Method for manufacturing All Solid-State Battery

Abstract

The present invention provides a method for manufacturing an all-solid-state battery, comprising: a coating step in which a lubricating material is coated onto a positive electrode active material powder; a mixture forming step in which a mixture is formed by mixing the positive electrode active material powder coated with the lubricating material and an electrolyte powder; a coating step in which the mixture is applied onto a positive electrode current collector; and a compression step in which the mixture and the positive electrode current collector are compressed against each other. According to the present invention, voids within the anode composite layer formed in the compression step can be reduced, and the performance of the all-solid-state battery can be improved.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing an all-solid-state battery, and specifically, to a method for manufacturing an all-solid-state battery capable of reducing the void between a positive electrode active material (e.g., positive electrode active material powder) and an electrolyte (e.g., electrolyte powder). Background Technology

[0002] A solid-state battery refers to a battery in which the electrolyte between the positive and negative electrodes is replaced from the conventional liquid to a solid.

[0003] In conventional batteries where the electrolyte is liquid, there is a risk of fire if the positive and negative electrodes come into contact. However, since all-solid-state batteries use a solid electrolyte through which lithium ions move, the electrolyte and electrodes remain fixed, allowing them to operate normally without being damaged or exploding even in the event of external disturbances.

[0004] For example, Korean Patent Publication No. 10-2016-0060171 (hereinafter referred to as the "prior art document") discloses an all-solid-state battery that does not contain a binder and discloses a method of injecting an active material in the form of a slurry into the voids of a carbon structure included in a positive electrode.

[0005] The invention disclosed in these prior art documents does not consider voids formed within a cathode composite, which is a composite of a cathode active material powder and an electrolyte powder formed by the compression of the cathode active material powder and the electrolyte powder.

[0006] In addition, the invention disclosed in the prior art literature requires a process of injecting an active material in the form of a slurry into an anode in which a void has already been formed, and a process of drying the injected active material. These processes have the problem of reducing the mass production efficiency of all-solid-state batteries.

[0007] In addition, the invention disclosed in the prior art has a problem in that the density of the electrolyte mixed in the anode is reduced, which consequently can lead to a decrease in the performance of the all-solid-state battery. Prior art literature

[0008] Korean Patent Publication No. 10-2016-0060171 The problem to be solved

[0009] The present invention aims to solve the aforementioned problem by providing a method for manufacturing an all-solid-state battery capable of reducing voids within a cathode composite formed by the compression of a positive electrode active material powder and an electrolyte powder.

[0010] In addition, the present invention aims to provide a method for manufacturing an all-solid-state battery that can reduce resistance within the all-solid-state battery and improve the performance of the all-solid-state battery by reducing pores within the anode composite.

[0011] In addition, the present invention aims to provide a method for manufacturing an all-solid-state battery that can improve the mass production capability of the all-solid-state battery. means of solving the problem

[0012] The present invention, for achieving the aforementioned objectives, provides a method for manufacturing an all-solid-state battery comprising: a coating step in which a lubricating material is coated onto a positive electrode active material powder; a mixture forming step in which a mixture is formed by mixing the positive electrode active material powder coated with the lubricating material and an electrolyte powder; a coating step in which the mixture is applied onto a positive electrode current collector; and a compression step in which the mixture and the positive electrode current collector are compressed against each other.

[0013] According to the present invention, voids within an anode composite formed by mixing and compressing an anode active material powder and an electrolyte powder can be reduced by the lubricating material. That is, according to the present invention, the mobility (degree of freedom of movement) of the electrolyte powder within the anode composite can be improved. Furthermore, since it is sufficient to simply compress the anode active material powder, which is pre-coated with the lubricating material, with the electrolyte powder, mass production capabilities can be ensured.

[0014] The above lubricating material can be formed on the outer surface of the anode active material powder through a chemical reaction of a plurality of precursors.

[0015] Specifically, the plurality of precursors includes a first precursor and a second precursor, and in the coating step, the surface of the positive electrode active material powder may be coated by chemically reacting the first precursor and the second precursor sequentially or simultaneously on the surface of the positive electrode active material powder. In the coating step, the first precursor in powder form and the second precursor in powder form may be mixed with the positive electrode active material powder.

[0016] For example, the first precursor may be a metal precursor, and the second precursor may be a chalcogen precursor.

[0017] The plurality of precursors may further include a third precursor different from the first precursor and the second precursor. In the coating step, the surface of the positive electrode active material powder may be coated by chemically reacting the first precursor, the second precursor, and the third precursor sequentially or simultaneously on the surface of the positive electrode active material powder.

[0018] For example, the third precursor may be a halogen compound. Halogen compounds may include HCl, NH₄Cl, SnCl₂, SnCl₄, ZnCl₂, HI, NH₄I, SnI₂, PbI₂, HBr, NH₄Br, etc. Accordingly, the lubricating material coated on the surface of the cathode active material powder may be changed or specified depending on the type of precursor supplied and / or the order of the precursors supplied.

[0019] The heat required for the chemical reaction can be secured through the heat (frictional heat) generated when the above-mentioned positive active material powder, the above-mentioned first precursor, and the above-mentioned second precursor are mixed. When a third precursor is further mixed, the heat required for the chemical reaction can be secured through the heat (frictional heat) generated when the above-mentioned positive active material powder, the above-mentioned first precursor, the above-mentioned second precursor, and the above-mentioned third precursor are mixed.

[0020] The metal precursor may be a compound comprising at least one of molybdenum (Mo) and tungsten (W). Additionally, the chalcogen precursor may be a compound comprising sulfur (S). As an example, the chalcogen precursor may be a sulfur precursor.

[0021] The above lubricating material may be formed from at least one of a metal chalcogenide compound, a metal halogen compound, molybdenum sulfide, tungsten sulfide, boron nitride, indium, Teflon, and graphite. Accordingly, the above voids can be reduced without hindering the movement of ions and electrons in the all-solid-state battery.

[0022] The coating step described above may be performed inside a reactor. For example, the interior of the reactor may be maintained under vacuum. The heat required for the chemical reaction in the coating step may also be obtained by heating the reactor.

[0023] In the above compression step, a portion of the electrolyte powder may be mixed with the anode active material powder and a compressed anode composite layer and an electrolyte layer formed by compressing the electrolyte powder on the anode composite layer may be formed. Accordingly, the voids within the anode composite layer may be reduced by the lubricating material.

[0024] The electrolyte powder can be crushed and attached to the surface of the positive electrode active material powder within the positive electrode composite layer. Accordingly, the mobility (degree of freedom of movement) of the electrolyte powder attached to the surface of the positive electrode active material powder can be improved by the lubricating material.

[0025] When the electrolyte powder is crushed and attached to the outer surface of the positive electrode active material powder, the electrolyte powder can be moved to fill the voids within the positive electrode composite by the lubricating material. Accordingly, the voids within the positive electrode composite can be reduced by the lubricating material.

[0026] A negative electrode active material may be disposed opposite the positive electrode active material with the electrolyte powder interposed therebetween, and a negative electrode current collector may be disposed on the negative electrode active material.

[0027] In the above compression step, the voids within the anode composite can be reduced as the electrolyte powder slides around the anode active material due to the lubricating material.

[0028] A method for manufacturing an all-solid-state battery according to another embodiment of the present invention may include: a mixture forming step of mixing a lubricating material, a positive electrode active material powder, and an electrolyte powder to form a mixture; a coating step of applying the mixture onto a positive electrode current collector; and a compression step of compressing the mixture and the positive electrode current collector together. According to the present embodiment, the mobility (degree of freedom of movement) of the electrolyte powder, which is compressed and attached to the circumference of the positive electrode active material powder, is improved, thereby reducing voids within the positive electrode composite, and as a result, the performance of the all-solid-state battery can be improved. Effects of the invention

[0029] According to the present invention, a method for manufacturing an all-solid-state battery can be provided that can reduce voids in an anode composite formed by pressing an anode active material powder and an electrolyte powder.

[0030] In addition, according to the present invention, a method for manufacturing an all-solid-state battery can be provided, which can reduce resistance within the all-solid-state battery and improve the performance of the all-solid-state battery by reducing voids within the anode composite.

[0031] In addition, according to the present invention, a method for manufacturing an all-solid-state battery can be provided that can improve the mass production capability of the all-solid-state battery. Brief explanation of the drawing

[0032] FIG. 1 is a conceptual diagram of an all-solid-state battery according to an embodiment of the present invention. Figure 2 is an example illustrating a method of compressing a positive electrode active material and an electrolyte. Figure 3 (a) is a conceptual diagram showing the voids in the anode composite formed when the anode active material powder and the electrolyte powder are compressed, and (b) is a conceptual diagram showing the voids in the anode composite formed when the anode active material powder and the electrolyte powder coated with a lubricating material are compressed. FIG. 4 is a flowchart of a method for manufacturing an all-solid-state battery according to one embodiment of the present invention. FIG. 5 is a flowchart of a method for manufacturing an all-solid-state battery according to another embodiment of the present invention. Specific details for implementing the invention

[0033] Hereinafter, a method for manufacturing an all-solid-state battery according to an embodiment of the present invention will be described in detail with reference to the attached drawings. The attached drawings illustrate exemplary forms of the present invention and are provided only to explain the present invention in more detail; the technical scope of the present invention is not limited thereby.

[0034] Additionally, identical or corresponding components are assigned the same reference number regardless of the drawing symbol, and redundant descriptions thereof are omitted; furthermore, for the convenience of explanation, the size and shape of each illustrated component may be exaggerated or reduced.

[0035] In addition, in describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such descriptions could obscure the essence of the invention.

[0037] FIG. 1 is a conceptual diagram of an all-solid-state battery according to an embodiment of the present invention.

[0038] Referring to FIG. 1, an all-solid-state battery according to an embodiment of the present invention may include a positive current collector (100), a positive active material (200) on the positive current collector (100), a negative active material (400) on the positive active material, an electrolyte (300) between the positive active material (200) and the negative active material (400), and a negative current collector (500) on the negative active material (400).

[0039] The above positive current collector (100) and the above negative current collector (500) serve to collect electrons generated by the electrochemical reaction of active materials (positive active material and negative active material) or to supply electrons required for the electrochemical reaction.

[0040] The above-mentioned positive active material (200) may be provided in the form of a solid powder and may be compressed with an electrolyte (e.g., a solid electrolyte) (300) described later. For example, both the positive active material (200) and the electrolyte (300) may be supplied in the form of a solid powder, and the electrolyte (300) powder may be mixed onto the positive active material (200) powder so that the positive active material (200) powder and the electrolyte (300) powder may be compressed together. Here, 'powder' may refer to a material formed by the aggregation of fine particles, or a state in which fine solid particles are dispersed and gathered.

[0041] The above positive active material (200) is Lithium-rich Layered Oxides (Li 1-X Ni X Mn X Co X O2), Iron Fluoride, Lithium Nickel Phosphate(LiNiPO4), Lithium Cobalt Phosphate(LiCoPO4), Lithium Vanadium Phosphate(Li3V2(PO4)3), Lithium Manganese Phosphate(LiMnPO4), Lithium Iron Phosphate(LiFePO4), Lithium Nickel Manganese Oxide(LiNi X Mn 2-X O4), Lithium Manganese Oxide(LiMn2O4), Lithium Nickel Cobalt Aluminum Oxide(NCA, LiNi X Co X Al Y O2), Lithium Nickel Manganese Cobalt Oxide (NMC, LiNi X Mn Y Co X It can be formed from at least one of O2), Lithium Cobalt Oxide (LiCoO2), or two or more of these compounds.

[0042] The above electrolyte (300) can be formed as a solid and can be supplied in the form of a powder. That is, the solid electrolyte (300) powder can be supplied onto the positive active material (200) powder, so that the positive active material (200) powder and the electrolyte (300) powder can be compressed against each other. Through this compression, at least a portion of the electrolyte (300) powder can be mixed into the space between the positive active material (200) powders, and the remainder of the electrolyte (300) powder can be deposited on the positive active material (200) powder.

[0043] The above electrolyte (300) is Lithium Phosphorus Sulfide (Li3PS4), Lithium Thiophosphate (Li7P3S 11 ), Argyrodite-type Li6PS5X(X=Cl, Br, I), Lithium Germanium Sulfide(Li 10 GeP2S 12 ), Lithium Tin Sulfide(Li 10 SnP2S 12 ), Lithium Antimony Sulfide(Li3SbS4), Lithium Boron Sulfide(Li2B6S 10 It can be formed from at least one of Lithium Phosphorus Oxynitride (LiPON), Lithium Super Ionic Conductor (LISICON), etc.

[0044] The above negative electrode active material (400) may be disposed facing the positive electrode active material (200) on the electrolyte (300). For example, the above negative electrode active material (400) may be provided in the form of a solid film.

[0045] The above negative electrode active material (400) can be formed from lithium, silicon, graphite, or an Ag / CNT composite, etc.

[0046] The positive current collector (100) may be laminated on the outer surface of the positive active material (200), and the negative current collector (500) may be laminated on the outer surface of the negative active material (400).

[0047] Meanwhile, a compression process can be performed while the positive active material (200) powder and the electrolyte (300) powder are supplied onto the positive current collector (100), and FIG. 2 shows an example of such compression.

[0048] Referring to FIG. 2, when the positive active material (200) powder and the electrolyte (300) powder are supplied onto the positive current collector (100), the positive active material (200) powder and the electrolyte (300) powder on the positive current collector (100) can be compressed through a pair of rollers (700). Although the layers of the positive active material (200) powder and the electrolyte (300) powder are separated in the drawing, it is also possible to supply a pre-mixed mixture of the positive active material (200) powder and the electrolyte (300) powder onto the positive current collector (100) and compress it through a pair of rollers (700).

[0049] Although not illustrated, the mixture of the positive active material (200) powder and the electrolyte (300) powder may further include at least one of a binder and a conductive material.

[0050] For example, the binder may be polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, diacetylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, a polymer containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc. As the binder, one or more of the examples described above may be used.

[0051] For example, conductive materials such as Ketjen Black, Carbon Black, SuperC, SuperP, Carbon Nano Tube (CNT), Vapor Grown Carbon Fiber (VGCF) can be used.

[0052] Since these binders and conductive materials are already known, a detailed explanation thereof is omitted.

[0053] FIG. 2 illustrates an example of pressing the positive active material (200) powder and the electrolyte (300) powder onto the positive current collector (100) using a pair of rollers (700), but in addition to pressing using rollers, it is also possible to use known pressing methods such as surface pressing or vacuum pressing.

[0054] As shown in FIG. 1, when the positive active material (200) powder and the electrolyte (300) powder are compressed against each other, a cathode composite layer in which the positive active material (200) powder and the electrolyte (300) powder are mixed can be formed. The cathode composite layer can be formed in a form in which the electrolyte (300) powder is crushed and attached to the outer surface of the positive active material (200) powder.

[0055] A number of voids (C), which will be described below, may be formed in this anode composite layer, and these voids (C) may act as internal resistance and become a factor that degrades the performance of the all-solid-state battery.

[0056] According to one embodiment of the present invention, the void (C) can be reduced by adding a lubricating material (250) before or when the positive active material (200) powder and the electrolyte (300) powder are pressed together.

[0057] The above lubricating material (250) may be formed on the outer surface of the anode active material powder through a chemical reaction of a plurality of precursors. The plurality of precursors may include a first precursor and a second precursor. The first precursor and the second precursor may be different from each other. Additionally, the lubricating material (250) may further include a third precursor that is identical to or different from the first precursor and the second precursor.

[0058] The above lubricating material (250) may be formed from at least one of a metal chalcogen compound, a metal halogen compound, molybdenum sulfide, tungsten sulfide, boron nitride, indium, Teflon, and graphite. For example, the lubricating material may be formed through a chemical reaction between the first precursor and the second precursor, or through a chemical reaction between the first precursor and the third precursor.

[0059] As illustrated in FIG. 1, according to one embodiment, before the positive active material (200) powder and the electrolyte (300) powder are pressed together, the solid lubricating material (250) may be pre-coated onto the positive active material (200) powder.

[0060] Additionally, although not illustrated, according to another embodiment, when the positive active material (200) powder and the electrolyte (300) powder are compressed, the solid lubricating material (250) may be supplied in addition to the positive active material (200) powder and the electrolyte (300) powder.

[0061] When the positive electrode active material (200) powder and the electrolyte (300) powder are compressed, the mobility (or degree of freedom of movement) of the electrolyte (300) powder can be increased by the lubricating material (250). That is, even if the electrolyte (300) powder is crushed and attached to the outer surface of the positive electrode active material (200) powder, the electrolyte (300) powder can move to fill the void (C) by the lubricating material (250).

[0062] FIG. 3 is a conceptual diagram showing the difference in the gap (C) when there is no lubricating material (250) and when a lubricating material (250) is added during the compression of the positive active material (200) powder and the electrolyte (300) powder.

[0063] Specifically, (a) of FIG. 3 shows a void within the anode composite formed when the anode active material powder and the electrolyte powder are compressed, and (b) is a conceptual diagram showing a void within the anode composite formed when the anode active material powder and the electrolyte powder coated with a lubricating material are compressed.

[0064] Referring to FIG. 3(a), when the positive active material (200) powder and the electrolyte (300) powder are compressed in the absence of a lubricating material (250), it can be seen that a relatively large number of (relatively large volume) voids (C) are formed in the positive composite (see FIG. 1) after compression.

[0065] In contrast, referring to FIG. 3(b), when a lubricating material (250) is provided (for example, when the lubricating material (250) is coated on the anode active material (200) powder), it can be seen that the number of voids (C) (or the volume of voids (C)) is relatively reduced.

[0066] In this way, when a lubricating material (250) is provided during the compression of the positive active material (200) powder and the electrolyte (300) powder (for example, when the lubricating material (250) is coated on the positive active material (200) powder), the performance of the all-solid-state battery can be improved due to the reduction of voids (C) within the positive composite.

[0067] Hereinafter, a method for manufacturing an all-solid-state battery according to an embodiment of the present invention will be described with reference to other drawings. Meanwhile, in describing the method for manufacturing an all-solid-state battery, it is obvious that the configuration of the all-solid-state battery described above can be applied in the same way to the method for manufacturing an all-solid-state battery.

[0069] FIG. 4 is a flowchart of a method for manufacturing an all-solid-state battery according to one embodiment of the present invention.

[0070] Referring to FIG. 4, a method for manufacturing an all-solid-state battery according to one embodiment of the present invention may include a mixture forming step (S20), a coating step (S30), and a compression step (S40).

[0071] In the above mixture formation step (S20), a mixture may be formed by mixing a positive electrode active material (200) powder coated with a lubricating material (250) and an electrolyte (300) powder. That is, the mixture is a mixture of a positive electrode active material (200) powder coated with a lubricating material (250) and an electrolyte (300) powder, and the mixture may further include at least one of a binder and a conductive material that have already been disclosed.

[0072] In the above mixture forming step (S20), the electrolyte (300) powder is mixed with the positive electrode active material (200) powder, and at the same time, the electrolyte (300) powder may be further disposed on the positive electrode active material (200) powder. That is, in the above mixture forming step (S20), a portion of the electrolyte (300) powder is mixed with the positive electrode active material (200) powder, and the remainder of the electrolyte (300) powder may be disposed on the positive electrode active material (200).

[0073] In the above coating step (S30), the mixture may be applied onto a film-shaped positive current collector (100). That is, the mixture may be provided onto the positive current collector (100) for the compression described later.

[0074] In the above compression step (S40), the mixture and the positive current collector (100) can be compressed together. That is, in the above compression step (S40), the positive active material (200) powder and the electrolyte (300) powder can be compressed together on the positive current collector (100).

[0075] A portion of the above electrolyte (300) powder may be inserted between the positive active material (200) powders to form a positive composite layer, and the remainder of the above electrolyte (300) powder may be compressed to form an electrolyte layer on the positive composite layer.

[0076] At this time, in the anode composite layer, the electrolyte (300) powder can be attached to the outer surface of the anode active material (200) while being crushed, and the mobility (or degree of freedom of movement) of the electrolyte (300) powder can be improved by the lubricating material (250).

[0077] That is, in the above compression step (S40), the electrolyte (300) powder slides around the circumference of the anode active material (200) powder by means of the lubricating material (250), thereby reducing the voids within the anode composite.

[0078] Accordingly, the performance of the all-solid-state battery can be improved by reducing the voids (C) in the anode composite formed by the compression of the anode active material (200) powder and the electrolyte (300) powder.

[0079] According to one embodiment of the present invention, a coating step (S10) may be further included before the mixture forming step (S20).

[0080] In the above coating step (S10), the solid lubricating material (250) may be coated onto the positive active material (200) powder. When the electrolyte (300) powder is crushed and attached to the outer surface of the positive active material (200) powder, the electrolyte (300) powder may move to fill the voids within the positive composite by means of the lubricating material (250).

[0081] The above lubricating material (250) may include a first precursor and a second precursor. The first precursor and the second precursor may be the same or different from each other. In this embodiment, the first precursor and the second precursor are different from each other. Additionally, the lubricating material (250) may further include a third precursor that is the same or different from the first precursor and the second precursor.

[0082] The above lubricating material (250) may be formed from at least one of a metal chalcogen compound, a metal halogen compound, molybdenum sulfide, tungsten sulfide, boron nitride, indium, Teflon, and graphite. That is, through at least two chemical reactions among the first precursor, the second precursor, and the third precursor, the lubricating material (250) may be formed from at least one of a metal chalcogen compound, a metal halogen compound, molybdenum sulfide, tungsten sulfide, boron nitride, indium, Teflon, and graphite.

[0083] For example, the first precursor of the lubricating material may be formed as a metal precursor, and the second precursor may be formed as a chalcogen precursor. That is, in the coating step, the surface of the positive electrode active material powder may be coated by chemically reacting the first precursor (e.g., a metal precursor) and the second precursor (e.g., a sulfur precursor) sequentially or simultaneously on the surface of the positive electrode active material powder. For example, the first precursor powder and the second precursor powder may be mixed with the positive electrode active material powder and chemically reacted on the surface of the positive electrode active material powder.

[0084] In addition, the plurality of precursors may further include a third precursor in addition to the first precursor and the second precursor, and the third precursor may be different from the first precursor and the second precursor. For example, the third precursor may be a halogen compound. Halogen compounds may include HCl, NH₄Cl, SnCl₂, SnCl₄, ZnCl₂, HI, NH₄I, SnI₂, PbI₂, HBr, NH₄Br, etc.

[0085] In this case, the first precursor powder, the second precursor powder, and the third precursor can be mixed with the positive active material powder and chemically reacted on the surface of the positive active material powder.

[0086] In this case, during the coating step, the surface of the positive electrode active material powder can be coated by chemically reacting the first precursor, the second precursor, and the third precursor sequentially or simultaneously on the surface of the positive electrode active material powder.

[0087] Here, sequentially chemically reacting the first precursor, the second precursor, and the third precursor may include supplying the first precursor, the second precursor, and the third precursor multiple times in different orders. For example, here, sequentially chemically reacting the first precursor, the second precursor, and the third precursor may include supplying the first precursor, supplying the second precursor, and supplying the third precursor sequentially, or supplying the first precursor, supplying the second precursor, supplying the first precursor, and supplying the third precursor sequentially.

[0088] The types of such multiple precursors, the supply order of the multiple precursors, and the number of times the multiple precursors are supplied can be appropriately selected based on the physical properties (physical characteristics and chemical specifics) of the lubricating material coated on the surface of the cathode active material powder.

[0089] For example, if the lubricating material contains the first precursor and the second precursor, the first precursor in powder form and the second precursor in powder form may be mixed with the anode active material powder during the coating step. For example, if the first precursor is a metal precursor and the second precursor, which is a chalcogen precursor, is a sulfur precursor, a chemical reaction between the metal precursor and the sulfur precursor may occur through Chemical Formula 1 below.

[0090] - Chemical Formula 1: MoClx + 2H2S -> MoS2 + 2HCl

[0091] The metal precursor may be a metal halogen compound precursor. For example, the metal precursor may be a compound containing at least one of molybdenum (Mo), tungsten (W), zirconium, titanium, nickel, cobalt, and iron. Additionally, the chalcogen precursor may be a compound containing sulfur (S), and may include, for example, inorganic or organic sulfur compounds such as elemental sulfur (S), hydrogen sulfide (H₂S), ammonium sulfide ((NH₄)₂S), thiourea, thioacetamide, and dimethyl disulfide (DMDS).

[0092] The coating step described above may be performed within a reactor (not shown). The heat required for the chemical reaction in the coating step may be obtained by heating the reactor. Alternatively, the heat required for the chemical reaction may be obtained through the heat generated when the cathode active material powder, the metal precursor, and the chalcogen precursor are mixed (e.g., frictional heat). Of course, it is also possible to obtain the heat required for the chemical reaction through both heating the reactor and frictional heat.

[0093] A negative electrode active material (400) may be disposed opposite the positive electrode active material (200) by interposing the electrolyte (300) powder. The negative electrode active material (400) may be formed in the form of a film. Additionally, a negative electrode current collector (500) may be disposed on the negative electrode active material (400).

[0094] Accordingly, according to the present embodiment, the performance of the all-solid-state battery can be improved by reducing the voids (C) within the anode composite formed by the compression of the anode active material (200) powder and the electrolyte (300) powder. In addition, the mass producibility of the all-solid-state battery can be improved.

[0095] Meanwhile, according to another embodiment of the present invention, the lubricating material (250) may not be pre-coated onto the positive active material (200) powder. For example, when mixing the positive active material (200) powder and the electrolyte (300) powder before the compression step, the lubricating material (250) may be mixed together. Hereinafter, a method for manufacturing an all-solid-state battery according to another embodiment of the present invention will be described with reference to other drawings.

[0097] FIG. 5 is a flowchart of a method for manufacturing an all-solid-state battery according to another embodiment of the present invention. This embodiment differs from the embodiment shown in FIG. 4 in that the lubricating material (250) is not pre-coated onto the positive electrode active material (200) powder, and the lubricating material (250) is mixed together with the positive electrode active material (200) powder and the electrolyte (300) powder when they are mixed. The differences from the embodiment of FIG. 4 will be explained below.

[0098] Referring to FIG. 5, the method for manufacturing an all-solid-state battery according to the present embodiment may include a mixture forming step (S100), a coating step (S200), and a pressing step (S300).

[0099] In the above mixture forming step (S100), the positive electrode active material (200) powder, the electrolyte (300) powder, and the solid lubricant (250) (or lubricant powder) are mixed, and at the same time, the electrolyte (300) powder may be further disposed on the positive electrode active material (200) powder. That is, in the above mixture forming step (S100), a portion of the electrolyte (300) powder is mixed with the positive electrode active material (200) powder and the lubricant (250), and the remainder of the electrolyte (300) powder may be disposed on the positive electrode active material (200).

[0100] In the above coating step (S200), the mixture may be applied onto a film-shaped positive current collector (100). That is, the mixture may be provided onto the positive current collector (100) for the compression described later.

[0101] In the above compression step (S300), the mixture and the positive current collector (100) may be compressed together. That is, in the above compression step (S300), the positive active material (200) powder, the electrolyte (300), and the lubricating material (250) (or lubricating material powder) may be compressed together on the positive current collector (100).

[0102] A portion of the above electrolyte (300) powder may be inserted between the anode active material (200) powders together with the above lubricating material (250) to form an anode composite layer, and the remainder of the above electrolyte (300) powder may be compressed onto the anode composite layer to form an electrolyte layer.

[0103] At this time, in the anode composite layer, the electrolyte (300) powder can be attached to the outer surface of the anode active material (200) while being crushed, and the mobility (or degree of freedom of movement) of the electrolyte (300) powder can be improved by the lubricating material (250).

[0104] That is, in the above compression step (S300), the electrolyte (300) powder slides around the circumference of the anode active material (200) powder by means of the lubricating material (250), thereby reducing the voids within the anode composite.

[0105] Accordingly, according to the present embodiment, the performance of the all-solid-state battery can be improved by reducing the voids (C) within the anode composite formed by the compression of the anode active material (200) powder and the electrolyte (300) powder. In addition, the mass producibility of the all-solid-state battery can be improved.

[0107] The preferred embodiments of the present invention described above are disclosed for illustrative purposes only, and those skilled in the art with ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims. Explanation of the symbols

[0108] 100 positive current collector 200 cathode active material 250 lubricating material 300 electrolytes 400 cathode active material 500 cathode current collector 700 rollers

Claims

Claim 1 A method for manufacturing an all-solid-state battery comprising: a coating step in which a lubricating material is coated onto a positive active material powder; a mixture forming step in which a mixture is formed by mixing the positive active material powder coated with the lubricating material and an electrolyte powder; a coating step in which the mixture is applied onto a positive current collector; and a compression step in which the mixture and the positive current collector are compressed against each other, wherein the lubricating material is formed on the outer surface of the positive active material powder through a chemical reaction of a plurality of precursors. Claim 2 delete Claim 3 A method for manufacturing an all-solid-state battery according to claim 1, wherein the plurality of precursors includes a first precursor and a second precursor, and in the coating step, the surface of the positive active material powder is coated by chemically reacting the first precursor and the second precursor sequentially or simultaneously on the surface of the positive active material powder. Claim 4 A method for manufacturing an all-solid-state battery according to claim 3, wherein the first precursor is a metal precursor and the second precursor is a chalcogen precursor. Claim 5 A method for manufacturing an all-solid-state battery according to claim 3, wherein the plurality of precursors further comprises a third precursor different from the first precursor and the second precursor, and in the coating step, the surface of the positive active material powder is coated by chemically reacting the first precursor, the second precursor, and the third precursor sequentially or simultaneously on the surface of the positive active material powder. Claim 6 A method for manufacturing an all-solid-state battery in which the heat required for the chemical reaction is secured through the heat generated when the positive active material powder, the first precursor, and the second precursor are mixed in paragraph 3. Claim 7 A method for manufacturing an all-solid-state battery according to claim 1, wherein the lubricating material is formed by at least one of a metal chalcogenide compound, a metal halogen compound, molybdenum sulfide, tungsten sulfide, boron nitride, indium, Teflon, and graphite. Claim 8 A method for manufacturing an all-solid-state battery according to claim 1, wherein in the compression step, a portion of the electrolyte powder is mixed with the positive active material powder and a positive composite layer formed by compression, and an electrolyte layer formed by compression of the electrolyte powder on the positive composite layer are formed. Claim 9 A method for manufacturing an all-solid-state battery according to claim 8, wherein the electrolyte powder is crushed and attached to the surface of the positive electrode active material powder within the positive electrode composite layer. Claim 10 A method for manufacturing an all-solid-state battery according to claim 9, characterized in that when the electrolyte powder is crushed and attached to the outer surface of the positive electrode active material powder, the electrolyte powder is moved by the lubricating material to fill the voids within the positive electrode composite. Claim 11 A method for manufacturing an all-solid-state battery according to claim 1, characterized in that, in the compression step, the electrolyte powder slides around the circumference of the positive electrode active material powder by means of the lubricating material, thereby reducing the voids within the positive electrode composite. Claim 12 A method for manufacturing an all-solid-state battery according to claim 1, wherein a negative electrode active material is disposed opposite the positive electrode active material with the electrolyte powder interposed therebetween, and a negative electrode current collector is disposed on the negative electrode active material.

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