Lithium metal battery and method for manufacturing lithium metal battery

Abstract

Lithium metal batteries and methods of making lithium metal batteries are disclosed. The lithium metal battery includes: a negative electrode current collector; a protective layer on the negative electrode current collector and including a porous carbon structure and lithium-loving particles dispersed in the porous carbon structure; a composite isolation layer on the protective layer and including a separator and a lithium-phobic metal layer on the separator; and a positive electrode on the composite isolation layer. The positive electrode comprises a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer includes a positive electrode active material represented by LiaNi1-b-cCobXcO2-d, where 0.90 < = a < = 1.8, 0 < = b < = 0.2, 0 < = c < = 0.2, 0.8 < = 1-b-c < = 0.99, and 0 < = d < = 0.2, and X includes at least one of Al, Mn, and a combination thereof.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2024-0111847, filed on August 21, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] Examples of this disclosure relate to lithium metal batteries and methods of manufacturing lithium metal batteries, and more specifically, to lithium metal batteries including high-capacity positive electrodes and methods of manufacturing lithium metal batteries. Background Technology

[0003] Carbon-based negative electrode active materials, such as graphite, are commonly used in currently commercially available lithium-ion batteries. These materials typically do not exhibit volume changes during charging and discharging, which improves the stability of lithium-ion batteries, but they have low capacity, thus potentially requiring negative electrode active materials with higher capacity.

[0004] As a negative electrode active material, lithium metal has a theoretical capacity that is substantially larger than that of carbon-based negative electrode active materials. During charging and discharging, lithium metal undergoes side reactions with the electrolyte to form dendrites on its surface, and these dendrites can grow to cause short circuits between the positive and negative electrodes. As a result, the lifespan characteristics of lithium metal batteries, which include lithium metal, are reduced. Summary of the Invention

[0005] Some example embodiments of this disclosure include high-capacity lithium metal batteries that reduce or suppress lithium dendrites and have desired or improved lifetime characteristics.

[0006] Some embodiments of this disclosure provide a method for manufacturing a high-capacity lithium metal battery that reduces or suppresses lithium dendrites and has desired or improved lifetime characteristics.

[0007] According to some exemplary embodiments of this disclosure, a lithium metal battery may include: a negative electrode current collector; a protective layer on the negative electrode current collector, wherein the protective layer includes a porous carbon structure and a plurality of lithium-affinity particles dispersed in the porous carbon structure; a composite separator layer on the protective layer, wherein the composite separator layer includes a separator and a lithium-phobic metal layer on a first surface of the separator, wherein the lithium-phobic metal layer faces the protective layer; and a positive electrode on the composite separator layer. The positive electrode may include a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector. The positive electrode active material layer may include materials composed of Li a Ni 1-b- c Co b X c O 2-dThe positive electrode active material is represented by (where 0.90≤a≤1.8, 0≤b≤0.2, 0≤c≤0.2, 0.8≤1-bc≤0.99 and 0≤d≤0.2). X may include at least one of Al, Mn and combinations thereof.

[0008] According to some example embodiments of this disclosure, a lithium metal battery may include: a negative electrode; a positive electrode; an electrolyte layer between the negative electrode and the positive electrode; and a composite separator layer impregnated in the electrolyte layer. The negative electrode may include a negative electrode current collector and a protective layer on the negative electrode current collector. The composite separator layer may include a separator and a lithium-repellent metal layer on a first surface of the separator. The lithium-repellent metal layer may face the protective layer. The protective layer may include a porous carbon structure and a plurality of lithium-philic particles dispersed in the porous carbon structure. The electrolyte layer may include a gel-polymer electrolyte.

[0009] According to some example embodiments of this disclosure, a method of manufacturing a lithium metal battery may include: preparing a composite separator by forming a lithium-repellent metal layer on a first surface of a separator; preparing a protective layer by performing an electrospinning process using a mixed solution of a polymer and a metal precursor compound; forming a stack by stacking (e.g., sequentially stacking) a negative electrode current collector, a protective layer, a composite separator, and a positive electrode; providing an electrolyte solution to the stack, wherein the composite separator is impregnated in the electrolyte solution; and thermally crosslinking the electrolyte solution to form an electrolyte layer. Attached Figure Description

[0010] Figure 1 A simplified conceptual diagram illustrating a lithium metal battery according to some example embodiments of the present disclosure is shown.

[0011] Figure 2 and Figure 3 It shows Figure 1 An enlarged sectional view of part M.

[0012] Figure 4 A simplified conceptual diagram illustrating a crosslinked polymer structure according to some example embodiments of the present disclosure is shown.

[0013] Figures 5 to 7 A conceptual diagram illustrating a lithium metal battery according to some example embodiments of the present disclosure is shown.

[0014] Figures 8A to 8E A cross-sectional view is shown illustrating a method for manufacturing a lithium metal battery according to some example embodiments of the present disclosure.

[0015] Figure 9 A photograph comparing the composite isolation layer of Example 1 with the diaphragm of Comparative Example 1 is shown.

[0016] Figure 10An image showing the surface analysis results of the protective layer in Example 1 is displayed.

[0017] Figure 11 A graph showing the positive electrode capacity and coulombic efficiency of Example 1 and Comparative Example 1 is presented.

[0018] Figure 12 A graph showing the positive electrode capacity and coulombic efficiency of Example 2 and Comparative Example 2 is presented.

[0019] Figure 13 Images comparing the negative electrode of Example 1 with the negative electrode of Comparative Example 1 after cycling are shown.

[0020] Figure 14 This is a flowchart illustrating a method for manufacturing a lithium metal battery according to an example embodiment. Detailed Implementation

[0021] To fully understand the structure and effects of this disclosure, some exemplary embodiments of the disclosure have been described with reference to the accompanying drawings. However, it should be noted that this disclosure is not limited to the following exemplary embodiments and can be implemented in various forms. Rather, the exemplary embodiments are provided merely to disclose the disclosure and to allow those skilled in the art to fully understand its scope.

[0022] In this specification, it is understood that when an element is referred to as being "on" another element, the element may be "directly on" said other element, or there may be an intervening element between them. In the accompanying drawings, the thickness of some components may be exaggerated for more effective explanation of the technical content. Throughout the specification, the same reference numerals denote the same elements.

[0023] Unless otherwise specified in this specification, singular expressions may include plural expressions. Furthermore, unless otherwise specified, the phrase "A or B" may mean "A but not B," "B but not A," and "A and B." The terms "including / comprises" and / or "variations thereof" as used in this specification do not exclude the presence or addition of one or more other components.

[0024] In this specification, the term "combination thereof" may refer to mixtures, stacks, complexes, copolymers, alloys, blends, or reaction products.

[0025] In this specification, the term "metal" may include metals or metalloids (such as silicon and germanium) that are in an elemental or ionic state.

[0026] In this specification, the term "alloy" may refer to a mixture of two or more metals.

[0027] In this specification, the term "positive electrode active material" may refer to a positive electrode material capable of lithiation and delithiation.

[0028] In this specification, the term "negative electrode active material" may refer to a negative electrode material capable of lithiation and delithiation.

[0029] In this specification, the terms "lithiation" and "performing lithiation" can refer to the process of adding lithium to the positive electrode active material or the negative electrode active material.

[0030] In this specification, the terms "delithiation" and "performing delithiation" can refer to the process of removing lithium from the positive electrode active material or the negative electrode active material.

[0031] In this specification, the terms “charging” and “performing a charge” can refer to the process by which a battery provides electrochemical energy.

[0032] In this specification, the terms “discharge” and “performing a discharge” can refer to the process of removing electrochemical energy from a battery.

[0033] In this specification, the term "positive electrode" may refer to an electrode that undergoes electrochemical reduction and lithiation during the discharge process.

[0034] In this specification, the term "negative electrode" may refer to an electrode that undergoes electrochemical oxidation and delithiation during the discharge process.

[0035] When the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, it is intended that the relevant numerical value include a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​within that range, such as increments of 0.1%.

[0036] Figure 1 This is a simplified conceptual diagram illustrating a lithium metal battery according to some example embodiments of the present disclosure. (Refer to...) Figure 1 A lithium metal battery may include a positive electrode (PEL), a negative electrode (NEL), a separator (SEP), and an electrolyte layer (ETL).

[0037] Lithium metal can be included as a negative electrode active material in lithium metal batteries. In lithium metal batteries, a lithium-containing metal layer can be deposited or dissolved during the charging and discharging process. This lithium-containing metal layer can form on the top surface of the negative electrode current collector COL1 and in the negative electrode matrix layer, as will be discussed below. Repeated charging and discharging of lithium metal batteries can result in the lithium-containing metal layer including residual impurities in the electrode and electrolyte deposition products.

[0038] Because the lithium-containing metal layer contains such impurities, it may have a generally rough and hard surface. Lithium dendrites can deposit on this rough surface. During charging and discharging, these dendrites can grow almost continuously, causing a short circuit between the positive electrode (PEL) and the negative electrode (NEL). Furthermore, during charging, the uneven dendrite growth of lithium on the negative electrode (NEL) can easily lead to damage within the battery and cause significant expansion of the battery volume, posing challenges for long-term operation.

[0039] The positive electrode PEL and the negative electrode NEL can be separated from each other by a separator SEP. The separator SEP can be disposed between the positive electrode PEL and the negative electrode NEL. The separator SEP can be impregnated with electrolyte. In an example embodiment, in addition to the separator SEP, the electrolyte can also be impregnated in the positive electrode PEL and the negative electrode NEL. In an example embodiment, the electrolyte layer ETL can impregnate not only the separator SEP, but also the positive electrode PEL and the negative electrode NEL.

[0040] The electrolyte layer (ETL) can serve as the medium through which lithium ions are transported between the positive electrode (PEL) and the negative electrode (NEL). Lithium ions in the ETL can cross the separator (SEP) to move toward either the positive electrode (PEL) or the negative electrode (NEL).

[0041] Negative electrode NEL Reference Figure 1 The negative electrode NEL for a lithium metal battery may include a negative electrode current collector COL1 and a protective layer PTL on the negative electrode current collector COL1. The negative electrode current collector COL1 may have a layer formed thereon... Figure 3 The reference surface of the lithium deposition layer LPL shown is described below. The negative electrode current collector COL1 may comprise a material that is substantially non-reactive with lithium, such as a material that does not form alloys or compounds with lithium. For example, the negative electrode current collector COL1 may comprise at least one of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The negative electrode current collector COL1 may have a thickness in the range of about 1 μm to about 20 μm, for example, in the range of about 5 μm to about 15 μm or about 7 μm to about 10 μm.

[0042] The negative electrode current collector COL1 can be formed from one of the aforementioned metals, an alloy of two or more of the aforementioned metals, or a coating material, or may include one of the aforementioned metals, an alloy of two or more of the aforementioned metals, or a coating material. The negative electrode current collector COL1 can have, for example, a plate shape or a foil shape. In an example embodiment, the negative electrode current collector COL1 may be omitted.

[0043] Figure 2 and Figure 3It shows Figure 1 An enlarged sectional view of part of the "M". (Refer to...) Figure 1 and Figure 2 The protective layer PTL may include a porous carbon structure CNF and lithiophilic particles SNP dispersed in the porous carbon structure CNF.

[0044] Porous carbon structure CNFs can include carbon. For example, porous carbon structure CNFs can include three-dimensional carbon nanofibers. Porous carbon structure CNFs may include a second pore, POR2. Porous carbon structure CNFs can have a porosity in the range of about 40% to about 80% or about 50% to about 80%. The second pore, POR2, of the porous carbon structure CNF can be substantially filled with a gel-polymer electrolyte, GPE, which will be discussed below.

[0045] Lithophile nanoparticles (SNPs) may include a lithiophilic metal. The lithiophilic metal may include a metal with a high affinity for lithium. The lithiophilic metal can effectively adsorb lithium ions onto its surface. The lithiophilic metal can contribute to substantially uniform electrodeposition of lithium. Lithophile nanoparticles (SNPs) may include at least one of silver (Ag), gold (Au), copper (Cu), tin (Sn), and bismuth (Bi). For example, a lithiophile nanoparticle (SNP) may be or include silver nanoparticles.

[0046] The protective layer PTL can have a thickness TK3 ranging from about 1 μm to about 100 μm or from about 1 μm to about 50 μm. Increasing the thickness TK3 of the protective layer PTL allows for the accommodation of a larger number of lithium ions, thereby increasing the battery's energy density and capacity. However, when the thickness TK3 of the protective layer PTL exceeds about 100 μm, the battery resistance and impedance may increase, potentially reducing overall efficiency.

[0047] Lithophilic particles (SNPs) in the protective PTL layer can induce temporary coupling of lithium ions during the charging and discharging of lithium metal batteries, thereby facilitating the electrodeposition of lithium metal.

[0048] Lithophilic particles (SNPs) can be or include lithium-miscible inorganic materials to facilitate lithium electrodeposition in porous carbon structures (CNFs). Lithophilic particles (SNPs) can reduce, inhibit, or delay dendrite growth.

[0049] Lithophilic particles (SNPs) can act as seed crystals to form solid solutions with lithium during lithium deposition and reduce interfacial capacity to promote a substantially uniform lithium distribution.

[0050] Reference Figure 3In lithium metal batteries, a lithium deposition layer (LPL) can be formed after initial cycling. Following this initial cycling, the negative electrode (NEL) of the lithium metal battery can further include the lithium deposition layer (LPL). The lithium deposition layer (LPL) can be positioned between the negative electrode current collector (COL1) and the electrolyte layer (ETL), which will be discussed below.

[0051] The charge of a lithium metal battery can cause lithium metal to be plated (or electroplated) onto the negative electrode current collector COL1, which can cause... Figure 3 The formation of the lithium deposition layer LPL shown is illustrated. The lithium deposition layer LPL may include lithium metal or a lithium alloy. The lithium alloy may be or include an alloy of lithium with a metal that can be alloyed with lithium. For example, the lithium alloy may include at least one of lithium-silver alloy, lithium-zinc alloy, lithium-magnesium alloy, and lithium-tin alloy.

[0052] The lithium deposition layer (LPL) can have a thickness of, for example, equal to or less than about 50 μm, equal to or less than about 40 μm, equal to or less than about 35 μm, equal to or less than about 30 μm, about 1 μm to about 50 μm, about 1 μm to about 40 μm, about 5 μm to about 40 μm, about 1 μm to about 35 μm, or about 10 μm to about 35 μm. When the thickness of the lithium deposition layer (LPL) falls within the above ranges, the lithium metal battery can have an improved energy density.

[0053] According to the example embodiment, the lithium deposition layer LPL at maximum charge can have a thickness equal to or less than about 35 μm, equal to or less than about 30 μm, equal to or less than about 28 μm, about 10 μm to about 35 μm, about 10 μm to about 30 μm, or about 10 μm to about 28 μm.

[0054] Return to reference Figure 3 Lithium can be plated (or electroplated) not only in the lithium deposition layer LPL, but also in the protective layer PTL. Therefore, a lithium-plated LPP can be formed in the protective layer PTL. As discussed above, the porous carbon structure CNF can include multiple secondary pores (POR2). Therefore, the porous carbon structure CNF of the protective layer PTL can provide space for lithium to be plated (or electroplated) when the lithium metal battery is charged.

[0055] The protective layer PTL can be constructed as a matrix layer. The protective layer PTL can reduce or suppress the formation of the lithium deposited layer LPL. Therefore, the protective layer PTL can reduce or suppress the increase in lithium dendrites and battery volume caused by the formation of the lithium deposited layer LPL.

[0056] Electrolyte layer ETL Return to reference Figure 1 The electrolyte layer (ETL) according to some example embodiments of this disclosure may include at least one of liquid electrolyte, solid electrolyte, gel electrolyte, and combinations thereof.

[0057] In an example embodiment, the electrolyte layer (ETL) can be a liquid electrolyte layer. The liquid electrolyte layer can include an organic electrolyte solution. The organic electrolyte solution can include an organic solvent and a lithium salt. Any suitable material can be selected without limitation, provided that the material is generally included as an organic solvent in the relevant art. For example, the organic solvent can include at least one of the following: propylene carbonate, ethylene carbonate, fluoroethylene carbonate, butyl carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl isopropyl carbonate, dipropyl carbonate, dibutyl carbonate, benzyl nitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, dioxane, 4-methyldioxane, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, 1,2-dimethoxyethane, sulfolane, dichloroethane, chlorobenzene, nitrobenzene, diethylene glycol, dimethyl ether, and mixtures thereof.

[0058] Similarly, any suitable material can be selected without restrictions, as long as it is commonly used as a lithium salt in the relevant field. For example, lithium salts can include LiSCN, LiN(CN)2, Li(CF3SO2)3C, Li(FSO2)2N (LiFSI), LiC4F9SO3, LiN(SO2CF2CF3)2, LiPF3(C2F5)3, LiCl, LiF, LiBr, LiI, LiB(C2O4)2, LiPF6, LiPF5(CF3), LiPF5(C2F5), LiPF5(C3F7), LiPF4(CF3)2, LiPF4(CF3)(C2F5), LiPF3(CF3)3, and LiPF3. At least one of the following: (CF2CF3)3, LiPF4(C2O4)2, LiBF4, LiBF3(C2F5), lithium bis(oxalate)borate (LiBOB), lithium oxaloyl difluoroborate (LiODFB), lithium difluoro(oxalate)borate (LiDFOB), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, LiN(SO2CF3)2), lithium bis(fluorosulfonyl)imide (LiFSI, LiN(SO2F)2, LiN(SO2C2F5)2, LiCF3SO3, LiAsF6, LiSbF6, LiClO4, and any combination thereof.

[0059] For example, the concentration of lithium salt can be in the range of about 0.1 M to about 5.0 M.

[0060] In an example embodiment, the electrolyte layer (ETL) may be or include a solid electrolyte layer. The solid electrolyte layer may include a solid polymer electrolyte. The solid polymer electrolyte may include a mixture of lithium salt and polymer or a polymer having ion-conducting functional groups. The solid polymer electrolyte may be in a solid state at about 1 atm and about 25°C. The solid polymer electrolyte may substantially not contain liquid. The polymer in a solid polymer electrolyte may include at least one of the following: polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), 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), poly(methyl methacrylate) (PMMA), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), polyethylene dioxythiophene (PEDOT), polypyrrole (PPY), polyaniline, polyacetylene, Nafion TM Aquivion TM Flemion TM Gore TM Aciplex TM Morgane TM ADP, sulfonated poly(ether ether ketone) (SPEEK), sulfonated poly(aryl ether ketone sulfone) (SPAEKKS), sulfonated poly(aryl ether ketone) (SPAEK), poly[bis(benzimidazolidinebenzisoquinolinone)] (SPBIBI), poly(styrene sulfonate) (PSS), lithium 9,10-diphenylanthracene-2-sulfonate (DPASLi) + (and combinations thereof). The polymers in solid polymer electrolytes are not limited to these, and any suitable material can be selected without restriction, provided that the material is commonly used in solid polymer electrolytes in the relevant field.

[0061] The lithium salts in solid polymer electrolytes can be selected from those discussed above.

[0062] The polymer in a solid polymer electrolyte may include repeating units, the number of which is equal to or greater than about 10, about 20, about 50, or about 100. For example, the weight-average molecular weight of the polymer in a solid polymer electrolyte may be equal to or greater than about 1,000 Daltons, about 10,000 Daltons, about 100,000 Daltons, or about 1,000,000 Daltons.

[0063] In an example embodiment, the electrolyte layer ETL may be or include a gel-polymer electrolyte (see [link to example embodiment]). Figure 3 Gel-polymer electrolytes (GPEs) can be in a gel state or a semi-solid state. Gel-polymer electrolytes (GPEs) can include a liquid electrolyte and a polymer or an organic solvent and a polymer with ion-conducting functional groups. Gel-polymer electrolytes (GPEs) can be in a gel state or a semi-solid state at about 1 atm and about 25°C.

[0064] For example, a gel-polymer electrolyte (GPE) can have a gel state that does not contain liquid. The liquid electrolyte included in the gel-polymer electrolyte (GPE) can be a mixture of lithium salt and organic solvent, a mixture of ionic liquid and organic solvent, or a mixture of ionic liquid, lithium salt and organic solvent.

[0065] The polymer in the gel-polymer electrolyte (GPE) can be or includes at least one of the polymers discussed above regarding solid polymer electrolytes. The organic solvent in the gel-polymer electrolyte (GPE) can be or includes at least one of the organic solvents discussed above regarding liquid electrolyte layers. The lithium salt in the gel-polymer electrolyte (GPE) can be or includes at least one of the lithium salts discussed above regarding liquid electrolyte layers.

[0066] Ionic liquids in gel-polymer electrolytes (GPEs) can refer to salts that are liquid at room temperature or molten at room temperature, consisting solely of ions having a melting point equal to or below room temperature, or including ions having a melting point equal to or below room temperature. Ionic liquids may include at least one cation (such as at least one of ammonium cations, pyrrolidine cations, pyridine cations, pyrimidine cations, imidazole cations, piperidine cations, pyrazole cations, oxazole cations, pyridazine cations, sulfone cations, and triazole cations) and at least one anion (such as 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 - (at least one of them).

[0067] In an example embodiment, a solid polymer electrolyte can be impregnated into a liquid electrolyte to form a gel-polymer electrolyte (GPE).

[0068] In an example embodiment, the gel-polymer electrolyte GPE may also include inorganic particles.

[0069] In an example embodiment, the polymer in the gel-polymer electrolyte (GPE) may include repeating units, the number of which is equal to or greater than about 10, about 20, about 50, or about 100. For example, the weight-average molecular weight of the polymer in the GPE may be equal to or greater than about 500 Daltons, about 1,000 Daltons, about 10,000 Daltons, about 100,000 Daltons, or about 1,000,000 Daltons.

[0070] In example embodiments, the polymer in the gel-polymer electrolyte GPE may include a crosslinked polymer (see...). Figure 4 (CLP). Figure 4 This is a simplified conceptual diagram illustrating a crosslinked polymer structure according to some example embodiments of the present disclosure. (Refer to...) Figure 4 The crosslinked polymer (CLP) may include a main chain M and multiple side chains S extending from the main chain M. For example, the multiple side chains S may include side chain S1 extending from the main chain M and side chain S2 extending from side chain S1. In addition, the main chain M and the multiple side chains S of the crosslinked polymer CLP may each include a terminal E that terminates the crosslinking or polymerization reaction.

[0071] Crosslinked polymers (CLPs) can be formed through a crosslinking reaction of multifunctional polymerizable monomers or crosslinking agents. For example, a crosslinked polymer (CLP) may include repeating units derived from a crosslinking agent. The crosslinking agent may be or may include materials that are electrochemically stable under operating conditions (e.g., at a voltage of about 4.3 V or higher) when using a positive electrode active material in which nickel is present in an amount equal to or greater than about 90 mol%.

[0072] In example embodiments, the crosslinking agent may include functional groups capable of undergoing a crosslinking reaction. For example, the crosslinking agent may include two or more double bond functional groups, such as (meth)acrylate groups.

[0073] In example embodiments, the crosslinking agent may include at least one of pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate (TMPTMA), propoxylated (3)trimethylolpropane triacrylate (PO(3)TMPTA), propoxylated (6)trimethylolpropane triacrylate (PO(6)TMPTA), ethoxylated trimethylolpropane triacrylate, di(trimethylolpropane)tetraacrylate, pentaerythritol triacrylate (PETA), propoxylated glycerol triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate (THEICTA), and dipentaerythritol pentaacrylate (DPEPA).

[0074] The crosslinking agent can have a weight-average molecular weight in the range of about 200 to about 2,000, for example, about 200 to about 1,000 or about 200 to about 500. When the weight-average molecular weight is less than about 200, the crosslinking point density in the molecular structure of the crosslinked polymer may be quite high and may hinder the free movement of lithium ions, and when the weight-average molecular weight is greater than about 200, the crosslinking point density in the molecular structure of the crosslinked polymer may be quite low and may reduce the electrolyte blocking ability.

[0075] Crosslinked polymers (CLPs) may also include repeating units derived from ionic monomers. Ionic monomers may include at least one double bond functional group and an ionic functional group.

[0076] The double bond functional groups of an ionic monomer may include allyl, acryloyl, vinyl, or any combination thereof. For example, an ionic monomer may include acryloyl, vinyl, or any combination thereof. The ionic functional groups of an ionic monomer may include cationic, anionic, or combinations thereof. For example, when an ionic monomer includes a cationic functional group, the ionic monomer may be or include a cationic monomer. For example, when an ionic monomer includes an anionic functional group, the ionic monomer may be or include an anionic monomer. For example, when an ionic monomer includes both cationic and anionic functional groups, the ionic monomer may be or include an amphoteric ionic monomer.

[0077] In example embodiments, the polymer in the gel-polymer electrolyte GPE may also include linear polymers. Linear polymers may include at least one of polyethylene (PE), styrene-butadiene rubber (SBR), nylon, carboxymethyl cellulose (CMC), polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene (PVDF-HFP), poly(styrene-b-polyethylene 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), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), polyethylene dioxythiophene (PEDOT), polypyrrole (PPY), polyaniline, polyacetylene, and combinations thereof.

[0078] In example embodiments, the linear polymer may be present in an amount equal to or less than about 20 wt% relative to 100 wt% of the polymer in the gel-polymer electrolyte GPE. For example, the amount of linear polymer may range from about 1 wt% to about 20 wt%, from about 5 wt% to about 20 wt%, from about 10 wt% to about 20 wt%, or from about 10 wt% to about 15 wt%. When the amount of linear polymer falls within the above range, the gel-polymer electrolyte GPE may have improved ionic conductivity while maintaining mechanical stability. When the amount of linear polymer exceeds the above range, the gel-polymer electrolyte GPE may have poor mechanical stability.

[0079] In an example embodiment, the polymer in the gel-polymer electrolyte (GPE) may be present in an amount ranging from about 1 wt% to about 10 wt%, about 2 wt% to about 8 wt%, or about 3 wt% to about 7 wt%, relative to the total 100 wt% of the electrolyte layer (ETL). The liquid electrolyte may be present in an amount ranging from about 90 wt% to about 99 wt%, about 92 wt% to about 98 wt%, or about 93 wt% to about 97 wt%, relative to the total 100 wt% of the electrolyte layer (ETL).

[0080] In another example embodiment, the polymer in the gel-polymer electrolyte (GPE) may be present in an amount equal to or less than about 5 wt% relative to the total 100 wt% of the electrolyte layer ETL. For example, the total amount of polymer may range from about 0.1 wt% to about 5 wt%, from about 0.5 wt% to about 5 wt%, from about 1 wt% to about 5 wt%, or from about 1 wt% to about 3 wt%. The liquid electrolyte may be present in an amount equal to or greater than about 95 wt% relative to the total 100 wt% of the electrolyte layer ETL. For example, the amount of liquid electrolyte may range from about 95 wt% to about 99.9 wt%, from about 95 wt% to about 99.5 wt%, from about 95 wt% to about 99 wt%, or from about 95 wt% to about 97 wt%.

[0081] In another example embodiment, the polymer in the gel-polymer electrolyte (GPE) may be present in an amount equal to or greater than about 60 wt% relative to the total 100 wt% of the electrolyte layer ETL. For example, the total amount of polymer may range from about 60 wt% to about 90 wt%, from about 60 wt% to about 80 wt%, from about 65 wt% to about 80 wt%, or from about 70 wt% to about 80 wt%. The liquid electrolyte may be present in an amount equal to or less than about 40 wt% relative to the total 100 wt% of the electrolyte layer ETL. For example, the amount of liquid electrolyte may range from about 10 wt% to about 40 wt%, from about 20 wt% to about 40 wt%, from about 20 wt% to about 35 wt%, or from about 20 wt% to about 30 wt%.

[0082] In an example embodiment, the composite separator layer (CSP) and the protective layer (PTL) can be impregnated within the electrolyte layer (ETL). For instance, the first pore (POR1) of the separator (SEP) can be filled with a gel-polymer electrolyte (GPE) (see...). Figure 2 The second pore of the protective layer PTL, POR2, can be filled with a gel-polymer electrolyte GPE (see...). Figure 2 ).

[0083] Composite isolation layer CSP Reference Figure 1 and Figure 2 The composite separator layer (CSP) can be disposed between the positive electrode (PEL) and the negative electrode (NEL). The composite separator layer (CSP) may include a separator (SEP) and a lithium-repellent metal layer (PML) on the first surface (SUF1) of the separator (SEP).

[0084] like Figure 2 As shown, the separator SEP may have a first surface SUF1 and a second surface SUF2. The first surface SUF1 and the second surface SUF2 may face away from each other. The first surface SUF1 of the separator SEP may face the negative electrode NEL. The second surface SUF2 of the separator SEP may face the positive electrode PEL.

[0085] The diaphragm SEP may include one or more of polyethylene, polypropylene and polyvinylidene fluoride, and may have multilayer diaphragms, such as polyethylene / polypropylene double diaphragm, polyethylene / polypropylene / polyethylene triple diaphragm and polypropylene / polyethylene / polypropylene triple diaphragm.

[0086] The diaphragm SEP may include a porous substrate. The porous substrate may be or include a polymer layer, which includes polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, and Teflon. TM It may be one of (polytetrafluoroethylene), or a copolymer or mixture of two or more of the above materials.

[0087] The separator SEP can have a porosity in the range of about 40% to about 80%. For example, the porosity of the separator SEP can be in the range of about 40% to about 70% or about 50% to about 70%. The separator SEP can have a thickness TK1 in the range of about 2 μm to about 40 μm. For example, the thickness TK1 of the separator SEP can be in the range of about 2 μm to about 40 μm, about 3 μm to about 30 μm, about 3 μm to about 15 μm, about 3 μm to about 12 μm, about 5 μm to about 12 μm, or about 5 μm to about 10 μm. When the thickness TK1 of the separator SEP is greater than the above range, the resistance may increase due to the increase in the migration path of lithium ions. When the thickness TK1 of the separator SEP is less than the above range, a short circuit may occur due to the lack of mechanical properties or weak mechanical properties.

[0088] The lithium-repellent metal layer PML can be selectively disposed on the first surface SUF1 of the separator SEP instead of the second surface SUF2. The lithium-repellent metal layer PML can be in contact with the protective layer PTL. The lithium-repellent metal layer PML can be separated from the positive electrode PEL by the separator SEP.

[0089] A lithium-repellent metal layer (PML) may include a lithium-repellent metal. The lithium-repellent metal can be a metal with a low affinity for lithium. Lithium may hardly adsorb onto the surface of the lithium-repellent metal. High voltage may be advantageous when plating (or electroplating) lithium onto a lithium-repellent metal. The lithium-repellent metal layer (PML) may include at least one of platinum (Pt), aluminum (Al), nickel (Ni), and iron (Fe). For example, the lithium-repellent metal layer (PML) may include platinum (Pt).

[0090] The lithium-repellent metal layer PML can have a thickness TK2 that is smaller than the thickness TK1 of the separator SEP. For example, the thickness TK2 of the lithium-repellent metal layer PML can be in the range of about 10 nm to about 100 nm, but this disclosure is not limited thereto.

[0091] In an example embodiment, the lithium-repellent metal layer PML can be formed by performing a sputtering process on the first surface SUF1 of the separator SEP. In another embodiment, the lithium-repellent metal layer PML can be formed by performing an electroplating process on the first surface SUF1 of the separator SEP.

[0092] A lithium-repellent metal layer (PML) can be configured to guide lithium ions to migrate in the horizontal direction D1 rather than the vertical direction D3. The PML can restrict the deposition site of lithium to reduce or suppress dendrite formation.

[0093] Positive electrode PEL Refer again Figure 1 The positive electrode PEL of a lithium metal battery may include a positive electrode current collector COL2 and a positive electrode active material layer PAL formed on the positive electrode current collector COL2. The positive electrode active material layer PAL may include a positive electrode active material and may also include a binder and / or a conductive material. For example, the positive electrode active material layer PAL may also include additives that can be configured as a sacrificial positive electrode.

[0094] Relative to 100 wt% of the positive electrode active material layer PAL, the positive electrode active material in the positive electrode active material layer PAL may be present in an amount ranging from about 90 wt% to about 99 wt%. Relative to 100 wt% of the positive electrode active material layer PAL, the binder and conductive material may each be present in an amount ranging from about 0.5 wt% to about 5 wt%.

[0095] The binder can be configured to improve the adhesion between the positive electrode active material particles and the adhesion between the positive electrode active material and the positive electrode current collector COL2. The binder may include, for example, at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, and nylon, but this disclosure is not limited thereto.

[0096] Conductive materials may be included to provide conductivity to the electrodes. Any electrically conductive material may be included as a conductive material, unless the conductive material causes a chemical change. Conductive materials may include, for example: carbon-based materials, such as at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metal powders or metal fibers including one or more of copper, nickel, aluminum, and silver; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0097] The positive electrode current collector COL2 can provide a reference surface on which the positive electrode active material layer PAL is disposed. For example, the positive electrode current collector COL2 may include at least one 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), and alloys thereof. The positive electrode current collector COL2 may have a plate shape or a foil shape. In another exemplary embodiment of this disclosure, the positive electrode current collector COL2 may be omitted. The positive electrode current collector COL2 may have a thickness ranging from, for example, about 1 μm to about 100 μm, about 1 μm to about 50 μm, about 5 μm to about 25 μm, or about 10 μm to about 20 μm. In an exemplary embodiment, the positive electrode current collector COL2 may include aluminum (Al), but this disclosure is not limited thereto.

[0098] The positive electrode active material in the positive electrode active material layer (PAL) may include compounds capable of reversibly inserting and deintercalating lithium (e.g., lithiation intercalation compounds). For example, the positive electrode active material may include at least one composite oxide, which includes lithium and a metal, wherein the metal is or includes at least one of cobalt, manganese, nickel, and combinations thereof.

[0099] The composite oxide may include lithium transition metal composite oxides, such as lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free lithium nickel manganese oxides, and combinations thereof, at least one of these.

[0100] For example, the positive electrode active material may include a compound represented by one of the following chemical formulas: Li a A 1- b X b O 2-c D c (Where, 0.90≤a≤1.8, 0≤b≤0.5 and 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (Where, 0.90≤a≤1.8, 0≤b≤0.5 and 0≤c≤0.05); Lia Ni 1-b-c Co b X c O 2-α D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5 and 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5 and 0<α<2); Li a Ni b Co c L 1 d G e O2 (where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5 and 0≤e≤0.1); Li a NiG b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a CoG b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-b G b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn2G b O4 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (where 0.90 ≤ a ≤ 1.8 and 0 ≤ g ≤ 0.5); Li (3-f) Fe2(PO4)3 (where 0≤f≤2); Li a FePO4 (where 0.90≤a≤1.8).

[0101] In the above chemical formulas, A can be or include at least one of Ni, Co, Mn, and combinations thereof; X can be or include at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, and combinations thereof; D can be or include at least one of O, F, S, P, and combinations thereof; G can be or include at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, and combinations thereof; and L 1 It may be or include at least one of Mn, Al and combinations thereof.

[0102] A coating layer may be additionally added to the surface of the compounds discussed above. The coating layer may include, for example, at least one of the following: oxides, hydroxides, hydroxyoxides, oxycarbonates, or hydroxycarbonates of the coating element. The coating layer may be amorphous or crystalline. The coating element included in the coating layer may be or include at least one of Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, and Zr. The method for forming the coating layer may be any method that does not adversely affect the physical properties of the positive electrode active material. The method for forming the coating layer may include, for example, spraying or dipping.

[0103] For example, the positive electrode active material can be or includes a high-nickel positive electrode active material, wherein the nickel content of the high-nickel positive electrode active material is equal to or greater than about 80 mol%, equal to or greater than about 85 mol%, equal to or greater than about 90 mol%, equal to or greater than about 91 mol%, or equal to or greater than about 94 mol% and equal to or less than about 99 mol%, relative to 100 mol% of lithium-free metal in the lithium transition metal complex oxide. High-nickel positive electrode active materials can achieve high capacity and therefore can be used in high-capacity and high-density lithium metal batteries.

[0104] According to exemplary embodiments of this disclosure, the high-nickel positive electrode active material can be derived from Li a Ni 1-b-c Co b X c O 2-d (where 0.90≤a≤1.8, 0≤b≤0.2, 0≤c≤0.2, 0.8≤1-bc≤0.99 and 0≤d≤0.2) represents this. X can be or include at least one of Al, Mn, and combinations thereof. High-nickel positive electrode active materials can have a capacitance equal to or greater than about 5.0 mAh / cm³. 2 High capacity.

[0105] Return to reference Figure 2 The positive electrode active material layer (PAL) does not have to be flat; it can have an uneven surface. For example, the surface of the positive electrode active material layer (PAL) may include multiple recessed regions (DTR).

[0106] In an example embodiment, the gel-polymer electrolyte (GPE) of the electrolyte layer ETL can fill all or substantially all of the recessed regions DTR of the positive electrode active material layer PAL. For example, the gel-polymer electrolyte GPE may include raised PRPs that substantially fill the recessed regions DTR accordingly. The recessed regions DTR can give the surface of the positive electrode active material layer PAL a relatively large specific surface area. Because the gel-polymer electrolyte GPE includes raised PRPs corresponding to the recessed regions DTR, the contact area between the gel-polymer electrolyte GPE and the positive electrode active material layer PAL can be increased.

[0107] Reference Figure 3 When the lithium metal battery is charged, a lithium deposition layer (LPL) can be formed by lithium ions. When the lithium metal battery is charged, a lithium-plated LPP can be formed by lithium ions in the protective layer (PTL). In an example embodiment, the gel-polymer electrolyte (GPE) filling the second pore (POR2) ​​allows for incomplete formation of the lithium-plated LPP in the second pore (POR2), but this disclosure is not limited thereto.

[0108] Because the lithium-phobic metal layer (PML) has no affinity for lithium, lithium ions can disperse and move horizontally rather than vertically. The protective layer (PTL) can have a three-dimensional nanofiber structure and an affinity for lithium, thus facilitating lithium ion migration and electrodeposition.

[0109] The lithium-repellent metal layer (PML) and the protective layer (PTL) can be correlated to produce a synergistic effect, thus allowing for the formation of a substantially uniform lithium deposition layer (LPL) without dendrite formation. As a result, the lithium metal battery according to the examples of this disclosure can improve lifespan and reduce or suppress side reactions caused by lithium metal.

[0110] According to some exemplary embodiments of this disclosure, the positive electrode active material layer (PAL) can have a high capacity. For example, the positive electrode active material layer (PAL) can have a capacity equal to or greater than about 5.0 mAh / cm³. 2 The capacity of the positive electrode active material layer PAL can be approximately 5.0 mAh / cm³. 2 Approximately 10.0 mAh / cm 2 The capacity is within a certain range. In an example embodiment, the positive electrode active material layer (PAL) may include a high-nickel positive electrode active material to achieve high capacity. In an example embodiment, the positive electrode active material layer (PAL) may have a thick layered shape to achieve high capacity.

[0111] When a high-capacity positive electrode is included, lithium metal batteries with a negative electrode-less structure may experience drawbacks such as excessive dendrite growth on the negative electrode. In lithium metal batteries according to some example embodiments of this disclosure, as discussed above, the combination of a lithium-repellent metal layer (PML) and a protective layer (PTL) can reduce or suppress dendrite formation and side reactions caused by lithium metal. Therefore, examples of this disclosure may include lithium metal batteries with a high-capacity positive electrode. Lithium metal batteries according to examples of this disclosure can have high capacity and desired or improved lifetime characteristics.

[0112] Lithium metal batteries Reference Figure 5 A lithium metal battery (LBT) according to an example embodiment of the present disclosure may include a positive electrode (PEL), a negative electrode (NEL), and a composite separator (CSP).

[0113] The positive electrode (PEL), negative electrode (NEL), and composite separator (CSP) can be wound or stacked to form a battery structure (BTS). The battery structure (BTS) can be housed within a battery casing (CAS). The battery casing (CAS) can be filled with an electrolyte solution to form an electrolyte layer. The battery casing (CAS) can be sealed using a cover assembly (CAB) to manufacture a lithium metal battery (LBT). The battery casing (CAS) can have a cylindrical shape, but this disclosure is not limited thereto. For example, the battery casing (CAS) can have a prismatic shape, a pouch shape, etc.

[0114] Reference Figure 6 A lithium metal battery (LBT) according to an example embodiment of the present disclosure may include a positive electrode (PEL), a negative electrode (NEL), and a composite separator (CSP). The composite separator (CSP) may be disposed between the positive electrode (PEL) and the negative electrode (NEL), and the positive electrode (PEL), the negative electrode (NEL), and the composite separator (CSP) may be wound or stacked to form a battery structure (BTS).

[0115] The battery structure BTS can be housed within a battery casing CAS. It may include electrode terminals (ELTs), which form electrical paths for guiding current generated within the battery structure BTS outwards. The battery casing CAS may be infused with an electrolyte solution to form an electrolyte layer. The battery casing CAS can be sealed to manufacture a lithium metal battery (LBT). The battery casing CAS may have a prismatic shape, but this disclosure is not limited thereto. For example, the battery casing CAS may have a cylindrical shape, a pouch shape, etc.

[0116] Reference Figure 7 A lithium metal battery (LBT) according to an example embodiment of the present disclosure may include a positive electrode (PEL), a negative electrode (NEL), and a composite separator (CSP). The composite separator (CSP) may be disposed between the positive electrode (PEL) and the negative electrode (NEL) to form a battery structure (BTS).

[0117] The battery structure BTS can be stacked in a dual-cell configuration and housed within a battery casing CAS. It may include electrode terminals (ELTs), which form electrical paths for guiding current generated within the battery structure BTS outwards. The battery casing CAS may be infused with an electrolyte solution to form an electrolyte layer. The battery casing CAS can be sealed to manufacture a lithium metal battery (LBT). The battery casing CAS may have a prismatic shape, but this disclosure is not limited thereto. For example, the battery casing CAS may have a cylindrical shape, a pouch shape, etc.

[0118] pouch-type lithium metal batteries can correspond to... Figures 5 to 7 Each of the lithium metal battery LBTs shown uses a pouch as the battery casing CAS. A pouch-type lithium metal battery may include at least one battery structure BTS. After the battery structures BTS are stacked in a dual-cell configuration, the battery structures BTS can be impregnated in an electrolyte layer, housed in a pouch, and sealed to manufacture a pouch-type lithium metal battery.

[0119] For example, a positive electrode, a negative electrode, and a composite insulating layer can be stacked in an electrode assembly and housed in a bag. The electrode assembly can be wound or folded into an electrode core form and then housed in the bag. The bag can be filled with an electrolyte solution to form an electrolyte layer.

[0120] Because lithium metal batteries exhibit desired or improved lifespan and high rate capability, they can be used in applications such as electric vehicles (EVs). For example, lithium metal batteries can be used in plug-in hybrid electric vehicles (PHEVs). Furthermore, lithium metal batteries can be applied in areas requiring large-scale energy storage. For instance, lithium metal batteries can be included in electric bicycles and power tools.

[0121] Multiple lithium metal batteries can be stacked to form a battery module. Multiple battery modules can constitute a battery pack. Battery packs can be used in any device requiring high capacity and high power output. For example, battery packs can be included in laptops, smartphones, electric vehicles, etc. A battery module can include, for example, multiple batteries and a frame supporting the batteries.

[0122] A battery pack may include, for example, multiple battery modules and busbars connecting the battery modules to each other. The battery modules and / or the battery pack may also include cooling devices. Multiple battery packs may be controlled by a battery management system. The battery management system may include battery controllers connected to the battery packs.

[0123] Manufacturing method Figures 8A to 8E This is a cross-sectional view illustrating a method for manufacturing a lithium metal battery according to some example embodiments of the present disclosure.

[0124] Reference Figure 8AA diaphragm SEP can be prepared. The diaphragm SEP may include a porous substrate. The diaphragm SEP may have a first surface SUF1 and a second surface SUF2 facing each other.

[0125] A lithium-repellent metal layer (PML) can be selectively formed on the first surface SUF1 of the separator SEP. In an example embodiment, forming the lithium-repellent metal layer (PML) may include performing a sputtering process on the first surface SUF1 of the separator SEP. In another example embodiment, forming the lithium-repellent metal layer (PML) may include performing an electroplating process on the first surface SUF1 of the separator SEP.

[0126] The lithium-repellent metal layer (PML) can be formed of or comprise a lithium-repellent metal. For example, the lithium-repellent metal can include at least one of platinum (Pt), aluminum (Al), nickel (Ni), and iron (Fe). Specifically, the lithium-repellent metal can include platinum (Pt).

[0127] The lithium-repellent metal layer (PML) can be formed to be thinner than the separator (SEP). For example, the lithium-repellent metal layer (PML) can be formed to have a thickness in the range of about 10 nm to about 100 nm, but this disclosure is not limited thereto.

[0128] The separator SEP and the lithium-repellent metal layer PML can form a composite separator CSP.

[0129] Reference Figure 8B An electrospinning process can be performed to form a protective layer PTL. Formation of the protective layer PTL may include allowing the needle NDL to discharge a polymer solution onto the substrate. The electrospinning process can be performed until the thickness of the protective layer PTL is in the range of about 1 μm to about 100 μm or about 1 μm to about 50 μm.

[0130] Polymer solutions may include polymers, metal precursor compounds, and solvents. The polymer may be or include the components described above. Figure 2 The precursors of porous carbon structures (CNFs) discussed. For example, porous carbon structures (see...) Figure 2 The CNF (nanofibers) can originate from polymers in a polymer solution. Electrospinning can provide the substrate with polymers in nanofiber form. Electrospinning can then form porous structures from these nanofibers. These porous structures can form the framework for the protective PTL (Polymer Transformer Layer).

[0131] The metal precursor compound may include a lithium-philic metal. For example, the metal precursor compound may include at least one of silver (Ag), gold (Au), copper (Cu), tin (Sn), and bismuth (Bi). The metal precursor compound may include at least one of a metal oxide, a metal nitride, or an organometallic compound (e.g., a metal acetate). The metal precursor compound may have a nanoscale particle shape. Electrospinning can allow the metal precursor compound to adhere substantially uniformly to the porous structure of the protective layer PTL.

[0132] In the example embodiment, after the electrospinning process, an annealing process can be performed on the protective PTL layer. The annealing process can carbonize the porous structure to form... Figure 2 The porous carbon structure CNF. Annealing can be performed by carbonizing the porous structure and reducing the metal precursor compound. Carbothermic or hydrothermal reduction can occur during the annealing process. For example, the annealing process can be carried out in an atmospheric and / or nitrogen atmosphere at temperatures ranging from about 250°C to about 1200°C.

[0133] Annealing can reduce metal precursor compounds to form Figure 2 Lithophilic particles (SNPs) can be distributed substantially uniformly on the surface of porous carbon structure (CNF). The porous carbon structure (CNF) and the lithiophilic particles (SNPs) can form a protective layer (PTL).

[0134] Reference Figure 8C The negative electrode current collector COL1 can be provided with a... Figure 8B The protective layer PTL is manufactured in the process. The negative electrode current collector COL1 may include at least one of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The negative electrode current collector COL1 may have a thickness in the range of about 1 μm to about 20 μm, for example, about 5 μm to about 15 μm or about 7 μm to about 10 μm.

[0135] The negative electrode current collector COL1 can be provided with a... Figure 8A The composite isolation layer (CSP) is manufactured in [the process described]. The composite isolation layer CSP can be stacked on the protective layer PTL. The lithium-repellent metal layer (PML) of the composite isolation layer CSP can directly face the protective layer PTL of the negative electrode NEL.

[0136] The positive electrode PEL can be disposed on the composite isolation layer CSP. The positive electrode PEL may include a positive electrode current collector COL2 and a positive electrode active material layer PAL. The positive electrode current collector COL2 can provide a reference surface on which the positive electrode active material layer PAL is disposed. The positive electrode current collector COL2 may include at least one 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), and alloys thereof. The positive electrode active material layer PAL may include a compound capable of reversibly inserting and deintercalating lithium (e.g., a lithiation intercalation compound). In an example embodiment, the positive electrode active material layer PAL may have a capacity equal to or greater than about 5.0 mAh / cm³. 2 High capacity.

[0137] Reference Figure 8D An electrolyte solution GPC can be provided on the stack of the negative electrode NEL, the composite isolation layer CSP, and the positive electrode PEL. The electrolyte solution GPC can fill the space between the negative electrode NEL and the positive electrode PEL. The composite isolation layer CSP and the protective layer PTL can be impregnated with the electrolyte solution GPC.

[0138] Electrolyte solution GPC can be a precursor for forming an electrolyte layer (ETL), as will be discussed below. Electrolyte solution GPC can include at least one of a liquid electrolyte, a polymer precursor, and a thermal initiator. The polymer precursor can include a crosslinking agent. The crosslinking agent can form a crosslinked polymer through a crosslinking reaction. The polymer precursor can also include linear polymers and ionic monomers.

[0139] The crosslinking agents, ionic monomers, liquid electrolytes, and linear polymers in the electrolyte solution GPC can be the same as or substantially the same as those discussed above in the gel-polymer electrolyte GPE.

[0140] For example, the crosslinking agent may include two or more double bond functional groups, such as (meth)acrylate groups. In example embodiments, the crosslinking agent may include at least one of pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate (TMPTMA), propoxylated (3)trimethylolpropane triacrylate (PO(3)TMPTA), propoxylated (6)trimethylolpropane triacrylate (PO(6)TMPTA), ethoxylated trimethylolpropane triacrylate, di(trimethylolpropane)tetraacrylate, pentaerythritol triacrylate (PETA), propoxylated glycerol triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate (THEICTA), and dipentaerythritol pentaacrylate (DPEPA).

[0141] For example, linear polymers may include at least one of polyethylene (PE), styrene-butadiene rubber (SBR), nylon, carboxymethyl cellulose (CMC), polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene (PVDF-HFP), poly(styrene-b-polyethylene 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), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), polyethylene dioxythiophene (PEDOT), polypyrrole (PPY), polyaniline, and polyacetylene.

[0142] In an example embodiment, providing the electrolyte solution GPC may include: having a bag receive a stack of a negative electrode NEL, a composite insulating layer CSP, and a positive electrode PEL; and filling the bag with the electrolyte solution GPC.

[0143] Reference Figure 8E The HEP (High-Energy Annealing) process can be performed on the stack. The HEP process can form an electrolyte layer (ETL) from an electrolyte solution GPC (Gas Processing Polymerization). For example, crosslinking agents in the electrolyte solution GPC can be polymerized with ionic monomers to form a polymer.

[0144] As shown above (refer to the reference) Figure 2 The electrolyte layer ETL discussed herein can be in direct contact with the positive electrode active material layer PAL. The electrolyte layer ETL can also be in direct contact with the negative electrode current collector COL1. Optionally, the protective layer PTL may prevent the electrolyte layer ETL from directly contacting the negative electrode current collector COL1. The composite separator layer CSP and the protective layer PTL can be impregnated within the electrolyte layer ETL. The electrolyte layer ETL can fill the first pore POR1 of the separator SEP. The electrolyte layer ETL can fill the second pore POR2 of the protective layer PTL.

[0145] Figure 14This is a flowchart illustrating a method for manufacturing a lithium metal battery according to an example embodiment. In the example, method 1400 includes operations 1410 to 1450. Operation 1410 includes preparing a composite separator by forming a lithium-repellent metal layer on a first surface of a separator. Operation 1420 includes preparing a protective layer by performing an electrospinning process using a mixed solution of a polymer and a metal precursor compound. Operation 1430 includes forming a stack by stacking (e.g., sequentially stacking) a negative electrode current collector, a protective layer, a composite separator, and a positive electrode. Operation 1440 includes providing an electrolyte solution to the stack, wherein the composite separator is impregnated in the electrolyte solution. Operation 1450 includes thermally crosslinking the electrolyte solution to form an electrolyte layer. In the example, method 1400 also includes performing an annealing process on the protective layer to carbonize the polymer and reduce the metal precursor compound.

[0146] This disclosure has been described in detail herein with reference to some exemplary embodiments. The following exemplary embodiments are provided for illustrative purposes only and are not to be construed as limiting the scope of this disclosure.

[0147] Example 1 Electrolyte solution: A liquid electrolyte was prepared by dissolving 1.0 M LiPF6 in a non-aqueous organic solvent comprising ethylene carbonate (EC) and diethyl carbonate (DEC) mixed in a 50:50 volume ratio. Trimethylolpropane trimethacrylate (TMPTMA) was added to the liquid electrolyte as a crosslinking agent to prepare an electrolyte solution. TMPTMA was present in an amount of 3 wt% relative to the total weight of the electrolyte solution.

[0148] Positive electrode: Li 1.04 Ni 0.8 Co 0.1 Al 0.1 O2 powder and carbon conductive material (Super-P, commercially available from Timcal) TM The active material, carbon conductive material and binder are mixed uniformly in a weight ratio of 90:5 and polyvinylidene fluoride (PVDF) binder solution is added to prepare a positive electrode active material slurry. In the positive electrode active material slurry, the active material, carbon conductive material and binder are mixed in a weight ratio of 90:5:5.

[0149] A slurry was coated to a thickness of 15 μm onto an aluminum substrate using a doctor blade. The coating was dried under reduced pressure at 120 °C and then rolled to fabricate a positive electrode in sheet form. The capacity of the positive electrode was approximately 5 mAh / cm³. 2 .

[0150] Composite isolation layer: A lithium-repellent metal layer was formed on the first surface of a 5 μm thick polyethylene separator using platinum. The lithium-repellent metal layer was formed by sputtering using a Q150R S, commercially available from Quorum Technologies. The sputtering current was 66 mA, the sputtering time was 120 seconds, and a platinum layer with a thickness of 25 nm was deposited.

[0151] Protective layer: To prepare a polymer solution, 10% polyacrylonitrile (PAN, Sigma-Aldrich) and N,N-dimethylformamide (DMF, DUKSAN reagents) were mixed for 30 minutes using a planetary centrifuge mixer (available commercially from Thiky) as a high-viscosity paste mixer. 0.5 g of silver oxide (NANOSHEL) was then added to the polymer solution, and the mixture was mixed for another 60 minutes.

[0152] A protective layer is prepared by electrospinning a polymer solution onto a substrate under the following conditions.

[0153] Voltage: 18kV, spinning distance: 15cm, spinning solution flow rate: 0.5mL / h, spinning time: 1 hour 30 minutes The protective layer is then annealed. The annealing process is performed in the following order.

[0154] i) Heat to 270°C at a rate of 10°C per minute. ii) Stabilize the process in air for 1 hour at a rate of 0.5°C per minute within a temperature range of 270°C to 300°C. iii) Heating to 1,000°C at a rate of 10°C per minute under nitrogen atmosphere. iv) Maintain at 1,000°C for 1 hour under nitrogen atmosphere. Lithium metal batteries: A composite insulating layer and a protective layer are disposed between the positive electrode and a 10 μm thick copper foil (negative electrode current collector). The stack is received in a bag and then injected with an electrolyte solution. The bag is vacuum-sealed to impregnate the composite insulating layer and the protective layer with the electrolyte solution. A thermosetting process is then performed at 70°C for 2 hours to fabricate an electrolyte layer comprising a gel-polymer electrolyte.

[0155] Example 2 The positive electrode is manufactured to have approximately 6 mAh / cm². 2 The capacity. Apart from this capacity difference, the lithium metal battery was manufactured using the same method as in Example 1.

[0156] Comparative Example 1 A lithium metal battery is manufactured by omitting the formation of the lithium-repellent metal layer and protective layer from Example 1.

[0157] Comparative Example 2 A lithium metal battery is manufactured by omitting the formation of the lithium-repellent metal layer and protective layer from Example 2.

[0158] Table 1 shows the features of Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0159] Table 1:

[0160] Evaluation Example 1: Image of the diaphragm Figure 9 Photographs of the diaphragm and platinum layer (or composite separator) in Example 1 and the diaphragm in Comparative Example 1 are shown. (Refer to...) Figure 9 It can be determined that in the composite isolation layer of Example 1, the platinum layer is formed substantially uniformly on one surface of the membrane.

[0161] Evaluation Example 2: Analysis of the Surface of the Protective Layer The surface of the protective layer in Example 1 was analyzed using an AIS 2000C (scanning electron microscope) available from SERON Corporation. The results are as follows: Figure 10 As shown in the image. (Refer to...) Figure 10 It can be determined that in the protective layer of Example 1, the nanoparticles are advantageously attached to the surface of the carbon nanofibers.

[0162] Evaluation Example 3: Lifespan of High-Capacity Lithium Metal Batteries The lifetime characteristics of Examples 1, 2, Comparative Example 1, and Comparative Example 2 were evaluated under the following conditions.

[0163] The lithium metal battery was charged at 25°C with a constant current at a rate of 0.1C until the voltage reached 4.25V (vs. Li), then the current was cut off at a rate of 0.05C while maintaining the voltage at 4.25V in constant voltage mode. The lithium metal battery was then discharged with a constant current at a rate of approximately 0.1C until the voltage reached 2.5V (vs. Li) (formation cycle).

[0164] The lithium metal battery was charged at 25°C with a constant current at a rate of 0.3C until the voltage reached 4.25V (vs. Li). The current was then cut off at a rate of 0.01C while maintaining the voltage at 4.25V in constant voltage mode. The lithium metal battery was then discharged at a constant current at a rate of 0.3C until the voltage reached 2.5V (vs. Li) (cycle 1). This cycle was repeated under the same conditions.

[0165] A 10-minute rest period was provided after each charge-discharge cycle in all charge-discharge cycles. Positive electrode capacity and coulombic efficiency were measured over 100 cycles.

[0166] Figure 11 The positive electrode capacity and coulombic efficiency of Example 1 and Comparative Example 1 during 70 cycles are shown.

[0167] Figure 12 The positive electrode capacity and coulombic efficiency of Example 2 and Comparative Example 2 during 60 cycles are shown.

[0168] Figure 13 Cross-sectional images of the negative electrodes of Example 1 and Comparative Example 1 in their charged state after cycling are shown.

[0169] Reference Figure 11 It can be observed that the lithium metal battery in Comparative Example 1 exhibits a sharp decrease in positive electrode capacity after 40 cycles. It can be confirmed that the lithium metal battery in Comparative Example 1 exhibits a sharp decrease in coulombic efficiency after 40 cycles. In the lithium metal battery of Comparative Example 1, repeated cycling may lead to excessive dendrite formation, resulting in a rapid reduction in battery life.

[0170] In contrast, it can be observed that the lithium metal battery of Example 1 exhibits almost no decrease in positive electrode capacity and stable coulombic efficiency during 70 cycles. It can be confirmed that the lithium metal battery of Example 1 has the desired or improved lifespan due to the reduction or suppression of dendrite formation.

[0171] Reference Figure 12 It can be observed that the lithium metal battery in Comparative Example 2 exhibits a sharp decrease in positive electrode capacity after 20 cycles. It can also be found that the lithium metal battery in Comparative Example 2 shows a sharp decrease in coulombic efficiency after 20 cycles. In the lithium metal battery of Comparative Example 2, repeated cycling may lead to excessive dendrite formation, resulting in a rapid reduction in battery life. It can be determined that, compared to... Figure 11 Compared to Comparative Example 1, the increase in positive electrode capacity leads to a rapid decrease in battery life.

[0172] In contrast, it can be observed that the lithium metal battery of Example 2 exhibits stability of the positive electrode capacity during 40 cycles and stability of the coulombic efficiency during 60 cycles. It can be confirmed that the lithium metal battery of Example 2 has the desired or improved lifetime even at high capacities due to the reduction or suppression of dendrite formation.

[0173] Reference Figure 13It can be observed that excessive dendrite formation occurs on the negative electrode of the lithium metal battery in Comparative Example 1. In contrast, it can be determined that almost no dendrite formation occurs on the negative electrode of the lithium metal battery in Example 1, even after cycling.

[0174] In the lithium metal battery of the examples according to this disclosure, an expansion buffer layer (e.g., a lithium-repellent metal layer and a protective layer) can be used to effectively accommodate variations in the thickness of the lithium deposited layer. Despite variations in the thickness of the lithium deposited layer, the lithium metal battery of the examples according to this disclosure can also stably maintain the interface between the electrolyte layer and the negative electrode. Therefore, the examples of this disclosure can reduce or suppress the formation of lithium dendrites and improve battery life characteristics.

Claims

1. A lithium metal battery, the lithium metal battery comprising: Negative electrode current collector; A protective layer is provided on the negative electrode current collector, wherein the protective layer comprises a porous carbon structure and a plurality of lithium-loving particles dispersed in the porous carbon structure; A composite isolation layer on the protective layer, wherein the composite isolation layer includes a membrane and a lithium-repellent metal layer on a first surface of the membrane, wherein the lithium-repellent metal layer faces the protective layer; and The positive electrode is located on the composite insulating layer. The positive electrode includes a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector. The positive electrode active material layer comprises Li a Ni 1-b-c Co b X c O 2-d The positive electrode active material is represented by the following formula: 0.90≤a≤1.8, 0≤b≤0.2, 0≤c≤0.2, 0.8≤1-bc≤0.99 and 0≤d≤0.

2. Wherein, X includes at least one of Al and Mn.

2. The lithium metal battery according to claim 1, wherein, The porosity of the porous carbon structure is in the range of 40% to 80%.

3. The lithium metal battery according to claim 1, wherein, The lithiophilic particles include at least one of silver, gold, copper, tin, and bismuth.

4. The lithium metal battery according to claim 1, wherein, The thickness of the lithium-repellent metal layer is in the range of 10 nm to 100 nm.

5. The lithium metal battery according to claim 1, wherein, The lithium-repellent metal layer includes at least one of platinum, aluminum, nickel, and iron.

6. The lithium metal battery according to claim 1, wherein: The lithium-repellent metal layer is configured to disperse lithium ions, and The protective layer is configured to uniformly coat the lithium ions.

7. The lithium metal battery according to claim 1, wherein the lithium metal battery further comprises a lithium deposition layer between the negative electrode current collector and the protective layer.

8. The lithium metal battery according to claim 1, wherein, The protective layer also includes lithium plated in the porous carbon structure.

9. The lithium metal battery according to claim 1, wherein, The positive electrode active material layer has a capacity of 5.0 mAh / cm³. 2 Up to 10.0mAh / cm 2 The capacity within the range.

10. The lithium metal battery according to claim 1, further comprising an electrolyte layer between the negative electrode current collector and the positive electrode active material layer. in, The electrolyte layer comprises a gel-polymer electrolyte.

11. The lithium metal battery according to claim 10, wherein: The gel-polymer electrolyte fills the first pore of the membrane, and The gel-polymer electrolyte fills the second pore of the porous carbon structure.

12. A lithium metal battery, the lithium metal battery comprising: negative electrode; Positive electrode; An electrolyte layer is located between the negative electrode and the positive electrode; as well as A composite isolation layer is impregnated in the electrolyte layer. The negative electrode includes a negative electrode current collector and a protective layer on the negative electrode current collector. The composite isolation layer includes a membrane and a lithium-repellent metal layer on the first surface of the membrane. The lithium-repellent metal layer is positioned opposite the protective layer. The protective layer comprises a porous carbon structure and multiple lithium-loving particles dispersed within the porous carbon structure. The electrolyte layer includes a gel-polymer electrolyte.

13. The lithium metal battery according to claim 12, wherein, The positive electrode active material layer of the positive electrode has a capacity of 5.0 mAh / cm³. 2 Up to 10.0mAh / cm 2 The capacity within the range.

14. The lithium metal battery according to claim 12, wherein, The porosity of the porous carbon structure is in the range of 40% to 80%.

15. The lithium metal battery according to claim 12, wherein, The lithiophilic particles include at least one of silver, gold, copper, tin, and bismuth.

16. The lithium metal battery according to claim 12, wherein, The thickness of the lithium-repellent metal layer is in the range of 10 nm to 100 nm.

17. The lithium metal battery of claim 12, wherein the lithium-repellent metal layer comprises at least one selected from platinum, aluminum, nickel, and iron.

18. The lithium metal battery according to claim 12, wherein: The gel-polymer electrolyte fills the first pore of the membrane, and The gel-polymer electrolyte fills the second pore of the porous carbon structure.

19. A method for manufacturing a lithium metal battery, the method comprising the following steps: A composite separator layer is prepared by forming a lithium-repellent metal layer on the first surface of the separator. The protective layer is prepared by performing an electrospinning process using a mixed solution of polymer and metal precursor compounds. A stack is formed by stacking a negative electrode current collector, the protective layer, the composite isolation layer, and a positive electrode; An electrolyte solution is provided to the stack, wherein the composite isolation layer is impregnated in the electrolyte solution; as well as The electrolyte solution is thermally cross-linked to form an electrolyte layer.

20. The method of claim 19, further comprising performing an annealing process on the protective layer to carbonize the polymer and reduce the metal precursor compound.

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