lithium dendrites, inorganic or polymer coatings or solid electrolytes are sometimes used, but it is difficult to develop a process due to the reactivity and physical properties of lithium metal itself to directly coat the lithium metal anode. Is a situation where there is no coating method actually applied. In the case of evaporation, the size of the sample and the application of the continuous roll process are difficult, so it is limited to small R&D. In the case of a solid electrolyte, it is difficult to apply it to an actual mass-produced battery due to a problem of interface resistance with electrodes and a limitation of sample size.

One aspect of the present invention is to provide a lithium metal negative electrode structure capable of suppressing the growth of a lithium resin phase (Dendrite) and minimizing the reaction of lithium during a life cycle by forming a lithium metal negative electrode having a uniform surface.

Another aspect of the present invention is to provide an electrochemical device including the lithium metal anode structure.

Another aspect of the present invention is to provide a method of manufacturing the lithium metal negative electrode structure.

In one aspect of the present invention,

Lithium metal negative electrode; And

As a separator attached to at least one surface of the lithium metal negative electrode, the separator comprises a porous substrate and an inorganic layer including inorganic nanoparticles having a size of 5 to 200 nm coated on the porous substrate, and the inorganic layer is the lithium A separator positioned between the metal anode and the porous substrate;

A lithium metal anode structure comprising a is provided.

In another aspect of the present invention, an electrochemical device including the lithium metal anode structure is provided.

In another aspect of the present invention,

Including the step of binding the separator to at least one side of the lithium metal negative electrode using a rolling roll or press,

The separator includes a porous substrate and an inorganic layer including inorganic nanoparticles having a size of 5 to 200 nm coated on the porous substrate, and wherein the inorganic layer is positioned between the lithium metal negative electrode and the porous substrate. A method of manufacturing a metal cathode structure is provided.

In the lithium metal negative electrode structure according to an exemplary embodiment, the lithium metal negative electrode has a uniform surface, and the sealing of the inorganic layer and the lithium metal negative electrode is improved, thereby suppressing the growth of lithium dendrites and minimizing the reaction of lithium during the life cycle. Through this, the lithium metal anode structure may be applied to various electrochemical devices including lithium metal secondary batteries to improve life and stability.

1 is an exemplary schematic diagram of a lithium metal anode structure according to an embodiment.
2 is a diagram illustrating a battery stacking structure using a lithium metal anode structure according to an embodiment.
3 is an exemplary illustration showing a method of manufacturing a lithium metal negative electrode structure using a rolling roll.
4A is a photograph of a lithium metal negative electrode of Comparative Example 1,
4B is a photograph of a lithium metal anode structure of Example 1,
4C is a photograph showing a lithium metal anode with improved surface uniformity in the lithium metal anode structure of Example 1. FIG.
5 shows a photograph of the surface of a lithium metal negative electrode of Comparative Example 1 and a result of surface roughness analysis using a Keyence microscope.
6 shows a photograph of a surface of a lithium metal negative electrode in the lithium metal negative electrode structure of Example 1 and a result of analyzing the surface roughness using a Keyence microscope.
7 is a graph showing the results of measuring the discharge capacity for each cycle of the lithium metal batteries of Comparative Example 2 and Example 2.
8 is a graph showing the results of measuring the discharge capacity/charge capacity efficiency for each cycle of the lithium metal batteries of Comparative Example 2 and Example 2. FIG.
9 is an exemplary schematic diagram of a lithium metal battery according to an embodiment.

The present inventive concept described below can apply various transformations and have various embodiments. Specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the present creative idea to a specific embodiment, and it should be understood to include all transformations, equivalents, or substitutes included in the technical scope of the present creative idea.

The terms used below are only used to describe specific embodiments, and are not intended to limit the present inventive idea. Singular expressions include plural expressions unless the context clearly indicates otherwise. Hereinafter, terms such as "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts, components, materials, or a combination thereof described in the specification. It is to be understood that the above other features, or the possibility of the presence or addition of numbers, steps, actions, components, parts, components, materials, or combinations thereof, are not excluded in advance. "/" used below may be interpreted as "and" or "or" depending on the situation.

In the drawings, the diameter, length, and thickness are enlarged or reduced in order to clearly express various elements, layers, and regions. Like reference numerals are attached to similar parts throughout the specification. Throughout the specification, when a part such as a layer, film, region, or plate is said to be "on" or "on" another part, this includes not only the case directly above the other part, but also the case where there is another part in the middle. . Throughout the specification, terms such as first and second may be used to describe various constituent elements, but constituent elements should not be limited by terms. The terms are used only to distinguish one component from another. In the drawings, some of the components may be omitted, but this is to aid understanding of the features of the invention and is not intended to exclude the omitted components.

Hereinafter, an exemplary lithium metal anode structure, an electrochemical device including the same, and a method of manufacturing the lithium metal anode structure will be described in more detail with reference to the accompanying drawings.

Lithium metal negative electrode structure according to one embodiment,

Lithium metal negative electrode; And

As a separator attached to at least one surface of the lithium metal negative electrode, the separator comprises a porous substrate and an inorganic layer including inorganic nanoparticles having a size of 5 to 200 nm coated on the porous substrate, and the inorganic layer is the lithium It includes; a separator positioned between the metal negative electrode and the porous substrate.

The lithium metal negative electrode structure is in a state in which the lithium metal negative electrode and the separator coated with the inorganic layer are integrated and rolled as a whole obtained through a rolling process. Accordingly, unlike the conventional lithium metal negative electrode having a non-uniform surface, the lithium metal negative electrode in the lithium metal negative electrode structure has a uniform surface with a surface roughness (Ra) of 1 or less. In the case of a lithium metal negative electrode through general roll rolling, which is currently commercially available, it is difficult to obtain a uniform surface due to the difference in elongation between the base foil (copper) and the lithium foil.

The lithium metal negative electrode structure not only has a uniform surface of the lithium metal negative electrode, but also improves the sealing of the inorganic layer and the lithium metal negative electrode, suppressing the growth of lithium dendrites on the surface of the lithium metal negative electrode, and minimizing the reaction of lithium during the life cycle. Therefore, it can be applied to various electrochemical devices including lithium metal secondary batteries to improve life and stability.

1 is an exemplary schematic diagram of a lithium metal anode structure according to an embodiment.

As shown in FIG. 1, the lithium metal anode structure 10 includes a separator 12 including a porous substrate 12a coated with an inorganic layer 12b on at least one side of the lithium metal anode 11, for example, both sides. ) Can have a bonded structure.

The lithium metal negative electrode 11 may be formed by rolling a lithium thin film 11a on both sides of a current collector 11b such as a copper foil through roll rolling or the like.

According to an embodiment, the surface roughness (Ra) of the surface of the lithium metal negative electrode 11 may be 1 or less, for example 0.9 or less, for example 0.8 or less, for example 0.7 or less, for example 0.6 or less, For example, it may be 0.5 or less, for example 0.4 or less, for example 0.3 or less, for example 0.2 or less, or for example 0.1 or less. By having the surface roughness within the above range, the lithium metal negative electrode has a uniform surface, and it is possible to suppress uneven growth of lithium dendrite on the surface during battery charging/discharging, thereby reducing lifespan and safety accidents due to internal short circuit. Can be suppressed.

The thickness of the lithium metal negative electrode may be 100 μm or less, for example, 80 μm or less, or 50 μm or less, or 30 μm or less, or 20 μm or less. According to another embodiment, the thickness of the lithium metal negative electrode may be 0.1 to 60㎛. Specifically, the thickness of the lithium metal negative electrode may be 1 to 25 μm, for example, 5 to 20 μm.

The separator includes a porous substrate and an inorganic layer including inorganic nanoparticles having a size of 5 to 200 nm coated on the porous substrate.

In the separator, the porous substrate may be a porous membrane containing polyolefin. The polyolefin has an excellent short-circuit prevention effect and can improve battery stability by a shutdown effect. For example, the porous substrate is at least one copolymer selected from polyethylene, polypropylene, polybutylene, polypentene, polyhexene, polyoctene, ethylene, propylene, butene, pentene, 4-methylpentene, hexene and octene, It may be a membrane made of a resin such as a mixture or a combination thereof, but is not necessarily limited thereto, and any porous membrane that can be used in the art may be used. For example, a porous membrane made of a polyolefin resin; A porous membrane in which polyolefin-based fibers are woven; Nonwoven fabric containing polyolefin; An aggregate of insulating material particles, etc. may be used. For example, a porous membrane containing polyolefin has excellent applicability of a binder solution for preparing a coating layer formed on the substrate, and can increase the capacity per unit volume by increasing the ratio of active materials in the battery by making the membrane thickness of the separator thin. .

The thickness of the porous substrate may be 1 μm to 50 μm. For example, the thickness of the porous substrate may be 1 μm to 30 μm. For example, the thickness of the porous substrate may be 3 μm to 20 μm. For example, the thickness of the porous substrate may be 3 μm to 15 μm. For example, the thickness of the porous substrate may be 3 μm to 12 μm. If the thickness of the porous substrate is less than 1 μm, it may be difficult to maintain the mechanical properties of the separator, and if the thickness of the porous substrate exceeds 50 μm, the internal resistance of the lithium battery may increase and the energy density of the lithium metal battery may be lost. .

The inorganic layer includes inorganic nanoparticles having a size of 5 to 200 nm.

According to an embodiment, the inorganic nanoparticles may include a ceramic material. The ceramic material is, for example, alumina (Al ₂ O ₃ ), silica (SiO ₂ ), zinc oxide, zirconium oxide (ZrO ₂ ), zeolite, titanium oxide (TiO ₂ ), barium titanate (BaTiO ₃ ), strontium titanate (SrTiO _3), calcium titanate (CaTiO _3), aluminum borate, iron oxide, calcium carbonate, barium carbonate, lead oxide, tin oxide, cerium, calcium oxide, sasanhwasam manganese, magnesium oxide, niobium oxide, tantalum oxide, oxide Tungsten, antimony oxide, aluminum phosphate, calcium silicate, zirconium silicate, ITO (tin-containing indium oxide), titanium silicate, montmorillonite, saponite, vermiculite, hydrotalcite, kaolinite, carnemite, margadiite, and kenyito It may include at least one selected from, but is not limited thereto.

According to another embodiment, the inorganic nanoparticles may include a solid electrolyte material. The solid electrolyte material may include at least one inorganic lithium ion conductor selected from oxide-based, phosphate-based, sulfide-based, and LiPON-based inorganic materials having lithium ion conductivity.

The inorganic lithium ion conductor is, for example, a garnet type compound, an azirodite type compound, a lithium super-ion-conductor (LISICON) compound, a Na super ionic conductor-like (NASICON) compound, a lithium nitride (Li nitride), lithium hydride, perovskite, lithium halide, and sulfide compounds.

The inorganic lithium ion conductor is, for example, Garnet-based ceramics Li _3+x La ₃ M ₂ O ₁₂ (0≦x≦5, M = W, Ta, Te, at least one of Nb and Zr), doped the garnet (garnet) ceramics _{Li 7-3x M 'x La 3 M} 2 O 12 (0 <x≤1, MW, Ta, Te, Nb, and wherein at least one of Zr, M' = Al, Ga , Nb , Ta, Fe, Zn, Y, Sm, and at least one of Gd), Li _1+x+y Al _x Ti _2-x Si _y P _3-y O ₁₂ (0<x<2, 0≤y<3) , BaTiO ₃ , Pb(Zr,Ti)O ₃ (PZT), Pb _1-x La _x Zr _1-y Ti _y O ₃ (PLZT)(O≤x<1, O≤y<1),Pb(Mg _1/3 Nb _2/3 )O ₃ -PbTiO ₃ (PMN-PT), lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ ,0<x<2,0<y<3), lithium aluminum titanium phosphate (Li _x Al _y Ti _z (PO ₄ ) 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 (O≤x≤1, O≤y≤1), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0<x<2) , 0<y<3), lithium germanium thiophosphate (LixGeyPzSw, 0<x<4, 0<y<1, 0<z<1, 0<w<5), lithium nitride (Li _x N _y , 0 <x<4, 0<y<2), SiS ₂ (Li _x Si _y S _z , 0≤<3,0<y<2, 0<z<4) series glass, P ₂ S ₅ (Li _x P _y S _z , 0≤x<3, 0<y<3, 0<z<7) series glass, Li _3x La _2/3-x TiO ₃ (0≤x≤1/6), Li ₇ La ₃ Zr ₂ O ₁₂ , Li _1+y Al _y Ti _2-y (PO ₄ ) ₃ (0≤y≤1) and Li _1+z Al _z Ge _2-z (PO ₄ ) ₃ (0≤z≤1), Li ₂ O, LiF, LiOH, Li ₂ CO ₃ , LiAlO ₂ , Li ₂ O-Al ₂ O ₃ -SiO ₂ -P ₂ O ₅ -TiO ₂ -GeO ₂ -based ceramics, Li ₁₀ GeP ₂ S ₁₂ , Li _3.25 Ge _0.25 P _0.75 S ₄ , Li ₃ PS ₄ , Li ₆ PS ₅ Br, Li ₆ PS ₅ Cl, Li ₇ PS ₅ , Li ₆ PS ₅ I, Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ , LiTi ₂ (PO ₄ ) ₃ , LiGe ₂ ( PO ₄ ) ₃ , LiHf ₂ (PO ₄ ) ₃ , LiZr ₂ (PO ₄ ) ₃ , Li ₂ NH ₂ , Li ₃ (NH ₂ ) ₂ I, LiBH ₄ , LiAlH ₄ , LiNH ₂ , Li _0.34 La _0.51 TiO _2.94 , LiSr ₂ Ti ₂ NbO ₉ , Li _0.06 La _0.66 Ti _0.93 Al _0.03 O ₃ , Li _0.34 Nd _0.55 TiO ₃ , Li ₂ CdCl ₄ , Li ₂ MgCl ₄ , Li ₂ ZnI ₄ , Li ₂ CdI ₄ , Li _4.9 Ga _{0.5 +δ} La ₃ Zr _1.7 W _0.3 O ₁₂ (0≤δ<1.6), Li _4.9 Ga _0.5+δ La ₃ Zr _1.7 W _0.3 O ₁₂ (1.7≤δ≤2.5), Li _5.39 Ga _0.5+δ La ₃ Zr _1.7 W _0.3 O ₁₂ (0≤δ≤1.11), Lithium Phosphorus Sulfide (LPS), Li ₃ PS ₄ ), Lithium Tin Sulfide (LTS), Li ₄ SnS ₄ ), Lithium Phosphorus Sulfur chloride iodide (Lithium Phosphorus Sulfur Chloride Iodide (LPSCLL), Li ₆ PS ₅ Cl _0.9 I _0.1 ), Lithium Tin Phosphorus Sulfide (LSPS), Li ₁₀ SnP ₂ S ₁₂ ), Li ₂ S, Li ₂ SP ₂ S ₅ , Li ₂ S-SiS ₂ , Li ₂ S-GeS ₂ , Li ₂ SB ₂ S ₅ , and Li ₂ S-Al ₂ S ₅ Including one or more selected from the group consisting of can do.

For example, as the inorganic lithium ion conductor, a garnet type LLZO, Al doped Lithium Lanthanum Zirconium Oxide (Li _7-3x Al _x La ₃ Zr ₂ O ₁₂ ) (0<x≤1), a pseudo oxide type solid electrolyte Lithium Lanthanum Titanate(LLTO) (Li _0.34 La _0.51 TiOy) (0<y≤3), Lithium Aluminum Titanium Phosphate(LATP) (Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ ) can be used as a sulfur compound. Lithium Phosphorus Sulfide(LPS) (Li ₃ PS ₄ ), Lithium Tin Sulfide(LTS) (Li ₄ SnS ₄ ) and Lithium Phosphorus Sulfur Chloride Iodide(LPSCLL) (Li ₆ PS ₅ Cl _0.9 I _0.1 ), Lithium Tin Phosphorus Sulfide (LSPS) (Li ₁₀ SnP ₂ S ₁₂ ) can be used.

The inorganic nanoparticles may have a particle or columnar strucuture, or other atypical shape.

The size of the inorganic nanoparticles may be 5 to 200 nm, for example 10 to 150 nm, for example 20 to 100 nm, for example 10 to 100 nm. The average particle diameter of the inorganic nanoparticles may improve the uniformity of the surface of the lithium metal negative electrode through the rolling process in the above range. In the present specification, "the size of the inorganic nanoparticles" indicates the average diameter when the inorganic nanoparticles are spherical and the long axis length when the inorganic nanoparticles are non-spherical. The size of the inorganic nanoparticles can be measured using a particle size measuring device or an electron scanning microscope.

The content of the inorganic nanoparticles is at least 10% by weight or more, 15% by weight or more, 20% by weight or more, 30% by weight or more, 40% by weight or more, 50% by weight, or 90% by weight or more based on the total weight of the coating layer. I can. For example, the content of the inorganic nanoparticles may range from 70 to 98% by weight based on the total weight of the coating layer. In the above range, it is possible to improve the surface uniformity of the lithium metal negative electrode and the sealing of the inorganic layer and the lithium metal negative electrode surface.

The inorganic layer may further include an organic binder. In this case, the inorganic layer may have a form in which inorganic nanoparticles are dispersed in a matrix made of an organic binder.

The organic binder is, for example, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene chloride, polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, polyurethane, poly Vinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethylmethacrylate, Polyaniline, acrylonitrile butadiene styrene, phenol resin, epoxy resin, polyethylene terephthalate, polytetrafluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, polyethylenesulfone, polyamide, polyacetal, polyethylene oxide, polyethylene glycol Selected from diacrylate, polyethylene glycol monoacrylate, polyphenylene oxide, polybutylene terephthalate, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, and copolymers thereof It may include at least one that is.

When the inorganic layer includes inorganic nanoparticles and organic binder, the content of the organic binder may be in the range of 50 to 99% by weight based on the total weight of the inorganic nanoparticles and the organic binder, for example, 60 to 98% by weight, Alternatively, it may be 70 to 97% by weight, or 80 to 96% by weight. When the content of the organic binder is within the above range, binding between the inorganic layer and the lithium metal negative electrode may be further improved.

According to an embodiment, the thickness of the inorganic layer may be 0.1 to 50 μm, for example, 1 to 5 μm, for example, 2 to 4 μm. In the above range, it is possible to improve the sealing between the inorganic layer and the lithium metal negative electrode while making the surface of the lithium metal negative electrode a uniform surface during the rolling process of the lithium metal negative electrode and the separator.

According to an embodiment, the separator may further include a polymer coating layer on the inorganic layer. The polymer coating layer may further improve the binding between the inorganic layer and the lithium metal negative electrode, and further suppress the growth of lithium dendrites.

Materials used for the polymer coating layer are, for example, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene chloride, polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, Polyurethane, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, recycled cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethyl Methacrylate, polyaniline, acrylonitrile butadiene styrene, phenol resin, epoxy resin, polyethylene terephthalate, polytetrafluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, polyethylenesulfone, polyamide, polyacetal, polyethylene Oxide, polyethylene glycol diacrylate, polyethylene glycol monoacrylate, polyphenylene oxide, polybutylene terephthalate, ethylene-propylene-diene terephthalate (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, and these It may be at least one selected from copolymers.

According to an embodiment, the polymer coating layer may include the same material as the organic binder used for the inorganic layer.

The thickness of the separator may be 14 to 20 μm and air permeability may be 180 to 300 sec/100cc, and may be, for example, 185 sec/100cc to 210 sec/100cc. Within the above range, since the pores formed in the separator are sufficiently opened, ionic conductivity is excellent, and battery output and battery performance can be improved.

The lithium metal negative electrode structure may improve the sealing between the inorganic layer and the surface of the lithium metal negative electrode so that the porosity between the lithium metal negative electrode and the inorganic layer may be 0 to 10%, for example, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, 0 to 4%, 0 to 3%, 0 to 2%, or 0 to 1%. The porosity between the lithium metal negative electrode and the inorganic layer is within the above range, and the growth of lithium dendrites on the surface of the lithium metal negative electrode can be suppressed as much as possible.

The lithium metal negative electrode structure according to an embodiment can bind the separator coated with the inorganic layer to the surface of the lithium metal negative electrode through a rolling process through a rolling process, thereby improving surface uniformity, which is the biggest problem of the lithium metal negative electrode. , By improving the sealing of the inorganic layer and the surface of the lithium metal negative electrode, it can also contribute to improving the life performance and suppressing the fire or explosion of the cell due to the internal short circuit and by suppressing the uniform reaction and the growth of the lithium dendrite as much as possible.

2 is a diagram illustrating a battery stacking structure using a lithium metal anode structure according to an embodiment.

As shown in FIG. 2, the lithium metal negative electrode structure 10 and the positive electrode 20 may be directly stacked to assemble a pouch unit cell, and thus may be applied to various batteries. Here, the positive electrode 20 may have positive active material layers 21 disposed on both surfaces of the current collector 22 such as aluminum foil.

Hereinafter, a method of manufacturing a lithium metal anode structure according to an embodiment will be described.

The method of manufacturing the lithium metal negative electrode structure according to one embodiment includes the step of binding a separator to at least one surface of the lithium metal negative electrode using a rolling roll or a press, and the separator is coated on a porous substrate and the porous substrate. And an inorganic layer comprising inorganic nanoparticles having an average particle diameter of 5 to 200 nm, and the inorganic layer is positioned between the lithium metal negative electrode and the porous substrate.

3 is a diagram illustrating a method of manufacturing a lithium metal negative electrode structure using a rolling roll according to an embodiment.

As shown in FIG. 3, a separator including a porous substrate coated with an inorganic layer is bonded to at least one side, for example, both sides of a lithium metal anode using a rolling process.

The binding step may be performed by hot rolling or cold rolling.

Hot rolling may be performed at 30 to 90° C., for example, cold rolling may be performed at 20 to 30° C., for example, and binding is performed at a line pressure in the range of 50 kgf to 1000 kgf. In the section in which the uniformity of the surface is improved, the line pressure may be in the range of 200kgf to 500kgf, and in the case of hot rolling, even lower pressure may bring more improved binding force.

The lithium metal negative electrode structure obtained through such a rolling process can be easily applied to the existing battery manufacturing process without significant change, and thus has mass-producibility, and can be used for all-solid-state batteries in the future.

The manufacturing method of the lithium metal negative electrode structure using a rolling process is to improve the surface uniformity of the lithium metal negative electrode by bonding the separator coated with the inorganic layer to the surface of the lithium metal negative electrode, and improve the sealing of the inorganic layer and the lithium metal negative electrode surface. I can make it. Through this, it is possible to provide a lithium metal anode structure capable of improving battery life and stability by inducing a uniform reaction and suppressing the growth of lithium dendrites as much as possible.

An electrochemical device according to an embodiment includes the above-described lithium metal anode structure. The electrochemical device including the lithium metal anode structure may suppress growth of lithium resin and improve life and stability.

The electrochemical device may be a lithium secondary battery such as a lithium ion battery, a lithium polymer battery, a lithium metal battery, a lithium air battery, and a lithium solid state battery.

A lithium secondary battery according to an embodiment includes: a negative electrode including the above-described lithium metal negative electrode structure; An anode disposed opposite to the cathode; And an electrolyte disposed between the negative electrode and the positive electrode.

The negative electrode includes the lithium metal negative electrode structure described above. The lithium metal anode structure may be manufactured by the above-described manufacturing method.

In addition to the above-described lithium metal negative electrode structure, the negative electrode may further include a negative electrode active material material commonly used as a negative electrode active material for a lithium battery in the art. A commonly used negative electrode active material material may include, for example, at least one selected from the group consisting of lithium metal, a metal alloyable with lithium, a transition metal oxide, a non-transition metal oxide, and a carbon-based material.

For example, the metal alloyable with lithium is Si, Sn, Al, Ge, Pb, Bi, Sb Si-Y alloy (wherein Y is an alkali metal, alkaline earth metal, group 13 element, group 14 element, transition metal, rare earth Element or a combination element thereof, not Si), Sn-Y alloy (wherein Y is an alkali metal, alkaline earth metal, group 13 to 16 element, transition metal, rare earth element, or a combination element thereof, but not Sn) Etc. The element Y is Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Bi, S, It may be Se, Te, Po, or a combination thereof.

For example, the transition metal oxide may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, or the like.

For example, the non-transition metal oxide may be SnO ₂ , SiO _x (0<x≤2), or the like.

The carbon-based material may be crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon may be graphite such as amorphous, plate, flake, spherical or fibrous natural graphite or artificial graphite, and the amorphous carbon is soft carbon (low temperature calcined carbon) or hard carbon (hard carbon). carbon), mesophase pitch carbide, calcined coke, and the like.

When the above-described negative active material and carbon-based material are used together, the oxidation reaction of the silicon-based active material is suppressed, the SEI film is effectively formed to form a stable film, and the electrical conductivity is improved, thereby further improving the charging and discharging characteristics of lithium. .

A typical negative electrode active material may be coated on the surface of the above-described lithium metal negative electrode structure, or may be used in any other combination. For example, after preparing a negative electrode active material composition by mixing a negative electrode active material, a binder, and optionally a conductive agent in a solvent, it is molded into a certain shape, applied to the lithium metal negative electrode structure, or a copper foil, etc. It can be prepared by coating the whole and combined with a lithium metal negative electrode structure.

The binder used in the negative active material composition is a component that assists in binding of the negative active material to the conductive agent and bonding to the current collector, and is added in an amount of 1 to 50 parts by weight based on 100 parts by weight of the negative active material. For example, the binder may be added in a range of 1 to 30 parts by weight, 1 to 20 parts by weight, or 1 to 15 parts by weight based on 100 parts by weight of the negative active material. Examples of such a binder include polyvinylidene fluoride, polyvinylidene chloride, polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydride Roxypropylcellulose, recycled cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethylmethacrylate, polyaniline, acrylonitrile butadiene styrene, phenolic resin, epoxy resin, polyethylene Terephthalate, polytetrafluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, polyethylenesulfone, polyamide, polyacetal, polyphenylene oxide, polybutylene terephthalate, ethylene-propylene-diene terpolymer (EPDM ), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, and various copolymers.

The negative electrode may optionally further include a conductive agent in order to further improve electrical conductivity by providing a conductive path to the negative active material. As the conductive agent, anything generally used for lithium batteries may be used, and examples thereof include carbon-based materials such as carbon black, acetylene black, ketjen black, and carbon fiber (eg, vapor-grown carbon fiber); Metal-based materials such as metal powders such as copper, nickel, aluminum, and silver, or metal fibers; A conductive material containing a conductive polymer such as a polyphenylene derivative, or a mixture thereof can be used. The content of the conductive material can be appropriately adjusted and used. For example, the weight ratio of the negative active material and the conductive agent may be added in the range of 99:1 to 90:10.

As the solvent, N-methylpyrrolidone (NMP), acetone, water, and the like may be used. The content of the solvent is 1 to 10 parts by weight based on 100 parts by weight of the negative active material. When the content of the solvent is within the above range, the operation for forming the active material layer is easy.

In addition, the current collector is generally made to have a thickness of 3 to 500 µm. The current collector is not particularly limited as long as it has conductivity without causing a chemical change in the battery, for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel. Surface treatment with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. may be used. In addition, by forming fine irregularities on the surface, the bonding strength of the negative electrode active material may be strengthened, and may be used in various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics.

The prepared negative electrode active material composition may be directly coated on a lithium metal negative electrode structure, directly coated on a current collector, or cast on a separate support and then a negative electrode active material film peeled off from the support is laminated on a copper foil current collector to obtain a negative electrode plate. . The negative electrode is not limited to the shapes listed above, but may have a shape other than the above shape.

The negative active material composition may be used not only to manufacture an electrode of a lithium secondary battery, but also to be printed on a flexible electrode substrate and used to manufacture a printable battery.

Separately, in order to manufacture a positive electrode, a positive electrode active material composition in which a positive electrode active material, a conductive agent, a binder and a solvent are mixed is prepared.

As the positive electrode active material, any lithium-containing metal oxide may be used as long as it is commonly used in the art.

For example, Li _a A _1-b B _b D ₂ (in the above formula, 0.90≦a≦1.8, and 0≦b≦0.5); Li _a E _1-b B _b O _2-c D _c (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiE _2-b B _b O _4-c D _c (where 0≦b≦0.5, 0≦c≦0.05); Li _a Ni _1-bc Co _b B _c D _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, and 0<α≦2); Li _a Ni _1-bc Co _b B _c O _2-α F _α (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); Li _a Ni _1-bc Co _b B _c O _2-α F _α (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); Li _a Ni _1-bc Mn _b B _c D _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, 0<α≦2); Li _a Ni _1-bc Mn _b B _c O _2-α F _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, 0<α<2); Li _a Ni _1-bc Mn _b B _c O _2-α F _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, 0<α<2); Li _a Ni _b E _c G _d O ₂ (In the above formula, 0.90≦a≦1.8, 0≦b≦0.9, 0≦c≦0.5, and 0.001≦d≦0.1); Li _a Ni _b Co _c Mn _d GeO ₂ (In the above formula, 0.90≦a≦1.8, 0≦b≦0.9, 0≦c≦0.5, 0≦d≦0.5, and 0.001≦e≦0.1); Li _{a NiG b} O ₂ (in the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); Li _a CoG _b O ₂ (in the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); Li _{a MnG b} O ₂ (in the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); Li _a Mn ₂ G _b O ₄ (In the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); QO ₂ ; QS ₂ ; LiQS ₂ ; V ₂ O ₅ ; LiV ₂ O ₅ ; LiIO ₂ ; LiNiVO ₄ ; Li _(3-f) J ₂ (PO ₄ ) ₃ (0≦f≦2); Li _(3-f) Fe ₂ (PO ₄ ) ₃ (0≦f≦2); A compound represented by any one of the formulas of LiFePO _{4 can be used:}

In the above formula, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or combinations thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

The positive electrode active material is, for example, lithium cobalt oxide of _{LiCoO 2;} Lithium nickel oxide of the formula LiNiO _2; Lithium manganese oxides such as the formula Li _1+x Mn _2-x O ₄ (wherein x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , or LiMnO _2; Lithium copper oxide of the formula Li ₂ CuO _2; Lithium iron oxide of the formula LiFe ₃ O _4; Lithium vanadium oxide of the formula LiV ₃ O _8; Copper vanadium oxide of the formula Cu ₂ V ₂ O _7; Vanadium oxide of the formula V ₂ O _5; Lithium nickel oxide of the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3); Formula LiMn _2-x M _x O ₂ (where M = Co, Ni, Fe, Cr, Zn or Ta, and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (where M = Fe, Co, A lithium manganese composite oxide represented by Ni, Cu, or Zn); Lithium manganese oxide in which Li of the formula LiMn ₂ O ₄ is partially substituted with alkaline earth metal ions; Disulfide compounds; One or more iron molybdenum oxides of the formula Fe ₂ (MoO ₄ ) _{3 may be selected and used.}

Of course, one having a coating layer on the surface of the compound may be used, or a mixture of the compound and a compound having a coating layer may be used. This coating layer may contain a coating element compound of oxide, hydroxide, oxyhydroxide of coating element, oxycarbonate of coating element, or hydroxycarbonate of coating element. The compound constituting these coating layers may be amorphous or crystalline. As a coating element included in the coating layer, Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or a mixture thereof may be used. The coating layer forming process may be any coating method as long as the compound can be coated by a method that does not adversely affect the physical properties of the positive electrode active material by using these elements (e.g., spray coating, dipping method, etc.). Since the content can be well understood by those engaged in the relevant field, detailed description will be omitted.

For example, LiNiO ₂ , LiCoO ₂ , LiMn _x O _2x (x=1, 2), LiNi _1-x Mn _x O ₂ (0<x<1), LiNi _1-xy Co _x Mn _y O ₂ (0 ≤x≤0.5, 0≤y≤0.5), LiFeO ₂ , V ₂ O ₅ , TiS, MoS, etc. may be used.

In the positive electrode active material composition, the conductive agent, the binder, and the solvent may be the same as those of the negative electrode active material composition described above. In some cases, it is possible to form pores inside the electrode plate by adding a plasticizer to the positive electrode active material composition and the negative electrode active material composition. The contents of the positive electrode active material, the conductive agent, the binder, and the solvent are the levels commonly used in lithium batteries.

The positive electrode current collector has a thickness of 3 to 500 μm, and is not particularly limited as long as it has high conductivity without causing chemical changes to the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, Alternatively, a surface-treated aluminum or stainless steel surface with carbon, nickel, titanium, silver, or the like may be used. The current collector may increase the adhesion of the positive electrode active material by forming fine irregularities on its surface, and various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics are possible.

The prepared positive electrode active material composition may be directly coated and dried on a positive electrode current collector to prepare a positive electrode plate. Alternatively, a positive electrode plate may be manufactured by casting the positive active material composition on a separate support and then laminating a film obtained by peeling from the support on a positive electrode current collector.

The positive electrode and the negative electrode may be separated by a separator, and any of the separators may be used as long as they are commonly used in lithium batteries. Particularly, those having low resistance to ion migration of the electrolyte and excellent electrolyte-moisturizing ability are suitable. For example, as a material selected from glass fiber, polyester, Teflon, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), and combinations thereof, it may be in the form of a non-woven fabric or a woven fabric. The separator has a pore diameter of 0.01 to 10 µm, and a thickness of 5 to 300 µm is generally used.

The lithium salt-containing non-aqueous electrolyte consists of a non-aqueous electrolyte and lithium. As the non-aqueous electrolyte, a non-aqueous electrolyte, a solid electrolyte, an inorganic solid electrolyte, or the like is used.

Examples of the non-aqueous electrolyte solution include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyl Low lactone, 1,2-dimethoxy ethane, tetrahydrofuran, 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethylformamide, acetonitrile, nitromethane, methyl formate, Methyl acetate, phosphoric acid tryster, trimethoxy methane, dioxolane derivative, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, ether, An aprotic organic solvent such as methyl pyropionate and ethyl propionate may be used.

Examples of the organic solid electrolyte include polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate ester polymers, poly agitation lysine, polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, A polymer or the like containing an ionic dissociating group may be used.

As the inorganic solid electrolyte, for example, Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides, and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH, Li ₃ PO ₄ -Li ₂ S-SiS _{2 may be used.}

Any of the lithium salts can be used as long as they are commonly used in lithium batteries, and as a material that is good soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , _{LiPF 6, LiCF 3 SO 3,} LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, F 2 LiNO 4 S 2, One or more materials such as lithium chloroborate, lower aliphatic lithium carboxylic acid, lithium tetraphenylborate, and imide may be used.

Lithium secondary batteries can be classified into lithium-ion batteries, lithium-ion polymer batteries, and lithium polymer batteries according to the type of separator and electrolyte used, and can be classified into cylindrical, rectangular, coin-type, pouch-type, etc. depending on their shape. Depending on the size, it can be divided into bulk type and thin film type.

Since methods of manufacturing these batteries are widely known in this field, detailed descriptions are omitted.

The electrochemical device may be a lithium metal battery.

The lithium metal battery can be manufactured in a stack type in which a positive electrode and a lithium metal negative electrode structure are stacked, and alternatively, it can be manufactured in a jelly roll type by winding the positive electrode and lithium metal negative electrode structure in a roll form rather than a stack type. Do.

9 schematically shows the structure of a lithium metal battery according to an embodiment.

As shown in FIG. 9, the lithium metal battery 11 includes a positive electrode 13, a negative electrode 12 including a lithium metal negative electrode structure, and a separator 14. The positive electrode 13, the negative electrode 12, and the separator 14 are wound or folded to be accommodated in the battery case 15. Subsequently, an electrolyte is injected into the battery case 55 and sealed with a cap assembly 16 to complete the lithium metal battery 11. The battery case may be a cylindrical shape, a square shape, a thin film type, or the like. For example, the lithium metal battery may be a large thin film type battery. The lithium metal battery may be a lithium ion battery.

The lithium metal battery has excellent capacity and life characteristics and can be used not only for battery cells used as power sources for small devices, but also for medium and large battery packs or battery modules including a plurality of battery cells used as power sources for medium and large devices. It can also be used as a battery. Examples of the medium and large-sized devices include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and the like.

Exemplary embodiments are described in more detail through the following examples and comparative examples. However, the embodiments are for illustrative purposes only, and the scope of the present invention is not limited thereto.

Example 1: Preparation of lithium metal negative electrode structure

First, obtained by mixing alumina nanoparticles with an average particle diameter of 30 nm and an ACN (Acetonitrile) solution containing 6% by weight polyacrylonitrile (PAN) as a polymer binder so that the alumina nanoparticles:PAN weight ratio is 94:6. The composition was coated on a polyethylene substrate and vacuum-dried at 70° C. for 12 hours to prepare a separator in which an inorganic layer was formed on the end face of the polyethylene substrate.

The inorganic layer of the separator is disposed on both sides of a roll-rolled lithium thin film (thickness 20 μm) of Japanese Honjo Corporation so that the inorganic layer of the separator is in contact with the lithium thin film, and the separator is bound to the surface of the lithium thin film through a rolling process as shown in FIG. A metal cathode structure was prepared. At this time, hot rolling was performed, the temperature was 55°C, and the line pressure was 250kgf.

Comparative Example 1: Conventional lithium metal anode

A roll-rolled lithium thin film (20 µm in thickness) manufactured by Honjo, Japan was used as Comparative Example 1.

Evaluation Example 1: Surface observation and surface roughness measurement of a lithium metal negative electrode

4A is a photograph of a lithium metal negative electrode of Comparative Example 1, FIG. 4B is a photograph of a lithium metal negative electrode structure of Example 1, and FIG. 4C is a lithium metal negative electrode with improved surface uniformity in the lithium metal negative electrode structure of Example 1. This is a picture showing.

As shown in FIGS. 4A to 4C, the surface of the lithium metal negative electrode to which the inorganic layer-coated separator was bonded (FIG. 4c) was visually confirmed that the surface was smoother than that of the conventional lithium metal negative electrode surface (FIG. 4a ). .

More specifically, in order to confirm the surface roughness of the surface of these lithium metal negative electrodes, surface observation and surface roughness (Ra) of the lithium metal negative electrode of Comparative Example 1 and the lithium metal negative electrode in the lithium metal negative electrode structure of Example 1 were observed using a Keyence microscope. ) Was measured and the results are shown in FIGS. 5 and 6, respectively.

5 and 6, in the case of the conventional lithium metal anode of Comparative Example 1, the surface roughness (Ra) value was 1.6, but the lithium metal anode structure of Example 1 was bonded to the inorganic layer through a rolling process. After that, it could be seen that it was remarkably reduced to 0.4, and a uniform surface was confirmed in the mapping result and the optical microscope.

Example 2: Manufacture of lithium metal battery

The lithium metal negative electrode structure according to Example 1 was used as a negative electrode, and the positive electrodes were sequentially stacked, and then put in an aluminum pouch and vacuum-packed to prepare a lithium metal battery.

Here, the positive electrode was prepared as follows and prepared by sufficiently impregnating a DME (1,2-dimethoxyethane) electrolyte in which 3.5M LiFSI (Lithium bis(fluorosulfonyl)imide) was dissolved in advance. To prepare a positive electrode, first, LiNiMnCoO ₂ , a conductive agent (Super-P; Timcal Ltd.), polyvinylidene fluoride (PVdF), and N-pyrrolidone were mixed to obtain a positive electrode composition. In the positive electrode composition, _{the mixing weight ratio of LiNiMnCoO 2} , the conductive agent and PVDF was 96:2:2. The positive electrode composition was coated on an aluminum foil (thickness: about 12 μm), and the coated electrode plate was dried at 110° C. under vacuum to prepare a positive electrode.

Comparative Example 2: Manufacture of lithium metal battery

A lithium metal battery was manufactured in the same manner as in Example 2, except that the lithium metal negative electrode according to Comparative Example 1 was used as the negative electrode.

Evaluation Example 2: Charge/discharge characteristics and life evaluation

For the lithium metal batteries according to Example 2 and Comparative Example 2, after two formation cycles at a current of 0.05C rate, CC-CV charging and discharging was performed up to 200 times at a current of 0.5C rate.

The results of measuring the discharge capacity for each cycle of the lithium metal batteries according to Example 2 and Comparative Example 2 are shown in FIG. 7. In addition, the results of measuring the discharge capacity/charge capacity efficiency for each cycle, that is, Coulomb efficiency, of lithium metal batteries according to Example 2 and Comparative Example 2 are shown in FIG. Here, the discharge capacity/charge capacity efficiency is calculated from the following calculation formula 1.

<Calculation 1>

Coulomb efficiency[%]=[discharge capacity in each cycle / charge capacity in each cycle] ×100

As shown in FIGS. 7 and 8, it can be seen that the lithium metal battery of Example 2 has improved discharge capacity and lifetime characteristics for each cycle compared to the lithium metal battery of Comparative Example 2. In addition, it was confirmed that the internal short-circuit phenomenon was also significantly suppressed at the end of the life.

In the above, a preferred embodiment according to the present invention has been described with reference to the drawings and embodiments, but this is only illustrative, and various modifications and other equivalent embodiments are possible from those of ordinary skill in the art. You will be able to understand. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims (38)

Lithium metal negative electrode; And
As a separator attached to at least one surface of the lithium metal negative electrode, the separator comprises a porous substrate and an inorganic layer including inorganic nanoparticles having an average particle diameter of 5 to 200 nm coated on the porous substrate, and the inorganic layer is the A separator positioned between the lithium metal negative electrode and the porous substrate;
Lithium metal anode structure comprising a. The method of claim 1,
The lithium metal anode structure is a lithium metal anode structure in a rolled state obtained by a rolling process. The method of claim 1,
A lithium metal negative electrode structure having a surface roughness (Ra) of 1 or less on the surface of the lithium metal negative electrode. The method of claim 1,
A lithium metal negative electrode structure having a surface roughness (Ra) of 0.5 or less on the surface of the lithium metal negative electrode. The method of claim 1,
A lithium metal negative electrode structure having a porosity of 0 to 10% between the lithium metal negative electrode and the inorganic layer. The method of claim 1,
A lithium metal negative electrode structure having a porosity of 0 to 5% between the lithium metal negative electrode and the inorganic layer. The method of claim 1,
The average particle diameter of the inorganic nanoparticles is a lithium metal negative electrode structure of 5 to 200 nm. The method of claim 1,
The inorganic nanoparticles are lithium metal negative electrode structures comprising a ceramic material. The method of claim 8,
The ceramic material is alumina (Al ₂ O ₃ ), silica (SiO ₂ ), zinc oxide, zirconium oxide (ZrO ₂ ), zeolite, titanium oxide (TiO ₂ ), barium titanate (BaTiO ₃ ), strontium titanate ( SrTiO _3), calcium titanate (CaTiO _3), aluminum borate, iron oxide, calcium carbonate, barium carbonate, lead oxide, tin oxide, cerium oxide, calcium oxide, sasanhwasam manganese, magnesium oxide, niobium oxide, tantalum oxide, tungsten oxide, Antimony, aluminum phosphate, calcium silicate, zirconium silicate, ITO (tin-containing indium oxide), titanium silicate, montmorillonite, saponite, vermiculite, hydrotalcite, kaolinite, carnemite, margadiite, and kenyito Lithium metal anode structure comprising at least one. The method of claim 1,
The inorganic nanoparticles are lithium metal anode structure comprising a solid electrolyte material. The method of claim 10,
The solid electrolyte material is a lithium metal negative electrode structure comprising an inorganic lithium ion conductor. The method of claim 11,
The inorganic lithium ion conductor is a garnet type compound, an azirodite type compound, a lithium super-ion-conductor (LISICON) compound, a Na super ionic conductor-like (NASICON) compound, a lithium nitride, Lithium metal anode structure comprising at least one selected from the group consisting of lithium hydride, perovskite, lithium halide, and sulfide-based compounds. The method of claim 11,
The inorganic lithium ion conductor is Garnet-based ceramics Li _3+x La ₃ M ₂ O ₁₂ (0≤x≤5, M = W, Ta, Te, at least one of Nb and Zr), doped garnet (Garnet ) ceramics _{Li 7-3x M 'x La 3 M} 2 O 12 (0 <x≤1, MW, Ta, Te, Nb, and wherein at least one of Zr, M' = Al, Ga , Nb, Ta, Fe , Zn, Y, Sm, and at least one of Gd), Li _1+x+y Al _x Ti _2-x Si _y P _3-y O ₁₂ (0<x<2, 0≤y<3), BaTiO ₃ , Pb(Zr,Ti)O ₃ (PZT), Pb _1-x La _x Zr _1-y Ti _y O ₃ (PLZT)(O≤x<1, O≤y<1),Pb(Mg _1/3 Nb _2/3 )O ₃ -PbTiO ₃ (PMN-PT), lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ ,0<x<2,0<y<3) , Lithium aluminum titanium phosphate (Li _x Al _y Ti _z (PO ₄ ) 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 (O≤x≤1, O≤y≤1), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0<x<2, 0<y <3), lithium germanium thiophosphate (LixGeyPzSw, 0<x<4, 0<y<1, 0<z<1, 0<w<5), lithium nitride (Li _x N _y , 0<x<4) , 0<y<2), SiS ₂ (Li _x Si _y S _z , 0≤<3,0<y<2, 0<z<4) series glass, P ₂ S ₅ (Li _x P _y S _z , 0≤x<3, 0<y<3, 0<z<7) series glass, Li _3x La _2/3-x TiO ₃ (0≤x≤1/6), Li ₇ La ₃ Zr ₂ O ₁₂ , Li _1+y Al _y Ti _2-y (PO ₄ ) ₃ (0≤y≤1) and Li _1+z Al _z Ge _2-z (PO ₄ ) ₃ (0≤z≤1), Li ₂ O, LiF, LiOH, Li ₂ C O ₃ , LiAlO ₂ , Li ₂ O-Al ₂ O ₃ -SiO ₂ -P ₂ O ₅ -TiO ₂ -GeO ₂ -based ceramics, Li ₁₀ GeP ₂ S ₁₂ , Li _3.25 Ge _0.25 P _0.75 S ₄ , Li ₃ PS ₄ , Li ₆ PS ₅ Br, Li ₆ PS ₅ Cl, Li ₇ PS ₅ , Li ₆ PS ₅ I, Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ , LiTi ₂ (PO ₄ ) ₃ , LiGe ₂ (PO ₄ ) ₃ , LiHf ₂ (PO ₄ ) ₃ , LiZr ₂ (PO ₄ ) ₃ , Li ₂ NH ₂ , Li ₃ (NH ₂ ) ₂ I, LiBH ₄ , LiAlH ₄ , LiNH ₂ , Li _0.34 La _0.51 TiO _2.94 , LiSr ₂ Ti ₂ NbO ₉ , Li _0.06 La _0.66 Ti _0.93 Al _0.03 O ₃ , Li _0.34 Nd _0.55 TiO ₃ , Li ₂ CdCl ₄ , Li ₂ MgCl ₄ , Li ₂ ZnI ₄ , Li ₂ CdI ₄ , Li _4.9 Ga _0.5+δ La ₃ Zr _1.7 W _0.3 O ₁₂ (0≤δ<1.6), Li _4.9 Ga _0.5+δ La ₃ Zr _1.7 W _0.3 O ₁₂ (1.7≤δ≤2.5), Li _5.39 Ga _0.5+δ La ₃ Zr _1.7 W _0.3 O ₁₂ (0≤δ≤1.11), lithium phosphorus sulfide (Li ₃ PS ₄ ), lithium tin sulfide (Li ₄ SnS ₄ ), lithium phosphorus sulfur chloride iodide (Li ₆ PS ₅ Cl _0.9 I _0.1 ), Lithium tin phosphorus sulfide (Li ₁₀ SnP ₂ S ₁₂ ), One lithium metal negative electrode selected from the group consisting of Li ₂ S, Li ₂ SP ₂ S ₅ , Li ₂ S-SiS ₂ , Li ₂ S-GeS ₂ , Li ₂ SB ₂ S ₅ , and Li ₂ S-Al ₂ S ₅ Structure. The method of claim 1,
The content of the inorganic nanoparticles is at least 10% by weight or more based on the total weight of the inorganic layer lithium metal negative electrode structure. The method of claim 1,
The content of the inorganic nanoparticles is a lithium metal negative electrode structure of 70 to 98% by weight based on the total weight of the inorganic layer. The method of claim 1,
The inorganic layer is a lithium metal negative electrode structure further comprising an organic binder. The method of claim 16,
The inorganic layer is a lithium metal anode structure having a form in which the inorganic nanoparticles are dispersed in a matrix made of the organic binder. The method of claim 16,
The organic binder is polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene chloride, polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, polyurethane, polyvinyl alcohol, Carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethylmethacrylate, polyaniline, acrylic Lonitrile butadiene styrene, phenol resin, epoxy resin, polyethylene terephthalate, polytetrafluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, polyethylene sulfone, polyamide, polyacetal, polyethylene oxide, polyethylene glycol diacrylate At least one selected from polyethylene glycol monoacrylate, polyphenylene oxide, polybutylene terephthalate, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, and copolymers thereof Lithium metal anode structure comprising a. The method of claim 16,
The content of the organic binder is 50 to 99% by weight based on the total weight of the inorganic nanoparticles and the organic binder lithium metal anode structure. The method of claim 1,
The thickness of the inorganic layer is a lithium metal negative electrode structure of 0.1 to 10 ㎛. The method of claim 1,
The separator is a lithium metal negative electrode structure further comprising a polymer coating layer on the inorganic layer. The method of claim 21,
The polymer coating layer is polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene chloride, polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, polyurethane, polyvinyl alcohol, Carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethylmethacrylate, polyaniline, acrylic Lonitrile butadiene styrene, phenol resin, epoxy resin, polyethylene terephthalate, polytetrafluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, polyethylene sulfone, polyamide, polyacetal, polyethylene oxide, polyethylene glycol diacrylate At least one selected from polyethylene glycol monoacrylate, polyphenylene oxide, polybutylene terephthalate, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, and copolymers thereof Lithium metal anode structure comprising a. The method of claim 1,
The porous substrate is a lithium metal negative electrode structure of a polyolefin substrate. The method of claim 23,
The polyolefin substrate is at least one copolymer selected from polyethylene, polypropylene, polybutylene, polypentene, polyhexene, polyoctene, ethylene, propylene, butene, pentene, 4-methylpentene, hexene and octene, a mixture thereof, or a mixture thereof. Lithium metal negative electrode structure comprising a combination. The method of claim 1,
The thickness of the porous substrate is 1㎛ 50㎛ lithium metal negative electrode structure. The method of claim 1,
The lithium metal negative electrode is a lithium metal negative electrode structure in which a lithium thin film is rolled on both sides of a copper foil. The method of claim 1,
The thickness of the lithium metal negative electrode is 0.1 to 60㎛ lithium metal negative electrode structure. A negative electrode for an electrochemical device comprising the lithium metal negative electrode structure according to any one of claims 1 to 27. An electrochemical device comprising the lithium metal anode structure according to any one of claims 1 to 27. The method of claim 29,
The electrochemical device includes at least one selected from a battery, a storage battery, a supercapacitor, a fuel cell, a sensor, and a color change device. A lithium secondary battery comprising the lithium metal negative electrode structure according to any one of claims 1 to 27. anode; And a negative electrode including the lithium metal negative electrode structure according to any one of claims 1 to 27. The method of claim 32,
The positive electrode is Li _a A _1-b B _b D ₂ (in the above formula, 0.90≦a≦1.8, and 0≦b≦0.5); Li _a E _1-b B _b O _2-c D _c (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiE _2-b B _b O _4-c D _c (where 0≦b≦0.5, 0≦c≦0.05); Li _a Ni _1-bc Co _b B _c D _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, and 0<α≦2); Li _a Ni _1-bc Co _b B _c O _2-α F _α (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); Li _a Ni _1-bc Co _b B _c O _2-α F _α (in the above formula, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); Li _a Ni _1-bc Mn _b B _c D _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, 0<α≦2); Li _a Ni _1-bc Mn _b B _c O _2-α F _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, 0<α<2); Li _a Ni _1-bc Mn _b B _c O _2-α F _α (in the above formula, 0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05, 0<α<2); Li _a Ni _b E _c G _d O ₂ (In the above formula, 0.90≦a≦1.8, 0≦b≦0.9, 0≦c≦0.5, and 0.001≦d≦0.1); Li _a Ni _b Co _c Mn _d GeO ₂ (In the above formula, 0.90≦a≦1.8, 0≦b≦0.9, 0≦c≦0.5, 0≦d≦0.5, and 0.001≦e≦0.1); Li _{a NiG b} O ₂ (in the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); Li _a CoG _b O ₂ (in the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); Li _{a MnG b} O ₂ (in the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); Li _a Mn ₂ G _b O ₄ (In the above formula, 0.90≦a≦1.8 and 0.001≦b≦0.1); QO ₂ ; QS ₂ ; LiQS ₂ ; V ₂ O ₅ ; LiV ₂ O ₅ ; LiIO ₂ ; LiNiVO ₄ ; Li _(3-f) J ₂ (PO ₄ ) ₃ (0≦f≦2); Li _(3-f) Fe ₂ (PO ₄ ) ₃ (0≦f≦2); Including at least one compound selected from the group consisting of LiFePO _4,
In the above formula, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or combinations thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a lithium metal battery in combination thereof. Including the step of binding the separator to at least one side of the lithium metal negative electrode using a rolling roll or press,
The separator includes a porous substrate and an inorganic layer including inorganic nanoparticles having an average particle diameter of 5 to 200 nm coated on the porous substrate, and wherein the inorganic layer is positioned between the lithium metal negative electrode and the porous substrate. A method of manufacturing a lithium metal negative electrode structure according to any one of claims 1 to 19. The method of claim 34,
The bonding step is a method of manufacturing a lithium metal negative electrode structure performed by hot rolling or cold rolling. The method of claim 34,
The hot rolling is performed at 40 to 80 °C, and the cold rolling is performed at 20 to 30 °C. The method of claim 34,
A method of manufacturing a lithium metal negative electrode structure in which the line pressure in the binding step is in the range of 50kgf to 1000kgf. A method of manufacturing a lithium metal battery comprising the step of laminating a positive electrode and a negative electrode including the lithium metal negative electrode structure according to any one of claims 1 to 27.

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