Preparation method of all-solid-state battery pack

Abstract

The present invention relates to a method for preparing an all-solid-state battery (ASSB) element or ASSB comprising a halide solid electrolyte, wherein the method comprises an oxidation step and a venting step. The invention further relates to an ASSB element and an ASSB obtained with the method according to the invention.

Description

Technical Field

[0001] The present invention belongs to the field of all-solid-state rechargeable batteries (ASSBs), and in particular relates to a method for preparing said ASSBs containing a halide solid electrolyte. Background Art

[0002] ASSBs are of particular interest as an alternative to conventional lithium-ion battery packs, notably because they raise fewer safety concerns and have higher capacity or energy density.

[0003] To achieve ASSBs, a solid electrolyte is used instead of the liquid electrolyte present in lithium-ion batteries. ASSBs also use a Li metal anode and high-energy NMC cathode particles that are incorporated into the solid-state electrolyte.

[0004] Such solid electrolytes are, for example, selected from lithium thiophosphate (β-Li3PS4, LPS), argyrodite (Li6PS5Cl) as described in HJ Deiseroth et al., “Li6PS5X: a class of crystalline Li-rich solids with an unusually high Li+mobility.” Angew. Chem. Int. Ed., 47(2008), pp. 755-758 and as described in X. Li et al., “Air-stable Li3InCl6 electrolyte withhigh voltage compatibility for all-solid-state batteries.” Energy Environ. Sci., 2019, 12, pp. 2665-267; Schmidt, MO et al., “Zur Kristallstruktur vonLi3InCl6.” Zeitschrift für Anorg. und Allg. Chemie 1999, 625 (4), 539–540; and G. Meyer et al., “Handbook on the Physics & Chemistry of Rare Earths", V.28, chapter 177, 2000 Elsevier Sci., such as Li3InCl6.

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

[0006] Halide solid electrolytes are of particular interest because they exhibit good ionic conductivity (above 2 mS / cm) and better compactibility (deformability) than other solid inorganic electrolytes. Among these compounds, polyhalide solid electrolytes, i.e., those containing at least two halide ions (e.g., Cl and Br), are particularly interesting because heavier halides such as Br and I contribute to the high conductivity of the electrolyte, while lighter halides such as Cl and F have higher electrochemical stability at high potentials.

[0007] However, the present inventors have unexpectedly discovered that when a halide solid electrolyte, particularly a polyhalide solid electrolyte, is subjected to a high potential, species are formed by the degradation of the electrolyte. The species have been identified as halogenated molecular species, such as Br2 and I2.

[0008] These species are very oxidizing and can cause reactions with various components of an ASSB, such as its electrode active materials or current collectors, which can reduce the capacity or life of the battery. In addition, when the species are in a gaseous state, they can cause potentially dangerous overpressure in the battery cells. Summary of the Invention

[0009] Technical issues As identified by the present inventors, in situ formation of species may lead to several problems.

[0010] The present invention therefore provides a remedy to the technical problem identified above by: - Improved battery pack safety, - Improved battery capacity and lifespan, - Enable the use of halide solid electrolytes, especially polyhalide solid electrolytes, in ASSBs.

[0011] The present invention is further easily implemented in a process for the preparation of ASSB components or ASSBs themselves, in particular on an industrial scale.

[0012] A preparation method is understood to mean any method which aims at “preparing” an ASSB element or the ASSB itself, ie such that it can be suitably used and / or functioned after having been subjected to the method according to the invention.

[0013] Solutions to technical problems Therefore, according to a first aspect, the present invention relates to a method for preparing an all-solid-state battery element comprising a halide solid electrolyte, characterized in that the method comprises: a) Oxidation steps for all-solid-state battery components, and b) Exhaust step.

[0014] The oxidation step according to the invention can be carried out by applying a tensile force or, advantageously in the case of ASSB elements, by treatment with an oxidizing gas such as Cl 2 .

[0015] According to a second aspect, the present invention also relates to a method for preparing an all-solid-state battery, wherein the all-solid-state battery comprises an anode, at least one electrolyte layer and a cathode in sequence, wherein the halide solid electrolyte is contained in at least one electrolyte layer and / or the cathode, wherein the method comprises: a) applying a tension U to the all-solid-state battery pack, wherein U = E + E ref in E ref , the potential difference between the anode and the lithium metal anode, and E 3.0 V to 5.5 V, in particular 3.5 V to 4.0 V, preferably 4.0 V to 4.5 V, and b) an exhaust step as defined herein.

[0016] The invention also relates to an all-solid-state battery element comprising a halide solid electrolyte and an all-solid-state battery obtained with the method according to the invention.

[0017] The venting step implemented in the method according to the invention makes it possible to eliminate from the battery cells species formed in situ under normal conditions of use.

[0018] Advantages of the present invention First, by eliminating the species, the internal pressure of the battery cell is reduced to prevent any leakage.

[0019] Furthermore, these species are strong oxidants that can react with several components of an ASSB, such as the electrode active materials, e.g., lithium-nickel-manganese-cobalt oxide at the cathode, or the current collector. The present invention is able to prevent such reactions and thereby any associated reduction in the capacity and / or lifetime of the ASSB by removing these species.

[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 these species, which is a major drawback of polyhalide solid electrolytes. The present invention thus enables the use of these materials without negatively impacting the resulting ASSBs.

[0021] Finally, the present invention is easily implemented in a battery production line. In fact, although ASSBs have not yet been identified as requiring venting, lithium-ion batteries are typically subjected to a venting step to remove gases formed during the battery formation phase.

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

[0023] However, to the best of the inventors' knowledge, the decomposition of the electrolyte into different species in ASSBs is unexpected and it is generally believed that a venting step (which may also be referred to as a degassing step) is not necessary (see, e.g., Fraunhofer ISI, Solid-state battery roadmap 2035+, April 2022).

[0024] Strauss, F, ACS Appl. Mater. Interfaces 2020, 12, 20462-20468 reported some cases of gas formation in ASSBs that were also confirmed in lithium-ion batteries. However, this gas formation originated from the degradation of the cathode active material. On the other hand, the present invention is not related to the cathode active material, as it only concerns species formed by the controlled electrochemical preparation of the halide solid electrolyte that occurs before any actual cycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a graphical representation of the cyclic voltammetry performed on a) a pristine cell corresponding to Comparative Example 1 and b) a degassed cell according to Example 2 of the present invention in the following examples, wherein x The axis represents the potential applied to the battery, y The axis represents the intensity of the measured current. DETAILED DESCRIPTION

[0026] The present invention can be applied to any ASSB component comprising a halide solid electrolyte. An ASSB component can refer to any component present in or suitable for obtaining an ASSB. Preferably, the present invention is applied to the electrolyte layer, the cathode electrolyte (i.e., a mixture of cathode active material and electrolyte), or the electrolyte material itself. The electrolyte material can be in the form of a powder, a paste containing the powder, or a slurry.

[0027] Thus, the ASSB element or ASSB obtained with the method according to the invention may comprise a halide solid electrolyte as described in detail below.

[0028] In the ASSB according to the invention or the ASSB used in the method according to the invention, a halide solid electrolyte may be contained in the cathode and / or the electrolyte layer.

[0029] Halide solid electrolytes 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, and 2≤k<6, 0≤f≤1; - M includes alkali metal elements, especially Li; - Me includes metals other than alkali metals, and - X is a halogen.

[0030] In a particular embodiment, f is different from zero.

[0031] In a particular embodiment, Me includes more than one metal element, and k can be the average of the total valence of each metal element. For example, when Me includes equimolar amounts of a trivalent element and a tetravalent element, k = (3 + 4) / 2 = 3.5. In particular, k can be 2, 3, 4, or 5.

[0032] It is understood that atomic vacancies may exist within the unit cell of the halide solid electrolyte. In this case, the atomic vacancies may be represented as M in the formula of the solid halide 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 empty atomic positions. In a particular embodiment, y may be f*(k-1).

[0033] In a particular embodiment, M may include Li, Na, K, Rb, Cs, or any combination thereof. For example, M may include at least one of Li and Na, or a combination thereof. In a further aspect, M may consist of at least one alkali metal element. For example, M may consist essentially of at least one alkali metal element selected from Li, Na, K, Rb, and Cs. In another example, M may consist of Li. In yet another example, M may consist of Li and at least one of Na, K, Rb, and Cs. In yet another example, M may consist of Na and at least one of Cs and Rb. In another example, M may consist of at least one of Na and Cs.

[0034] In a particular embodiment, Me may include alkaline earth metal elements, rare earth elements, 3d transition metals, elements 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 alkaline earth metals, including Ba, Mg, Ca, and Sr, or any combination thereof. In another example, Me may include rare earth elements, 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 3d transition metals, in particular, selected from Zn, Cu, V, and any combination thereof. In yet another example, Me may include elements selected from Zr, Ti, Sn, Th, Ge, Ta, Nb, Mo, W, Sb, Te, In, Bi, Al, Ga, and any combination thereof.

[0035] In a particular embodiment, X may comprise a halogen, in particular selected from Cl, Br, I, and any combination thereof. In one example, X may comprise at least one of Cl and Br. Preferably, X may consist of Cl, Br, or any combination thereof. In a particularly preferred embodiment, X consists of Cl and Br.

[0036] Accordingly, the all-solid-state battery element or all-solid-state battery according to the present invention or used in the method according to the present invention may comprise a halide solid electrolyte of the formula M 3-z (Me k+ ) f X 3-z+k*f Where -3≤z≤3, 2≤k<6, 0≤f≤1; - M includes alkali metal elements, especially Li; - Me includes a divalent, trivalent, tetravalent, pentavalent or hexavalent metal element or any combination thereof, in particular, Me is selected from: i. Alkaline earth metals, including 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, Ga, and v. any combination thereof, and - X is 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.

[0037] Herein, it is to be understood that, for example in Li3Y(Cl,Br)6, (Cl,Br)6 means that any combination of Cl and Br may be present in the compound, wherein the sum of the stoichiometric coefficients of Cl and Br is equal to 6.

[0038] In a particular embodiment, the halide solid electrolyte may be composed of 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 includes Y, Gd, Yb, In, Sc, Zn, Mg, Ca, Ba, Sn, or a combination thereof, and X is Cl, Br, or a combination thereof.

[0039] In a specific embodiment, 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, the halide solid electrolyte comprises at least Cl and Br.

[0040] In this context, “polyhalide solid electrolyte” is understood to mean a halide solid electrolyte comprising at least two halide ions.

[0041] In one specific embodiment, 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 be composed of at least one of the above-mentioned metal elements having a valence of 3. Me may include at least one of the above-mentioned metal elements, wherein the average valence of the at least one metal element is 3.

[0042] In another specific embodiment, the solid halide electrolyte may be composed of Li, Y, In, and at least one of Cl and Br. For example, the solid halide electrolyte may be composed of Li, Y, In, and Cl. In another example, the solid halide electrolyte may be composed of Li, Y, In, and Br. In a preferred example, the solid halide electrolyte may be composed of Li, Y, In, Cl, and Br. In a specific example, the solid halide electrolyte may 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 represents, where 0 <x≤0.5。

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

[0044] In another specific embodiment, the solid halide electrolyte may be composed of Li, Gd, and at least one of Cl and Br. For example, the solid halide electrolyte may be composed of Li, Gd, and Cl. In another example, the solid halide electrolyte may be composed of Li, Gd, and Br. In yet another example, the solid halide electrolyte may be composed of Li, Gd, Cl, and Br. In a specific example, the solid halide electrolyte may be composed of Li 3x Gd 1-x Cl3、Li 3x Gd 1-x Br3 or Li 3x Gd 1-x (Cl,Br)3, where 0.01≤x<1.

[0045] In another specific embodiment, the solid halide electrolyte may be composed of Li, In, and at least one of Cl and Br. For example, the solid halide electrolyte may be composed of Li, In, and Cl. In another example, the solid halide electrolyte may be composed of Li, In, and Br. In yet another example, the solid halide electrolyte may be composed of Li, In, Cl, and Br. In a specific example, the solid halide electrolyte may be composed of Li 3x In 1-x Cl3、Li 3x In 1-x Br3 or Li 3x In 1-x (Cl,Br)3, where 0≤x<0.5.

[0046] Solid halide electrolytes can be selected from Li3InCl6, Li3InBr6, Li3In(Cl,Br)6, Li3YCl6, Li3YBr6, Li3Y(Cl,Br)6, Li 2.7 Y 0.7 Zr0.3 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 / 3Zr 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 Cl�, 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 or Li3In 0.5 Y 0.5 Cl6.

[0047] The solid halide electrolyte can be selected from Li3InCl6, Li3InBr6, Li3In(Cl, Br)6, Li3YCl6, Li3YBr6, Li3Y(Cl, Br)6, 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 / 3Zr 1 / 3 Mg 1 / 3 Cl6, Li3Y 1 / 3 Sn 1 / 3 Mg 1 / 3Cl6、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 or Li3In 0.5 Y 0.5 Cl6、Li3Y 0.75 In 0.25 Cl4Br2、Li3Y 0.8 In 0.2 Cl4Br2、Li3Y 0.85 In 0.15 Cl4Br2、Li3Y 0.9 In 0.1 Cl4Br2、Li3Y 0.85 In 0.15 Cl 3.5 Br 2.5 and Li3Y 0.985 In 0.015 Cl4Br2.

[0048] anode In ASSBs, the anode active material is a material capable of storing and releasing metal ions, particularly alkali metal ions such as Li or Na ions.

[0049] As the anode active material, metal, carbon, oxide or nitride can be used.

[0050] The metal suitable for use as the anode active material may be a single metal or an alloy, such as lithium metal or a lithium alloy. The metal suitable for use as the anode active material may be selected from silicon, tin, silicon compounds, tin compounds, lithium and lithium alloys.

[0051] Examples of carbon suitable for use as the anode active material include natural graphite, coke, developing carbon, carbon fiber, spherical carbon, artificial graphite, and amorphous carbon.

[0052] Therefore, in the all-solid-state battery according to the present invention or the all-solid-state battery used in the method according to the present invention, the anode active material may be selected from: - oxides, - nitrides, - Carbon, such as natural graphite, coke, mesophase carbon, carbon fiber, spherical carbon, artificial graphite and amorphous carbon, - metals such as silicon, tin, sodium or lithium, their compounds and their alloys, In particular, the anode active material is selected from silicon, tin, lithium, their compounds and their alloys, such as Li x In y , wherein x is 0 to 1, and y is 0 to 1, preferably, the anode active material is Li 0.5 In or lithium.

[0053] The thickness of the ASSB according to the invention or the anode used in the ASSB according to the method according to the invention may be from 10 μm to 500 μm.

[0054] At least one of the anode and the cathode may comprise 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, and the electron conductor is preferably vapor-grown carbon fibers.

[0055] cathode In the all-solid-state battery according to the present invention or the all-solid-state battery used in the method according to the present invention, the cathode composite material may comprise a cathode active material and a halide solid electrolyte as described above.

[0056] The cathode active material is a material that is capable of storing and releasing metal ions, particularly alkali metal ions such as Li or Na ions.

[0057] As cathode active materials, doped or undoped, coated or uncoated 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 can be used. In particular, the cathode active material can be a transition metal oxide such as lithium-cobalt oxide, lithium-nickel-cobalt-aluminum oxide or lithium-nickel-manganese-cobalt oxide. Transition metal oxides suitable for use as cathode active materials can be, for example, LiNi 0.6 Mn 0.2 Co 0.2 O2, Li(NiCoAl)O2 and LiCoO2. Preferably, the cathode active material is of the formula LiNi 0.6 Mn 0.2 Co 0.2O2 or LiNi 0.8 Mn 0.1 Co 0.1 transition metal oxides.

[0058] The cathode active material may be present in the ASSB according to the present invention in the form of particles. The median diameter of the anode active material particles may be 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.

[0059] The thickness of the ASSB according to the invention or the anode used in the ASSB according to the method according to the invention may be from 10 μm to 500 μm.

[0060] At least one of the anode and the cathode may comprise 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, and the electron conductor is preferably vapor-grown carbon fibers.

[0061] Therefore, in the all-solid-state battery according to the present invention or the all-solid-state battery used in the method according to the present invention, the cathode may comprise a cathode active material selected from doped or undoped, coated or uncoated 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, 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 O2 or LiNi 0.8 Mn 0.1 Co 0.1 Those.

[0062] Preparation method An all-solid-state battery element or an all-solid-state battery according to the invention or for use in the method according to the invention is first obtained by steps known to a person skilled in the art to obtain said element or ASSB comprising the desired materials.

[0063] The present invention consists in adding a further degassing step to the methods known in the art. In this context, "degassing steps" used in the plural are intended to include both the oxidation step (in the case of ASSB, in particular the application of tension) and the actual degassing step.

[0064] The degassing step is intended to remove any species formed by electrochemical reactions within the ASSB, in particular by electrochemical reactions of the halide solid electrolyte, preferably polyhalide solid electrolyte, contained in the anode and / or electrolyte layer of the ASSB.

[0065] As indicated in the description of halide solid electrolytes suitable for use in the present invention, the species formed may be halogenated molecular species, namely F2, Cl2, Br2 and I2.

[0066] In a preferred embodiment of the present invention, the degassing step comprises the elimination of halogenated molecular species, in particular Cl2, Br2 and / or I2, preferably Br2 and / or I2.

[0067] “Eliminate” is understood to mean removing the species from contact with an ASSB element or ASSB, for example in the case of an ASSB, removing the species from the housing.

[0068] The oxidation step may be carried out for a duration of 10 minutes to 10 hours, in particular 30 minutes to 5 hours, preferably 45 minutes to 3 hours.

[0069] The oxidation step may comprise 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; gaseous Cl2 may then be introduced, for example, at a pressure of 0.1 to 10 mbar, and the furnace may be heated to a temperature of 100 to 300°C for a duration corresponding to the duration of the oxidation step as described above. When the gas flow stops, the furnace may be evacuated to 10 -5 to 10 -3 The ASSB component can then be introduced into an inert atmosphere, such as an inert atmosphere consisting essentially of nitrogen, argon, or a mixture thereof, such as a glove box.

[0070] The tension is the tension U defined by the following relationship, U = E + E ref in E ref is the potential difference between the anode of the ASSB and the lithium metal anode, and E is a tension of 3.0 V to 5.5 V, particularly 3.5 V to 4.0 V, preferably 4.0 V to 4.5 V.

[0071] In a particular embodiment of the present invention, the tensioning force U is applied for a duration of 10 minutes to 10 hours, in particular 30 minutes to 5 hours, preferably 45 minutes to 3 hours.

[0072] When applied to ASSB components, the venting step may include, and preferably consists in, placing the all-solid-state battery component under a dynamic vacuum.

[0073] When applied to ASSBs, the venting step may comprise, and preferably consists in, opening the battery cells and placing the resulting opened cells under a dynamic vacuum.

[0074] In both cases, the dynamic vacuum can be maintained at 10 -3 mbar to 10 -1 millibars, especially 5*10 -3 mbar to 5*10 -2 mbar, preferably 7*10 -3 mbar to 2*10 -2 millibar pressure.

[0075] In a particular embodiment of the present invention, the degassing step is carried out for a duration of 1 minute to 10 hours, in particular 5 minutes to 5 hours, preferably 10 minutes to 3 hours.

[0076] In a particular embodiment of the present invention, the degassing step may be performed at a temperature of 15 to 70°C, in particular 20 to 50°C, preferably 25 to 40°C.

[0077] In a particular embodiment of the invention, after the venting step, the battery is closed and preferably heated at 250 kg.cm -2 Up to 3000 kg.cm -2 , especially 500 kg.cm -2 Up to 1500 kg.cm -2 Pressurize under pressure.

[0078] The battery can be closed and pressurized under an inert atmosphere, preferably under argon.

[0079] The process according to the present invention is further illustrated by the following examples.

[0080] Comparative Example 1 Cell 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.

[0081] The assembly process was carried out in a glove box under argon atmosphere ([O2] < 1 ppm, [H2O] < 1 ppm).

[0082] The two-electrode cell was assembled as follows.

[0083] 80 mg Li3YCl4Br2 was spread and -2 Cold pressing.

[0084] 10 mg.cm - The cathode composite material (Li3YCl4Br2 / carbon super C65 in a ratio of 90:10) was spread onto the surface of the cathode side of the pressed Li3YCl4Br2. The stack was then heated at 1100 kg.cm -2 The mixture was further densified for 15 minutes.

[0085] Next, the formula Li 0.5 A lithium-indium composite of In was added as a counter electrode to the opposite side of the Li3YCl4Br2 pellets, i.e., the anode side.

[0086] Finally, the entire stack was further densified at 4 t / cm² for 15 minutes. After compression, a force of 1100 kg.cm was applied to the fully assembled cell for electrochemical studies. - ² pressure.

[0087] Embodiment 2 according to the present invention The battery of Example 2 was obtained according to the protocol detailed in Comparative Example 1.

[0088] After assembly, the cells were charged to 4.5 V and held at this voltage for 1 hour. The cells were then opened on the cathode side by removing one of the stainless steel pistons and placed in a 10 -2 mbar dynamic vacuum for 1 hour.

[0089] After this vacuum treatment, the -2 Next, turn off the battery.

[0090] Cyclic voltammetry The battery of Comparative Example 1 and Example 2 according to the present invention has a peak current of 0.5 mV.s at a voltage of 1.6 V to 4.5 V. -1 The rate cycle.

[0091] exist Figure 1 A graphical representation of the cyclic voltammetry is given in FIG. 1 , wherein FIG. a) corresponds to Comparative Example 1 and FIG. b) corresponds to Example 2 according to the present invention.

[0092] Figure 1 Part a) shows that a reversible electrochemical process occurs in the battery, and the Figure 1 Part b) shows almost no electrochemical activity. This proves that the species causing the electrochemical signature in the original battery of Comparative Example 1 were eliminated by vacuum.

[0093] Embodiment 3 according to the present invention Cell 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.

[0094] The assembly process was carried out in a glove box under argon atmosphere ([O2] < 1 ppm, [H2O] < 1 ppm).

[0095] A two-electrode cell using a LiIn alloy anode was assembled as follows.

[0096] 80 mg Li3YCl4Br2 was spread and heated at 1100 kg.cm -2 . Cold pressing.

[0097] 10 mg.cm - The cathode composite material (NMC811 / Li3YCl4Br2 / Carbon Super 65 in a ratio of 75:24:1) was spread onto the cathode side surface of the pressed Li3YCl4Br2. The stack was then heated at 1100 kg.cm -2 The mixture was further densified for 15 minutes.

[0098] Next, the formula Li 0.5 The lithium-indium composite material of In was added to the opposite side of the Li3YCl4Br2 pellets, i.e. the anode side. Finally, the cell was heated at 1100 kg.cm -2 Next close.

[0099] The battery pack was then kept at 4.3 V for 1 hour and then opened and placed at 10 -2 mbar dynamic vacuum for 1 hour.

[0100] Then close the battery again and run at 1100 kg.cm -2 The cells were re-pressurized and then cycled between 1.8 V and 4.3 V at room temperature at a rate of C / 20.

Claims

1. A method for preparing an all-solid-state battery element comprising a halide solid electrolyte, characterized in that The method comprises: a) Oxidation steps for all-solid-state battery components, and b) Exhaust step.

2. The method according to any one of the preceding claims, wherein the degassing step comprises eliminating halogenated molecular species, in particular Cl2, Br2 and / or I2, preferably Br2 and / or I2.

3. The process according to any one of the preceding claims, wherein the oxidation step is carried out for a duration of 10 minutes to 10 hours, in particular 30 minutes to 5 hours, preferably 45 minutes to 3 hours.

4. The method according to any of the preceding claims, wherein the venting step comprises, preferably consists in, placing the all-solid-state battery component under a dynamic vacuum.

5. The method according to the preceding claim, wherein the dynamic vacuum is maintained at 10 -3 mbar to 10 -1 millibars, especially 5*10 -3 mbar to 5*10 -2 mbar, preferably 7*10 -3 mbar to 2*10 -2 millibar pressure.

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

7. The method according to any one of the preceding claims, wherein the degassing step is performed at a temperature of 15 to 70°C, in particular 20 to 50°C, preferably 25 to 40°C.

8. The method according to any one of the preceding claims, wherein the halide solid electrolyte is of the formula M 3-z (Me k+ ) f X 3-z+k*f Where -3≤z≤3, 2≤k<6, 0≤f≤1; - M includes alkali metal elements, especially Li; - Me includes a divalent, trivalent, tetravalent, pentavalent or hexavalent metal element or any combination thereof, in particular, Me is selected from: i. Alkaline earth metals, including 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, Ga, and v. any combination thereof, and - X is 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.

9. The method according to any one of the preceding claims, 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, the halide solid electrolyte comprises at least Cl and Br.

10. A method for preparing an all-solid-state battery, the battery comprising, in sequence, an anode, at least one electrolyte layer, and a cathode, wherein the halide solid electrolyte as defined in any one of the preceding claims is contained in at least one electrolyte layer and / or the cathode, characterized in that The preparation method comprises: a) applying a tension U to the all-solid-state battery pack, wherein U = E + E ref in E ref , the potential difference between the anode and the lithium metal anode, and E 3.0 V to 5.5 V, in particular 3.5 V to 4.0 V, preferably 4.0 V to 4.5 V, and b) A degassing step as defined in any one of the preceding claims.

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

12. The method according to any one of claims 10 or 11, wherein the venting step comprises, preferably consists in, opening the battery cell and placing the resulting opened cell under a dynamic vacuum.

13. The method according to any one of claims 10 to 12, wherein after the venting step, the battery pack is closed and preferably at 10 kg.cm -2 Up to 3000 kg.cm -2 , especially 500 kg.cm -2 Up to 1500 kg.cm -2 Pressurize under pressure.

14. The method according to any one of claims 10 to 13, wherein the cathode comprises a cathode active material selected from the group consisting of doped or undoped, coated or uncoated 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, 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 O2 or LiNi 0.8 Mn 0.1 Co 0.1 Those.

15. The method according to any one of claims 10 to 14, wherein the anode comprises an anode active material selected from: - oxides, - nitrides, - Carbon, such as natural graphite, coke, mesophase carbon, carbon fiber, spherical carbon, artificial graphite and amorphous carbon, - metals such as silicon, tin, sodium or lithium, their compounds and their alloys, In particular, the anode active material is selected from silicon, tin, lithium, their compounds and their alloys, such as Li x In y , wherein x is 0 to 1, and y is 0 to 1, preferably, the anode active material is Li 0.5 In or lithium.

16. An all-solid-state battery element or an all-solid-state battery obtainable by the method according to any one of the preceding claims.

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