Methods for producing solid-state batteries

Abstract

The present invention relates to an all-solid-state battery (ASSB) element or a method for producing an ASSB containing a halide solid electrolyte, the method comprising an oxidation step and a degassing step. Furthermore, the present invention relates to an ASSB element and an ASSB obtained by the production method according to the present invention.

Description

[Technical Field]

[0001] The present invention is in the field of all-solid-state rechargeable batteries (ASSBs), and in particular relates to methods for producing ASSBs containing halide solid electrolytes. [Background technology]

[0002] ASSBs are of particular interest as replacements for conventional Li-Ion batteries because they have relatively fewer safety concerns and relatively high capacity or energy density.

[0003] To achieve ASSB, a solid electrolyte is used to replace the liquid electrolyte in Li-Ion batteries, and ASSB uses a Li metal anode and high-energy NMC cathode particles, which are embedded in the solid electrolyte.

[0004] Such solid electrolytes are selected from, for example, lithium thiophosphate (β-Li3PS4, LPS), argyrodite (Li6PS5Cl), such as those described by HJ Deiseroth et al. in "Li6PS5X: A class of lithium-rich crystalline solids with very high Li+ mobility" (Angew. Chem. Int. Ed., 47 (2008), pp. 755-758), and halides, such as Li3InCl6, such as those described in X. Li et al. in "High-voltage compatible air-stable Li3InCl6 electrolytes for solid-state batteries" (Energy Environ. Sci., 2019, 12, pp. 2665-267); Schmidt, MO et al. in "Zur Kristallstruktur von Li3InCl6." (Zeitschrift fur Anorg. und Allg. 1999, 625(4), 539-540; and G. Meyer et al., "Handbook of the Physics and Chemistry of Rare Earths" (V. 28, Chapter 177, 2000 Elsevier Sci.).

[0005] However, the main drawback of these compounds is their chemical and electrochemical interactions with the electrode materials.

[0006] Halide solid electrolytes have attracted particular attention because they exhibit good ionic conductivity (greater than 2 mS / cm) and superior compressibility (deformability) compared to other solid inorganic electrolytes. Among these compounds, polyhalide solid electrolytes containing at least two halide ions, such as Cl and Br, have attracted particular attention because the heavier halogens, such as Br and I, provide high electrolyte conductivity, while the lighter halogens, such as Cl and F, have relatively high electrochemical stability at high potentials.

[0007] However, the present inventors have surprisingly discovered that when halide solid electrolytes, particularly polyhalide solid electrolytes, are subjected to high potentials, various substances are formed from the decomposition of the electrolyte, which have been identified as halogenated species, such as Br2 and I2.

[0008] These various substances are highly oxidizing and can result in reactions with various elements of the ASSB, such as its electrode active material or current collector, which will reduce the capacity or service life of the battery. Furthermore, when these various substances become gaseous, they can cause dangerous overpressures within the battery cell. Summary of the Invention [Problem to be solved by the invention]

[0009] As identified by the inventors, the in situ formation of various materials can pose several problems.

[0010] Therefore, the present invention solves the above identified technical problems by: - Improving battery safety; - Improve the capacity and lifespan of the battery; - Enabling the use of halide solid electrolytes, especially polyhalide solid electrolytes, in ASSBs.

[0011] The invention is further easily implemented in a method for producing ASSB elements or of the ASSB itself, especially on an industrial scale.

[0012] A production method is understood to refer to any method designed to "produce" an ASSB element or the ASSB itself, i.e., so that it can be used and / or function properly after undergoing the method according to the present invention. [Means for solving the problem]

[0013] Thus, in a first aspect, the present invention relates to a method for producing an all-solid-state battery element comprising a halide solid electrolyte, characterized in that the method comprises the following steps: (a) an oxidation process for the all-solid-state battery element; and (b) Degassing process.

[0014] The oxidation step according to the invention can be carried out by applying a voltage or, advantageously in the case of an all-solid-state battery element, by treatment with an oxidizing gas, such as Cl2.

[0015] In a second aspect of the invention, the invention also relates to a method for producing an all-solid-state battery having, in sequence, an anode, at least one electrolyte layer, and a cathode, wherein a halide solid electrolyte is included in at least one of the one or more electrolyte layers and / or in the cathode, the method comprising the steps of: (a) applying a voltage U to an all-solid-state battery, U=E+E ref where: E ref is the potential difference between the anode and the lithium metal anode, E is a voltage in the range of 3.0 V to 5.5 V, particularly in the range of 3.5 V to 4.0 V, and preferably in the range of 4.0 V to 4.5 V; (b) A degassing step as defined herein.

[0016] The present invention also relates to both an all-solid-state battery element and an all-solid-state battery comprising a halide solid electrolyte, obtainable by the method according to the invention.

[0017] The degassing step implemented in the method according to the invention makes it possible to remove from the battery cell various substances that are formed in situ under normal conditions of use. [Effects of the Invention]

[0018] First, by removing the various materials, the internal pressure of the battery cell is reduced, thereby preventing any leakage.

[0019] Furthermore, the various materials mentioned above are strong oxidizing agents that can react with several components of the ASSB, such as the electrode active material, e.g., lithium nickel manganese cobalt oxide in the cathode, or the current collector, etc. The present invention makes it possible to prevent such reactions by removing the various materials, which in turn makes it possible to prevent any associated degradation in the capacity and / or life of the ASSB.

[0020] Furthermore, polyhalide solid electrolytes are of particular interest because they can combine the high conductivity of heavier halides with the stability of lighter halides through a passivation mechanism. However, this passivation leads to the formation of various species, which is a major drawback of polyhalide solid electrolytes. Therefore, the present invention allows these materials to be used without adversely affecting the performance of ASSBs.

[0021] Finally, the present invention is easily implemented into battery production lines. Indeed, although the need for degassing has not yet been identified for ASSBs, degassing processes are conventionally implemented for lithium-ion batteries to remove gases formed during the battery formation stage.

[0022] As reported in Deng, Z., Joule, 4, 2020, 2017-2029, in lithium-ion batteries, the reduction of the liquid electrolyte at the negative electrode leads to the formation of a solid electrolyte interface (SEI) and hydrocarbon gases. In industry, these gases are removed during the first cycle of the battery.

[0023] However, to the best of the inventors' knowledge, decomposition of the electrolyte into different substances is not anticipated in ASSBs, and it has been conventionally recognized that a degassing step, also known as a degassing step, is not necessary (see, for example, Fraunhofer ISI, Solid-state battery roadmap 2035+, April 2022).

[0024] Strauss, F., ACS Appl. Mater. Interfaces 2020, 12, 20462-20468, reports several cases of gas formation in ASSBs, which has also been observed in Li-ion batteries. However, this gas formation is due to the degradation of the cathode active material. However, this invention does not concern the cathode active material, since it is only concerned with the various substances formed by the controlled electrochemical generation of the halide solid electrolyte, which is carried out before any actual cycling. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a graphical representation of the cyclic voltammetry performed in the following examples on (a) an untreated cell corresponding to Comparative Example 1, and (b) a degassed cell corresponding to Example 2 according to the invention, where the x-axis represents the potential applied to the cell and the y-axis represents the intensity of the measured current. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention can be implemented in any ASSB element containing a halide solid electrolyte. ASSB element can refer to any element found in an ASSB or from which an ASSB can be derived. Preferably, the present invention is suitable for the electrolyte layer, the cathode electrolyte, i.e., the mixture of cathode active material and electrolyte, or the electrolyte material itself. The electrolyte material can be in powder form, paste form containing the powder, or slurry form.

[0027] Thus, the ASSB element or ASSB obtained by the method according to the invention may comprise a halide solid electrolyte, as will be explained in detail herein below.

[0028] In an ASSB according to the present invention or an ASSB implemented in a method according to the present invention, a halide solid electrolyte can be included in the cathode and / or in the electrolyte layer.

[0029] Halide solid electrolyte

[0030] The halide solid electrolyte can be represented by the following chemical formula: M 3-z (Me k+ ) f X 3-z+k*f where -3≦z≦3, k is the valence of Me, 2≦k<6, 0≦f≦1; M comprises an alkali metal element, in particular Li; Me includes a metal other than an alkali metal, X is a halogen.

[0031] In certain embodiments, f is different from zero.

[0032] In certain embodiments, Me includes multiple metal elements, and k can be the average value of the sum of the valences of the individual metal elements. For example, if Me includes equimolar amounts of trivalent and tetravalent elements, k = (3 + 4) / 2 = 3.5. In particular, k can be 2, 3, 4, or 5.

[0033] It is understood that atomic vacancies may exist within the unit cell of the halide solid electrolyte. In this case, the atomic vacancies are represented by 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 is the number of vacant atomic positions. In certain embodiments, y is equal to f * It can be (k-1).

[0034] In certain embodiments, M can include Li, Na, K, Rb, Cs, or any combination thereof. For example, M can include at least one of Li and Na, or a combination thereof. In further aspects, 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 Na and at least one of Cs and Rb. In another example, M can consist of at least one of Na and Cs.

[0035] In certain embodiments, Me may include elements selected from alkaline earth elements; rare earth elements; 3d transition metals; Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, Ga, and any combination thereof. For example, Me may include alkaline earth metals including Ba, Mg, Ca, Sr, or any combination thereof. In another example, Me may include a rare earth element, and more particularly, 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, and more particularly, a 3d transition metal selected from Zn, Cu, V, and any combination thereof. In yet another example, Me can include an element selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, Ga, and any combination thereof.

[0036] In certain embodiments, X may comprise a halogen, particularly a halogen selected from Cl, Br, I, and any combination thereof. By way of example, X may comprise at least one of Cl and Br. Preferably, X may consist of Cl, Br, or any combination thereof. In particularly preferred embodiments, X consists of Cl and Br.

[0037] Thus, an all-solid-state battery element or battery according to the present invention, or an all-solid-state battery element or battery implemented in a method according to the present invention, may comprise a halide solid electrolyte of the following formula: M 3-z (Me k+ ) f X 3-z+k*f where -3≦z≦3, 2≦k<6, 0≦f≦1; M comprises an alkali metal element, in particular Li; Me comprises a divalent, trivalent, tetravalent, pentavalent or hexavalent metallic element or any combination thereof, in particular Me is selected from: 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., and iv. an element selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, and Ga; v. any combination thereof; X is a halogen, in particular selected from Cl, Br, I and any combination thereof; Preferably, the halide solid electrolyte is selected from Li3InCl6 and Li3Y(Cl,Br)6.

[0038] As used herein, for example in LiY(Cl,Br) it is understood that (Cl,Br) means that any combination of Cl and Br may be present in the compound, and the sum of the stoichiometric coefficients of Cl and Br is equal to 6.

[0039] In certain embodiments, the halide solid electrolyte is Li 3-z Me k+ X 3-z+k When z is not 0, the complex metal halide may be non-stoichiometric. When z is 0, the complex metal halide may be stoichiometric. For example, -0.95≦z≦0.95. In another example, Me may be Y, Gd, Yb, In, Sc, Zn, Mg, Ca, Ba, Sn, or a combination thereof, and X may be Cl, Br, or a combination thereof.

[0040] In certain embodiments, the halide solid electrolyte is a polyhalide solid electrolyte, particularly comprising at least one of Cl and F and at least one of Br and I; preferably, the halide solid electrolyte comprises at least Cl and Br.

[0041] As used herein, "one or more polyhalide solid electrolytes" is understood to refer to one or more halide solid electrolytes that contain at least two halide ions.

[0042] In certain embodiments, the solid halide electrolyte may be represented by Li3MeBr6. In another specific embodiment, the solid halide electrolyte may be represented by Li3MeCl6. In a preferred embodiment, the solid halide electrolyte may be represented by Li3Me(Cl,Br)6. In these embodiments, Me may consist of at least one of the above metal elements and have a valence of 3. Me may include at least one of the above metal elements, where the average valence of the at least one metal element is 3.

[0043] In another specific embodiment, the solid halide electrolyte can be composed of Li, Y, In, and at least one of Cl and Br. For example, the solid halide electrolyte can be composed of Li, Y, In, and Cl. In another example, the solid halide electrolyte can be composed of Li, Y, In, and Br. In a preferred example, the solid halide electrolyte can be composed of Li, Y, In, Cl, and Br. In a specific example, the solid halide electrolyte can be composed of Li 3x (Y,In) 1-x Cl3, Li 3x (Y,In) 1-x Br3 or Li 3x (Y,In) 1-x (Cl,Br)3, where 0 <x≦0.5である。

[0044] In another specific embodiment, the solid halide electrolyte can be comprised of Li, Y, and at least one of Cl and Br. For example, the solid halide electrolyte can be comprised of Li, Y, and Cl. In another example, the solid halide electrolyte can be comprised of Li, Y, and Br. In yet another example, the solid halide electrolyte can be comprised of Li, Y, Cl, and Br. In a particular example, the solid halide electrolyte can be comprised of Li 3x Y 1-x Cl3, Li 3xY 1-x Br3 or Li 3x Y 1-x (Cl,Br)3, where 0 <x≦0.5である。

[0045] In another specific embodiment, the solid halide electrolyte can be comprised of Li, Gd, and at least one of Cl and Br. For example, the solid halide electrolyte can be comprised of Li, Gd, and Cl. In another example, the solid halide electrolyte can be comprised of Li, Gd, and Br. In yet another example, the solid halide electrolyte can be comprised of Li, Gd, Cl, and Br. In a particular example, the solid halide electrolyte can be comprised of Li 3x Gd 1-x Cl3, Li 3x Gd 1-x Br3 or Li 3x Gd 1-x It may be represented as (Cl,Br)3, where 0.01≦x<1.

[0046] In another specific embodiment, the solid halide electrolyte can be comprised of Li, In, and at least one of Cl and Br. For example, the solid halide electrolyte can be comprised of Li, In, and Cl. In another example, the solid halide electrolyte can be comprised of Li, In, and Br. In yet another example, the solid halide electrolyte can be comprised of Li, In, Cl, and Br. In a particular example, the solid halide electrolyte can be comprised of Li 3x In 1-x Cl3, Li 3x In 1-x Br3 or Li 3x In 1-x It may be represented as (Cl,Br)3, where 0≦x<0.5.

[0047] Solid halide electrolytes include Li3InCl6, Li3InBr6, Li3In(Cl,Br)6, Li3YCl6, Li3YBr6, Li3Y(Cl,Br)6, Li2.7Y0.7Zr0.3Cl6, Li2.8Y0.8Sn0.2Cl6, Li3.2Y0.8Zn0.2Cl6, Li3.2Y0.8Mg0.2Cl6, and Li3Y 1 / 3 Zr1 / 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, Li2. 95 Na0. 05 YBr6, Li2. 95 K0. 05 YBr6, Li2. 95 Cs0. 05 It may be selected from YBr6, Li3Y0.7Gd0.3Br6, Li3Y0.8Yb0.2Br6, Li3Y0.9La0.1Br6, Li2.9Y0.9Ce0.1Br6, or Li3In0.5Y0.5Cl6.

[0048] Solid halide electrolytes include Li3InCl6, Li3InBr6, Li3In(Cl,Br)6, Li3YCl6, Li3YBr6, Li3Y(Cl,Br)6, Li2.7Y0.7Zr0.3Cl6, Li2.8Y0.8Sn0.2Cl6, Li3.2Y0.8Zn0.2Cl6, Li3.2Y0.8Mg0.2Cl6, and 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, Li2. 95 Na0. 05 YBr6, Li2. 95 K0. 05 YBr6, Li2. 95 Cs0. 05 YBr6, Li3Y0.7Gd0.3Br6, Li3Y0.8Yb0.2Br6, Li3Y0.9La0.1Br6, Li2.9Y0.9Ce0.1Br6, or Li3In0.5Y0.5Cl6, Li3Y0. 75 In0. 25 Cl4Br2, Li3Y0.8In0.2Cl4Br2, Li3Y0. 85 In0. 15Cl4Br2, Li3Y0.9In0.1Cl4Br2, Li3Y0. 85 In0. 15 Cl3.5Br2.5, and Li3Y0. 985 In0. 015 Cl4Br2.

[0049] anode

[0050] In an ASSB, 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.

[0051] Carbon, oxides or nitrides of the metals in the anode active material can be used.

[0052] 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, silicides, tin compounds, lithium, and lithium alloys.

[0053] Examples of carbon suitable for use as the anode active material include natural graphite, coke, engineered carbon, carbon fiber, spherical carbon, artificial graphite, and amorphous carbon.

[0054] Thus, in an all-solid-state battery according to the invention or an all-solid-state battery implemented in a method according to the invention, the anode active material may be: - oxides, - nitrides, Carbon, such as natural graphite, coke, engineered carbon, carbon fiber, spherical carbon, artificial graphite, and amorphous carbon; metals, such as silicon, tin, sodium or lithium, their compounds and their alloys, may be selected from In particular, the anode active material may be silicon, tin, lithium, compounds thereof, and alloys thereof, such as Lix In y wherein x is in the range of 0 to 1 and y is in the range of 0 to 1, and preferably the anode active material is selected from Li 0.5 In or lithium.

[0055] The thickness of the anode in an ASSB according to the present invention or an ASSB implemented by a method according to the present invention may be in the range of 10 μm to 500 μm.

[0056] At least one of the anode and cathode may comprise an electronic conductor compound selected from natural or synthetic graphite, graphene, carbon nanotubes, acetylene black, ketogen black, activated carbon, carbon fluoride, metal powder, conductive whiskers, conductive metal oxides, conductive polymers, metal fibers, or carbon fibers. Preferably, the electronic conductor is vapor-deposited carbon fiber.

[0057] Cathode

[0058] In an all-solid-state battery according to the present invention or implemented with a method according to the present invention, the cathode composite can include a cathode active material and a halide solid electrolyte, as described above.

[0059] 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.

[0060] The cathode active material may be a transition metal fluoride, a polyanionic material, a fluorinated polyanionic material, a transition metal sulfide, a transition metal oxyfluoride, a transition metal oxysulfide, a transition metal oxynitride, or a lithium-containing transition metal oxide, doped or undoped, coated or uncoated. In particular, the cathode active material may be a transition metal oxide, such as lithium cobalt oxide, lithium nickel cobalt aluminum oxide, or lithium nickel manganese cobalt oxide. Suitable transition metal oxides for use as the cathode active material include, for example, LiNi0.6 Mn 0.2 Co 0.2 O2, Li(NiCoAl)O2, and LiCoO2. Preferably, the cathode active material is LiNi 0.6 Mn 0.2 Co 0.2 O2 or LiNi 0.8 Mn 0.1 Co 0.1 It is a transition metal oxide of the formula:

[0061] The cathode active material may be present in the ASSB of the present invention in the form of particles. The average diameter of the anode active material particles may range from 0.1 μm to 100 μm. Preferably, the average diameter of the anode active material particles is larger than the average diameter of the solid electrolyte particles.

[0062] The thickness of the anode in an ASSB according to the present invention or an ASSB implemented by a method according to the present invention may range from 10 μm to 500 μm.

[0063] At least one of the anode and cathode comprises an electronic conductor compound selected from natural or artificial graphite, graphene, carbon nanotubes, acetylene black, ketogen black, activated carbon, carbon fluoride, metal powder, conductive whiskers, conductive metal oxides, conductive polymers, metal fibers, or carbon fibers; preferably, the electronic conductor is vapor-deposited carbon fiber.

[0064] Thus, in the all-solid-state battery according to the invention or in the all-solid-state battery implemented with the method according to the invention, the cathode comprises a cathode active material 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 not, coated or not, and in particular the cathode active material is a transition metal oxide, such as lithium cobalt oxide, lithium nickel cobalt aluminum oxide, or lithium nickel manganese cobalt oxide, preferably of the formula LiNi0.6 Mn 0.2 Co 0.2 O2 or LiNi 0.8 Mn 0.1 Co 0.1 It is of the type.

[0065] Generation method

[0066] An all-solid-state battery element or battery according to the present invention, or an all-solid-state battery element or battery implemented in a production method according to the present invention, is first obtained through a process well known to those skilled in the art, for obtaining the element or ASSB containing the desired material.

[0067] The present invention resides in the addition of a degassing step to the methods known in the art. As used herein in the plural, "degassing steps" is meant to include the oxidation step, particularly in the case of ASSB, the step of applying a voltage, and the actual degassing step.

[0068] The degassing step is intended to remove any substances formed by electrochemical reactions within the ASSB, and in particular, to remove substances formed by electrochemical reactions of the halide solid electrolyte, preferably the polyhalide solid electrolyte, contained within the anode and / or one or more electrolyte layers of the ASSB.

[0069] As illustrated by the description of halide solid electrolytes suitable for the present invention, the various materials formed can be halide species, namely F2, Cl2, Br2, and I2.

[0070] In a preferred embodiment of the present invention, the degassing step involves removing halogenated species, in particular Cl2, Br2 and / or I2, preferably Br2 and / or I2.

[0071] "Removing" is understood to mean removing the various substances from the ASSB element or from contact with the ASSB, for example, in the case of an ASSB, removing the various substances from the housing.

[0072] The oxidation step can be carried out for a time period ranging from 10 minutes to 10 hours, in particular from 30 minutes to 5 hours, preferably from 45 minutes to 3 hours.

[0073] The oxidation step may involve treating the ASSB element as defined above with an oxidizing gas, such as Cl2. Such treatment may be carried out in a furnace, preferably a tubular furnace, initially filled with an inert gas, such as nitrogen, argon, or a mixture thereof; then, Cl2 gas may be introduced, for example, at a pressure in the range of 0.1 to 10 mbar, and the furnace may be heated to a temperature in the range of 100 to 300°C for a time corresponding to the time of the oxidation step described above. When the gas flow is stopped, the furnace may be heated for 10 to 300°C. -5 ~10 -3 The air may be evacuated to a pressure range of 0.1 to 1.5 mm for a time range of 2 to 30 minutes, and the ASSB element may then be placed in an inert atmosphere, such as an inert atmosphere consisting essentially of nitrogen, argon, or a mixture thereof, for example, in a glove box.

[0074] The above voltages have the following relationship: U=E+E ref is defined by, where: E ref is the potential difference between the anode of the ASSB and the lithium metal anode, E is a voltage in the range of 3.0V to 5.5V, particularly in the range of 3.5V to 4.0V, and preferably in the range of 4.0V to 4.5V.

[0075] In a particular embodiment of the invention, the voltage U is applied for a time in the range of 10 minutes to 10 hours, in particular in the range of 30 minutes to 5 hours, preferably in the range of 45 minutes to 3 hours.

[0076] When applied to an ASSB device, the degassing step may comprise, and preferably may consist of, placing the all-solid-state battery device under a dynamic vacuum.

[0077] When applied to an ASSB, the degassing step may include, and preferably may consist of, opening the battery cell and placing the resulting open cell under a dynamic vacuum.

[0078] In either case, the dynamic vacuum is 10 -3 mbar~10 -1 mbar range, especially 5.10 -3 mbar~5.10 -2 mbar range, preferably 7.10 -3 mbar~2.10 -2 Pressures in the mbar range can be maintained.

[0079] In a particular embodiment of the invention, the degassing step is carried out for a time in the range of 1 minute to 10 hours, in particular in the range of 5 minutes to 5 hours, preferably in the range of 10 minutes to 3 hours.

[0080] In a particular embodiment of the present invention, the degassing step may be carried out at a temperature in the range of 15°C to 70°C, in particular in the range of 20°C to 50°C, preferably in the range of 25°C to 40°C.

[0081] In a particular embodiment of the invention, after the degassing step the cell is closed and pressurized to a pressure of preferably 250 kg / cm 2 ~3000kg / cm 2 Pressures in the range of 500 kg / cm 2 ~1500kg / cm 2 The mixture is pressed under a pressure ranging from 0.1 to 1.0.

[0082] The cell may be closed and pressed under an inert atmosphere, preferably under argon. [Example]

[0083] The method of the present invention will be further illustrated through the following examples.

[0084] Comparative Example 1

[0085] The cell assembly was carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two 8 mm diameter stainless steel pistons.

[0086] The assembly work was carried out under an argon atmosphere in a glove box ([O2]<1 ppm, [H2O]<1 ppm).

[0087] A two electrode cell was assembled as follows.

[0088] 80 mg of Li3YCl4Br2 is spread evenly and subjected to 250 kg / cm 2 It was cold pressed.

[0089] 10 mg / cm 2 The cathode composite (90:10 ratio Li3YCl4Br2 / Carbon Super C65) was spread on the cathode side surface of the pressed Li3YCl4Br2. The stack was then pressurized to 1100 kg / cm 2 The mixture was further densified at RT for 15 min.

[0090] Next, Li 0.5 A lithium indium complex, with the formula In, was added as a counter electrode on the anode side, opposite the Li3YCl4Br2 pellet.

[0091] Finally, the whole is 4t / cm 2 After compression, the powder was further densified at 1100 kg / cm for 15 minutes. 2 A pressure of 0.05 MPa was applied to the fully assembled cell for electrochemical testing.

[0092] Example 2 according to the present invention

[0093] The cell of Example 2 was obtained according to the protocol detailed in Comparative Example 1.

[0094] After assembly, the cell was charged to 4.5 V and held at this voltage for 1 hour. The cell was then opened by removing one of the stainless steel pistons on the cathode side and charged for 10 minutes. -2 It was placed under dynamic vacuum at 1000 mbar for 1 hour.

[0095] After this vacuum treatment, the cell was subjected to a pressure of 1100 kg / cm 2 And closed again.

[0096] Cyclic voltammetry

[0097] The cell of Comparative Example 1 and the cell of Example 2 according to the present invention were subjected to a cycle test at a rate of 0.5 mV / s between 1.6 V and 4.5 V.

[0098] The cyclic voltammetry graphs are shown in FIG. 1, where graph (a) corresponds to Comparative Example 1 and graph (b) corresponds to Example 2 according to the invention.

[0099] Part (a) of Figure 1 shows that a reversible electrochemical reaction occurs in the cell, while part (b) of Figure 1 shows that almost no electrochemical reaction occurs, indicating that various substances that cause the electrochemical characteristics of the untreated cell of Comparative Example 1 have been removed by the vacuum treatment.

[0100] Example 3 according to the present invention

[0101] The battery assembly was carried out in a cell consisting of a cylindrical polyetherimide (PEI) cell body and two 8 mm diameter stainless steel pistons.

[0102] The assembly work was carried out under an argon atmosphere in a glove box ([O2]<1 ppm, [H2O]<1 ppm).

[0103] A two electrode cell using a LiIn alloy anode was assembled as follows.

[0104] 80 mg of Li3YCl4Br2 at 1100 kg / cm 2 The mixture was cold pressed under a pressure of 0.05.

[0105] 10 mg / cm 2 The cathode composite (75:24:1 ratio of NMC811 / Li3YCl4Br2 / Carbon Super 65) was spread on the cathode side surface of the pressed Li3YCl4Br2. The stack was then pressurized to 1100 kg / cm 2 and further densified for 15 minutes.

[0106] Next, Li 0.5 A lithium indium complex, with the formula In, was added to the anode side, opposite the Li3YCl4Br2 pellet. Finally, the cell was loaded with a pressure of 1100 kg / cm 2 and closed it.

[0107] The battery was then maintained at 4.3V for 1 hour, then opened and charged for 10 minutes. -2 It was placed under dynamic vacuum at 1000 mbar for 1 hour.

[0108] The battery was then closed again and subjected to a pressure of 1100 kg / cm 2 After pressing again, a cycle test was performed at room temperature in the range of 1.8 V to 4.3 V at a rate of C / 20.

Claims

1. 1. A method for producing an all-solid-state battery element comprising a halide solid electrolyte, the method comprising the steps of: (a) an oxidation step of the all-solid-state battery element; and (b) a degassing step; A method comprising:

2. The degassing step is carried out to remove halogenated molecular species, particularly Cl ２ ,Br ２ and / or I ２ , preferably Br ２ and / or I ２ The method of claim 1 , comprising removing:

3. 3. The method according to claim 1 or 2, wherein the oxidation step is carried out for a time in the range of 10 minutes to 10 hours, in particular in the range of 30 minutes to 5 hours, preferably in the range of 45 minutes to 3 hours.

4. 4. The method according to any one of claims 1 to 3, wherein the degassing step comprises placing the all-solid-state battery element under a dynamic vacuum, preferably consisting of placing the all-solid-state battery element under a dynamic vacuum.

5. The dynamic vacuum is 10 －３ mbar~10 －１ mbar range, especially 5.10 －３ mbar ~ 5.10 －２ mbar range, preferably 7.10 －３ mbar ~ 2.10 －２ 5. The method of claim 4, wherein the pressure is maintained in the range of 1000 psi to 1000 psi.

6. 6. The method according to any one of claims 1 to 5, wherein the degassing step is carried out for a time in the range of 1 minute to 10 hours, in particular in the range of 5 minutes to 5 hours, preferably in the range of 10 minutes to 3 hours.

7. A method according to any one of claims 1 to 6, wherein the degassing step is carried out at a temperature in the range of from 15°C to 70°C, in particular from 20°C to 50°C, preferably from 25°C to 40°C.

8. The halide solid electrolyte has the following formula: M ３－ｚ (Me ｋ＋ ) ｆ X ３－ｚ＋ｋ＊ｆ is expressed as where −3≦z≦3, 2≦k<6, 0≦f≦1; M comprises an alkali metal element, in particular Li; Me comprises a divalent, trivalent, tetravalent, pentavalent or hexavalent metallic element or any combination thereof, in particular Me is: i. alkaline earth metals, such as Ba, Mg, Ca, Sr, 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, and iv. an element selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, and Ga; v. any combination thereof; is selected from X is a halogen, in particular selected from Cl, Br, I and any combination thereof; Preferably, the halide solid electrolyte is Li ３ InCl ６ and Li ３ Y(Cl,Br) ６ The method according to any one of claims 1 to 7, wherein the compound is selected from the group consisting of:

9. 9. The method according to claim 1, wherein the halide solid electrolyte is a polyhalide solid electrolyte, in particular comprising at least one of Cl and F and at least one of Br and I, preferably comprising Cl and Br.

10. 10. A method for producing an all-solid-state battery, said battery having, in order, an anode, at least one electrolyte layer, and a cathode, wherein a halide solid electrolyte as defined in any one of claims 1 to 8 is comprised in at least one of the electrolyte layers and / or in the cathode, said method comprising the following steps: (a) applying a voltage U to the all-solid-state battery, U = E + E ｒｅｆ where: E ｒｅｆ is the potential difference between the anode and a lithium metal anode; E is a voltage in the range of 3.0 V to 5.5 V, in particular in the range of 3.5 V to 4.0 V, preferably in the range of 4.0 V to 4.5 V, (b) a degassing step as defined in any one of claims 1 to 9, A method comprising:

11. 11. The method according to claim 10, wherein the voltage U is applied for a time in the range of 10 minutes to 10 hours, in particular in the range of 30 minutes to 5 hours, preferably in the range of 45 minutes to 3 hours.

12. 12. The method according to claim 10 or 11, wherein the degassing step preferably comprises opening the battery cell and placing the resulting open cell under dynamic vacuum.

13. After the degassing step, the cell is closed and subjected to a pressure of preferably 10 kg / cm ２ ~3000kg / cm ２ in the range of 500 kg / cm ２ ~1500kg / cm ２ The method according to any one of claims 10 to 12, wherein the pressing is carried out at a pressure in the range of

14. The cathode comprises a cathode active material selected from transition metal fluorides, polyanionic materials, fluorine-containing 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 cobalt oxide, lithium nickel cobalt aluminum oxide, or lithium nickel manganese cobalt oxide, preferably of the formula LiNi ０．６ Mn ０．２ Co ０．２ O ２ or LiNi ０．８ Mn ０．１ Co ０．１ The method according to any one of claims 10 to 13, wherein

15. The anode is: - oxides, nitrides, carbon, such as natural graphite, coke, engineered carbon, carbon fibers, spherical carbon, artificial graphite, amorphous carbon, metals, such as silicon, tin, sodium, lithium, their compounds and alloys, an anode active material selected from In particular, the anode active material is silicon, tin, lithium, compounds thereof, and alloys thereof, such as Li ｘ In ｙ wherein x is in the range of 0 to 1 and y is in the range of 0 to 1, and preferably the anode active material is selected from Li ０．５ The method according to any one of claims 10 to 14, wherein the metal is In or lithium.

16. An all-solid-state battery element or all-solid-state battery obtained by the method according to any one of claims 1 to 15.

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