A negative electrode coating layer and all-solid-state battery containing the same

Abstract

The present invention comprises first amorphous carbon and second amorphous carbon, and the particle size analysis results obtained by a particle size analyzer (Mastersizer 3000), D 50 / D 10 The present invention relates to a non-negative electrode coating layer and an all-solid-state battery containing the same, characterized in that the value is in the range of 3.5 to 10. According to the present invention, it is possible to provide a non-negative electrode coating layer and an all-solid-state battery containing the same with improved performance, stability, and / or life characteristics.

Description

[Technical Field]

[0001] This application claims priority under Republic of Korea Patent Application No. 2023-0134367 dated October 10, 2023, and all content disclosed in the documents of the said Republic of Korea Patent Application is included as part of this specification. The present invention relates to a negative electrode coating layer and an all-solid-state battery including the same. [Background technology]

[0002] Recently, industrial demands have led to the proposal of all-solid-state batteries with high energy density and stability, and efforts are continuing to further improve these characteristics. As one example, methods using lithium as the negative electrode active material are being studied to increase the energy density of all-solid-state batteries.

[0003] Methods for using lithium as a negative electrode active material include using lithium or a lithium alloy as a negative electrode active material layer during the battery manufacturing process, or not forming a separate negative electrode active material layer on the negative electrode current collector during the battery manufacturing process, but instead forming a lithium layer during the charging process.

[0004] However, when lithium is used as the negative electrode active material, lithium (metallic lithium) is deposited on the negative electrode side during charging. As the charge-discharge process is repeated, lithium dendrites grow through the gaps in the solid electrolyte layer, which can cause a short circuit in the battery or reduce its capacity, thus posing a problem.

[0005] Therefore, in order to put into practical use a method that uses lithium as a negative electrode active material, it is necessary to improve the aforementioned problems. [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention is for solving the above problems, and an object thereof is to provide a non-aqueous negative electrode coating layer with improved performance, stability, and / or life characteristics, and a all-solid-state battery including the same.

Means for Solving the Problems

[0007] One aspect of the present invention relates to a non-aqueous negative electrode coating layer including first amorphous carbon and second amorphous carbon, wherein the result of particle size analysis by a particle size analyzer (Mastersizer 3000), D 50 / D 10 is within the range of 3.5 to 10.

[0008] In one embodiment, D of the non-aqueous negative electrode coating layer 10 may be 0.06 μm or less.

[0009] In one embodiment, D of the non-aqueous negative electrode coating layer 10 may be 0.03 μm or more.

[0010] In one embodiment, the present invention may relate to a non-aqueous negative electrode coating layer, wherein a graph of the result of particle size analysis by a particle size analyzer (Mastersizer 3000) with the particle size (size) on the x-axis (μm) and the volume density on the y-axis (%) has two peaks at 0.1 μm to 0.5 μm and satisfies the following formula 1:

[0011] [Formula 1] 1.0 ≦ (x2 - x1) / x1 * (y1 / y2) ≦ 2.0

[0012] In the above formula, x1 and x2 are the x-axis values of the two peaks respectively, x1 < x2, y1 is the y-axis value of the x1 peak, and y2 may be the y-axis value of the x2 peak.

[0013] In one embodiment, the ratio of the average particle size of the primary particles of the first amorphous carbon to the average particle size of the primary particles of the second amorphous carbon may be in the range of 1.1 to 3.3, and the weight ratio of the first amorphous carbon to the second amorphous carbon may be in the range of 5 to 20.

[0014] In one embodiment, the average particle size of the primary particles of the first amorphous carbon may be in the range of 30 nm to 50 nm.

[0015] In one embodiment, the average particle size of the primary particles of the second amorphous carbon may be in the range of 15 nm to 25 nm.

[0016] In one embodiment, the specific surface area of ​​the first amorphous carbon is 10 to 100 m². 2 It may be within the range of / g.

[0017] In one embodiment, the specific surface area of ​​the second amorphous carbon is 110 to 230 m². 2 It may be within the range of / g.

[0018] In one embodiment, the first amorphous carbon and the second amorphous carbon may each be independently selected from the group consisting of carbon black, acetylene black, furnace black, Ketjen black, and graphene.

[0019] In one embodiment, the negative electrode coating layer of the present invention may further include a metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium.

[0020] In one embodiment, the metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium may be one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).

[0021] In one embodiment, the weight ratio between the total of first amorphous carbon and second amorphous carbon to the metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium may be in the range of 1 to 10.

[0022] In one embodiment, the non-negative electrode coating layer of the present invention may further include a binder.

[0023] In one embodiment, the weight ratio between the binder and the total of the first amorphous carbon, the second amorphous carbon, and the metals, quasimetallic elements, or combinations thereof that form alloys or compounds with lithium may be in the range of 5 to 50.

[0024] Another aspect of the present invention includes a positive electrode, a solid electrolyte layer, a non-negative electrode coating layer, and a negative electrode, wherein the non-negative electrode coating layer comprises first amorphous carbon and second amorphous carbon, and the particle size analysis results obtained by a particle size analyzer (Mastersizer 3000), D 50 / D 10 This invention relates to an all-solid-state battery characterized in that the value is within the range of 3.5 to 10.

[0025] In one embodiment, the solid electrolyte layer may contain a sulfide-based solid electrolyte.

[0026] In one example, the porosity of the non-negative electrode coating layer may be in the range of 50 to 80%. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a non-negative electrode coating layer with improved performance, stability, and / or lifespan characteristics, and an all-solid-state battery containing the same. [Brief explanation of the drawing]

[0028] [Figure 1] This graph illustrates the evaluation results of the life characteristics (capacity retention rate related to cycles) of all-solid-state batteries in the examples and comparative examples. [Figure 2] This graph shows the particle size analysis results for the non-negative electrode coating layer slurry of Example 1. [Figure 3] This graph shows the particle size analysis results for the non-negative electrode coating layer slurry of Example 2. [Figure 4] This graph shows the particle size analysis results for the non-negative electrode coating layer slurry of Comparative Example 1. [Figure 5] This graph shows the particle size analysis results for the non-negative electrode coating layer slurry of Comparative Example 2. [Figure 6] This graph shows the particle size analysis results for the non-negative electrode coating layer slurry of Comparative Example 3. [Figure 7] This graph shows the particle size analysis results for the non-negative electrode coating layer slurry of Comparative Example 4. [Figure 8] This graph shows the particle size analysis results for the non-negative electrode coating layer slurry of Comparative Example 5. [Modes for carrying out the invention]

[0029] The terms and words used in this specification and in the claims should not be construed to be limited to their ordinary or dictionary meanings, but rather to be construed in a sense and concept consistent with the technical idea of ​​the present invention, based on the principle that inventors can appropriately define the concepts of terms in order to best describe their inventions.

[0030] Therefore, the configurations of the embodiments described herein represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the invention. It should be understood that, at the time of filing, there may be a variety of equivalents and modifications that can be substituted for these.

[0031] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0032] In this specification, when a part is said to "contain" a component, this means, unless otherwise stated, that it may contain other components rather than excluding them. For example, a composition containing compound A may contain other compounds other than A. However, the term "contains" also encompasses, in its particular embodiment, the more restrictive meanings of "essentially / essentially composed of" and "composed of," for example, a "composition containing compound A" may also be (essentially / essentially) composed of compound A.

[0033] In this regard, as described herein, terms such as “equipped with” or “possess” are intended to specify the presence of implemented features, figures, stages, components, or combinations thereof, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more different features, figures, stages, components, or combinations thereof.

[0034] In this specification, when any member is said to be "on" any other member, this includes not only cases where such member is in contact with another member, but also cases where there are other members or materials between the two members.

[0035] Where, in this specification, a quantity, concentration, or other value or parameter is given by listing a range, preferred range, preferred upper limit, and preferred lower limit, it should be understood that this specifically discloses all ranges that can be formed by any pair of any upper range limits or preferred values ​​and any lower range limits or preferred values, regardless of whether the range is disclosed separately. Where, in this specification, a range of numerical values ​​is referred to, unless otherwise stated, and unless there are limiting terms such as greater than or less than, the range is intended to include its endpoint and all integers and fractions within that range. The scope of the present invention is intended not to be limited to specific values ​​referred to when defining a range.

[0036] In this specification, if the measurement temperature affects the physical properties mentioned, those properties are measured at room temperature unless otherwise specified. The term "room temperature" refers to the natural temperature without heating or deheating, and may mean, for example, any temperature within the range of approximately 10°C to 30°C, or approximately 23°C or 25°C. Furthermore, unless otherwise specified, the unit of temperature in this specification is °C.

[0037] Furthermore, in the case of any physical properties mentioned herein where the measurement pressure affects the property in question, unless otherwise specified, the physical properties are measured at normal pressure, i.e., atmospheric pressure (approximately 1 atmosphere).

[0038] In this specification, "all-solid-state battery" may mean an all-solid-state rechargeable battery, and may also be referred to as a cell, rechargeable battery, or battery, etc.

[0039] In this specification, "negative electrode coating layer" refers to a coating layer formed between the negative electrode current collector and the solid electrolyte layer in an all-solid-state battery in which lithium is absorbed into the negative electrode coating layer during charging, lithium is deposited between the negative electrode current collector and the negative electrode coating layer after the charging capacity of the negative electrode coating layer is exceeded, forming a metal layer, and during discharge, the lithium in the negative electrode coating layer and the lithium metal layer is ionized and moves to the positive electrode side, and its structure and operating mechanism may differ from that of a conventional negative electrode active material layer. The negative electrode coating layer can cover the lithium metal layer formed on the negative electrode current collector during the charging process and act as a protective layer for the lithium metal layer, suppressing the deposition and growth of lithium dendrites, thereby suppressing short circuits and capacity degradation of the all-solid-state battery and improving performance.

[0040] A first aspect of the present invention relates to a non-negative electrode coating layer.

[0041] The non-anode coating layer of the present invention can include, for example, a first amorphous carbon and a second amorphous carbon. In the present specification, the terms "first amorphous carbon" and "second amorphous carbon" are merely for distinguishing amorphous carbons with different characteristics, and do not necessarily mean different types. The first amorphous carbon and the second amorphous carbon can be of the same or different types. When two types of amorphous carbons with different characteristics are included in the non-anode coating layer, for example, the amorphous carbon with a relatively larger average particle size of primary particles and / or average particle size of secondary particles is referred to as the first amorphous carbon, and the amorphous carbon with a relatively smaller average particle size of primary particles and / or average particle size of secondary particles can be referred to as the second amorphous carbon. In other examples, the amorphous carbon with a relatively smaller specific surface area is referred to as the first amorphous carbon, and the amorphous carbon with a relatively larger specific surface area can be referred to as the second amorphous carbon.

[0042] The non-anode coating layer has a D 50 / D 10 which can be, for example, in the range of 3.5 to 10. The particle size analysis by the particle size analyzer (Mastersizer 3000) can be performed by the method according to the following evaluation example. The D 50 / D 10 of the non-anode coating layer can be, in other examples, 4.0 or more, 4.5 or more, 5.0 or more, or 5.5 or more, or 9.5 or less, 8.0 or less, 7.5 or less, 7.0 or less, 6.5 or less, or 6.0 or less. By controlling the particle size characteristics of the non-anode coating layer as described above, the present invention can improve the dispersibility of the non-anode coating layer slurry and provide an all-solid-state battery having excellent life characteristics.

[0043] The non-anode coating layer of the present invention can be characterized in that D 10 is 0.06 μm or less. The D 10 can be, in other examples, 0.055 μm or less or 0.05 μm or less. The non-anode coating layer of the present invention has a D 10It may be characterized in that it is 0.03 μm or more. The said D 10 In other examples, D may be 0.031 μm or more, 0.032 μm or more, 0.033 μm or more, 0.034 μm or more, 0.035 μm or more, 0.036 μm or more, 0.037 μm or more, 0.038 μm or more, 0.039 μm or more, 0.040 μm or more, 0.041 μm or more, 0.042 μm or more, 0.043 μm or more, 0.044 μm or more, 0.045 μm or more, 0.046 μm or more, or 0.047 μm or more.

[0044] The D of the non - negative electrode coating layer 10 If it is too large or too small, the dispersibility of the non - negative electrode coating layer slurry may be low, which is considered to have a negative impact on the life characteristics and stability of the all - solid - state battery. Therefore, it is important to control the particle size characteristics of the non - negative electrode coating layer as described above, and the life characteristics can be further improved by additionally controlling the characteristics described below.

[0045] The present invention may relate to a non - negative electrode coating layer, characterized in that, for example, a graph of the particle size analysis result by a particle size analyzer (Mastersizer 3000) with the particle size (size) on the x - axis (μm) and the volume density on the y - axis (%) has two peaks at 0.1 μm to 0.5 μm and satisfies the following mathematical formula 1:

[0046] [Mathematical formula 1] 1.0≦{(x2 - x1) / x1}*(y1 / y2)≦2.0

[0047] [[ID=2​​​​​​ In other examples, {(x2-x1) / x1}*(y1 / y2) may be 1.1 or greater, 1.2 or greater, or 1.3 or greater, or 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, or 1.4 or less.

[0050] The negative electrode coating layer of the present invention has two peaks in the 0.1 μm to 0.5 μm range, as described above, and satisfies the range of Equation 1, thereby further improving the lifespan and stability of all-solid-state batteries. Although the exact reason has not been determined, it is thought that in the case of a negative electrode coating layer satisfying the above configuration, the dispersibility between amorphous carbon and / or metals, binders, etc., contained in the slurry is improved, improving lithium ion mobility while also increasing the reaction between lithium and metals, etc., that form alloys or compounds with lithium. Such excellent lifespan and stability can be further improved through the configuration described later.

[0051] The (y1 / y2) can be, for example, within the range of 0.62 to 0.92. In other examples, the (y1 / y2) can be 0.63 or more, 0.64 or more, 0.65 or more, 0.66 or more, 0.67 or more, 0.68 or more, 0.69 or more, 0.70 or more, 0.71 or more, 0.72 or more, 0.73 or more, 0.74 or more, 0.75 or more, 0.76 or more, 0.77 or more, or 0.78 or more, or 0.91 or less, 0.90 or less, 0.89 or less, 0.88 or less, 0.87 or less, 0.86 or less, 0.85 or less, 0.84 or less, 0.83 or less, or 0.82 or less.

[0052] The (x2-x1) / x1 can be, for example, within the range of 1.5 to 2.5. In other examples, the (x2-x1) / x1 can be 1.55 or greater, 1.60 or greater, 1.65 or greater, 1.70 or greater, or 1.75 or greater, or 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, 2.0 or less, 1.9 or less, or 1.8 or less.

[0053] The present invention relates to a non-negative electrode coating layer in which the ratio of the average particle size of the primary particles of the first amorphous carbon to the average particle size of the primary particles of the second amorphous carbon may be in the range of 1.1 to 3.3, and the weight ratio of the first amorphous carbon to the second amorphous carbon may be in the range of 5 to 20. The present invention makes it possible to increase the amount of amorphous carbon that is lithiumized through a non-negative electrode coating layer containing first and second amorphous carbon in a predetermined weight ratio, wherein the ratio of the average particle size of the primary particles is within the range described above. Furthermore, it is possible to facilitate the reaction between lithium and metals, quasimetallic elements, or combinations thereof that form alloys or compounds with lithium, as described later, thereby further improving the safety and life characteristics of all-solid-state batteries.

[0054] The ratio of the average particle size of the primary particles of the first amorphous carbon to the average particle size of the primary particles of the second amorphous carbon may, in other examples, be 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, or 2.0 or more, or 3.2 or less, 3.1 or less, 3.0 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, or 2.1 or less. The average particle size of the amorphous carbon primary and / or secondary particles may be measured by the method described in the evaluation example below.

[0055] The weight ratio of the first amorphous carbon to the second amorphous carbon may be 6 or more, 7 or more, or 8 or more, or 18 or less, 16 or less, 14 or less, 12 or less, or 10 or less, in other examples.

[0056] The negative electrode coating layer of the present invention, by containing first and second amorphous carbon in a predetermined weight ratio, with the ratio of the average particle size of the primary particles controlled as described above, can control the porosity of the negative electrode coating layer to a range described later, thereby preventing cracks from occurring in the negative electrode during charging of the all-solid-state battery and improving the battery's lifespan characteristics. Such effects can be further enhanced by controlling additional configurations described later.

[0057] The average particle size of the primary particles of the first amorphous carbon may be, for example, in the range of 30 nm to 50 nm. In this specification, the average particle size of the primary particles of amorphous carbon can be measured by the method described in the evaluation example below. In other examples, the average particle size of the primary particles of the first amorphous carbon may be 31 nm or more, 32 nm or more, 33 nm or more, 34 nm or more, 35 nm or more, 36 nm or more, 37 nm or more, 38 nm or more, 39 nm or more, or 40 nm or more, or 49 nm or less, 48 ​​nm or less, 47 nm or less, 46 nm or less, 45 nm or less, 44 nm or less, 43 nm or less, or 42 nm or less.

[0058] The average particle size of the primary particles of the second amorphous carbon may be, for example, in the range of 15 nm to 25 nm. In other examples, the average particle size of the primary particles of the second amorphous carbon may be 16 nm or more, 17 nm or more, 18 nm or more, or 19 nm or more, or 24 nm or less, 23 nm or less, 22 nm or less, or 21 nm or less.

[0059] The present invention increases the amount of amorphous carbon lithified per unit area while improving the reaction between lithium and metals, quasimetallic elements, or combinations thereof that form alloys or compounds with lithium, as described later, by controlling the average particle size of the primary particles of the first amorphous carbon and / or the second amorphous carbon to the range described above, thereby reducing the amount of irreversible lithium per unit area. This effect can be further enhanced by controlling the specific surface area of ​​the first and second amorphous carbon, as described later.

[0060] The specific surface area of ​​the first amorphous carbon is, for example, 10 to 100 m². 2 It may be within the range of / g. In this specification, the specific surface area may be measured by the method described in the evaluation examples below. In other examples, the specific surface area of ​​the first amorphous carbon is 20m². 2 / g or more, 30m 2 / g or more, or 40m 2 / g or more, or 90m 2 / g or less, 80m 2 / g or less, 70m2 / g or less, or 60m 2 It may be less than / g.

[0061] The specific surface area of ​​the second amorphous carbon is, for example, 110 to 230 m². 2 It may be within the range of / g. The specific surface area of ​​the second amorphous carbon is, in other examples, 120 m². 2 / g or more, 130m 2 / g or more, 140m 2 / g or more, or 150m 2 / g or more, or 220m 2 / g or less, 210m 2 / g or less, 200m 2 / g or less, 190m 2 / g or less, 180m 2 / g or less, 170m 2 / g or less, or 160m 2 It may be less than / g.

[0062] The ratio of the specific surface area of ​​the second amorphous carbon to the specific surface area of ​​the first amorphous carbon may be, for example, 4.5 or less. The ratio of the specific surface area of ​​the second amorphous carbon to the specific surface area of ​​the first amorphous carbon may, in other examples, be 4.4 or less, 4.3 or less, 4.2 or less, 4.1 or less, 4.0 or less, 3.9 or less, 3.8 or less, 3.7 or less, 3.6 or less, 3.5 or less, 3.4 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.0 or less, or 2.9 or less, or 0.1 or more, 0.5 or more, 1.0 or more, 1.5 or more, 2.0 or more, or 2.5 or more.

[0063] The negative electrode coating layer of the present invention may further include, for example, first aggregates formed by the aggregation of the first amorphous carbon and / or second aggregates formed by the aggregation of the second amorphous carbon. In this specification, aggregates may mean secondary particles. That is, in this specification, first aggregates may mean secondary particles of the first amorphous carbon, and second aggregates may mean secondary particles of the second amorphous carbon. The amorphous carbon contained in the negative electrode coating layer of the present invention may exist only in primary particle form, only in secondary particle form, or in a form in which primary and secondary particles are mixed.

[0064] The ratio of the average particle size of the first aggregate to the average particle size of the second aggregate may be, for example, in the range of 1.5 to 5. In this specification, the average particle size of the aggregate can be measured by the method described in the evaluation example later. In other examples, the ratio of the average particle size of the first aggregate to the average particle size of the second aggregate may be 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2.0 or more, 2.1 or more, or 2.2 or more, or 4.5 or less, 4.0 or less, 3.5 or less, 3.0 or less, or 2.5 or less. The non-negative electrode coating layer of the present invention can reduce the irreversible lithium amount per unit area by controlling the ratio of the average particle size of the first aggregate to the average particle size of the second aggregate as described above, thereby improving lifespan characteristics and performance.

[0065] The average particle size of the first aggregate may be, for example, in the range of 160 nm to 400 nm. In other examples, the average particle size of the first aggregate may be 170 nm or more, 180 nm or more, 190 nm or more, 200 nm or more, 210 nm or more, 220 nm or more, 230 nm or more, or 240 nm or more, or 380 nm or less, 360 nm or less, 340 nm or less, 320 nm or less, 300 nm or less, 280 nm or less, or 260 nm or less.

[0066] The average particle size of the second aggregate may be, for example, in the range of 50 nm to 150 nm. In other examples, the average particle size of the second aggregate may be 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, or 100 nm or more, or 140 nm or less, 130 nm or less, 120 nm or less, or 110 nm or less.

[0067] The first amorphous carbon and the second amorphous carbon may, for example, be one or more selected independently from the group consisting of carbon black, acetylene black, furnace black, Ketjen black, and graphene, but are not limited to these, and any amorphous carbon that can be used in a non-negative all-solid-state battery can be used without limitation.

[0068] The negative electrode coating layer of the present invention may further include, for example, a metal, quasimetallic element, or a combination thereof that forms an alloy or compound with lithium.

[0069] The metal, quasimetallic element, or combination thereof that forms an alloy or compound with the lithium may be one or more selected from the group consisting of, for example, gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).

[0070] The particle size of the metal, quasimetallic element, or combination thereof that forms an alloy or compound with the lithium may be, for example, in the range of 10 to 1000 nm. The particle size may refer to the maximum particle size, minimum particle size, or average particle size. In other examples, the particle size of the metal, quasimetallic element, or combination thereof that forms an alloy or compound with the lithium may be 20 nm or more, 30 nm or more, 40 nm or more, or 50 nm or more, or 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, or 100 nm or less.

[0071] The weight ratio of the total first amorphous carbon and second amorphous carbon to the metal, quasimetallic element, or combination thereof that forms an alloy or compound with the lithium may be, for example, in the range of 1 to 10. In other examples, the weight ratio of the total first amorphous carbon and second amorphous carbon to the metal, quasimetallic element, or combination thereof that forms an alloy or compound with the lithium may be 1.5 or more, 2 or more, or 2.5 or more, or 8 or less, 6 or less, or 4 or less.

[0072] The negative electrode coating layer of the present invention may further include, for example, a binder. The binder may be, for example, an aqueous binder, an organic binder, or a combination thereof. The binder may be, for example, polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, diacetylcellulose, polyvinylidene fluoride, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene, fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, or a combination thereof. The aqueous binder may be, for example, styrene-butadiene rubber, carboxymethylcellulose, or a combination thereof. The organic binder may be, for example, polytetrafluoroethylene, polyvinylidene fluoride, or a combination thereof.

[0073] The weight ratio between the first amorphous carbon, the second amorphous carbon, and the total metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium to the binder may, for example, be in the range of 5 to 50. The weight ratio between the first amorphous carbon, the second amorphous carbon, and the total metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium to the binder may, in other examples, be 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, 14 or more, 15 or more, 16 or more, 17 or more, 18 or more, 19 or more, 20 or more, 21 or more, 22 or more, or 23 or more, or 45 or less, 40 or less, 35 or less, 30 or less, or 25 or less. The present invention can provide an all-solid-state battery with excellent performance and life characteristics by controlling the weight ratio between the compositions contained in the non-negative electrode coating layer as described above.

[0074] The negative electrode coating layer of the present invention may further contain a solvent, for example. In the present invention, the meaning that the negative electrode coating layer further contains a solvent may mean that a solvent is used in the manufacturing process of the negative electrode coating layer, and may not mean that the negative electrode coating layer produced through drying or the like contains a solvent. Examples of the solvent include water and N-methylpyrrolidone (NMP).

[0075] The negative electrode coating layer of the present invention may further contain, for example, other additives. These other additives may include, without limitation, fillers, coating agents, dispersants, and ion-conducting additives used in conventional all-solid-state batteries, as long as they do not hinder the objectives of the present invention.

[0076] The negative electrode coating layer of the present invention can be manufactured, for example, by applying a slurry in which the materials constituting the negative electrode coating layer are dispersed onto a negative electrode current collector and drying it.

[0077] The thickness of the negative electrode coating layer of the present invention may be 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer described later. The thickness of the negative electrode coating layer may be, for example, in the range of 1 to 20 μm, 5 to 18 μm, or 9 to 15 μm. By controlling the thickness of the negative electrode coating layer as described above, it is possible to control the breakdown of the negative electrode coating layer by lithium dendrites formed between the negative electrode coating layer and the negative electrode current collector described later, thereby improving cycle characteristics, improving energy density, and reducing the internal resistance of the all-solid-state battery.

[0078] A second aspect of the present invention includes a positive electrode, a solid electrolyte layer, a non-negative electrode coating layer, and a negative electrode, wherein the non-negative electrode coating layer includes a first amorphous carbon and a second amorphous carbon, and the particle size analysis results obtained by a particle size analyzer (Mastersizer 3000), D 50 / D 10 This may relate to an all-solid-state battery characterized in that the value is within the range of 3.5 to 10.

[0079] The matters relating to the first aspect described above may apply similarly to the matters relating to the second aspect unless otherwise specified.

[0080] The non-negative electrode coating layer of the present invention may have a porosity in the range of 50 to 80%. The porosity of the non-negative electrode coating layer may be measured by the method described in the evaluation example later. In other examples, the porosity of the non-negative electrode coating layer may be 55% or more, 60% or more, or 65% or more, or 75% or less, or 70% or less.

[0081] The positive electrode may include, for example, a positive electrode current collector and / or a positive electrode active material layer.

[0082] As the positive electrode current collector, any known metal usable as a current collector for all-solid-state batteries can be used. For example, the positive electrode current collector can be a plate, mesh, or foil made of copper (Cu), nickel (Ni), aluminum (Al), vanadium (V), gold (Au), platinum (Pt), chromium (Cr), iron (Fe), zinc (Zn), indium (In), germanium (Ge), lithium (Li), magnesium (Mg), stainless steel, titanium (Ti), cobalt (Co), or an alloy thereof. The positive electrode current collector may be omitted in some cases.

[0083] The positive electrode active material layer may include, for example, a positive electrode active material, a solid electrolyte, a binder, and / or a conductive material.

[0084] The positive electrode active material reversibly absorbs and desorbs lithium ions. The positive electrode active material may be, for example, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganese oxide, lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, or any other material used as a positive electrode active material in the art. The positive electrode active materials may be used individually or in combination of two or more.

[0085] The lithium transition metal oxide is, for example, Li a A 1-b B b D2 (In the above formula, 0.90 ≤ a ≤ 1 and 0 ≤ b ≤ 0.5); Li a Ni 1-b-c Co b B c O 2-α F2(In the above equation, 0.90≦a≦1, 0≦b≦0.5, 0≦c≦0.05, and 0<α<2);Li a Ni 1-b-c Mn b B c D α (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 ≤ α ≤ 2); Li a Ni 1-b-c Co b B c D α (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 < α ≤ 2); Li a E 1-b B b O 2-c D c(In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE 2-b B b O 4-c D c (In the above formula, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b B c O 2-α F α (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a CoG b O2 (In the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a MnG b O2 (In the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a Mn2GbO4 (In the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li a Ni 1-b-c Mn b B c O 2-α F α (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni 1-b-c Mn b B c O 2-α F2 (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni b E c G d O2 (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0.001 ≤ d ≤ 0.1); Li a Ni b Co c Mn d GeO2 (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0.001 ≤ e ≤ 0.1); Li a NiG bO2 (In the above formula, 0.90 ≤ a ≤ 1 and 0.001 ≤ b ≤ 0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiIO2; LiNiVO4; Li (3-f) J2(PO4)3(0≦f≦2);Li (3-f) The compound may be represented by any one of the chemical formulas Fe2(PO4)3(0≦f≦2) or LiFePO4. In such a compound, A is Ni, Co, Mn, or a combination thereof; B 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; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof. As the positive electrode active material, a compound with a coating layer attached to its surface may be used, or a mixture of the aforementioned compound and the compound with the coating layer attached may be used. The coating layer added to the surface of such a compound may contain, for example, a lithium-ion conductive oxide. The lithium-ion conductive oxide may be, for example, LiNbO3, Li4Ti5O 12 Examples include, but are not limited to, Li3PO4. The compound forming such a coating layer may be amorphous or crystalline. Methods for forming the coating layer may include, for example, spray coating or immersion, but can be selected without limitation as long as they do not adversely affect the physical properties of the positive electrode active material.

[0086] If the positive electrode active material includes nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, it may be possible to increase the capacity density of the all-solid-state battery and reduce the metal leaching of the positive electrode active material in the charged state. This may improve the cycle characteristics of the all-solid-state battery in the charged state.

[0087] The shape of the positive electrode active material may be, for example, a perfect sphere, an ellipsoid, or some other particle shape. The particle size of the positive electrode active material is not particularly limited and should be within a range applicable to the positive electrode active material of conventional all-solid-state secondary batteries. The content of the positive electrode active material in the positive electrode is also not particularly limited and should be within a range applicable to the positive electrode of conventional all-solid-state secondary batteries.

[0088] The solid electrolyte contained in the positive electrode active material layer may be the same as or different from the solid electrolyte contained in the solid electrolyte layer, for example. The solid electrolyte contained in the positive electrode active material layer may be a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a phosphate-based solid electrolyte, or a halide-based solid electrolyte, but is not limited thereto; any electrolyte commonly used in all-solid-state batteries is acceptable.

[0089] The solid electrolyte contained in the positive electrode active material layer may have a smaller average particle size than, for example, the solid electrolyte contained in the solid electrolyte layer. For example, the average particle size of the solid electrolyte contained in the positive electrode active material layer may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the average particle size of the solid electrolyte contained in the solid electrolyte layer.

[0090] The binder contained in the positive electrode active material layer may be, for example, acrylonitrile butadiene rubber (ABR), butadiene rubber (BR), styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc.

[0091] The conductive material contained in the positive electrode active material layer may be, for example, graphite, carbon black, acetylene black, Ketjen black, carbon fiber, or metal powder.

[0092] The positive electrode active material layer may further contain additives such as fillers, coating agents, dispersants, and ion-conducting additives, and these additives can be used without limitation as long as they are known materials commonly used in electrodes for all-solid-state batteries.

[0093] The solid electrolyte layer may, for example, contain a sulfide-based solid electrolyte. The sulfide-based solid electrolyte may be, for example, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-Li3PO4, or Li2S-SiS2-Li p MO q (p and q are positive numbers, M is one of P, Si, Ge, B, Al, Ga, and In), Li2S-SiS2-P2S5-LiI, Li2S-P2S5, Li2S-P2S5-LiX (X is a halogen element), Li2S-B2S3, Li2S-P2S5-Z m S n (m and n are positive numbers), Z is one of Ge, Zn, or Ga, L i2 S-GeS2, Li 7-x PS 6-x Cl x (0≦x≦2), Li 7-x PS 6-x Br x (0≦x≦2), and Li 7-x PS 6-x I x It can be one or more selected from (0≦x≦2). Sulfide-based solid electrolytes can be manufactured by processing starting materials such as Li2S and P2S5 by methods such as melt-quenching or mechanical milling. Furthermore, heat treatment can be performed after such processing. The solid electrolyte can be amorphous, crystalline, or a mixture thereof. In the present invention, the sulfide-based solid electrolyte may be, for example, one in which the sulfide-based solid electrolyte material contains sulfur (S), phosphorus (P), and lithium (Li) as at least constituent elements.

[0094] The aforementioned sulfide-based solid electrolyte is, for example, Li 7-x PS 6-x Cl x (0≦x≦2), Li 7-x PS 6-x Br x (0≦x≦2), and Li 7-x PS 6-x I x The compound may be an argyrodite-type compound containing at least one selected from (0 ≤ x ≤ 2). In particular, sulfide-based solid electrolytes may be argyrodite-type compounds containing one or more selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0095] The density of the argyrodite-type solid electrolyte may be, for example, 1.5 to 2.0 g / cc. Having a density of 1.5 g / cc or higher for the argyrodite-type solid electrolyte reduces the internal resistance of the all-solid-state secondary battery, effectively suppressing penetration of the solid electrolyte by Li.

[0096] The elastic modulus of the solid electrolyte may be, for example, 15 to 35 GPa.

[0097] The solid electrolyte layer may, for example, include a binder. The binder included in the solid electrolyte layer may be, for example, one of the types of binders included in the positive electrode active material layer, but is not limited to these, and any binder used in the art may be included. The binder included in the solid electrolyte layer may be the same as or different from the binder included in the positive electrode active material layer and / or the non-negative electrode coating layer described above.

[0098] The negative electrode of the present invention may include, for example, a negative electrode current collector.

[0099] The negative electrode current collector can be made of a known metal usable as a current collector in an all-solid-state battery. The negative electrode current collector can be made of a material that does not form alloys or compounds with lithium, for example. The negative electrode current collector can be made of a material selected from the group consisting of, for example, copper (Cu), nickel (Ni), aluminum (Al), vanadium (V), gold (Au), platinum (Pt), magnesium (Mg), iron (Fe), titanium (Ti), cobalt (Co), chromium (Cr), zinc (Zn), germanium (Ge), indium (In), and stainless steel, but is not limited thereto. Any material used as an electrode current collector in the art can be used as long as it does not hinder the purpose of the present invention. The negative electrode current collector may be made of one of the aforementioned metals or an alloy or coating material of two or more metals. The negative electrode current collector may be in the form of, for example, a plate, mesh, or foil, but is not limited thereto.

[0100] The negative electrode of the present invention may further include, for example, a thin film containing an element capable of forming an alloy with lithium on the negative electrode current collector. The thin film may be placed between the negative electrode current collector and the non-negative electrode coating layer. The element capable of forming an alloy with lithium may be, but is not limited to, gold, silver, zinc, tin, indium, silicon, aluminum, bismuth, etc., and any element capable of forming an alloy with lithium in the art can be used. The thin film may consist of one of the above examples or of several types of alloys. The further inclusion of such a thin film in the negative electrode of the present invention can further improve the cycle characteristics of the all-solid-state battery.

[0101] The thickness of the thin film may be, for example, 1 to 800 nm, 10 to 700 nm, 50 to 600 nm, or 100 to 500 nm. The thin film may be formed by, for example, vacuum deposition, sputtering, or plating, but is not limited to these methods; any method capable of forming a thin film in the art is acceptable.

[0102] The all-solid-state battery of the present invention may, upon charging, further include a metal and / or a layer containing lithium or a lithium alloy between, for example, the negative electrode current collector and the non-negative electrode coating layer, and / or within the non-negative electrode coating layer. The lithium alloy may be, for example, Li-Al alloy, Li-Sn alloy, Li-In alloy, Li-Ag alloy, Li-Au alloy, Li-Zn alloy, Li-Ge alloy, Li-Si alloy, or any other alloy used as a lithium alloy in the art. The metal or metal layer contained between, and / or within, the negative electrode current collector and the non-negative electrode coating layer may be composed of one or more of these alloys or of lithium.

[0103] The thickness of the metal layer containing lithium or a lithium alloy may be, for example, within the range of 1 to 1000 μm, 1 to 500 μm, 1 to 200 μm, 1 to 150 μm, 1 to 100 μm, or 1 to 50 μm. The thickness needs to be controlled as described above in order for the metal layer to function as a lithium storage vessel and improve cycle characteristics.

[0104] The aforementioned metal layer may be formed, for example, by deposition between the negative electrode current collector and the non-negative electrode coating layer during charging after the assembly of the all-solid-state battery. When a metal layer is formed between the negative electrode current collector and the non-negative electrode coating layer during charging after the assembly of the all-solid-state battery, the negative electrode current collector, the non-negative electrode coating layer, and the region between them may be, for example, a lithium-free (Li-Free) region that does not contain lithium in the initial state or after discharge of the all-solid-state battery.

[0105] The all-solid-state battery of the present invention may have a capacity retention rate of 60% or more even after 300 cycles. In other examples, the all-solid-state battery of the present invention may have a capacity retention rate of 65% or more, 70% or more, 75% or more, 80% or more, 81% or more, 82% or more, or 83% or more even after 300 cycles. The capacity retention rate after the said cycles may be measured by the evaluation examples described later.

[0106] In the following, the present invention will be described in detail with reference to examples in order to specifically illustrate the disclosures of the present invention as described above and the intended functions and effects of the present invention. However, the examples may be modified into several different forms, and the scope of this specification should not be construed as being limited to these examples alone. It should be emphasized that the examples are provided to specifically illustrate the present invention to those skilled in the art.

[0107] Example 1

[0108] (Negative electrode fabrication)

[0109] First amorphous carbon, second amorphous carbon, silver (Ag) nanoparticles (particle size 60 nm), binder (PVdF), and NMP solution were placed in a mixer (THINKY Corporation) container and mixed repeatedly at 2000 rpm for 3 minutes 12 times. Subsequently, after adding more NMP solution, the slurry was mixed repeatedly at 2000 rpm for 3 minutes 5 times and coated onto a 10 μm thick SUS foil using a bar coater. After drying in air at 80°C for 20 minutes, it was vacuum dried at 100°C for 12 hours. Through this process, a negative electrode was obtained in which a non-negative electrode coating layer with a thickness of 10.57 μm and a porosity of 65.1% was formed on the SUS foil.

[0110] In this case, the first amorphous carbon has an average particle size of 41 nm for primary particles, an average particle size of 250 nm for secondary particles, and a specific surface area of ​​54 m². 2 Using carbon black at a density of / g, the secondary amorphous carbon has an average primary particle size of 20nm, an average secondary particle size of 109nm, and a specific surface area of ​​154m². 2Carbon black was used in a quantity of / g. The first amorphous carbon and the second amorphous carbon were mixed in a weight ratio of 9:1 (first amorphous carbon:second amorphous carbon), the weight ratio between amorphous carbon (total amount of amorphous carbon included) and silver (Ag) nanoparticles was 3:1 (amorphous carbon:silver nanoparticles), and the weight ratio between the binder and the total amount of amorphous carbon (total amount of amorphous carbon included) and silver nanoparticles was 6.5:93.5 (binder:total amount of amorphous carbon and silver nanoparticles).

[0111] (Positive electrode fabrication)

[0112] LiNi 0.8 Co 0.15 Mn 0.05 O2(NCM) was prepared. Li6PS5Cl, an argyrodite-type crystalline material, was prepared as the solid electrolyte. Polytetrafluoroethylene (Teflon® binder, DuPont) was prepared as the binder. Carbon nanofibers (CNF) were prepared as the conductive agent. These materials were then mixed in a weight ratio of positive electrode active material:solid electrolyte:conductive agent:binder = 84:15:0.2:1.2, and the mixture was formed into a large sheet to create a positive electrode sheet. This positive electrode sheet was then pressed onto an 18μm thick aluminum foil positive electrode current collector to create the positive electrode. The initial charge capacity of the positive electrode (charge capacity in the first cycle) was approximately 20mAh at a charge of 4.25V. The weight of the positive electrode was approximately 110mg (approximately 203mAh / g of active material weight).

[0113] (solid electrolyte)

[0114] Li6PS5Cl solid electrolyte was used as the solid electrolyte.

[0115] (Fabrication of all-solid-state batteries)

[0116] A solid-state battery was fabricated by stacking a positive electrode, a solid electrolyte, and a negative electrode, and sealing them in a pouch under vacuum. The positive electrode current collector and the negative electrode current collector were made to protrude from the pouch to maintain the battery's vacuum. These protruding parts served as the positive and negative electrode terminals. Furthermore, this solid-state battery was subjected to hydrostatic treatment at 500 MPa for 30 minutes. This hydrostatic treatment significantly improved the battery's performance.

[0117] Example 2

[0118] An all-solid-state battery was obtained using the same method as in Example 1, except that during negative electrode fabrication, the weight ratio between the binder and the total amount of amorphous carbon (total amount of amorphous carbon included) and the total amount of silver nanoparticles was set to 4:96 (binder:total amount of amorphous carbon and silver nanoparticles), and a negative electrode with a thickness of 14.4 μm and a porosity of 64.9% was formed on a SUS foil.

[0119] Comparative Example 1

[0120] An all-solid-state battery was obtained using the same method as in Example 1, except that, during the negative electrode fabrication process, only first amorphous carbon was introduced as the amorphous carbon, and a non-negative electrode coating layer with a thickness of 11.00 μm and a porosity of 67.6% was formed on a SUS foil.

[0121] Comparative Example 2

[0122] An all-solid-state battery was obtained using the same method as in Example 1, except that during the negative electrode fabrication, the weight ratio between the first amorphous carbon and the second amorphous carbon was set to 5:5, and a negative electrode without a negative electrode coating layer with a thickness of 10.33 μm and a porosity of 64.3% was formed on a SUS foil.

[0123] Comparative Example 3

[0124] During the fabrication of the negative electrode, the primary particle size of the secondary amorphous carbon was 12 nm, the secondary particle size was 48 nm, and the specific surface area was 249 m². 2An all-solid-state battery was obtained using the same method as in Example 1, except that a negative electrode was manufactured by forming a non-negative electrode coating layer with a thickness of 10.33 μm and a porosity of 66.8% on a SUS foil using carbon black of / g.

[0125] Comparative Example 4

[0126] An all-solid-state battery was obtained using the same method as in Example 1, except that during the negative electrode fabrication, the weight ratio between the first amorphous carbon and the second amorphous carbon was set to 8:2 (first amorphous carbon:second amorphous carbon), and a negative electrode without a negative electrode coating layer with a thickness of 16.0 μm and a porosity of 64.2% was formed on a SUS foil.

[0127] Comparative Example 5

[0128] An all-solid-state battery was obtained using the same method as in Example 1, except that during the negative electrode fabrication, the weight ratio between the first amorphous carbon and the second amorphous carbon was set to 7:3 (first amorphous carbon:second amorphous carbon), and a negative electrode without a negative electrode coating layer with a thickness of 11.0 μm and a porosity of 61.9% was formed on a SUS foil.

[0129] Evaluation Example 1. Average particle size of primary and secondary particles of amorphous carbon.

[0130] The average particle size of the primary amorphous carbon was measured using a scanning electron microscope (SEM) (FEI sirion), and the average particle size of the secondary amorphous carbon was measured using a particle size analyzer (Beckman Coulter LS13 320).

[0131] Evaluation Example 2: Specific surface area of ​​amorphous carbon

[0132] The specific surface area of ​​amorphous carbon was measured using the commonly used BET method (Brunauer, Emmett, and Teller method). Specifically, the specific surface area of ​​amorphous carbon was calculated when the residual pressure of each sample was 10 at 298 K. -3After releasing gas for approximately 6 hours until torr (out-gassing), the amount of N2 gas adsorbed at 77K was measured using a Micromeritics ASAP 2460 instrument to determine the surface adsorption properties of carbon black. BET development of micropores and S BJH This was derived by analyzing the stomata as a result.

[0133] Evaluation Example 3. Particle Size Distribution of Slurry with Non-Anode Coating Layer

[0134] (1) Slurry sample separation

[0135] A portion of the non-negative electrode coating layer slurry from the above examples and comparative examples was taken and diluted in NMP solution to prepare analytical samples.

[0136] (2)Analytical equipment

[0137] The particle size analysis of the aforementioned sample was performed using a particle size analyzer (Mastersizer 3000, Malvem panalytical).

[0138] Specifically, the analytical samples prepared in (1) above were placed into the sample input port of the apparatus, and particle size analysis was carried out under the following set conditions.

[0139] ◎ Particle Type: Carbon C

[0140] ◎ Material:

[0141] - Material name: Carbon C (carbon black)

[0142] - Refractive index: 1.746

[0143] - Adsorption index: 1.000

[0144] ◎ light source:

[0145] - Red light source:Max. 4mW He-Ne,632.8nm

[0146] - Blue light source:Max. 10mW LED,470nm

[0147] ◎ Dispersant:

[0148] - Dispersant name: NMP

[0149] - Refractive index: 1.465

[0150] ◎ Measurement obscuration limits:10-15%

[0151] ◎Analysis model:Mie scattering

[0152] (3) Results

[0153] The volume-based particle size distribution analysis results of the non-negative electrode coating layer slurry according to the above method are shown in Tables 1 and 2, and Figures 2 to 8 below. Table 2 shows the x-axis and y-axis values ​​for each of the two peaks that appear at 0.1 μm and 0.5 μm in the particle size analysis graph.

[0154] [Table 1]

[0155] [Table 2]

[0156] Evaluation Example 4. Cell Lifetime Characteristics

[0157] The all-solid-state batteries (pouch-type monocells) of the above-mentioned examples and comparative examples were driven under the following charge-discharge conditions in an operating voltage range of 4.25V to 3.0V and an operating temperature of 60°C to evaluate their cycle characteristics, and the results are shown in Figure 1.

[0158] Charging conditions: 0.33C, 4.25V CC / CV, 0.1C cut-off

[0159] Discharge conditions: 0.33C, 3.0V, CC

Claims

1. It comprises first amorphous carbon and second amorphous carbon, Particle size analysis results using a particle size analyzer (Mastersizer 3000), D ５０ / D １０ A non-negative electrode coating layer characterized in that the value is within the range of 3.5 to 10.

2. The aforementioned D １０ The non-negative electrode coating layer according to claim 1, characterized in that its thickness is 0.06 μm or less.

3. The aforementioned D １０ The non-negative electrode coating layer according to claim 1, characterized in that the thickness is 0.03 μm or more.

4. The non-negative electrode coating layer according to claim 1, characterized in that the graph of the particle size analysis results obtained by a particle size analyzer (Mastersizer 3000), with particle size (size) on the x-axis (μm) and volume density (volume density) on the y-axis (%), has two peaks at 0.1 μm to 0.5 μm and satisfies the following formula 1: [Formula 1] 1.0≦{(x ２ — １ ) / x １ }*(y １ / y ２ )≦2.0 In the above formula, x １ and x ２ These are the x-axis values ​​of the two peaks mentioned above, and x １ <x ２ And y １ is x １ The value of the y-axis at the peak, y ２ is x ２ This is the value on the y-axis at the peak.

5. The ratio of the average particle size of the primary particles of the first amorphous carbon to the average particle size of the primary particles of the second amorphous carbon is in the range of 1.1 to 3.

3. The non-negative electrode coating layer according to claim 1, characterized in that the weight ratio of the first amorphous carbon to the second amorphous carbon is in the range of 5 to 20.

6. The non-negative electrode coating layer according to claim 1, characterized in that the average particle size of the primary particles of the first amorphous carbon is in the range of 30 nm to 50 nm.

7. The non-negative electrode coating layer according to claim 1, characterized in that the average particle size of the primary particles of the second amorphous carbon is in the range of 15 nm to 25 nm.

8. The specific surface area of ​​the first amorphous carbon is 10 to 100 m². ２ The non-negative electrode coating layer according to claim 1, characterized in that it is within the range of / g.

9. The specific surface area of ​​the second amorphous carbon is 110 to 230 m². ２ The non-negative electrode coating layer according to claim 1, characterized in that it is within the range of / g.

10. The non-negative electrode coating layer according to claim 1, characterized in that the first amorphous carbon and the second amorphous carbon are each independently selected from the group consisting of carbon black, acetylene black, furnace black, Ketjen black, and graphene.

11. The non-negative electrode coating layer according to claim 1, further comprising a metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium.

12. The non-negative electrode coating layer according to claim 11, characterized in that the metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium is one or more selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).

13. The negative electrode coating layer according to claim 11, characterized in that the weight ratio between the total of the first amorphous carbon and the second amorphous carbon to the metal, quasimetallic element, or combination thereof that forms an alloy or compound with lithium is in the range of 1 to 10.

14. The non-negative electrode coating layer according to claim 11, further comprising a binder.

15. The non-negative electrode coating layer according to claim 14, characterized in that the weight ratio between the binder and the total of the first amorphous carbon, the second amorphous carbon, and the metals, quasimetallic elements, or combinations thereof that form alloys or compounds with lithium is in the range of 5 to 50.

16. It comprises a positive electrode, a solid electrolyte layer, a non-negative electrode coating layer, and a negative electrode. The aforementioned non-negative electrode coating layer contains first amorphous carbon and second amorphous carbon, and the particle size analysis results obtained by a particle size analyzer (Masteriser 3000) are D ５０ / D １０ A solid-state battery characterized in that the value is within the range of 3.5 to 10.

17. The all-solid-state battery according to claim 16, characterized in that the solid electrolyte layer contains a sulfide-based solid electrolyte.

18. The all-solid-state battery according to claim 16, characterized in that the porosity of the non-negative electrode coating layer is in the range of 50 to 80%.

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