Method for manufacturing positive electrode for all-solid-state battery, positive electrode for all-solid-state battery, and all-solid-state battery

Abstract

The present invention relates to a method for manufacturing a positive electrode for a full solid-state battery, a positive electrode for a full solid-state battery, and a full solid-state battery including the same. The method for manufacturing a positive electrode for a full solid-state battery includes the steps of forming a unit active material layer by a dry process, the unit active material layer including a first layer and a second layer, the first layer including a first positive electrode active material and a first solid electrolyte, the second layer including a second positive electrode active material and a second solid electrolyte; forming a stack in which the first layer and the second layer are alternately arranged in a first direction; slicing the stack in a second direction crossing the first direction to form a positive electrode active material layer; and laminating the positive electrode active material layer on a positive electrode current collector such that the first layer and the second layer are in contact with the positive electrode current collector.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2024-0175409, filed on November 29, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a method for manufacturing a positive electrode for an all-solid-state battery, a positive electrode for an all-solid-state battery manufactured using the method, and an all-solid-state battery including the positive electrode. Background Technology

[0003] Due to increasing demand, there is active development of batteries with high energy density and safety. For example, lithium-ion batteries are used not only in information and communication devices but also in fields such as automobiles. In the automotive sector, safety is paramount because it is directly related to protecting human life.

[0004] All-solid-state batteries, in which a solid electrolyte is used instead of a liquid electrolyte, have been proposed. Because all-solid-state batteries do not use flammable organic dispersion media, they significantly reduce the likelihood of fire or explosion, even in the event of a short circuit. Therefore, such all-solid-state batteries offer significantly higher safety than lithium-ion batteries that use liquid electrolytes. Summary of the Invention

[0005] This disclosure describes a method for manufacturing a positive electrode for an all-solid-state battery that has both improved electronic and ionic conductivity.

[0006] This disclosure also describes a positive electrode for all-solid-state batteries that has both improved electronic and ionic conductivity.

[0007] This disclosure also describes an all-solid-state battery with high capacity and high output characteristics.

[0008] In an exemplary embodiment of this disclosure, a method for manufacturing a positive electrode for an all-solid-state battery may include the following steps: forming a unit active material layer by a dry process, the unit active material layer including a first layer and a second layer, the first layer including a first positive electrode active material and a first solid electrolyte, the second layer including a second positive electrode active material and a second solid electrolyte, the second layer being on the first layer; forming a stack in which the first layer and the second layer are alternately arranged in a first direction; slicing the stack in a second direction intersecting the first direction to form a positive electrode active material layer, the step of slicing the stack including cutting the first layer and the second layer together; and laminating the positive electrode active material layer onto a positive electrode current collector such that the first layer and the second layer can contact the positive electrode current collector.

[0009] In an exemplary embodiment of this disclosure, the positive electrode for an all-solid-state battery may include a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector. The positive electrode active material layer may include: a first layer comprising a first positive electrode active material and a first solid electrolyte; and a second layer comprising a second positive electrode active material and a second solid electrolyte. The second layer is in contact with the first layer, and the first and second layers may be disposed side-by-side on the positive electrode current collector.

[0010] In exemplary embodiments of this disclosure, an all-solid-state battery may include a positive electrode layer, a negative electrode layer, and a solid electrolyte layer between the positive electrode layer and the negative electrode layer. The positive electrode layer may include a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector. The positive electrode active material layer may include: a first layer comprising a first positive electrode active material and a first solid electrolyte; and a second layer comprising a second positive electrode active material and a second solid electrolyte. The second layer is in contact with the first layer, and the first and second layers may be disposed side-by-side on the positive electrode current collector. Attached Figure Description

[0011] Figure 1 This is a cross-sectional view of an all-solid-state battery according to an exemplary embodiment of the present disclosure.

[0012] Figure 2 yes Figure 1 A magnified view of the area designated as "M".

[0013] Figure 3 This is a cross-sectional view of an all-solid-state battery according to another exemplary embodiment of the present disclosure.

[0014] Figure 4 This is a cross-sectional view of an all-solid-state battery according to another exemplary embodiment of the present disclosure.

[0015] Figure 5 This is a cross-sectional view of an all-solid-state battery according to another exemplary embodiment of the present disclosure.

[0016] Figure 6 This is a cross-sectional view of an all-solid-state battery according to a comparative example of this disclosure.

[0017] Figure 7 yes Figure 6 A magnified view of the region designated as "N".

[0018] Figures 8 to 11 This is a perspective view illustrating a method for manufacturing a positive electrode for an all-solid-state battery according to an exemplary embodiment of the present disclosure.

[0019] Figure 12 and Figure 13 This is a perspective view illustrating a method for manufacturing a positive electrode for an all-solid-state battery according to another exemplary embodiment of the present disclosure.

[0020] Figure 14 and Figure 15 This is a perspective view illustrating a method for manufacturing a positive electrode for an all-solid-state battery according to another exemplary embodiment of the present disclosure.

[0021] Figure 16 This is a flowchart illustrating a method for manufacturing a positive electrode for an all-solid-state battery according to various example embodiments. Detailed Implementation

[0022] To fully understand the structure and effects of this disclosure, exemplary embodiments of the disclosure are described with reference to the accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed below and can be implemented and modified in various forms. Rather, these exemplary embodiments are provided so that this disclosure is thorough and complete, and fully conveys the scope of this disclosure to those skilled in the art.

[0023] In this specification, it is understood that when an element is referred to as being "on" another element, the element may be "directly on" the other element, or an intervening element may be present therein. In the accompanying drawings, the thickness of the components may be exaggerated for the purpose of effectively explaining the technical content. Throughout the specification, the same reference numerals or symbols refer to the same elements.

[0024] The exemplary embodiments described herein are explained with reference to cross-sectional views and / or plan views, which serve as ideal illustrations of this disclosure. In the drawings, the thickness of the films and regions may be exaggerated for the purpose of effectively explaining the technical content. Therefore, the regions shown in the drawings are schematic, and the shapes of the regions shown in the drawings are intended to illustrate the specific shapes of the regions of the elements and are not intended to limit the scope of the disclosure. In the various exemplary embodiments of this specification, terms such as first, second, and third are used to describe various components, but these components should not be limited by these terms. These terms are used only to distinguish one component from another. The exemplary embodiments described and illustrated herein also include supplementary embodiments thereof.

[0025] The terminology used herein is for describing exemplary embodiments and is not intended to limit this disclosure. In this specification, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "comprising / including" and / or variations thereof as used herein do not exclude the presence or addition of one or more other components.

[0026] In this specification, "combination thereof" may refer to mixtures, stacks, complexes, copolymers, alloys, blends, and reaction products of the components.

[0027] Unless otherwise defined herein, particle size can refer to average particle size. Furthermore, particle size can refer to average particle size (D50), which means the diameter of particles that constitute approximately 50% of the total volume in a particle size distribution. Average particle size (D50) can be measured by methods known to those skilled in the art, for example, by a particle size analyzer, or also using transmission electron microscopy (TEM) images or scanning electron microscopy (SEM) images. Optionally, average particle size can be measured using a measuring device employing dynamic light scattering, wherein the number of particles is counted for each particle size range by performing data analysis, and the average particle size (D50) value can then be obtained by calculation. Additionally, average particle size can be measured using laser diffraction. When measured by laser diffraction, for example, after dispersing the particles to be measured in a dispersion medium, the dispersion medium is introduced into a commercially available laser diffraction particle size analyzer (e.g., Microtrac MT 3000) and irradiated with ultrasound at an output of about 60W at about 28kHz, the average particle size (D50) based on about 50% of the particle size distribution in the analyzer can then be calculated.

[0028] In this specification, each of the phrases such as “A or B”, “at least one of A and B (species / man)”, “at least one of A or B (species / man)”, “A, B or C”, “at least one of A, B and C (species / man)” and “at least one of A, B or C (species / man)” may include any one of the items listed with the corresponding phrase or any possible combination thereof.

[0029] In this specification, "dry" or "dry process" can refer to a state in which the adhesive may come into unintentional contact with a solvent (such as a process solvent) or a state in which the adhesive may contain a solvent unintentionally. For example, a dry adhesive can refer to an adhesive in which the adhesive may come into unintentional contact with a solvent or an adhesive that may contain a solvent unintentionally. For example, an adhesive that is in a liquid state at room temperature and does not mix with a solvent can be a dry adhesive.

[0030] In this specification, "dry electrode" or "dry electrode film" can refer to an electrode or electrode film that may not contain solvent or may not intentionally use solvent during electrode preparation. Solvents may include process solvents, process solvent residues, process solvent impurities, etc.

[0031] In this specification, a "self-standing membrane" may include an adhesive matrix structure, and the electrode membrane or electrode layer may be self-standing or self-supporting by being supported by the adhesive matrix structure. Self-standing electrode membranes or self-standing electrode active material layers, by including an adhesive matrix structure, are used to manufacture rechargeable lithium-ion batteries without supports (such as current collectors). For example, a self-standing electrode membrane or self-standing electrode active material layer may have sufficient membrane or layer strength to be rolled, handled, and / or unfolded without other supports.

[0032] When the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, it is intended that the relevant numerical value include a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​within that range, such as increments of 0.1%.

[0033] Figure 1 This is a cross-sectional view of an all-solid-state battery according to an exemplary embodiment of the present disclosure.

[0034] Reference Figure 1 The cell cell (CEL) of the all-solid-state battery according to this disclosure may include a positive electrode layer 100, a negative electrode layer 200 opposite to the positive electrode layer 100, and a solid electrolyte layer 300 disposed between the positive electrode layer 100 and the negative electrode layer 200. However, this disclosure is not limited to this, and the cell cell (CEL) may also include at least one additional functional layer (e.g., an adhesion improvement layer) disposed between the positive electrode layer 100 and the solid electrolyte layer 300 or between the negative electrode layer 200 and the solid electrolyte layer 300.

[0035] According to an exemplary embodiment of this disclosure, the positive electrode layer 100 may include a positive electrode current collector 110 and a positive electrode active material layer 120 disposed on the positive electrode current collector 110. The positive electrode active material layer 120 may include at least one of a positive electrode active material, a solid electrolyte, a conductive material, and a binder.

[0036] The positive electrode current collector 110 can provide a reference surface on which a positive electrode active material layer 120 may be disposed. The positive electrode current collector 110 may include, for example, a plate or foil containing at least one of indium (In), copper (Cu), magnesium (Mg), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), and alloys thereof.

[0037] On the other hand, with Figure 1The construction shown is different, and in one example embodiment of this disclosure, the positive electrode current collector 110 may be omitted. Although not shown, a carbon layer having a thickness in the range of about 0.1 μm to about 4 μm may be further disposed between the positive electrode current collector 110 and the positive electrode active material layer 120 in order to increase the adhesion between the positive electrode current collector 110 and the positive electrode active material layer 120.

[0038] The positive electrode active material of the positive electrode active material layer 120 may include a material capable of reversibly inserting and deintercalating lithium ions. The positive electrode active material may include multiple particles. The positive electrode active material may include, for example, lithium transition metal oxides (such as or including at least one of lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganese oxide, and lithium iron phosphate), nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide, but is not necessarily limited thereto. The positive electrode active material may be used alone or may be a mixture of two or more thereof.

[0039] Lithium transition metal oxides may be or include, for example, those made of Li a A 1-b B b D2 (0.90≤a≤1, 0≤b≤0.5), Li a E 1-b B b O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (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 O 2-α F α (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 (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Ni1-b-c Mn b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni b E c G d O2 (0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Ni b Co c Mn d GeO2 (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 (0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2 (0.90≤a≤1, 0.001≤b≤0.1), Li a MnG b O2 (0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2GbO4 (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 Compounds represented by either Fe2(PO4)3 (0≤f≤2) or LiFePO4. In these compounds, the capital letter "A" is or includes at least one of Ni, Co, Mn and combinations thereof; the capital letter "B" is or includes at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements and combinations thereof; the capital letter "D" is or includes at least one of O, F, S, P and combinations thereof; the capital letter "E" is or includes at least one of Co, Mn and combinations thereof; the capital letter "F" is or includes at least one of F, S, P and combinations thereof; the capital letter "G" is or includes at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and combinations thereof; the capital letter "Q" is or includes at least one of Ti, Mo, Mn and combinations thereof; the capital letter "I" is or includes at least one of Cr, V, Fe, Sc, Y and combinations thereof; and the capital letter "J" is or includes at least one of V, Cr, Mn, Co, Ni, Cu and combinations thereof.

[0040] The positive electrode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock salt-type structure among the above-described lithium transition metal oxides. The "layered rock salt-type structure" is, for example, a structure in which oxygen atom layers and metal atom layers are alternately and regularly arranged in the <111> direction of the cubic rock salt-type structure, whereby each atomic layer forms a two-dimensional plane. The "cubic rock salt-type structure" refers to a sodium chloride-type (NaCl-type) structure as a type of crystal structure. For example, it refers to a structure in which face-centered cubic lattices (fcc) formed by each of cations and anions are offset by half (1 / 2) of the edge of the unit lattice. The lithium transition metal oxide having such a layered rock salt structure may be or include, for example, a ternary lithium transition metal oxide (such as LiNi x Co y Al z O2 (NCA) or LiNi x Co y Mn z O2 (NCM) (0 < x < 1, 0 < y < 1, 0 < z < 1, x + y + z = 1)). When the positive electrode active material includes a ternary lithium transition metal oxide having a layered rock salt-type structure, the energy density of the unit cell CEL can be increased and the thermal stability can be improved.

[0041] The above-described compound included in the positive electrode active material may be covered with a coating layer (not shown). The positive electrode active material may also be a mixture of the above-described compound and a compound to which the coating layer is added. For example, the coating layer added to the surface of the positive electrode active material may include at least one of oxides, hydroxides, oxyhydroxides, carbonate oxy salts, and bicarbonate salts of the following coating elements. The compound constituting or included in the coating layer may be amorphous or crystalline. The coating elements included in the coating layer may include at least one of Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, and mixtures thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO), etc. The method for forming the coating layer is determined within a range that does not adversely affect the physical properties of the positive electrode active material. The method for forming the coating layer may include, for example, a spraying method or an impregnation method.

[0042] When the positive electrode active material is a ternary lithium transition metal oxide such as NCA or NCM and contains nickel (Ni), the capacity density of the cell electrode (CEL) can be increased, thereby reducing metal leaching of the positive electrode active material during charging. As a result, the cycle characteristics of the cell electrode during charging can be improved. For example, "cycle characteristics" is a property that indicates the degree of degradation of the cell electrode due to charging / discharging. A cell electrode with high cycle characteristics may exhibit only a small degree of degradation due to charging / discharging, while a cell electrode with low cycle characteristics may exhibit a large degree of degradation due to charging / discharging.

[0043] Positive electrode active materials can have particle shapes such as spherical or ellipsoidal. There are no particular restrictions on the particle size and content of positive electrode active materials.

[0044] The solid electrolyte of the positive electrode active material layer 120 may have a particulate shape. The solid electrolyte may be dispersed between the positive electrode active materials. The solid electrolyte may include sulfide-based solid electrolytes with desired or improved lithium-ion conductivity properties. Sulfide-based solid electrolytes may include, for example, Li₂S-P₂S₅, Li₂S-P₂S₅-LiX (where X represents a halogen element), 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 (m and n are positive numbers, and the uppercase letter "Z" represents any one of Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p and q are positive numbers, and the uppercase letter "M" represents any one of P, Si, Ge, B, Al, Ga, and In), 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 At least one of (0≤x≤2).

[0045] Sulfide solid electrolytes may be or include, for example, Li 7-xPS 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 A sulfide-germanium ore type compound comprising at least one of (0≤x≤2). For example, a sulfide solid electrolyte may be or include a sulfide-germanium ore type compound comprising at least one of Li6PS5Cl, Li6PS5Br and Li6PS5I.

[0046] Optionally, the sulfide-based solid electrolyte may be or may include Li 7-a M a PS 6-c X c A sulfide-germanium ore-type compound (0≤a≤2, 0≤c≤2). Here, X can be or include at least one of F, Br, Cl, I, and combinations thereof. M can be or include at least one of scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), and combinations thereof.

[0047] The density of the argyrogermanium sulfide solid electrolyte can range from about 1.5 g / cc to about 2.0 g / cc. Because the argyrogermanium sulfide solid electrolyte has a density of about 1.5 g / cc or greater, the internal resistance of the all-solid-state battery can be reduced, and defects such as the solid electrolyte film being penetrated and short-circuited due to the formation of lithium dendrites can be reduced or prevented. The elastic modulus of the solid electrolyte can, for example, range from about 15 GPa to about 35 GPa.

[0048] The solid electrolyte included in the positive electrode active material layer 120 can have a smaller average particle size than the solid electrolyte included in the solid electrolyte layer 300 described below. For example, the average particle size of the solid electrolyte in the positive electrode active material layer 120 can be in the range of about 90% or less, about 80% or less, about 70% or less, about 60% or less, about 50% or less, about 40% or less, about 30% or less, or about 20% or less of the average particle size of the solid electrolyte in the solid electrolyte layer 300. The average particle size can be the median diameter measured using, for example, a laser-type particle size distribution analyzer.

[0049] The positive electrode active material layer 120 may include a conductive material. The conductive material can exhibit conductivity without causing chemical changes in the cell cell (CEL), thereby increasing the conductivity of both the positive electrode active material and the solid electrolyte. The conductive material may include carbon-based materials. The conductive material may include at least one of, for example, graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0050] The positive electrode active material layer 120 may further include an adhesive. The adhesive may be configured to bond the positive electrode active material, solid electrolyte, conductive material, etc., in the positive electrode active material layer 120 to each other. The adhesive may include materials that improve the bonding force between the positive electrode active material layer 120 and the positive electrode current collector 110. The adhesive may include at least one of, for example, polyvinylidene fluoride, styrene-butadiene rubber (SBR), polytetrafluoroethylene, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, and polymethyl methacrylate.

[0051] A solid electrolyte layer 300 may be disposed between the positive electrode layer 100 and the negative electrode layer 200. The solid electrolyte layer 300 may include a sulfide-based solid electrolyte having desired or improved lithium-ion conductivity characteristics. The solid electrolyte in the solid electrolyte layer 300 may be the same as or different from any of the materials included in the solid electrolyte in the aforementioned positive electrode active material layer 120.

[0052] Solid electrolytes can have a particulate shape (e.g., spherical or ellipsoidal). Solid electrolytes can include sulfide-based solid electrolytes. Sulfide-based solid electrolytes can be formed by processing starting materials such as Li₂S and P₂S₅, for example, through melt quenching, mechanical grinding, etc. Furthermore, heat treatment can be performed after processing. Solid electrolytes can be amorphous, crystalline, or a mixture of amorphous and crystalline states. Additionally, solid electrolytes can include at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements, for example, those found in the aforementioned sulfide-based solid electrolyte materials. For example, a solid electrolyte can be a material comprising Li₂S-P₂S₅. When a sulfide-based solid electrolyte material comprising Li₂S-P₂S₅ is used to form a solid electrolyte, the molar ratio of Li₂S to P₂S₅ is, for example, in the range of Li₂S:P₂S₅ = 50:50 to 90:10.

[0053] In an example embodiment, the solid electrolyte may include Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2) and Li 7-x PS 6-x I x The solid electrolyte may include at least one of the following silver-germanium sulfide compounds: Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0054] In another example embodiment, the solid electrolyte may include Li 7-a M a PS 6-c X cA sulfide-silver-germanium ore-type compound. Here, X can be or include at least one of F, Cl, Br, and combinations thereof. M can be or include at least one of scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), and combinations thereof. M can be or include at least one of Na, K, Fe, Mg, Ca, Ag, Cu, Zr, Zn, and combinations thereof. Each of “a” and “c” can be a real number in the range between 0 and 2.

[0055] The density of argyrocerium sulfide solid electrolytes can range from about 1.5 g / cc to about 2.0 g / cc. Because argyrocerium sulfide solid electrolytes have a density of about 1.5 g / cc or greater, the internal resistance of all-solid-state batteries can be reduced, and defects such as the solid electrolyte film being penetrated and short-circuited due to the formation of lithium dendrites can be reduced or prevented. The elastic modulus of the solid electrolyte can, for example, range from about 15 GPa to about 35 GPa.

[0056] The solid electrolyte layer 300 may also include an adhesive. The adhesive included in the solid electrolyte layer 300 may include, for example, at least one of styrene-butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited thereto. The adhesive of the solid electrolyte layer 300 may be the same as or different from the adhesive included in the positive electrode active material layer 120 or the adhesive included in the coating layer 220.

[0057] The negative electrode layer 200 may include a negative electrode current collector 210 and a coating layer 220 on the negative electrode current collector 210.

[0058] The negative electrode current collector 210 can provide a reference surface on which a coating layer 220 may be disposed. The negative electrode current collector 210 may comprise, for example, a material that does not react with lithium (i.e., does not form an alloy or compound with lithium). For example, the negative electrode current collector 210 may comprise at least one of copper (Cu), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), aluminum (Al), silver (Ag), and alloys thereof. The thickness of the negative electrode current collector 210 may range from about 1 μm to about 20 μm (e.g., from about 5 μm to about 15 μm, and for example, from about 7 μm to about 10 μm).

[0059] The negative electrode current collector 210 may be composed of or include one of the aforementioned metals, or may include an alloy or cladding material of two or more metals. The negative electrode current collector 210 may have, for example, a plate shape or a foil shape. Alternatively, in the example embodiment, the negative electrode current collector 210 may be omitted.

[0060] The coating layer 220 allows lithium metal to grow between the coating layer 220 and the negative electrode current collector 210 during charging of the cell CEL. The coating layer 220 can form a protective layer for lithium metal and also reduces or inhibits the deposition and growth of lithium dendrites.

[0061] Coating layer 220 may include a metal (or metalloid) and carbon. For example, coating layer 220 may include at least one metal (or metalloid) (such as or including at least one of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn)). Coating layer 220 may include at least one carbon (such as or including at least one of carbon black, acetylene black, furnace black, Ketjen black, and graphene). In an example embodiment, coating layer 220 may include a mixture (or composite) of carbon black and silver (Ag).

[0062] The coating layer 220 can be thinner than the positive electrode active material layer 120. The thickness of the coating layer 220 can, for example, range from about 50% or less, about 40% or less, about 30% or less, about 20% or less, about 10% or less, or about 5% or less of the thickness of the positive electrode active material layer 120. The thickness of the coating layer 220 can, for example, range from about 1 μm to about 20 μm, from about 2 μm to about 10 μm, or from about 3 μm to about 7 μm. When the thickness of the coating layer 220 is low (e.g., less than about 1 μm), lithium dendrites formed between the coating layer 220 and the negative electrode current collector 210 may cause the coating layer 220 to collapse, thereby degrading the cycle characteristics of the cell cell (CEL). When the thickness of the coating layer 220 is significantly increased (e.g., greater than 20 μm), the energy density of the cell cell (CEL) may decrease due to the coating layer 220, and the internal resistance of the cell cell (CEL) may increase, which may reduce the cycle characteristics of the cell cell (CEL).

[0063] For example, although not shown, a carbon layer may be further included to improve the adhesion between the coating layer 220 and the solid electrolyte layer 300.

[0064] Although not shown, as another example of this disclosure, the areas of the positive electrode layer 100 and the negative electrode layer 200 in the cell CEL of an all-solid-state battery may be different from each other.

[0065] Alternatively, as another example of this disclosure, the solid electrolyte layer 300 in the cell CEL of an all-solid-state battery may include multiple solid electrolyte layers. The areas of the multiple solid electrolyte layers may be the same or different from each other.

[0066] Alternatively, as another example of this disclosure, the cell CEL of an all-solid-state battery may also include a gasket to fill the lateral steps caused by area differences.

[0067] Alternatively, as another example of this disclosure, the cell CEL of the all-solid-state battery may further include a lithium metal layer between the negative electrode current collector 210 and the coating layer 220. During charging of the cell CEL, the lithium metal layer may be formed, or its thickness may be further increased.

[0068] Alternatively, as another example of the present invention, the cell CEL of the all-solid-state battery can be a dual-cell all-solid-state battery in which two different single cells are stacked together. Both different single cells can include all the structures of the negative electrode layer 200, the solid electrolyte layer 300, and the positive electrode layer 100 described above. The two different single cells can be stacked such that the positive electrode current collector is in contact with each other. The two different single cells can be arranged in a vertically symmetrical manner.

[0069] The positive electrode layer 100 according to an exemplary embodiment of the present disclosure is described in more detail below.

[0070] Positive electrode for all-solid-state batteries Reference Figure 1 According to an example of this disclosure, the positive electrode active material layer 120 of the cell CEL of an all-solid-state battery may include a first layer VLY1 and a second layer VLY2. Both the first layer VLY1 and the second layer VLY2 may include a positive electrode active material, a solid electrolyte, a conductive material, and a binder. This is referred to below. Figure 2 Detailed description.

[0071] The first layer VLY1 and the second layer VLY2 can both be located on the positive electrode current collector 110. The first layer VLY1 and the second layer VLY2 can both be in contact with the positive electrode current collector 110. The first layer VLY1 and the second layer VLY2 can both be in contact with the solid electrolyte layer 300 of the cell CEL of the all-solid-state battery. The first layer VLY1 and the second layer VLY2 can be in contact with each other.

[0072] As an example, the first layer VLY1 may include multiple first layers. The second layer VLY2 may include multiple second layers. The multiple first layers and multiple second layers may be alternately set in the horizontal direction (i.e., the first direction D1).

[0073] As an example, the width TKV1 of the first layer VLY1 in the first direction D1 can be substantially equal to the width TKV2 of the second layer VLY2 in the first direction D1. In this specification, substantially equal widths can be defined as the case where the difference between the two widths is within 10%. For example, the width TKV1 of the first layer VLY1 in the first direction D1 can be the same as the width TKV2 of the second layer VLY2 in the first direction D1.

[0074] The width of the first layer VLY1 in the third direction D3 can be substantially equal to the width of the second layer VLY2 in the third direction D3. For example, the width of the first layer VLY1 in the third direction D3 can be the same as the width of the second layer VLY2 in the third direction D3. The width of the first layer VLY1 in the third direction D3 and the width of the second layer VLY2 in the third direction D3 can be the thickness TKP of the positive electrode active material layer 120.

[0075] See below for reference. Figures 8 to 11 As described, the first layer VLY1 and the second layer VLY2 can both be formed by a dry process, and the first layer VLY1 and the second layer VLY2 can be bonded by a pressing process. Then, the first layer VLY1 and the second layer VLY2 can be stacked together, and the stacked material can be slitting or cutting to form the positive electrode active material layer 120. The positive electrode active material layer 120 and the positive electrode current collector 110 can then be laminated to form the positive electrode layer 100.

[0076] Since the first layer VLY1 and the second layer VLY2 can be formed first by a dry process and then bonded together by a pressing process, the interface between the first layer VLY1 and the second layer VLY2 can have an uneven profile. As an example, the interface between the first layer VLY1 and the second layer VLY2 can exist in the form of regions. As an example, the interface between the first layer VLY1 and the second layer VLY2 can include pores. As an example, the interface between the first layer VLY1 and the second layer VLY2 can include voids. As an example, the interface between the first layer VLY1 and the second layer VLY2 can be identified by, for example, electron microscopy, component analysis, etc.

[0077] As an example, since one surface of the positive electrode active material layer 120 in contact with the positive electrode current collector 110 can be formed by a slitting or slicing process, the surface of the first layer VLY1 in contact with the positive electrode current collector 110 and the surface of the second layer VLY2 in contact with the positive electrode current collector 110 can be substantially flat. As an example, since one surface of the positive electrode active material layer 120 in contact with the solid electrolyte layer 300 can be formed by a slitting or slicing process, the surface of the first layer VLY1 in contact with the solid electrolyte layer 300 and the surface of the second layer VLY2 in contact with the solid electrolyte layer 300 can be substantially flat.

[0078] Figure 2 This is an enlarged view depicting the positive electrode active material layer 120 according to an example of this disclosure, and is Figure 1 An enlarged view of region "M" in the image.

[0079] The positive electrode active material layer 120 according to an example of this disclosure may include: positive electrode active materials AM1 and AM2; solid electrolytes SE1 and SE2; a conductive material; and a binder. The positive electrode active materials AM1 and AM2 in the positive electrode active material layer 120 can provide the primary pathways for electron conduction. The solid electrolytes SE1 and SE2 in the positive electrode active material layer 120 can provide the primary pathways for lithium ion conduction.

[0080] The total content of positive electrode active materials AM1, AM2 and solid electrolytes SE1, SE2 in the positive electrode active material layer 120 can be in the range of about 97 parts by weight to about 99.5 parts by weight, relative to 100 parts by weight of positive electrode active materials AM1, AM2, solid electrolytes SE1, SE2, conductive materials and binders.

[0081] The positive electrode active material layer 120 may include about 60 parts by weight to about 92 parts by weight of positive electrode active materials AM1 and AM2, solid electrolytes SE1 and SE2, conductive materials and binders, relative to 100 parts by weight of positive electrode active materials AM1 and AM2.

[0082] Based on 100 parts by weight of the positive electrode active materials AM1, AM2, solid electrolytes SE1, SE2, conductive materials and binder, the positive electrode active material layer 120 may include about 0.5 parts by weight to about 2 parts by weight of binder.

[0083] The positive electrode active material layer 120 may include about 0 to about 2 parts by weight of conductive material relative to 100 parts by weight of the total positive electrode active materials AM1, AM2, solid electrolytes SE1, SE2, conductive material, and binder. For example, the positive electrode active material layer 120 may not include any conductive material.

[0084] In the positive electrode active material layer 120 according to the example of this disclosure, the first layer VLY1 may include a first positive electrode active material AM1, a first solid electrolyte SE1, a conductive material, and a binder. The descriptions of the first positive electrode active material AM1, the first solid electrolyte SE1, the conductive material, and the binder are respectively consistent with those referenced above. Figure 1 The descriptions of the positive electrode active material, solid electrolyte, conductive material, and binder of the positive electrode active material layer 120 are identical.

[0085] The second layer VLY2 may include a second positive electrode active material AM2, a second solid electrolyte SE2, a conductive material, and a binder. The descriptions of the second positive electrode active material AM2, the second solid electrolyte SE2, the conductive material, and the binder are the same as those referenced above. Figure 1 The descriptions of the positive electrode active material, solid electrolyte, conductive material, and binder of the positive electrode active material layer 120 are identical.

[0086] The first positive electrode active material AM1 may be the same as or different from the second positive electrode active material AM2. The first solid electrolyte SE1 may be the same as or different from the second solid electrolyte SE2. The conductive material and binder in the first layer VLY1 may be the same as or different from the conductive material and binder in the second layer VLY2.

[0087] The first layer VLY1 can be or includes a layer with a relatively high content of positive electrode active material. The content of the first positive electrode active material AM1 in the first layer VLY1 can be greater than the content of the second positive electrode active material AM2 in the second layer VLY2. By including a relatively large amount of the first positive electrode active material AM1, the first positive electrode active material AM1 can be continuously arranged or distributed in the thickness direction (third direction D3) of the first layer VLY1. The electron movement path in the first layer VLY1 can be almost uninterrupted and can be formed as a relatively straight line. The first layer VLY1 can relatively provide the main path for conducting electrons through it.

[0088] The second layer VLY2 can be or includes a layer with a relatively high content of solid electrolyte. The content of the second solid electrolyte SE2 in the second layer VLY2 can be greater than the content of the first solid electrolyte SE1 in the first layer VLY1. By including a relatively large amount of the second solid electrolyte SE2, the second solid electrolyte SE2 can be continuously arranged or distributed in the thickness direction (third direction D3) of the second layer VLY2. The movement path of lithium ions in the second layer VLY2 can be almost continuous and can be formed as a relatively straight line. The second layer VLY2 can relatively provide the main path for lithium ion conduction.

[0089] As an example, the weight ratio of the first positive electrode active material AM1 to the first solid electrolyte SE1 in the first layer VLY1 can be in the range of about 6:4 to about 9.5:0.5, about 8:2 to about 9.5:0.5, about 8.5:1.5 to about 9.5:0.5, or about 9:1. The weight ratio of the second positive electrode active material AM2 to the second solid electrolyte SE2 in the second layer VLY2 can be in the range of about 6:4 to about 9.5:0.5, about 6:4 to about 8:2, about 6.5:3.5 to about 7.5:2.5, or about 7:3.

[0090] Return to reference Figure 1 The thickness TKP of the positive electrode active material layer 120 in the third-direction D3 according to the examples of this disclosure can be in the range of about 40 μm or greater. The positive electrode active material layer 120 according to this disclosure can also be fabricated in the form of a thick film. For example, the thickness TKP of the positive electrode active material layer 120 in the third-direction D3 can be in the range of about 40 μm or greater, about 110 μm or greater, or about 180 μm or greater, and can be about 1 mm or less, about 500 μm or less, or about 300 μm or less.

[0091] The loading level of the positive electrode layer 100 can be approximately 20 mg / cm². 2 Or within a wider range. The positive electrode active material layer 120 according to the examples of this disclosure can also be fabricated in the form of a thick film. For example, the loading level of the positive electrode layer 100 can be about 20 mg / cm³. 2 Or larger or about 25 mg / cm 2 Or within a wider range, and can also be approximately 200 mg / cm³ 2 Or smaller or about 100 mg / cm 2 Or even smaller. The positive electrode loading level can refer to the mass of the positive electrode active material layer coated on a unit area of ​​positive electrode current collector.

[0092] The positive electrode layer 100 and cell CEL of the all-solid-state battery according to an example embodiment of the present disclosure may have the following characteristics.

[0093] In the first layer VLY1 and the second layer VLY2 constituting the positive electrode active material layer 120 according to the example of this disclosure, the electron movement path and the lithium ion movement path can be almost uninterrupted and can be simplified. When the positive electrode active material layer 120 includes both the first layer VLY1 providing the main path for electron conduction and the second layer VLY2 providing the main path for lithium ion conduction, both the electronic conductivity and ionic conductivity of the positive electrode layer 100 can be increased. The positive electrode active material layer 120 can reduce or prevent overvoltage of the positive electrode layer 100. When the positive electrode active material layer 120 includes the first layer VLY1 and the second layer VLY2, the region in the positive electrode active material layer 120 that can substantially participate in the movement of electrons and / or lithium ions can be increased. The positive electrode active material layer 120 can increase the reversible capacity of the positive electrode layer 100.

[0094] The positive electrode active material layer 120 according to the examples of this disclosure can be in the form of a thick film. Even when the positive electrode active material layer 120 is in the form of a thick film, the positive electrode layer 100 according to this disclosure can have desired or improved electronic and ionic conductivity, can reduce or prevent overvoltage, and can have relatively high reversible capacity.

[0095] The cell CEL of the all-solid-state battery according to the example of this disclosure can have high capacity and high output characteristics by including the above-described positive electrode active material layer 120.

[0096] In the example embodiments described below, references to the above are omitted. Figure 1 and Figure 2 The technical features described are repeated in detail, and the differences are also described in detail.

[0097] Reference Figure 3 In the positive electrode active material layer 120 according to an example of the present disclosure, the first layer VLY1 may include a plurality of first layers VLY1. Any one of the plurality of first layers VLY1 may have a width different from the width of each or at least one of the remaining first layers VLY1. As an example, the width TKVC1 of any one of the plurality of first layers VLY1 in the first direction D1 may be greater than the width TKV1 of each of the remaining first layers VLY1 in the first direction D1. For example, the width TKVC1 may be in the range of about 1.2 times to about 2.5 times the width TKV1.

[0098] Any one of the multiple first layers VLY1 can have a width different from the width of the second layer VLY2. For example, the width TKVC1 of any of the multiple first layers VLY1 in the first direction D1 can be greater than the width TKV2 of the second layer VLY2 in the first direction D1. For example, the width TKVC1 can be in the range of about 1.2 times to about 2.5 times the width TKV2.

[0099] For example, an example of this embodiment can be found by referring to the following. Figure 12 and Figure 13 The manufacturing method described is used to manufacture it.

[0100] Reference Figure 4 In the positive electrode active material layer 120 according to the example of this disclosure, the second layer VLY2 may include a plurality of second layers VLY2. Any one of the plurality of second layers VLY2 may have a width different from the width of each or at least one of the remaining second layers VLY2. For example, the width TKVC2 of any one of the plurality of second layers VLY2 in the first direction D1 may be greater than the width TKV2 of each or at least one of the remaining second layers VLY2 in the first direction D1. For example, the width TKVC2 may be in the range of about 1.2 times to about 2.5 times the width TKV2.

[0101] Any one of the multiple second layers VLY2 can have a width different from the width of the first layer VLY1. As an example, the width TKVC2 of any of the multiple second layers VLY2 in the first direction D1 can be greater than the width TKV1 of the first layer VLY1 in the first direction D1. For example, the width TKVC2 can be in the range of about 1.2 times to about 2.5 times the width TKV1.

[0102] For example, an example of this embodiment can be found by referring to the following. Figure 12 and Figure 13 The manufacturing method described is used to manufacture it.

[0103] Reference Figure 5 In the positive electrode active material layer 120 according to the example of this disclosure, the first layer VLY1 may include a plurality of first layers VLY1. Most of the plurality of first layers VLY1 may have a relatively large width TKVC1. The second layer VLY2 may include a plurality of second layers VLY2. Most of the plurality of second layers VLY2 may have a relatively large width TKVC2.

[0104] For example, any one of the plurality of first layers VLY1 may have a width different from each or at least one of the remaining first layers VLY1. For example, the width TKV1 of any one of the plurality of first layers VLY1 in the first direction D1 may be smaller than the width TKVC1 of each of the remaining first layers VLY1 in the first direction D1. For example, the width TKVC1 may be in the range of about 1.2 times to about 2.5 times the width TKV1. Any one of the plurality of first layers VLY1 may be present at the end of the positive electrode active material layer 120.

[0105] For example, any one of the plurality of second layers VLY2 may have a width different from each or at least one of the remaining second layers VLY2. For example, the width TKV2 of any one of the plurality of second layers VLY2 in the first direction D1 may be smaller than the width TKVC2 of each or at least one of the remaining second layers VLY2 in the first direction D1. For example, the width TKVC2 may be in the range of about 1.2 times to about 2.5 times the width TKV2. Any one of the plurality of second layers VLY2 may be present at the end of the positive electrode active material layer 120.

[0106] For example, the width TKVC1 of each of the remaining first-layer VLY1s in the plurality of first-layer VLY1s can be substantially the same as the width TKVC2 of each of the remaining second-layer VLY2s in the plurality of second-layer VLY2s.

[0107] For example, an example of this embodiment can be found by referring to the following. Figure 14 and Figure 15 The manufacturing method described is used to manufacture it.

[0108] Figure 6 This is a cross-sectional view of a cell (CEL) of an all-solid-state battery according to a comparative example of this disclosure. Figure 7 It is a diagram depicting the positive electrode layer 100 according to a comparative example of this disclosure, and is Figure 6 An enlarged view of region "N" in the image.

[0109] Reference Figure 6 and Figure 7 According to the comparative example of this disclosure, the positive electrode active material layer 120 may include a third positive electrode active material AM3, a third solid electrolyte SE3, a conductive material, and a binder. The third positive electrode active material AM3, the third solid electrolyte SE3, the conductive material, and the binder are similar to those described above. Figure 1The positive electrode active material, solid electrolyte, conductive material, and binder of the described positive electrode active material layer 120 are identical. The third positive electrode active material AM3 may be the same as or different from the first positive electrode active material AM1 and / or the second positive electrode active material AM2. The third solid electrolyte SE3 may be the same as or different from the first solid electrolyte SE1 and / or the second solid electrolyte SE2.

[0110] The weight ratio of the third positive electrode active material AM3 to the third solid electrolyte SE3 in the positive electrode active material layer 120 can be in the range of about 6:4 to about 9.5:0.5, about 6.5:3.5 to about 9:1, about 7:3 to about 9:1, about 7.5:2.5 to about 8.5:1.5, or about 8:2. The positive electrode active material layer 120 can be manufactured by mixing the third positive electrode active material AM3 and the third solid electrolyte SE3 in a specific weight ratio within the above-mentioned weight ratio range. That is, the positive electrode active material layer 120 according to the comparative example of this disclosure can be or include a layer comprising the third positive electrode active material AM3 and the third solid electrolyte SE3 in a given weight ratio.

[0111] In the positive electrode active material layer 120 according to the comparative example of this disclosure, the third positive electrode active material AM3 and the third solid electrolyte SE3 may be randomly or non-systematically distributed. In the positive electrode active material layer 120, the third positive electrode active material AM3 and the third solid electrolyte SE3 may be relatively irregularly distributed.

[0112] In the positive electrode active material layer 120 of the comparative example according to this disclosure, the third positive electrode active material AM3 may not be continuously arranged in the thickness direction (third direction D3), and may be distributed relatively irregularly. Therefore, the movement path of electrons in the positive electrode active material layer 120 may be interrupted, or may have a relatively complex profile.

[0113] In the positive electrode active material layer 120 of the comparative example according to this disclosure, the third solid electrolyte SE3 may not be arranged continuously in the thickness direction (third direction D3), but may be distributed relatively irregularly. Therefore, the movement path of lithium ions in the positive electrode active material layer 120 may be interrupted or may have a relatively complex profile.

[0114] The positive electrode active material layer 120 according to the comparative example of this disclosure may include a relatively large number of inactive regions. That is, the positive electrode active material layer 120 may include a relatively large number of regions that may not substantially participate in the movement of electrons and / or lithium ions.

[0115] The positive electrode layer 100 according to the comparative example of this disclosure may have relatively low electronic conductivity and ionic conductivity. The positive electrode layer 100 according to the comparative example of this disclosure may generate overvoltage or may have relatively high irreversible capacity.

[0116] The positive electrode active material layer 120 according to the comparative example of this disclosure can be a thick film. When the positive electrode active material layer 120 is in the form of a thick film, the above-mentioned problems may occur more severely.

[0117] Method for manufacturing positive electrodes for all-solid-state batteries Figures 8 to 11 This is a perspective view illustrating a method for manufacturing a positive electrode for an all-solid-state battery according to an exemplary embodiment of the present disclosure.

[0118] A method for manufacturing a positive electrode for an all-solid-state battery according to an example embodiment of the present disclosure may include: forming a unit active material layer including a first layer and a second layer by a dry process; forming a stack of unit active material layers; performing a slicing process on the stack to form a positive electrode active material layer; and laminating the positive electrode active material layer onto a positive electrode current collector.

[0119] Reference Figure 8 The unit active material layer UNL, including a first layer VLY1 and a second layer VLY2, may include a first layer VLY1 and a second layer VLY2 on top of the first layer VLY1. (As mentioned above...) Figure 2 As described, the first layer VLY1 may include a first positive electrode active material AM1 and a first solid electrolyte SE1. As mentioned above, the second layer VLY2 may include a second positive electrode active material AM2 and a second solid electrolyte SE2.

[0120] Unit active material layers (UNLs) can be formed using a dry process. Forming UNLs using a dry process may include: forming a first layer (VLY1) using a dry process; forming a second layer (VLY2) using a dry process; and performing a pressing process on the first layer (VLY1) and the second layer (VLY2).

[0121] Forming the first layer VLY1 by a dry process may include: dry mixing a first positive electrode active material AM1, a first solid electrolyte SE1, a conductive material and a binder to form a dry mixture; and forming a membrane of the dry mixture.

[0122] Forming a second layer VLY2 by a dry process may include: dry mixing a second positive electrode active material AM2, a second solid electrolyte SE2, a conductive material and a binder to form a dry mixture; and forming a membrane of the dry mixture.

[0123] Dry mixing can refer to mixing without the presence of process solvents. Process solvents can be or include, for example, solvents used to prepare electrode slurries. Process solvents can be or include, for example, water, N-methylpyrrolidone (NMP), etc., but are not limited to, and are not restricted to, as long as the solvent is a process solvent used in the production of the electrode slurry.

[0124] Dry mixing can be performed using a mixer. The mixer can be, for example, a kneader. The mixer may include, for example, a chamber, one or more rotating shafts disposed within the chamber, and blades coupled to the rotating shafts for rotatability, the blades being arranged along the length of the rotating shafts. The blades can be, for example, one or more of ribbon blades, sigma blades, jet (Z) blades, dispersing blades, and helical blades. By including the blades, the positive electrode active material AM1 or AM2, the solid electrolyte SE1 or SE2, the conductive material, and the binder can be effectively mixed without solvents. For example, a dough-like dry mixture can be prepared.

[0125] For example, one or more dry mixing processes can be performed. First, a mixture can be prepared by dry mixing the positive electrode active material AM1 or AM2, the solid electrolyte SE1 or SE2, the conductive material, and the binder. The positive electrode active material AM1 or AM2, the solid electrolyte SE1 or SE2, the conductive material, and the binder can be substantially uniformly mixed through the first dry mixing. Then, a fibrillation process can be performed via kneading. By performing the fibrillation process via kneading, the binder (e.g., PTFE, etc.) can be fibrillated, and a dry mixture containing the binder can be obtained.

[0126] For example, plasticizers or pore-forming agents can be added to the dry mixture to form pores inside the first layer VLY1 or the second layer VLY2.

[0127] The resulting dry mixture can be formed into a film to form a first layer VLY1 or a second layer VLY2. For example, the dry mixture can be introduced from a feeder into an extrusion apparatus and extruded in the form of a sheet or film. For example, the extrusion apparatus may include a pair of rollers. The dry mixture can be introduced between the pair of rollers. Thus, a first layer VLY1 or a second layer VLY2 in the form of a film can be formed. For example, the first layer VLY1 or the second layer VLY2 can be or include a standing membrane.

[0128] The formed first layer VLY1 and second layer VLY2 can be stacked together, and a pressing process can be performed on the first layer VLY1 and second layer VLY2 to form a unit active material layer UNL. For example, a pair of rollers can be used to perform the pressing process. For example, a pair of rollers heated to suitable temperature conditions can be used for the pressing process. Through the pressing process, the first layer VLY1 and the second layer VLY2 can be bonded to each other. For example, the unit active material layer UNL can be or includes a self-standing membrane.

[0129] The interface between the first layer VLY1 and the second layer VLY2 can have an uneven profile. For example, the interface between the first layer VLY1 and the second layer VLY2 can exist in the form of regions. For example, the interface between the first layer VLY1 and the second layer VLY2 can include pores. For example, the interface between the first layer VLY1 and the second layer VLY2 can be identified by electron microscopy, component analysis, etc.

[0130] Next, a stack STL in which unit active material layers UNL are laminated can be formed. In this step, the stack STL can be formed by sufficiently stacking the unit active material layers UNL so that the positive electrode active material layer 120 to be formed later can have the desired area.

[0131] Forming a stacked component STL may include performing at least one of a stacking process, a winding process, and a folding process on the unit active material layer UNL.

[0132] As an example embodiment of this disclosure, refer to Figure 9 Stacking processes can be performed on unit active material layers (UNLs) to form a stacked structure (STL). In other words, a stacked structure (STL) can be formed by stacking multiple unit active material layers (UNLs).

[0133] For example, multiple unit active material layers (UNLs) can be stacked together, and a pressing process can be performed on the stacked UNLs to form a stacked part (STL). The pressing process can be performed using a roller press, a flatbed press, etc., but is not limited to these. For example, a pair of rollers can be used to perform the pressing process. For example, a pair of rollers heated to a suitable temperature can be used for the pressing process. Through the pressing process, multiple unit active material layers (UNLs) can be bonded together.

[0134] The interface between multiple unit active material layers (UNLs) can have an uneven profile. For example, the interface between multiple unit active material layers (UNLs) can exist in the form of regions. For example, the interface between multiple unit active material layers (UNLs) can include pores. For example, the interface between multiple unit active material layers (UNLs) can be identified by electron microscopy, component analysis, etc.

[0135] For example, a stacked structure STL can be formed by stacking multiple unit active material layers UNL in a manner that allows the first layer VLY1 and the second layer VLY2 to be stacked alternately.

[0136] Unlike what has been depicted, in another example, a stacked assembly STL can be formed by stacking multiple unit active material layers UNL with the first layer VLY1 of two adjacent unit active material layers UNL facing each other. Alternatively, a stacked assembly STL can be formed by stacking multiple unit active material layers UNL with the second layer VLY2 of two adjacent unit active material layers UNL facing each other.

[0137] Reference Figure 10 The positive electrode active material layer 120 can be formed by performing a slitting or dicing process SLT on the formed stack STL.

[0138] For example, this step may include a vertically stacked material (STL). That is, the positive electrode active material layer 120 can be formed by performing a slitting or dicing process on the vertically stacked material (STL). Verticalization can be achieved by rotating the stacked material (STL) in one direction, such that the side surface of the formed stacked material (STL) becomes the top surface.

[0139] A slitting or dicing process can be performed so that the positive electrode active material layer 120 can have a desired thickness or loading level. In this step, a positive electrode active material layer 120 in the form of a thick film can be formed.

[0140] For example, a stacked STL can be slicing or dicing multiple times. Therefore, multiple positive electrode active material layers 120 can be formed.

[0141] The first layer VLY1 and the second layer VLY2 can be cut together using a slitting or cutting process. At least one surface of the cut first layer VLY1 and at least one surface of the cut second layer VLY2 can be flat. At least one surface of the cut first layer VLY1 and at least one surface of the cut second layer VLY2 can be coplanar.

[0142] Reference Figure 11 The positive electrode active material layer 120 can be laminated onto the positive electrode current collector 110.

[0143] The positive electrode active material layer 120 can be formed and laminated on one or both surfaces of the positive electrode current collector 110. The first layer VLY1 and the second layer VLY2 of the positive electrode active material layer 120 can be laminated to contact the positive electrode current collector 110. The first layer VLY1 and the second layer VLY2 are formed side-by-side on the positive electrode current collector 110. Lamination can be performed using laminating equipment such as a roller press or a flatbed press, or a profile laminating machine (LMP), but is not limited to these methods. For example, lamination can be performed using a pair of rollers R. For example, lamination can be performed using a pair of rollers R heated to suitable temperature conditions.

[0144] Contrary to what is depicted, the positive electrode current collector 110 may also include an adhesive layer on one or both surfaces.

[0145] In the example embodiments described below, references to the above are omitted. Figures 8 to 11 The described technical features are repeated in detail, and the differences are described in more detail.

[0146] Reference Figure 12 and Figure 13 As another example of this disclosure, a stacked assembly STL in which a first layer VLY1 and a second layer VLY2 are stacked can be formed by performing a winding process on the unit active material layer UNL. The first layer VLY1 and the second layer VLY2 can be wound together by the winding process.

[0147] For example, a winding process can be performed on the unit active material layer UNL, and a pressing process can be performed to form a stacked part STL. The pressing process can be performed by a roll press, a flat press, etc., but is not limited to these. For example, a pair of rolls can be used to perform the pressing process. For example, a pair of rolls heated to a suitable temperature can be used for the pressing process. Through the pressing process, the first layer VLY1 and the second layer VLY2 in the unit active material layer UNL can be bonded to each other.

[0148] The interface between the first layer VLY1 and the second layer VLY2 can have an uneven profile. For example, the interface between the first layer VLY1 and the second layer VLY2 can exist in the form of regions. For example, the interface between the first layer VLY1 and the second layer VLY2 can include pores. For example, the interface between the first layer VLY1 and the second layer VLY2 can be identified by electron microscopy, component analysis, etc.

[0149] A slitting or dicing process (SLT) can be performed on the upright stacked material (STL) to allow the positive electrode active material layer 120 to have a desired thickness or load level. Additional slitting or dicing processes (SLT) can be performed to allow the positive electrode active material layer 120 to have a desired area.

[0150] For example, the cell active material layer UNL can be wound in such a way that the second layer VLY2 is inside the formed stack STL and the first layer VLY1 is exposed to the outside in the formed stack STL. Therefore, the positive electrode active material layer 120 can be formed such that the second layer VLY2 can include a plurality of second layers VLY2, and the width TKVC2 of any one of the plurality of second layers VLY2 is greater than the width TKV2 of each of the remaining second layers VLY2 (see...). Figure 4 ).

[0151] Unlike what is depicted, as another example, the cell active material layer UNL can be wound in such a way that the first layer VLY1 is inside the formed stack STL and the second layer VLY2 is exposed to the outside in the formed stack STL. Therefore, the positive electrode active material layer 120 can be formed such that the first layer VLY1 may include a plurality of first layers VLY1, and the width TKVC1 of any one of the plurality of first layers VLY1 is greater than the width TKV1 of each of the remaining first layers VLY1 (see...). Figure 3 ).

[0152] Reference Figure 14 and Figure 15 As another example of this disclosure, a stacked assembly STL in which unit active material layers UNL are stacked can be formed by performing a folding process on the unit active material layers UNL. Through the folding process, the first layer VLY1 and the second layer VLY2 can be folded together.

[0153] For example, a folding process can be performed on the unit active material layer UNL, and a pressing process can be performed to form a stacked part STL. The pressing process can be performed by a roll press, a flat press, etc., but is not limited to these. For example, a pair of rolls can be used to perform the pressing process. For example, a pair of rolls heated to a suitable temperature can be used for the pressing process. Through the pressing process, the first layer VLY1 and the second layer VLY2 in the unit active material layer UNL can be bonded to each other.

[0154] The interface between the first layer VLY1 and the second layer VLY2 can have an uneven profile. For example, the interface between the first layer VLY1 and the second layer VLY2 can exist in the form of regions. For example, the interface between the first layer VLY1 and the second layer VLY2 can include pores. For example, the interface between the first layer VLY1 and the second layer VLY2 can be identified by electron microscopy, component analysis, etc.

[0155] A slitting or dicing process (SLT) can be performed on the upright stacked material (STL) to allow the positive electrode active material layer 120 to have a desired thickness or load level. Additional slitting or dicing processes (SLT) can be performed to allow the positive electrode active material layer 120 to have a desired area.

[0156] Therefore, the positive electrode active material layer 120 can be formed such that the first layer VLY1 can include a plurality of first layers VLY1, and the second layer VLY2 can include a plurality of second layers VLY2, wherein the plurality of first layers VLY1 and the plurality of second layers VLY2 can have a relatively large width (see...). Figure 5 (TKVC1 and TKVC2 in the middle).

[0157] For example, one of the plurality of first layers VLY1 located at the end of the positive electrode active material layer 120 may have a smaller width than the other first layers VLY1 among the plurality of first layers VLY1. For example, the width TKV1 of any one of the plurality of first layers VLY1 may be smaller than the width TKVC1 of each of the remaining first layers VLY1 among the plurality of first layers VLY1 (see Figure 5 ).

[0158] For example, one of the plurality of second layers VLY2 located at the end of the positive electrode active material layer 120 may have a smaller width than the other second layers VLY2 among the plurality of second layers VLY2. For example, the width TKV2 of any one of the plurality of second layers VLY2 may be smaller than the width TKVC2 of each of the remaining second layers VLY2 among the plurality of second layers VLY2 (see Figure 5 ).

[0159] Figure 16 This is a flowchart illustrating a method for manufacturing a positive electrode for an all-solid-state battery according to various example embodiments. In the example, method 1600 includes operations 1610, 1620, 1630, and 1640. Operation 1610 includes forming a unit active material layer by a dry process, the unit active material layer including a first layer and a second layer, the first layer including a first positive electrode active material and a first solid electrolyte, the second layer including a second positive electrode active material and a second solid electrolyte, the second layer being on the first layer. For example, the content of the first positive electrode active material in the first layer is greater than the content of the second positive electrode active material in the second layer, and the content of the second solid electrolyte in the second layer is greater than the content of the first solid electrolyte in the first layer.

[0160] Operation 1620 includes forming a stack in which a first layer and a second layer are arranged alternately in a first direction. For example, forming the stack includes performing at least one of a stacking process, a winding process, and a folding process on the unit active material layers.

[0161] Operation 1630 includes slicing the stack in a second direction intersecting the first direction to form a positive electrode active material layer, wherein slicing the stack includes cutting the first layer and the second layer together.

[0162] Operation 1640 includes laminating a positive electrode active material layer onto a positive electrode current collector, such that the first layer and the second layer are in contact with the positive electrode current collector.

[0163] The method for manufacturing a positive electrode for an all-solid-state battery according to embodiments of the present disclosure can manufacture a positive electrode for an all-solid-state battery in which both electronic conductivity and ionic conductivity are improved. The method for manufacturing a positive electrode for an all-solid-state battery according to embodiments of the present disclosure can also manufacture a positive electrode for an all-solid-state battery having the above-described properties in the form of a thick film.

[0164] The positive electrode for all-solid-state batteries according to embodiments of this disclosure can have desired or improved electronic and ionic conductivity. Furthermore, the positive electrode for all-solid-state batteries according to embodiments of this disclosure can reduce or prevent overvoltage and can have relatively high reversible capacity.

[0165] All-solid-state batteries according to embodiments of this disclosure can have high capacity and high output characteristics.

[0166] As described above, although exemplary embodiments of the invention have been described with reference to the accompanying drawings, the invention can be implemented in other specific forms without altering the technical concept or essential features of the invention. Therefore, it should be understood that the above exemplary embodiments are illustrative in all respects and not restrictive.

Claims

1. A method for manufacturing a positive electrode for an all-solid-state battery, the method comprising the steps of: A unit active material layer is formed by a dry process. The unit active material layer includes a first layer and a second layer. The first layer includes a first positive electrode active material and a first solid electrolyte. The second layer includes a second positive electrode active material and a second solid electrolyte. The second layer is on the first layer. Forming a stack in which the first layer and the second layer are arranged alternately in a first direction; The stack is sliced ​​in a second direction intersecting the first direction to form a positive electrode active material layer. The step of slicing the stack includes cutting the first layer and the second layer together. as well as The positive electrode active material layer is laminated onto the positive electrode current collector, so that the first layer and the second layer are in contact with the positive electrode current collector.

2. The method according to claim 1, wherein, The steps of forming the stacked component include performing at least one of a stacking process, a winding process, and a folding process on the unit active material layer.

3. The method according to claim 1, wherein: The content of the first positive electrode active material in the first layer is greater than the content of the second positive electrode active material in the second layer, and The content of the second solid electrolyte in the second layer is greater than the content of the first solid electrolyte in the first layer.

4. A positive electrode for an all-solid-state battery, the positive electrode comprising: Positive electrode current collector; as well as The positive electrode active material layer is located on the positive electrode current collector. The positive electrode active material layer comprises: a first layer comprising a first positive electrode active material and a first solid electrolyte; and a second layer comprising a second positive electrode active material and a second solid electrolyte, wherein the second layer is in contact with the first layer, and The first layer and the second layer are arranged side by side on the positive electrode current collector.

5. The positive electrode according to claim 4, wherein: The content of the first positive electrode active material in the first layer is greater than the content of the second positive electrode active material in the second layer, and The content of the second solid electrolyte in the second layer is greater than the content of the first solid electrolyte in the first layer.

6. The positive electrode according to claim 4, wherein: The weight ratio of the first positive electrode active material to the first solid electrolyte in the first layer is in the range of 6:4 to 9.5:0.5, and The weight ratio of the second positive electrode active material to the second solid electrolyte in the second layer is in the range of 6:4 to 9.5:0.

5.

7. The positive electrode according to claim 4, wherein: The first layer includes multiple first layers. The second layer includes multiple second layers, and The plurality of first layers and the plurality of second layers are arranged alternately in the horizontal direction.

8. The positive electrode according to claim 4, wherein, The widths of the first layer and the second layer are substantially equal.

9. The positive electrode according to claim 4, wherein: The first layer includes multiple first layers, and Each of the plurality of first layers has a different width from at least one of the plurality of first layers.

10. The positive electrode according to claim 4, wherein: The second layer includes multiple second layers, and Any one of the plurality of second layers has a different width from at least one of the plurality of second layers.

11. The positive electrode according to claim 4, wherein, The loading level of the positive electrode is 20 mg / cm². 2 Or within a larger range.

12. An all-solid-state battery, the all-solid-state battery comprising: A positive electrode layer, a negative electrode layer, and a solid electrolyte layer between the positive electrode layer and the negative electrode layer, wherein: The positive electrode layer includes a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector. The positive electrode active material layer includes: a first layer comprising a first positive electrode active material and a first solid electrolyte; and a second layer comprising a second positive electrode active material and a second solid electrolyte, wherein the second layer is in contact with the first layer, and The first layer and the second layer are arranged side by side on the positive electrode current collector.

13. The all-solid-state battery according to claim 12, wherein, The first layer and the second layer are in contact with the solid electrolyte layer.

14. The all-solid-state battery according to claim 12, wherein: The content of the first positive electrode active material in the first layer is greater than the content of the second positive electrode active material in the second layer, and The content of the second solid electrolyte in the second layer is greater than the content of the first solid electrolyte in the first layer.

15. The all-solid-state battery according to claim 12, wherein: The weight ratio of the first positive electrode active material to the first solid electrolyte in the first layer is in the range of 6:4 to 9.5:0.5, and The weight ratio of the second positive electrode active material to the second solid electrolyte in the second layer is in the range of 6:4 to 9.5:0.

5.

16. The all-solid-state battery according to claim 12, wherein: The first layer includes multiple first layers. The second layer includes multiple second layers, and The plurality of first layers and the plurality of second layers are arranged alternately in the horizontal direction.

17. The all-solid-state battery according to claim 12, wherein, The widths of the first layer and the second layer are substantially equal.

18. The all-solid-state battery according to claim 12, wherein: The first layer includes multiple first layers, and Each of the plurality of first layers has a different width from at least one of the plurality of first layers.

19. The all-solid-state battery according to claim 12, wherein: The second layer includes multiple second layers, and Any one of the plurality of second layers has a different width from at least one of the plurality of second layers.

20. The all-solid-state battery according to claim 12, wherein, The loading level of the positive electrode layer is 20 mg / cm². 2 Or within a larger range.

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