Additive for lithium rechargeable battery and lithium rechargeable battery including same

Abstract

The present invention relates to an additive for a lithium rechargeable battery and a lithium rechargeable battery including same. The additive is represented by chemical formula 1. (The definition of each substituent is in accordance with the specification.)

Description

Additive for lithium secondary battery and lithium secondary battery containing same

[0001] The present invention relates to an additive for a lithium secondary battery and a lithium secondary battery including the same.

[0002]

[0003] Lithium secondary batteries are rechargeable and have an energy density per unit weight that is three times higher than that of conventional lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries, and they are capable of fast charging. Therefore, they are commercialized for use in laptops, cell phones, power tools, and electric bicycles, and active research and development is being conducted to further improve energy density.

[0004] Lithium secondary batteries currently on the market are lithium-ion batteries that use electrolytes containing flammable organic solvents. This poses safety concerns, as they can explode or cause fire in the event of collisions or penetrations. Therefore, all-solid-state batteries, which utilize solid electrolytes instead of the electrolytes, are being proposed. Among lithium secondary batteries, all-solid-state batteries are comprised entirely of solid materials, specifically those that utilize solid electrolytes.

[0005]

[0006] One embodiment provides an additive for a lithium secondary battery that can suppress a ignition phenomenon due to abnormal heat generation, regardless of the form of the lithium secondary battery.

[0007]

[0008] One embodiment provides an additive for a lithium secondary battery represented by the following chemical formula 1:

[0009] [Chemical Formula 1]

[0010] .

[0011]

[0012] An additive for a lithium secondary battery according to one embodiment can be applied to at least one component of a lithium secondary battery, regardless of the form of the lithium secondary battery, to suppress a ignition phenomenon due to abnormal heat generation.

[0013]

[0014] Figures 1 and 2 are cross-sectional views schematically illustrating an all-solid-state battery according to one embodiment.

[0015] Figure 3 is a TGA thermal analysis diagram of the additive of Synthesis Example 1 (a compound represented by Chemical Formula 1-1a).

[0016] Figure 4 is a TGA thermal analysis diagram of the additive of Synthesis Example 2 (compound represented by Chemical Formula 1-1b).

[0017] Figure 5 is a TGA thermal analysis diagram of the additive of Synthesis Example 3 (compound represented by Chemical Formula 1-2a).

[0018] Figure 6 is a TGA thermal analysis diagram of the additive of Synthesis Example 4 (compound represented by Chemical Formula 1-3a).

[0019] Figure 7 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 1 (compound represented by Chemical Formula 1-1a) was applied.

[0020] Figure 8 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 2 (compound represented by Chemical Formula 1-1b) was applied.

[0021] Figure 9 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 3 (compound represented by Chemical Formula 1-2a) was applied.

[0022] Figure 10 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 4 (compound represented by Chemical Formula 1-3a) was applied.

[0023] Figure 11 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 5 (compound represented by Chemical Formula 1-4a) was applied.

[0024] Below, specific implementation examples are described in detail to facilitate their implementation by those skilled in the art. However, the present invention may be implemented in various different forms and is not limited to the implementation examples described herein.

[0025] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0026] Here, “combination of these” means a mixture, laminate, composite, copolymer, alloy, blend, reaction product, etc. of the components.

[0027] It should be understood that the terms "include," "comprising," or "having" herein are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0028] To clearly illustrate various layers and regions in the drawings, their thicknesses are enlarged, and similar parts are designated by the same drawing reference numerals throughout the specification. When an element such as a layer, film, region, or plate is said to be "over" or "on" another element, this includes not only the case where it is "directly over" the other element, but also the case where there is another element in between. Conversely, when an element is said to be "directly over" another element, it means that there is no other element in between.

[0029] Also, the term "layer" here includes not only a shape formed on the entire surface when observed in a plan view, but also a shape formed on a portion of the surface.

[0030] In addition, the average particle diameter and average size, etc. can be measured by methods widely known to those skilled in the art, for example, by measuring with a particle size analyzer, or by measuring with a transmission electron microscope photograph or a scanning electron microscope photograph. Alternatively, the size, etc. can be measured using a dynamic light scattering method, and the data can be analyzed to count the number of particles for each particle size range, and then the average particle diameter value can be obtained by calculating from the counted number. Unless otherwise defined, the average particle diameter is measured with a particle size analyzer and means the diameter (D50) of particles in the particle size distribution with a cumulative volume of 50% by volume.

[0031] “Or” is not interpreted as exclusive, for example, “A or B” is interpreted as including A, B, A+B, etc.

[0032] Unless otherwise specified herein, "substitution" means that at least one hydrogen atom in a compound is substituted with a halogen atom (F, Cl, Br, I), a hydroxy group, a C1 to C20 alkoxy group, a nitro group, a cyano group, an amine group, an imino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, an ether group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C3 to C20 cycloalkyl group, a C3 to C20 cycloalkenyl group, a C3 to C20 cycloalkynyl group, a C2 to C20 heterocycloalkyl group, a C2 to C20 heterocycloalkenyl group, It means substituted with a C2 to C20 heterocycloalkynyl group or a combination thereof.

[0033] Unless otherwise specified herein, the terms “heterocycloalkyl group,” “heterocycloalkenyl group,” “heterocycloalkynyl group,” and “heterocycloalkylene group” mean that at least one N, O, S, or P heteroatom is present in the ring compound of cycloalkyl, cycloalkenyl, cycloalkynyl, and cycloalkylene, respectively.

[0034] Unless otherwise defined in the chemical formulas herein, if a chemical bond is not drawn at a position where a chemical bond should be drawn, it means that a hydrogen atom is bonded at that position.

[0035] Unless otherwise defined herein, “*” means a part connected to the same or different atoms or chemical formulas.

[0036]

[0037] (additive)

[0038] One embodiment provides an additive for a lithium secondary battery represented by the following chemical formula 1:

[0039] [Chemical Formula 1]

[0040]

[0041] In the above chemical formula 1,

[0042] X1 is the same or different and is a hydrogen atom or a halogen atom;

[0043] A is a substituent represented by the following chemical formula 2, a substituent represented by the following chemical formula 3, a substituent represented by the following chemical formula 4, a substituent represented by the following chemical formula 5, or a substituted or unsubstituted C1 to C20 alkyl group;

[0044] [Chemical Formula 2]

[0045]

[0046] In the above chemical formula 2,

[0047] Z1 is a carbon atom or a silicon atom,

[0048] L1 is the same or different and is a single bond or a substituted or unsubstituted C1 to C20 alkylene group;

[0049] R1 is the same or different and is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, or a substituent represented by the following chemical formula 5;

[0050] [Chemical Formula 3]

[0051]

[0052] In the above chemical formula 3,

[0053] Z2 is a nitrogen atom or a phosphorus atom;

[0054] L2 is a single bond or a substituted or unsubstituted C1 to C20 alkylene group;

[0055] R2 is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, or a substituent represented by the following chemical formula 5;

[0056] [Chemical Formula 4]

[0057]

[0058] L3 is the same or different and is a single bond, a disulfide bond, a substituted or unsubstituted C1 to C20 alkylene group, or a combination thereof;

[0059] R3 is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, or a substituent represented by the following chemical formula 5;

[0060] [Chemical Formula 5]

[0061]

[0062] In the above chemical formula 5,

[0063] X2 is the same or different and is a hydrogen atom or a halogen atom.

[0064]

[0065] An additive of one embodiment comprises at least one azide group (azide, -N=N) per molecule. +=N - ) is a compound containing the azide group. The azide group decomposes at a high temperature of 140°C or higher to generate nitrogen (N2), which is converted into a nitrene group (-N).

[0066] The above nitrene group reacts with other components of a lithium secondary battery to form a film, rapidly reducing ionic conductivity, and has the effect of shutting down the lithium secondary battery at a temperature lower than the ignition temperature.

[0067] Accordingly, the additive of one embodiment can suppress a ignition phenomenon due to abnormal heat generation of a lithium secondary battery compared to a compound that does not contain an azide group.

[0068] In addition, the additive of one embodiment corresponds to a universal additive that can be used regardless of the form of the lithium secondary battery.

[0069] Hereinafter, the additive of the above embodiment will be described in detail.

[0070]

[0071] The above chemical formula 1 can be represented by any one of the following chemical formulas 1-1 to 1-4:

[0072] [Chemical Formula 1-1]

[0073]

[0074] [Chemical Formula 1-2]

[0075]

[0076] [Chemical Formula 1-3]

[0077]

[0078] [Chemical Formula 1-4]

[0079]

[0080] In the above chemical formulas 1-1 to 1-4,

[0081] Z1 is a carbon atom or a silicon atom;

[0082] Z2 is a nitrogen atom or a phosphorus atom;

[0083] X1 is the same or different and is a hydrogen atom or a halogen atom;

[0084] X2 is the same or different and is a hydrogen atom or a halogen atom;

[0085] L1 is the same or different and is a single bond or a substituted or unsubstituted C1 to C20 alkylene group;

[0086] L2 is the same or different and is a single bond or a substituted or unsubstituted C1 to C20 alkylene group;

[0087] L3 is the same or different and is a single bond, a disulfide bond, a substituted or unsubstituted C1 to C20 alkylene group, or a combination thereof;

[0088] R4 is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group.

[0089]

[0090] Z1 can be a carbon atom.

[0091] Z2 may be a nitrogen atom.

[0092] X1 can be all hydrogen atoms or all halogen atoms.

[0093] X2 can be all hydrogen atoms or all halogen atoms.

[0094] L1 can be any methylene group.

[0095] L2 can be all ethylene groups.

[0096] L3 may be a single bond; or a combination of a disulfide bond and an ethylene group.

[0097] R4 may be a substituted or unsubstituted C1 to C20 alkyl group.

[0098]

[0099] Representative examples of the above additives are as follows:

[0100] [Chemical Formula 1-1a]

[0101]

[0102] [Chemical Formula 1-1b]

[0103]

[0104] [Chemical Formula 1-2a]

[0105]

[0106] [Chemical Formula 1-3a]

[0107]

[0108] [Chemical Formula 1-4a]

[0109] . .

[0110]

[0111] (electrolyte layer, anode, cathode, and all-solid-state battery)

[0112] In another embodiment, an electrolyte layer for a lithium secondary battery is provided, comprising the additive of one embodiment. In another embodiment, a positive electrode for a lithium secondary battery is provided, comprising the additive of one embodiment. In another embodiment, a negative electrode for a lithium secondary battery is provided, comprising the additive of one embodiment.

[0113] In another embodiment, a lithium secondary battery is provided, comprising: a positive electrode; a negative electrode; and an electrolyte layer disposed between the positive electrode and the negative electrode, wherein at least one layer of the positive electrode, the negative electrode, and the electrolyte layer comprises an additive of one embodiment.

[0114] The above lithium secondary battery may be an all-solid-state battery, a semi-solid-state battery, a lithium metal battery, or a lithium ion battery.

[0115]

[0116] All-solid-state batteries

[0117] For example, the lithium secondary battery may be an all-solid-state battery. The all-solid-state battery may also be expressed as an all-solid-state secondary battery, or an all-solid-state lithium secondary battery.

[0118] FIG. 1 is a cross-sectional view of an all-solid-state battery according to one embodiment. Referring to FIG. 1, the all-solid-state battery (100) may have a structure in which an electrode assembly in which a negative electrode (400) including a negative electrode collector (401) and a negative electrode active material layer (403), a solid electrolyte layer (300), and a positive electrode (200) including a positive electrode active material layer (203) and a positive electrode collector (201) are laminated is housed in a case such as a pouch. The all-solid-state battery (100) may further include an elastic layer (500) on the outer side of at least one of the positive electrode (200) and the negative electrode (400). Although FIG. 1 illustrates one electrode assembly including a negative electrode (400), a solid electrolyte layer (300), and a positive electrode (200), an all-solid-state battery may be manufactured by laminating two or more electrode assemblies.

[0119] An all-solid-state battery according to one embodiment can be manufactured by sequentially stacking a positive electrode, a solid electrolyte, and a negative electrode to prepare a layered body, and then pressurizing the stacked body.

[0120] The pressurization may be performed at a temperature of, for example, 25°C to 90°C, and at a pressure of 550 MPa or less, or 500 MPa or less, for example, 400 MPa to 500 MPa. The pressurization may be, for example, an isostatic press, a roll press, or a plate press.

[0121] The above-mentioned all-solid-state battery may be a unit battery having a structure of positive electrode / solid electrolyte layer / negative electrode, a bi-cell having a structure of positive electrode / solid electrolyte layer / negative electrode / solid electrolyte layer / positive electrode, or a laminated battery in which the structure of the unit battery is repeated.

[0122] The shape of the above-mentioned all-solid-state battery is not particularly limited, and may be, for example, coin-shaped, button-shaped, sheet-shaped, stacked, cylindrical, flat, etc. In addition, the above-mentioned all-solid-state battery can be applied to medium- to large-sized batteries used in electric vehicles, etc. For example, the above-mentioned all-solid-state battery can be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). In addition, it can be applied to energy storage systems (ESS) that require a large amount of power storage, and can also be applied to electric bicycles or power tools, etc.

[0123]

[0124] solid electrolyte layer

[0125] The solid electrolyte layer includes a solid electrolyte. In this case, the electrolyte layer may be a solid electrolyte layer.

[0126] The electrolyte layer may include the additive. Of the total 100 wt% of the electrolyte layer, the additive may be included in an amount of 0.1 to 10 wt%, or 0.1 to 5 wt%. In addition, the weight ratio of the solid electrolyte to the additive in the electrolyte layer may be 99.9:0.01 to 90:10, or 99:1 to 90:10. Within this range, the shutdown effect by the additive may be appropriately implemented.

[0127] The above solid electrolyte may be a type of inorganic solid electrolyte, and may include, for example, a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a halide-based solid electrolyte, or a combination thereof.

[0128] Sulfide-based solid electrolyte

[0129] Sulfide-based solid electrolytes include, for example, Li2S-P2S5, Li2S-P2S5--LiX (where X is a halogen element, for example, I or Cl), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z. m S n (m, n are integers, Z is Ge, Zn or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are integers, and M is P, Si, Ge, B, Al, Ga or In), or a combination thereof.

[0130] A sulfide-based solid electrolyte can be obtained, for example, by mixing Li2S and P2S5 in a molar ratio of 50:50 to 90:10, or 50:50 to 80:20, and optionally heat-treating them. Within the above mixing ratio range, a sulfide-based solid electrolyte having excellent ionic conductivity can be produced. Here, the ionic conductivity can be further improved by further including other components such as SiS2, GeS2, and B2S3.

[0131] Methods for mixing sulfur-containing raw materials for producing sulfide-based solid electrolytes include mechanical milling or the solution method. Mechanical milling involves placing raw materials in a ball mill reactor and vigorously stirring them to finely atomize and mix them. Using the solution method, the raw materials are mixed in a solvent to obtain a solid electrolyte as a precipitate. Furthermore, heat treatment after mixing can solidify the crystals of the solid electrolyte and improve ionic conductivity. For example, a sulfide-based solid electrolyte can be produced by mixing sulfur-containing raw materials and heat-treating them twice or more, resulting in a sulfide-based solid electrolyte with high ionic conductivity and robustness.

[0132] According to one embodiment, sulfide-based solid electrolyte particles can be manufactured through, for example, a first heat treatment in which sulfur-containing raw materials are mixed and calcined at 120°C to 350°C, and a second heat treatment in which the first heat treatment result is mixed and calcined at 350°C to 800°C. The first heat treatment and the second heat treatment can each be performed in an inert gas or nitrogen atmosphere. The first heat treatment can be performed for 1 to 10 hours, and the second heat treatment can be performed for 5 to 20 hours. The first heat treatment can have the effect of milling small raw materials, and the second heat treatment can synthesize the final solid electrolyte. Through two or more such heat treatments, a high-performance sulfide-based solid electrolyte with high ionic conductivity and robustness can be obtained, and such a solid electrolyte can be said to be suitable for mass production. The temperature of the first heat treatment may be, for example, 150°C to 330°C, or 200°C to 300°C, and the temperature of the second heat treatment may be, for example, 380°C to 700°C, or 400°C to 600°C.

[0133] For example, the sulfide-based solid electrolyte particles may include argyrodite-type sulfides. The argyrodite-type sulfide-based solid electrolyte particles may have an ionic conductivity of 10, which is the ionic conductivity of a typical liquid electrolyte at room temperature. -4 10 inland -2 It has a high ionic conductivity approaching the S / cm range, can form a close bond between a positive electrode active material and a solid electrolyte without causing a decrease in ionic conductivity, and can further form a close interface between an electrode layer and a solid electrolyte layer. An all-solid-state secondary battery including this can have improved battery performance, such as rate characteristics, Coulombic efficiency, and cycle life characteristics.

[0134] The argyrodite-type sulfide-based solid electrolyte particles may include, for example, a compound represented by the chemical formula 21 below.

[0135] [Chemical Formula 21]

[0136] (Li a M 1 b M 2 c )(P d M 3 e )(S f M 4 g )X h

[0137] In the above chemical formula 21, 4≤a≤8, and M 1 is Mg, Cu, Ag, or a combination thereof, and 0≤b<0.5, and M 2 is Na, K, or a combination thereof, 0≤c<0.5, and M 3 is Sn, Zn, Si, Sb, Ge, or a combination thereof, and 0 <d<4, 0≤e<1 이고, M 4 is O, SO n , or a combination thereof, and 1.5≤n≤5, 3≤f≤12, 0≤g<2, and X is F, Cl, Br, I, or a combination thereof, and 0≤h≤2.

[0138] For example, in chemical formula 21, a halide element (X) may be included as an essential element, in which case 0 <h≤2로 표시될 수 있다. 일 예로 화학식 21에 M 1 Elements may be required, in which case 0 <b<0.5로 표시될 수 있다. 화학식 21에서 M 3 can be understood as an element substituted in place of P and 0 <e<1일 수 있다. 화학식 21에서 M 4 is substituted in the S position, for example, 0 <g<2일 수 있으며 S의 비율인 f는 예를 들어 3≤f≤7일 수 있다. M 4 Go SO n If SO n It can be, for example, S4O6, S3O6, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, SO4, or SO5, and can be, for example, SO4.

[0139] For example, in chemical formula 21, a+b+c+h=7, d+e=1, and f+g+h=6.

[0140] As a specific example, argyrodite-type sulfide-based solid electrolyte particles include Li3PS4 and Li7P3S. 11 , Li7PS6, Li6PS5Cl, Li6PS5Br, Li 5.8 PS 4.8 Cl 1.2 , Li 6.2 PS 5.2 Br 0.8 , Li 5.75 PS 4.75 Cl 1.25 , (Li 5.69 Cu 0.06 )PS 4.75 Cl 1.25 , (Li 5.72 Cu 0.03 )PS 4.75 Cl 1.25 , (Li 5.69 Cu 0.06 )P(S 4.70 (SO4) 0.05 )Cl 1.25 , (Li 5.69 Cu0.06 )P(S 4.60 (SO4) 0.15 )Cl 1.25 , (Li 5.72 Cu 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 , (Li 5.72 Na 0.03 )P(S 4.725 (SO4) 0.025 )Cl 1.25 , Li 5.75 P(S 4.725 (SO4) 0.025 )Cl 1.25 , or combinations thereof, but are not limited thereto.

[0141] An argyrodite-type sulfide-based solid electrolyte can be manufactured, for example, by mixing lithium sulfide and phosphorus sulfide, optionally a lithium halide. After mixing these, a heat treatment may be performed. The heat treatment may include, for example, two or more heat treatment steps. Here, manufacturing an argyrodite-type sulfide-based solid electrolyte may include, for example, a first heat treatment of mixing raw materials and calcining at 120°C to 350°C, and a second heat treatment of mixing the resultant of the first heat treatment again and calcining at 350°C to 800°C.

[0142] The average particle size (D50) of the sulfide-based solid electrolyte particles may be, for example, 0.1 ㎛ to 5.0 ㎛ or 0.1 ㎛ to 3.0 ㎛, and may be small particles of 0.1 ㎛ to 1.9 ㎛ or large particles of 2.0 ㎛ to 5.0 ㎛. The sulfide-based solid electrolyte particles may be a mixture of small particles having an average particle size of 0.1 ㎛ to 1.9 ㎛ and large particles having an average particle size of 2.0 ㎛ to 5.0 ㎛. The average particle size of the sulfide-based solid electrolyte particles may be measured from an electron microscope image, and for example, a particle size distribution may be obtained by measuring the size (diameter or major axis length) of about 20 particles in a scanning electron microscope image, and D50 may be calculated from this.

[0143] Oxide-based solid electrolyte

[0144] Oxide-based solid electrolytes include, for example, Li 1+x Ti 2-x Al(PO4)3(LTAP)(0≤x≤4), Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 <x<2, 0≤y<3), BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT)(0≤x<1, 0≤y<1), PB(Mg3Nb 2 / 3 )O3-PbTiO3(PMN-PT), HfO2, SrTiO3, SnO2, CeO2, Na2O, MgO, NiO, CaO, BaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiO2, lithium phosphate (Li3PO4), lithium titanium phosphate (Li x Ti y (PO4)3, 0 <x<2, 0<y<3), Li 1+x+y (Al, Ga) x (Ti, Ge) 2-x Si y P 3-y O12 (0≤x≤1, 0≤y≤1), lithium lanthanum titanate (Li x La y TiO3, 0 <x<2, 0<y<3), Li2O, LiAlO2, Li2O-Al2O3-SiO2-P2O5-TiO2-GeO2계 세라믹스, 가넷(Garnet)계 세라믹스 Li 3+x La3M2O 12 (M= Te, Nb, or Zr; x is an integer from 1 to 10), or mixtures thereof.

[0145] Halide-based solid electrolyte

[0146] The solid electrolyte layer may further include, for example, a halide-based solid electrolyte. The halide-based solid electrolyte contains a halogen element as a main component, and may mean that the ratio of the halide element to all elements constituting the solid electrolyte is 50 mol% or more, 70 mol% or more, 90 mol% or more, or 100 mol%. For example, the halide-based solid electrolyte may not contain a sulfur element.

[0147] The halide-based solid electrolyte may contain lithium element, a metal element other than lithium, and a halogen element. The metal element other than lithium may be Al, As, B, Bi, Ca, Cd, Co, Cr, Fe, Ga, Hf, In, Mg, Mn, Ni, Sb, Sc, Sn, Ta, Ti, Y, Zn, Zr, or a combination thereof. The halogen element may be F, Cl, Br, I, or a combination thereof, and may be Cl, Br, or a combination thereof. The halide-based solid electrolyte may contain, for example, Li aM1X6 (M is Al, As, B, Bi, Ca, Cd, Co, Cr, Fe, Ga, Hf, In, Mg, Mn, Ni, Sb, Sc, Sn, Ta, Ti, Y, Zn, Zr, or a combination thereof, X is F, Cl, Br, I, or a combination thereof, and 2≤a≤3) can be represented. The halide-based solid electrolyte is, for example, Li2ZrCl6, Li 2.7 Y 0.7 Zr 0.3 Cl6, Li 2.5 Y 0.5 Zr 0.5 Cl6, Li 2.5 In 0.5 Zr 0.5 Cl6, Li2In 0.5 Zr 0.5 Cl6, Li3YBr6, Li3YCl6, Li3YBr2Cl4, Li3YbCl6, Li 2.6 Hf 0.4 Yb 0.6 Cl6, or combinations thereof, but is not limited thereto.

[0148] bookbinder

[0149] The solid electrolyte layer may further include a binder. Binders include, for example, nitrile-butadiene rubber, hydrogenated nitrile-butadiene rubber, styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluoroelastomer, natural rubber, polydimethylsiloxane, polyethylene oxide, polyvinylpyrrolidone, polyvinylpyridine, chlorosulfonated polyethylene, polyvinyl alcohol, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, polyamideimide, polyimide, poly(meth)acrylate, polyacrylonitrile, polystyrene, polyurethane, and the like. copolymers, or combinations thereof.

[0150] The binder may be included in an amount of 0.1 wt% to 3 wt% based on 100 wt% of the solid electrolyte layer, for example, 0.5 wt% to 2 wt%, or 0.5 wt% to 1.5 wt%. When the binder is included in the above range, the components within the solid electrolyte layer can be well combined without lowering the ionic conductivity of the solid electrolyte, thereby improving the durability and reliability of the battery.

[0151] Other ingredients

[0152] The solid electrolyte layer may optionally further comprise an alkali metal salt, and / or an ionic liquid, and / or a conductive polymer.

[0153] The above alkali metal salt may be, for example, a lithium salt. The content of the lithium salt in the solid electrolyte layer may be 1 M or more, for example, 1 M to 4 M. In this case, the lithium salt may improve ion conductivity by enhancing the lithium ion mobility of the solid electrolyte layer.

[0154] The lithium salt may be applied without limitation on type, and may include, for example, LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiSCN, LiN(CN)2, lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium difluorobis(oxalato)phosphate (LiDFBP), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(pentafluoroethanesulfonyl)imide (LiBETI), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, or a combination thereof.

[0155] For example, the lithium salt may be an imide-based lithium salt such as LiTFSI, LiFSI, LiBETI, or a combination thereof. The imide-based lithium salt can maintain or improve ionic conductivity by appropriately maintaining chemical reactivity with the ionic liquid.

[0156] Ionic liquids are salts or molten salts that are composed only of ions and are liquid at room temperature, with a melting point below room temperature.

[0157] The ionic liquid comprises a) one or more cations selected from ammonium, pyrrolidinium, pyridinium, pyrimidinium, imidazolium, piperidinium, pyrazolium, oxazolium, pyridazinium, phosphonium, sulfonium, trizolium, and mixtures thereof, and b) 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 - It may be a compound containing one or more anions selected from among.

[0158] The ionic liquid may be at least one selected from the group consisting of, for example, N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidinium bis(3-trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide.

[0159] In the solid electrolyte layer, the weight ratio of the solid electrolyte to the ionic liquid may be 0.1:99.9 to 90:10, for example, 10:90 to 90:10, 20:80 to 90:10, 30:70 to 90:10, 40:60 to 90:10, or 50:50 to 90:10. A solid electrolyte layer satisfying the above range can maintain or improve ionic conductivity by improving the electrochemical contact area with the electrode. Accordingly, the energy density, discharge capacity, rate characteristics, etc. of the all-solid-state secondary battery can be improved.

[0160]

[0161] anode

[0162] In one embodiment, the device comprises a current collector and a positive electrode active material layer positioned on the current collector, wherein the positive electrode active material layer comprises a positive electrode active material and may optionally comprise a solid electrolyte, a binder, and / or a conductive material. In addition, the positive electrode active material layer may comprise the additive.

[0163] positive electrode active material

[0164] A compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) can be used as a cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0165] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, lithium-rich layered oxide, or a combination thereof.

[0166] For example, the cathode active material may be a high-nickel cathode active material in which the nickel content is 80 mol% or more based on 100 mol% of metals excluding lithium in a lithium transition metal composite oxide. The nickel content in the high-nickel cathode active material may be 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more, and 99 mol% or less based on 100 mol% of metals excluding lithium. The high-nickel cathode active material can realize high capacity and thus can be applied to high-capacity, high-density lithium secondary batteries.

[0167] As a more specific example, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2-c D c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li a Mn 2-b X b O 4-c D c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤0.5, 0 < α < 2);Li a Ni 1-b-c Mn b X c O 2-α D α(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.5, 0 < α < 2);Li a Ni b Co c L 1 d G e O2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.1);; Li a NiG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a CoG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a Mn 1-b G b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a Mn2G b O4(0.90 ≤ a ≤1.8, 0.001 ≤ b ≤ 0.1); Li a Mn 1-g G g PO4(0.90 ≤ a ≤ 1.8, 0 ≤ g ≤ 0.5); Li (3-f) Fe2(PO4)3(0 ≤ f ≤ 2); Li a FePO4(0.90 ≤ a ≤ 1.8)

[0168] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; Z is Cr, V, Fe, Sc, Y, or a combination thereof; L 1 is Mn, Al or a combination thereof.

[0169] The cathode active material may include, for example, a lithium nickel-based oxide represented by the following chemical formula 11, a lithium cobalt-based oxide represented by the following chemical formula 12, a lithium iron phosphate-based compound represented by the following chemical formula 13, a cobalt-free lithium nickel-manganese-based oxide represented by the following chemical formula 14, or a combination thereof.

[0170] [Chemical Formula 11]

[0171] Li a1 Ni x1 M 1 y1 M 2 z1 O 2-b1 X b1

[0172] In the above chemical formula 11, 0.9≤a1≤1.8, 0.3≤x1≤1, 0≤y1≤0.7, 0≤z1≤0.7, 0.9≤x1+y1+z1≤1.1, and 0≤b1≤0.1, and M 1 and M 2 are each independently one or more elements selected from the group consisting of Al, B, Ba, Ca, Ce, Co, Cr, Cu, Fe, Mg, Mn, Mo, Nb, Si, Sn, Sr, Ti, V, W, and Zr, and X is one or more elements selected from the group consisting of F, P, and S.

[0173] In the above chemical formula 1, 0.6≤x1≤1, 0≤y1≤0.4, and 0≤z1≤0.4, or 0.8≤x1≤1, 0≤y1≤0.2, and 0≤z1≤0.2.

[0174] [Chemical Formula 12]

[0175] Li a2 Co x2 M 3 y2 O 2-b2 X b2

[0176] In the above chemical formula 12, 0.9≤a2≤1.8, 0.7≤x2≤1, 0≤y2≤0.3, 0.9≤x2+y2≤1.1, and 0≤b2≤0.1, and M 3is one or more elements selected from the group consisting of Al, B, Ba, Ca, Ce, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Se, Si, Sn, Sr, Ti, V, W, Y, Zn and Zr, and X is one or more elements selected from the group consisting of F, P and S.

[0177] [Chemical Formula 13]

[0178] Li a3 Fe x3 M 4 y3 PO 4-b3 X b3

[0179] In the above chemical formula 13, 0.9≤a3≤1.8, 0.6≤x3≤1, 0≤y3≤0.4, and 0≤b3≤0.1, and M 4 is one or more elements selected from the group consisting of Al, B, Ba, Ca, Ce, Co, Cr, Cu, Mg, Mn, Mo, Ni, Se, Si, Sn, Sr, Ti, V, W, Y, Zn and Zr, and X is one or more elements selected from the group consisting of F, P and S.

[0180] [Chemical Formula 14]

[0181] Li a4 Ni x4 Mn y4 M 5 z4 O 2-b4 X b4

[0182] In the above chemical formula 14, 0.9≤a2≤1.8, 0.8≤x4<1, 0 <y4≤0.2, 0≤z4≤0.2, 0.9≤x4+y4+z4≤1.1, 및 0≤b4≤0.1이고 M 5 is one or more elements selected from the group consisting of Al, B, Ba, Ca, Ce, Cr, Fe, Mg, Mo, Nb, Si, Sn, Sr, Ti, V, W, and Zr, and X is one or more elements selected from the group consisting of F, P, and S.

[0183] The average particle diameter (D50) of the positive electrode active material may be 1 μm to 25 μm, for example, 3 μm to 25 μm, 1 μm to 20 μm, 1 μm to 18 μm, 3 μm to 15 μm, or 5 μm to 15 μm. For example, the positive electrode active material may include small particles having an average particle diameter (D50) of 1 μm to 9 μm and large particles having an average particle diameter (D50) of 10 μm to 25 μm. A positive electrode active material having such a particle diameter range can be harmoniously mixed with other components within a positive electrode active material layer and can realize high capacity and high energy density. Here, the average particle diameter may be obtained by selecting 20 or so random particles from a scanning electron microscope image of the positive electrode active material, measuring their particle diameters (diameter, major axis, or major axis length), obtaining a particle size distribution, and then taking the diameter (D50) of particles having a cumulative volume of 50% by volume from the particle size distribution as the average particle diameter.

[0184] The above-mentioned positive electrode active material may be in the form of a secondary particle formed by agglomeration of a plurality of primary particles, or may be in the form of a single particle. In addition, the above-mentioned positive electrode active material may be spherical or nearly spherical in shape, or may be polyhedral or irregular in shape.

[0185] Meanwhile, the positive electrode active material may include a buffer layer on the particle surface. The buffer layer may be expressed as a coating layer, a protective layer, etc., and may play a role in lowering the interfacial resistance between the positive electrode active material and the sulfide-based solid electrolyte particles. For example, the buffer layer may include a lithium-metal-oxide, wherein the metal may be one or more elements selected from the group consisting of Al, B, Ca, Ce, Cr, Fe, Mg, Mo, Nb, Si, Sn, Sr, Ta, V, W, and Zr. The lithium-metal-oxide is excellent in lowering the interfacial resistance between the positive electrode active material and the solid electrolyte particles while improving the performance of the positive electrode active material by facilitating the movement of lithium ions and electron conduction.

[0186] The positive electrode active material may be included in an amount of 55 wt% to 99.5 wt% based on 100 wt% of the positive electrode active material layer, for example, 65 wt% to 95 wt%, or 75 wt% to 91 wt%.

[0187] bookbinder

[0188] The binder helps the positive electrode active material particles adhere well to each other and also helps the positive electrode active material adhere well to the current collector. Representative examples of binders include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, nylon, etc.

[0189] Challenge

[0190] Conductive materials are used to impart conductivity to electrodes, and any material that does not cause chemical changes and is electronically conductive can be used in the battery. Examples of conductive materials include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metallic materials containing copper, nickel, aluminum, silver, etc. in the form of metal powder or metal fibers; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0191] The content of the binder and the conductive agent may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0192] The positive electrode active material layer may optionally further include a solid electrolyte. The solid electrolyte may include, for example, a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a halide-based solid electrolyte, or a combination thereof, and a detailed description thereof will be provided later in the section on the solid electrolyte layer.

[0193] With respect to 100 wt% of the positive electrode active material layer, the solid electrolyte may be included in an amount of 0.1 wt% to 35 wt%, for example, 1 wt% to 35 wt%, 5 wt% to 30 wt%, 8 wt% to 25 wt%, or 10 wt% to 20 wt%.

[0194] In the positive electrode active material layer, the positive electrode active material may be comprised in an amount of 65 to 99 wt% and the solid electrolyte in an amount of 1 to 35 wt%, based on 100 wt% of the total of the positive electrode active material and the solid electrolyte, for example, the positive electrode active material may be comprised in an amount of 80 to 90 wt% and the solid electrolyte in an amount of 10 to 20 wt%. When the solid electrolyte is comprised in the positive electrode in such an amount, the efficiency and life characteristics of the all-solid-state secondary battery can be improved without reducing the capacity.

[0195] Al may be used as the above current collector, but is not limited thereto.

[0196]

[0197] cathode

[0198] An anode for an all-solid-state battery may include, for example, a current collector and a negative electrode active material layer positioned on the current collector. The negative electrode active material layer includes a negative electrode active material and may further include a binder, a conductive material, and / or a solid electrolyte. In addition, the negative electrode active material layer may include the additives described above.

[0199] The above negative active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0200] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in an amorphous, plate-like, flake-like, spherical, or fibrous form, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0201] As the above lithium metal alloy, an alloy of lithium and one or more metals selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn can be used.

[0202] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used, and the Si-based negative electrode active material may be silicon, a silicon-carbon composite, or SiO. x(0<x<2), Si-Q 합금(상기 Q는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 15족 원소, 16족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Si은 아님), 상기 Sn계 음극 활물질로는 Sn, SnO2, Sn-R 합금(상기 R은 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 15족 원소, 16족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Sn은 아님) 등을 들 수 있고, 또한 이들 중 적어도 하나와 SiO2를 혼합하여 사용할 수도 있다. 상기 원소 Q 및 R로는 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, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, 및 이들의 조합으로 이루어진 군에서 선택되는 것을 사용할 수 있다.

[0203] The silicon-carbon composite may be, for example, a silicon-carbon composite including a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core. The crystalline carbon may be artificial graphite, natural graphite, or a combination thereof. As the amorphous carbon precursor, coal pitch, mesophase pitch, petroleum pitch, coal oil, petroleum heavy oil, or a polymer resin such as a phenol resin, a furan resin, or a polyimide resin may be used. At this time, the content of silicon may be 10 wt% to 50 wt% with respect to the total weight of the silicon-carbon composite. In addition, the content of the crystalline carbon may be 10 wt% to 70 wt% with respect to the total weight of the silicon-carbon composite, and the content of the amorphous carbon may be 20 wt% to 40 wt% with respect to the total weight of the silicon-carbon composite. In addition, the thickness of the amorphous carbon coating layer may be 5 nm to 100 nm.

[0204] The average particle diameter (D50) of the above silicon particles may be 10 nm to 20 μm, for example, 10 nm to 200 nm. The silicon particles may exist in an oxidized form, and at this time, the atomic content ratio of Si:O in the silicon particles, which indicates the degree of oxidation, may be 99:1 to 33:67. The silicon particles may be SiO x It can be a particle, in which case SiO x The range of x in can be greater than 0 and less than 2.

[0205] The above Si-based negative electrode active material or Sn-based negative electrode active material can be used in combination with a carbon-based negative electrode active material. The mixing ratio of the Si-based negative electrode active material or Sn-based negative electrode active material and the carbon-based negative electrode active material can be 1:99 to 90:10 by weight.

[0206] The content of the negative active material in the above negative active material layer may be 95 wt% to 99 wt% with respect to the total weight of the negative active material layer.

[0207] In one embodiment, the negative electrode active material layer further includes a binder and may optionally further include a conductive material. The content of the binder in the negative electrode active material layer may be 1 wt% to 5 wt% based on the total weight of the negative electrode active material layer. In addition, when the negative electrode active material layer further includes a conductive material, the negative electrode active material layer may include 90 wt% to 98 wt% of the negative electrode active material, 1 wt% to 5 wt% of the binder, and 1 wt% to 5 wt% of the conductive material.

[0208] The above binder serves to adhere the negative electrode active material particles well to each other and also to adhere the negative electrode active material well to the current collector. The binder may be an insoluble binder, a water-soluble binder, or a combination thereof.

[0209] The above-mentioned non-aqueous binder may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, a polymer containing ethylene oxide, an ethylene propylene copolymer, polystyrene, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or a combination thereof.

[0210] The water-soluble binder may be a rubber-based binder or a polymer resin binder. The rubber-based binder may be selected from styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluororubber, and combinations thereof. The polymer resin binder may be selected from polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenol resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0211] When a water-soluble binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included. The cellulose-based compound may be a mixture of one or more of carboxymethyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, or an alkali metal salt thereof. The alkali metal may be Na, K, or Li. The amount of such thickener may be 0.1 to 3 parts by weight based on 100 parts by weight of the negative electrode active material.

[0212] The conductive material is used to impart conductivity to the electrode, and any material that does not cause chemical changes and has electronic conductivity can be used. The conductive material may include, for example, carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metal-based materials in the form of metal powder or metal fibers, including copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0213] The negative electrode current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0214] Meanwhile, as an example, the above-mentioned all-solid-state battery negative electrode may be a precipitation-type negative electrode. The precipitation-type negative electrode refers to a negative electrode that does not have a negative electrode active material when the battery is assembled, but in which lithium metal or the like is precipitated when the battery is charged, and this acts as a negative electrode active material.

[0215] Fig. 2 is a schematic cross-sectional view of an all-solid-state battery including a precipitation-type negative electrode. Referring to Fig. 2, the precipitation-type negative electrode (400') may include a current collector (401) and a negative electrode coating layer (405) positioned on the current collector. An all-solid-state battery including such a precipitation-type negative electrode (400') starts initial charging in a state in which no negative electrode active material is present, and upon charging, high-density lithium metal or the like is precipitated between the current collector (401) and the negative electrode coating layer (405) to form a lithium metal layer (404), which may function as a negative electrode active material. Accordingly, in an all-solid-state battery that has been charged at least once, the precipitation-type negative electrode (400') may include a current collector (401), a lithium metal layer (404) positioned on the current collector, and a negative electrode coating layer (405) positioned on the metal layer. The above lithium metal layer (404) refers to a layer in which lithium metal, etc. is precipitated during the charging process of the battery, and may be referred to as a metal layer or a negative electrode active material layer.

[0216] The above cathode coating layer (405) may include a metal and / or carbon material that acts as a catalyst.

[0217] The metal may include, for example, gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof, and may be composed of one kind of these or may be composed of several kinds of alloys. The average particle diameter (D50) of the metal may be about 4 μm or less, and may be, for example, 10 nm to 4 μm, 10 nm to 2 μm, or 10 nm to 1 μm.

[0218] The carbon material may be, for example, crystalline carbon, non-graphitic carbon, or a combination thereof. The crystalline carbon may be, for example, at least one selected from natural graphite, artificial graphite, mesophase carbon microbeads, and combinations thereof. The non-graphitic carbon may be at least one selected from carbon black, activated carbon, acetylene black, Denka black, Ketjen black, furnace black, graphene, and combinations thereof.

[0219] When the above-described negative electrode coating layer (405) includes both the metal and the carbon material, the mixing ratio of the metal and the carbon material may be, for example, a weight ratio of 1:10 to 1:2, 1:10 to 2:1, 5:1 to 1:1, or 4:1 to 2:1. In this case, the precipitation of lithium metal can be effectively promoted and the characteristics of the all-solid-state battery can be improved. The above-described negative electrode coating layer (405) may include, for example, a carbon material supported with a catalytic metal, or may include a mixture of metal particles and carbon material particles.

[0220] The above cathode coating layer (405) may further include a binder, and the binder may be, for example, a conductive binder. In addition, the above cathode coating layer (405) may further include general additives such as fillers, dispersants, and ionic conductive agents.

[0221] The thickness of the negative electrode coating layer (405) may be, for example, 1 μm to 20 μm, 2 μm to 10 μm, or 3 μm to 7 μm. In addition, the thickness of the negative electrode coating layer (405) may be 50% or less, 20% or less, or 5% or less of the thickness of the positive electrode active material layer. If the thickness of the negative electrode coating layer (405) is too thin, it may be collapsed by the lithium metal layer (404), and if the thickness is too thick, the density of the all-solid-state battery may decrease and the internal resistance may increase.

[0222] The above-described precipitated negative electrode (400') may further include, for example, a thin film on the surface of the current collector, i.e., between the current collector and the negative electrode coating layer. The thin film may include an element capable of forming an alloy with lithium. The element capable of forming an alloy with lithium may be, for example, gold, silver, zinc, tin, indium, silicon, aluminum, bismuth, etc., and may be composed of one type thereof or may be composed of multiple types of alloys. The thin film may further flatten the precipitated form of the lithium metal layer (404) and further improve the characteristics of the all-solid-state battery. The thin film may be formed by, for example, a vacuum deposition method, a sputtering method, a plating method, etc. The thickness of the thin film may be, for example, 1 nm to 800 nm, or 100 nm to 500 nm.

[0223] The lithium metal layer (404) may include lithium metal or a lithium alloy. The lithium alloy may be, for example, a Li-Al alloy, a Li-Sn alloy, a Li-In alloy, a Li-Ag alloy, a Li-Au alloy, a Li-Zn alloy, a Li-Ge alloy, or a Li-Si alloy.

[0224] The thickness of the lithium metal layer (404) may be 1 μm to 500 μm, 1 μm to 200 μm, 1 μm to 100 μm, or 1 μm to 50 μm. If the thickness of the lithium metal layer (404) is too thin, it may be difficult to perform the role of a lithium storage, and if it is too thick, the battery volume may increase and performance may deteriorate.

[0225] When such a precipitation-type cathode is applied, the cathode coating layer (405) can play a role in protecting the lithium metal layer (404) and suppressing the precipitation growth of lithium deadlight. Accordingly, short-circuiting and capacity reduction of the all-solid-state battery can be suppressed, and the life characteristics can be improved.

[0226]

[0227] Hereinafter, examples and comparative examples of the present invention are described. The following examples are merely examples of the present invention, and the present invention is not limited to the following examples.

[0228]

[0229] Synthesis Example 1: Compound represented by Chemical Formula 1-1a

[0230] Compound D (compound represented by Chemical Formula 1-1a) can be obtained by the method of Condition 1 or Condition 2 below.

[0231]

[0232] Condition 1

[0233] (1) Step 1: Synthesis of compound C[2-ethyl-2-(((perfluorobenzoyl)oxy)methyl)propane-1,3-diyl bis(2,3,4,5,6-pentafluorobenzoate)]

[0234] Trimethylolpropane (compound A) (1.3 g, 9.7 mmol) and pentafluorobenzoic acid (compound B) (10 g, 29 mmol) were dissolved in 50 mL of dichloromethane (CH2Cl2) in a 250 mL round-bottomed flask. Then, dicyclohexylcarbodiimide (DCC) (6.0 g, 29 mmol) and 4-dimethylaminopyridinium-p-toluenesulfonic acid salt (DMAP·TsOH) (0.44 g, 1.5 mmol) were added. The reaction mixture was stirred at room temperature for 24 h. After confirming that the reaction was complete through TLC, 1 mL of water was added, stirred for 10 minutes, and the N,N'-dicyclohexyl urea byproduct in the reaction mixture was removed by filtering using filter paper. After adding 100 mL of water to the filtrate, it was extracted three times with dichloromethane (150 mL x 3 times). The extracted organic layer was collected, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator to obtain a white solid. This was recrystallized using dichloromethane and hexane to obtain the desired compound C as a white solid with a yield of 70%.

[0235] (2) Step 2: Synthesis of compound D [2-(((4-azido-2,3,5,6-tetrafluorobenzoyl)oxy)methyl)-2-ethylpropane-1,3-diyl bis(4-azido-2,3,5,6-tetrafluorobenzoate)]

[0236] Compound C (2.5 g, 3.5 mmol) and sodium azide (0.91 g, 14 mmol) were added to a 250 mL brown round-bottom flask. 30 mL of acetone was added dropwise to dissolve Compound C, and 15 mL of distilled water was added dropwise to dissolve sodium azide. The reaction mixture was stirred overnight at 50 °C using a reflux condenser. After the reaction mixture was cooled to room temperature, acetone was removed using a rotary evaporator. Water (20 mL) and dichloromethane (50 mL) were added to the reaction mixture, and the aqueous layer was extracted three times with dichloromethane (50 mL x 3 times). The extracted organic layer was washed again with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator. Afterwards, the concentrated product was recrystallized using dichloromethane and hexane to obtain the desired compound D (compound represented by Chemical Formula 1-1a) as a white solid with a yield of 77%.

[0237] Condition 2

[0238] Trimethylolpropane (compound A) (1.9 g, 14 mmol) and pentafluorobenzoic acid (compound B) (17 g, 49 mmol) were dissolved in 150 mL of toluene in a 250 mL round-bottomed flask. Then, a hafnium catalyst (HfCl4·(THF)2) (0.23 g, 0.49 mmol) was added. A Dean-Stark trap and a reflux condenser were installed in the reaction mixture, and the mixture was stirred under reflux conditions for 2 days. The reaction was carried out while removing the azeotropic mixture of toluene and water generated during the reaction. After the reaction mixture was cooled to room temperature, a NaHCO3 solution was added to the filtrate until it became alkaline, and then it was extracted three times with dichloromethane (150 mL X 3 times). The extracted organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator. The concentrated product was then purified by column chromatography (Hexanes:EtOAc = 4:1, R f =0.63) was purified to obtain the desired compound D (compound represented by Chemical Formula 1-1a) as a white solid with a yield of 66%. The product can be purified by column chromatography or by recrystallization from CH2Cl2 / Hexanes.

[0239] 1 H NMR (CDCl3, 400 MHz): δ 4.40 (s, 6H), 1.67 (q, J = 7.4 Hz, 2H), 0.99 (t, J = 7.4 Hz, 3H); 19 F NMR (CDCl3, 376 MHz): δ -138.24 (m, 6F), -150.5 (m, 6F); LRMS(ESI, positive mode): m / z calculated for [M + Na + ] 808.0533, found 808.1667.

[0240]

[0241] Synthesis Example 2: Compound represented by Chemical Formula 1-1b

[0242]

[0243] Trimethylolpropane (compound A) (0.44 g, 3.3 mmol) and 4-azidobenzoic acid (compound E) (1.78 g, 10.9 mmol) were dissolved in 50 mL of dichloromethane (CH2Cl2) in a 250 mL round-bottomed flask. Then, N,N'-dicyclohexylcarbodiimide (DCC; dicyclohexylcarbodiimide) (2.25 g, 10.9 mmol) and 4-dimethylaminopyridinium-paratoluenesulfonic acid salt (DMAP) were added. . TsOH)(0.16 g, 5 mol%) was added. The reaction mixture was stirred at room temperature for 24 hours. After confirming that the reaction was fully completed through TLC, 1 mL of water was added, stirred for 10 minutes, and the N,N'-dicyclohexyl urea byproduct in the reaction mixture was filtered off using a filter paper. 30 mL of water was added to the filtrate, and the mixture was extracted three times with dichloromethane (30 mL x 3 times). The extracted organic layer was collected, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator to obtain a white solid. This was purified again by column chromatography (Hexanes:EtOAc = 4:1, R f =0.49) was purified to obtain the desired compound F (compound represented by chemical formula 1-1b) as a yellow oil with a yield of 73%. 1 H NMR (CDCl 3, 400 MHz): δ 7.98 (d,J= 8.8 Hz, 6H), δ 7.03 (d,J= 8.8 Hz, 6H), δ 4.47 (s, 6H), δ 1.76 (q,J= 7.6 Hz, 2H), δ 1.06 (t,J= 7.6 Hz, 3H)

[0244]

[0245] Synthesis Example 3: Compound represented by Chemical Formula 1-2a

[0246]

[0247] (1) Synthesis method of compound H [nitrilotris(ethane-2,1-diyl) tris(4-azido-2,3,5,6-tetrafluorobenzoate)]

[0248] In a 100 mL round-bottomed flask, triethanolamine (compound G) (0.25 g, 1.66 mmol) and pentafluorobenzoic acid (compound B) (1.06 g, 4.99 mmol) were dissolved in 30 mL of dichloromethane (CH2Cl2). Then, N,N'-dicyclohexylcarbodiimide (DCC; dicyclohexylcarbodiimide) (1.03 g, 4.99 mmol) and 4-dimethylaminopyridinium-paratoluenesulfonic acid salt (DMAP) were added. . TsOH)(73 mg, 5 mol%) was added. The reaction mixture was stirred at room temperature for 24 hours. After confirming that the reaction was fully completed through TLC, 1 mL of water was added, stirred for 10 minutes, and N,N'-dicyclohexyl urea byproduct was removed by filtering using filter paper. 100 mL of water was added to the filtrate, and extracted three times with dichloromethane (30 mL x 3 times). The extracted organic layer was collected, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator to obtain the desired compound H as a white solid with a yield of 77%. 1 As H NMR determined that the product was superior to the impurities, the next step was performed without purification. 1 H NMR (CDCl 3, 400 MHz): δ 4.44 (t,J= 5.4 Hz, 6H), δ 3.03 (t,J= 5.2 Hz, 6H); 19 F NMR (CDCl 3,376 MHz): δ -138.32 (d,J= 20 Hz, 6H), δ -148.099 (d,J= 22 Hz, 3H), δ -160.27 (d,J= 15.6 Hz, 6H);

[0249] (2) Step 2: Synthesis of compound I [nitrilotris(ethane-2,1-diyl) tris(4-azido-2,3,5,6-tetrafluorobenzoate)]

[0250] Compound H (1.21 g, 1.66 mmol) and sodium azide (0.38 g, 5.8 mmol, 3.5 eq) were added to a 100 mL round-bottomed flask. 20 mL of acetone was added dropwise to dissolve Compound H, and then 10 mL of distilled water was added dropwise to dissolve sodium azide. A stirring magnet was placed in the flask containing the mixture, a reflux condenser was installed, and the mixture was stirred at 50 °C for 24 hours. After the flask containing the mixture was cooled to room temperature, acetone was removed using a rotary evaporator. Dichloromethane (30 mL) and water (10 mL) were added to the reaction mixture, and the aqueous layer was extracted three times with dichloromethane (30 mL x 3 times). The extracted organic layers were collected and washed with saturated brine. The mixture was then dried over anhydrous magnesium sulfate, and the anhydrous magnesium sulfate was removed through a filter. The filtrate was concentrated through a vacuum rotary evaporator to obtain a white solid. The product was purified by column chromatography (Hexanes:EtOAc = 4:1, R f :0.38) was purified to obtain the desired compound I (compound represented by chemical formula 1-2a) as a white solid with a yield of 61%.

[0251] 1 H NMR (400 MHz, CDCl3): δ 4.43 (t,J= 5.6 Hz, 6H), δ 3.03 (t,J= 5.6 Hz, 6H); 19F NMR (375 MHz, CDCl3): δ -138.76 (d,J= 9.6 Hz, 6H), δ -150.95 (d,J= 9.6 Hz, 6H)

[0252]

[0253] Synthesis Example 4: Compound represented by Chemical Formula 1-3a

[0254]

[0255]

[0256] In a 100 mL brown round-bottomed flask, 4-azido-2,3,5,6-tetrafluorobenzoic acid (compound J) (0.9 g, 3.8 mmol) and bis(2-hydroxyethyl)disulfide (compound K) (0.30 g, 1.9 mmol) were dissolved in 10 mL of dichloromethane (CH2Cl2). Then, dicyclohexylcarbodiimide (DCC) (0.79 g, 3.8 mmol) and dimethylaminopyridinium-p-toluenesulfonate (DMAP·TsOH) (56 mg, 0.19 mmol) were added. The reaction mixture was stirred at room temperature for 48 h. After confirming that the reaction was fully completed through TLC, 0.1 mL of water was added and stirred for 10 minutes, and the N,N'-dicyclohexyl urea byproduct in the reaction mixture was filtered off using a filter paper. 10 mL of water was added to the filtrate, and the mixture was extracted three times with dichloromethane (15 mL x 3 times). The extracted organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator. The concentrated product was then purified by column chromatography (Hexanes: EtOAc = 4:1, , R f =0.55) and purified to obtain the desired compound L (compound represented by chemical formula 1-3a) as a white solid with a yield of 73%.

[0257] 1H NMR (CDCl3, 400 MHz): δ 4.63 (t, J = 6.6 Hz, 4H), 3.66 (t, J = 6.6 Hz, 4H); 19 F NMR (CDCl3, 376 MHz): δ -138.24 (m, 6F), -150.77 (m, 6F).

[0258]

[0259] Synthesis Example 5: Compound represented by Chemical Formula 1-4a

[0260]

[0261] In a 100 mL brown round-bottomed flask, 4-azido-2,3,5,6-tetrafluorobenzoic acid (compound J) (0.80 g, 3.4 mmol) and n-octanol (compound M) (0.44 g, 3.4 mmol) were dissolved in 5 mL of dichloromethane (CH2Cl2). Then, dicyclohexylcarbodiimide (DCC; dicyclohexylcarbodiimide) (0.70 g, 3.4 mmol) and 4-dimethylaminopyridinium-p-toluenesulfonic acid salt (DMAP·TsOH) (21 mg, 0.17 mmol) were added. The reaction mixture was stirred at room temperature for 48 h. After confirming that the reaction was fully completed through TLC, 0.1 mL of water was added and stirred for 10 minutes, and the N,N'-dicyclohexyl urea byproduct in the reaction mixture was filtered off using a filter paper. 10 mL of water was added to the filtrate, and the mixture was extracted three times with dichloromethane (15 mL x 3 times). The extracted organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator. The concentrated product was then purified by column chromatography (Hexanes: EtOAc = 10:1, R f =0.55) was purified to obtain the desired compound N (compound represented by chemical formula 1-4a) as a light yellow liquid with a yield of 78%.

[0262] 1H NMR (CDCl3, 400 MHz): δ 4.36 (t, J = 6.6 Hz, 2H), 1.74 (t, J = 7.6 Hz, 2H), 1.34 (m, 10H), 0.88 (t, J = 5.9 Hz, 2H).; 19 F NMR (CDCl3, 376 MHz): δ -138.84 (m, 6F), -150.97 (m, 6F).

[0263]

[0264] Comparative Synthesis Example 1: Compound represented by Chemical Formula 1-1c

[0265] [Chemical Formula 1-1c]

[0266]

[0267] Trimethylolpropane (compound A) (1.3 g, 9.7 mmol) and pentafluorobenzoic acid (compound B) (10 g, 29 mmol) were dissolved in 50 mL of dichloromethane (CH2Cl2) in a 250 mL round-bottomed flask. Then, dicyclohexylcarbodiimide (DCC) (6.0 g, 29 mmol) and 4-dimethylaminopyridinium-p-toluenesulfonic acid salt (DMAP·TsOH) (0.44 g, 1.5 mmol) were added. The reaction mixture was stirred at room temperature for 24 h. After confirming that the reaction was complete through TLC, 1 mL of water was added, stirred for 10 minutes, and the N,N'-dicyclohexyl urea byproduct in the reaction mixture was removed by filtering using filter paper. After adding 100 mL of water to the filtrate, it was extracted three times with dichloromethane (150 mL x 3 times). The extracted organic layer was collected, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated using a vacuum rotary evaporator to obtain a white solid. This was recrystallized using dichloromethane and hexane, and the desired compound C (compound represented by Chemical Formula 1-1c) was obtained as a white solid at a yield of 70%.

[0268]

[0269] Example 1

[0270] (1) Manufacturing of solid electrolyte layer

[0271] An acrylic binder (SX-A334, Zeon) is dissolved in an isobutyryl isobutyrate (octyl acetate, OA) solvent. In a weight ratio of 95:5, an argyrodite-type solid electrolyte Li6PS5Cl (D50=3㎛) and the additive of Synthesis Example 1 (a compound represented by Chemical Formula 1-1a) are added to the binder solution, and the viscosity is adjusted to an appropriate value by stirring in a sinky mixer. After adjusting the viscosity, 2 mm zirconia balls are added and stirred again in a sinky mixer to prepare a slurry. The slurry contains 93.1 wt% of the solid electrolyte, 4.9 wt% of the additive of Synthesis Example 1, and 2 wt% of the binder. The slurry is applied on a release PET film using a bar coater and dried at room temperature to prepare a solid electrolyte layer.

[0272] (2) Manufacturing of the anode

[0273] LiNi 0.9 Co 0.05 Mn 0.05 85 wt% of O2 positive electrode active material, 13.5 wt% of lithium argyrodite-type solid electrolyte Li6PS5Cl, 1.0 wt% of polyvinylidene fluoride binder, and 0.5 wt% of carbon nanotube conductive agent are prepared, and added to a dispersion medium in which octyl acetate (OA) and pentyl propionate (PPP) are mixed in a weight ratio of 1:1. This is placed in a thinky mixer, 2 mm zirconia balls are added, and stirred to prepare a positive electrode composition. The content of the dispersion medium is 30 parts by weight based on 100 parts by weight of solid content. The solid content represents the sum of the positive electrode active material, solid electrolyte, binder, and conductive agent.

[0274] The prepared positive electrode composition is coated on a positive electrode current collector using a bar coater, and dried in a convection oven at 80°C for 10 minutes, thereby manufacturing a positive electrode in which a positive electrode active material layer is formed on the current collector.

[0275] (3) Manufacturing of cathode

[0276] A catalyst is prepared by mixing carbon black having a primary particle size (D50) of about 30 nm and silver (Ag) having an average particle size (D50) of about 60 nm in a weight ratio of 3:1, and 0.25 g of the catalyst is added to 2 g of an NMP solution containing 7 wt% of polyvinylidene fluoride binder and mixed to prepare a cathode coating layer composition. This is applied to a nickel foil current collector using a bar coater and vacuum-dried to prepare a deposition-type cathode in which a cathode coating layer is formed on the current collector.

[0277] (4) Manufacturing of all-solid-state batteries

[0278] The positive electrode, negative electrode, and solid electrolyte layer are cut, and the solid electrolyte layer is laminated on the positive electrode, and then the negative electrode is laminated on top of that. This is sealed in a pouch shape and isostatically pressed (WIP) at a high temperature of 85°C and 500 MPa for 30 minutes to manufacture an all-solid-state battery. In a pressurized state, the positive electrode active material layer has a thickness of approximately 100 μm, the negative electrode coating layer has a thickness of approximately 7 μm, and the solid electrolyte layer has a thickness of approximately 60 μm.

[0279]

[0280] Example 2

[0281] A solid electrolyte layer and an all-solid-state battery are manufactured in the same manner as Example 1, except that the additive of Synthesis Example 2 (a compound represented by Chemical Formula 1-1b) is used instead of the additive of Synthesis Example 1 (a compound represented by Chemical Formula 1-1a).

[0282]

[0283] Example 3

[0284] A solid electrolyte layer and an all-solid-state battery are manufactured in the same manner as Example 1, except that the additive of Synthesis Example 3 (a compound represented by Chemical Formula 1-2a) is used instead of the additive of Synthesis Example 1 (a compound represented by Chemical Formula 1-1a).

[0285]

[0286] Example 4

[0287] A solid electrolyte layer and an all-solid-state battery are manufactured in the same manner as Example 1, except that the additive of Synthesis Example 4 (a compound represented by Chemical Formula 1-3a) is used instead of the additive of Synthesis Example 1 (a compound represented by Chemical Formula 1-1a).

[0288]

[0289] Example 5

[0290] A solid electrolyte layer and an all-solid-state battery are manufactured in the same manner as Example 1, except that the additive of Synthesis Example 5 (a compound represented by Chemical Formula 1-4a) is used instead of the additive of Synthesis Example 1 (a compound represented by Chemical Formula 1-1a).

[0291]

[0292] Example 6

[0293] When manufacturing a solid electrolyte layer, the argyrodite-type solid electrolyte Li6PS5Cl (D50=3㎛) and the additive of Synthesis Example 1 are added at a weight ratio of 97:3 so that the slurry contains 95.06 wt% of the solid electrolyte, 2.94 wt% of the additive of Synthesis Example 1, and 2 wt% of the binder. Except for this, an all-solid-state battery is manufactured in the same manner as Example 1.

[0294]

[0295] Example 7

[0296] When manufacturing a solid electrolyte layer, the argyrodite-type solid electrolyte Li6PS5Cl (D50=3㎛) and the additive of Synthesis Example 1 are added at a weight ratio of 90:10 so that the slurry contains 88.2 wt% of the solid electrolyte, 9.8 wt% of the additive of Synthesis Example 1, and 2 wt% of the binder. Except for this, an all-solid-state battery is manufactured in the same manner as Example 1.

[0297]

[0298] Comparative Example 1 (Ref.)

[0299] When manufacturing a solid electrolyte layer, only argyrodite-type solid electrolyte Li6PS5Cl (D50=3㎛) is added so that the slurry contains 98 wt% of the solid electrolyte and 2 wt% of the binder. Except for this, an all-solid-state battery is manufactured in the same manner as Example 1.

[0300]

[0301] Evaluation Example 1: Thermogravimetric Analysis (TGA)

[0302] For each additive of Synthesis Examples 1 to 4 and Comparative Synthesis Example 1, thermogravimetric analysis was performed in a temperature range of 30 to 300°C, and the results are shown in Fig. 3.

[0303] Thermogravimetric analysis was performed using a TGA8000 from PerkinElmer, taking approximately 10 mg of the additive.

[0304] Figure 3 is a TGA thermal analysis diagram of the additive of Synthesis Example 1 (a compound represented by Chemical Formula 1-1a). According to Figure 3, the compound represented by Chemical Formula 1-1a exhibits a weight loss of approximately 11% from about 140°C to 230°C.

[0305] Figure 4 is a TGA thermal analysis diagram of the additive of Synthesis Example 2 (a compound represented by Chemical Formula 1-1b). According to Figure 4, the compound represented by Chemical Formula 1-1b exhibits a weight loss of approximately 15% from about 140°C to 220°C.

[0306] Figure 5 is a TGA thermal analysis diagram of the additive of Synthesis Example 3 (a compound represented by Chemical Formula 1-2a). According to Figure 5, the compound represented by Chemical Formula 1-2a exhibits a weight loss of approximately 22% from about 140°C to 220°C.

[0307] Figure 6 is a TGA thermal analysis diagram of the additive of Synthesis Example 4 (a compound represented by Chemical Formula 1-3a). According to Figure 6, the compound represented by Chemical Formula 1-3a exhibits a weight loss of approximately 11% from about 140°C to 185°C.

[0308] When analyzing the TGA for each additive in Synthesis Examples 1 to 4, the weight loss after nitrogen gas generation was similar to the theoretically calculated amount.

[0309] From this, it can be seen that the azide group (-N3) in each of the additives of Synthesis Examples 1 to 4 decomposes at a high temperature of about 140°C or higher to generate nitrogen (N2) and is converted into a nitrene group (-N).

[0310]

[0311] Evaluation Example 2: Differential Scanning Calorimetry (DSC)

[0312] For each of the all-solid-state batteries of Examples 1 to 5 and Comparative Example 1, analysis was conducted using differential scanning calorimetry (DSC) in the temperature range of 40 to 200°C.

[0313] The solid-state battery was charged to 4.20 V, and a DSC sample was prepared in an Ar atmosphere glove box using the following procedure. A single cell was removed from the laminated outer case and drilled to φ 2.5 mm using a mold. It was placed in a SUS sample pan, a lid was set, and the opening was sealed by bonding with a press. The DSC sample thus prepared was measured using a DSC measuring device (DSC7000X) manufactured by Hitachi High-Tech Sciences at a temperature range of 40 to 200°C.

[0314] Figure 7 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 1 (compound represented by Chemical Formula 1-1a) was applied.

[0315] Figure 8 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 2 (compound represented by Chemical Formula 1-1b) was applied.

[0316] Figure 9 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 3 (compound represented by Chemical Formula 1-2a) was applied.

[0317] Figure 10 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 4 (compound represented by Chemical Formula 1-3a) was applied.

[0318] Figure 11 is a DSC analysis diagram for the all-solid-state battery of Example 1 to which the additive of Synthesis Example 5 (compound represented by Chemical Formula 1-4a) was applied.

[0319] In each of the all-solid-state batteries of Examples 1 to 5, it can be seen that the azide group (azide, -N3) in each additive is decomposed at the high temperature of the first cycle to generate nitrogen (N2), and the azide group (azide, -N3) is converted to a nitrene group (nitrene, -N) at a high temperature of 140°C or higher.

[0320]

[0321] Evaluation Example 3: Lithium ion conductivity analysis

[0322] Each solid electrolyte layer of Examples 1 to 5 and Comparative Example 1 was heated at 180°C for 30 minutes, and the change in ionic conductivity before and after heating was measured, and the results are shown in Table 1 below.

[0323] Ionic conductivity is measured by electrochemical impedance spectroscopy (EIS), which is performed at an amplitude of approximately 10 mV, a frequency of 0.1 MHz to 0.1 to 0.05 Hz, in air at 25°C.

[0324] Ionic Conductivity (mS / cm) Ionic Conductivity Retention Rate (%) Less than 180 ℃ More than 180 ℃ Example 10.68--Example 20.67--Example 30.68--Example 40.69--Example 50.67--Comparative Example 10.700.6795.7

[0325] (In the above Table 1, '-' means that the ionic conductivity is so low that it cannot be measured.) According to the above Table 1, it can be seen that the additive of one embodiment represented by Examples 1 to 5 has the effect of rapidly reducing the ionic conductivity at a high temperature of 180°C or higher, thereby shutting down the lithium secondary battery at a temperature lower than the ignition temperature.

[0326] While the preferred embodiments have been described in detail, the scope of the present invention is not limited thereto. Furthermore, it should be understood that various modifications and improvements made by those skilled in the art utilizing the basic concepts defined in the claims are also within the scope of the present invention.

[0327]

[0328] [Explanation of symbols]

[0329] 100: All-solid-state battery 200: Cathode

[0330] 201: Cathode current collector 203: Cathode active material layer

[0331] 300: solid electrolyte layer 400: cathode

[0332] 401: Negative current collector 403: Negative active material layer

[0333] 400': Precipitation type cathode 404: Lithium metal layer

[0334] 405: Cathode coating layer 500: Elastic layer

Claims

1. Additive for lithium secondary batteries represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, X1 is the same or different and is a hydrogen atom or a halogen atom; A is a substituent represented by the following chemical formula 2, a substituent represented by the following chemical formula 3, a substituent represented by the following chemical formula 4, a substituent represented by the following chemical formula 5, or a substituted or unsubstituted C1 to C20 alkyl group; [Chemical Formula 2] In the above chemical formula 2, Z1 is a carbon atom or a silicon atom, L1 is the same or different and is a single bond or a substituted or unsubstituted C1 to C20 alkylene group; R1 is the same or different and is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, or a substituent represented by the following chemical formula 5; [Chemical Formula 3] In the above chemical formula 3, Z2 is a nitrogen atom or a phosphorus atom; L2 is the same or different and is a single bond or a substituted or unsubstituted C1 to C20 alkylene group; R2 is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, or a substituent represented by the following chemical formula 5; [Chemical Formula 4] L3 is a single bond, a disulfide bond, a substituted or unsubstituted C1 to C20 alkylene group, or a combination thereof; R3 is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, or a substituent represented by the following chemical formula 5; [Chemical Formula 5] In the above chemical formula 5, X2 is the same or different and is a hydrogen atom or a halogen atom.

2. In paragraph 1, The above chemical formula 1 is an additive for a lithium secondary battery represented by any one of the following chemical formulas 1-1 to 1-4: [Chemical Formula 1-1] [Chemical Formula 1-2] [Chemical Formula 1-3] [Chemical Formula 1-4] In the above chemical formulas 1-1 to 1-4, Z1 is a carbon atom or a silicon atom; Z2 is a nitrogen atom or a phosphorus atom; X1 is the same or different and is a hydrogen atom or a halogen atom; X2 is the same or different and is a hydrogen atom or a halogen atom; L1 is the same or different and is a single bond or a substituted or unsubstituted C1 to C20 alkylene group; L2 is the same or different and is a single bond or a substituted or unsubstituted C1 to C20 alkylene group; L3 is the same or different and is a single bond, a disulfide bond, a substituted or unsubstituted C1 to C20 alkylene group, or a combination thereof; R4 is a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group.

3. In paragraph 1, X1 is an additive for lithium secondary batteries, which is either all hydrogen atoms or all halogen atoms.

4. In paragraph 1, Z1 is an additive for lithium secondary batteries that contains carbon atoms.

5. In paragraph 1, L1 is an additive for lithium secondary batteries that contains all methylene groups.

6. In paragraph 1, L2 is an additive for lithium secondary batteries that is all ethylene-based.

7. In paragraph 1, Z2 is a nitrogen atom additive for lithium secondary batteries.

8. In paragraph 1, L3 is a single bond; or a combination of a disulfide bond and an ethylene group. An additive for lithium secondary batteries.

9. In paragraph 1, X2 is an additive for lithium secondary batteries that is all hydrogen atoms or all halogen atoms.

10. In paragraph 1, The above additive is an additive for a lithium secondary battery selected from the group represented below: [Chemical Formula 1-1a] [Chemical Formula 1-1b] [Chemical Formula 1-2a] [Chemical Formula 1-3a] [Chemical Formula 1-4a] . .

11. An electrolyte layer for a lithium secondary battery comprising an additive according to any one of claims 1 to 10.

12. In paragraph 11, An electrolyte layer for a lithium secondary battery, wherein the additive is included in an amount of 0.01 to 10 wt% out of a total amount of 100 wt% of the electrolyte layer.

13. In paragraph 11, An electrolyte layer for a lithium secondary battery, wherein the electrolyte layer further comprises a solid electrolyte.

14. In paragraph 13, A lithium secondary battery wherein the weight ratio of the solid electrolyte:additive in the electrolyte layer is 99.9:0.01 to 90:

10.

15. A positive electrode for a lithium secondary battery comprising an additive according to any one of claims 1 to 10.

16. A negative electrode for a lithium secondary battery comprising an additive according to any one of claims 1 to 10.

17. Bipolar; cathode; and Including an electrolyte layer disposed between the anode and the cathode, At least one layer of the positive electrode, the negative electrode, and the electrolyte layer comprises an additive according to any one of claims 1 to 10. Lithium secondary battery.

18. In paragraph 17, The above lithium secondary battery is a lithium secondary battery that is an all-solid-state battery, a semi-solid-state battery, a lithium metal battery, or a lithium ion battery.

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