Coated electrolyte material, process for its production and use

Description

[0001] The present invention relates to a coated electrolyte material comprising at least one sulfidic particulate lithium-ion-conductive electrolyte material, which has at least one coating, at least in some regions, that contains or consists of at least one specific inorganic-organic hybrid polymer. Furthermore, the present invention relates to a method for producing the coated electrolyte material, a solid-state electrolyte comprising the coated electrolyte material, and an energy storage device comprising the solid-state electrolyte. The present invention further relates to the use of the coated electrolyte material, the solid-state electrolyte, and the energy storage device.

[0002] To reduce greenhouse gas emissions, it is essential to introduce new, high-performance electrochemical storage devices for mobile applications. Lithium-ion conducting solid-state batteries (all-solid-state lithium batteries) are a special type of battery in which both electrodes and the electrolyte (solid-state electrolyte, optional electrolyte separator) are made of solid materials and can deliver a very high energy density. Sulfide solid-state electrolytes exhibit very high ionic conductivities of up to 10-2 S cm-1 at room temperature and, due to their mechanical properties, are easy to process. Their low chemical stability in humid air is a significant disadvantage of these sulfide electrolytes. They are hygroscopic and react with water to form H2S.All processes involving sulfide electrolytes must therefore be carried out in a dry, protective gas atmosphere. For safe battery operation, safety measures are also necessary to prevent contact of the sulfide electrolyte with water / air. At the same time, most sulfide electrolytes exhibit low stability toward lithium. This results in the formation of undesirable decomposition products that increase the interfacial resistance.

[0003] Muramatsu et al. (H. Muramatsu, A. Hayashi, T. Ohtomo, S. Hama, M. Tatsumisago, Solid State Ionics, 2011, 182, 116-119) describe a structural modification of sulfide electrolytes in which a Li 2 SP 2 S 5 glass or a Li 2 SP 2 S 5 glass-ceramic exhibits relatively high chemical stability. Raman spectroscopy showed that the 75Li 2 S 25P 2 S 5 (mol%) glass or glass-ceramic composed of Li +< and PS 4 3-< ions exhibited no obvious structural changes upon exposure to air. The composition 75Li 2 S 25P 2 S 5 generated the least amount of H 2 S in Li 2 SP 2 S 5 binary systems.

[0004] According to Hayashi et al. (A. Hayashi, H. Muramatsu, T. Ohtomo, S. Hamab, M. Tatsumisago, J. Mater. Chem. A, 2013, 1, 6320-6326), some metal oxides such as ZnO, Fe2O3, and Bi2O3 remove H2S gas and act as H2S absorbers: MxOy + H2S → MxSy + H2O. Composite electrolytes of a Li3PS4 glass and one of the metal oxides were intended to improve stability against moisture. The amounts of H2S generated decreased in proportion to the composite with Fe2O3, ZnO, and Bi2O3.

[0005] In Ohtomo et al. (T. Ohtomo, A. Hayashi, M. Tatsumisago, K. Kawamoto, Journal of Non-Crystalline Solids, 2013, 364, 57-61), H 2 S gas formation was reduced by the addition of Li 2 O during the synthesis of a sulfidic glass electrolyte (70Li 2 S·30P 2 S 5 (mol%)).

[0006] B. Zheng et al. (B. Zheng, J. Zhu, H. Wang, M. Feng, E. Umeshbabu, Y. Li, Q.-H. Wu, Y. Yang, ACS Appl. Mater. Interfaces, 2018, 10, 25473-25482) propose an approach by using a small amount of an ionic liquid to improve the stability at the Li 10 SnP 2 S 12 (LSPS) solid electrolyte / Li-metal interface.

[0007] Based on this, the object of the present invention was to provide an electrolyte material which has improved protection against moisture and increased stability against lithium.

[0008] This object is achieved with respect to a coated electrolyte material having the features of patent claim 1, with respect to a solid-state electrolyte having the features of patent claim 7, with respect to an energy storage device having the features of patent claim 8, and with respect to a method for producing the coated electrolyte material having the features of patent claim 10. Claim 9 specifies possible uses of the coated electrolyte material, the solid-state electrolyte, and the energy storage device. The respective dependent claims represent advantageous developments.

[0009] According to the invention, a coated electrolyte material is thus provided which comprises at least one sulfidic particulate lithium-ion conductive electrolyte material, which at least partially has at least one coating. The at least one coating contains or consists of at least one inorganic-organic hybrid polymer, wherein the at least one inorganic-organic hybrid polymer can be produced (or is produced) (by means of crosslinking) from at least one crosslinkable precursor comprising one or more structural units according to the following formula (I) comprises or consists of, where X is selected from the group consisting of vinyl and epoxy, R 1 is selected from the group consisting of alkyl, -O-alkyl and -O-, where -O- is a bridging group to a Si atom of the same structural unit or a further structural unit according to formula (I) of the at least one crosslinkable precursor, R 2 is selected from the group consisting of alkyl, -O-alkyl and -O-, where -O- is a bridging group to a Si atom of the same structural unit or a further structural unit according to formula (I) of the at least one crosslinkable precursor, a is a number from 1 to 20, b is a number from 1 to 20, c is a number from 1 to 30, d is a number from 0 to 20, e is 2 or 3, f is a number from 1 to 20, and g is 2 or 3.

[0010] Particularly preferably, R 1 is methyl and / or R 2 is methyl. If R 1 and / or R 2 is -O-, then this -O- represents a bridging group (ie a bridging oxygen atom) to a Si atom of the same structural unit or a further structural unit according to formula (I) of the at least one crosslinkable precursor, resulting in an Si-O-Si group in which the O atom bridges two Si atoms. For both Si atoms, the bridging group -O- then corresponds to the radical R 1 or R 2 bonded to the respective Si atom.

[0011] The sulfide particulate lithium-ion conductive electrolyte material has a coating that contains or consists of a special inorganic-organic hybrid polymer. Inorganic-organic hybrid polymers are also known under the name ORMOCER®.

[0012] The special inorganic-organic hybrid polymer contained in the coating can be produced by crosslinking a crosslinkable precursor according to the structural formula shown above. For this purpose, the crosslinkable precursor contains crosslinkable functional groups, namely vinyl groups and / or epoxy groups. Crosslinking can be achieved, for example, by polymerization, preferably using a catalyst, e.g., dibenzoyl peroxide.

[0013] Due to the coating with the special inorganic-organic hybrid polymer, the coated electrolyte material according to the invention exhibits unexpected multifunctional properties. First, the coating provides the sulfidic electrolyte material with improved protection against moisture / water or air contact, which reduces the evolution of hydrogen sulfide gas upon contact of the electrolyte material with moisture / water or air. Furthermore, the coating provides the sulfidic electrolyte material with increased stability against lithium. Furthermore, the high ionic conductivity of the sulfidic electrolyte material is essentially retained despite the presence of the coating with the inorganic-organic hybrid polymer. Therefore, the addition of lithium salts to the hybrid polymer to increase ionic conductivity is unnecessary.Furthermore, the coating of the sulfidic electrolyte material improves processability compared to the pure sulfidic electrolyte material, since the additional binding effect of the polymer reduces the occurrence of fine dust.

[0014] By coating the sulfidic electrolyte material with a coating that contains or consists of the special inorganic-organic hybrid polymer - producible from a precursor according to the structural formula shown above - an electrolyte material is obtained that has improved protection against moisture and increased stability against lithium, while at the same time maintaining the high ionic conductivity and achieving improved processability.

[0015] A preferred embodiment of the coated electrolyte material according to the invention is characterized in that the at least one sulfidic particulate lithium ion conductive electrolyte material is selected from the group consisting of Materials with the general formula Li 11-x (M 1-y M' y ) 2-x P 1+x (S 12-z M" z ), where M is selected from the group consisting of Ge, Sn and Si, where M' is selected from the group consisting of Ge, Sn and Si, where M" is selected from the group consisting of O, Se, F, Cl, Br and I, where x is a number from 0 to 2, where y is a number from 0 to 1, and where z is a number from 0 to 3, preferably Li 10 SnP 2 S 12 , Thio-LISICON materials with the general formula Li 4-x M 1-x M' x S 4 , where M is selected from the group consisting of Sn, Si, Ge and Zr, where M' is selected from the group consisting of P, Al, Zn and Ga, and where x is a number from 0 to 1, preferably Li 4 GeS 4 , Li 4 SnS 4 , the Thio-LISICON materials Li 2 GeS 3 ; Li 2 ZnGeS 4 ; Li 4-2x Zn x GeS 4 , where x is a number from 0 to 1; Li 5 GaS 4 ; Li 4+x+y (Ge 1-yx Ga x )S 4 , where x is a number from 0 to 1 and y is a number from 0 to 1;Li 2-x Sn 1-x As x S 4 , where x is a number from 0 to 1, Li-PS-based glasses and glass-ceramics with the general formula xLi 2 S·(100-x)P 2 S 5 , where x refers to mole percent and is a number from 1 to 100, and wherein the Li-PS-based glasses are optionally doped, preferably with a substance selected from the group consisting of Li 3 PO 4 , Li 4 SiO 4 , Li 4 GeO 4 , LiBO 3 , LiAlO 3 , Li 3 GaO 3 , Li 3 InO 3 , LiBH 4 , LiIl, LiCl and mixtures thereof; Li-PS-based glasses and glass-ceramics having the general formula xLi 2 S·(100-x)B 2 S 3 , where x refers to mole percent and is a number from 1 to 100, and wherein the Li-PS-based glasses are optionally doped, preferably with a substance selected from the group consisting of Li 3 PO 4 , Li 4 SiO 4 , Li 4 GeO 4 , LiBO 3 , LiAlO 3 , Li 3 GaO 3 , Li 3 InO 3 , LiBH 4 , LiIl, LiCl and mixtures thereof;Li-PS-based glasses and glass-ceramics with the general formula xLi 2 S·(100-x)SiS 2 , where x refers to mol percent and is a number from 1 to 100, and wherein the Li-PS-based glasses are optionally doped, preferably with a substance selected from the group consisting of Li 3 PO 4 , Li 4 SiO 4 , Li 4 GeO 4 , LiBO 3 , LiAlO 3 , Li 3 GaO 3 , Li 3 InO 3 , LiBH 4 , LiIl, LiCl and mixtures thereof; doped glass-ceramics selected from the group consisting of Li 7 P 2.9 S 10.85 Mo 0.01 ; Li 7 P 2.9 Mn 0.1 S 10.7 I 0.3 ; Li 7 P 2 S 8 I; Li 6 PS 5 X, where X is selected from the group consisting of Cl, Br and I, argyrodites and doped argyrodites selected from the group consisting of Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , Li 10 SiP 2 S 12 Cl 0.3 , Li 11 AlP 2 S 12 , Li 3 P 0.98 Sb 0.02 S 3.95 O 0.05 , Li 4 GeS 4 , 0.4LiI-0.24GeS 2 -0.06Ga 2 S 3 -0.3Li 2 S, 50Li 2 S-50GeS 2 , and mixtures thereof. ;

[0016] Most preferably, the at least one sulfidic particulate lithium-ion conductive electrolyte material is Li 10 SnP 2 S 12 .

[0017] According to a further preferred embodiment of the coated electrolyte material according to the invention, the at least one sulfidic particulate lithium ion-conductive electrolyte material has a primary particle size in the range of 50 nm to 10 µm, preferably in the range of 100 nm to 500 nm, particularly preferably in the range of 100 nm to 300 nm. The primary particle size can be determined, for example, using DIN ISO 22412, preferably under inert conditions.

[0018] A further preferred embodiment of the coated electrolyte material according to the invention is characterized in that the at least one crosslinkable precursor can be prepared by a hydrolysis-condensation reaction of at least one polyether-functionalized alkoxysilane, preferably of at least two polyether-functionalized alkoxysilanes, wherein the at least one polyether-functionalized alkoxysilane is preferably selected from the group consisting of triethylene glycol α-vinyl-ω-ethyl-(methyl)diethoxysilane ether, triethylene glycol α-methyl-ω-propyl-(methyl)diethoxysilane ether, and mixtures thereof. Using such a special crosslinkable precursor, a coating can be obtained which achieves particularly good protection of the sulfidic electrolyte material against moisture and particularly high stability of the sulfidic electrolyte material against lithium.

[0019] A further preferred embodiment of the coated electrolyte material according to the invention is characterized in that the at least one coating has a layer thickness in the range from 1 to 700 nm, preferably from 1 to 500 nm, particularly preferably from 1 to 300 nm, very particularly preferably from 1 to 200 nm, and / or is a nanostructured coating, and / or only decomposes thermally at temperatures above 200 °C.

[0020] A coating thickness within the specified ranges can, on the one hand, provide good protection of the sulfide electrolyte material against moisture and, on the other hand, ensure high stability of the sulfide electrolyte material against lithium. On the other hand, the coated electrolyte exhibits high ionic conductivity despite the coating at this layer thickness. The coating thickness can be determined, for example, using transmission electron microscopy, scanning electron microscopy of the particle cross-sectional area, or X-ray photon spectroscopy (depth profile).

[0021] In a further preferred embodiment of the coated electrolyte material according to the invention, the coated electrolyte material has a lithium ion conductivity at a temperature of 25 °C in the range from 1 10 -7< S / cm to 1 S / cm, preferably in the range from 1 10 -6< S / cm to 1 10 -1< S / cm, particularly preferably in the range from 1 10 -4< S / cm to 1 10 -1< S / cm.

[0022] Despite the coating, the coated electrolyte exhibits particularly high lithium-ion conductivity. The lithium-ion conductivity of the coated electrolyte can be determined, for example, using temperature-dependent impedance spectroscopy.

[0023] The present invention also relates to a solid-state electrolyte which comprises or consists of the coated electrolyte material according to the invention.

[0024] Furthermore, the present invention relates to an energy storage device comprising the solid-state electrolyte according to the invention.

[0025] The present invention also relates to the use of the coated electrolyte material according to the invention, the solid-state electrolyte according to the invention or the energy storage device according to the invention in vehicles, preferably e-cars, e-trucks, e-buses.

[0026] Furthermore, the present invention also relates to a process for producing coated electrolyte material according to the invention, in which a) at least one sulfidic particulate lithium-ion conductive electrolyte material is mixed with at least one crosslinkable precursor of at least one inorganic-organic hybrid polymer to form a mixture, and b) the at least one crosslinkable precursor of the at least one inorganic-organic hybrid polymer present in the mixture is crosslinked to form the at least one inorganic-organic hybrid polymer, thereby forming an electrolyte material coated with the at least one inorganic-organic hybrid polymer, wherein the at least one crosslinkable precursor comprises one or more structural units according to the following formula (I) comprises or consists of, where X is selected from the group consisting of vinyl and epoxy, R 1 is selected from the group consisting of alkyl, -O-alkyl and -O-, where -O- is a bridging group to a Si atom of the same structural unit or a further structural unit according to formula (I) of the at least one crosslinkable precursor, R 2 is selected from the group consisting of alkyl, -O-alkyl and -O-, where -O- is a bridging group to a Si atom of the same structural unit or a further structural unit according to formula (I) of the at least one crosslinkable precursor, a is a number from 1 to 20, b is a number from 1 to 20, c is a number from 1 to 30, d is a number from 0 to 20, e is 2 or 3, f is a number from 1 to 20, and g is 2 or 3.

[0027] Particularly preferably, R 1 is methyl and / or R 2 is methyl. If R 1 and / or R 2 is -O-, then this -O- represents a bridging group (ie a bridging oxygen atom) to a Si atom of the same structural unit or a further structural unit according to formula (I) of the at least one crosslinkable precursor, resulting in an Si-O-Si group in which the O atom bridges two Si atoms. For both Si atoms, the bridging group -O- then corresponds to the radical R 1 or R 2 bonded to the respective Si atom.

[0028] The method according to the invention produces the coated electrolyte material according to the invention in a two-stage process.

[0029] In step a), the individual components are first mixed (with or without the addition of a solvent, e.g., dichloromethane) to form a mixture. The mixing preferably results in at least one sulfidic, particulate lithium-ion-conductive electrolyte material being at least partially coated with the at least one crosslinkable precursor of the at least one inorganic-organic hybrid polymer. The components in step a) can be mixed, for example, by stirring and / or simply mixing. In addition to the sulfidic, particulate lithium-ion-conductive electrolyte material, the crosslinkable precursor of the at least one inorganic-organic hybrid polymer, and the optionally used solvent, the components to be mixed may also optionally comprise a catalyst (for subsequent crosslinking), e.g., dibenzoyl peroxide.

[0030] Finally, in step b), the crosslinkable precursor of the inorganic-organic hybrid polymer is crosslinked to form the inorganic-organic hybrid polymer, thereby obtaining the coated electrolyte material according to the invention. Crosslinking in step b) can be carried out, for example, by polymerization, preferably using a catalyst, e.g., dibenzoyl peroxide. In a solvent-based process, the solvent is removed prior to crosslinking.

[0031] A preferred variant of the process according to the invention is characterized in that the at least one crosslinkable precursor of the at least one inorganic-organic hybrid polymer is prepared by reacting at least one polyether-functionalized alkoxysilane, preferably at least two polyether-functionalized alkoxysilanes, by a hydrolysis-condensation reaction, wherein the at least one polyether-functionalized alkoxysilane is preferably selected from the group consisting of triethylene glycol α-vinyl-ω-ethyl-(methyl)diethoxysilane ether, triethylene glycol α-methyl-ω-propyl-(methyl)diethoxysilane ether, and mixtures thereof. Using such a special crosslinkable precursor, a coating can be obtained which achieves particularly good protection of the sulfidic electrolyte material against moisture and particularly high stability of the sulfidic electrolyte material against lithium.

[0032] According to a further preferred variant of the process according to the invention, a solvent, preferably dichloromethane, is additionally used in step a) and mixed with the at least one sulfidic particulate lithium-ion-conductive electrolyte material and the at least one crosslinkable precursor of the at least one inorganic-organic hybrid polymer, wherein the solvent is removed from the mixture before step b). By using a solvent, simpler and better mixing of the components can be achieved. The improved mixing leads to a more uniform coating of the sulfidic electrolyte material, thereby achieving even better protection of the sulfidic electrolyte material against moisture and even greater stability of the sulfidic electrolyte material against lithium.

[0033] A further preferred variant of the process according to the invention is characterized in that, in step a), at least one catalyst, preferably dibenzoyl peroxide, is additionally mixed with the at least one sulfidic particulate lithium-ion-conductive electrolyte material and the at least one crosslinkable precursor of the at least one inorganic-organic hybrid polymer, wherein the crosslinking in step b) occurs by polymerization. By using a catalyst, faster and simpler crosslinking by polymerization can be achieved. In particular, crosslinking can be carried out at lower temperatures by using a catalyst.

[0034] A further preferred variant of the process according to the invention is characterized in that the mixture in step b) is subjected to a heat treatment at a temperature in the range from 20°C to 140°C, preferably in the range from 60°C to 100°C, particularly preferably in the range from 70°C to 90°C, for a period of 10 minutes to 72 hours, preferably from 30 minutes to 36 hours, particularly preferably from 60 minutes to 24 hours. Such a heat treatment can achieve particularly good crosslinking and thus a very uniform coating, thereby achieving even better protection of the sulfidic electrolyte material against moisture and even greater stability of the sulfidic electrolyte material against lithium.

[0035] According to a further preferred variant of the process according to the invention, the mixing in step a) is carried out by stirring and / or mixing, wherein the stirring preferably results in a homogeneous mixture. By producing a homogeneous mixture, a particularly uniform coating can subsequently be achieved, thereby achieving even better protection of the sulfidic electrolyte material against moisture and even greater stability of the sulfidic electrolyte material against lithium.

[0036] The present invention will be explained in more detail with reference to the following figures and examples, without limiting it to the specific embodiments and parameters shown here.

[0037] Fig. 1shows a schematic representation of an exemplary two-stage production of the coated electrolyte material according to the invention. On the left, a particle of a sulfidic particulate lithium-ion conductive electrolyte material ("S-electrolyte") used as starting material is shown. In the first process step, the sulfidic particulate lithium-ion conductive electrolyte material is mixed with a crosslinkable precursor of an inorganic-organic hybrid polymer ("hybrid polymer precursor"). As a result, the sulfidic particulate lithium-ion conductive electrolyte material is at least partially coated with the crosslinkable precursor of the inorganic-organic hybrid polymer. An example is shown in the middle of the diagram in Fig. 1such a coated particle of the particulate electrolyte material is shown. In the second process step, the crosslinkable precursor of the inorganic-organic hybrid polymer is crosslinked to form the at least one inorganic-organic hybrid polymer. This results in an electrolyte material according to the invention coated with the inorganic-organic hybrid polymer, of which Fig. 1 a particle is shown as an example.

[0038] Fig. 2 shows two SEM images, wherein figure a) shows the image of a pure (i.e. uncoated) sulphidic electrolyte material and figure b) shows the image of a coated sulphidic electrolyte material according to the invention.

[0039] Fig. 3shows the H 2 S gas evolution of a pure (i.e., uncoated or untreated) sulfidic electrolyte material and of a coated sulfidic electrolyte material according to the invention upon contact with air (humidity 47-49%) as a function of time. It can be seen that by coating the sulfidic electrolyte material with the special inorganic-organic hybrid polymer, the hydrogen sulfide evolution is reduced by a factor of > 4 compared to the pure (i.e., uncoated or untreated) sulfidic electrolyte upon contact with air (1 hour, humidity 47-49%). The coated electrolyte material according to the invention thus exhibits improved protection against moisture / water or air contact due to the coating with the special inorganic-organic hybrid polymer.

[0040] Fig. 4shows the ionic conductivity of a pure (i.e. uncoated or untreated) sulfidic electrolyte material and of a coated sulfidic electrolyte material according to the invention as a function of pressure. Fig. 5shows the ionic conductivity of a pure (i.e., uncoated or untreated) sulfidic electrolyte material and a coated sulfidic electrolyte material according to the invention as a function of temperature. It can be seen that—despite the lower ionic conductivity of the special inorganic-organic hybrid polymer compared to the pure (i.e., uncoated or untreated) sulfidic electrolyte material—the conductivities of the coated sulfidic electrolyte material according to the invention and the pure (i.e., uncoated) sulfidic electrolyte material are virtually identical over a wide pressure and temperature range. The addition of lithium salts to the inorganic-organic hybrid polymer to increase the ionic conductivity is therefore unnecessary.

[0041] Fig. 6shows the diagram of a "lithium stripping / plating" test with varying current densities using a symmetrical cell (Cu-mesh / Li / coated sulfidic electrolyte / Li / Cu-mesh). The coated sulfidic electrolyte consists of a coated electrolyte material according to the invention. It can be seen that coating the sulfidic electrolyte with the special inorganic-organic hybrid polymer leads to increased stability against lithium (cf. B. Zheng et al., ACS Appl. Mater. Interfaces, 2018, 10, 25473-25482; Figure 3 ). Example:

[0042] 3.0 g of Li 10 SnP 2 S 12 , 0.6 g of a precursor of an inorganic-organic hybrid polymer, 0.024 g of dibenzoyl peroxide, and 15.0 g of dichloromethane are weighed into a 50 mL flask. The suspension is then homogenized for 20 minutes with stirring at room temperature. The mixture is then heated to 50 °C, and dichloromethane is removed. After the dichloromethane has been completely removed, the temperature is increased to 80 °C, and the polymerization of the precursor of the inorganic-organic hybrid polymer is carried out within 16 hours. An electrolyte material according to the invention coated with an inorganic-organic hybrid polymer is obtained.

[0043] The precursor of the inorganic-organic hybrid polymer used is a precursor that comprises or consists of one or more structural units according to formula (I). The precursor of the inorganic-organic hybrid polymer used can be prepared, for example, according to the following two variants (cf. N. Boaretto et al., Journal of Power Sources, 2016, 325, 427-437): Variant 1:

[0044] Me-TEG-PMDES (5 g, 0.015 mol), Vi-TEG-EMDES (1.69 g, 0.005 mol), H 2 O (1.44 g, 0.08 mol), and tetrabutylammonium fluoride trihydrate (TBAF, 0.095 g, 3 10 -4 mol) were mixed in 20 mL of diethyl carbonate. The solution was stirred at 50 °C for 3 days. The volatiles were removed under reduced pressure, and the residue was dissolved in dry diethyl ether and filtered over Al 2 O 3 . The diethyl ether was then removed, and the product was dried at 50 °C and 0.02 mbar for 24 h. A precursor of an inorganic-organic hybrid polymer was obtained. Vi-TEG-EMDES: Triethylene glycol-α-vinyl-ω-ethyl-(methyl)diethoxysilane ether Me-TEG-PMDES: Triethylene glycol α-methyl-ω-propyl-(methyl)diethoxysilane ether Variant 2:

[0045] Me-TEG-PMDES (5 g, 0.015 mol), Vi-TEG-EMDES (5 g, 0.015 mol), H 2 O (2.16 g, 0.12 mol), and tetrabutylammonium fluoride trihydrate (TBAF, 0.095 g, 3 10 -4 < mol) were mixed in 20 mL of diethyl carbonate. The solution was stirred at 50 °C for 3 days. The volatiles were removed under reduced pressure, and the residue was dissolved in dry diethyl ether and filtered over Al 2 O 3 . The diethyl ether was then removed, and the product was dried at 50 °C and 0.02 mbar for 24 h. A precursor of an inorganic-organic hybrid polymer was obtained. Vi-TEG-EMDES: Triethylene glycol-α-vinyl-ω-ethyl-(methyl)diethoxysilane ether Me-TEG-PMDES: Triethylene glycol α-methyl-ω-propyl-(methyl)diethoxysilane ether

Claims

1. Coated electrolyte material, comprising at least one sulfidic particulate lithium-ion-conductive electrolyte material, which has, at least in regions, at least one coating which contains or consists of at least one inorganic-organic hybrid polymer, wherein the at least one inorganic-organic hybrid polymer is preparable from at least one cross-linkable precursor which contains or consists of one or more structural units according to the following formula (I) wherein X is selected from the group consisting of vinyl and epoxy, R1 is selected from the group consisting of alkyl, -O-alkyl, and -O-, wherein -O- is a bridging group to an Si atom of the same structural unit or a further structural unit according to the formula (I) of the at least one cross-linkable precursor, R2 is selected from the group consisting of alkyl, -O-alkyl, and -O-, wherein -O- is a bridging group to an Si atom of the same structural unit or a further structural unit according to the formula (I) of the at least one cross-linkable precursor, a is a number from 1 to 20, b is a number from 1 to 20, c is a number from 1 to 30, d is a number from 0 to 20, e is 2 or 3, f is a number from 1 to 20, and g is 2 or 3.

2. Coated electrolyte material according to claim 1, characterized in that the at least one sulfidic particulate lithium-ion-conductive electrolyte material is selected from the group consisting of - materials having the general formula Li11-x(M1-yM'y)2-xP1+x(S12-zM"z), wherein M is selected from the group consisting of Ge, Sn, and Si, wherein M' is selected from the group consisting of Ge, Sn, and Si, wherein M" is selected from the group consisting of O, Se, F, Cl, Br, and I, wherein x is a number from 0 to 2, wherein y is a number from 0 to 1, and wherein z is a number from 0 to 3, preferably Li10SnP2S12, - thio-LISICON materials having the general formula Li4-xM1-xM'xS4, wherein M is selected from the group consisting of Sn, Si, Ge, and Zr, wherein M' is selected from the group consisting of P, Al, Zn, and Ga, and wherein x is a number from 0 to 1, preferably Li4GeS4, Li4SnS4, - the thio-LISICON materials Li2GeS3; Li2ZnGeS4; Li4-2xZnxGeS4, wherein x is a number from 0 to 1; Li3GaS4; Li4+x+y(Ge1-y-xGax)S4, wherein x is a number from 0 to 1 and y is a number from 0 to 1; Li2-xSn1-xAsxS4, wherein x is a number from 0 to 1, - Li-P-S-based glasses and glass ceramics having the general formula xLi2S·(100-x)P2S5, wherein x relates to mole percentage and is a number from 1 to 100, and wherein the Li-P-S-based glasses are optionally doped, preferably with a substance selected from the group consisting of Li3PO4, Li4SiO4, Li4GeO4, LiBO3, LiAlO3, Li3GaO3, Li3InO3, LiBH4, Lil, LiCl, and mixtures thereof; - Li-P-S-based glasses and glass ceramics having the general formula xLi2S·(100-x)B2S3, wherein x relates to mole percentage and is a number from 1 to 100, and wherein the Li-P-S-based glasses are optionally doped, preferably with a substance selected from the group consisting of Li3PO4, Li4SiO4, Li4GeO4, LiBO3, LiAlO3, Li3GaO3, Li3InO3, LiBH4, Lil, LiCl, and mixtures thereof; - Li-P-S-based glasses and glass ceramics having the general formula xLi2S·(100-x)SiS2, wherein x relates to mole percentage and is a number from 1 to 100, and wherein the Li-P-S-based glasses are optionally doped, preferably with a substance selected from the group consisting of Li3PO4, Li4SiO4, Li4GeO4, LiBO3, LiAlO3, Li3GaO3, Li3InO3, LiBH4, Lil, LiCl, and mixtures thereof; - doped glass ceramics selected from the group consisting of Li7P2.9510.85Mo0.01; Li7P2.9Mn0.1S10.7I0.3; Li7P2S8I; Li6PS5X, wherein X is selected from the group consisting of Cl, Br, and I, - argyrodites and doped argyrodites selected from the group consisting of Li9.54Si1.74P1.44511.7Cl0.3, Li10SiP2S12Cl0.3, Li11AlP2S12, Li3P0.98Sb0.02S3.95O0.05, Li4GeS4, 0.4LiI-0.24GeS2-0.06Ga2S3-0.3Li2S, 50Li25-50GeS2, and - mixtures thereof.

3. Coated electrolyte material according to any one of the preceding claims, characterized in that the at least one sulfidic particulate lithium-ion-conductive electrolyte material has a primary particle size, determined by means of DIN ISO 22412, in the range of 50 nm to 10 µm, preferably in the range of 100 nm to 500 nm, particularly preferably in the range of 100 nm to 300 nm.

4. Coated electrolyte material according to any one of the preceding claims, characterized in that the at least one cross-linkable precursor is preparable by means of a hydrolysis-condensation reaction of at least one polyether-functionalized alkoxysilane, preferably of at least two polyether-functionalized alkoxysilanes, wherein the at least one polyether-functionalized alkoxysilane is preferably selected from the group consisting of triethylene glycol α-vinyl ω-ethyl(methyl)diethoxysilane ether, triethylene glycol α-methyl ω-propyl (methyl)diethoxysilane ether, and mixtures thereof.

5. Coated electrolyte material according to any one of the preceding claims, characterized in that the at least one coating - has a layer thickness in the range of 1 to 700 nm, preferably of 1 to 500 nm, particularly preferably of 1 to 300 nm, most particularly preferably of 1 to 200 nm, and / or - is a nanostructured coating.

6. Coated electrolyte material according to any one of the preceding claims, characterized in that the coated electrolyte material has a lithium-ion conductivity, determined by means of temperature-dependent impedance spectroscopy, at a temperature of 25°C in the range of 1·10-7 S / cm to 1 S / cm, preferably in the range of 1·10-6 S / cm to 1 · 10-1 S / cm, particularly preferably in the range of 1 · 10-4 S / cm to 1 · 10-1 S / cm.

7. Solid-state electrolyte comprising or consisting of a coated electrolyte material according to any one of the preceding claims.

8. Energy storage comprising a solid-state electrolyte according to claim 7.

9. Use of a coated electrolyte material according to any one of claims 1 to 6, of a solid-state electrolyte according to claim 7, or of an energy storage according to claim 8, in vehicles, preferably electric cars, electric trucks, electric buses.

10. Method for preparing coated electrolyte material according to any one of claims 1 to 6, in which a) at least one sulfidic particulate lithium-ion-conductive electrolyte material is mixed with at least one cross-linkable precursor of at least one inorganic-organic hybrid polymer to form a mixture, and b) the at least one cross-linkable precursor of the at least one inorganic-organic hybrid polymer which is present in the mixture is cross-linked to form the at least one inorganic-organic hybrid polymer, wherein electrolyte material coated with the at least one inorganic-organic hybrid polymer results, wherein the at least one cross-linkable precursor contains or consists of one or more structural units according to the following formula (I) wherein X is selected from the group consisting of vinyl and epoxy, R1 is selected from the group consisting of alkyl, -O-alkyl, and -O-, wherein -O- is a bridging group to an Si atom of the same structural unit or a further structural unit according to the formula (I) of the at least one cross-linkable precursor, R2 is selected from the group consisting of alkyl, -O-alkyl, and -O-, wherein -O- is a bridging group to an Si atom of the same structural unit or a further structural unit according to the formula (I) of the at least one cross-linkable precursor, a is a number from 1 to 20, b is a number from 1 to 20, c is a number from 1 to 30, d is a number from 0 to 20, e is 2 or 3, f is a number from 1 to 20, and g is 2 or 3.

11. Method according to claim 10, characterized in that the at least one cross-linkable precursor of the at least one inorganic-organic hybrid polymer is prepared by means of a reaction of at least one poly-etherfunctionalized alkoxysilane, preferably at least two polyether-functionalized alkoxysilanes, by means of a hydrolysis-condensation reaction, wherein the at least one polyether-functionalized alkoxysilane is preferably selected from the group consisting of triethylene glycol α-vinyl ω-ethyl(methyl)diethoxysilane ether, triethylene glycol α-methyl ω-propyl (methyl)diethoxysilane ether, and mixtures thereof.

12. Method according to claim 10 or 11, characterized in that a solvent, preferably dichloromethane, is additionally used in step a) and is mixed with the at least one sulfidic particulate lithium-ion-conductive electrolyte material and the at least one cross-linkable precursor of the at least one inorganic-organic hybrid polymer, wherein the solvent is removed from the mixture before step b).

13. Method according to any one of claims 10 to 12, characterized in that at least one catalyst, preferably dibenzoyl peroxide, is additionally mixed, in step a), with the at least one sulfidic particulate lithium-ion-conductive electrolyte material and the at least one cross-linkable precursor of the at least one inorganic-organic hybrid polymer, wherein the cross-linking takes place in step b) by polymerization.

14. Method according to any one of claims 10 to 13, characterized in that the mixture is subjected to a heat treatment at a temperature in the range of 20°C to 140°C, preferably in the range of 60°C to 100°C, particularly preferably in the range of 70°C to 90°C, in step b) for a time period of 10 minutes to 72 hours, preferably of 30 minutes to 36 hours, particularly preferably of 60 minutes to 24 hours.

15. Method according to any one of claims 10 to 14, characterized in that the mixing in step a) takes place by stirring and / or mixing, wherein a homogeneous mixture is preferably obtained by stirring.