solid composite electrolyte

Abstract

The present invention provides i) at least one solid inorganic particle; ii) at least one ionic liquid electrolyte; iii) at least one non-ion-conducting polymer; wherein i) at least one solid inorganic particle is ionically conductive, and ii) is blended with at least one ionic liquid electrolyte. The present invention also relates to a method for producing the solid composite electrolyte, a solid-state battery comprising the solid composite electrolyte, and the use of the solid composite electrolyte in a solid-state battery to improve ionic conductivity and mechanical properties.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application Publication No. 18215742.0, filed December 21, 2018, the entire contents of which are incorporated herein by reference. To the extent that the disclosures of any patents, patent applications, and publications incorporated herein by reference conflict with the statements of this application to the extent that a term may become unclear, the statements of this application shall control.

[0002] The present invention relates to a solid composite electrolyte comprising i) at least one solid inorganic particle, ii) at least one ionic liquid electrolyte, and iii) at least one non-ion-conducting polymer, wherein i) the at least one solid inorganic particle is ion-conductive and ii) is blended with the at least one ionic liquid electrolyte. [Background technology]

[0003] Li-ion batteries have dominated the market for rechargeable energy storage devices for over 20 years due to their light weight, moderate energy density, and excellent cycle life. Nevertheless, current Li-ion batteries still suffer from poor safety and relatively low energy density, which is required for high-power applications such as electric vehicles (EVs), hybrid electric vehicles (HEVs), and grid energy storage. These drawbacks are due to the presence of a liquid electrolyte.

[0004] Conventional Li-ion batteries use organic carbonate-based liquid electrolytes, which make them prone to leaking and producing flammable volatile gas species.

[0005] Therefore, solid-state batteries (SSBs) are considered to be the next generation of energy storage devices because they offer higher energy density and are safer than conventional Li-ion batteries with liquid electrolyte systems. In SSBs, the highly flammable liquid electrolyte is replaced by a solid electrolyte, virtually eliminating any risk of fire and / or explosion.

[0006] There are three types of solid electrolytes: inorganic electrolytes, polymer electrolytes, and composite electrolytes. Inorganic electrolytes exhibit high ionic conductivity but are brittle due to poor mechanical properties. Ceramic-based inorganic electrolytes, such as garnet-type Li-ion conductive materials, suffer from poor grain boundary conductivity. These materials rely on a sintering process to fuse particles and establish conductive paths. Only hot pressing has been successful in shortening the sintering time, but this requires specialized and expensive equipment, which poses an obstacle to mass production on a commercial scale. Furthermore, the feasibility of forming thin films by hot pressing has yet to be demonstrated.

[0007] Although dry polymer electrolytes exhibit excellent mechanical properties and processability, they suffer from the drawback of low ionic conductivity. Prior art polymer-based conductors, such as high molecular weight poly(ethylene oxide) with dissolved Li salts, have two major drawbacks. First, due to the crystalline nature of the polymer, sufficient conductivity is only obtained above the melting temperature, limiting their applicability to high-temperature applications. Second, such polymer electrolytes must be plasticized by adding salts, resulting in very poor mechanical properties.

[0008] Solid inorganic ions (Li) dispersed in a polymer matrix +Composite electrolytes consisting of conductive particles (SIC particles) offer the possibility of combining high ionic conductivity with excellent mechanical properties. Despite the fact that composite electrolytes offer the possibility of overcoming the shortcomings of inorganic and polymer electrolytes, engineering / designing the chemistry of the polymer and inorganic surfaces has proven to be much more complicated than expected. It is well known that the main difficulty with solid (composite) electrolytes is the contact resistance between the particles, which results in a low overall ionic conductivity of the solid electrolyte. This is especially true in the case of composite electrolytes using garnet-type ceramic-based electrolyte particles.

[0009] In most currently developed composite electrolytes, the addition of SiC particles to the polymer electrolyte can improve the conductivity of the solid composite electrolyte. However, as Chen, L. et al. explain in Nano Energy, 2018.46:pp.176-184 ("PEO garnet composite electrolytes for solid-state lithium batteries"), the improvement in conductivity is due to the improved ionic conductivity of the polymer phase, not the conductivity of the SiC particles. Typically, the improvement in ionic conductivity is only observed in composites with low SiC particle loadings. As the SiC loading begins to increase, the overall conductivity quickly decreases, a clear indication of problematic interparticle resistance.

[0010] Several attempts have been made to overcome the poor performance of composite electrolytes.

[0011] 1. Addition of liquid electrolyte to the interface between the solid electrolyte and the electrode In Nano Energy, 2018.45:pp.413-419 ("A durable and safe solid-state lithium battery with a hybrid electrolyte") and in Chemelectrochem, 2018.5:pp.2873-2881 ("A ceramic-PVDF composite membrane with modified interfaces as an ion-conducting electrolyte for solid-state lithium-ion batteries operating at room temperature"), Zhang et al. reported that they were able to increase the ionic conductivity of PVDF / LLZO composites by adding / permeating a liquid electrolyte into the interface between the solid composite electrolyte membrane and the electrodes (on both sides). Although Zhang et al. succeeded in improving the ionic conductivity of the composite electrolyte, the origin of the conductivity is via the liquid electrolyte absorbed into the polymer phase. It is well known that the conductivity of ceramic-polymer composites with low ceramic loadings is mediated by the polymer phase, not the ceramic phase, and that the addition of a liquid electrolyte to a solid polymer electrolyte leads to the formation of a gel-like structure, with ionic conductivity being mediated by the liquid or gelled phase.

[0012] Furthermore, the addition of conventional organic liquid electrolytes does not eliminate the risk of flammability of the battery assembly.

[0013] 2. Addition of liquid electrolyte to composite material (gel composite electrolyte) The strategy adopted to overcome the low conductivity of ceramic-polymer composite electrolytes is to incorporate a large amount of liquid electrolyte into the composite structure. Since the porous polymer separator is filled with liquid electrolyte, Jung et al., Journal of Power Sources, 2015.293:pp.675-683 ("Ceramic separators based on Li +-conducting inorganic electrolyte for high-performance lithium-ion batteries with enhanced safety”), Li7La3Zr2O 12 We reported the fabrication of highly filled ceramic separators composed of LLZO (80–90 weight percent (wt%)) and PVDF-HFP. To obtain specific ionic conductivities, these porous composites were filled with a conventional liquid electrolyte (1.15 M LiPF6 in ethylene carbonate / diethyl carbonate). While fairly good ionic conductivities were obtained, it was clear that the ionic conductivity was derived from the liquid or gelled phase. Furthermore, as with the previous strategies detailed above, these hybrid structures still contained large amounts of flammable organic liquids, posing a potential flammability risk for battery assemblies.

[0014] 3. Formation of hybrids between LLZO and ionic liquids (electrolytes) A hybrid electrolyte consisting of LLZO particles (80 wt%) embedded in an ionic liquid-based electrolyte (Pyr14TFSI + LiTFSI) (20 wt%) was reported by Kim et al. in J. Mater. Chem. a' 2016.4: pp. 17025-17032 ("Hybrid solid electrolyte with the combination of Li7La3Zr2O 12 The liquid was developed in the "Ceramic and Ionic Liquid for High Voltage Pseudo-Solid State Li-ion Batteries" project. -4 Although promising ionic conductivities of S / cm have been obtained, this hybrid electrolyte cannot be used alone due to its very poor mechanical properties.

[0015] Other attempts have included creating similar hybrid structures of LLZO and Pyr14TFSI ionic liquid. However, these hybrid structures did not contain enough ionic liquid to bind the LLZO powder together. As a result, the hybrid structures had to be cold-pressed to produce pellets, resulting in very poor mechanical properties.

[0016] The use of solid electrolytes instead of liquid electrolytes has been investigated. For example, R. Sudo et al., Solid State Ionics, 262, 151 (2014), reported on the use of Al-doped Li7La3Zr2O as a solid electrolyte for electrochemical cells containing lithium anodes. 12 However, another drawback of lithium dendrite formation has been observed.

[0017] Therefore, there remains a need for new solid electrolytes that have high ionic conductivity, good mechanical properties, good processability, and low inter-particle resistance without the use of volatile and flammable organic liquids.

[0018] Therefore, there is a need for a solid electrolyte with improved ionic conductivity, improved inter-particle contact resistance, and excellent mechanical properties that can be easily processed. The developed solid composite electrolyte does not contain any flammable or volatile additives, eliminating the risk of fire and explosion. The developed solid composite electrolyte is composed of solid, ionically conductive inorganic particles blended with an ionic liquid electrolyte. To reduce the inter-particle resistance between the solid, ionically conductive inorganic particles, the solid inorganic particles need to be blended with the ionic liquid electrolyte such that at least a portion of the ionic liquid electrolyte covers at least a portion of the surface of the solid inorganic particles. Summary of the Invention

[0019] The first object of the present invention is to i) at least one solid inorganic particle; ii) at least one ionic liquid electrolyte; iii) at least one non-ion-conducting polymer; wherein i) at least one solid inorganic particle is ionically conductive, and ii) is blended with at least one ionic liquid electrolyte.

[0020] According to one embodiment, i) the at least one solid inorganic particle is a garnet-type inorganic particle.

[0021] In one embodiment, the amount of i) at least one type of solid inorganic particles is 60.0 to 98.0 wt % based on the total weight of the solid composite electrolyte. In a preferred embodiment, the amount of i) at least one type of solid inorganic particles is 70.0 to 95.0 wt % based on the total weight of the solid composite electrolyte. In a more preferred embodiment, the amount of i) at least one type of solid inorganic particles is 80.0 to 92.0 wt % based on the total weight of the solid composite electrolyte.

[0022] A second object of the present invention is a method for producing the above-mentioned solid composite electrolyte.

[0023] A third object of the present invention is a solid state battery comprising the above-mentioned solid composite electrolyte.

[0024] A fourth object of the present invention is the use of the above-mentioned solid composite electrolyte in a solid-state battery to improve ionic conductivity and mechanical properties.

[0025] Surprisingly, the present inventors have found that a particularly advantageous combination of properties, such as ionic conductivity and mechanical properties, can be achieved with a solid composite electrolyte comprising i) at least one solid inorganic particle, ii) at least one ionic liquid electrolyte, and iii) at least one non-ion-conducting polymer, where i) the at least one solid inorganic particle is ion-conductive and ii) is blended with the at least one ionic liquid electrolyte. It is believed that blending i) the at least one solid inorganic particle with ii) the at least one ionic liquid electrolyte effectively reduces the inter-particle resistance of the solid composite electrolyte. Even more surprisingly, such a solid composite electrolyte was obtained without the use of an ion-conducting binder. [Brief explanation of the drawings]

[0026] [Figure 1] Cross-sectional view of the AC impedance spectroscopy pressure cell developed within Solvay to measure the ionic conductivity of membranes. In the pressure cell, the membrane is pressed between two stainless steel electrodes during impedance measurements. DETAILED DESCRIPTION OF THE INVENTION

[0027] The following components of the solid composite electrolyte according to the present invention are described in detail below. It should be understood that both the foregoing summary and the following detailed description are exemplary and are intended to provide further explanation of the claimed invention. Accordingly, various changes and modifications described herein will be apparent to those skilled in the art. Furthermore, for the sake of clarity and conciseness, descriptions of well-known functions and structures may be omitted.

[0028] In the present invention, the term "solid composite electrolyte" refers to a lithium-ion conductive composite material that has a free-standing shape at room temperature without a support and may be in the form of a foldable, flexible, free-standing membrane. The solid composite electrolyte according to the present invention does not flow to take the shape of its container or expand to fill the entire available volume. On the other hand, due to its flexibility, the solid composite electrolyte according to the present invention can be shaped in various ways and can therefore accommodate changes in either volume or shape that may occur during charging and discharging of a lithium battery.

[0029] solid inorganic particles The solid composite electrolyte according to the present invention comprises i) at least one type of solid inorganic particles. According to a first embodiment of the present invention, the i) at least one type of solid inorganic particles are garnet-type inorganic particles. According to a second embodiment of the present invention, the i) at least one type of solid inorganic particles are non-garnet-type oxide inorganic particles. According to a third embodiment of the present invention, the i) at least one type of solid inorganic particles are phosphate inorganic particles.

[0030] As used herein, the term "garnet" refers to the atomic structure of a crystalline or partially crystalline oxide ceramic solid.

[0031] In one embodiment, the garnet-type inorganic particles are M 1 a M 2 b M 3 c O d (In the formula, M 1 is a first cationic element selected from the group consisting of H, Li, Na, Mg, Al and Ga, preferably Li; M 2 is a second cationic element selected from the group consisting of La, Ba, Sr, Ca, In, Mg, Y, Sc, Cr, Al, K, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; M 3is a third cationic element selected from the group consisting of Zr, Ta, Nb, Sb, Sn, Hf, Bi, W, Si, Se, Ga, and Ge; and a, b, c, and d are positive numbers including various combinations of integers and decimals) has the general formula of

[0032] In a preferred embodiment, i) at least one type of solid inorganic particle is Li x La y Zr z A w O 12 (wherein - A represents one or more dopants selected from the group consisting of Al, Ga, Nb, Fe, Nd, Pt, Ta, W, Mo, Hf, Si, Ca, Sr, Ba, Ge, and mixtures thereof, preferably selected from the group consisting of Al, Ga, Nb, Fe, Nd, Pt, Ta, W, and mixtures thereof, more preferably selected from the group consisting of Al, Ga, W, and mixtures thereof; - w, x, y, and z are positive numbers including various combinations of integers and fractions or decimals; - 0 < y ≤ 3; preferably 2 ≤ y ≤ 3; preferably 2.5 ≤ y ≤ 3; - 0 < z ≤ 2; preferably 1 ≤ z ≤ 2; preferably 1.5 ≤ z ≤ 2; - 0 ≤ w ≤ 0.5; preferably 0 ≤ w ≤ 0.35; more preferably 0 ≤ w ≤ 0.25; and - x is derived from the electrical neutrality of the garnet structure) has the general formula of

[0033] In a preferred embodiment, i) at least one type of solid inorganic particle is LLZO. As used herein, the term "LLZO" refers to Li x L 3y Zr z A W O 12 having the general formula, where x, y, x, w, and A are as described above. According to a preferred embodiment, i) at least one type of solid inorganic particle is LLZO doped with Al, W, Ga, or a combination thereof.

[0034] The general formulas given in this application correspond to the stoichiometry of the crystal structure given by X-ray diffraction (XRD).

[0035] LLZO can be prepared according to standard procedures known from the prior art, for example, in Inorg. Chem., 2015, 54, 3600-3607 and Angew. Chem. Int. Ed. 2007, 46, 7778-7781. For example, LLZO can typically be prepared by solid-state reactions, which are described in detail in the literature. Precursors such as oxides, carbonates, hydroxides, oxyhydroxides, or nitrates can be used. Stoichiometric amounts of precursors are dried and mixed in a ball mill. To compensate for the loss of volatile lithium during calcination, a slight excess of Li (typically 10-30 mol%) can be added to the starting materials. Successive calcinations are performed at temperatures above 900°C, with intermediate ball milling between each calcination step to obtain LLZO. A typical calcination sequence is, for example, 12 hours at 900°C and 12 hours at 1100°C.

[0036] According to one embodiment, i) the amount of the at least one type of solid inorganic particles is 60.0 to 98.0 wt %, preferably 70.0 to 95.0 wt %, more preferably 80.0 to 92.0 wt %, based on the total weight of the solid composite electrolyte.

[0037] ionic liquids As used herein, the term "ionic liquid" refers to a compound that contains positively charged cations and negatively charged anions and that is in a liquid state at atmospheric pressure and temperatures below 100°C. While ordinary liquids such as water are made up primarily of electrically neutral molecules, ionic liquids are made up primarily of ions and short-lived ion pairs. As used herein, the term "ionic liquid" refers to a compound that does not contain a solvent.

[0038] As used herein, the term "cationic atom" refers to at least one non-metallic atom that carries a positive charge.

[0039] As used herein, the term "onium cation" refers to a positively charged ion with at least a portion of its charge localized on at least one non-metallic atom such as O, N, S, or P.

[0040] In the present invention, the ionic liquid is A n- Q l+ (n / l) (In the formula, -A n- represents an anion; - Q l+ (n / l) represents a cation; n and l are independently selected from 1 to 5, and each represents an anion A n- and cation Q l+ (n / l) represents the charge of It has the general formula:

[0041] The cations may be selected independently from metal cations and organic cations. The cations may be monovalent or polyvalent cations.

[0042] Preferred examples of the metal cation include alkali metal cations, alkaline earth metal cations, and cations of d-block elements.

[0043] In the present invention, Q l+ (n / l) may represent an onium cation. An onium cation is a cation formed by elements of groups VB and VIB (as defined in the old European IUPAC system according to the periodic table of the elements) having three or four hydrocarbon chains. Group VB includes N, P, As, Sb, and Bi atoms. Group VIB includes O, S, Se, Te, and Po atoms. The onium cation may in particular be a cation formed by an atom selected from the group consisting of N, P, O, and S, more preferably N and P, and three or four hydrocarbon chains.

[0044] Onium Cation Ql+ (n / l) teeth, heterocyclic onium cations; in particular those selected from the group consisting of: TIFF0007805166000001.tif73170- Unsaturated cyclic onium cations; in particular those selected from the group consisting of: TIFF0007805166000002.tif32170- saturated cyclic onium cations; in particular those selected from the group consisting of: TIFF0007805166000003.tif122170- Acyclic onium cations; especially those of the general formula + L-R' s (wherein L represents an atom selected from the group consisting of N, P, O and S, more preferably N and P; s represents the number of R′ groups selected from 2, 3 or 4 depending on the valence of the element L, each R′ independently representing a hydrogen atom or a C1-C8 alkyl group; and L + and R' may be a single or double bond) You can choose from:

[0045] In the above formula, each "R" symbol independently represents a hydrogen atom or an organic group. Preferably, each "R" symbol in the above formula independently represents a hydrogen atom or a saturated or unsaturated, linear, branched or cyclic C1-C alkoxy group, which may be optionally substituted one or more times with a halogen atom, an amino group, an imino group, an amide group, an ether group, an ester group, a hydroxyl group, a carboxyl group, a carbamoyl group, a cyano group, a sulfonic acid group or a sulfite group. 18 It may represent a hydrocarbon group.

[0046] Cation Q l+ (n / l) may more particularly be selected from ammonium, phosphonium, pyridinium, pyrrolidinium, pyrazolinium, imidazolium, arsenic, quaternary ammonium and quaternary phosphonium cations.

[0047] The quaternary ammonium or quaternary phosphonium cation can more preferably be selected from tetraalkylammonium or tetraalkylphosphonium cations, trialkylbenzylammonium or trialkylbenzylphosphonium cations, or tetraarylammonium or tetraarylphosphonium cations, in which the alkyl groups are the same or different and represent a linear or branched alkyl chain having 4 to 12 carbon atoms, preferably 4 to 6 carbon atoms, and the aryl groups are the same or different and represent a phenyl or naphthyl group.

[0048] In certain embodiments, Q l+ (n / l) represents a quaternary phosphonium or quaternary ammonium cation.

[0049] In a preferred embodiment, Q l+ (n / l) represents a quaternary phosphonium cation. Non-limiting examples of quaternary phosphonium cations include trihexyl(tetradecyl)phosphonium and tetraalkylphosphonium cations, particularly tetrabutylphosphonium (PBu4) cation.

[0050] In another embodiment, Q l+ (n / l) represents an imidazolium cation. Non-limiting examples of imidazolium cations include 1,3-dimethylimidazolium, 1-(4-sulfobutyl)-3-methylimidazolium, 1-allyl-3H-imidazolium, 1-butyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-octyl-3-methylimidazolium.

[0051] In another embodiment, Q l+ (n / l)are, in particular, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, trimethylbenzylammonium, methyltributylammonium, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium, N,N-dimethyl-N-ethyl-N-(3-methoxypropyl)ammonium, N,N-dimethyl-N-ethyl-N-benzylammonium, N,N-dimethyl-N-ethyl-N-phenylethylammonium, N-tributyl-N-methylammonium, N-trimethyl-N-butylammonium, N-trimethyl-N-hexylammonium, N-trimethyl-N-propylammonium and Aliquat 336 (methyltri(C8-C 10 represents a quaternary ammonium cation selected from the group consisting of (a mixture of alkyl) ammonium compounds.

[0052] In one embodiment, Q l+ (n / l) represents a piperidinium cation, particularly N-butyl-N-methylpiperidinium, N-propyl-N-methylpiperidinium.

[0053] In another embodiment, Q l+ (n / l) represents a pyridinium cation, especially N-methylpyridinium.

[0054] In a more preferred embodiment, Q l+ (n / l) represents a pyrrolidinium cation. Among the specific pyrrolidinium cations, the following may be mentioned: 1~12 Alkyl-C 1~12 Alkyl-pyrrolidinium, more preferably C 1~4 Alkyl-C 1~4Alkyl-pyrrolidinium. Examples of pyrrolidinium cations include, but are not limited to, N,N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium, N-isopropyl-N-methylpyrrolidinium, N-methyl-N-propylpyrrolidinium, N-butyl-N-methylpyrrolidinium, N-octyl-N-methylpyrrolidinium, N-benzyl-N-methylpyrrolidinium, N-cyclohexylmethyl-N-methylpyrrolidinium, and N-[(2-hydroxy)ethyl]-N-methylpyrrolidinium. More preferred are N-methyl-N-propylpyrrolidinium (PYR13) and N-butyl-N-methylpyrrolidinium (PYR14).

[0055] Non-limiting examples of anions of ionic liquids include iodide, bromide, chloride, hydrogen sulfate, dicyanamide, acetate, diethyl phosphate, methyl phosphate, fluorinated anions such as hexafluorophosphate (PF6 - ) and tetrafluoroborate (BF4 - ) and the following formula: Contains oxaloborate from TIFF0007805166000004.tif54170.

[0056] In one embodiment, A n- is a fluorinated anion. Among the fluorinated anions that can be used in the present invention, fluorinated sulfonimide anions can be particularly advantageous. This organic anion is in particular an anion of the following general formula: (Ea-SO2)N - R (In the formula, Ea represents a fluorine atom or a group having preferably 1 to 10 carbon atoms selected from fluoroalkyl, perfluoroalkyl and fluoroalkenyl, and - R represents a substituent. The anion may be selected from the anions having the formula:

[0057] Preferably, Ea may represent F or CF3.

[0058] According to a first embodiment, R represents a hydrogen atom.

[0059] According to a second embodiment, R preferably represents a linear or branched, cyclic or acyclic hydrocarbon-based group having 1 to 10 carbon atoms, optionally having one or more unsaturations, and optionally substituted one or more times with halogen atoms, a nitrile functional group, or an alkyl group optionally substituted one or more times with halogen atoms. Furthermore, R may represent a nitrile group -CN.

[0060] According to a third embodiment, R represents a sulfinate group. In particular, R may represent the group -SO2-Ea, where Ea is as defined above. In this case, the fluorinated anion may be symmetric, i.e., the two Ea groups of the anion are identical, or asymmetric, i.e., the two Ea groups of the anion are different.

[0061] Furthermore, R may represent the group -SO2-R', where R' preferably represents a linear or branched, cyclic or acyclic hydrocarbon-based group having 1 to 10 carbon atoms and optionally having one or more unsaturations and optionally substituted one or more times with halogen atoms, a nitrile functional group, or an alkyl group optionally substituted one or more times with halogen atoms. In particular, R' may comprise a vinyl or allyl group. Furthermore, R may represent the group -SO2-N-R', where R' is as defined above or alternatively R' represents a sulfonate functional group -SO3-.

[0062] The cyclic hydrocarbon group may preferably refer to a cycloalkyl group or an aryl group. "Cycloalkyl" refers to a monocyclic hydrocarbon chain having 3 to 8 carbon atoms. Preferred examples of a cycloalkyl group are cyclopentyl and cyclohexyl. "Aryl" refers to a monocyclic or polycyclic aromatic hydrocarbon group having 6 to 20 carbon atoms. Preferred examples of an aryl group are phenyl and naphthyl. When the group is a polycyclic group, the rings may be fused or bonded by a σ (sigma) bond.

[0063] According to a fourth embodiment, R represents a carbonyl group. R may in particular be represented by the formula -CO-R', where R' is as defined above.

[0064] The organic anion that can be used in the present invention is advantageously CF3SO2N - SO2CF3 (bis(trifluoromethanesulfonyl)imide anion, commonly designated as TFSI), FSO2N - SO2F (bis(fluorosulfonyl)imide anion, commonly referred to as FSI), CF3SO2N - SO2F and CF3SO2N - SO2N - It can be selected from the group consisting of SO2CF3.

[0065] In a preferred embodiment, the ionic liquid is - One or more C1 to C 30 a positively charged cation selected from the group consisting of imidazolium, pyridinium, pyrrolidinium, and piperidinium ions, optionally containing alkyl groups; a negatively charged anion selected from the group consisting of halides, fluorinated anions and borates; Contains:

[0066] C1~C 30 Non-limiting examples of alkyl groups include, among others, methyl, ethyl, propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, 2,2-dimethyl-propyl, hexyl, 2,3-dimethyl-2-butyl, heptyl, 2,2-dimethyl-3-pentyl, 2-methyl-2-hexyl, octyl, 4-methyl-3-heptyl, nonyl, decyl, undecyl, and dodecyl groups.

[0067] In the present invention, ii) the at least one ionic liquid electrolyte comprises at least one ionic liquid and at least one lithium salt.

[0068] In the present invention, when i) at least one type of solid inorganic particle is blended with ii) at least one type of ionic liquid electrolyte, ii) at least a portion of the ionic liquid electrolyte covers at least a portion of the surface of i) the solid inorganic particle.

[0069] lithium salts Lithium salts include lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluoroantimonate (LiSbF6), lithium hexafluorotantalate (LiTaF6), lithium tetrachloroaluminate (LiAlCl4), lithium tetrafluoroborate (LiBF4), and lithium chloroborate (Li2B 10 Cl 10 ), lithium fluoroborate (Li2B 10 F 10 ), Li2B 12 F x H 12-x (x=0~12); LiPF x (R F ) 6-x and LiBF y (R F ) 4-y (In the formula, R F Perfluorinated C1-C 20 represents an alkyl group or a perfluorinated aromatic group, x=0-5, and y=0-3), LiBF2[O2C(CX2) n CO2], LiPF2[O2C(CX2) n CO2]2, LiPF4[O2C(CX2) n CO2] (wherein X is selected from the group consisting of H, F, Cl, C1-C4 alkyl groups and fluorinated alkyl groups, and n = 0-4), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(fluorosulfonyl)imide Li(FSO2)2N (LiFSI), LiN(SO2C m F 2m+1 )(SO2C n F 2n+1 ) and LiC(SO2C k F 2k+1 )(SO2C m F2m+1 )(SO2C n F 2n+1 ) (wherein k=1 to 10, m=1 to 10, and n=1 to 10), LiN(SO2C p F 2p SO2) and LiC(SO2C p F 2p SO2)(SO2C q F 2q+1 ) (wherein p=1 to 10 and q=1 to 10), lithium salts of chelated orthoborates and chelated orthophosphates, such as lithium bis(oxalato)borate [LiB(C2O4)2], lithium bis(malonato)borate [LiB(OCCH2CO2)2], lithium bis(difluoromalonato)borate [LiB(OCCF2CO2)2], lithium (malonatooxalato)borate [LiB(C2O4)(OCCH2CO2)], Lithium ion complexes such as lithium (difluoromalonatooxalato)borate [LiB(C2O4)(O2CCF2CO2)], lithium tris(oxalato)phosphate [LiP(C2O4)3], lithium tris(difluoromalonato)phosphate [LiP(O2CCF2CO2)3], lithium difluorophosphate (LiPO2F2), lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI), as well as mixtures of the foregoing, are described.

[0070] Preferred lithium salts are lithium hexafluorophosphate (LiPF), lithium bis(fluorosulfonyl)imide Li(FSO)N (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI), LiBF, LiB(C0), LiAsF, LiClO, LiNO, lithium bis(oxalato)borate, LiCFSO, LiN(SOCF) (LiTFSI), LiN(SOCF), LiC(SOCF), LiN(SOCF), LiCFSO, LiCF 93 SO 3,LiAlCl4, LiSbF6, LiF, LiBr, LiCl, LiOH, LiPFSi and lithium trifluoromethanesulfonate.

[0071] More preferred lithium salts are lithium hexafluorophosphate (LiPF), lithium bis(fluorosulfonyl)imide LiN(SOCF) (LiTFSI), and lithium bis(fluorosulfonyl)imide Li(FSO)N (LiFSI), which may be used alone or in combination.

[0072] The concentration of the lithium salt is typically in the range of 0.1 to 3.0 moles per liter, preferably 0.15 to 2.0 moles per liter, and more preferably 0.2 to 1.0 moles per liter of ionic liquid electrolyte.

[0073] According to one embodiment, ii) the amount of the at least one ionic liquid electrolyte is 1.0 to 30.0 wt %, preferably 3.0 to 25.0 wt %, more preferably 5 to 20 wt %, and even more preferably 5 to 15 wt %, based on the total weight of the solid composite electrolyte.

[0074] Non-ionic conductive polymer Binders help hold the active materials in the electrodes of lithium-ion batteries. Such binder materials are usually inert and play an important role in battery fabrication. An ideal binder material is expected to form an excellent network between the active materials and conductive additives, which is stable and facilitates electronic and ionic transport.

[0075] Numerous binder materials are known in the art, among which fluoropolymers are known in the art to be suitable for the manufacture of various components for use in electrochemical devices such as lithium-ion batteries. In particular, vinylidene fluoride (VDF) (co)polymers have been found to have excellent electrochemical stability and high adhesion to electrode materials and current collectors.

[0076] In the present invention, the polymer is non-ionically conductive.

[0077] Non-limiting examples of non-ionically conductive polymers include, among others, VDF (co)polymers, styrene-butadiene rubber (SBR), styrene-ethylene-butylene-styrene (SEBS), carboxymethyl cellulose (CMC), polyamideimide (PAI), perfluoroalkoxyalkanes (PFA) and (co)polymers of poly(tetrafluoroethylene) (PTFE) and poly(acrylonitrile) (PAN).

[0078] VDF (co)polymer Polyvinylidene fluoride (PVDF or VDF polymer) is one of the most widely used fluoropolymers in battery components due to its high anode and cathode stability, bond strength and adhesion to current collectors.

[0079] In one embodiment, the non-ion-conducting polymer according to the present invention is a VDF (co)polymer. In the present invention, a VDF polymer refers to a polymer consisting essentially of repeating units, more than 85 mol % of said repeating units being derived from VDF.

[0080] The VDF polymer is preferably (a) at least 85 mol % of repeat units derived from VDF; (b) optionally, 0.1 to 15 mol %, preferably 0.1 to 12 mol %, more preferably 0.1 to 10 mol % of repeat units derived from a fluorinated monomer other than VDF; (c) optionally, 0.1 to 5 mol %, preferably 0.1 to 3 mol %, more preferably 0.1 to 1 mol % of repeating units derived from one or more hydrogen-containing comonomers; and all of the foregoing mole percentages are based on the total moles of repeat units of the VDF polymer.

[0081] Non-limiting examples of suitable fluorinated monomers different from VDF include, in particular: - C2-C8 perfluoroolefins such as tetrafluoroethylene and hexafluoropropylene (HFP); - C2-C8 hydrogen-containing fluoroolefins such as vinyl fluoride, 1,2-difluoroethylene and trifluoroethylene; - Formula CH2=CH-R f0 (In the formula, R f0 is a C1-C6 perfluoroalkyl) perfluoroalkylethylene, - chloro- and / or bromo- and / or iodo-C2-C6 fluoroolefins, such as chlorotrifluoroethylene; - Formula CF2=CFOR f1 (In the formula, R f1 is C1-C6 fluoro- or perfluoroalkyl, for example, CF3, C2F5, C3F7), (per)fluoroalkyl vinyl ethers; CF2=CFOX0(per)fluoro-oxyalkyl vinyl ether (wherein X0 is C1-C 12 Alkyl groups, C1-C 12 C1-C with one or more ether groups, such as oxyalkyl groups or perfluoro-2-propoxy-propyl groups 12 (per)fluorooxyalkyl groups); - Formula CF2=CFOCF2OR f2 (In the formula, R f2 is a C1-C6 fluoro- or perfluoroalkyl group, for example a C1-C6 (per)fluorooxyalkyl group having one or more ether groups, such as CF3, C2F5, C3F7 or -C2F5-O-CF3; (per)fluoroalkyl vinyl ethers of the formula: Formula CF2 = CFOY0 (wherein Y0 is C1 to C 12 Alkyl group or (per)fluoroalkyl group, C1-C 12 C1-C having an oxyalkyl group or one or more ether groups 12 a (per)fluorooxyalkyl group, and Y0 comprises a carboxylic or sulfonic acid group in the form of its acid, acid halide or salt); Fluorodioxoles, preferably perfluorodioxoles.

[0082] In a preferred embodiment, the (b) fluorinated monomer is advantageously selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene (CTFE), 1,2-difluoroethylene, tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro(alkyl)vinyl ethers (such as perfluoro(methyl)vinyl ether (PMVE), perfluoro(ethyl)vinyl ether (PEVE) and perfluoro(propyl)vinyl ether (PPVE)), perfluoro(1,3-dioxole), and perfluoro(2,2-dimethyl-1,3-dioxole) (PDD). Preferably, the possible additional fluorinated monomer is selected from the group consisting of chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), trifluoroethylene (TrFE) and tetrafluoroethylene (TFE).

[0083] Various copolymers of VDF have been investigated to further improve performance, and non-limiting examples of VDF (co)polymers useful in the present invention include, inter alia, VDF homopolymer, VDF / TFE copolymer, VDF / TFE / HFP copolymer, VDF / TFE / CTFE copolymer, VDF / TFE / TrFE copolymer, VDF / CTFE copolymer, VDF / HFP copolymer, VDF / TFE / HFP / CTFE copolymer, etc.

[0084] The hydrogenated comonomer is not particularly limited, and can be an α-olefin, a (meth)acrylic monomer, a vinyl ether monomer, or a styrene monomer. Nevertheless, in one embodiment, in order to optimize chemical resistance, a VDF polymer that is essentially free of repeating units derived from the hydrogenated comonomer is preferred.

[0085] Therefore, the VDF polymer is more preferably (a) at least 85 mol % of repeat units derived from VDF; (b) optionally, 0.1 to 15 mol %, preferably 0.1 to 12 mol %, more preferably 0.1 to 10 mol % of a fluorinated monomer different from VDF (the fluorinated monomer is preferably selected from vinyl fluoride, chlorotrifluoroethylene (CTFE), hexafluoropropene (HFP), tetrafluoroethylene (TFE), perfluoromethyl vinyl ether (MVE), trifluoroethylene (TrFE) and mixtures thereof); All of the foregoing mole percentages are based on the total moles of repeat units in the VDF polymer.

[0086] In addition to the repeating units, defects, end chains, impurities, chain inversions or branches, etc. may also be present in the VDF polymer, without these constituents substantially modifying the behavior and properties of the VDF polymer.

[0087] In one embodiment according to the present invention, VDF homopolymer is particularly advantageous for use as the non-ion-conducting polymer in the solid composite electrolyte.

[0088] In another particular embodiment according to the invention, the copolymer of VDF is a copolymer of VDF monomers with the following formula: TIFF0007805166000005.tif28170 (wherein R1, R2, and R3 are the same or different from one another and independently represent a hydrogen atom or a C1-C3 hydrocarbon group, and ROH represents hydrogen or a C1-C5 hydrocarbon moiety containing at least one hydroxyl group) and at least one hydrophilic (meth)acrylic monomer, and said copolymer of VDF contains 0.05 to 10 mol % of repeating units derived from said hydrophilic (meth)acrylic monomer (MA), which is characterized by a fraction of randomly distributed units (MA) of at least 40%.

[0089] Non-limiting examples of hydrophilic (meth)acrylic monomers (MA) are in particular acrylic acid, methacrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate; hydroxyethylhexyl (meth)acrylate.

[0090] The monomer (MA) is more preferably - Hydroxyethyl acrylate (HEA) of the following formula: TIFF0007805166000006.tif28170- 2-Hydroxypropyl acrylate (HPA) of any of the following formulas: TIFF0007805166000007.tif34170- Acrylic acid (AA) of the following formula: TIFF0007805166000008.tif29170; and - A mixture of these is selected from the group consisting of:

[0091] Most preferably, the monomers are AA and / or HEA.

[0092] In a preferred embodiment, the non-ion-conducting polymer is a VDF / AA copolymer.

[0093] styrene-based block copolymer In one embodiment, the non-ion-conducting polymer according to the present invention is a styrenic block copolymer consisting of a polystyrene block and a rubber block. The rubber block consists essentially of polybutadiene, polyisoprene, or their hydrogenated equivalents. Non-limiting examples of styrenic block copolymers include SBR (styrene butadiene rubber) and its selectively hydrogenated rubber, i.e., SEBS (styrene-ethylene-butylene-styrene). SBR also includes high-styrene rubbers having a high styrene content and a high glass transition temperature (Tg). Furthermore, in the present invention, SBR includes modified SBR copolymerized with an unsaturated carboxylic acid or an unsaturated nitrile compound. These types of SBR have slightly different physical properties (e.g., adhesion, strength, thermal properties) due to the copolymerization type and the styrene / butadiene copolymerization ratio.

[0094] In one embodiment, the non-ion-conducting polymer according to the present invention is SEBS (styrene-ethylene-butylene-styrene).

[0095] CMC In one embodiment, the non-ion-conducting polymer according to the present invention is a cellulosic material, including but not limited to carboxymethyl cellulose (CMC), diacetyl cellulose, hydroxypropyl cellulose, and methylhydroxypropyl cellulose. In a preferred embodiment, the non-ion-conducting polymer according to the present invention is CMC.

[0096] PAI In one embodiment, the non-ion-conducting polymer according to the present invention is polyamideimide (PAI). PAIs are amorphous thermoset or thermoplastic polymers with excellent mechanical, thermal, and chemical resistance. PAIs exhibit a combination of properties of both polyamides and polyimides, including high strength, melt processability, exceptionally high heat capacity, and broad chemical resistance.

[0097] In the present invention, the PAI comprises repeating units, more than 50 mole percent of which comprise at least one aromatic ring and at least one amic acid group and / or imide group, and more than 50 mole percent of which comprise at least one amic acid group, some or all of which are neutralized with at least one basic compound.

[0098] The repeating unit is advantageously TIFF0007805166000009.tif107170TIFF0007805166000010.tif69170 (in the formula, - the notation "→" denotes isomerism in which the group pointed to by the arrow can exist as shown or in an interchangeable position in any repeat unit within the aromatic polyamic acid structure; "Ar" means an aromatic tetravalent radical, which may contain one or more aromatic rings, preferably TIFF0007805166000011.tif46170 (wherein X is selected from the group consisting of -O-, -C(O)-, -S-, -SO2-, -CH2-, -C(CF3)2-, and -(CF2)n- (wherein n=0, 1, 2, 3, 4, or 5)) selected from the group consisting of: R is an aromatic divalent group, which may contain one or more aromatic rings; TIFF0007805166000012.tif49170 (wherein Y is -O-, -C(O)-, -S-, -SO2-, -CH2-, -C(CF3)2-, or -(CF2)n- (wherein n=0, 1, 2, 3, 4, or 5)), TIFF0007805166000013.tif37170) is selected from.

[0099] Suitable basic compounds are, in particular, those capable of neutralizing the amic acid groups of the repeating units of the PAI. Inorganic and organic bases can be used to neutralize some or all of the amic acid groups in the PAI.

[0100] Non-limiting examples of inorganic bases include alkali and alkaline earth metal hydroxides such as NaOH, KOH, Mg(OH)2, ammonia, among others.

[0101] Non-limiting examples of organic bases are organic amines, such as aliphatic, aromatic, heterocyclic or heteroaromatic amines, among others.

[0102] Preferably, the basic compound is a tertiary amine. The tertiary amine may be, in particular, a tri-(C1-C4 alkyl)amine, such as trimethylamine, N,N-dimethylethylamine, N,N-dimethylpropylamine, triethylamine, or tributylamine. Cyclic tertiary amines may also be found useful. Tertiary alkanolamines such as N,N-dimethylethanolamine, N-butyldiethanolamine, diethyl-2-hydroxyethylamine, and the like may also be used. Aromatic amines such as N,N-dimethylaniline, pyridine, and N-methylpyrrole may also be used. While polyfunctional amines such as N,N'-dimethylpiperidine and N,N,N',N'-tetraalkyl-alkali diamines and poly-N-alkylated alkylene triamines may also be found effective, polyfunctional amines are less preferred due to their potential tendency to form associative crosslinks and gels.

[0103] The most preferred basic compounds are selected from the group consisting of N,N-dimethylethanolamine, N-butyldiethanolamine, diethyl-2-hydroxyethylamine, and mixtures thereof.

[0104] PFA In one embodiment, the non-ion-conducting polymer according to the present invention is a perfluoroalkoxyalkane (PFA). PFA is a copolymer of tetrafluoroethylene and a perfluoroether, said perfluoroether being C2F3OR f where R f is a perfluoro group such as trifluoromethyl (CF). In certain such embodiments, the PFA has the following formula: It has TIFF0007805166000014.tif51170.

[0105] PTFE In one embodiment, the non-ion-conducting polymer according to the present invention is a tetrafluoroethylene (TFE) polymer or TFE copolymer having one or more perfluorinated comonomers. Suitable comonomers include: - C3-C8 perfluoroolefins, such as hexafluoropropene (HFP) and hexafluoroisobutene; - CF2=CFOR f Perfluoroalkyl vinyl ether (PAVE) (wherein R f is C1-C6 perfluoroalkyl, for example -CF3, -C2F5 or -C3F7; CF2 = CFOX perfluorooxyalkyl vinyl ether (wherein X is a C1-C alkyl group having one or more ether groups). 12 perfluoroalkyl); and - Perfluorodioxole Examples include:

[0106] Preferably, the comonomer is one of the following comonomers: - Formula CF2=CFOR f1 PAVE (wherein R f1 is selected from -CF3, -C2F5 and -C3F7), namely perfluoromethyl vinyl ether (PMVE of formula CF2 = CFOCF3), perfluoroethyl vinyl ether (PEVE of formula CF2 = CFOC2F5), perfluoropropyl vinyl ether (PPVE of formula CF2 = CFOC3F7) and mixtures thereof; - General formula CF2=CFOCF2OR f2 perfluoromethoxyvinyl ether (MOVE) (wherein R f2 is a linear or branched C1 to C6 perfluoroalkyl group, a cyclic C5 to C6 perfluoroalkyl group, or a linear or branched C2 to C6 perfluorooxyalkyl group; preferably, R f2is -CF2CF3(MOVE1), -CF2CF2OCF3(MOVE2) or -CF3(MOVE3); and - the following formula: TIFF0007805166000015.tif33170 (wherein X1 and X2 are equal to or different from each other and are selected from F and CF3, preferably F). Perfluorodioxole having is selected from.

[0107] Non-limiting examples of perfluorodioxoles as suitable perfluorinated comonomers include: Contains TIFF0007805166000016.tif71170.

[0108] In terms of properties, PFA and PTFE are similar fluoropolymers. The major difference between them is that the alkoxy substituents in PFA make the polymer melt-processible. At the molecular level, PFA has shorter chain lengths and greater chain entanglements than other fluoropolymers. It also contains oxygen atoms in the branches, resulting in properties that approach or exceed those of PTFE, such as greater translucency and improved flow and thermal stability.

[0109] PAN In one embodiment, the non-ion-conducting polymer according to the present invention is PAN (polyacrylonitrile). Most PAN polymers are copolymers made from a mixture of monomers with acrylonitrile as the predominant monomer. Non-limiting examples of PAN copolymers include styrene-acrylonitrile (SAN) copolymer, poly(acrylonitrile-co-methyl acrylate) (PAN-MA), and acrylonitrile butadiene styrene (ABS) copolymer.

[0110] PAO In one embodiment, the non-ionically conductive polymer according to the present invention is a PAO (polyalkylene oxide) polymer or copolymer. PAOs have the general formula H-(OR)-OH, where R preferably represents an alkylene group having 1 to 20, more preferably 2 to 12, carbon atoms. The best-known polyalkylene oxide is polyethylene oxide (PEO), also commonly called polyethylene glycol (PEG), which is the preferred polyalkylene oxide for the process of the present invention.

[0111] In the present invention, additives may additionally be present in the solid composite electrolyte. Examples of other additives include, but are not limited to, cathode protectants, LiPF6 salt stabilizers, safety protectants, dispersants, Li adhesion improvers, ion salvation promoters, Al corrosion inhibitors, wetting agents, viscosity thinners, swelling inhibitors, and low- or high-temperature performance enhancers. According to one embodiment, the amount of iii) at least one non-ion-conducting polymer is 1.0 to 10.0 wt %, preferably 2.0 to 5.0 wt %, and more preferably 3.0 to 5.0 wt %, based on the total weight of the solid composite electrolyte.

[0112] According to one embodiment, the solid composite electrolyte comprises, based on the total weight of the solid composite electrolyte: - 60.0 to 98.0% by weight of i) at least one solid inorganic particle; - 1.0 to 30.0 wt. % of ii) at least one ionic liquid electrolyte; 1.0 to 10.0 wt. % of iii) at least one non-ionically conductive polymer Includes:

[0113] According to one preferred embodiment, the solid composite electrolyte comprises, based on the total weight of the solid composite electrolyte: - 75.0 to 95.0% by weight of i) at least one solid inorganic particle; 3.0 to 20.0 wt. % of ii) at least one ionic liquid electrolyte; and 2.0 to 5.0% by weight of iii) at least one non-ionically conductive polymer Includes:

[0114] According to another preferred embodiment, the solid composite electrolyte comprises, based on the total weight of the solid composite electrolyte: - 80.0 to 92.0% by weight of i) at least one solid inorganic particle; 5.0 to 20.0 wt. % of ii) at least one ionic liquid electrolyte; and 3.0 to 5.0% by weight of iii) at least one non-ionically conductive polymer Includes:

[0115] A second object of the present invention is a method for producing the solid composite electrolyte detailed above.

[0116] In one embodiment, the method according to the present invention comprises the steps of: - blending i) at least one solid inorganic particle with ii) at least one ionic liquid electrolyte; - iii) preparing a polymer solution of at least one non-ion-conducting polymer; - mixing the blended solid inorganic particles with a polymer solution; - casting the resulting solid composite electrolyte onto a substrate to form a wet membrane; - drying the wet film; and - Calendaring the membrane Includes:

[0117] In another embodiment, the method according to the present invention comprises the steps of: - blending i) at least one solid inorganic particle with ii) at least one ionic liquid electrolyte; - mixing the blended solid inorganic particles with iii) at least one non-ionically conductive polymer to obtain a viscous paste; and - Calendering or extrusion of the viscous paste in successive steps to obtain a solid, uniform film and iii) the at least one non-ion-conducting polymer is in a dry state.

[0118] In another embodiment, the method according to the present invention comprises the steps of: - blending i) at least one solid inorganic particle with ii) at least one ionic liquid electrolyte; - mixing said blended solid inorganic particles with iii) at least one non-ionically conductive polymer to obtain a dry powder; - powder coating the dry powder; and - Annealing the deposited powder to obtain a film Includes:

[0119] A third object of the present invention is a solid-state battery comprising the above-mentioned solid composite electrolyte. The solid composite electrolyte according to the present invention can be used to prepare an electrode, an intermediate layer or a separator of a solid-state battery.

[0120] A fourth object of the present invention is the use of the above-mentioned solid composite electrolyte to improve ionic conductivity and mechanical properties.

[0121] Mechanical properties can be assessed visually by determining whether the membrane i) is self-supporting, ii) is flexible, i.e., can be repeatedly bent without breaking or crack formation, and iii) is mechanically resistant to deformation, which means it must be able to withstand the physical stresses of the pressing / calendering process, which would reduce the membrane's porosity, and must be compatible with roll-to-roll or stacking processes.

[0122] To the extent that the disclosure of any patents, patent applications, and publications incorporated herein by reference contradicts the statements of this application to the extent that the term may be unclear, the statements of this application shall control.

[0123] The present invention will now be described with reference to the following examples, the purposes of which are merely illustrative and are not intended to limit the scope of the invention. [Example]

[0124] raw materials Solid inorganic particles: nominal composition Li doped with W 6.3 La3Zr 1.65 W 0.35 O 12 W-doped LLZO particles were obtained according to the procedure disclosed in Inorg. Chem., 2015, 54, 3600-3607.

[0125] Ionic liquid electrolyte (ILE): LiTFSI / PYR14TFSI, available from Solvay.

[0126] Non-ion conducting polymer: Solef® 5130 (PVDF-AA copolymer, available from Solvay Specialty Polymers Italy SpA): Ex.1, Ex.2, Ex.4, Ex.5, Ex.6, Ex.7 and Comp.Ex.1; Solef® 21216 (PVDF-HFP copolymer, also available from Solvay Specialty Polymers Italy SpA): Ex. 3. · Tuftec™ N504 (styrene-ethylene-butylene-styrene copolymer; available from Asahi Kasei): Ex. 8.

[0127] Preparation Examples Example 1 (Ex. 1) The ionic liquid electrolyte was prepared as follows: Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) at a concentration of 5 wt % to produce the ionic liquid electrolyte. The same ionic liquid electrolyte was used in the following examples.

[0128] LLZO was then blended with an ionic liquid containing a Li salt. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) at a concentration of 5 wt% LiTFSI. Subsequently, 4.6 g of W-doped LLZO was mixed with 0.25 g of ionic liquid electrolyte in a planetary mixer (Speed ​​Mixer DAC 400.1 FVZ; 2 min @ 2000 rpm). The blended LLZO powder was mixed into a PVDF solution (Solef® 5130; 5 wt% in NMP), cast onto a polymer substrate using an electric film applicator, and dried at 80°C under vacuum. The resulting free-standing membrane was finally calendered at 80°C using a Precision 4" Hot Rolling Press / Calender (MSK-HRP-01, supplied by MTI). The membrane was calendered until no further change in thickness was obtained.

[0129] Examples 2 to 8 (Ex. 2 to 8) Ex.2 and Ex.4 to Ex.7 were each prepared in the same manner as Ex.1, except that the amount of ionic liquid electrolyte was different.

[0130] Ex.3 was prepared in the same manner as Ex.1, except that the amount of ionic liquid electrolyte was different and PVDF-HFP copolymer was used instead of PVDF-AA copolymer.

[0131] Ex.8 was also prepared in the same manner as Ex.1, except that the amount of ionic liquid electrolyte was different and styrene-ethylene-butylene-styrene was used instead of PVDF-AA copolymer.

[0132] Comparative example 1 (Comp.Ex.1) Six grams of W-doped LLZO (the same as in Example 1) was mixed with 0.15 g of additive, 3 ml of DMF, and 3 mm zirconia beads in a three-dimensional shaker / mixer (Turbula T2F) for 16 hours. The homogenized product was then mixed with a PVDF-LiTFSI solution (0.3 g of PVDF-AA copolymer, 0.12 g of LiTFSI, and 9 g of DMF), cast onto an ECTFE (ethylene chlorotrifluoroethylene) substrate, and dried under vacuum at 80°C. This resulted in a highly filled ceramic membrane with 93.6 wt% LLZO (containing 2.3 wt% of another additive). This was dispersed in 4.5 wt% PVDF containing 1.9 wt% LiTFSI as the Li salt. Finally, the resulting free-standing membrane was calendered at 80°C.

[0133] Comparative Example 2: Five grams of W-doped LLZO (the same as used in Example 1) was mixed with 1 gram of ionic liquid electrolyte in a planetary mixer (Speed ​​Mixer DAC400.1 FVZ; 2 minutes at 2000 rpm) to obtain a viscous paste. Although this paste could be formed or pressed into simple shapes (such as disks), it had no self-supporting properties. Therefore, the composition of Comp. Ex. 2 is not practical as a solid composite electrolyte.

[0134] The compositions of all the resulting composite membranes Ex.1-4 and Comp.Ex.1-2 are shown in Table 1 below.

[0135] TIFF0007805166000017.tif106170

[0136] Ionic conductivity measurement The ionic conductivity of the membranes was measured by AC impedance spectroscopy using an in-house developed pressure cell, in which the membrane is pressed between two stainless steel electrodes (55 MPa) during impedance measurements. A cross-sectional view of the pressure cell is shown in Figure 1.

[0137] The resistance R of the solid composite electrolyte membrane was obtained by extrapolating (using a linear model) the quasi-linear portion of the low-frequency diffusion tail of the impedance spectrum. The resistance R was measured at 20 °C and taken as the point where the extrapolated curve intersected the X-axis. Based on this, the ionic conductivity σ was obtained using the formula σ = d / (R × A), where d is the thickness of the membrane and A is the area of ​​the stainless steel electrode.

[0138] The SI unit of ionic conductivity is Siemens per meter (S / m), where S is ohm-1. The results are summarized in Table 2.

[0139] TIFF0007805166000018.tif114170

[0140] As shown in Table 2 above, the membranes obtained according to the present invention (Ex. 1 to 8) exhibited much better ionic conductivity than the membrane from Comp. Ex. 1. In this regard, the hybrid formulation from Comp. Ex. 2 exhibited excellent ionic conductivity due to the presence of a significantly larger amount of ionic liquid electrolyte, but the composition was not self-supporting. On the other hand, all membranes from Ex. 1 to 8 exhibited excellent mechanical properties, which were clearly demonstrated by their self-supporting characteristics without the need for support, and also exhibited excellent flexibility.

Claims

1. i) at least one solid inorganic particle; ii) at least one ionic liquid electrolyte; iii) at least one non-ion-conducting polymer; wherein i) at least one solid inorganic particle is ionically conductive and ii) is blended with at least one ionic liquid electrolyte; The at least one solid inorganic particle is M １ ａ M ２ ｂ M ３ ｃ O ｄ (In the formula, M １ is a first cationic element selected from the group consisting of H, Li, Na, Mg, Al, and Ga; M ２ is a second cationic element selected from the group consisting of La, Ba, Sr, Ca, In, Mg, Y, Sc, Cr, Al, K, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; M ３ is a third cationic element selected from the group consisting of Zr, Ta, Nb, Sb, Sn, Hf, Bi, W, Si, Se, Ga, and Ge; and a, b, c, and d are positive numbers containing various combinations of integers and decimals. garnet-type inorganic particles having the general formula: the amount of the at least one solid inorganic particle is 60.0 to 98.0 weight percent (wt%) based on the total weight of the solid composite electrolyte; Solid composite electrolyte.

2. The at least one solid inorganic particle is Li ｘ La ｙ Zr ｚ A ｗ O １２ (In the formula, A represents one or more dopants selected from the group consisting of Al, Ga, Nb, Fe, Nd, Pt, Ta, W, Mo, Hf, Si, Ca, Sr, Ba, Ge and mixtures thereof; - w, x, y and z are positive numbers including various combinations of integers and fractions or decimals; 0<y≦3; 0<z≦2; 0≦w≦0.5; and - x is derived from the electroneutrality of the garnet structure) 2. The solid composite electrolyte of claim 1 having the general formula:

3. 3. The solid composite electrolyte of claim 2, wherein the garnet-type inorganic particles are doped with Al, W, Ga, or a combination thereof.

4. The solid composite electrolyte according to any one of claims 1 to 3, wherein the ii) at least one ionic liquid electrolyte comprises at least one ionic liquid and at least one Li salt.

5. The ionic liquid is - One or more C １ ~C ３０ a positively charged cation selected from the group consisting of imidazolium, pyridinium, pyrrolidinium, and piperidinium ions, optionally containing alkyl groups; a negatively charged anion selected from the group consisting of halides, fluorinated anions and borates; Including C １ ~C ３０ 5. The solid composite electrolyte of claim 4, wherein the alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, 2,2-dimethyl-propyl, hexyl, 2,3-dimethyl-2-butyl, heptyl, 2,2-dimethyl-3-pentyl, 2-methyl-2-hexyl, octyl, 4-methyl-3-heptyl, nonyl, decyl, undecyl, and dodecyl groups.

6. The Li salt is lithium hexafluorophosphate (LiPF ６ ), lithium bis(fluorosulfonyl)imide Li(FSO ２ ) ２ N (LiFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI), LiBF ４ , LiB(C ２ O ４ ) ２ , LiAsF ６ , LiClO ４ , LiNO ３ , lithium bis(oxalato)borate, LiCF ３ SO ３ , LiN(SO ２ CF ３ ) ２ (LiTFSI), LiN(SO ２ C ２ F ５ ) ２ , LiC(SO ２ CF ３ ) ３ , LiN(SO ３ CF ３ ) ２ , LiC ４ F ９ SO ３ , LiCF ９３ SO ３、 LiAlCl ４ , LiSbF ６ 6. The solid composite electrolyte according to claim 4 or 5, comprising at least one selected from the group consisting of LiF, LiBr, LiCl, LiOH, LiPFSi and lithium trifluoromethanesulfonate.

7. 7. The solid composite electrolyte according to claim 1, wherein the iii) at least one non-ion conducting polymer comprises vinylidene fluoride (VDF) (co)polymer, styrene-butadiene rubber (SBR), styrene-ethylene-butylene-styrene (SEBS), carboxymethyl cellulose (CMC), polyamideimide (PAI), perfluoroalkoxyalkane (PFA), poly(tetrafluoroethylene) (PTFE), poly(acrylonitrile) (PAN) (co)polymer, and polyalkylene oxide (PAO) (co)polymer.

8. 8. The solid composite electrolyte according to claim 1, wherein the amount of ii) the at least one ionic liquid electrolyte is 1.0 to 30.0 wt %, based on the total weight of the solid composite electrolyte.

9. The solid composite electrolyte according to any one of claims 1 to 8, wherein the amount of iii) the at least one non-ion-conducting polymer is 1.0 to 10.0 wt %, based on the total weight of the solid composite electrolyte.

10. A method for producing the solid composite electrolyte according to any one of claims 1 to 9, comprising: - i) blending at least one solid inorganic particle with ii) at least one ionic liquid electrolyte; - iii) preparing a polymer solution of at least one non-ion-conducting polymer; - mixing said blended solid inorganic particles with said polymer solution; - casting the obtained solid composite electrolyte onto a substrate to form a wet membrane; - drying the wet film; and - calendering the membrane A method comprising:

11. A method for producing the solid composite electrolyte according to any one of claims 1 to 9, comprising: - i) blending at least one solid inorganic particle with ii) at least one ionic liquid electrolyte; - mixing the blended solid inorganic particles with iii) at least one non-ionically conductive polymer to obtain a viscous paste; and - calendering or extruding the viscous paste in successive steps to obtain a solid, uniform film; wherein iii) the at least one non-ion-conducting polymer is in a dry state.

12. A solid state battery comprising the solid composite electrolyte according to any one of claims 1 to 9.

13. Use of a solid composite electrolyte as defined in any one of claims 1 to 9 in a solid-state battery to improve ionic conductivity and mechanical properties.

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