Method for manufacturing thin film layer for all-solid-state battery and all-solid-state battery comprising thin film layer manufactured thereby

Abstract

The present invention relates to a method for manufacturing a thin film layer for an all-solid-state battery and an all-solid-state battery comprising a thin film layer manufactured thereby. Specifically, a thin film layer comprising a transition metal chalcogenide can be formed on a negative electrode current collector by using organic chemical vapor deposition. In the all-solid-state battery, the thin film layer can exhibit high lithium affinity and form a robust SEI layer, thereby improving the performance and durability of the battery.

Description

Method for manufacturing a thin film layer for an all-solid-state battery and an all-solid-state battery including a thin film layer manufactured according to the same

[0001] The present invention relates to a method for manufacturing a thin film layer for an all-solid-state battery and an all-solid-state battery comprising a thin film layer manufactured according to the same. Specifically, the invention relates to a method for forming a thin film layer on a negative electrode current collector using an organic chemical vapor deposition method.

[0002] With the development of various energy-related industries, such as lithium-ion batteries, all-solid-state batteries are gaining attention for replacing conventional flammable liquid electrolytes due to improved safety. In particular, anode-free lithium-metal batteries, which combine solid-state technology with anode-free batteries to increase energy density, have recently been receiving significant interest. In this context, anode-free batteries do not utilize excess lithium and do not employ lithium foil as the anode, thereby simplifying the manufacturing process and reducing costs. Despite the potential of these all-solid-state anode-free batteries, their performance remains poor to date due to reactions between the deposited lithium metal and the electrolyte, or the uneven formation of lithium metal in the current collector (CC).

[0003] Accordingly, strategies are being proposed to improve the uniformity of deposited lithium and the stability of the battery by modifying the current collector, such as coating functional layers using various materials on the current collector or changing its shape, in order to improve battery performance.

[0004] The present invention aims to solve these problems by providing an all-solid-state battery comprising a lithium protective layer capable of uniformly depositing lithium metal on a current collector during the charging and discharging process of the battery.

[0005] The objectives of the present invention are not limited to those mentioned above. The objectives of the present invention will become more apparent from the following description and will be realized by the means and combinations thereof described in the claims.

[0006] According to one aspect of the present invention, a method for manufacturing a thin film layer for an all-solid-state battery can be provided, comprising the steps of preparing a substrate and forming a thin film layer on the substrate by reacting a transition metal precursor and a chalcogen precursor by chemical vapor deposition, wherein the thin film layer comprises a transition metal chalcogenide.

[0007] In one embodiment, the substrate may include at least one of Ni, Cu, Al, Ti, or SUS (Stainless steel).

[0008] In one embodiment, the transition metal precursor is MO a , (NH4) b MS c , (NH4) b MO d or M e (CO) f It may include a compound that appears as at least one of the following. Here, M is a transition metal, a is an integer from 1 to 4, b is an integer from 1 to 2, c is an integer from 1 to 3, d is an integer from 1 to 4, e is an integer from 1 to 2, and f is an integer from 1 to 8.

[0009] In one embodiment, the transition metal precursor is MoO3, (NH4)2MoS4, Mo(CO)6, (NH4)2WS4, W(CO)6, ReO3, NH4ReO4, It may include at least one of CuO, (NH4)2CuS2, (NH4)2CoS2, Co2(CO)8, ZnO, or (NH4)2ZnS2. Preferably, the transition metal precursor is MoO3, (NH4)2MoS4, Mo(CO)6, (NH4)2WS4, W(CO)6, ReO3, or It may include at least one of NH4ReO4.

[0010] In one embodiment, the chalcogen precursor may include gaseous hydrogen chalcogenide.

[0011] In one embodiment, the reaction may be carried out for 15 to 45 minutes.

[0012] In one embodiment, the reaction may be carried out at a temperature of 200°C to 350°C.

[0013] In one embodiment, the chalcogen precursor may be provided to a reaction chamber together with an inert gas.

[0014] In one embodiment, the transition metal chalcogenide may include at least one crystal structure among a 2H phase, a 1T phase, or a 3R phase. Preferably, the transition metal chalcogenide may include a crystal structure of the 2H phase.

[0015] In one embodiment, the transition metal chalcogenide may include a two-dimensional layered structure.

[0016] In one embodiment, the transition metal chalcogenide may include a vertical nanosheet structure.

[0017] In one embodiment, the transition metal chalcogenide is MA w It can be expressed as (M is a transition metal, A is a chalcogen element, and w is an integer from 1 to 3).

[0018] In one embodiment, the transition metal chalcogenide may include at least one of MoS2, WS2, ReS2, CuS, CoS2, or ZnS. Preferably, the transition metal chalcogenide may include at least one of MoS2, WS2, and ReS2.

[0019] According to another aspect of the present invention, an all-solid-state battery may be provided comprising a negative electrode current collector, a thin film layer located on the negative electrode current collector and manufactured by the manufacturing method, a solid electrolyte layer formed on the thin film layer, a positive electrode active material layer formed on the solid electrolyte layer, and a positive electrode current collector formed on the positive electrode active material layer.

[0020] In one embodiment, the lithium metal layer located between the thin film layer and the solid electrolyte layer in the charged state of the all-solid-state battery may be further included.

[0021] In one embodiment, after the initial charge of the all-solid-state battery, the thin film layer may include a lithium-chalcogen compound and a transition metal in the form of a metal.

[0022] According to the present invention, a thin film layer can be formed on a substrate by reacting a transition metal precursor and a chalcogen precursor using an organic chemical vapor deposition method. Since the thin film layer contains a transition metal chalcogenide, the thin film layer exhibits high lithium affinity in an all-solid-state battery and forms a robust SEI layer, thereby improving the performance and durability of the battery.

[0023] The effects of the present invention are not limited to those mentioned above. It should be understood that the effects of the present invention include all effects that can be inferred from the following description.

[0024] Figure 1 shows the structure of an all-solid-state battery prior to the first charge according to one embodiment.

[0025] FIG. 2 shows the charge state of an all-solid-state battery according to one embodiment.

[0026] FIG. 3 illustrates the process of manufacturing an all-solid-state anode-free battery according to one embodiment.

[0027] Figure 4 shows the results of scanning electron microscope images of thin film layers according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0028] Figure 5 shows the result of photographing the thin film layer according to Example 1 using a scanning electron microscope.

[0029] Figure 6 shows the results of Raman analysis for thin film layers according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0030] Figure 7 (a) shows a cross-section of an all-solid-state battery after charging with a thin film layer according to Comparative Example 1, captured by a scanning electron microscope, and shows each layer and its thickness; (b) shows the same cross-section mapped with EDS for the element Cl; and (c) shows the same cross-section mapped with EDS for the element Fe.

[0031] Figure 8(a) shows a cross-section of an all-solid-state battery with a thin film layer according to Example 1 after charging, captured by a scanning electron microscope, with each layer and its thickness indicated; (b) shows the same cross-section mapped with Cl element via EDS mapping; and (c) shows the same cross-section mapped with Fe element via EDS mapping.

[0032] Figure 9 shows the XRD analysis results for the states of the battery before initial charging, after charging, and after discharging, respectively, to which the thin film layer according to Comparative Example 1 and the thin film layer according to Example 1 are applied.

[0033] Figure 10 shows the Mo 3d XPS analysis results for the state of the battery with the thin film layer according to Example 1 before the first charge, after charging, and after discharging.

[0034] Figure 11 shows the S 2p XPS analysis results for the state of the battery with the thin film layer according to Example 1 before the first charge, after charging, and after discharging.

[0035] Figure 12 is intended to explain the charging process of a battery with a thin film layer applied according to Example 1.

[0036] FIG. 13 is a graph comparing the initial nucleation overpotential characteristics of all-solid-state batteries with thin film layers according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0037] FIG. 14 is a performance comparison graph of full-cell batteries with thin film layers applied according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0038] FIG. 15 is a graph showing the results of testing the battery performance according to cycles of all-solid-state batteries with thin film layers applied according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0039] The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the spirit of the invention is sufficiently conveyed to a person skilled in the art.

[0040] In describing each drawing, similar reference numerals have been used for similar components. In the attached drawings, the dimensions of the structures are depicted enlarged from their actual size for clarity of the invention. Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0041] In this specification, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "immediately above" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "immediately below" the other part, but also the case where there is another part in between.

[0042] Unless otherwise specified, all numbers, values, and / or expressions used herein to represent amounts of ingredients, reaction conditions, polymer compositions, and formulations should be understood to be modified by the term "approximately" in all cases, as these numbers are essentially approximations reflecting the various uncertainties of measurement that occur in obtaining these values ​​among other things. Furthermore, where numerical ranges are disclosed herein, such ranges are continuous and, unless otherwise indicated, include all values ​​from the minimum value of such range to the maximum value. Moreover, where such ranges refer to integers, they include all integers from the minimum value to the maximum value, unless otherwise indicated.

[0043] In this specification, where a range is described for a variable, it will be understood that the variable includes all values ​​within the described range, including the described endpoints of the range. For example, the range “5 to 10” will be understood to include not only the values ​​5, 6, 7, 8, 9, and 10, but also any sub-ranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., and any values ​​between integers valid for the category of the described range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, and 6.5 to 9. Also, for example, the range “10% to 30%” will be understood to include all integers including values ​​such as 10%, 11%, 12%, 13%, etc. and up to 30%, as well as any sub-range such as 10% to 15%, 12% to 18%, 20% to 30%, etc., and any value between valid integers within the stated range category such as 10.5%, 15.5%, 25.5%, etc.

[0044] In addition, unless specifically stated or evident, the term “about” as used herein may be understood within the range of tolerances customary in the art (e.g., within 2 standard deviations of the mean). “about” may be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the specified value.

[0045] Furthermore, as used herein, the terms “vehicle,” “automobile,” or other similar terms are understood to include general automobiles such as sports utility vehicles (SUVs), buses, trucks, and various commercial vehicles, as well as means of transportation such as trains, ships, and aircraft, and to include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). A hybrid vehicle as used herein refers to a vehicle equipped with two or more power sources (e.g., a gasoline-powered vehicle and an electric-powered vehicle).

[0046] Where a certain computational capability is required when performing any method or program in this specification, it may be understood that it is driven by a hardware device that includes memory and a processor and is specifically programmed to execute the method or program described in this specification. The memory is configured to store a module, and the processor is specifically configured to execute said module to perform one or more processes further described below.

[0047] Additionally, it may be implemented as a non-transient computer-readable medium containing executable program instructions executed by a processor, controller, etc. Examples of computer-readable media include, but are not limited to, ROM, RAM, Compact Disc (CD)-ROM, magnetic tape, floppy disk, flash drive, smart card, and optical data storage device. The computer-readable medium may also be distributed to computer systems connected to a network to be stored and executed in a distributed manner, such as a telematics server or a CAN (Controller Area Network).

[0048]

[0049] A method for manufacturing a thin film layer for an all-solid-state battery according to one embodiment of the present invention comprises the steps of preparing a substrate and forming a thin film layer on the substrate by reacting a transition metal precursor and a chalcogen precursor by chemical vapor deposition, wherein the thin film layer may include a transition metal chalcogenide.

[0050] Below, each step is explained in more detail.

[0051] First, a substrate for forming a thin film layer can be prepared. In one embodiment, the substrate may refer to a current collector applicable to an all-solid-state battery, and preferably may refer to a negative current collector. The substrate may include, for example, at least one of Ni, Cu, Al, Ti, or SUS (Stainless steel).

[0052] Next, a thin film layer can be formed on the substrate. In one embodiment, the thin film layer may be formed by chemical vapor deposition (CVD), and preferably by organic chemical vapor deposition.

[0053] Specifically, a transition metal precursor is transferred to a reaction chamber of a known apparatus capable of performing chemical vapor deposition. Here, the transition metal precursor may be transferred together with an inert gas serving as a carrier gas. Additionally, a gaseous chalcogen precursor may be introduced into the reaction chamber. In this case, the chalcogen precursor may be introduced in the form of a mixed gas together with the inert gas.

[0054] Next, the temperature inside the reaction chamber of the chemical vapor deposition apparatus can be increased to induce a reaction between the transition metal precursor and the chalcogen precursor. Through the reaction, a thin film layer containing a transition metal chalcogenide can be formed on a substrate.

[0055] In one embodiment, the transition metal precursor can be used without particular limitation as long as it is capable of reacting with the chalcogen precursor by the chemical vapor deposition method to form a transition metal chalcogenide, for example, the transition metal precursor is MO a , (NH4) b MS c , (NH4) b MO d or M e (CO) f It may include a compound that appears as at least one of the following. Here, M is a transition metal, a is an integer from 1 to 4, b is an integer from 1 to 2, c is an integer from 1 to 3, d is an integer from 1 to 4, e is an integer from 1 to 2, and f is an integer from 1 to 8.

[0056] In addition, in one embodiment, the transition metal precursor is MoO3, (NH4)2MoS4, Mo(CO)6, (NH4)2WS4, W(CO)6, ReO3, NH4ReO4, It may include at least one of CuO, (NH4)2CuS2, (NH4)2CoS2, Co2(CO)8, ZnO, or (NH4)2ZnS2. Preferably, the transition metal precursor is MoO3, (NH4)2MoS4, Mo(CO)6, (NH4)2WS4, W(CO)6, ReO3, or It may include at least one of NH4ReO4.

[0057] In one embodiment, the chalcogen precursor may include gaseous hydrogen chalcogenide. For example, the hydrogen chalcogenide includes at least one of hydrogen sulfide (H2S), hydrogen selenide (H2S), or hydrogen telluride (H2Te), and preferably, hydrogen sulfide (H2S) may be used.

[0058] In one embodiment, the reaction may be carried out for 10 minutes to 1 hour. Preferably, it may be carried out for 15 minutes to 45 minutes. More preferably, it may be carried out for 15 minutes to 30 minutes. According to one embodiment of the present invention, by controlling the reaction time of the transition metal precursor and the chalcogen precursor to an appropriate range, a thin film layer with a low initial nucleation overpotential, improved lithium affinity, and appropriate density and size can be formed.

[0059] In one embodiment, the reaction may be carried out at a temperature of 200°C to 350°C. Additionally, the reaction temperature may be 200°C or higher, 250°C or higher, 350°C or lower, 300°C or lower, or a value between the above numerical ranges.

[0060] In one embodiment, the inert gas mixed with the carrier gas, which is an inert gas or a chalcogen precursor, may include at least one of argon (Ar), helium (He), krypton (Kr), or nitrogen (N2), and the flow rate of the inert gas introduced into the reaction chamber is not specifically limited and can be set in various ways depending on the type of transition metal precursor and / or chalcogen precursor used, the thickness of the desired thin film layer, the reaction temperature, etc.

[0061] A thin film layer prepared according to one embodiment of the present invention may include a transition metal chalcogenide. In one embodiment, the transition metal chalcogenide may include at least one crystal structure among a 2H phase, a 1T phase, or a 3R phase. Preferably, the transition metal chalcogenide may include a crystal structure of the 2H phase. Additionally, the transition metal chalcogenide may include a two-dimensional layered structure.

[0062] Transition metal chalcogenides synthesized according to one embodiment of the present invention can exhibit excellent electrochemical reactivity and performance by having a crystal structure of at least one of a 2H phase, a 1T phase, or a 3R phase, particularly a 2H phase, and a two-dimensional layered structure. In addition, the interface characteristics between the solid electrolyte layer and the negative electrode current collector can be improved, and a lithium layer can be formed more uniformly during charging of the all-solid-state battery.

[0063] In one embodiment, the transition metal chalcogenide may include a vertical nanosheet structure. Additionally, the size of the vertical nanosheet may be 10 nm to 400 nm, and specifically, it may be 10 nm or more, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 50 nm or less, or a value between the above numerical ranges.

[0064] According to one embodiment of the present invention, the transition metal chalcogenide is formed to have a vertical nanosheet structure on the negative electrode current collector, thereby promoting the formation of a lithium-friendly thin film layer at the interface between the solid electrolyte layer and the negative electrode current collector. Furthermore, since the shape of the nanosheet can be controlled according to one embodiment of the present invention, the transition metal chalcogenide-based two-dimensional material can not only operate as an all-solid-state cathode-free battery but also possess excellent performance.

[0065] In one embodiment, the transition metal chalcogenide is MA w It can be represented as (M is a transition metal, A is a chalcogen element, and w is an integer from 1 to 3). The transition metal chalcogenide may include, for example, at least one of MoS2, WS2, ReS2, CuS, CoS2, or ZnS. Preferably, the transition metal chalcogenide may include at least one of MoS2, WS2, and ReS2.

[0066] According to another aspect of the present invention, an all-solid-state battery may be provided comprising a negative electrode current collector (10), a thin film layer located on the negative electrode current collector (10) and manufactured by the manufacturing method, a solid electrolyte layer formed on the thin film layer, a positive electrode active material layer formed on the solid electrolyte layer, and a positive electrode current collector formed on the positive electrode active material layer.

[0067] In one embodiment, the lithium metal layer (60) located between the thin film layer and the solid electrolyte layer in the charged state of the all-solid-state battery may be further included.

[0068] In one embodiment, after the initial charge of the all-solid-state battery, the thin film layer may include a lithium-chalcogen compound and a transition metal in the form of a metal.

[0069] In one embodiment, the thin film layer may have a thickness of 1 nm to 400 nm. Specifically, it may be 1 nm or more, 300 nm or less, 200 nm or less, 100 nm or less, 50 nm or less, or a value between the above numerical ranges.

[0070] FIG. 1 shows the structure of an all-solid-state battery prior to the first charging according to one embodiment. The all-solid-state battery according to FIG. 1 may include a negative electrode current collector (10), a thin film layer (20) located on the negative electrode current collector (10) and manufactured by the manufacturing method, a solid electrolyte layer (30) formed on the thin film layer (20), a positive electrode active material layer (40) formed on the solid electrolyte layer (30), and a positive electrode current collector (50) formed on the positive electrode active material layer (40).

[0071] The above-mentioned negative current collector (10) may be a plate-shaped substrate having electrical conductivity, and specifically, the above-mentioned negative current collector (10) may have the form of a sheet, a thin film, or a foil. The above-mentioned negative current collector (10) may include a material that does not react with lithium. Specifically, the above-mentioned negative current collector (10) may include at least one of Ni, Cu, Al, Ti, or SUS (Stainless steel).

[0072] The above thin film layer (20) contains a transition metal chalcogenide and is substantially the same as that described above, so a detailed description is omitted.

[0073] The solid electrolyte layer (30) is located between the thin film layer (20) and the positive active material layer (40) and is configured to facilitate the movement of lithium ions. The solid electrolyte layer (30) may include a solid electrolyte that is lithium ion conductive.

[0074] The above solid electrolyte may include at least one selected from the group consisting of oxide-based solid electrolytes, sulfide-based solid electrolytes, polymer electrolytes, and combinations thereof. However, it may be preferable to use a sulfide-based solid electrolyte with high lithium ion conductivity. The above sulfide-based solid electrolyte is not particularly limited, but includes Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-LiCl, Li2S-P2S5-LiBr, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, and Li2S-P2S5-Z m S n (where m and n are positive numbers, and Z is one of Ge, Zn, or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y(where x and y are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, or In), Li 10 GeP2S 12 It may be the same. Preferably, Li6PS5X having an azirodite structure (X=at least one of Cl, Br, and I) can be used as the solid electrolyte.

[0075] The above oxide-based solid electrolytes are perovskite-type LLTO (Li3xLa2 / 3-xTiO3) and phosphate-based NASICON-type LATP (Li 1+x Al x Ti 2-x It may include (PO4)3) etc.

[0076] The above polymer electrolyte may include gel polymer electrolytes, solid polymer electrolytes, etc.

[0077] The solid electrolyte layer (30) may further include a binder. The binder may include butadiene rubber, nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), etc.

[0078] The above positive active material layer (40) is configured to reversibly absorb and release lithium ions. The above positive active material layer (40) may include a positive active material, a solid electrolyte, a conductive material, a binder, etc.

[0079] The above positive active material may be an oxide active material or a sulfide active material.

[0080] The above oxide active materials are LiCoO2, LiMnO2, LiNiO2, LiVO2, and LiNi x Co y Mn 1-x-y O 2, Li 1+x Ni 1 / 3 Co 1 / 3 Mn 1 / 3 Rock salt layer type active materials such as O2, LiMn2O4, Li(Ni 0.5 Mn 1.5 Spinel-type active materials such as )O4, inverse spinel-type active materials such as LiNiVO4 and LiCoVO4, olivine-type active materials such as LiFePO4, LiMnPO4, LiCoPO4, and LiNiPO4, silicon-containing active materials such as Li2FeSiO4 and Li2MnSiO4, LiNi 0.8 Co (0.2-x) Al x A salt-layered active material in which some of the transition metals are replaced with heterogeneous metals, such as O2 (0<x<0.2), Li 1+x Mn 2-x-y M y Spinel-type active material in which a portion of the transition metal is substituted with a heterogeneous metal, such as O4 (M is at least one of Al, Mg, Co, Fe, Ni, Zn and 0 < x+y < 2), Li4Ti5O 12 It may be lithium titanate.

[0081] The above sulfide active material may be copper chevrell, iron sulfide, cobalt sulfide, nickel sulfide, etc.

[0082] The solid electrolyte included in the positive electrode active material layer (40) may be of the same type as that included in the solid electrolyte layer (30). Here, "same type" means that the type of compound that can be used as the solid electrolyte is the same, and it is not necessary to use the same type of compound.

[0083] The above conductive material may be carbon black, conducting graphite, acetylene black, carbon fiber, graphene, etc.

[0084] The binder may include butadiene rubber, nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), etc.

[0085] The above positive current collector (50) may be a plate-shaped substrate that is electrically conductive. Specifically, the above positive current collector (50) may have the form of a sheet or a thin film.

[0086] The above positive current collector (50) may include at least one selected from the group consisting of indium, copper, magnesium, aluminum, stainless steel, iron, and combinations thereof.

[0087] In one embodiment, the method of stacking or assembling the all-solid-state battery is not particularly limited, and for example, the negative current collector (10) on which the thin film layer (20) is formed, the solid electrolyte layer (30), the positive active material layer (40), and the positive current collector (50) can be assembled by a method such as a coin cell process or a pressurization process. As one embodiment, the battery may be assembled by applying a pressurization of 10-400 MPa using a pressurization device in a glove box in an inert gas environment.

[0088] In one embodiment, the all-solid-state battery according to one embodiment of the present invention may be a negative electrode all-solid-state battery that does not include a negative electrode active material layer. Here, not including a negative electrode active material layer can be understood as not forming a layer including a conventional graphite-based active material, silicon-based active material, etc. between the negative electrode current collector (10) and the solid electrolyte layer (30).

[0089] FIG. 2 shows the charge state of an all-solid-state battery according to one embodiment.

[0090] When charging the all-solid-state battery, the transition metal chalcogenide in the thin film layer (20) reacts with lithium ions, and at least a portion thereof may be converted into a lithium-chalcogen compound and a transition metal in the form of a metal. Accordingly, after the initial charging of the all-solid-state battery, the thin film layer (20') may contain a lithium-chalcogen compound and a transition metal in the form of a metal.

[0091] For example, if the transition metal chalcogenide is MoS2, it can be converted into the metallic form Mo and lithium sulfide (Li2S) by the initial charge. Consequently, after the initial charge of the all-solid-state battery, for example, the formation process, the thin film layer (20') may contain the metallic form Mo and lithium sulfide (Li2S).

[0092] In addition, when charging the all-solid-state battery, lithium ions that have moved through the solid electrolyte layer (30) onto the negative electrode current collector (10) can be uniformly deposited between the negative electrode current collector (10) and the thin film layer (20'). That is, in the charging state of the all-solid-state battery, a lithium metal layer (60) located between the thin film layer (20') and the solid electrolyte layer (30) may be further included.

[0093] In an all-solid-state battery according to one embodiment of the present invention, the thin film layer (20) containing the transition metal chalcogenide operates in this manner to form a solid electrolyte interphase (SEI) layer based on a lithium-chalcogen compound (e.g., Li2S) and an intermediate layer (20') based on a lithium-friendly transition metal (e.g., Mo), thereby improving the uniformity of lithium deposition. Accordingly, excellent all-solid-state battery performance and improved stability can be exhibited.

[0094] In one embodiment, the all-solid-state battery including the thin film layer (20) may be operated under operating pressure of 0.1 MPa or less and a temperature of 60°C or less.

[0095]

[0096] The present invention will be described in detail below with reference to the following examples and comparative examples. However, the technical scope of the present invention is not limited or restricted by this.

[0097]

[0098] Preparation Example - Preparation of a MoS2 thin film layer on a cathode current collector

[0099] A SUS sheet prepared as a cathode current collector was placed in a reaction chamber, and a transition metal precursor, Mo(CO)6, was transferred to the reaction chamber using an Ar carrier gas (50 SCCM) at 5°C. In the reaction chamber, a mixed gas of N2 + H2S (150 SCCM) was injected for 15 minutes at a pressure of 2 Torr, and the Mo(CO)6 was reacted with hydrogen sulfide at 260°C to directly grow a MoS2 layer having a vertical nanosheet structure on the cathode current collector.

[0100]

[0101] Example 1 - All-solid-state non-cathode battery including MoS2 thin film layer (15 min)

[0102] FIG. 3 illustrates the process of manufacturing an all-solid-state anode-free battery according to one embodiment. As shown in FIG. 3, Li6PS5Cl was synthesized using a conventional ball-milling method, and then 300 mg of Li6PS5Cl was subjected to a pressure of 400 MPa for 2 minutes to produce a pellet. Subsequently, 34 mg of a composite cathode material, in which NCM622 cathode active material and Li6PS5Cl were mixed, was placed on the cathode side and compressed at the same pressure. Then, a cathode current collector having a MoS2 thin film layer prepared in the above manufacturing example was placed on the cathode-side pellet on the opposite side and compressed at 140 MPa for 2 minutes to produce a sulfide-based all-solid-state anode-free battery structure.

[0103]

[0104] Example 2 - All-solid-state non-cathode battery including MoS2 thin film layer (45 min)

[0105] An all-solid-state anode-free battery was manufactured through the same process as in Example 1, except that a MoS2 thin film layer prepared by reacting Mo(CO)6 and hydrogen sulfide in the reaction chamber for 45 minutes was used in the manufacturing example.

[0106]

[0107] Comparative Example 1 - SUS Current Collector-Based All-Solid State Anode-Free Battery

[0108] The manufacturing process of the all-solid-state anode-free battery was performed in the same manner as in the example, and a pure SUS current collector substrate that had not undergone any treatment was used. The compression of Li6PS5Cl and the composite anode was carried out sequentially in the same manner as in Example 1, and finally, a SUS current collector was placed on the anode-side pellet and compressed to produce an all-solid-state anode-free battery.

[0109]

[0110] Comparative Example 2 - All-solid-state non-cathode battery including MoS2 thin film layer (3 min)

[0111] An all-solid-state anode-free battery was manufactured through the same process as in Example 1, except that a MoS2 thin film layer prepared by reacting Mo(CO)6 with hydrogen sulfide for 3 minutes in the reaction chamber was used in the manufacturing example.

[0112]

[0113] Experimental Example 1 - Analysis Test

[0114] Scanning electron microscopy (SEM, Hitachi S-4800) and high-resolution transmission electron microscopy (HRTEM; JEM-ARM200F, JEOL) were used to investigate the morphology of the thin film layers prepared according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2, and the results are shown in Fig. 4. In addition, the structure of the thin film layer according to Example 1 was investigated more specifically by photographing it with an SEM at different magnifications.

[0115] Referring to the results in Figures 4 and 5, it was confirmed that in the case of Example 1, MoS2 in the form of vertical nanosheets was formed on the cathode current collector, and it was confirmed that the size of the nanosheets changed according to the reaction time.

[0116] In addition, to confirm the structural characteristics of the thin film layers prepared according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2, the results of analysis using Raman spectroscopy (UniThink Inc., UR1207J) at an excitation wavelength of 532 nm are shown in Fig. 6. Referring to the results in Fig. 6, characteristic Raman peaks corresponding to MoS2 were observed under all conditions except Comparative Example 1.

[0117] The morphology of Li deposited after charging of the all-solid-state anode-free batteries prepared in Example 1 and Comparative Example 1 was investigated using SEM to SEM-EDS (energy dispersive spectroscopy) analysis. Figure 7 (a) shows a cross-section of an all-solid-state battery with a thin film layer according to Comparative Example 1 after charging, captured by scanning electron microscope, with each layer and its thickness indicated; (b) shows the same cross-section mapped with Cl element using EDS mapping; and (c) shows the same cross-section mapped with Fe element using EDS mapping.

[0118] In addition, Figure 8(a) shows a cross-section of an all-solid-state battery after charging with a thin film layer according to Example 1, captured by a scanning electron microscope, and shows each layer and its thickness; (b) shows the same cross-section mapped with EDS for the element Cl; and (c) shows the same cross-section mapped with EDS for the element Fe.

[0119] Referring to Figures 7 and 8, it was confirmed that the lithium deposited in the SEM image of Comparative Example 1 after charging had a non-uniform thickness and non-contact surface, whereas the lithium deposited in the SEM image of Example 1 had a uniform thickness and an increased average thickness, thereby improving the lithium storage capacity and uniformity.

[0120] Figure 9 shows the results of an evaluation using X-ray diffraction (XRD, Bruker D8 Discover, Bruker-AXS) to confirm the presence or absence of actual Li deposition before and after charging and discharging of the all-solid-state anode-free batteries prepared in Example 1 and Comparative Example 1.

[0121] In the XRD analysis results of Fig. 9, it was confirmed that in both Example 1 and Comparative Example 1, the Li metal peak was present and then disappeared after charging and discharging, thereby confirming that lithium metal is deposited and de-de-deposited during charging and discharging, and that the battery operates normally as a non-anode battery.

[0122] The results of analyzing the structural characteristics of the MoS2 material prepared in Example 1 in its original state, after charging, and after discharging of the all-solid-state battery using X-ray photoelectron spectroscopy (XPS; Thermo VG Scientific) were divided into those for Mo3d and S2p and are shown in Figures 10 and 11, respectively.

[0123] Referring to the results in Figures 10 and 11, in the original state, Mo and S peaks corresponding to the MoS2 material were present on the surface, whereas after charging, the peaks corresponding to the MoS2 semiconductor disappeared, and peaks corresponding to Mo metal and Li2S were confirmed.

[0124] This means that, as shown in Fig. 12, MoS2 undergoes a conversion reaction into Mo metal and Li2S during the charging process, and Li2S, which is known to form an excellent SEI layer, has excellent lithium affinity, and Li + The formation of an intermediate layer composed of Mo metal with high water absorption capacity implies interface stabilization and, through this, improved battery performance.

[0125]

[0126] Experimental Example 2 - All-solid-state anode-free battery test

[0127] The initial nucleation overpotential of the all-solid-state anode-free batteries prepared in Examples 1 and 2, and Comparative Example 1 and Comparative Example 2 was analyzed using an electrochemical analyzer under conditions of a driving pressure of 0.01 MPa and a temperature of 60°C, and the results are shown in Fig. 13. Referring to the results in Fig. 13, Examples 1 and 2 showed lower nucleation overpotentials than Comparative Example 1, confirming that lithium affinity was improved due to MoS2. In addition, lower overpotentials were observed when compared to Comparative Example 2, confirming that a MoS2 layer of appropriate size is optimal for lithium deposition by adjusting the reaction time.

[0128] Figure 14 is a performance comparison graph of full-cell batteries with thin film layers according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2. Referring to the results in Figure 14, it was confirmed that Example 1 and Example 2 not only showed significantly improved capacity and stability compared to Comparative Example 1, but also exhibited the best performance compared to Comparative Example 2, consistent with the nucleation overpotential trend. In particular, Example 1 was the best.

[0129] FIG. 15 is a graph showing the results of testing the battery performance according to cycles of all-solid-state batteries with thin film layers applied according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0130] Referring to the results in Fig. 15, it was confirmed that the Coulomb efficiency and durability of the all-solid-state batteries of Example 1 and Example 2 were superior to those of Comparative Example 1 and Comparative Example 2, and in particular, Example 1 was the most superior.

[0131]

[0132] From the above results, it can be confirmed that the method for manufacturing a transition metal chalcogenide-based two-dimensional semiconductor material according to various embodiments of the present invention can manufacture a two-dimensional semiconductor having a controllable nanosheet structure, and furthermore, by applying it to a cathode-free all-solid-state battery, it can provide a device exhibiting improved performance compared to a comparative example, and can also be optimized to achieve performance equivalent to that of the conventional method.

[0133]

[0134] Although embodiments of the present invention have been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention.

[0135]

[0136] 10: Cathode current collector

[0137] 20: Thin film layer

[0138] 20': Thin film layer after initial charging

[0139] 30: Solid electrolyte layer

[0140] 40: Positive active material layer

[0141] 50: Positive current collector

[0142] 60: Lithium metal layer

[0143]

[0144] The manufacturing method according to the present invention can form a thin film layer on a cathode current collector using an organic chemical vapor deposition method.

Claims

1. Step of preparing the substrate, The method includes the step of forming a thin film layer on the substrate by reacting a transition metal precursor and a chalcogen precursor using chemical vapor deposition; The above thin film layer comprises a transition metal chalcogenide, Method for manufacturing a thin film layer for all-solid-state batteries 2. In Paragraph 1, The above substrate comprises at least one of Ni, Cu, Al, Ti, or SUS (Stainless steel). Method for manufacturing a thin film layer for all-solid-state batteries 3. In Paragraph 1, The above transition metal precursor is MO a , (NH4) b MS c , (NH4) b MO d or M e (CO) f Compound comprising at least one of the following: (Here, M is a transition metal, a is an integer from 1 to 4, b is an integer from 1 to 2, c is an integer from 1 to 3, d is an integer from 1 to 4, e is an integer from 1 to 2, and f is an integer from 1 to 8) Method for manufacturing a thin film layer for all-solid-state batteries 4. In Paragraph 1, The above transition metal precursors are MoO3, (NH4)2MoS4, Mo(CO)6, (NH4)2WS4, W(CO)6, ReO3, NH4ReO4, Comprising at least one of CuO, (NH4)2CuS2, (NH4)2CoS2, Co2(CO)8, ZnO, or (NH4)2ZnS2, Method for manufacturing a thin film layer for all-solid-state batteries 5. In Paragraph 4, The above transition metal precursor is MoO3, (NH4)2MoS4, Mo(CO)6, (NH4)2WS4, W(CO)6, ReO3, or NH4ReO4, including at least one of, Method for manufacturing a thin film layer for all-solid-state batteries 6. In Paragraph 1, The above chalcogen precursor comprises gaseous hydrogen chalcogenide, Method for manufacturing a thin film layer for all-solid-state batteries 7. In Paragraph 1, The above reaction is performed for 15 to 45 minutes, Method for manufacturing a thin film layer for all-solid-state batteries 8. In Paragraph 1, The above reaction is carried out at a temperature of 200℃ to 350℃, Method for manufacturing a thin film layer for all-solid-state batteries 9. In Paragraph 1, The above chalcogen precursor is provided to a reaction chamber together with an inert gas, Method for manufacturing a thin film layer for all-solid-state batteries 10. In Paragraph 1, The above transition metal chalcogenide comprises a crystal structure of at least one of a 2H phase, a 1T phase, or a 3R phase, Method for manufacturing a thin film layer for all-solid-state batteries 11. In Paragraph 10, The above transition metal chalcogenide comprises a crystal structure of the 2H phase, Method for manufacturing a thin film layer for all-solid-state batteries 12. In Paragraph 1, The above transition metal chalcogenide comprises a two-dimensional layered structure, Method for manufacturing a thin film layer for all-solid-state batteries 13. In Paragraph 1, The above transition metal chalcogenides include a vertical nanosheet structure, Method for manufacturing a thin film layer for all-solid-state batteries 14. In Paragraph 1, The above transition metal chalcogenides are MA w Represented as (M is a transition metal, A is a chalcogen element, w is an integer from 1 to 3), Method for manufacturing a thin film layer for all-solid-state batteries 15. In Paragraph 1, The above transition metal chalcogenides are MoS2, WS2, ReS2, Comprising at least one of CuS, CoS2, or ZnS, Method for manufacturing a thin film layer for all-solid-state batteries 16. In Paragraph 15, The above transition metal chalcogenide comprises at least one of MoS2, WS2, and ReS2, Method for manufacturing a thin film layer for all-solid-state batteries 17. Cathode current collector; A thin film layer located on the above-mentioned cathode current collector and manufactured according to any one of claims 1 to 16; A solid electrolyte layer formed on the above thin film layer; A positive active material layer formed on the above solid electrolyte layer; and A positive current collector formed on the positive active material layer; comprising All-solid-state battery 18. In Paragraph 17, A lithium metal layer further comprising a thin film layer and a solid electrolyte layer located between the thin film layer and the solid electrolyte layer in the charged state of the above-mentioned all-solid-state battery All-solid-state battery 19. In Paragraph 17, After the initial charge of the above-mentioned all-solid-state battery, the thin film layer comprises a lithium-chalcogen compound and a transition metal in metallic form, All-solid-state battery

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