Buffer layer for all-solid-state battery

Abstract

The present invention relates to an all-solid-state battery (ASSB) having an anode containing a first solid electrolyte, a cathode composite containing a second solid electrolyte, a solid electrolyte selected from the group consisting of the first and second solid electrolytes, and at least one buffer layer in contact with the surface of the solid electrolyte. When the solid electrolyte is the first solid electrolyte, one buffer layer is at the interface of the electrolyte with the cathode. When the solid electrolyte is the second solid electrolyte, one buffer layer is at the interface of the electrolyte with the anode. The first electrolyte is selected from a sulfide solid electrolyte and a lithium oxide solid electrolyte, the second electrolyte is a halide solid electrolyte, and the buffer layer has a thickness in the range of 0.5 to less than 10 nm. The present invention further relates to an anode assembly, a cathode assembly, and an electrolyte assembly including at least one buffer layer. The present invention also relates to a method for manufacturing an ASSB or an assembly according to the present invention, in which the buffer layer is deposited by a method based on vapor deposition.

Description

【Technical Field】 【0001】 The present invention belongs to the field of all-solid-state secondary batteries (ASSBs), and particularly relates to individual components such as anodes, cathodes, and solid electrolytes, as well as the interactions between the above components. 【Background Art】 【0002】 ASSBs have received particular attention as alternatives to conventional Li-ion batteries because, among other things, they have relatively few safety concerns and relatively high capacities. 【0003】 To obtain an ASSB, a solid electrolyte is used instead of the liquid electrolyte used in Li-ion batteries. Also, ASSBs use lithium metal anodes and high-energy NMC cathode particles, which are incorporated within the solid electrolyte. 【0004】 Such solid electrolytes are selected from, for example, lithium thiophosphate (β-Li3PS4, LPS), argyrodite (Li6PS5Cl), such as those described in "Li6PS5X: A Lithium-Rich Crystalline Solid with Very High Li+ Mobility" by H.J. Deiseroth et al. (Angew. Chem. Int. Ed., 47 (2008), pp. 755-758), and halides such as Li3InCl6, such as those described below: "Air-Stable Li3InCl6 Electrolytes with High-Voltage Compatibility for All-Solid-State Batteries" by X. Li et al. (Energy Environ. Sci., 2019, 12, pp. 2665-267); "Zur Kristallstruktur von Li3InCl6." by Schmidt, M.O. et al. (Zeitschrift fur Anorg. und Allg. 1999, 625(4), 539-540; and "Handbook of Physics and Chemistry of Rare Earths" by G. Meyer et al. (V. 28, Chapter 177, 2000 Elsevier Sci.). 【0005】 However, the main drawback of these compounds is their chemical and electrochemical interaction with the electrode materials. 【0006】 Halide solid electrolytes are of particular interest because they exhibit good ionic conductivity (over 2 mS / cm), high electrochemical stability against oxidation on the cathode side, and better processability (deformability) than other inorganic solid electrolytes. 【0007】 However, while halide solid electrolytes show good electrochemical tolerance to high-energy NMC cathodes, they are not compatible with lithium metal anodes, particularly lithium metal and Li x Si y which reduce the electrolyte to the metallic state. 【0008】 Also, sulfide electrolytes, while having high ionic conductivity and being compatible with lithium metal anodes, are not electrochemically stable with high-energy NMC cathodes. Therefore, capacity degradation of sulfide-based electrolytes is inevitable during the operation of batteries where the electrolyte is a sulfide electrolyte. 【0009】 Two other disadvantages are associated with sulfide electrolytes: the generation of toxic gas (HS) when the electrolyte is accidentally exposed to moisture, and the low contact surface wetting with NMS particles, which requires the application of a relatively high external compression pressure at all times to maintain the integrity of the pouch-type battery. 【0010】 These chemical and electrochemical interactions result in the rapid degradation of ASSBs. 【0011】 T. Koc, F. Marchini, G. Rousse, R. Dugas, and J.-M. Tarascon addressed the issue of electrode compatibility with the solid electrolyte of ASSBs by creating a heterostructured ion conductor that connects a halide-based cathode, separated from the anode by a relatively stable argyrodite or LPS-type ion conductor at the anode, in the study "Investigation of Solid Electrolyte Layered Oxide Pairs Optimal for the Assembly of Practical All-Solid-State Batteries" (ACS Appl. Energy Mater. 2021, Vol. 4, No. 12, pp. 13575 - 13585, https: / / doi.org / 10.1021 / acsaem.1c02187). 【0012】 However, it has been found that the direct halide-argyrodite interface is unstable, which causes limited cycle performance of ASSBs produced using the above heterostructured electrolyte. 【SUMMARY OF THE INVENTION】 【PROBLEM TO BE SOLVED BY THE INVENTION】 【0013】 Therefore, the present invention proposes to solve the technical problem of preventing rapid degradation of all-solid-state batteries while maintaining high energy capacity during charge and discharge cycles. 【MEANS FOR SOLVING THE PROBLEM】 【0014】 Therefore, according to a first aspect, the present invention relates to an all-solid-state battery having the following:[[]] - An anode including an anode active material and a first solid electrolyte, - A cathode composite including a cathode active material and a second solid electrolyte, - A solid electrolyte including a solid electrolyte material selected from the group consisting of the first and second solid electrolytes, and - At least one buffer layer, particularly one or two buffer layers, in contact with the surface of the solid electrolyte material Here, when the solid electrolyte material is the first solid electrolyte, one buffer layer is at the interface with the cathode composite of the electrolyte. When the solid electrolyte material is the second solid electrolyte, one buffer layer is at the interface with the anode of the electrolyte. Here, the first electrolyte is selected from a sulfide solid electrolyte and a lithium oxide solid electrolyte. Here, the second electrolyte is a halide solid electrolyte. Here, the buffer layer has a thickness in the range of 0.5 to less than 10 nm. 【0015】 According to a second aspect, the present invention also relates to an assembly having the following. - A solid electrolyte including a solid electrolyte material selected from the group consisting of a halide solid electrolyte, a sulfide solid electrolyte, and a lithium oxide solid electrolyte, and - At least one buffer layer, particularly one or two buffer layers, in contact with the surface of the solid electrolyte material. Here, the buffer layer has a thickness in the range of 0.5 to less than 10 nm. 【0016】 This second aspect is also referred to as the "solid electrolyte assembly" hereinafter. 【0017】 According to a third aspect, the present invention further relates to an assembly having the following. - An anode including an anode active material and a solid electrolyte selected from a sulfide solid electrolyte and a lithium oxide solid electrolyte, and - A buffer layer in contact with the surface of the anode composite. Here, the buffer layer has a thickness in the range of 0.5 to less than 10 nm. 【0018】 This third aspect is also called the "anode assembly" hereinafter. 【0019】 According to a fourth aspect, the present invention also relates to an assembly having the following. - A cathode composite including a cathode active material and a halide solid electrolyte, and - A buffer layer that contacts the surface of the cathode composite Here, the buffer layer has a thickness in the range of 0.5 to less than 10 nm. 【0020】 This fourth aspect may be hereinafter referred to as a "cathode assembly". 【0021】 The anode and the cathode are electrodes that are the negative electrode and the positive electrode, respectively, and the above-described third and fourth aspects may be hereinafter collectively referred to as an "electrode assembly". 【0022】 The assembly or all-solid-state battery (ASSB) according to the invention makes it possible to provide an ASSB having a high energy capacity and a relatively good capacity retention rate thereof. 【0023】 Finally, the present invention further relates to a manufacturing process of an all-solid-state battery or an assembly according to the present invention, wherein the buffer layer is formed by a method based on vapor deposition, such as PVD (Physical Vapor Deposition), CVD (Chemical Vapor Deposition), or ALD (Atomic Layer Deposition), preferably by atomic layer deposition, on at least one substrate selected from a solid electrolyte, an anode composite, and a cathode composite. 【Advantages of the Invention】 【0024】 In fact, the buffer layer can provide a physical separation between the electrolyte and an electrode material that is not compatible with the electrolyte, which prevents any direct electrochemical reaction between the above compounds. 【0025】 Furthermore, as is apparent from this specification, the buffer layer implemented according to the present invention has good compatibility with most solid electrolytes, particularly halides and sulfides, and has an acceptable ionic conductivity. 【0026】 The electrical resistance of the buffer layer is particularly advantageous when the thickness of the layer is in the range of 0.5 nm to less than 10 nm. 【0027】 Implementing a gas-phase deposition-based method in the process according to the present invention enables controlling the thickness of the vapor deposition buffer layer. In particular, using atomic layer deposition (ALD) enables providing atomic layers step by step, and thus enables controlling the thickness of the buffer layer very precisely. 【0028】 The present invention makes the most of the characteristics of a sulfide-based electrolyte on the anode side and a halide-based electrolyte on the cathode side. It provides a cost-effective solution and can be easily implemented by known deposition techniques, thereby obtaining a high-capacity all-solid-state battery with a complete long-term durability period. 【Brief Description of the Drawings】 【0029】 【Figure 1】 Figure 1 is a schematic diagram of an embodiment of a procedure for introducing a buffer layer on the surface of a solid electrolyte, including four steps (a), (b), (c), and (d). In step (a), the solid electrolyte powder (1) is pressurized between the movable piston (2) and the fixed piston (2') within the cell body (3). In step (b), the movable piston (2) and the fixed piston (2') are removed to obtain a densified solid electrolyte (1') with a thickness of about 300 μm. In step (c), the buffer layer (4) is processed on the densified solid electrolyte (1') by atomic layer deposition (ALD) technology. At the end of step (c), a buffer layer (4) with a thickness in the range of about 0.5 nm to about 10 nm is obtained. In step (d), the positive electrode (5) is placed on the coated side of the densified solid electrolyte (1'), i.e., the buffer layer (4) side, and the negative electrode (6) is placed on the uncoated side of the densified solid electrolyte (1') to assemble an all-solid-state battery. 【0030】 【Figure 2】 Figure 2 is a Nyquist graph of real impedance (Re(Z), ohm) versus imaginary impedance (Z', ohm), which compares untreated Li6PS5Cl with a Li6PS5Cl solid electrolyte coated with Li3PO4 on one side, where the coated electrolyte has a buffer layer with a thickness of 1 nm. 【0031】 【Figure 3】 Figure 3 shows the electrochemical performance of the cell according to Example 1 of the present invention at room temperature and at C / 20, including Li3PO4 with a thickness of 2 nm in the cases of (a) and (b), and 1 nm in the cases of (c) and (d). (a) and (c) represent galvanostat cycles. (b) and (d) are graphical representations of discharge capacity (milliampere-hours, mAh) versus the number of cycles, indicating the capacity retention rate of the cell. 【0032】 【Figure 4】 Figure 4 represents the electrochemical performance of the cell according to the comparative example at room temperature and at C / 20, both under argon and inside an airtight cell in the ambient atmosphere. (a) represents a galvanostat cycle. (b) is a graphical representation of discharge capacity (milliampere-hours, mAh) versus the number of cycles, showing the change in discharge capacity with respect to the number of cycles inside the cell. 【0033】 【Figure 5】 Figure 5 shows the electrochemical performance of the cell according to Example 2 of the present invention at room temperature and at C / 20, including two buffer layers of Li3PO4 with a thickness of 1 nm. (a) represents the galvanostat cycle of the cell. (b) is a graphical representation of discharge capacity (milliampere-hours, mAh) versus the number of cycles, indicating the capacity retention rate of the cell. 【0034】 【Figure 6】 Figure 6 is a Nyquist graph of real impedance (Re(Z), ohm) versus imaginary impedance (Z’, ohm) for a Li6PS5Cl solid electrolyte coated with a 10-nm-thick buffer layer of Li3PO4, i.e., Comparative Example 2 (Figure 6a), and one of Al2O3, i.e., Comparative Example 3 (Figure 6b). 【0035】 【Figure 7】 Figure 7 shows the galvanostat cycles of the cells according to Comparative Example 2 (Figure 7a) and Comparative Example 3 (Figure 7b). 【BRIEF DESCRIPTION OF THE INVENTION】 【0036】 The assembly or all-solid-state battery according to the present invention includes at least one solid electrolyte selected from the group consisting of a halide solid electrolyte, a sulfide solid electrolyte, and a lithium oxide solid electrolyte, as detailed below. 【0037】 The electrolyte assembly according to the present invention includes a solid electrolyte selected from the group consisting of a halide solid electrolyte, a sulfide solid electrolyte, and a lithium oxide solid electrolyte. 【0038】 The anode assembly according to the present invention includes a solid electrolyte selected from the group consisting of a sulfide solid electrolyte and a lithium oxide solid electrolyte. 【0039】 The cathode assembly according to the present invention includes a halide solid electrolyte. 【0040】 Halide solid electrolyte 【0041】 The halide solid electrolyte can be represented by the following chemical formula. 【Equation】 【0042】 Here, -3 ≤ z ≤ 3, k is the valence of Me, 2 ≤ k < 6, 0 ≤ f ≤ 1; - M includes an alkali metal element, especially Li, - Me includes a metal other than an alkali metal, - X is a halogen. 【0043】 In a specific embodiment, f is different from zero. 【0044】 In certain embodiments, Me may include more than one metal element, and k may be the average value of the sum of the valences of each metal element. For example, when Me contains trivalent and tetravalent elements in equimolar amounts, k = (3 + 4) / 2 = 3.5. In particular, k may be 2, 3, 4, or 5. 【0045】 It is understood that atomic vacancies can exist within the unit cell of the halide solid electrolyte. In this case, the atomic vacancy can be represented as M in the formula of the halide solid electrolyte. 3-z (Me k+ ) f●y X 3-z+k*f where ● represents an atomic vacancy within the unit cell, and y represents the number of atomic positions of the vacancy. In certain embodiments, y can be f*(k - 1). 【0046】 In certain embodiments, examples of M can include Li, Na, K, Rb, Cs, or any combination thereof. For example, examples of M can include at least one of Li and Na, or a combination thereof. In a further aspect, M can consist of at least one alkali metal element. For example, M can consist essentially of at least one alkali metal element selected from the group consisting of Li, Na, K, Rb, and Cs. In another example, M can consist of Li. In yet another example, M can consist of a combination of Li and at least one of Na, K, Rb, and Cs. In yet another example, M can consist of a combination of Na and at least one of Cs and Rb. In another example, M can consist of at least one of Na and Cs. 【0047】 In certain embodiments, Me may include an alkaline earth metal element; a rare earth element; a 3d transition metal; an element selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, Ga; and any combination thereof. For example, Me may include an alkaline earth metal, such as Ba, Mg, Ca, and Sr, or any combination thereof. In another example, Me may include a rare earth element, and in particular, Me may consist of at least one rare earth element. The rare earth element may be selected from Y, Sc, Ce, Gd, Er, La, Yb, and combinations thereof. In a further example, Me may include a 3d transition metal, particularly one selected from Zn, Cu, V, and any combination thereof. In yet another example, Me may include an element selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, Ga, and any combination thereof. 【0048】 In certain embodiments, X may include a halogen, particularly one selected from Cl, Br, I, and any combination thereof. In one example, X may include at least one of Cl and Br. Preferably, X may consist of Cl, Br, or any combination thereof. 【0049】 Accordingly, in embodiments of the present invention, the all-solid-state battery according to the present invention, the cathode assembly according to the present invention, or the electrolyte assembly according to the present invention may include a halide solid electrolyte of the following formula. 【Number】 【0050】 Here, -3 ≤ z ≤ 3, 2 ≤ k < 6, 0 ≤ f ≤ 1; - M includes an alkali metal element, particularly lithium; - Me includes a divalent, trivalent, tetravalent, pentavalent, or hexavalent metal element, or any combination thereof, and in particular, Me is selected from the following: i. Alkaline earth metals, such as Ba, Mg, Ca, Sr, etc., ii. Rare earth elements such as Y, Sc, Ce, Gd, Er, La, Yb, and combinations thereof, iii. 3d transition metals such as Zn, Cu, V, etc., iv. Elements selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, Ga, and v. Any combination thereof, - X is a halogen, particularly selected from Cl, Br, I, and any combination thereof; Preferably, the halide solid electrolyte is Li3InCl6. 【0051】 In certain embodiments, the halide solid electrolyte is Li 3-z Me k+ X 3-z+k and can be represented by. When z is not 0, the complex metal halide can be non-stoichiometric. When z is 0, the complex metal halide can be stoichiometric. For example, -0.95 ≦ z ≦ 0.95. In another example, Me includes Y, Gd, Yb, In, Sc, Zn, Mg, Ca, Ba, Sn, or combinations thereof, and X is Cl, Br, or a combination thereof. 【0052】 In certain embodiments, the solid halide electrolyte can be represented by Li3MeBr6. In another specific embodiment, the solid halide electrolyte can be represented by Li3MeCl6. In these embodiments, Me can consist of at least one of the above-mentioned metal elements and has a valence of 3. Me includes at least one of the above-mentioned metal elements, and the average valence of at least one metal element is 3. 【0053】 In another specific embodiment, the solid halide electrolyte may consist of Li, Y, and at least one of Cl and Br. For example, the solid halide electrolyte may consist of Li, Y, and Cl. In another example, the solid halide electrolyte may consist of Li, Y, and Br. In yet another example, the solid halide electrolyte may consist of Li, Y, Cl, and Br. In a specific example, the solid halide electrolyte is Li 3x Y 1-x Cl3 or Li 3x Y 1-x Br3, where 0 < x ≤ 0.5. 【0054】 In another specific embodiment, the solid halide electrolyte may consist of Li, Gd, and at least one of Cl and Br. For example, the solid halide electrolyte may consist of Li, Gd, and Cl. In another example, the solid halide electrolyte may consist of Li, Gd, and Br. In yet another example, the solid halide electrolyte may consist of Li, Gd, Cl, and Br. In a specific example, the solid halide electrolyte is Li 3x Gd 1-x Cl3 or Li 3x Gd 1-x Br3, where 0.01 ≤ x < 1. 【0055】 In another specific embodiment, the solid halide electrolyte may consist of Li, In, and at least one of Cl and Br. For example, the solid halide electrolyte may consist of Li, In, and Cl. In another example, the solid halide electrolyte may consist of Li, In, and Br. In yet another example, the solid halide electrolyte may consist of Li, In, Cl, and Br. In a specific example, the solid halide electrolyte is Li 3x In 1-x Cl3 or Li 3x In 1-x Br3, where 0 ≤ x < 0.5. 【0056】 Solid halide electrolytes include Li3InCl6, Li3InBr6, Li3YCl6, Li3YBr6, Li 2.7 Y 0.7 Zr 0.3 Cl6, Li 2.8 Y 0.8 Sn 0.2 Cl6, Li 3.2 Y 0.8 Zn 0.2 Cl6, Li 3.2 Y 0.8 Mg 0.2 Cl6, Li3Y 1 / 3 Zr 1 / 3 Mg 1 / 3 Cl6, Li3Y 1 / 3 Sn 1 / 3 Mg 1 / 3 Cl6, Li3Y 1 / 3 Zr 1 / 3 Zn 1 / 3 Cl6, Li 2.95 Na 0.05 YBr6, Li 2.95 K 0.05 YBr6, Li 2.95 Cs 0.05 YBr6, Li3Y 0.7 Gd 0.3 Br6, Li3Y 0.8 Yb 0.2 Br6, Li3Y 0.9 La 0.1 Br6, Li 2.9 Y 0.9 Ce 0.1 Br6, Li3In 0.5 Y 0.5 Cl6, or may be selected from Li3Y(Cl,Br)6. 【0057】 Sulfide solid electrolytes 【0058】 Examples of sulfide solid electrolytes suitable for the present invention may include lithium sulfide, silicon sulfide, phosphorus sulfide, boron sulfide, or combinations thereof. 【0059】 Examples of sulfide solid electrolytes include Li2S-P2S5, Li2S-P2S5-LiX (where X is 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, Li2S-P2S5-Z m S n (where m and n are positive numbers respectively, and Z represents any one of Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (where p and q are positive numbers respectively, and M represents at least one of P, Si, Ge, B, Al, Ga, or In). At least one of these can be mentioned. 【0060】 Sulfide solid electrolytes generally have the general formula Li 7-x PS 6-x X x (where 0 ≤ x ≤ 2 and X is a halogen element) and can be an argyrodite. Preferably, the sulfide solid electrolyte is an argyrodite of the formula Li6PS5Cl. 【0061】 Sulfide solid electrolytes can also be thiophosphoric acids, such as thiol-LISICON, such as (Li) 4-x Ge 1-x P x S4 (where x ranges from 0 to 1), Li7P2S8I, and those selected from Li2S-P2S5, etc. 【0062】 For example, Li2S and P2S5 can be mentioned as sulfide solid electrolytes. When the solid electrolyte material based on sulfides constituting the sulfide solid electrolyte contains Li2S-P2S5, the molar ratio of Li2S and P2S5 can be in the range of, for example, 50:50 to 90:10. 【0063】 Therefore, in an embodiment of the present invention, the all-solid-state battery according to the present invention, the anode assembly according to the present invention, or the electrolyte assembly according to the present invention may include a sulfide solid electrolyte selected from the group consisting of thiophosphate and the argyrodite of the formula Li 7-x PS 6-x X x where 0 ≦ x ≦ 2, X is a halide, particularly selected from Cl, Br, and I, and preferably the first solid electrolyte is selected from argyrodite, and more preferably is Li6PS5Cl. 【0064】 Lithium oxide solid electrolyte 【0065】 Examples of the lithium oxide solid electrolyte suitable for the present invention may include NASICON, perovskite, LISICON, garnet, or a combination thereof. 【0066】 Therefore, in an embodiment of the present invention, the all-solid-state battery according to the present invention, the anode assembly according to the present invention, or the electrolyte assembly according to the present invention may include a lithium oxide solid electrolyte selected from the group consisting of NASICON, such as LiTi2(PO4)3; perovskite, such as (LaLi)TiO3; LISICON, such as Li 14 ZnGe4O 16 , Li4SiO4, or LiGeO4; garnet, such as Li7La3Zr2O 12 and the like, and particularly the lithium oxide solid electrolyte is garnet, and preferably is Li7La3Zr2O 12 . 【0067】 Anode 【0068】 In the all-solid-state battery or anode assembly according to the present invention, the anode includes an anode active material and a solid electrolyte selected from the above-mentioned sulfide solid electrolyte and lithium oxide solid electrolyte. In particular, the anode includes a sulfide solid electrolyte, preferably includes particles composed of a sulfide solid electrolyte. 【0069】 The anode active material is a material that can store and release metal ions, particularly alkali metal ions such as Li ions or Na ions. 【0070】 As the anode active material, metals, carbon, oxides, or nitrides can be used. 【0071】 Metals suitable for use as the anode active material can be single metals or alloys such as lithium metal or lithium alloys. Metals suitable for use as the anode active material can be selected from silicon, tin, silicon compounds, tin compounds, lithium, and lithium alloys. 【0072】 Examples of carbon suitable for use as the anode active material include natural graphite, coke, activated carbon, carbon fiber, spherical carbon, artificial graphite, and amorphous carbon. 【0073】 Therefore, the anode active material is - oxides, - nitrides, - carbon, such as natural graphite, coke, activated carbon, carbon fiber, spherical carbon, artificial graphite, and amorphous carbon, etc., - metals, such as silicon, tin, sodium, or lithium, their compounds and their alloys, etc., In particular, the anode active material is silicon, tin, lithium, their compounds and their alloys, such as Li x In y selected from where x is in the range of 0 to 1 and y is in the range of 0 to 1. Preferably, the anode active material is Li 0.5 In. 【0074】 The anode active material may be present in the form of particles in the ASSB or anode assembly according to the present invention. The median diameter of the anode active material particles may be in the range of 0.1 μm to 100 μm. Preferably, the median diameter of the anode active material particles is larger than the median diameter of the sulfide solid electrolyte particles. 【0075】 The anode is - 50 to 70 wt%, preferably 60 wt% of Li 0.5 In, and - 30 to 50 wt%, preferably 40 wt% of a sulfide solid electrolyte, may include. 【0076】 The thickness of the anode in the ASSB or assembly according to the present invention can be in the range of 10 μm to 500 μm. 【0077】 The buffer layer is deposited on the anode assembly according to the present invention. In particular, the buffer layer deposited on the anode assembly according to the present invention is lithium phosphate, such as Li3PO4, etc., or lithium phosphonitride; NASICON, such as LiTi2(PO4)3, etc.; perovskite, such as (LaLi)TiO3, etc.; LISICON, such as Li 14 ZnGe4O 16 、Li4SiO4, or LiGeO4, etc.; garnet, such as Li7La3Zr2O 12 etc., and includes a buffer material selected from, and particularly consists of, the buffer material; preferably, the buffer layer contains Li3PO4 and particularly consists of Li3PO4. 【0078】 Cathode 【0079】 In the all-solid-state battery or cathode assembly according to the present invention, the cathode composite includes a cathode active material and a halide solid electrolyte as described above. In particular, the cathode may include particles containing a halide solid electrolyte, preferably consisting of a halide solid electrolyte. 【0080】 The cathode active material is a material capable of storing and releasing metal ions, particularly alkali metal ions, such as Li ions or Na ions, etc. 【0081】 As the cathode active material, transition metal fluorides, polyanion materials, polyanion fluoride materials, transition metal sulfides, transition metal oxyfluorides, transition metal oxysulfides, transition metal oxynitrides, and lithium-containing transition metal oxides, doped or undoped, coated or uncoated, can be used. In particular, the cathode active material may be a transition metal oxide, such as lithium cobalt oxide, lithium nickel cobalt aluminum oxide, lithium nickel manganese cobalt oxide, etc. Transition metal oxides suitable for use as the cathode active material are, for example, LiNi 0.6 Mn 0.2 Co 0.2 O2, Li(NiCoAl)O2, and LiCoO2, etc. Preferably, the cathode active material is a transition metal oxide of the formula LiNi 0.6 Mn 0.2 Co 0.2 O2. 【0082】 The cathode active material may be present in the form of particles within the ASSB or cathode assembly according to the present invention. The median diameter of the anode active material particles may range from 0.1 μm to 100 μm. Preferably, the median diameter of the anode active material particles is larger than the median diameter of the solid electrolyte particles (sulfide, halide, or lithium oxide). 【0083】 The cathode composite material - 55 to 75 wt%, particularly 60 to 70 wt%, preferably 66.7 wt%, of the cathode active material, - 20 to 40 wt%, particularly 25 to 30 wt%, preferably 28.6 wt%, of the halide solid electrolyte, and optionally, - 1 to 10 wt%, particularly 2 to 7 wt%, preferably 4.8 wt%, of the electronically conductive carbon compound, may be included. 【0084】 The thickness of the anode in the ASSB or assembly according to the present invention may range from 10 μm to 500 μm. 【0085】 The buffer layer is deposited on the cathode assembly according to the present invention. In particular, the buffer layer deposited on the cathode assembly according to the present invention is lithium phosphate, such as Li3PO4, etc., or lithium phosphonitride; lithium nitride; NASICON, such as LiTi2(PO4)3, etc.; perovskite, such as (LaLi)TiO3, etc.; LISICON, such as Li 14 ZnGe4O 16 , Li4SiO4, or LiGeO4, etc.; and garnet, such as Li7La3Zr2O 12 and the like, and includes a buffer material selected therefrom, and in particular consists of the buffer material; preferably, the buffer layer contains Li3PO4 and in particular consists of Li3PO4. 【0086】 At least one of the anode and the cathode may include an electron conductor compound selected from natural or artificial graphite, graphene, carbon nanotubes, acetylene black, ketjen black, activated carbon, fluorinated carbon, metal powder, conductive whiskers, conductive metal oxides, conductive polymers, metal fibers, or carbon fibers. Preferably, the electron conductor is a vapor-grown carbon fiber. 【0087】 Buffer layer 【0088】 The ASSB or assembly according to the present invention has at least one buffer layer. When the assembly is an electrode assembly according to the present invention, it may have at most one buffer layer. However, in the case of the ASSB or electrolyte assembly according to the present invention, it may have one or two buffer layers. When the article of the present invention has two buffer layers, these layers are in contact with the surfaces facing the two opposite sides of the solid electrolyte constituting the article of the present invention. 【0089】 The buffer layer or the separator layer is intended to prevent a direct electrochemical or chemical reaction between two components of the ASSB according to the present invention. Thus, the buffer layer can prevent such reactions between: a sulfide solid electrolyte and a halide solid electrolyte, between a halide solid electrolyte and an anode, and / or between a sulfide solid electrolyte and a cathode. 【0090】 To meet this requirement, the buffer layer needs to have good electrochemical stability against lithium metal anodes and solid electrolytes, particularly halide solid electrolytes, sulfide solid electrolytes, and lithium oxide solid electrolytes. 【0091】 Therefore, the buffer layer can include oxide-based or fluoride-based compounds that are chemically inert to halide, sulfide, and / or lithium oxide solid electrolytes. 【0092】 In certain embodiments of the present invention, the buffer layer includes metal oxides such as Al2O3, ZnO, ZrO2, TiO2, etc., and preferably, the buffer layer includes Al2O3. 【0093】 In another embodiment of the present invention, the buffer layer is lithium phosphate such as Li3PO4, etc., or lithium phosphonitride; lithium nitride; NASICON such as LiTi2(PO4)3, etc.; perovskite such as (LaLi)TiO3, etc.; LISICON such as Li 14 ZnGe4O 16 , Li4SiO4, or LiGeO4, etc.; garnet such as Li7La3Zr2O 12 and includes ion conductors selected from LiAlO2. 【0094】 Therefore, in the ASSB or assembly according to the present invention, the buffer layer is lithium phosphate such as Li3PO4, etc., or lithium phosphonitride; lithium nitride; NASICON such as LiTi2(PO4)3, etc.; perovskite such as (LaLi)TiO3, etc.; LISICON such as Li 14 ZnGe4O 16 , Li4SiO4, or LiGeO4, etc.; garnet such as Li7La3Zr2O 12and may include a buffer material selected from, for example, Al2O3, and in particular may consist of such a buffer material. More particularly, the buffer layer contains Li3PO4 or Al2O3, and in particular consists of these; preferably, the buffer layer contains Li3PO4 and in particular consists of Li3PO4. 【0095】 In a particular embodiment of the present invention, the buffer layer is lithium phosphate, such as Li3PO4, etc., or lithium phosphonitride; lithium nitride; NASICON, such as LiTi2(PO4)3, etc.; perovskite, such as (LaLi)TiO3, etc.; LISICONL, such as i 14 ZnGe4O 16 , Li4SiO4, or LiGeO4, etc.; and may include a buffer material selected from garnets, such as Li7La3Zr2O 12 and in particular may consist of such a buffer material; preferably, the buffer layer contains Li3PO4 and in particular consists of Li3PO4. 【0096】 Li3PO4 is preferred as a buffer material due to its good compatibility with both sulfide and halide solid electrolytes, as well as its acceptable Li + ionic conductivity. 【0097】 Furthermore, while the ionic conductivity of the buffer layer can be acceptable, it is still lower than that of either sulfide or halide solid electrolytes. 【0098】 However, limiting the thickness of the buffer layer to less than 10 nm makes it possible to prevent the above-mentioned reaction while alleviating the limiting aspects of the ionic conductivity of the buffer layer. 【0099】 In other words, a buffer layer with a thickness of at least 10 nm results in an ASSB with relatively poor electrochemical properties. 【0100】 On the other hand, a buffer layer thinner than 0.5 nm does not sufficiently prevent the reaction between the two components of the ASSB mentioned herein. 【0101】 Therefore, in the ASSB or assembly according to the present invention, the buffer layer has a thickness in the range of 0.5 nm to less than 10 nm. 【0102】 In certain embodiments, the buffer layer has a thickness in the range of 0.75 to 5 nm, preferably 1 to 2 nm. 【0103】 Generation process 【0104】 To meet the requirements for the thickness of the buffer layer in the ASSB or assembly according to the present invention, the buffer layer can be deposited on the surface by a method based on vapor deposition. 【0105】 Examples of such methods based on vapor deposition include, for example, physical vapor deposition (PVD) and chemical vapor deposition (CVD). 【0106】 The buffer layer can also be deposited by atomic layer deposition (ALD). ALD enables specific fine-tuning of the thickness of the buffer layer. 【0107】 Therefore, the present invention also relates to a manufacturing process of an all-solid-state battery or assembly according to the present invention, wherein the buffer layer is deposited on at least one substrate selected from a solid electrolyte, an anode composite, and a cathode composite by a method based on vapor deposition, such as physical vapor deposition method, chemical vapor deposition method, etc., or by atomic layer deposition method, preferably by atomic layer deposition method. 【0108】 In a specific embodiment of the process according to the present invention, the buffer layer is deposited on a powder substrate or a densified substrate. 【0109】 According to this embodiment, the powder substrate can be a component of the assembly or ASSB according to the present invention before its densification. Therefore, the powder substrate can be a solid electrolyte, an anode, and / or a cathode composite. 【0110】 When a buffer material is deposited on a powder substrate, a coated powder substrate is obtained. When the coated powder substrate is densified, the buffer material forms a buffer layer on at least one surface of the obtained densified material. 【0111】 To provide lithium in the buffer layer, for example, when the buffer layer is Li3PO4, a precursor of the formula LiOR where R is C1-C6 alkyl may be used as the precursor, preferably lithium tert-butoxide is used as the precursor for providing lithium. 【0112】 To provide phosphate in the buffer layer, for example, when the buffer layer is Li3PO4, a precursor of the formula OP(OR)3 where R is C1-C3 alkyl may be used as the precursor, preferably OP(OCH3)3 is used as the precursor. 【0113】 To provide aluminum in the buffer layer, for example, when the buffer layer is Al2O3, a precursor of the formula AlR3 where R is C1-C3 alkyl may be used as the precursor, preferably Al(CH3)3 is used as the precursor. 【0114】 To supply oxygen in the buffer layer, for example, when the buffer layer is Al2O3, ozone may be used as the precursor. 【0115】 In a particular embodiment of the present invention, the buffer layer is deposited by atomic layer deposition, and the atomic layer deposition reactor is set to the following temperatures: - In the range of 85°C to 185°C, particularly in the range of 100°C to 170°C, preferably 150°C, or, - In the range of 200°C to 400°C, particularly in the range of 250°C to 350°C, preferably 300°C. 【0116】 The electrodes and electrolytes of the ASSB or assembly according to the present invention are produced according to processes known to those skilled in the art and are illustrated in the following examples. 【Examples】 【0117】 Comparative Example 1 【0118】 Synthesis of Solid Sulfide Electrolyte 【0119】 Li6PS5Cl was synthesized by heat - treating a stoichiometric mixture of Li2S, P2S5 and LiCl in an Al2O3 crucible. 【0120】 The powder mixture was placed in a crucible, vacuum - sealed in a quartz tube, and finally annealed at 550 °C at a heating rate of 5 °C / min for 72 hours, and then naturally cooled to room temperature. 【0121】 Synthesis of Solid Halide Electrolyte 【0122】 Li3InCl6 was produced by dissolving InCl3 and LiCl in distilled water. The precursor was left standing with continuous stirring overnight at room temperature, and the resulting transparent solution was naturally dried at 100 °C. 【0123】 A white powder was obtained, which was then dried first at 100 °C for 24 hours, then at 200 °C for 24 hours under dynamic vacuum (P < 1 mbar), and then naturally cooled to room temperature. 【0124】 Synthesis of Cathode Composite 【0125】 The cathode composite was produced by grinding a mixture of LiNi0.6Mn0.2Co0.2O2 (NMC622):Li3InCl6:VGCF (weight ratio 70:30:5) with a hammer mill. 【0126】 Assembly of Battery 【0127】 The battery assembly was carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two stainless - steel pistons with a diameter of 8 mm. 【0128】 The assembly procedure was carried out in a glove box under an argon atmosphere ([O2] < 1 ppm, [H2O] < 1 ppm). 【0129】 The two electrode cells were assembled as follows. 【0130】 16 - 18 mg / cm 2 The cathode composite (NMC622 / Li3InCl6 / VGCF) of was spread on the surface of the Li6PS5Cl solid electrolyte, and then a mixture of Li0.5In and Li6PS5Cl (weight ratio 60:40) was added to the opposite side of the Li6PS5Cl solid electrolyte pellet as the counter electrode. 【0131】 Finally, the entire stack was further densified at 4 t / cm 2 for 15 minutes. After compression, a pressure of 1 t / cm 2 was applied to the fully assembled cell for electrochemical research. 【0132】 Example 1 according to the present invention 【0133】 The solid sulfide electrolyte, solid halide electrolyte, and cathode composite were produced as described above for Comparative Example 1. 【0134】 Atomic layer deposition 【0135】 A nanometer - thick Li3PO4 film was grown in a Picosun R200 advanced ALD reactor under an argon pressure of around 2 mbar. Argon was used as the carrier gas and purge gas. 【0136】 Lithium tert - butoxide (LiOtBu) and trimethyl phosphate (TMPO) precursors were used as the raw materials for lithium and phosphoric acid, respectively. The LiOtBu precursor was purchased from Strem Chemicals (purity 98%), and the TMPO precursor was purchased from Sigma - Aldrich (purity 99%). The applied sublimation temperatures were 185°C and 85°C, respectively. 【0137】 The temperature of the ALD reactor was set to 150 °C, and the number of ALD cycles was changed to adjust the thickness of the buffer layer. 17 ALD cycles were performed to obtain a buffer layer with a thickness of 1 nm. 34 ALD cycles were performed to obtain a buffer layer with a thickness of 2 nm. 【0138】 TMPO and LiOtBu were pulse-injected into the chamber alternately with pulse times of 6 seconds and 3 seconds, respectively, separated by an 8-second argon purge. 【0139】 A Li6PS5Cl solid electrolyte pellet with one side coated with Li3PO4 was obtained. 【0140】 Battery assembly 【0141】 Battery assembly was carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two stainless steel pistons with a diameter of 8 mm. 【0142】 The assembly procedure was carried out under an argon atmosphere ([O2] < 1 ppm, [H2O] < 1 ppm) in a glove box. 【0143】 Two electrode cells were assembled as follows. 【0144】 16 - 18 mg / cm 2 of the cathode composite (NMC622 / Li3InCl6 / VGCF) was spread on the Li3PO4-coated surface of the Li6PS5Cl solid electrolyte, and then a mixture of Li0.5In and Li6PS5Cl (weight ratio 60:40) was added as a counter electrode to the uncoated side of the Li6PS5Cl solid electrolyte pellet. 【0145】 Finally, the entire stack was further densified at 4 t / cm 2 for 15 minutes. After compression, a pressure of 1 t / cm 2 was applied to the fully assembled cell for electrochemical research. 【0146】 Comparative Example 2 【0147】 A solid sulfide electrolyte, a solid halide electrolyte, and a cathode composite were produced as described above for Comparative Example 1. 【0148】 Atomic layer deposition 【0149】 A nanometer-thick Li3PO4 film was grown in a Picosun R200 advanced ALD reactor under an argon pressure of around 2 mbar. Argon was used as the carrier gas and purge gas. 【0150】 Lithium tert-butyl (LiOtBu) and trimethyl phosphate (TMPO) precursors were used as raw materials for lithium and phosphate, respectively. The LiOtBu precursor was purchased from Strem Chemicals (purity 98%), and the TMPO precursor was purchased from Sigma-Aldrich (purity 99%). The applied sublimation temperatures were 185°C and 85°C, respectively. 【0151】 The temperature of the ALD reactor was set to 150°C, and the growth rate was 0.6 angstroms per cycle. In this way, 167 cycles were performed to obtain a 10-nm-thick buffer layer. 【0152】 TMPO and LiOtBu were alternately pulse-injected into the chamber at respective pulse times of 6 seconds and 3 seconds, separated by an 8-second argon purge. 【0153】 A Li6PS5Cl solid electrolyte pellet was obtained, one side of which was coated with a 10-nm buffer layer of Li3PO4. 【0154】 Battery assembly 【0155】 Battery assembly was carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two stainless steel pistons with a diameter of 8 mm. 【0156】 The assembly procedure was carried out under an argon atmosphere ([O2] < 1 ppm, [H2O] < 1 ppm) in the glove box. 【0157】 Two electrode cells were assembled as follows. 【0158】 16 - 18 mg / cm 2 of the cathode composite (NMC622 / Li3InCl6 / VGCF) was spread on the Li3PO4 - coated surface of the Li6PS5Cl solid electrolyte, and then a mixture of Li0.5In and Li6PS5Cl (weight ratio 60:40) was added as the counter - electrode on the uncoated side of the Li6PS5Cl solid electrolyte pellet. 【0159】 Finally, the entire stack was further densified at 4 t / cm 2 for 15 minutes. After compression, a pressure of 1 t / cm 2 was applied to the fully assembled cell for electrochemical research. 【0160】 Example 2 according to the present invention 【0161】 The solid sulfide electrolyte, solid halide electrolyte, and cathode composite were produced as described above for Comparative Example 1. 【0162】 Atomic layer deposition 【0163】 A nanometer - thick Li3PO4 film was grown in a Picosun R200 advanced ALD reactor under an argon pressure of around 2 mbar. Argon was used as the carrier gas and purge gas. 【0164】 Lithium tert - butyl (LiOtBu) and trimethyl phosphate (TMPO) precursors were used as the raw materials for lithium and phosphate, respectively. The LiOtBu precursor was purchased from Strem Chemicals (purity 98%), and the TMPO precursor was purchased from Sigma - Aldrich (purity 99%). The applied sublimation temperatures were 185 °C and 85 °C, respectively. 【0165】 The temperature of the ALD reactor was set at 300 °C, and the growth rate was 0.6 Å per cycle. In this way, 17 cycles were carried out to obtain a buffer layer with a thickness of 1 nm. 【0166】 TMPO and LiOtBu were pulse-injected into the chamber alternately with pulse times of 6 seconds and 3 seconds, respectively, separated by an 8-second argon purge. 【0167】 A Li6PS5Cl solid electrolyte pellet coated with Li3PO4 on two opposite-facing surfaces was obtained. 【0168】 Assembly of the battery 【0169】 The assembly of the battery was carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two stainless steel pistons with a diameter of 8 mm. 【0170】 Two electrode cells were assembled as follows. 【0171】 16 - 18 mg / cm 2 of the cathode composite (NMC622 / Li3InCl6 / VGCF) was spread on the first Li3PO4-coated surface of the Li6PS5Cl solid electrolyte pellet, and then a mixture of Li0.5In and Li6PS5Cl (weight ratio 60:40) was added as a counter electrode on the side of the Li6PS5Cl solid electrolyte pellet opposite to its Li3PO4-coated side. 【0172】 Finally, the entire stack was further densified at 4 t / cm 2 for 15 minutes. After compression, a pressure of 1 t / cm 2 was applied to the fully assembled cell for electrochemical research. 【0173】 The assembly procedure was carried out in an argon atmosphere ([O2] < 1 ppm, [H2O] < 1 ppm) in a glove box. 【0174】 Example 3 according to the present invention 【0175】 A solid sulfide electrolyte, a solid halide electrolyte, and a cathode composite material were produced in the same manner as described above for Comparative Example 1. 【0176】 Atomic layer deposition 【0177】 A nanometer-thick Al2O3 film was grown in a Picosun R200 advanced ALD reactor under an argon pressure of around 2 mbar. Argon was used as the carrier gas and purge gas. 【0178】 Trimethylaluminum (TMA) and ozone (O3) precursors were used as aluminum and oxygen sources, respectively. The TMA precursor was purchased from STREM Chemical (purity 98%), and the O3 precursor was synthesized using a mixed gas of 99.5% O2 and 0.5% N2 with a USA Inc. ozone AC series generator model AC-Bench 2025. 【0179】 The temperature of the ALD reactor was set to 150 °C, and the growth rate was 1.4 angstroms per cycle. In this way, 7 cycles were performed to obtain a buffer layer with a thickness of 1 nm. 【0180】 TMA and O3 were alternately pulse-injected into the chamber with pulse times of 0.3 seconds and 0.5 seconds, respectively, separated by a 5-second argon purge. 【0181】 A Li6PS5Cl solid electrolyte pellet coated with Al2O3 on one side was obtained. 【0182】 Battery assembly 【0183】 Battery assembly was performed in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two stainless steel pistons with a diameter of 8 mm 【0184】 Two electrode cells were assembled as follows. 【0185】 A cathode composite (NMC622 / Li3InCl6 / VGCF) of 16 - 18 mg / cm 2 was spread on the Al2O3 - coated surface of a Li6PS5Cl solid electrolyte pellet. Next, a mixture of Li0.5In and Li6PS5Cl (weight ratio 60:40) was added as a counter - electrode on the uncoated side of the Li6PS5Cl solid electrolyte pellet. 【0186】 Finally, the entire stack was further densified at 4 t / cm 2 for 15 minutes. After compression, a pressure of 1 t / cm 2 was applied to the fully assembled cell for electrochemical research. 【0187】 All assembly procedures were carried out under an argon atmosphere ([O2]<1 ppm, [H2O]<1 ppm) in a glove box. 【0188】 Comparative Example 3 【0189】 A solid sulfide electrolyte, a solid halide electrolyte, and a cathode composite were produced as described above for Comparative Example 1. 【0190】 Atomic layer deposition 【0191】 A nanometer - thick Al2O3 film was grown in a Picosun R200 advanced ALD reactor under an argon pressure of around 2 mbar. Argon was used as the carrier gas and purge gas. 【0192】 Trimethylaluminum (TMA) and ozone (O3) precursors were used as aluminum and oxygen sources, respectively. The TMA precursor was purchased from STREM Chemical (purity 98%), and the O3 precursor was synthesized using a USA Inc. ozone AC - series generator model AC - Bench 2025 with a mixed gas of O2 99.5% and N2 0.5%. 【0193】 The temperature of the ALD reactor was set at 150 °C, and the growth rate was 1.4 Å per cycle. In this way, 71 cycles were performed to obtain a buffer layer with a thickness of 10 nm. 【0194】 TMA and O3 were alternately pulse-injected into the chamber with pulse times of 0.3 s and 0.5 s, respectively, separated by a 5-s argon purge. 【0195】 A Li6PS5Cl solid electrolyte pellet coated with a 10-nm-thick Al2O3 buffer layer on one side was obtained. 【0196】 Battery assembly 【0197】 Battery assembly was carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two stainless steel pistons with a diameter of 8 mm. 【0198】 Two electrode cells were assembled as follows. 【0199】 16 - 18 mg / cm 2 of the cathode composite (NMC622 / Li3InCl6 / VGCF) was spread on the Al2O3-coated surface of the Li6PS5Cl solid electrolyte pellet, and then a mixture of Li0.5In and Li6PS5Cl (weight ratio 60:40) was added as a counter electrode to the uncoated side of the Li6PS5Cl solid electrolyte pellet. 【0200】 Finally, the entire stack was further densified at 4 t / cm 2 for 15 minutes. After compression, a pressure of 1 t / cm 2 was applied to the fully assembled cell for electrochemical research. 【0201】 All assembly procedures were carried out under an argon atmosphere ([O2] < 1 ppm, [H2O] < 1 ppm) in a glove box. 【0202】 Electrochemical tests 【0203】 For all examples, the experiments were carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two stainless steel pistons with a diameter of 8 mm. 【0204】 All electrochemical cycle procedures were carried out at room temperature under an argon atmosphere ([O2]<1 ppm, [H2O]<1 ppm) in a glove box unless otherwise specified. 【0205】 Conductivity measurement 【0206】 The ionic conductivity was measured by electrochemical impedance spectroscopy (EIS) using an MTZ impedance analyzer (BioLogic) with an excitation amplitude of 50 mV at 15 points per decade in the frequency range of 7 MHz to 1 Hz at OCV. 【0207】 The results of the 1 nm thick buffer layer of Li3PO4 are shown in Figure 2, indicating that the presence of the buffer layer enables lithium ion conduction while providing a slight resistance. 【0208】 Figure 6 shows that buffer layers with a thickness of 10 nm of Li3PO4 (Figure 6a) and Al2O3 (Figure 6b) result in resistances of more than 300 kΩ and more than 150 kΩ, respectively. 【0209】 Therefore, buffer layers with a thickness of at least 10 nm reduce ionic conductivity, and as a result, satisfactory ASSBs cannot be obtained. 【0210】 Galvanostatic cycle 【0211】 The test study of the galvanostatic cycle was carried out at room temperature at C / 20 (C corresponds to 1 mole of lithium per mole of active material per hour). All electrochemical measurements were performed using a VMP3 potentiostat / galvanostat (BioLogic) controlled by EC-Lab software. 【0212】 Figure 3 shows the cycle performance of the cell stack of Example 1 according to the present invention at 2.1 - 3.6 / 3.7 / 3.8 V vs. LiIn / In (2.7 - 4.2 / 4.3 / 4.4 V vs. Li / Li). The first cycle curves are shown in Figs. 3(a) and 3(c), and the capacity retention rates are shown in Figs. 3(b) and 3(d), for cells including buffer layers with thicknesses of 2 nm and 1 nm respectively. These figures show a low irreversible capacity and low polarization after the initial cycle, as well as a stable capacity retention rate over cycles for buffer layers of both thicknesses. + / Li). 【0213】 Figure 5 shows the cycle performance of the cell stack of Example 2 according to the present invention at 2.1 - 3.6 V vs. LiIn / In. The first cycle curve is shown in Fig. 5a, and the capacity retention rate over 60 cycles is shown in Fig. 5b. These figures also show a low irreversible capacity and low polarization after the initial cycle, as well as a stable capacity retention rate over cycles for cells including two buffer layers. 【0214】 Figure 4 shows the cycle performance of a cell stack according to Comparative Example 1, i.e., a cell stack without a buffer layer, under the same conditions as the examples according to the present invention. The first cycle curve is shown in Fig. 4(a), and the capacity retention rate is shown in Fig. 4(b). Both are under an argon atmosphere and inside a hermetic cell under an ambient atmosphere. These figures show that in the absence of a buffer layer, the cell shows a significant capacity decrease over cycles. This decrease is related to the interfacial barrier caused by the absence of the buffer layer. It is shown that this decrease is not due to the cell setup, because it is possible to test the cycle performance of the material under an ambient atmosphere while providing airtightness. 【0215】 FIG. 7 shows the cycle performance of cell stacks according to Comparative Examples 2 and 3, i.e., cell stacks having a 10 nm thick buffer layer of Li3PO4 (FIG. 7a) or Al2O3 (FIG. 7b), under the same conditions as the examples according to the present invention. These figures show that when a current is applied to the cell with a buffer layer having a thickness of at least 10 nm, the measured potential is the open circuit voltage (OCV). As observed in FIG. 6, this is due to the very low conductivity of the solid electrolyte having a 10 nm thick buffer layer. 【0216】 These results show that the assembly according to the present invention can be assembled into an ASSB according to the present invention, obtaining satisfactory ionic conductivity while alleviating the influence of the instability between different components of the ASSB, i.e., enabling the maintenance of a stable capacity over the service life of the assembly or the ASSB containing it.

Claims

[Claim 1] All-solid-state batteries, including the following: - Anode containing an anode active material and a first solid electrolyte, - Cathode composite containing a cathode active material and a second solid electrolyte, - A solid electrolyte comprising a solid electrolyte material selected from the group consisting of the first solid electrolyte and the second solid electrolyte, - At least one buffer layer, particularly one or two buffer layers, in contact with the surface of the solid electrolyte material. It has, When the solid electrolyte material is the first solid electrolyte, one buffer layer is located at the interface of the electrolyte with the cathode composite. When the solid electrolyte material is the second solid electrolyte, one buffer layer is located at the interface of the electrolyte with the anode. The first electrolyte is selected from sulfide solid electrolytes and lithium oxide solid electrolytes. The second electrolyte is a halogenated solid electrolyte. The buffer layer has a thickness of 0.5 to less than 10 nm. All-solid-state battery. [Claim 2] An assembly, which includes the following: - A solid electrolyte comprising a solid electrolyte material selected from the group consisting of halide solid electrolytes, sulfide solid electrolytes, and lithium oxide solid electrolytes, and - At least one buffer layer, particularly one or two buffer layers, in contact with the surface of the solid electrolyte material. It has, The buffer layer has a thickness in the range of 0.5 to less than 10 nm. assembly. [Claim 3] An assembly, which includes the following: - An anode comprising an anode active material and a solid electrolyte selected from sulfide solid electrolytes and lithium oxide solid electrolytes, - A buffer layer in contact with the surface of the anode composite, It has, The buffer layer has a thickness in the range of 0.5 to less than 10 nm. assembly. [Claim 4] An assembly, which includes the following: - A cathode composite comprising a cathode active material and a halogen solid electrolyte, and - A buffer layer in contact with the surface of the cathode composite, It has, The buffer layer has a thickness in the range of 0.5 to less than 10 nm. assembly. [Claim 5] The anode active material is as follows: - Oxides, - Nitride, - Carbon, such as natural graphite, coke, activated carbon, carbon fibers, spheroidal carbon, artificial graphite, and amorphous carbon, - Metals, such as silicon, tin, sodium, or lithium, their compounds and alloys, Selected from, In particular, the anode active material is silicon, tin, lithium, their compounds and alloys, for example Li ｘ In ｙ Selected from, where x is in the range of 0 to 1 and y is in the range of 0 to 1, preferably the anode active material is Li ０．５ In, the all-solid-state battery according to claim 1, or the assembly according to claim 3. [Claim 6] The anode is one of the following: - 50 to 70% by weight, preferably 60% by weight of Li ０．５ In, and - 30 to 50% by weight, preferably 40% by weight, a sulfide solid electrolyte, A solid-state battery according to claim 1, or an assembly according to claim 3, comprising: [Claim 7] The cathode active material is selected from transition metal fluorides, polyanionic materials, fluorinated polyanionic materials, transition metal sulfides, transition metal oxyfluorides, transition metal oxysulfides, transition metal oxynitrides, and lithium-containing transition metal oxides, doped or undoped, coated or uncoated, and in particular, the cathode active material is a transition metal oxide, such as lithium cobaltate, lithium nickel-cobalt-aluminate, or lithium nickel-manganese-cobaltate, preferably of the formula LiNi ０．６ Mn ０．２ Co ０．２ O ２ The all-solid-state battery according to claim 1, or the assembly according to claim 4. [Claim 8] The cathode complex is as follows: - 55 to 75% by weight, particularly 60 to 70% by weight, preferably 66.7% by weight, cathode active material, - 20 to 40% by weight, particularly 25 to 30% by weight, preferably 28.6% by weight, a halogenated solid electrolyte, and optionally, - 1 to 10% by weight, particularly 2 to 7% by weight, preferably 4.8% by weight, an electronically conductive carbon compound, A solid-state battery according to claim 1, or an assembly according to claim 4, comprising: [Claim 9] All-solid-state battery according to claim 1, or assembly according to claim 3 or 4, wherein at least one electrode comprises an electron conductor compound selected from natural or artificial graphite, graphene, carbon nanotubes, acetylene black, Ketjenblack, activated carbon, carbon fluoride, metal powder, conductive whiskers, conductive metal oxides, conductive polymers, metal fibers, or carbon fibers, preferably the electron conductor being vapor-grown carbon fiber. [Claim 10] The aforementioned halogen solid electrolyte is of the following formula: [Math 1] Here, -3 ≤ z ≤ 3, 2 ≤ k < 6, and 0 ≤ f ≤ 1; - M contains alkali metal elements, and especially lithium; - Me includes divalent, trivalent, tetravalent, pentavalent, or hexavalent metallic elements, or any combination thereof, in particular Me includes the following: i. Alkaline earth metals, e.g., Ba, Mg, Ca, Sr, ii. Rare earth elements, such as Y, Sc, Ce, Gd, Er, La, Yb, and combinations thereof, iii. 3d transition metals, e.g., Zn, Cu, V, iv. Elements selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, Ga, and, v. Any combination of those, Selected from, - X is a halogen, and is particularly selected from Cl, Br, I and any combination thereof. Preferably, the halide solid electrolyte is Li ３ InCl ６ is. A solid-state battery according to claim 1, or an assembly according to claim 2 or 4. [Claim 11] The sulfide solid electrolyte is thiophosphate and Li ７－ｘ PS ６－ｘ X ｘ Selected from the group consisting of argyrodites, where 0 ≤ x ≤ 2, and X is a halide, particularly selected from Cl, Br, and I, preferably the first solid electrolyte is selected from argyrodites, and more preferably Li ６ PS ５ A solid-state battery according to claim 1, or an assembly according to any one of claims 2 to 4, wherein the material is Cl. [Claim 12] The lithium oxide solid electrolyte is NASICON, for example, LiTi ２ (PO ４ ) ３ etc.; perovskites, e.g., (LaLi)TiO ３ etc; LISICON, for example Li １４ ZnGe ４ O １６ Li ４ SiO ４ , or LiGeO ４ etc; garnet, for example Li ７ La ３ Zr ２ O １２ Selected from the group consisting of the above, in particular, the lithium oxide solid electrolyte is garnet, preferably Li ７ La ３ Zr ２ O １２ The all-solid-state battery according to claim 1, or the assembly according to any one of claims 2 to 4. [Claim 13] The all-solid-state battery according to claim 1, or the assembly according to any one of claims 2 to 4, wherein the buffer layer has a thickness in the range of 0.75 to 5 nm, preferably 1 to 2 nm. [Claim 14] The buffer layer is lithium phosphate, for example Li ３ PO ４ For example, lithium nitride phosphate; lithium nitride; NASICON, e.g., LiTi ２ (PO ４ ) ３ etc.; perovskites, e.g., (LaLi)TiO ３ etc; LISICON, for example Li １４ ZnGe ４ O １６ Li ４ SiO ４ , or LiGeO ４ etc; garnet, for example Li ７ La ３ Zr ２ O １２ etc; and Al ２ O ３ It includes a buffering material selected from, and more particularly consists of, the buffering layer is Li ３ PO ４ or Al ２ O ３ Includes, and especially Li ３ PO ４ or Al ２ O ３ Consists of; preferably, the buffer layer is Li ３ PO ４ Includes, and especially Li ３ PO ４ A solid-state battery according to claim 1, or an assembly according to any one of claims 2 to 4. [Claim 15] A method for manufacturing an all-solid-state battery according to claim 1, or an assembly according to any one of claims 2 to 4, comprising depositing the buffer layer on at least one substrate selected from the solid electrolyte, the anode composite, and the cathode composite by a vapor deposition-based method, for example by physical vapor deposition, chemical vapor deposition, or atomic layer deposition, preferably by atomic layer deposition. [Claim 16] The method according to claim 15, wherein the buffer layer is deposited on a powder substrate or a densified substrate. [Claim 17] The buffer layer is deposited by atomic layer deposition, and the reactor for atomic layer deposition is set to the following temperature: A range of 85°C to 185°C, particularly a range of 100°C to 170°C, preferably 150°C, or A range of 200°C to 400°C, particularly a range of 250°C to 350°C, preferably 300°C. The method according to claim 15, which is set to [a certain value].

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