Anode assembly, manufacturing method therefor, and all-solid-state battery comprising same

Abstract

The present invention relates to an anode assembly, a manufacturing method therefor, and an all-solid-state battery comprising same, the anode assembly comprising a first layer that includes LiX, a second first layer that includes amorphous carbon, and an anode current collector, wherein X is a halogen element. According to the present invention, the anode assembly having excellent charge and discharge efficiency and capacity retention rate, the manufacturing method therefor, and the all-solid-state battery comprising same can be provided.

Description

Cathode assembly, method for manufacturing same, and all-solid-state battery including same

[0001] The present invention relates to a cathode assembly, a method for manufacturing the same, and an all-solid-state battery including the same.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0020272, filed February 13, 2024, the entire contents of which are incorporated herein by reference.

[0003] Recent industrial demands have led to the development of all-solid-state batteries with high energy density and stability, and ongoing efforts are underway to further improve these properties. For example, research is underway into using lithium as an anode material to increase the energy density of all-solid-state batteries.

[0004] As a method of using lithium as an anode active material, a method of using lithium or a lithium alloy as an anode active material layer during the battery manufacturing process, or a method of forming a lithium layer during the charging process without forming a separate anode active material layer on the anode current collector during the battery manufacturing process have been proposed.

[0005] However, when lithium is used as an anode active material, lithium (metallic lithium) is deposited on the anode side during charging, and as the charging and discharging process is repeated, lithium dendrites grow through the gaps in the solid electrolyte layer, which causes a battery short circuit or a decrease in capacity, which is a problem.

[0006] Therefore, in order to commercialize the method of using lithium as an anode active material, it is necessary to improve the above problems.

[0007] The background information provided herein is intended to provide a general context for the disclosure. Unless otherwise stated herein, the material described in this section is not prior art to the claims of this application, and its inclusion in this section does not constitute prior art or a suggestion of prior art.

[0008] The present invention aims to solve the above problems and provides a cathode assembly having excellent charge / discharge efficiency and capacity retention rate, a method for manufacturing the same, and an all-solid-state battery including the same.

[0009] One aspect of the present invention relates to a negative electrode assembly comprising: a first layer comprising LiX; a second layer comprising amorphous carbon; and a negative electrode current collector; wherein X is a halogen element.

[0010] In one embodiment, the first layer may be characterized as consisting essentially of LiX.

[0011] In one embodiment, the first layer may be characterized by comprising at least 96 wt% of the LiX based on the total weight of the first layer.

[0012] In one embodiment, the first layer may be characterized as being closer to the negative electrode current collector than the second layer.

[0013] In one embodiment, the thickness of the first layer may be characterized as being 10 nm to 990 nm.

[0014] In one embodiment, the thickness of the second layer may be characterized as being 1 ㎛ to 50 ㎛.

[0015] In one embodiment, the ratio of the thickness of the second layer to the thickness of the first layer may be 10 to 200.

[0016] In one embodiment, the LiX may be characterized as being LiF or LiCl.

[0017] In one embodiment, the amorphous carbon may be characterized by being at least one selected from the group consisting of carbon black, acetylene black, furnace black, Ketjen black, and graphene.

[0018] In one embodiment, the second layer may be characterized by further comprising a binder.

[0019] In one embodiment, the method may further include a third layer positioned between the first layer and the second layer and including a lithium-affinity material.

[0020] In one embodiment, the thickness of the third layer may be characterized as being 10 nm to 990 nm.

[0021] In one embodiment, the second layer may be characterized by further comprising a lithium-affinity material.

[0022] Another aspect of the present invention relates to an all-solid-state battery comprising a positive electrode, a solid electrolyte layer, and the negative electrode assembly.

[0023] In one embodiment, the all-solid-state battery may be characterized as a non-anode all-solid-state battery using lithium or a lithium alloy as an anode active material.

[0024] In one embodiment, the solid electrolyte layer may be characterized by including a sulfide-based solid electrolyte.

[0025] In one embodiment, the sulfide-based solid electrolyte is 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, Li2S-SiS2-Li p MO q(p, 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, n are positive numbers), Z is one of Ge, Zn or Ga, Li2S-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 characterized by at least one selected from (0≤x≤2).

[0026] In one embodiment, the all-solid-state battery of the present invention may be characterized by a charge / discharge efficiency of 90% or more.

[0027] In one embodiment, the all-solid-state battery of the present invention may be characterized by a capacity retention rate of 90% or more after 50 cycles.

[0028] In one embodiment, the all-solid-state battery of the present invention may be characterized by a specific capacity of 150 mAh / g or more after 50 cycles as a result of a mini monocell cycle evaluation.

[0029] Another aspect of the present invention relates to a method for manufacturing a negative electrode assembly, which comprises forming a first layer and a second layer on a negative electrode current collector, wherein the first layer comprises LiX, wherein X is a halogen element, and the second layer comprises amorphous carbon.

[0030] In one embodiment, the step of forming the second layer may be characterized by including the step of applying a slurry including amorphous carbon onto the first layer and the step of drying.

[0031] In one embodiment, the slurry may be characterized by further comprising a binder and a solvent.

[0032] According to the present invention, it is possible to provide a cathode assembly having excellent charge / discharge efficiency and capacity retention rate, a method for manufacturing the same, and an all-solid-state battery including the same.

[0033] The attached drawings illustrate embodiments of the present invention and, together with the detailed description below, are helpful in further understanding the technical aspects of the present invention and should not be construed as limiting the present invention.

[0034] Figure 1 is a graph showing the results of the charge / discharge characteristic evaluation of Example 1 and Comparative Example 1.

[0035] Figure 2 is a graph showing the results of the charge / discharge characteristic evaluation of Example 2 and Comparative Example 2.

[0036] Figure 3 is a graph showing the results of the charge / discharge characteristic evaluation of Example 3 and Comparative Example 3.

[0037] Figure 4 is a graph showing the results of evaluating the specific capacity according to the cycle of the all-solid-state batteries of Examples and Comparative Examples 1 to 3.

[0038] Figure 5 is a graph showing the results of capacity retention rate evaluation according to cycle of the all-solid-state batteries of Examples and Comparative Examples 1 to 3.

[0039] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0040] Accordingly, the configuration of the embodiments described in this specification is only one of the most preferred embodiments of the present invention and does not represent all of the technical ideas of the present invention, so it should be understood that various equivalents and modified examples that can replace them may exist at the time of filing this application.

[0041] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0042] When a part in this specification is said to “comprise” a certain component, this does not exclude other components unless specifically stated to the contrary, but rather means that other components may be included. Thus, for example, a composition comprising compound A may include compounds other than A. However, the term “comprise” also encompasses, as a specific embodiment thereof, the more restrictive meanings of “consisting essentially / essentially of” and “consisting of,” so that, for example, “a composition comprising compound A” may also consist (essentially / essentially) of compound A.

[0043] In this connection, it should be understood that terms such as “have” or “have” as used 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.

[0044] When it is said in this specification that any layer is located “on” or “between” any other layer, this includes not only cases where any layer is in contact with any other layer, but also cases where another layer or material, etc., exists between the two layers.

[0045] Where an amount, concentration, or other value or parameter is given herein as a range, a preferred range, or an enumeration of an upper preferred value and a lower preferred value, this should be understood to specifically disclose any range that can be formed by any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether the range is separately disclosed. Where a range of numerical values ​​is recited herein, unless otherwise stated, e.g., there is no limiting term such as greater than, less than, etc., the range is intended to include the endpoint values ​​and all integers and fractions within the range. The scope of the present invention is not intended to be limited to the specific values ​​recited when defining a range.

[0046] Among the properties mentioned in this specification, if the measurement temperature affects the property, the property is measured at room temperature unless otherwise specified. The term "room temperature" refers to the natural temperature without heating or cooling, and may mean, for example, any temperature within the range of about 10°C to 30°C, or about 23°C or about 25°C. In addition, unless otherwise specified, the unit of temperature in this specification is ℃.

[0047] In addition, among the properties mentioned in this specification, if the measurement pressure affects the property, the property is measured at normal pressure, i.e., atmospheric pressure (approximately 1 atm), unless otherwise specified.

[0048] In this specification, “all-solid-state battery” may mean an all-solid-state secondary battery, and may also be referred to as a cell, secondary battery, or battery.

[0049] In this specification, “non-anode all-solid-state battery” means an all-solid-state battery that does not form a separate anode active material layer on the anode current collector, and may mean an all-solid-state battery in which lithium is deposited on the anode current collector during charging of the all-solid-state battery to form a lithium layer or a lithium alloy layer, and the lithium or lithium alloy functions as an anode active material in the all-solid-state battery.

[0050] A first aspect of the present invention relates to a cathode assembly.

[0051] The above negative electrode assembly may include a first layer comprising LiX; a second layer comprising amorphous carbon; and a negative electrode current collector; wherein X may be a halogen element.

[0052] The above halogen element may include at least one selected from F, Cl, Br, and I.

[0053] The first layer may be characterized as consisting essentially of LiX. That the first layer consists essentially of LiX may mean that the first layer is essentially composed of LiX, for example, it may mean that the first layer includes LiX as a main component.

[0054] Specifically, the first layer may mean that it includes LiX as a main component and the remaining components as impurities. For example, the first layer being essentially composed of LiX may mean that the first layer includes 90 wt% or more, 91 wt% or more, 92 wt% or more, 93 wt% or more, 94 wt% or more, 95 wt% or more, 96 wt% or more, 97 wt% or more, 98 wt% or more, or 99 wt% or more of LiX based on the total weight of the first layer, and for example, it may mean that it includes 99.5 wt% or more, 99.8 wt% or more, or 99.9 wt% or more, but is not limited thereto.

[0055] The first layer may be characterized by containing, for example, 96 wt% or more of LiX based on the total weight of the first layer. In other examples, the first layer may contain 97 wt% or more, 98 wt% or more, 99 wt% or more, 99.9 wt% or more, or 99.99 wt% or more of LiX, and most preferably 100 wt%, but this does not mean that the inclusion of unintended impurities is completely excluded. That is, the first layer may be characterized by containing only LiX. The first layer may be formed, for example, according to a deposition method described below, but is not limited thereto. In the present invention, by making the first layer contain LiX in the above range, preferably only LiX, it is possible to manufacture the first layer as a thinner layer than when it further contains a material other than LiX (e.g., a binder, etc.), thereby minimizing the thickness of the negative electrode assembly, preventing a decrease in capacity and charge / discharge speed due to resistance caused by the binder, etc., and contributing to an improvement in energy density.

[0056] The first layer and the second layer included in the negative electrode assembly may be a coating layer, and the coating layer may mean a non-cathode coating layer, but is not limited thereto. For example, the negative electrode assembly may include a coating layer and a negative electrode current collector.

[0057] In this specification, the term "coating layer" means a layer formed on the negative electrode current collector and / or between the negative electrode current collector and the solid electrolyte layer in an all-solid-state battery in which a lithium (alloy) layer is formed during the charging process without forming a separate negative electrode active material layer on the negative electrode current collector during the battery manufacturing process. Meanwhile, during the discharge process, lithium in the coating layer and / or the lithium (alloy) layer is ionized and moves toward the positive electrode. This may be different in structure and operating mechanism from the conventional case in which a negative electrode active material layer is formed on the negative electrode current collector during the battery manufacturing process. The coating layer can serve as a protective layer for the lithium (alloy) layer that prevents the lithium (alloy) layer formed during the charging process from directly contacting the solid electrolyte layer described below, and can suppress the growth of lithium dendrites, thereby eliminating short circuits in the all-solid-state battery and improving performance, etc.

[0058] The above negative electrode assembly may be characterized by sequentially including a first layer comprising LiX and / or a second layer comprising amorphous carbon from the negative electrode current collector, wherein X may be a halogen element.

[0059] In this specification, the fact that the cathode-free coating layer sequentially includes layers A, B, and C is only intended to indicate the order of lamination, and does not exclude the possibility that other separate layers may be additionally interposed between layers A, B, and C.

[0060] The above negative electrode assembly includes, but is not limited to, a first layer, a second layer, and a negative electrode current collector as described above.

[0061] Alternatively, the negative electrode assembly may include, but is not limited to, a structure in which a negative electrode current collector, a first layer, and a second layer are sequentially laminated. For example, it may mean that the first layer is positioned on one surface of the negative electrode current collector, and the second layer is positioned on one surface of the first layer. In other words, it may mean that the first layer is positioned between the negative electrode current collector and the second layer.

[0062] In addition, the negative electrode assembly may mean that the first layer may be positioned on both sides of the negative electrode current collector, and the second layer may be positioned on a plurality of the first layers positioned on both sides of the negative electrode current collector.

[0063] The first layer may be characterized by being closer to the negative electrode current collector than the second layer, but is not limited thereto.

[0064] For example, the negative electrode current collector may include a structure in which the first layer and the second layer are alternately laminated in the vertical direction of the negative electrode current collector, or may include a structure in which the first layer and the second layer are alternately laminated in the horizontal direction of the negative electrode current collector and are positioned on the negative electrode current collector, but is not limited thereto.

[0065] The thickness of the first layer may be, for example, characterized by being 10 nm to 990 nm. The thickness of the layer in the present specification may be an average thickness, a minimum thickness, and / or a maximum thickness, and may be measured, for example, by SEM, but is not limited thereto. The thickness of the first layer is, in other examples, 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, 100 nm or more, 110 nm or more, 120 nm or more, 130 nm or more, 140 nm or more, 150 nm or more, 160 nm or more, 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 950 nm or less, 900 nm or less, 850 nm or less, 800 nm or less, 750 nm or less, 700 nm or less, 650 nm or less, 600 nm or less, 550 nm or less, 500 nm or less, 450 nm or less, It may be 400 nm or less, 350 nm or less, or 300 nm or less. By controlling the thickness of the first layer within the above range, an all-solid-state battery with high charge / discharge efficiency and capacity retention rate can be provided.

[0066] The thickness of the second layer may be, for example, characterized by being 1 ㎛ to 50 ㎛. In other examples, the thickness of the second layer may be 2 ㎛ or more, 3 ㎛ or more, 4 ㎛ or more, 5 ㎛ or more, 6 ㎛ or more, 7 ㎛ or more, 8 ㎛ or more, or 9 ㎛ or more, or 45 ㎛ or less, 40 ㎛ or less, 35 ㎛ or less, 30 ㎛ or less, 25 ㎛ or less, 20 ㎛ or less, or 15 ㎛ or less. By controlling the thickness of the second layer within the above range, it is possible to prevent the metal layer formed between the first layer and the second layer during charging from directly contacting the solid electrolyte layer, while at the same time alleviating volume expansion during charging and improving the uniformity of the metal layer.

[0067] The ratio of the thickness of the second layer to the thickness of the first layer may be, for example, 10 to 200. In other examples, the ratio of the thickness of the second layer to the thickness of the first layer may be 15 or more, 20 or more, 25 or more, 30 or more, or 35 or more, or 180 or less, 160 or less, 140 or less, 120 or less, 100 or less, 80 or less, or 60 or less. By controlling the thickness ratio of the first layer and the second layer within the above range, the cycle characteristics of the all-solid-state battery can be improved.

[0068] The above LiX may be characterized as, for example, LiF or LiCl.

[0069] The above amorphous carbon may be characterized by being at least one selected from the group consisting of, for example, carbon black, acetylene black, furnace black, Ketjen black, and graphene, but is not limited thereto.

[0070] The above amorphous carbon has, for example, an average particle diameter (D 50 ) may be 150 nm or less. In this specification, the average particle diameter of the amorphous carbon may be measured by SEM or a particle size analyzer, etc. In other examples, the amorphous carbon may have an average particle diameter of 140 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, or 50 nm or less, or 10 nm or more, 20 nm or more, 30 nm or more, or 40 nm or more. By controlling the average particle diameter of the amorphous carbon within the above range, lithium ions can be moved well during charge and discharge and uniformly deposited between the negative electrode current collector and the non-anode coating layer.

[0071] The above amorphous carbon has, for example, a BET surface area of ​​10 m 2 / g to 200 m 2 / g range. In this specification, the BET specific surface area of ​​amorphous carbon may be measured by the method of the commonly used BET method (Brunauer, Emmett, and Teller's method). In another example, the amorphous carbon has a BET specific surface area of ​​20 m 2 / g or more, 30 m 2 / g or more, 40 m 2 / g or more or 50 m 2 / g or more, or 150 m 2 / g or less, 100 m 2 / g or less, 70 m 2 / g or less or 60 m 2 / g can be less.

[0072] The second layer may be characterized by further including, for example, a binder.

[0073] The binder included in the second layer may be, for example, an aqueous binder, an organic binder, or a combination thereof. The binder may be, for example, a polymer including polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinylidene fluoride, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene, fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylate styrene-butadiene rubber, epoxy resin, nylon, or a combination thereof. The aqueous binder may be, for example, styrene butadiene rubber, carboxymethyl cellulose, or a combination thereof. As the organic binder, for example, polytetrafluoroethylene, polyvinylidene fluoride, or a combination thereof can be used.

[0074] In the second layer, the binder may be included in an amount of, for example, 0.1 to 20 parts by weight relative to 100 parts by weight of amorphous carbon. The weight ratio may be a value calculated on a dry weight basis. In the second layer, the binder may be included in an amount of 0.5 parts by weight or more, 1 part by weight or more, 1.5 parts by weight or more, 2 parts by weight or more, 2.5 parts by weight or more, 3 parts by weight or more, 3.5 parts by weight or more, 4 parts by weight or more, 4.5 parts by weight or more, 5 parts by weight or more, 5.5 parts by weight or more, 6 parts by weight or more, 6.5 parts by weight or more, 7 parts by weight or more, 7.5 parts by weight or more, 8 parts by weight or more, 8.5 parts by weight or more, or 9 parts by weight or more, or 18 parts by weight or less, 16 parts by weight or less, 14 parts by weight or less, 12 parts by weight or less, or 10 parts by weight or less, based on 100 parts by weight of the amorphous carbon.

[0075] The second layer may further include, for example, 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., but is not limited thereto, and any element capable of forming an alloy with lithium in the art may be used.

[0076] The negative electrode assembly of the present invention may be characterized by further including a third layer positioned between the first layer and the second layer and including a lithium-friendly material.

[0077] The lithium-friendly material is a material capable of forming a compound or alloy with lithium, and may include at least one selected from the group consisting of Al, Ag, SiO2, Si3N4, Ni, Au, Cr, Cu, Ti, Pt, TiW, TiN, Sn, W, Al2O3, AlN, and InAl, but is not limited thereto.

[0078] The third layer may be formed on the first layer and / or the second layer by a deposition method, but is not limited thereto. The deposition method may utilize a known deposition method, but is not limited thereto.

[0079] The thickness of the third layer may be characterized as being 10 nm to 990 nm. The thickness may be measured, for example, by SEM, but is not limited thereto. The thickness of the third layer is, in other examples, 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, 100 nm or more, 110 nm or more, 120 nm or more, 130 nm or more, 140 nm or more, 150 nm or more, 160 nm or more, 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 950 nm or less, 900 nm or less, 850 nm or less, 800 nm or less, 750 nm or less, 700 nm or less, 650 nm or less, 600 nm or less, 550 nm or less, 500 nm or less, 450 nm or less, It may be 400 nm or less, 350 nm or less, or 300 nm or less. By controlling the thickness of the third layer within the above range, an all-solid-state battery with high charge / discharge efficiency and capacity retention rate can be provided.

[0080] The second layer may further comprise a lithium-affinity material. The lithium-affinity material may be described in the same manner as the lithium-affinity material described above. The lithium-affinity material included in the second layer may be identical to, or different from, the lithium-affinity material included in the third layer.

[0081] The negative electrode assembly of the present invention may further include, for example, a thin film including an element capable of forming an alloy with lithium. The thin film may be included between the negative electrode current collector and the coating layer, on a surface of the coating layer opposite to the solid electrolyte layer among both surfaces of the coating layer, and / or between the first layer and the second layer within the coating layer. The element capable of forming an alloy with lithium included in the thin film may include one of the examples described above, or may be composed of multiple types of alloys.

[0082] The thickness of the above thin film may be, for example, 1 to 800 nm, 10 to 700 nm, 50 to 600 nm, or 100 to 500 nm. The above thin film may be formed by, for example, a vacuum deposition method, a sputtering method, a plating method, etc., but is not limited thereto, and any method capable of forming a thin film in the relevant technical field may be used.

[0083] As the negative electrode current collector of the present invention, a known metal that can be used as a current collector of an all-solid-state battery can be used. The negative electrode current collector can be, for example, a material that does not form an alloy or compound with lithium. The negative electrode current collector can be, for example, selected from the group consisting of 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 (SUS), but is not limited thereto, and any metal that is used as an electrode current collector in the relevant technical field can be used as long as it does not impede the purpose of the present invention. The negative electrode current collector can be composed of one kind of the above-mentioned metal, or can be composed of an alloy or a coating material of two or more kinds of metals. The negative electrode current collector may be, for example, in the form of a plate, mesh, or foil, but is not limited thereto. The thickness of the negative electrode current collector may be, for example, in the form of 1 μm to 50 μm, but is not limited thereto.

[0084] The negative electrode assembly of the present invention may further include a metal and / or a metal layer thereof (also referred to herein as “lithium (alloy)” or “lithium (alloy) layer”) including lithium or a lithium alloy, for example, between the negative electrode current collector and the coating layer, between the coating layer and the solid electrolyte layer, or between the first layer, the second layer, and / or the first layer and the second layer constituting the coating layer, by charging. The lithium alloy may include, but is not limited to, 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, and any lithium alloy used in the art may be used. The lithium (alloy) or lithium (alloy) layer formed or included between the negative electrode current collector and the coating layer, between the coating layer and the solid electrolyte layer, between the first layer, the second layer and / or between the first layer and the second layer constituting the coating layer, etc. may be composed of one or more of these alloys, or lithium.

[0085] The negative electrode assembly of the present invention may further include a lithium (alloy) or lithium (alloy) layer between, for example, the negative electrode current collector and the solid electrolyte layer, for example, between the first layer and the second layer, by charging. In the present invention, although the mechanism is not clearly known, when lithium diffused toward the negative electrode during charging passes through the second layer, or when lithium is absorbed in the second layer and exceeds the charge capacity, lithium may be precipitated between the first layer and the second layer to form a lithium (alloy) layer. At this time, in the present invention, the second layer not only functions as a protective layer that suppresses side reactions and short circuits between lithium and the solid electrolyte layer described later, but also, due to its lithium-friendly characteristics, enables lithium to be plated more stably between the first layer and the second layer, thereby contributing to the formation of a more uniform and dense metal layer between the first layer and the second layer during the charging process. Accordingly, an all-solid-state battery to which the cathode assembly of the present invention is applied can achieve excellent charge / discharge efficiency and capacity retention rate.

[0086] The thickness of the lithium (alloy) layer may be, for example, in the range of 1 μm to 1000 μm, 1 μm to 500 μm, 1 μm to 200 μm, 1 μm to 150 μm, 1 μm to 100 μm, or 1 μm to 50 μm. The thickness needs to be controlled as described above so that the lithium (alloy) layer can perform its role as a lithium storage well and improve cycle characteristics.

[0087] The region between the negative electrode current collector and the coating layer, between the coating layer and the solid electrolyte layer, between the first layer, the second layer, and / or the first layer and the second layer constituting the coating layer, etc. may be a lithium-free region that does not contain lithium, for example, in the initial state or post-discharge state of the all-solid-state battery.

[0088] A second aspect of the present invention relates to an all-solid-state battery.

[0089] Matters relating to the first aspect and / or the second aspect of the present invention may be equally applied to matters relating to the third aspect unless specifically stated otherwise.

[0090] In this specification, “all-solid-state battery” may mean an all-solid-state secondary battery, and may also be referred to as a cell, secondary battery, or battery.

[0091] The above-mentioned all-solid-state battery may be characterized by including a positive electrode, a solid electrolyte layer, and / or the negative electrode assembly.

[0092] At this time, the all-solid-state battery may be characterized by including an anode-free all-solid-state battery that uses lithium or a lithium alloy as an anode active material. The anode-free all-solid-state battery may include an anode-free region in which a separate anode active material layer is not formed on an anode current collector during the battery manufacturing process, and may mean an all-solid-state battery in which lithium (or a lithium alloy) that functions as an anode active material during a charging process is formed on the anode current collector.

[0093] The positive electrode may include, for example, a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector. The positive electrode active material layer may be characterized by including, for example, at least one positive electrode active material selected from the group consisting of lithium transition metal oxides, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, and vanadium oxide. The lithium transition metal oxide may be lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, or lithium iron phosphate, or a combination thereof. The positive electrode active material is not limited thereto, and any positive electrode active material used in the art may be used. The positive electrode active materials may be used alone or in combination of two or more.

[0094] The above 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 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 D 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 Co b B c D α (In the above formula, 0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); Lia 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 Mn2G b O4 (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 dGeO2 (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 b O2 (in the above formula, 0.90≤a≤1, 0.001≤b≤0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiIO2; LiNiVO4; Li (3- f) J2(PO4)3(0≤f≤2); Li (3-f) Fe2(PO4)3(0≤f≤2); It may be a compound represented by any one of the chemical formulas of LiFePO4. In this 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 may be V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0095] The above-mentioned positive electrode active material may use a compound having a positive electrode coating layer added to at least a portion of the surface of the above-mentioned positive electrode active material, or may use a mixture of the above-mentioned compound and a compound having a positive electrode coating layer added. The positive electrode 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, Li3PO4, etc., but are not limited thereto. The compound forming the positive electrode coating layer may be amorphous or crystalline. The method for forming the positive electrode coating layer may include, for example, spray coating, dipping, etc., but may be selected without limitation within a range that does not adversely affect the properties of the positive electrode active material.

[0096] When the above-mentioned positive electrode active material is a ternary lithium transition metal oxide such as NCA or NCM and contains nickel (Ni), it may be possible to increase the capacity density of the all-solid-state battery and reduce metal dissolution of the positive electrode active material in a charged state. Accordingly, the cycle characteristics of the all-solid-state battery in a charged state may be improved.

[0097] The shape of the positive electrode active material may be, for example, a spherical particle shape, such as an elliptical sphere. The particle size of the positive electrode active material is not particularly limited and may be within the range applicable to positive electrode active materials of conventional all-solid-state secondary batteries. The content of the positive electrode active material is also not particularly limited and may be within the range applicable to positive electrodes of conventional all-solid-state secondary batteries.

[0098] The above positive electrode active material layer may further include, for example, a solid electrolyte, a binder, and / or a conductive material.

[0099] The solid electrolyte included in the positive electrode active material layer may be, for example, the same as or different from the solid electrolyte included in the solid electrolyte layer described below. The solid electrolyte included in the positive electrode active material layer may be, for example, an inorganic electrolyte such as a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a phosphate-based solid electrolyte, a halide-based solid electrolyte, or a polymer electrolyte, but is not limited thereto, and may be any electrolyte commonly used in all-solid-state batteries.

[0100] The solid electrolyte included in the positive electrode active material layer may have, for example, a smaller average particle size than the solid electrolyte included in the solid electrolyte layer. For example, the average particle size of the solid electrolyte included 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 included in the solid electrolyte layer.

[0101] The binder included in the above-described positive electrode active material layer may be, for example, at least one selected from acrylonitrile butadiene rubber (ABR), butadiene rubber (BR), styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited thereto.

[0102] The conductive material included in the above-described positive electrode active material layer may be characterized by being at least one selected from the group consisting of, for example, graphite; carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; or carbon fiber.

[0103] In addition to the above-mentioned positive electrode active material layer, the positive electrode active material layer may further include additives such as fillers, coating agents, dispersants, or ion conductive assistants, and these additives may be used without limitation as long as they are known materials generally used in electrodes of all-solid-state batteries.

[0104] The above-described positive electrode may further include, for example, a positive electrode current collector. The positive electrode current collector may be a known metal usable as a current collector of an all-solid-state battery. The positive electrode current collector may be, for example, 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.

[0105] In addition to the aforementioned configuration, the above-mentioned positive electrode may further include known configurations that can be included in the positive electrode in an all-solid-state battery.

[0106] The solid electrolyte layer may include, for example, one or more of the solid electrolytes that may be included in the aforementioned positive electrode active material layer. From the perspective of achieving excellent ionic conductivity and high energy density, the solid electrolyte layer may be characterized by including, for example, a sulfide-based solid electrolyte.

[0107] The above sulfide-based solid electrolyte is, 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, Li2S-SiS2-Li p MO q (p, 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, n are positive numbers), Z is one of Ge, Zn or Ga, Li2S-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 (0≤x≤2) may be at least one selected from. The sulfide-based solid electrolyte may be manufactured by treating starting materials such as Li2S and P2S5 by a melting rapid cooling method or a mechanical milling method. In addition, heat treatment may be performed after the treatment. The solid electrolyte may be in an amorphous, crystalline, or mixed state thereof. In the present invention, the sulfide-based solid electrolyte may be, for example, one including sulfur (S), phosphorus (P), and lithium (Li) as at least constituent elements among the above-mentioned sulfide-based solid electrolyte materials.

[0108] The above 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 It may be an argyrodite-type compound including at least one selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0109] The density of the above-mentioned argyrodite-type solid electrolyte may be, for example, 1.5 to 2.0 g / cc. Since the above-mentioned argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state secondary battery is reduced, and penetration of the solid electrolyte by Li can be effectively suppressed.

[0110] The above-described solid electrolyte layer may include, for example, 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 thereto, and any binder used in the art may be used. The binder included in the solid electrolyte layer may be the same as or different from the binder included in the above-described positive electrode active material layer and / or coating layer.

[0111] The solid electrolyte layer may be characterized by, for example, a thickness of 10 μm to 100 μm. In other examples, the solid electrolyte layer may have a thickness of, but is not limited to, 20 μm or more, 30 μm or more, or 40 μm or more, 90 μm or less, 80 μm or less, 70 μm or less, or 60 μm or less.

[0112] The all-solid-state battery of the present invention may be characterized by a charge / discharge efficiency of 90% or more. The charge / discharge efficiency may be evaluated according to the evaluation example described below. In other examples, the all-solid-state battery of the present invention may have a charge / discharge efficiency of 91% or more or 92% or more, and although the upper limit is not particularly limited, it may be 100% or less or 95% or less.

[0113] The all-solid-state battery of the present invention may be characterized by a capacity retention rate of 80% or more after 50 cycles. In the present specification, the capacity retention rate after 50 cycles may be evaluated in a manner according to an evaluation example described below. In another example, the all-solid-state battery of the present invention may have a capacity retention rate after 50 cycles of 81% or more, 82% or more, 83% or more, 84% or more, 85% or more, 86% or more, 87% or more, 88% or more, 89% or more, 90% or more, 91% or more, 92% or more, 93% or more, 94% or more, 95% or more, or 96% or more, or 100% or less, 99% or less, 98% or less, or 97% or less.

[0114] The all-solid-state battery of the present invention may be characterized by a specific capacity of 150 mAh / g or more after 50 cycles. In the present specification, the specific capacity after 50 cycles may be evaluated in a manner according to an evaluation example described below. In other examples, the all-solid-state battery of the present invention may have a specific capacity after 50 cycles of 155 mAh / g or more, 160 mAh / g or more, or 165 mAh / g or more, or 300 mAh / g or less, 250 mAh / g or less, or 200 mAh / g or less.

[0115] A third aspect of the present invention relates to a method for manufacturing a cathode assembly.

[0116] Matters relating to the first and second aspects of the present invention may be equally applied to matters relating to the third aspect unless specifically stated otherwise.

[0117] The method for manufacturing the negative electrode assembly of the present invention is a method for manufacturing the negative electrode assembly, which comprises forming a first layer and a second layer on a negative electrode current collector, wherein the first layer comprises LiX, wherein X is a halogen element, and the second layer may comprise amorphous carbon.

[0118] The method for forming the first layer and the second layer on the negative electrode collector can be applied without limitation as long as it is a known method for forming a thin film on the negative electrode collector.

[0119] For example, a method for forming the first layer and the second layer on the negative electrode current collector may include at least one method selected from direct gravure coating, micro gravure coating, slot die coating, coma coating, gravure coating, bar coating, roll coating, slide coating, evaporation deposition, chemical vapor deposition (CVD), and physical vapor deposition, but any method commonly known in the art may be applied without limitation.

[0120] Specifically, the method for manufacturing the negative electrode assembly may include a step of forming a first layer including LiX on the negative electrode current collector; and a step of forming a second layer including amorphous carbon on the first layer; wherein X may include a halogen element.

[0121] As another example, forming the first layer on the negative electrode current collector can be performed through deposition. The deposition can be selected from, for example, evaporation deposition, chemical vapor deposition (CVD), and physical vapor deposition, but is not limited thereto, and various deposition methods used in the relevant field can be used.

[0122] The present invention can contribute to improving the energy density of an all-solid-state battery by forming the first layer on the negative electrode current collector by depositing the first layer as described above, thereby forming the thickness of the first layer thinly within a predetermined range or less, and can also improve charge / discharge efficiency and capacity retention rate by not including any other composition other than LiX.

[0123] The step of forming a second layer containing amorphous carbon on the first layer may be characterized by including, for example, a step of applying a slurry containing amorphous carbon onto the first layer and / or a step of drying the slurry.

[0124] The above slurry may be characterized by further including, for example, a binder. The binder contained in the slurry may be identically applied to the binder contained in the second layer of the first aspect described above.

[0125] The slurry may further comprise, for example, an element capable of forming an alloy with lithium.

[0126] The above slurry may be characterized by further including, for example, a solvent. The solvent may be, but is not limited to, water, N-methylpyrrolidone (NMP), etc. The solvent may be evaporated during the drying step, and thus may not be included in the second layer formed in the final state, or may be included in a very small amount.

[0127] The above application may be performed by, but is not limited to, direct gravure coating, micro gravure coating, slot die coating, coma coating, gravure coating, bar coating, roll coating or slide coating, for example, and may be performed by a method commonly known in the art.

[0128] The drying step may be characterized by including, for example, a first drying step and / or a second drying step.

[0129] The above first drying step can be performed, for example, in air.

[0130] The first drying step may be performed at a temperature of, for example, 60°C to 100°C. In other examples, the first drying step may be performed at a temperature of 70°C to 90°C or a temperature of 75°C to 85°C.

[0131] The first drying step may be performed for, for example, 10 to 30 minutes. In another example, the first drying step may be performed for 15 to 25 minutes.

[0132] The second drying step may be performed, for example, under vacuum conditions.

[0133] The second drying step may be performed at a temperature of, for example, 80°C to 120°C. In other examples, the second drying step may be performed at a temperature of 90°C to 110°C or a temperature of 95°C to 105°C.

[0134] The second drying step may be performed for, for example, 10 to 15 hours. In another example, the second drying step may be performed for 11 to 13 hours.

[0135] Hereinafter, the present invention will be described in detail by way of examples to specifically illustrate the disclosure of the present invention and its intended functions and effects, as described above. However, these examples may be modified in various ways, and the scope of this specification is not construed as being limited to these examples. It is emphasized that these examples are provided to represent the present invention and to provide a more concrete explanation to those skilled in the art.

[0136] Example.

[0137] LiF was deposited to a thickness of 250 nm on a SUS foil having a thickness of 10 μm using equipment. Next, 6 g of carbon black (average particle size of 41 nm, BET surface area of ​​51 m2 / g), 9.33 g of PVDF solution (solid content 6%), and 7.19 g of NMP solution were placed in a thinky mixer container and mixed 12 times for 3 minutes at 2000 rpm, and then 5 g of NMP solution was additionally added and mixed 5 times for 3 minutes at 2000 rpm to prepare a slurry. Then, the slurry was coated on the LiF deposition layer (the side opposite to the side in contact with the SUS foil) using a bar coater, dried in air at 80°C for 20 minutes, and then vacuum dried at 100°C for 12 hours.

[0138] Through this, a cathode assembly was obtained in which a 250 nm thick LiF deposition layer (first layer) and a 10 ㎛ thick amorphous carbon-containing layer (second layer) were formed on a SUS foil.

[0139] (anode)

[0140] LiNi as positive electrode active material 0.8 Co 0.15 Mn 0.05 O2(NCM), Li6PS5Cl as a solid electrolyte in the form of argyrodite crystals, carbon nanofibers (CNF) as a conductive material, and polytetrafluoroethylene (Teflon binder, DuPont) as a binder were prepared. These materials were then mixed in a weight ratio of positive electrode active material: solid electrolyte: conductive material: binder = 84:15:0.2:1.2, and then formed into a large sheet shape to produce a positive electrode sheet. Subsequently, the positive electrode sheet was pressed onto an 18 ㎛ thick aluminum foil to produce a positive electrode.

[0141] The initial charge capacity (charge capacity at the first cycle) of the manufactured positive electrode was approximately 20 mAh at 4.25 V charge, and the positive electrode weight was approximately 110 mg (approximately 203 mAh / g per active material weight).

[0142] (solid electrolyte layer)

[0143] A solid electrolyte layer containing Li6PS5Cl was used.

[0144] (all-solid-state battery)

[0145] The above-described positive electrode, solid electrolyte layer, and negative electrode assembly were laminated and sealed in a pouch under vacuum to fabricate an all-solid-state battery. The solid electrolyte layer had a thickness of 50 μm. Meanwhile, to maintain vacuum in the battery, each portion of the positive and negative electrode collectors was allowed to protrude outside the pouch, and these protrusions were used as positive and negative terminals. The all-solid-state battery was then subjected to a hydrostatic treatment at 500 MPa for 30 minutes. By performing this hydrostatic treatment, the battery characteristics were significantly improved.

[0146] Comparative Example 1.

[0147] An all-solid-state battery was obtained in the same manner as in the above example, except that the first layer was not formed when manufacturing the non-cathode coating layer.

[0148] Comparative Example 2.

[0149] An all-solid-state battery was obtained in the same manner as in the above example, except that the second layer was not formed when manufacturing the non-cathode coating layer.

[0150] Comparative Example 3.

[0151] In manufacturing the cathode-free coating layer, an all-solid-state battery was obtained in the same manner as in the example, except that a slurry of LiF powder and PVDF mixed in a weight ratio of 95:5 was coated on a SUS foil having a thickness of 10 μm using a bar coater instead of deposition to form the first layer.

[0152] Evaluation example. Mini monocell cycle characteristics

[0153] The all-solid-state batteries (pouch-type monocells) of the above examples and comparative examples 1 to 3 were driven under the following charge / discharge conditions at an operating voltage range of 4.25 V to 3.0 V and an operating temperature of 45°C to evaluate the charge / discharge characteristics, and the results are shown in Table 1 and Figures 1 to 3 below.

[0154] Charging conditions: 0.1C, 4.25V CC / CV, 0.05C cut-off

[0155] Discharge conditions: 0.1C, 3.0V, CC

[0156] Classification Charge capacity (mAh / g) Discharge capacity (mAh / g) Efficiency (%) *Example 2 12.5 195.99 2.2 Comparative example 1 213.8 188.88 8.3 Comparative example 2**---Comparative example 3 269.1 159.5 59.3

[0157] * The above efficiency refers to the percentage ratio of discharge capacity to charge capacity.

[0158] ** Comparative Example 2 was unable to be measured due to a short circuit occurring during the charging process.

[0159]

[0160] In addition, the all-solid-state batteries (pouch-type monocells) of Examples and Comparative Examples 1 to 3 were driven under the following charge and discharge conditions at the same operating voltage range and operating temperature to evaluate the 50-cycle specific capacity and capacity retention rate, and the results are shown in Table 2, Figures 4 and 5 below.

[0161] Charging conditions: 0.33C, 4.25V CC / CV, 0.1C cut-off

[0162] Discharge conditions: 0.33C, 3.0V, CC

[0163] Classification 50 Cycle Capacity Retention Rate (%) Example 96.9 Comparative Example 179.3 Comparative Example 2*- Comparative Example 3**-

[0164] *Comparative Example 2 was unable to be measured due to a short circuit occurring during the charging process of the first cycle.

[0165] **Comparative Example 3 was unable to be measured due to a short circuit occurring during the charging process of the second cycle.

[0166]

[0167] As a result, it was confirmed that the charging and discharging efficiency of the first cycle was higher in the embodiment than in the comparative example, and the specific capacity and capacity retention rate according to the cycle were also excellent. Specifically, the embodiment showed an efficiency of 92.2% in the first cycle, a specific capacity of 150 mAh / g or more after 50 cycles, and a capacity retention rate of 96.9% after 50 cycles.

Claims

1. A negative electrode assembly comprising a first layer comprising LiX; a second layer comprising amorphous carbon; and a negative electrode current collector; wherein X is a halogen element.

2. A cathode assembly according to claim 1, characterized in that the first layer is essentially composed of LiX.

3. A cathode assembly according to claim 1, characterized in that the first layer contains 96 wt% or more of the LiX based on the total weight of the first layer.

4. A negative electrode assembly, characterized in that the first layer is closer to the negative electrode current collector than the second layer in the first paragraph.

5. A cathode assembly according to claim 1, characterized in that the thickness of the first layer is 10 nm to 990 nm.

6. A cathode assembly according to claim 1, characterized in that the thickness of the second layer is 1 ㎛ to 50 ㎛.

7. A cathode assembly, characterized in that the ratio of the thickness of the second layer to the thickness of the first layer in the first paragraph is 10 to 200.

8. A cathode assembly according to claim 1, characterized in that the LiX is LiF or LiCl.

9. A cathode assembly according to claim 1, characterized in that the amorphous carbon is at least one selected from the group consisting of carbon black, acetylene black, furnace black, Ketjen black, and graphene.

10. A cathode assembly according to claim 1, characterized in that the second layer further includes a binder.

11. A negative electrode assembly according to claim 1, characterized in that it further comprises a third layer located between the first layer and the second layer and containing a lithium-friendly material.

12. A cathode assembly according to claim 11, characterized in that the thickness of the third layer is 10 nm to 990 nm.

13. A negative electrode assembly according to claim 1, characterized in that the second layer further comprises a lithium-friendly material.

14. An all-solid-state battery comprising a positive electrode, a solid electrolyte layer, and a negative electrode assembly according to any one of claims 1 to 13.

15. An all-solid-state battery according to claim 14, characterized in that the all-solid-state battery is a non-anode all-solid-state battery using lithium or a lithium alloy as an anode active material.

16. An all-solid-state battery according to claim 14, characterized in that the solid electrolyte layer comprises a sulfide-based solid electrolyte.

17. In the 15th paragraph, the sulfide-based solid electrolyte is 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, Li2S-SiS2-Li p MO q (p, 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, n are positive numbers), Z is one of Ge, Zn or Ga, Li2S-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 An all-solid-state battery characterized by having at least one selected from (0≤x≤2).

18. An all-solid-state battery according to claim 14, characterized in that the charge / discharge efficiency is 90% or higher.

19. An all-solid-state battery characterized in that the capacity retention rate after 50 cycles is 90% or more in the 14th paragraph.

20. A method for manufacturing a cathode assembly, which forms a first layer and a second layer on a cathode current collector, The first layer above comprises LiX, wherein X is a halogen element, The above second layer is a method for manufacturing a cathode assembly including amorphous carbon.

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