Organic coating for sulfide-containing solid electrolyte material, solid electrolyte, and solid battery containing the same

Abstract

A coated sulfide-containing solid electrolyte material, the solid electrolyte, and a solid-state battery comprising the solid electrolyte are disclosed. According to aspects of this disclosure, the coating is formed on the surface of the sulfide-containing solid electrolyte material and comprises a compound having a thiol with a long hydrophobic tail, such as 1-undecanethiol. The coating can provide, for example, protection from air and moisture under ambient conditions.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to U.S. Provisional Application No. 63 / 505,240 filed on 31 May 2023, U.S. Regular Application No. 18 / 661,381 filed on 10 May 2024, and Korean Patent Application No. 10-2024-0070959 filed on 30 May 2024, the entire contents of which are expressly incorporated herein by reference.

[0002] Technical field This disclosure relates to an organic coating for a sulfide-containing solid electrolyte material, the solid electrolyte, and the solid battery thereof. According to an aspect of this disclosure, the organic coating is manufactured from a thiol having a hydrophobic chain, which protects the sulfide-containing solid electrolyte material from air and moisture under ambient conditions. [Background technology]

[0003] Electric transportation systems and fixed-station energy storage systems continue to increase. Therefore, the importance of high-energy-density battery technology with improved safety features is growing.

[0004] Much effort has been put into using lithium metal as the negative electrode. Lithium (Li) metal has a capacity of 3860 mAh g compared to standard hydrogen electrodes. -1 Due to its high specific capacity and low electrochemical potential of -3.040V, it is believed that it can meet high energy density requirements. However, commercialization using lithium metal anodes together with conventional flammable organic liquid electrolytes (OLEs) has faced many obstacles, including undesirable reactions between lithium metal and OLE. Furthermore, flammable OLEs also present safety concerns.

[0005] To avoid the safety problems of conventional lithium-ion batteries that use flammable organic electrolytes, all-solid-state batteries (ASSBs) that use non-flammable solid electrolytes are being widely promoted. Solid electrolytes also ensure better interfacial stability and pave the way for the use of lithium metal as the negative electrode, resulting in batteries with higher energy density. Solid electrolytes (SEs) are stable at high temperatures, have improved safety (e.g., can reduce the risk of fire and explosion), and possess good ionic conductivity and excellent ductility. In particular, sulfide-containing SEs have high ionic conductivity at room temperature (e.g., Li 10 GeP2S 12 12 mS cm -1 and Li 5.5 PS 4.5 Cl 1.5 9.4 mS cm -1 This has been studied using OLE, and it surpasses it. Furthermore, the flexible properties of sulfide-containing SE can enable high ductility, which can be useful at solid-solid interfaces. Therefore, it is expected that SE can be used to provide longer battery life.

[0006] However, despite various studies, certain limitations still need to be overcome. For example, sulfide-containing solid electrolytes are hypersensitive to moisture, which hinders their practical manufacture. Another major limitation is their extremely low air stability. Hydrolysis produces toxic H2S gas, along with a fatal loss of ionic conductivity.

[0007] Sulfide-containing solid electrolytes have low chemical stability and are therefore generally handled in inert glove boxes with very low moisture levels (dew point -80°C). However, maintaining such moisture levels in practical applications and commercialization is too costly.

[0008] The reason for the low chemical stability is due to the structure, chemical bonds, and non-bridging sulfur units in the glass network of most sulfide electrolyte materials. Glasses with a low concentration of Li modifier units are more chemically stable because they have fewer non-bridging sulfur bonds that are vulnerable to chemical degradation. Lithium ions form ionic bonds with sulfur, which are generally weaker than other covalent bonds in the glass network, making lithium ions more likely to leach out through reaction with water. To realize sulfide solid electrolytes for all-solid-state batteries, it is necessary to solve the problem of chemical stability.

[0009] Researchers have examined this problem through various approaches, such as (1) suppressing the generation of H2S by adding metal oxides (ZnO, Fe2O3, Bi2O3, etc.) to sulfide SE to absorb H2S, (2) partially substituting S with O to form oxysulfides with improved air stability and a wide electrochemical window, (3) chemical doping or substitution based on the hard / soft acid-base theory, or (4) designing and adjusting the nanostructure of the material, for example, by core-shell coating, to protect it from moisture and air.

[0010] The aforementioned approaches have improved the chemical stability of sulfide solid electrolytes. However, problems still remain. For example, metals have a large negative Gibbs free energy change (ΔG) for the reaction M x O y + H2S → M x S y + H2O, so they absorb H2S by undergoing an acid-base reaction with H2S. Although effective for moisture protection, the introduction of non-ion-conductive substances, which are "foreign substances," reduces the ionic conductivity. For example, ZnO can effectively absorb H2S but may also reduce the conductivity.

[0011] The hard acid (small, non-polar) P 5+ is replaced with the soft acid (large, polar) Cu +15 , As 5+16 , Sn 4+17 and Sb 5+18If substituted, the ion becomes a soft base S 2- It binds firmly to the hard base O 2- To resist the attack, rapid hydrolysis can be mitigated. While the chemical stability of the electrolyte itself can be improved, interfacial stability with lithium metal is often sacrificed, impairing the overall efficiency of the all-solid-state battery.

[0012] Constructing new nanostructures and fine-tuning the morphology of sulfide electrolytes can be effectively done on a laboratory scale. However, scaling this up to a manufacturing level is not only impractical but can also lead to a decrease in conductivity.

[0013] Therefore, despite efforts to improve the chemical stability of sulfide-containing electrolytes, many drawbacks remain, such as in conductivity or interfacial stability. Consequently, the need for improved all-solid-state batteries still persists. [Overview of the Initiative] [Problems that the invention aims to solve]

[0014] This disclosure relates to sulfide-containing solid electrolyte materials, the solid electrolyte, and the provision of improved stability for solid-state batteries. The solid electrolyte (SSE) can also pave the way for the realization of lithium metal anodes that enable high cell energy density by ensuring higher interfacial stability and better mechanical properties and suppressing Li dendrite penetration. [Means for solving the problem]

[0015] This disclosure relates to organic coatings for sulfide-containing solid electrolytes suitable for use in solid-state batteries, and to the use of coated sulfide-containing solid electrolytes and sulfide-containing solid electrolyte compositions. According to this disclosure, the stability of sulfide-containing solid electrolyte compositions is improved, for example, to moisture and / or air, and processing under ambient conditions becomes easier. Furthermore, this disclosure relates to providing solid-state batteries with good electrical and chemical properties, including safety, thermal stability, energy density, lifetime characteristics, and Coulomb efficiency. It will be readily apparent that these and other objectives and advantages of this disclosure can be achieved by the means or methods described in the appended claims, and in combination thereof.

[0016] Sulfide solid electrolytes are promising candidates for realizing all-solid-state batteries (ASSBs) due to their excellent ionic conductivity and ductility. However, they are highly sensitive to moisture, requiring processing environments incompatible with today's lithium-ion battery manufacturing infrastructure. For example, in the case of lithium argyrodite, cross-linked sulfur units (PSPs) in the reticular structure can react with water to produce OH and SH species, which further react to produce both OH and toxic H2S gas. During the hydrolysis process, these species can attach PS bonds, thereby forming PO bonds, which are crucial for high Li ionic conductivity. 3- By causing the units to disintegrate, H2S is released.

[0017] Because moisture sensitivity can lead to a fatal loss of ionic conductivity, scientific research requires handling sulfide SSEs in an inert glovebox atmosphere with exceptionally low moisture levels (dew point -80°C). In industrial environments, a dry room with a dew point below -60°C is required, which is far more cumbersome and costly than the current lithium-ion battery manufacturing infrastructure with a dew point of ~-40°C.

[0018] One aspect described herein relates to a reversible surface modification strategy that enables processing of sulfide SSEs (e.g., Li6PS5Cl) under humid ambient air. This protective mechanism does not significantly alter the ionic conductivity and redox stability of the material and can be effective for extended periods (e.g., several hours to several days or more). Long-chain alkylthiols, such as 1-undecanethiol, have been shown to be chemically compatible with electrolytes and have minimal effect on their ionic conductivity. Importantly, thiol modification limits the structural degradation of sulfide SSEs and extends the amount of time they can be exposed to air at 33% relative humidity (33%RH), up to a maximum of 2 days (1 mS cm). -1 This maintains the aforementioned conductivity while improving protection time by more than 100 times compared to competing approaches. Experimental and computational results indicate that the thiol group is fixed to the SSE surface, while the hydrophobic hydrocarbon tail repels water, thus providing protection. The modified Li6PS5Cl SSE is Li 0.5 In / Li Mon 0.8 Co 0.1 Mn 0.1 When embodied in O2ASSB, it maintains its function even after exposure to ambient humidity. This protection strategy, proposed based on surface molecular interactions, represents a significant step towards the production of cost-competitive and energy-efficient sulfide SSEs for ASSB applications.

[0019] One aspect of the present disclosure relates to a sulfide-containing solid electrolyte having an organic coating, and a solid-state battery comprising the electrolyte. In a particular embodiment, the organic coating is a protective agent for the sulfide-containing solid electrolyte under ambient conditions. For example, the organic coating can provide protection from moisture and / or air.

[0020] In one aspect of this disclosure, an organic coating is formed of long-chain thiols and applied to a sulfide-containing solid electrolyte material such as Li6PS5Cl(LPSCl). The effect of the coating on the ionic conductivity of the electrolyte is negligible. Some mechanistic studies have shown that the thiol groups interact with surface sulfur (sulfur in the sulfide-containing solid electrolyte), while the hydrocarbon tails provide a protective function. For example, the hydrocarbon tails can be oriented outward and form a "lipid barrier" that repels water and other polar substances. As shown in Figure 1, the thiol-coated electrolyte (e.g., where the thiol groups interact with the LPSCl surface) provides hydrophobic tail ends, which block water and protect the electrolyte.

[0021] In one embodiment, the coating extends the time that the material can be exposed to ambient air with a maximum humidity of 20% for up to three days without significant degradation of structure and conductivity. This durability represents an improvement of more than two orders of magnitude compared to competing approaches. The coated LPSCl was also shown to maintain its functionality when embodied in a solid-state battery with an oxide cathode. Therefore, this protective mechanism based on surface molecular interactions represents an important step in applying sulfide electrolytes to all-solid-state batteries for practical application and commercialization.

[0022] One embodiment relates to a solid electrolyte composition comprising a sulfide-containing solid electrolyte material having a surface, wherein an organic coating is formed on the surface of the sulfide-containing solid electrolyte material. The organic coating is formed on the surface of the sulfide-containing solid electrolyte material. In some embodiments, the organic coating is formed of at least one of the compounds of the following chemical formulas 1 and 2: [Chemical formula 1] RA [Chemical formula 2] R-A'-R In the above formula, A is an SH group, an isocyanate, an amine, or a leaving group (including, but not limited to, organosilicon compounds such as triethoxysilyl or trimethoxysilyl); A' is an -S- or -SS- moiety; and each R is independently a substituted or unsubstituted C3-C20 alkyl group. A solid electrolyte for a solid battery can then be prepared using the above solid electrolyte composition.

[0023] In one embodiment, the organic coating is formed by adsorption onto the surface of the sulfide-containing solid electrolyte material. Thus, in some embodiments, the compound of chemical formula 1 or chemical formula 2 is attached to the surface of the sulfide-containing solid electrolyte material by non-covalent adhesion (including, but not limited to, chemiadsorption, van der Waals interactions, or ionic interactions).

[0024] Alternatively, the coating may be formed by the reaction of a compound of chemical formula 1 and / or chemical formula 2 with a sulfide-containing solid electrolyte material, for example, the reaction product or residue of the compound of chemical formula 1 and / or chemical formula 2 forms the coating. Thus, in some embodiments of this disclosure, the compound of chemical formula 1 or chemical formula 2 reacts with the sulfide-containing solid electrolyte material to form a covalent bond. In some embodiments, the resulting covalent bond is a sulfide bond or a disulfide bond.

[0025] In some embodiments, A in the compound of chemical formula 1 is a thiol (-SH group), an isocyanate, an amine, or a suitable leaving group. In some embodiments of this disclosure, the leaving group may be a triethoxysilyl or a trimethoxysilyl.

[0026] In one embodiment, at least one of the R atoms in the compound of chemical formula 1 or chemical formula 2 is a C6-C16 alkyl group. In another embodiment, at least one of the R atoms in the compound of chemical formula 1 or chemical formula 2 is a C8-C12 alkyl group.

[0027] In one embodiment, the total number of carbon atoms in the compound of chemical formula 1 or chemical formula 2 is 6 to 16. In another embodiment, the total number of carbon atoms in the compound of chemical formula 1 or chemical formula 2 is 8 to 12.

[0028] In one embodiment, at least one of the R in the compound of chemical formula 1 or chemical formula 2 is a substituted C3-C20 alkyl group, and the substituted C3-C20 alkyl group has one or more substituents selected from fluorine, chlorine, bromine, ester, and ketone moieties.

[0029] In one embodiment, each R group provides a compound of chemical formula 1 or 2 that is an amphiphilic molecule (for example, the R group can repel water and polar organic solvents) and is selected to chemically adsorb to the surface of a sulfide solid electrolyte. See, for example, Figures 1a and 1b. The head group can enable both stabilization of the sulfide SSE surface and adhesion to the sulfide SSE surface. For example, in the case of an A-thiol head group, it is not expected to replace the S atom of the conventional PS bond in the SSE, but rather to adhere to the S atom on the surface through the formation of an SS bond. A sufficiently long alkyl tail (e.g., C) 11 H 23 High hydrophobicity can be ensured by (-).

[0030] In one embodiment, the compound of chemical formula 1 is 1-undecanethiol. As will be explained below, 1-undecanethiol is chemically compatible with electrolytes and has only a minimal effect on ionic conductivity. For example, thiol modification limits the structural degradation of sulfide SSE and extends the amount of time it can be exposed to air at a relative humidity of 33% (33%RH), up to a maximum of 2 days at 1 mS cm. -1 The above conductivity was maintained, and the protection time was improved by more than 100 times compared to competing approaches. Experimental and computational results showed that the thiol groups were fixed to the SSE surface, while the hydrophobic hydrocarbon tails repelled water, thus providing protection. The modified Li6PS5Cl SSE is Li 0.5 In / Li Mon 0.8 Co 0.1Mn 0.1 When embodied in O2ASSB, it maintains its function even after exposure to ambient humidity. This protection strategy, proposed based on surface molecular interactions, represents a significant step towards the production of cost-competitive and energy-efficient sulfide SSEs for ASSB applications.

[0031] In one embodiment, the sulfide-containing solid electrolyte material is selected from the group consisting of inorganic electrolyte materials and organic electrolyte materials. According to an embodiment of this disclosure, the sulfide-containing solid electrolyte material is an inorganic electrolyte.

[0032] In some aspects of the present invention, the sulfide-containing solid electrolyte material is Li3P7S 11 Li3P7S 11 Li 10 GeP2S 12 It contains at least one selected from the group consisting of Na3PS4 and Li6PS5Cl. Among SSE materials, Li 9.6 P3S 12 Li 10 GeP2S 12 , and Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Sulfides like these have superionic conductivity (~10 -2 S cm -1 They are particularly attractive due to their high degree of Young's modulus and deformability. Furthermore, sulfide SSEs exhibit lower Young's modulus values ​​than oxide glasses and ceramics, which is beneficial for creating favorable interfacial contact with electrode materials through mechanical compression.

[0033] In some aspects of this disclosure, the sulfide-containing solid electrolyte material includes at least one selected from the group consisting of LPS-based glass and glass ceramics of the formula xLi2S-yP2S5 (where x+y=1).

[0034] In some embodiments of the present invention, the sulfide-containing solid electrolyte material comprises an argyrodite-based solid electrolyte of the formula Li6PS5X (where X is Cl, Br, or I).

[0035] In some embodiments of the present invention, the sulfide-containing solid electrolyte material is of formula Li 6-y PS 5-y Cl 1+y It contains an argyrodite-based solid electrolyte (where y < 1).

[0036] In another aspect, the disclosure relates to a method for producing a solid electrolyte composition, the method for producing the solid electrolyte composition comprising providing a sulfide-containing solid electrolyte material and combining at least one of the compounds of chemical formula 1 or chemical formula 2 described herein to form a coated sulfide-containing solid electrolyte material.

[0037] In another aspect, the disclosure relates to a method for producing a solid electrolyte, the method for producing the solid electrolyte comprising providing a sulfide-containing solid electrolyte and combining the solid electrolyte with at least one of the compounds of one chemical formula 1 and one chemical formula 2 described herein to form a coated sulfide-containing solid electrolyte material.

[0038] Another embodiment relates to a solid electrolyte comprising the solid electrolyte composition.

[0039] Other embodiments relate to an all-solid-state battery comprising a negative electrode; a positive electrode; and a solid electrolyte interposed between the negative electrode and the positive electrode, as described herein. [Effects of the Invention]

[0040] This specification describes sulfide-containing solid electrolyte compositions, and solid electrolytes and solid batteries, which use an organic coating to protect the sulfide-containing electrolyte from air and / or moisture.

[0041] For example, an organic coating of long-chain alkylthiols (e.g., 1-undecanethiol) chemically adsorbed onto the surface of a sulfide electrolyte protects the material from moisture and air. In Figure 1, 1-undecanethiol is adsorbed onto the surface of Li6PS5Cl and can adhere, for example, via weak van der Waals forces. The hydrophilic functional thiol group interacts with Li6PS5Cl to form a weak bond, while the hydrophobic carbon tail acts as a water-repellent shield. The non-invasive 1-undecanethiol coating has been demonstrated to protect Li6PS5Cl from moisture and air without damaging its conductivity. The integrity of the crystal and bonding structure was confirmed by X-ray powder diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), as described in detail herein.

[0042] Coated solid electrolyte materials have been shown to maintain their performance in both lithium symmetric cells and full cells after exposure to air or moisture. The inventors have discovered, for example, that coatings formed with long-chain alkylthiols protect sulfide solid electrolytes from air or moisture, opening the way for large-scale production even under ambient conditions.

[0043] According to this disclosure, sulfide-containing solid electrolyte materials (e.g., LPSCs) can be used openly for extended periods under ambient conditions, significantly simplifying the manufacturing process and facilitating commercialization.

[0044] For example, in one embodiment, LPSCs coated with 1-undecanethiol were evaluated after being exposed to ambient air for up to 7 days. The material's changes after air exposure were observed via XRD, Raman spectroscopy, and XPS. It was found that 1-undecanethiol was able to protect the LPSCs from ambient air for up to 3 days while minimizing conductivity loss. XRD results (Figures 2a and 3a) showed no signs of new phase formation during the up to 3 days of air exposure, indicating that the integrity of the LPSC's original structure remained unchanged, thus demonstrating that 1-undecanethiol functioned properly as a protective agent. A small second phase peak was observed on the 5th day of air exposure. The main LPSC peak remained until the 7th day, but the impurity peak was more pronounced.

[0045] The accompanying drawings illustrate aspects of the disclosure and, together with the detailed disclosure, serve to further illustrate the technical ideas of the disclosure; the disclosure should not be construed as being limited to the drawings. In the drawings, the shape, size, volume or proportion of elements may be exaggerated or emphasized for clarity of explanation. [Brief explanation of the drawing]

[0046] [Figure 1a] This is a schematic diagram of an organic compound (1-undecanethiol) coated onto an LPSC to form a thiol-coated LPSC for moisture protection. [Figure 1b] This is a schematic diagram illustrating a LPSC protection strategy in humid ambient air. LPSCs undergo hydrolysis, resulting in a 104-fold decrease in ionic conductivity, while 1-undecanethiol (SH) adsorbed on the LPSC surface protects the material, with a conductivity loss of less than 10 times at 33% relative humidity (RH). SH forms a hydrophobic shield around the LPSC particles. [Figure 2a] This shows PXRD refining after vacuum drying of 1-undecanethiol (or "11Thiol") mixed with LPSC. [Figure 2b] The electrochemical impedance spectroscopy results for LPSC and LPSC / 11Thiol mixtures are shown. [Figure 3a] This shows the PXRD results of 1-undecanethiol coated LPSCs based on the air exposure time mentioned, and studies the structural changes of 1-undecanethiol mixed with LPSCs from day 1 to day 7. [Figure 3b] The Raman spectroscopy of untreated (pristine) LPSC and LPSC / 1-undecanethiol mixture after exposure to air for 1 to 7 days is shown. [Figure 3c] The electrochemical impedance spectroscopy results for LPSC and LPSC / 1-undecanethiol mixtures from day 1 to day 7 of exposure to air are shown. [Figure 3d] The XPS results for LPSC and LPSC / 1-undecanethiol mixtures after exposure to air from day 1 to day 7 are shown. [Figure 3e] The XPS results for LPSC and LPSC / 1-undecanethiol mixtures after exposure to air from day 1 to day 7 are shown. [Figure 3f] The results of ionic conductivity measurements for untreated LPSC and LPSC / 1-undecanethiol mixtures after exposure to air from day 1 to day 7 are shown. [Figure 3g] The electrochemical impedance spectroscopy results comparing untreated LPSCs and 1-undecanethiol coated LPSCs after 1 day of exposure to air are shown. [Figure 4a] The 31P spin-echo ss-NMR spectra collected from untreated LPSC samples, pure LPSC samples exposed to ambient air for varying durations, and 1-undecanethiol (thiol) coated LPSC samples are shown. "Wet" and "dry" samples are shown as (wet) LPSC samples exposed to 1-undecanethiol solution and (dry) LPSC samples subsequently dried. [Figure 4b]The 1H spin-echo NMR spectra collected from pure 1-undecanethiol solution, wet-coated LPSCs, and subsequently dried LPSC samples are shown. The 1H resonances of the 11-undecanethiol spectra and their corresponding positions within the molecule are indicated in the upper left corner as (a~f). The resonances of pure 1-undecanethiol that shift in the coated samples are shown with a red dotted line at the original position and a black dotted line with an asterisk letter label at the final position. In both panels, the spectra have been scaled to have the same maximum intensity. All spectra were obtained at 18.8T under 60kHz magic-angle spinning (MAS). [Figure 5] The bulk and grain boundary conductivity results for LPSC and LPSC / 1-undecanethiol mixtures after exposure to air from day 1 to day 7 are shown. [Figure 6a] This shows a symmetrical cycle test of 15 hours at 0.1 mA / cm2 for an untreated LPSC cycle. [Figure 6b] This shows a symmetrical cycle test of LPSC / 1-undecanethiol mixture at 0.1 mA / cm2 for 15 hours. [Figure 6c] The images show LiNi0.8Co0.1Mn0.1O2(NCM811)|LPSCl|LiIn all-solid-state full cells assembled using LPSCs (Figures 6c and 6e) or 1-undecanethiol-coated LPSCs (Figures 6d and 6f). Due to the organic coating protection, both cells exhibit similar second-cycle charge capacity and second-cycle Coulomb efficiency (CE) (Figures 6c and 6d). The LPSCl fuel cells maintain similar capacity and cycle retention rates even after 15 cycles, with discharge capacities of 132.9 mAh / g for LPSCs (Figure 6e) and 133.9 mAh / g for 1-undecanethiol-coated LPSCs (Figure 6f). These observations demonstrate the suspension and strong protective effect of 1-undecanethiol on LPSCs when exposed to air. [Figure 6d]The images show LiNi0.8Co0.1Mn0.1O2(NCM811)|LPSCl|LiIn all-solid-state full cells assembled using LPSCs (Figures 6c and 6e) or 1-undecanethiol-coated LPSCs (Figures 6d and 6f). Due to the organic coating protection, both cells exhibit similar second-cycle charge capacity and second-cycle Coulomb efficiency (CE) (Figures 6c and 6d). The LPSCl fuel cells maintain similar capacity and cycle retention rates even after 15 cycles, with discharge capacities of 132.9 mAh / g for LPSCs (Figure 6e) and 133.9 mAh / g for 1-undecanethiol-coated LPSCs (Figure 6f). These observations demonstrate the suspension and strong protective effect of 1-undecanethiol on LPSCs when exposed to air. [Figure 6e] The images show LiNi0.8Co0.1Mn0.1O2(NCM811)|LPSCl|LiIn all-solid-state full cells assembled using LPSCs (Figures 6c and 6e) or 1-undecanethiol-coated LPSCs (Figures 6d and 6f). Due to the organic coating protection, both cells exhibit similar second-cycle charge capacity and second-cycle Coulomb efficiency (CE) (Figures 6c and 6d). The LPSCl fuel cells maintain similar capacity and cycle retention rates even after 15 cycles, with discharge capacities of 132.9 mAh / g for LPSCs (Figure 6e) and 133.9 mAh / g for 1-undecanethiol-coated LPSCs (Figure 6f). These observations demonstrate the suspension and strong protective effect of 1-undecanethiol on LPSCs when exposed to air. [Figure 6f]The images show LiNi0.8Co0.1Mn0.1O2(NCM811)|LPSCl|LiIn all-solid-state full cells assembled using LPSCs (Figures 6c and 6e) or 1-undecanethiol-coated LPSCs (Figures 6d and 6f). Due to the organic coating protection, both cells exhibit similar second-cycle charge capacity and second-cycle Coulomb efficiency (CE) (Figures 6c and 6d). The LPSCl fuel cells maintain similar capacity and cycle retention rates even after 15 cycles, with discharge capacities of 132.9 mAh / g for LPSCs (Figure 6e) and 133.9 mAh / g for 1-undecanethiol-coated LPSCs (Figure 6f). These observations demonstrate the suspension and strong protective effect of 1-undecanethiol on LPSCs when exposed to air. [Figure 7] This shows a comparison of critical current density and lifetime performance between untreated LPSC and LPSC / 1-undecanethiol mixture. [Figure 8] The 1H NMR spectra collected from pure 1-undecanethiol solution, wet-coated LPSCs, and subsequently dried LPSC samples are shown. [Figure 9a] This is Raman spectroscopy of an untreated pure SH solution and pure SH solutions exposed to 33% RH air for 1, 2, and 3 days (represented as SH 1D air, SH 2D air, and SH 3D air, respectively). [Figure 9b] These are the 1H liquid NMR spectra of an untreated pure SH solution and a pure SH solution exposed to 33% RH air for 1, 2, and 3 days (denoted as SH 1D air, SH 2D air, and SH 3D air, respectively). [Figure 10a] This relates to the chemical compatibility between the SH surface modifier and LPSC. Figure 10a shows the calculated adsorption energies of undecane (CH) and SH on the LPSC surface. [Figure 10b]Figure 10b shows the 1H spin-echo NMR spectra collected at 18.8 T from pure SH solution and SH@LPSC samples. The SH@LPSC spectra were acquired at a magic angle spinning (MAS) rate of 60 kHz. The 1H resonances in the SH@LPSC spectra and their intramolecular corresponding positions are indicated in the upper left corner as (a-f). The positions of the 1H resonances associated with SH molecules in the pure SH solution and SH@LPSC samples are indicated by red dotted lines and black dotted lines / asterisks, respectively. [Figure 10c] Figures 10c and 10d show the XPS spectra of S 2p (Figure 10c) and P 2p (Figure 10d) collected from LPSC and SH@LPSC, respectively. [Figure 10d] Figures 10c and 10d show the XPS spectra of S 2p (Figure 10c) and P 2p (Figure 10d) collected from LPSC and SH@LPSC, respectively. [Figure 10e] Figures 10e and 10f are Cryo-TEM images of LPSC (Figure 10e) and SH@LPSC (Figure 10f), with the latter visualizing the modified layer on the LPSC surface in SH@LPSC. [Figure 10f] Figures 10e and 10f are Cryo-TEM images of LPSC (Figure 10e) and SH@LPSC (Figure 10f), with the latter visualizing the modified layer on the LPSC surface in SH@LPSC. [Figure 10g] Figure 10g shows the Nyquist plot of LPSC and SH@LPSC pellets sandwiched between two titanium rods. [Figure 11] The following describes the synthesis process for surface-modified electrolytes, including the sequence below: LPSC and SH are mixed using Thinky via planetary centrifugal mixing, and the mixture is either exposed to air or vacuum-dried at 80°C for 2 hours without exposure to remove residual absorbents, followed by structural characterization. [Figure 12] This is Rietveld smelting using an XRD pattern obtained with SH@LPSC without exposure to air. [Figure 13]These are 1H spin-echo NMR spectra collected from pure LPSC after vacuum drying at 80°C for 2 hours, SH@LPSC after vacuum drying at 80°C for 2 hours, and SH@LPSC after vacuum drying at 80°C for 2 hours and further heat treatment at 300°C for 3 hours. All spectra were obtained at 18.8T with a MAS rate of 20kHz. Spectra were scaled to have the same number of scans and total sample mass. All other measurement conditions were the same, and a recycle delay of 5*T1 was used. The inserted table records the weight percentage of SH in the dried SH@LPSC samples, determined from the fitting and integration of the 1H NMR signals in the spectra. Although the signal from the SH surface modifier dominates the 1H spectra collected from SH@LPSC, only a very small 1H signal is generated from the LPSC itself, so the SH residues only represent a small mass fraction of the sample. Some of the LPSC-specific 1H signals (see spectra obtained from untreated LPSCs) disappear during heat treatment at 300°C. In thiol quantification, the 1H signal from the untreated material is subtracted from the total signal intensity to separate the contribution from SH. When this is done for a sample heated at 300°C, a negative signal intensity is obtained, indicating that some of the protons in the untreated LPSC are released from the sample during heating at 300°C. [Figure 14] Representative fittings obtained from 1H quantification of SH residue in SH@LPSC samples are shown. All spectra were obtained at 18.8T with a MAS velocity of 20kHz. T2* measurements were performed to fit the attenuation of each component and correct for the disappearance signal during the 50μs echo delay. [Figure 15](a) to (g) show evaluations of LPSC and SH@LPSC exposed to humid ambient air. (a) Schematic diagram of a home-made setup for controlled exposure to humid air, including a thermohydrometer sensor to track changes in relative humidity in a sealed container. (b) XRD patterns collected from LPSC and SH@LPSC exposed to humid air for up to 3 days. (c) Raman spectra of LPSC and SH@LPSC after 1 day and 3 days of exposure to humid air. (d) to (e) Ionic conductivity of LPSC and SH@LPSC as a function of air exposure time and relative humidity. (f) Comparison of ionic conductivity as a function of humid air exposure time, highlighting the far superior stability of SH@LPSC SSE observed during exposure times up to two orders of magnitude longer. (g) Comparison of ionic conductivity loss rates. When normalized by exposure duration, the dramatic improvement provided by SH is also evident. [Figure 16] This shows the moisture absorption of LPSC and SH@LPSC samples exposed to 33%RH air. (a) quantifies the moisture absorption of LPSC and SH@LPSC samples as a function of time by the decrease in relative humidity inside the container. The moisture absorption rate in (b), i.e., the first derivative of the curve in (a), indicates that the lower moisture absorption rate of SH@LPSC indicates that its moisture stability is better than that of pure LPSC. [Figure 17] The complete XRD patterns are shown from LPSC and SH@LPSC samples exposed to air at 33% RH for 5 hours to 3 days. [Figure 18] The ionic conductivity of 200 mg of LPSC and SH@LPSC (LPSC 200 mg and SH 40 mg) is shown as a function of air exposure time and relative humidity. [Figure 19] (a) to (c) show the analysis of material degradation under moisture exposure. (a) to (b) show XPS, and (c) shows the 31P spin-echo solid-state NMR spectra collected by LPSC and SH@LPSC after 1 day or 3 days of air exposure. Solid-state NMR spectra were obtained at 18.8 T and a MAS rate of 60 kHz. [Figure 20]The 6Li spin-echo ss-NMR spectra collected from LPSC and SH@LPSC samples exposed to air for 0 to 3 days at 33% RH are shown. The spectra were obtained at 18.8 T under 20 kHz magic-angle spinning. [Figure 21] The 1H spin-echo ss-NMR spectra collected from SH@LPSC and SH@LPSC samples exposed to air at 33% RH for 1 day are shown. The spectra were obtained at 18.8 T under magic-angle spinning at 10 kHz. [Figure 22] The 6Li spin echo ss-NMR spectra of LPSC and CH@LPSC under air exposure at 33% RH humidity from day 0 to day 3 are shown. All spectra were obtained at 18.8 T under a MAS velocity of 20 kHz. [Figure 23] The 31P spin-echo ss-NMR spectra of LPSC and CH@LPSC under air exposure at 33% RH humidity from day 0 to day 3 are shown. All spectra were obtained at 18.8 T under a MAS velocity of 60 kHz. [Figure 24] The critical current densities of Li / Li symmetric cells in (a) LPSC, (b) SH@LPSC 1D air, and (c) LPSC 1D air at room temperature are shown. [Figure 25] The electrochemical performance of LPSC and SH@LPSC samples after 1 day of exposure to 33%RH air is shown. (a) is the voltage profile at 60°C and 0.1°C rates for the NCM811 composite|LPSC|LPSC 1D air|Li0.5In cell, and (c) is the voltage profile for the NCM811 composite|LPSC|SH@LPSC 1D air|Li0.5In cell. (b) and (d) are the 50-cycle capacity retention rates for the cells shown in (a) and (c), respectively. [Figure 26] (a) shows the voltage profile of the NCM811 composite|LPSC|Li0.5In cell during the first 5 cycles, and (b) shows the long-term cycle performance of the NCM811 composite|LPSC|Li0.5In. [Figure 27]The 300°C heating step shows that all SH residues are completely removed. (a) is the XRD pattern, and (b) is the Nyquist plot of pellets sandwiched between two titanium rods of LPSC, SH@LPSC vacuum-dried at 80°C for 2 hours, and SH@LPSC that was vacuum-dried at 80°C for 2 hours and then heated at 300°C for 3 hours, respectively. [Modes for carrying out the invention]

[0047] The present disclosure is described in detail below. It should be understood that terms or words used herein and in the appended claims should not be interpreted in their general or dictionary sense, but rather in terms of meaning and concepts consistent with the technical idea of ​​the present disclosure, based on the principle that the inventor may appropriately define terms for the best possible explanation. Accordingly, it should be understood that the aspects of the present disclosure described herein and the elements shown in the drawings are merely aspects of the present disclosure and do not fully represent the technical idea of ​​the present disclosure, and that other equivalents and variations may exist at the time of filing. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally known to those skilled in the art. If there are multiple definitions for a term herein, the definition provided herein shall prevail.

[0048] Unless otherwise specified, all percentages, portions, and proportions in this disclosure are based on weight.

[0049] Unless otherwise noted, the numerical parameters described in the following specification and the attached claims are approximations, which may vary depending on the desired properties sought to be obtained in accordance with the aspects of this disclosure. Wherever a numerical range with lower and upper limits is disclosed, any numerical values ​​and any inclusions within that range are specifically disclosed. In particular, all value ranges disclosed in this application (in the form of "approximately A to approximately B," or correspondingly "approximately a to b," or correspondingly "approximately ab") should be understood to describe all numbers and ranges that fall within a broader value range.

[0050] In this specification, compositions and methods are described using the term “containing” various components or steps, but such compositions and methods may also “essentially consist of” or “consist of” various components and steps. As used herein, the term “containing” identifies the presence of the elements mentioned, but does not exclude the presence or addition of one or more other elements unless explicitly stated otherwise in the context.

[0051] In this specification, the terms “about” and “substantially” are used to mean, in terms of or approximately, the numerical value of any manufacturing and material tolerances specific to the circumstances described, and, where exact or absolute numerical values ​​are mentioned to aid in understanding this disclosure, they are used to prevent unscrupulous infringers from unfairly obtaining the benefits of this disclosure. The terms “about” and “approximately” used with numerical variables generally mean the value of the variable in question, and all values ​​of the variable within the experimental error (e.g., a 95% confidence interval for the mean), or within ±10% of a specified value, or within a wider range. Unless otherwise expressly stated, all numerical values ​​in this specification and related claims, such as the amount of components used, properties like molecular weight, reaction conditions, etc., should be understood to be modifiable with the term “about.”

[0052] As used herein, “A and / or B” refers to “A or B, or all of these.”

[0053] One aspect of this disclosure relates to a solid-state battery comprising a solid electrolyte material as the electrolyte. Specific examples of solid-state batteries include any type of primary battery, secondary battery, fuel cell, solar cell, or capacitor such as a supercapacitor. In particular, secondary batteries are specifically lithium-ion secondary batteries.

[0054] In one aspect of this disclosure, the solid-state battery according to this disclosure includes a negative electrode, a positive electrode, and a solid electrolyte interposed between the negative and positive electrodes. The configuration and effects of this disclosure will be described in detail below.

[0055] In this disclosure, the solid electrolyte composition comprises a sulfide-containing solid electrolyte material having an organic coating. In one embodiment, long-chain thiols can be used as the organic coating. According to an embodiment of this disclosure, the coating contains hydrophobic chains which form a hydrophobic barrier and protect the sulfide-containing solid electrolyte material from air, water, and / or ambient conditions.

[0056] As described above, sulfide-containing solid electrolytes are highly sensitive to nucleophilic attack from polar organic solvents. Many common solvents used in conventional liquid lithium-ion batteries are not suitable for use with SSEs. In one embodiment, surface molecular engineering enables the processing of sulfide solid electrolytes in humid ambient air.

[0057] For the purposes of this disclosure, any suitable sulfide-containing electrolyte material can be used. The term "sulfide-based electrolyte" as used herein refers to an ion (e.g., Li + This refers to an electrolyte containing an inorganic substance that conducts sulfide and is suitable for electrically insulating the positive and negative electrodes of an electrochemical cell. An example of a sulfide-containing electrolyte is described in the literature [Shaojie Chen et al., “Sulfide solid electrolytes for all-solid-state lithium batteries: Structure, conductivity, stability and application,” Energy Storage Materials, Volume 14, Pages 58-74 (September 2018)], which is expressly incorporated herein by reference in its entirety.

[0058] For example, many sulfide-containing electrolyte materials are (~10 -2 S cm -1 It is particularly attractive due to its high degree of superionic conductivity and deformability. In particular, Li3P7S 11 Li 10 GeP2S 12Na3PS4 and Li6PS5Cl have been reported to exhibit high ionic conductivity; some even exhibit conductivity close to that of liquid electrolytes. According to aspects of this disclosure, sulfide solid electrolyte materials also provide a low Young's modulus, which is beneficial for creating favorable interfacial contact with electrode materials by simple cold pressing at room temperature.

[0059] According to aspects of this disclosure, the sulfide-containing solid electrolyte contains sulfur (S) and a metal belonging to Group I or Group II of the periodic table, for example, Li + It can have an ionic conductivity of 1 × 10. Furthermore, in one embodiment of the present disclosure, the selected solid electrolyte is 1 × 10 -5 S / cm, or according to certain aspects of this disclosure, 1 × 10 -3 It has an ionic conductivity of S / cm or higher.

[0060] Non-limiting examples of sulfide-containing solid electrolytes include Li-PS-based glass, Li-PS-based glass ceramics, and argyrodite-based sulfide-containing solid electrolytes.

[0061] Non-restrictive examples of sulfide-containing solid electrolytes include at least one of the following: xLi2S-yP2S5, Li2S-LiI-P2S5, Li2S-LiI-Li2O-P2S5, Li2S-LiBr-P2S5, Li2S-Li2O-P2S5, Li2S-Li3PO4-P2S5, Li2S-P2S5-P2O5, Li2S-P2S5-SiS2, Li2S-P2S5-SnS, Li2S-P2S5-Al2S3, Li2S-GeS2 or Li2S-GeS2-ZnS, and Li6PS5X (where X = at least one of Cl, Br, and I).

[0062] In embodiments of this disclosure, the sulfide-containing solid electrolyte may include at least one selected from LPS-based glass or glass ceramic such as xLi2S-yP2S5 and argyrodite-based sulfide-containing solid electrolytes (Li6PS5X; X=Cl, Br, I).

[0063] Sulfide-containing solid electrolyte materials are processed to form a coating on their surface. Sulfur or leaving groups are thought to react with sulfur in the electrolyte material, either interacting non-covalently or forming covalent bonds, such as sulfide or disulfide bonds.

[0064] Sulfur in organic compounds can adhere to the surface of solid electrolyte materials (for example, perhaps forming a disulfide bond or sulfide bond at one end), and hydrophobic tails are arranged to surround the electrolyte material. This hydrophobic layer forms a barrier against water and protects the electrolyte material.

[0065] To form an organic coating, a sulfide-containing solid electrolyte material can be combined with at least one compound selected from the compounds of chemical formulas 1 and 2 below: [Chemical formula 1] RA [Chemical formula 2] R-A'-R In the above formula, A is an -SH group, an isocyanate, an amine, or a suitable leaving group (e.g., triethoxysilyl or trimethoxysilyl); A' is an -S- or -SS- moiety; and each R is independently a substituted or unsubstituted C3-C20 alkyl group.

[0066] In certain embodiments, each R group is independently selected so that the compound of chemical formula 1 or chemical formula 2 is liquid. According to certain embodiments of this disclosure, the total number of carbon atoms (including the chain and substituents) may be 6 to 16 carbon atoms, or, according to certain embodiments of this disclosure, 6 to 12 carbon atoms, 8 to 12 carbon atoms, or 10 to 12 carbon atoms. The compound of chemical formula 1 may have a total of 6 carbon atoms, 7 carbon atoms, 8 carbon atoms, 9 carbon atoms, 10 carbon atoms, 11 carbon atoms, 12 carbon atoms, 13 carbon atoms, 14 carbon atoms, 15 carbon atoms, 16 carbon atoms, 17 carbon atoms, 18 carbon atoms, 19 carbon atoms, or 20 carbon atoms. If the total number of carbon atoms is too low, the compound may be too volatile to be usable. If the total number of carbon atoms is too high, the compound may not be liquid. Accordingly, according to certain embodiments of this disclosure, the total number of carbon atoms and the substituents and main chain can be adjusted as needed so that the compound is liquid.

[0067] Each R group is independently a substituted or unsubstituted C3-C20 alkyl group, which includes, but is not limited to, substituted or unsubstituted n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, isopentyl, n-hexyl, isohexyl, sec-hexyl, tert-hexyl, n-heptyl, isoheptyl, sec-heptyl, tert-heptyl, n-octyl, isooctyl, sec-octyl, tert-octyl, n-nonyl, isononyl, sec-nonyl, tert-nonyl, n-decyl, isodecyl, sec-decyl, tert-decyl, n-undecyl, isoundecyl, sec-undecyl, tert-undecyl, n-dodecyl, isododecyl, sec-dodecyl, tert-dodecyl, etc.

[0068] The R group may be substituted with one or more groups, including but not limited to esters, ketones, halogens (fluorine, chlorine, bromine), and / or one or more C3-C20 alkyl groups (e.g., C3-C8 alkyl groups). In some embodiments, the R group may be substituted with aryl groups (e.g., phenyl) or heteroaryl groups (e.g., five-membered or six-membered rings, including but not limited to pyridine, pyrrole, furan, or thiophene).

[0069] The term "leaving group" can be understood as defined by IUPAC and may, for example, be an atom or group of atoms that detaches from the major or residual portion of a substrate during or at the basic step of a reaction. For example, a leaving group may be a fragment that detaches along with a pair of electrons in heterolytic bond cleavage. In certain embodiments, a leaving group may be an anion or neutral species that detaches from a neutral or cationic substrate. Suitable leaving groups that are compatible with solid electrolyte materials can be used.

[0070] In some embodiments, the A group may be a "triethoxysilyl" moiety (e.g., derived from HSi(OC2H5)3) or a "trimethoxysilyl" moiety (e.g., derived from HSi(OCH3)3).

[0071] The term "thiol" can be understood as an organosulfur compound in the R-SH form, where R represents an alkyl or other organic substituent.

[0072] The term "isocyanate" can be understood as a functional group having the formula RN=C=O, where R may be an alkyl or aryl group.

[0073] The term "amine" can be understood as a compound or functional group containing a basic nitrogen atom with a lone pair of electrons. Amines are formally derivatives of ammonia (NH3) in which one or more hydrogen atoms are substituted with substituents such as alkyl or aryl groups (e.g., alkylamines and arylamines). The substituent -NH2 is called the amino group. In certain embodiments, amines may include primary amines, secondary amines, and / or tertiary amines. In certain embodiments, the amino group can be further converted into useful leaving groups, for example, by conversion to ammonium salts, aryl(sulfonyl)amino groups, etc.

[0074] In some embodiments, the sulfide-containing solid electrolyte material and the compound of chemical formula 1 can be combined in a weight ratio of about 1:1 to 25:1, or, according to some embodiments, in a weight ratio of about 1:1 to 10:1, about 1:1 to 5:1, or about 1:1.

[0075] Since sulfide-containing materials are sensitive to air and moisture and can decompose to produce toxic gases such as H2S, according to certain aspects of this disclosure, all synthesis and testing steps are carried out in a glove box filled with argon (e.g., MBraun MB 200B, H2O < 0.5 ppm, O2 < 5.0 ppm). Selectively, the reaction mixture of the sulfide-containing solid electrolyte material and the compound of chemical formula 1 may further contain a suitable solvent to aid dispersion.

[0076] Suitable reaction conditions can be used. In one embodiment, the reaction temperature may be room temperature to about 50°C. In some embodiments, the reaction temperature may be about 15°C to about 40°C, about 20°C to about 40°C, or about 25°C to about 40°C.

[0077] In one embodiment, the reaction time may be about 30 minutes. In some embodiments, the reaction time may be about 1 hour to about 8 hours, and in some embodiments, it may be about 2 hours to about 7 hours, or about 3 hours to about 5 hours.

[0078] The progress of the reaction can be monitored using any suitable technique, which includes, but is not limited to, suitable techniques such as X-ray photoelectron spectroscopy or nuclear magnetic resonance (NMR).

[0079] After the reaction is complete, the coated solid electrolyte material can be dried under any suitable conditions. In one embodiment, the drying temperature may be about 30°C to about 100°C, about 40°C to about 100°C, or about 50°C to about 100°C. According to some aspects of this disclosure, drying is carried out under vacuum conditions. In one embodiment, the drying time may be 30 minutes or more. In other embodiments, the drying time may be 1 hour or more, and according to some embodiments, 2 hours or more, 8 hours or more, or 12 hours or more.

[0080] In this disclosure, the average particle size of the sulfide-containing solid electrolyte material can be adjusted to a range suitable for solid-state batteries. In some embodiments of this disclosure, the solid electrolyte may have an average particle size of 0.1 μm to 50 μm.

[0081] In some aspects of this disclosure, the solid electrolyte membrane can be manufactured by any suitable method.

[0082] For example, after coating a solid electrolyte material, it can be optionally combined and mixed with other components to obtain a homogeneous mixture. This mixture can then be added to a predetermined organic solvent and dispersed to produce a slurry. The slurry can be applied to a release plate and then dried to form a sheet. If necessary, the resulting sheet can be pressurized to obtain a solid electrolyte membrane.

[0083] The thickness of the solid electrolyte layer formed by lithium-tin-metal-sulfide compounds varies greatly depending on the structure of the all-solid-state battery. For example, in some embodiments, it may be between 0.1 μm and 1 mm, and in further embodiments, it may be between 1 μm and 100 μm. In some embodiments, the solid electrolyte has high lithium ion conductivity, and in some embodiments, the lithium ion conductivity at room temperature is, for example, 1 × 10⁻⁶.-4 It is S / cm or higher.

[0084] In one embodiment, the solid electrolyte may further include solid electrolytes commonly used in all-solid-state batteries. For example, an inorganic solid electrolyte or an organic solid electrolyte may be used.

[0085] In the case of inorganic solid electrolytes, ceramic materials, crystalline materials, or amorphous materials can be used, and thio-LISICON(Li 3.25 Ge 0.25 P 0.75 S4), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li2S-P2S5, Li3PS4, Li7P3S 11 , Li2O-B2O3, Li2O-B2O3-P2O5, Li2O-V2O5-SiO2, Li2O-B2O3, Li3PO4, Li2O-Li2WO4-B2O3, LiPON, LiBON, Li2O-SiO2, LiI, Li3N, Li5La3Ta2O 12 Li7La3Zr2O 12 Li6BaLa2Ta2O 12 Li3PO (4-3 / 2w) Nw (where w < 1), and Li 3.6 Si 0.6 P 0.4 Inorganic solid electrolytes such as O4 can be used.

[0086] Examples of organic solid electrolytes include those produced by mixing lithium salts with polymer materials such as polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate ester polymers, edation lysine, polyester sulfide, polyvinyl alcohol, and polyvinylidene fluoride. In this case, these can be used individually or in combination of at least two.

[0087] The coated sulfide-containing electrolyte material can be used as a solid electrolyte for all-solid-state batteries. All-solid-state batteries include a positive electrode and a negative electrode, with a solid electrolyte interposed between them.

[0088] On the other hand, the positive and negative electrodes of the all-solid-state battery according to the embodiments of this disclosure are not particularly limited, and any suitable ones known in the art can be used.

[0089] The all-solid-state batteries proposed in the embodiments of this disclosure define the configuration of the solid electrolyte as described above, and the other components constituting the battery, namely the positive electrode and the negative electrode, are not particularly limited in this disclosure and are subject to the following description.

[0090] In one embodiment, the negative electrode of the all-solid-state battery may consist of lithium metal alone, or a negative electrode active material may be laminated on a negative electrode current collector.

[0091] The negative electrode current collector is not particularly limited as long as it does not cause any chemical changes in the all-solid-state battery and is conductive. For example, copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel whose surface is treated with carbon, nickel, titanium, silver, etc., or aluminum-cadmium alloy can be used. In addition, the negative electrode current collector, like the positive electrode current collector, can take various forms such as films, sheets, foils, nets, porous materials, foams, and nonwoven fabrics with fine irregularities formed on the surface.

[0092] The negative electrode active material may be any selected from the group consisting of lithium metal, lithium alloy, lithium metal composite oxide, lithium-containing titanium composite oxide (LTO), and combinations thereof. In this case, the lithium alloy may be an alloy of lithium and at least one metal selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn. The lithium metal composite oxide may be an oxide (MeO) of lithium and one metal (Me) selected from the group consisting of Si, Sn, Zn, Mg, Cd, Ce, Ni, and Fe. xIt may also be, for example, LixFe2O3 (0 ≦ x ≦ 1) or LixWO2 (0 ≦ x ≦ 1).

[0093] Also, the negative electrode active material is Sn x Me 1-x Me’ y O z (Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, elements of Groups 1, 2 and 3 of the periodic table, halogen; 0 < x = 1; 1 = y = 3; 1 = z = 8) such as metal composite oxides; oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5; and carbon-based negative electrode active materials such as crystalline carbon, amorphous carbon or carbon composites, and these can be used alone or in combination of two or more.

[0094] In some aspects of the present disclosure, the positive electrode can include a positive electrode active material layer containing a positive electrode active material, a positive electrode conductive material, and a solid electrolyte. The positive electrode active material layer can further include a binder resin for the positive electrode if necessary. Also, the positive electrode can include a current collector as needed, and the positive electrode active material layer can be located on at least one surface of the current collector.

[0095] In some aspects of the present disclosure, the positive electrode active material is lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), the formula Li 1+x Mn 2-x O4 (x is 0 to 0.33, for example, LiMn2O4), LiMnO3, LiMn2O3, LiMnO2, lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiV2O4, V2O5, Cu2V2O7, the formula LiNi 1-x M x O2 (M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, 0 < x < 1) nickel-site lithium nickel oxide represented by, for example, LiNi 1-z (Co,Mn,Al) z O2 (0 < z < 1); the formula LiMn 2-x M xA lithium manganese composite oxide represented by O4 (M = Co, Ni, Fe, Cr, Zn, or Ta, x = 0.01 to 1), for example, LiMn 1.5 Ni 0.5 O4 or Li2Mn3MO8 (M = Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which Li in the formula is partially substituted with an alkaline earth metal ion; a disulfide compound; it may contain at least one of Fe2(MoO4)3 and lithium iron phosphate (LiFePO4). In some embodiments of the present disclosure, the lithium iron phosphate may have all or at least a part of the surface of the active material particles coated with a carbon material to improve conductivity.

[0096] According to an aspect of the present disclosure, the positive electrode active material may include lithium nickel cobalt manganese oxide (for example, Li(Ni,Co,Mn)O2, LiNi 1-z (Co,Mn,Al) z O2 (0 < z < 1)), lithium iron phosphate (for example, LiFePO4 / C), lithium nickel manganese spinel (for example, LiNi 0.5 Mn 1.5 O4), lithium nickel cobalt aluminum oxide (for example, Li(Ni,Co,Al)O2), lithium manganese oxide (for example, LiMn2O4), and lithium cobalt oxide (for example, LiCoO2).

[0097] According to some aspects of the present disclosure, the positive electrode active material may include a lithium transition metal composite oxide, and the transition metal may include at least one of Co, Mn, Ni, and Al.

[0098] In some embodiments of the present disclosure, the lithium transition metal composite oxide may include at least one of the compounds represented by the following formula 1.

[0099] [Formula 1] Li x Ni a Co b Mn c M z O In the formula 1, 0.5 ≦ x ≦ 1.5, 0 < a ≦ 1, 0 ≦ b < 1, 0 ≦ c < 1, 0 ≦ z < 1, 1.5 < y < 5, a + b + c + z is 1 or less, and M may contain at least one selected from Al, Cu, Fe, Mg, and B.

[0100] In some embodiments of the present disclosure, the positive electrode active material includes a positive electrode active material having a high Ni content of 0.5 or more, and specific examples thereof include LiNi 0.8 Co 0.1 Mn 0.1 O2 may be included.

[0101] In some embodiments of the present disclosure, the positive electrode conductive material may be at least one conductive material selected from the group consisting of, for example, graphite, carbon black, carbon fiber or metal fiber, metal powder, conductive whisker, conductive metal oxide, activated carbon, and polyphenylene derivative. More specifically, the positive electrode conductive material may be at least one conductive material selected from the group consisting of natural graphite, artificial graphite, super - p, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, denka black, aluminum powder, nickel powder, zinc oxide, potassium titanate, and titanium oxide.

[0102] The current collector is not limited to a specific type and may include those that do not cause a chemical change in the battery and have high conductivity (for example, stainless steel, copper, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel whose surface is treated with carbon, nickel, titanium, or silver).

[0103] The positive electrode binder resin may include, but is not limited to, polymers commonly used for electrodes in the art. Examples of binder resins include, but are not limited to, polyvinylidene fluoride, polyvinylidene-co-hexafluoropropylene, polyvinylidene-co-trichloroethylene, polymethyl methacrylate, polyethylhexyl acrylate, polybutyl acrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethylcellulose, cyanoethyl sucrose, pullulan, and carboxymethylcellulose.

[0104] In some embodiments of this disclosure, the solid electrolyte contained in the positive electrode may include at least one selected from polymer-based solid electrolytes, oxide-based solid electrolytes, and sulfide-containing solid electrolytes. In some embodiments of this disclosure, the positive electrode active material may include a sulfide-containing solid electrolyte as described in the Solid Electrolyte Membrane section.

[0105] In some aspects of this disclosure, the positive electrode active material is included in the positive electrode in an amount of 50% by weight or more, based on 100% by weight of the positive electrode active material layer. Furthermore, according to aspects of this disclosure, the solid electrolyte is included in the positive electrode in an amount of 10% to 40% by weight, based on 100% by weight of the positive electrode active material layer.

[0106] On the other hand, in some embodiments of this disclosure, the positive electrode is 5 mAh / cm². 2 More than 6mAh / cm 2 Above 10mAh / cm², or 10mAh / cm² 2 The above load capacity (per electrode area) can be achieved. In the battery according to this disclosure, when a high-load positive electrode is applied, the battery can be operated at an electrochemically stable level.

[0107] On the other hand, in some embodiments of this disclosure, the positive electrode active material layer can be obtained by preparing a slurry by adding the positive electrode active material, conductive material, binder resin, and solid electrolyte to a suitable solvent and casting the slurry, or by a manufacturing method using a dry mixing process without a solvent. On the other hand, in some embodiments of this disclosure, it is possible to achieve uniform mixing of the positive electrode active material in the positive electrode and obtain a high-load positive electrode. In this embodiment, the positive electrode is obtained by a dry mixing process without the use of a solvent.

[0108] A method for producing a positive electrode active material layer by a dry mixing method can be described, for example, as follows: First, the positive electrode material, including the positive electrode active material, a conductive material, and a binder resin, is placed in a mixing apparatus and mixed by a mechanical method to obtain a mixture. The mixing apparatus includes, and is not limited to, any type of apparatus capable of forming a relatively homogeneous mixed phase, such as a known mixer or agitator. On the other hand, in some embodiments of this disclosure, a heating step may be included to improve the dispersion of solids in the mixing step and to induce a fibrous morphology of the binder resin. In the heating step, the temperature can be appropriately controlled in the range of approximately 30°C to 100°C. Next, the mixture can be extracted into the shape of an electrode (a broad film shape) using an extruder, and the thickness can be adjusted by a pressing step to form a positive electrode active material layer. The positive electrode active material layer can also be applied to an electrode without a current collector, and if necessary, a current collector can be attached to the obtained positive electrode active material layer to produce a positive electrode with a current collector.

[0109] Examples (1) Production of 1-undecanethiol coated Li6PS5Cl Li6PS5Cl (purchased from NEI) was used as received. All samples were handled in a glove box with oxygen and moisture levels below 0.5 ppm. 560 mg of Li6PS5Cl and 112 mg of 1-undecanethiol (Sigma-Aldrich) (weight ratio 5:1) were weighed into 30 mL plastic vials containing zirconium balls, and mixed in a planetary mixer (THINKY TM Spin mixing was performed at 2000 rpm for 20 minutes using ).

[0110] (2) Exposure of the sample to air and drying A 30 mL plastic vial containing a mixture of 560 mg of Li6PS5Cl and 112 mg of 1-undecanethiol from the previous stage was placed in a 16 oz airtight bottle to minimize air exposure. Humidity and temperature were recorded. The samples were exposed for the following exposure times: 1 day (24 hours), 3 days (72 hours), 5 days (120 hours), and 7 days (168 hours). After air exposure, the samples were placed in a vacuum oven to dry any excess solvent and moisture from the material surface. The samples were vacuum-dried at 80°C for 2 hours with a heating gradient of 1°C / min. The samples were then transferred to a glove box for further use.

[0111] (3) NMR characteristic analysis Sample containing 1-undecanethiol coating material 1 H and 31 We investigated using 1P solid-state NMR (ss-NMR) to evaluate the effectiveness of the coating in preventing chemical degradation of LPSCs when exposed to ambient conditions, and to understand the mechanism of interaction between the organic molecules of the coating and the LPSC surface. Because ss-NMR is element-specific and sensitive to both crystalline and amorphous phases, we investigated the interaction within the 1-undecanethiol molecule. 1 H nucleus and LPSC electrolyte 31 It is possible to selectively probe the P nucleus.

[0112] Figure 4a shows the results for untreated (pristine) LPSCs and pure LPSCs and 1-undecanethiol (thiol) coated LPSC samples after exposure to ambient air for the various time periods mentioned. 31 The P ss-NMR spectra are shown. Results obtained from untreated LPSC samples, thiol-coated wet samples, and dry samples. 31 No significant differences were observed between the P spectra, which means that the LPSC bulk structure did not change upon exposure to the coating solution or subsequent exposure to air.

[0113] To establish a baseline for the effects of air exposure on LPS, pure LPSC samples exposed to air for one day were used. 31 P ss-NMR spectra were collected, which are shown in the upper panel of Figure 4a. As illustrated, when exposed to air without coating, the bulk structure of LPSC degrades significantly, similar to that of γ-Li3PS4 in an environment similar to that of POS3. 3- Tetrahedral units and isolated PS4 3- This is reflected in the fact that at 82.9 and 88.7 ppm, which are assigned to the tetrahedron, the broad resonance of the untreated LPSC disappears and a sharp resonance appears. On the other hand, the following was observed when collecting samples from thiol-coated samples exposed to ambient air for one day. 31 The P ss-NMR spectrum was almost identical to that obtained from the untreated sample, indicating that the coating protected the LPSC structure from degradation. This was also observed in the untreated sample after 3 days in air. 31 Most of the P spectral features were preserved. Nevertheless, the resonances at 82.9 and 88.7 ppm and the PS4 isolated in an environment similar to that of β-Li3PS4 were preserved. 3- The onset of degradation is suggested by a third resonance at 86.8 ppm assigned to the tetrahedron. As exposure time increases, the peaks at 82.9 ppm, 86.8 ppm, and 88.7 ppm become larger, and the broadened LPSC resonance almost disappears, indicating the loss of the bulk structure of the LPSC. Interestingly, when the coated LPSC sample is exposed to air, isolated PS4 similar to Li3PS4 is observed, as evidenced by the higher resonance intensities at 86.8 ppm and 88.7 ppm in the coated LPSC sample. 3- It appears that more tetrahedra are formed compared to pure samples.

[0114] Samples were coated with undecane instead of 1-undecanethiol and collected from a sample set exposed to air using the same procedure as described above. 31The P spectrum highlights the role that thiol chain ends play in the protection mechanism of LPSCs. When coated with undecane, which has methyl-terminated groups instead of thiol groups, the LPSC sample was protected after just one day of exposure to air. 31 Significant changes occur in the P resonance. From the above results, it is clearly demonstrated that the thiol coating delays the onset of degradation and preserves the LPSC structure almost completely even after exposure to ambient air for up to 72 hours.

[0115] To investigate the characteristics of the interaction between the organic molecules of the coating and the LPSC surface, and to evaluate the efficiency of the drying stage, a series of thiol-coated LPSC samples were obtained from a pure 1-undecanethiol solution and wet and dry conditions. 1 H ss-NMR spectra (shown in Figure 4b) were collected. In the spectra obtained from the pure undecanethiol solution, six 1 The H resonance can be resolved, and these are the predicted shift and integrated signal intensity from the ACD / HNMR Predictor software package. 1 Based on the agreement between H environment multiplicities, the six components present in the undecanethiol molecule 1 These were assigned to the H local environment (indicated as (a~f)). As shown in Figure 4b, when the 1-undecanethiol solution was mixed with LPSC ("LPSC coated, wet" sample), all of these resonances remained, but the (a) and (b) resonances were shifted downfield (to more positive ppm frequencies). The (a) and (b) resonances were bonded to carbon atoms one and two bonds away from the thiol terminal group, respectively. 1 This corresponds to the H nucleus. In NMR, the isotropic shift of a nucleus depends on the degree of shielding from the static magnetic field provided by the local electron cloud, and therefore differs greatly depending on its binding environment. Thus, the changes in the isotropic shifts of the (a) and (b) resonances suggest that the undecanethiol molecule interacts with or binds to the LPSC surface at its thiol terminus. The downfield shift of the (a) resonance (0.2 ppm) is larger than that of the (b) resonance (0.08 ppm), which is closest to the thiol terminus. 1This is consistent with a larger change in the electron cloud surrounding the H nucleus.

[0116] Thiol group 1 The disappearance of the (d) resonance assigned to H provides additional evidence that the thiol terminus is attached to the LPSC surface; however, because the signal overlaps with the (c) and (e) resonances and the amount of undecanethiol in the "LPSC coated, wet" and "LPSC coated, dry" samples is unknown, it is difficult to reliably evaluate the change in the intensity of the (d) signal. In the (f) resonance, an upfield shift (0.08 ppm) corresponding to the undecanethiol methyl chain terminus is observed. This slight upfield shift is tentatively attributed to weak van der Waals bonding interactions between the methyl terminus of the undecanethiol molecule and the LPSC surface. This assignment is nearly the same upfield when the LPSC is coated with undecane, as shown in Figure 8. 1 This is supported by the observation of the H shift.

[0117] As can be seen from the spectrum in Figure 8, a broad concentration is observed between 0.5 and 1 ppm. 1 H resonance corresponds to protonated impurities in the untreated material. Even after exposing LPSC samples to a 1-undecanethiol solution and drying at 80°C, the coating is not completely removed, which is a strong characteristic collected from "LPSC coated, dry" samples. 1 This is confirmed by the 1H NMR signal. This spectrum contains (a-f) resonances similar to those obtained from the "LPSC coated wet" sample, but an additional broad signal is observed in the 3-3.5 ppm range. This additional signal may be due to the presence of undecanethiol molecules on the surface of the dry LPSC particles with various orientations and restricted movements, resulting in various chemical shifts and signal broadening.

[0118] (4) PXRD characteristic analysis The samples were further characterized using powder XRD ("PXRD") measurement. After coating the adsorbent onto the LPSC, the crystal structure and the change in conductivity (if any) due to EIS were confirmed, and the compatibility of the coating was evaluated.

[0119] As shown in Figures 2a and 3a, the XRD results indicate that the bulk crystal structure remains unchanged even after 1-undecanethiol is coated onto the LPSC. That is, the LPSC has an argyrodite structure. Rietveld refining after exposure to 1-undecanethiol also shows that the argyrodite structure is maintained. There is no change in the bulk crystal structure.

[0120] (5) Raman characterization Raman diffraction was measured using a Bruker at 10°–80° with a scan rate of 2° / min. To prevent exposure to air, the powder was prepared by grinding it in a glove box covered with Kapton tape. Raman spectroscopy was performed using a 532 nm source.

[0121] Using Raman spectroscopy, 424.5 cm⁻¹ -1 The structural evaluation during air exposure was performed by monitoring the change in the peak at 424.5 cm². This peak shifted to lower wavenumbers as the material degraded. Samples exposed for up to 3 days showed no shift in the main peak. These results are consistent with XRD results indicating no change in the bulk structure up to that point. -1 The peak indicates PS4, the core structural component responsible for the excellent ion conductivity of these sulfide solid electrolyte materials. 3- This corresponds to a binding. This binding shift is due to the formation of oxythiophosphate species, but further research is needed to understand the precise speciation.

[0122] (6)XPS characteristics X-ray photoelectron spectroscopy (XPS) was also used to observe the oxidation state or bond transitions after the sample was exposed to air. The main peaks of interest are S 2p and P 2p, as these contain the major characteristic bonds of LPSC (Figures 3d and 3e). Untreated LPSC shows an S 2p signal at 161.5 eV and a P 2p signal at 132.0 eV. The peak at 160.3 eV, which begins to appear after 5 days of air exposure, is where the Li 2S peak should be located, indicating that the LPSC has begun to decompose via hydrolysis. On the other hand, the P 2p peak appearing around 133 eV is consistent with the formation of POxSy oxysulfide. However, since various oxysulfide species generally all appear in that region, it is impossible to identify exactly which species it is. However, the signal at 133.6 eV may indicate that the Li 3PO4 species has also been formed.

[0123] (7) Electrochemical property analysis The samples were characterized using electrochemical impedance spectroscopy (EIS). For ionic conductivity measurements, all materials were cold-pressed into dense pellets at a volume of less than 6 tons. The pellets had a diameter of 13 mm, with a diameter of 470 μm for 100 mg pellets and 1200 μm for 260 mg pellets. The pellets were prepared by pressing the powder with a titanium rod in a PEEK Swagelok die. Titanium served as the shielding electrode. Impedance measurements were performed using a frequency response analyzer (CH Instruments workstation) with an amplitude of 5 mV in the frequency range of 1 MHz to 100 MHz.

[0124] For reference, a conductivity test control experiment was conducted using untreated LPSCs (Figure 3). In the case of untreated LPSCs, the material did not maintain its ionic conductivity beyond one day of exposure to air.

[0125] (8) Cell fabrication and cycleability measurement To evaluate the electrochemical properties of the aforementioned sulfide SSE samples, a 13 mm diameter all-solid-state battery (ASSB) was assembled using a polyaryletherketone (PEEK) mold and a Ti rod. Symmetric cells were fabricated using 100 μm Li metal electrodes at both ends. LPSC, specifically 1-undecanethiol / LPSC (1200 μm) exposed to air for 1 day, was used as the electrolyte. Each full cell contained 3 mg / cm³ of NCM811 (LG Energy Solutions)-LPSC-VGCF cathode composite in a weight ratio of 66:31:3. 2 The cells were fabricated by loading. A LiIn alloy was used as the negative electrode. An untreated LPSC (450 μm) electrolyte layer was placed between the positive electrode and an LPSC coated with 1-undecanethiol and exposed to air. Cell measurements were performed using a LAND multi-channel battery test system. Constant current charge-discharge tests of symmetric cells were performed at room temperature (20-25°C) at 0.1 mA / cm². 2 The tests were conducted at a constant current charge / discharge rate of 0.05C for the first cycle and 0.1C for the second cycle, within a voltage range of 1.9 to 3.65V at temperatures below 60°C.

[0126] A study was conducted to investigate whether LPSCs exposed to air can maintain their function in all-solid-state batteries. Symmetrical cycle tests showed that untreated LPSCs (Figure 6a) exhibited a capacitance of 0.1 mA / cm². 2 It can be seen that a 15-hour cycle is maintained. 1-Undecanethiol-coated LPSCl after 1 day of air exposure (Figure 6b) remained stable even after longer cycles than the untreated sample. Note that the polarization is slightly higher when using 1-Undecanethiol / LPSC exposed to air for 1 day.

[0127] To study cycle stability, LiNi 0.8 Co 0.1 Mn 0.1O2(NCM811)|LPSCl|LiIn all-solid-state full cells were prepared. These were assembled using untreated LPSC or 1-undecanethiol / LPSC exposed to air for 1 day (1D) (Figures 6c-6f). With 1-undecanethiol coating protection, both cells exhibited similar secondary cycle charge capacity and secondary cycle Coulomb efficiency (CE) (Figures 6c and 6d). The LPSCl full cells maintained similar capacity and cycle retention rates even after 15 cycles, with discharge capacities of 132.9 mAh / g for LPSC (Figure 6e) and 133.9 mAh / g for 1D 1-undecanethiol / LPSC (Figure 6f). This observation demonstrates the remarkably strong protective effect of 1-undecanethiol on LPSC when exposed to air.

[0128] The conductivity of 1-undecanethiol coated LPSC is 2.2 mScm. -1 From 1.73 mScm -1 It was shown to decrease slightly. This slight decrease may be due to the introduction of nonconductive foreign matter, and the fact that its effect on ionic conductivity is negligible is highly unusual among polar organic solvents.

[0129] In summary, all XRD, Raman, and XPS results show that the 1-undecanethiol coated LPSC maintains its protective state without damaging its structure or conductivity, even when exposed to air for up to 3 days.

[0130] (9) Chemical compatibility of SH and LPSC To gain insight into the water-repellent capacity of SH during prolonged exposure to air, the interaction between 1-undecanethiol (SH) and water was studied without LPSC. Figure 9a shows the Raman spectra recorded at 300–1900 cm⁻¹ when the SH solution was exposed to 33% RH air for 1, 2, and 3 days to monitor the change in CS stretching frequency. -1 This indicates the area. SH is 639cm -1 Maintaining a CS-bound peak, 450-495 cm -1There is no evidence of SS bond formation, which suggests that SH molecules maintain structural integrity in ambient air. 1 We also collected the 1H nuclear magnetic resonance (NMR) spectrum (shown in Figure 9b), which revealed the six types of NMR present in the SH molecule. 1 Six localized environments 1 It exhibits H resonance. During long-term exposure, 1 The H signal shows a constant isotropic shift, the H2O peak does not appear, and the change in signal intensity is minimal. This suggests that the structure of the SH molecule is maintained without change, and the diffusion of H2O within the SH is very slow.

[0131] Introducing small molecules into the system allows for good maintenance of the ionic conductivity of SSE, unlike previously reported polymer surface modifiers. This protective mechanism is highly effective. SH@LPSC maintained its ionic conductivity of 1 mS cm even after exposure for up to 2 days (33% RH). -1 Maintain the above conditions. After 3 days of exposure to 33% RH, the SH@LPSC powder maintained its original color and crystallinity, while the control material showed a clear discoloration and a rapid decrease in conductivity (Figure 1b).

[0132] (10) Chemical interaction between LPSC and SH To explore the chemical interaction between LPSC and 1-undecanethiol (SH), density functional theory (DFT) calculations were performed on the adsorption energies of undecane (CH) without a thiol head group and SH containing a thiol functional group to the LPSC surface. Figure 10a shows that both organic compounds can be adsorbed on the LPSC surface, but SH shows a much higher surface adsorption tendency (-3.82 eV) compared to CH (-1.172 eV). Furthermore, SH can form SS bonds with LPSC.

[0133] Density functional theory (DFT) calculations were performed using VASP code 49. The exchange-correlation was handled using the PBE (Perdew-Burke-Ernzerhof) function within the GGA (generalized gradient approximation) 50, while the PAW (projector augmented-wave pseudopotential) 51 was applied with a kinetic energy cutoff of 500 eV to account for the extension of electron eigenfunctions. The vacuum thickness was set to 15 Å to minimize interlayer interactions. Brillouin-zone integration was sampled using Γ-centered 3×3×1 Monkhorst-Pack k-points. All atomic positions were set to 1×10⁻¹⁶ energy and force, respectively. -5 The parameters were sufficiently relaxed to reach tolerances of eV and 0.03 eV / Å. To account for long-range interactions, the variance-corrected DFT-D method was used.

[0134] SH-modified LPSCs (SH@LPSCs) were prepared by mixing desired amounts of material using a planetary centrifugal mixer (Figure 11). The mixture was then vacuum-dried at 80°C for 2 hours to remove any unbonded SH remaining on the LPSC surface. The compatibility of SH and LPSCs was evaluated by monitoring the potential changes in the crystal structure and ionic conductivity of the SH@LPSCs. Rietveld refinement of the XRD patterns obtained from the SH@LPSC samples (Figure 12) indicates that the argyrodite structure is preserved. 1H spin-echo NMR spectra (shown in Figure 10b) were collected from pure SH solution and SH@LPSC samples to investigate the characterization of the interaction between SH and the LPSC surface. In the spectra obtained from the SH solution, six 1H resonances could be resolved, which are assigned to six 1H local environments in the SH molecule (indicated as (a~f)). This assignment is based on the predicted 1H shift from the ACD / HNMR Predictor software package, and the observed integrated signal intensity and expected 1H site multiplicity. In SH@LPSC, all SH resonances are still observed, but the (a) and (b) resonances are downfield shifted (at more positive ppm frequencies). The (a) and (b) resonances correspond to 1H nuclei bonded to carbons one and two bonds away from the thiol-terminated group, respectively. In NMR, the isotropic shift of the nuclei is a sensitive probe for local structural changes because it depends on the degree of shielding from the static magnetic field provided by the local electron cloud. Here, the change in the isotropic shift of the (a) and (b) resonances suggests that the SH molecule is bound to the LPSC surface at the thiol terminus. The downfield shift of the (a) resonance (0.2 ppm) is larger than that of the (b) resonance (0.08 ppm), which is consistent with a larger change in the electron cloud around the 1H nucleus closest to the thiol terminus. The apparent disappearance of the (d) resonance assigned to the thiol group 1H in the SH@LPSC spectrum could provide additional evidence of thiol terminus adhesion to the LPSC surface; however, this signal overlaps with the (c) and (e) resonances, and the presence of residual free SH molecules in the SH@LPSC sample makes it difficult to correlate the change in the (d) signal intensity with adhesion chemistry.(f) For the resonance, an upfield shift corresponding to the SH methyl chain terminus is observed (0.08 ppm). This slight upfield shift was tentatively attributed to a weak van der Waals interaction between the methyl terminus of the SH molecule and the LPSC surface. The broad 1H resonance observed between 0.5 and 1 ppm in the SH@LPSC spectrum in Figure 10b is obtained from pure LPSC and is shown in Figure 13. 1 As confirmed by the H spectrum, this corresponds to a protonated impurity in LPSC SSE. When the SH@LPSC sample is subjected to a vacuum drying procedure at 80°C for 2 hours, the same 1 As can be seen from the remaining SH signal in the 1H NMR spectrum (Figure 13), SH residue is not completely removed, and signal integration suggests that the sample contains approximately 4-5 wt% SH. However, if desired, almost all of the SH modifier can be volatilized after further heat treatment at 300°C (Figure 13). More detailed information on the quantification procedure is shown in Figure 13, and a representative fitting of the spectrum is provided in Figure 14.

[0135] Using surface-sensitive XPS analysis, the binding interaction between SH and LPSC was further investigated, and the results are presented in Figures 10c-10d. LPSC and SH@LPSC exhibit PS-derived PS binding at 161.5 eV in the S 2p spectrum and 131.9 eV in the P 2p spectrum. The 160 eV Li-S (Figure 10c) and 133.5 eV PO (Figure 10d) signals for LPSC originate from surface decomposition products such as Li2S and POxSy during LPSC transport. Within SH@LPSC, the increase in intensity of the 160 eV SH peak overlapping with Li-S and the simultaneous decrease in the 133.5 eV PO peak suggest the formation of a thin SH film on the LPSC surface. The increase in intensity of the 164.5 eV SS peak in the SH@LPSC sample (Figure 10c) may be due to sulfur atom bridging. This provides strong evidence that a SS bond was established between the SH molecule and the S atom on the surface of the LPSC. The integrity of the PS bond at 131.9 eV in Figure 10d indicates good compatibility between SH and LPSC. These findings confirm the existence of SS interactions between SH and LPSC and are consistent with DFT calculations and NMR results.

[0136] As shown in Figures 10e to 10f, the Cryo-TEM images of untreated LPSC and SH@LPSC samples reveal the nanoscale distribution of crystalline and amorphous regions. The lattice spacing measured in SH@LPSC (0.182 nm, Figure 10f) is similar to that measured in untreated LPSC (0.185 nm, Figure 10e), indicating that the bulk crystal structure is not altered even with SH modification on the LPSC surface. This observation demonstrates the compatibility of SH and LPSC. The SH@LPSC sample exhibits an amorphous layer approximately 3 nm thick on the LPSC particle surface, which is attributed to SH adsorption.

[0137] The combined bulk and grain boundary resistances of SH@LPSC show a slight increase of 20 to 22 ohms compared to untreated LPSC (Figure 10g). This slight increase may be due to the presence of 4–5 wt% nonconductive SH residue remaining after the 80°C drying procedure. Li ionic conductivity, based on the average of three independent measurements, was 1.8 ± 0.16 mS cm, respectively. -1 and 1.6 ± 0.03 mS cm -1 (The error corresponds to a standard deviation of 1). The fact that the SH surface modifier has only a negligible effect on the conductivity of LPSCs is highly unusual. For example, when sulfide SSEs are exposed to other polar solvents such as diethylene glycol dimethyl ether or propylene carbonate, it is generally observed that the ionic conductivity decreases by about twofold due to nucleophilic attack on the SSE species by electron donors from solvent molecules. In the case of propylene carbonate, the resulting mixture becomes sticky and its ionic conductivity is too low to be measured.

[0138] (11) Effectiveness of protection against moisture To study the chemical stability of LPSC against hydrolysis, LPSC and SH@LPSC were evaluated after exposure to humid ambient air for 5 hours and up to 3 days. Samples are labeled "LPSC Time Air," for example, LPSC 5H air means a sample exposed for 5 hours.

[0139] A 12 mL plastic vial containing a mixture of 600 mg LPSC and 120 mg SH was placed in a 16 oz bottle and exposed to air at room temperature with an initial humidity of 33% RH. Exposure times were 5 hours, 1 day, 2 days, and 3 days. The same 12 mL plastic vial containing a mixture of 600 mg LPSC and 600 mg SH (weight ratio 1:1) was exposed to an open-environment test fume hood with a humidity of 40% RH for 10 minutes. After air exposure, the samples were placed in a vacuum oven and dried at 80°C for 2 hours with a heating gradient of 1°C / min to remove excess solvent and moisture from the material surface. Subsequently, the dried samples were transferred to a glove box for additional testing. Note that the 300°C heating step, which resulted in a crystal structure and conductivity consistent with untreated LPSC, could completely remove all SH residue (Figure 27). However, the 80°C drying step was sufficient to remove most of the SH without adversely affecting the conductivity and stability of Li.

[0140] To quantitatively evaluate the air stability of various LPSC samples under specific humidity conditions, a home-built system was used, as illustrated in Figure 15a. A humidifier was used to ensure a consistent initial humidity of 33% RH. Unless otherwise noted, 600 mg of LPSC, or a mixture of 600 mg of LPSC and 120 mg of SH, was placed in a 16 oz airtight container. A thermometer and hygrometer were placed near the sample to monitor changes in atmospheric humidity levels over time. Figure 16a shows the change in relative humidity (RH) inside the container as a function of exposure time (t). Because it is a closed environment, water consumption due to reaction with LPSC leads to a decrease in relative humidity. After 72 hours (3 days) of exposure, the relative humidity inside the LPSC container decreases from 33% to 7%. In contrast, the relative humidity inside the SH@LPSC container decreases from 33% to 13%. The water absorption rate of LPSC can be estimated by the first derivative of relative humidity with respect to time. The results shown in Figure 16b clearly demonstrate a significant reduction in moisture absorption by SH@LPSC, further confirming the effectiveness of the SH surface modifier in mitigating moisture reactivity. Prior to subsequent characterization of the air-exposed sample, a vacuum drying procedure was performed at 80°C for 2 hours.

[0141] The XRD pattern in Figure 15b shows that in the SH@LPSC sample, no new phases form after 1 day of exposure to 33%RH air, while after 3 days of exposure, new peaks begin to appear at 25° and 35° with very low intensity. This suggests that the basic structure of LPSC remains unchanged, and that SH plays an effective role as a protective agent. Conversely, the XRD pattern of LPSC after 3 days of exposure to 33%RH air shows the major Li2S and LiCl decomposition phases, indicated by the peaks at 25° and 35°. The complete XRD dataset is provided in Figure 17.

[0142] Raman spectroscopy was used to monitor the changes in the bulk LPSC structure when exposed to moist air. 3- The unit corresponds to 424.5 cm -1We monitored the change in the peak (Figure 15c), which is the core structural component responsible for the excellent ionic conductivity of sulfide SSE. As the material degrades, the peak shifts to lower wavenumbers, which may be due to the decomposition of PS bonds into PO bonds, forming oxythiophosphate species, but further investigation is needed for accurate speciation. The spectrum obtained from the SH@LPSC 1D air sample was 424.5 cm⁻¹. -1 While there is no change in the peak, the SH@LPSC 3D air sample is PS4 3- When the unit degrades by 16.2%, the shift of the same peak is very small. In contrast, the LPSC 1D air sample shows a considerable peak shift, and the PS4 3- This shows a 41.8% decrease in units. These results are consistent with XRD results indicating that, in the case of SH@LPSC SSE, the bulk structure begins to degrade approximately 3 days after exposure to moist air.

[0143] Figures 15d-e plot the ionic conductivity of electrolyte pellets manufactured by cold pressing. When SH absorbent is applied, the ionic conductivity of SH@LPSC is 1.8 ± 0.16 mS cm, based on the average of three independent measurements, as shown in Figures 15d-e. -1 From 1.6 ± 0.03 mS cm -1 It decreases slightly. This slight decrease may be due to the introduction of components with low ionic conductivity into the system. SH@LPSC shows excellent stability after 5 hours, 1 day, and 2 days of exposure to air, which is due to the change in ionic conductivity over time being 1.1 mS cm. -1 From 1.0 mS cm -1 This is based on very small values ​​(Figure 15e). On the other hand, LPSCs without SH coating had an ionic conductivity of 0.15 mS cm after 5 hours of exposure to air. -1The ionic conductivity of LPSC during exposure decreases significantly (Figure 3e). The change in ionic conductivity of LPSC during exposure is a function of both humidity and time. As the amount of LPSC in the closed container decreases from 600 mg (Figure 15e) to 200 mg (Figure 18) and the H2O to LPSC ratio increases, the relative effectiveness of SH protection becomes much more pronounced. SH@LPSC has an ionic conductivity of 0.4 mS cm after 1 day of exposure to air. -1 So, LPSC (0.003 mS cm) -1 ) is two orders of magnitude higher. The experiment was conducted by exposing LPSC and SH@LPSC (weight ratio LPSC:SH = 1:1) to air in a 40% RH chemical fume hood. Due to the combined effect of the complex airflow pattern of the fume hood and the potential for SH to disappear, the experimental conditions could not be controlled to the same extent as the closed system used in the rest of this study, which would allow for easier quantification of the sample transitions. Nevertheless, SH@LPSC and LPSC were 0.5 mS cm, respectively. -1 and 0.003 mS cm -1 When the conductivity is shown, a two-order-of-magnitude improvement in ionic conductivity retention is again observed (Figure 15d). To illustrate the results in context, Figures 15f-g summarize previously reported stability data collected from modified LPSC electrolytes after air / moisture exposure. SH protection extends LPSC protection time from minutes to days (Figure 15f). Conductivity loss is generally ~100 times lower (Figure 15g). This approach enables sulfide SSE treatment under standard atmospheric conditions without additional humidity control, dramatically reducing manufacturing costs. Furthermore, sufficient stability can be expected in a standard dry room with a dew point of -40°C.

[0144] (12) Surface protection mechanism After exposure to air (33% RH), the material changes were monitored using XPS and solid-state NMR (ssNMR), and the results are shown in Figure 19. Examination of LPSC 1D air and LPSC 3D air samples revealed SO4 at 167 eV. x 2-The SO peak originating from the oxysulfide (POxSy) appears (Figure 19a), and at 132.5 eV, the intensity of the PO peak originating from the oxysulfide (POxSy) increases (Figure 19b), indicating that hydrolysis occurs, and S 2- Oxidation is evident. Conversely, in the SH@LPSC 1D air and SH@LPSC 3D air samples (Figure 19a), no SO peaks appeared, and the intensity of the PO peak was unchanged compared to SH@LPSC (Figure 10d) (Figure 19b). The SS bond strength of SH@LPSC 1D and SH@LPSC 3D is almost the same as that of SH@LPSC. The bond between SH and LPSC protects the surface from oxidation, while hydrolysis reactions are significantly reduced, allowing important PS 3 units to be effectively preserved.

[0145] Also, before and after exposing the LPSC and SH@LPSC samples to moist ambient air, 31 The P and 6Li ssNMR spectra were used for investigation, and the results are shown in Figures 19c and 20, respectively. Because ssNMR is element-specific and sensitive to both crystalline and amorphous phases, the LPSC electrolyte... 31 P and 6 Li nuclei can be selectively probed. Obtained from LPSC and SH@LPSC samples. 31 No significant differences were observed between the P spectra, which means that the LPSC bulk structure does not change when mixed with SH. (Collected from SH@LPSC 1D air samples) 31 The P ssNMR spectrum is almost identical to that obtained from the LPSC, indicating that the coating protects the LPSC structure from degradation. Even after 3 days in air, the SH@LPSC sample showed no degradation due to the untreated LPSC. 31 Most of the P-spectral features are preserved. Nevertheless, new resonances appear at 82.9 and 88.7 ppm, as well as β-Li3PS 4 PS4 isolated in a similar environment 3-The appearance of a third resonance at 86.8 ppm, which is assigned to the tetrahedron, indicates the beginning of degradation. When exposed to air without any protection, the LPSC bulk structure degrades significantly, resulting in the disappearance of the broad resonance of untreated LPSC and the emergence of sharp resonances at 82.9 and 88.7 ppm, respectively (POS3). 3- PS4 isolated in a tetrahedral unit and Li3PS4-like environment. 3- This is reflected by being assigned to and appearing in a tetrahedron. Interestingly, air exposure in the SH@LPSC sample is reflected in the isolated PS4 3- More Li3PS like tetrahedrons 4- This is believed to form, and this is evidenced by the higher resonance intensities at 86.8 ppm and 88.7 ppm in the spectra collected from the SH@LPSC 3D air sample compared to the spectra obtained from the LPSC 3D air sample. Overall, 31 P and 6 Li ssNMR results clearly demonstrate that SH modification delays the onset of degradation and preserves the LPSC structure almost completely even after exposure to ambient air for up to 3 days. Finally, collected from SH@LPSC and SH@LPSC 1D air samples... 1 The H spectrum (Figure 21), as can be seen from the decrease in the broad peak (~3.5 ppm) near (a), suggests that the amount of SH adsorbed on the LPSC surface decreases with air exposure time (presumably due to evaporation), which can partially explain the decrease in the efficiency of the SH coating as the exposure time increases.

[0146] Even in a series of samples modified with CH instead of SH, before and after exposure to 33%RH air for one or two days... 6 Li and 31P spectra were collected. These samples are shown as CH@LPSC, CH@LPSC 1D air, and CH@LPSC 3D air. The results shown in Figures 22-23 highlight the important role of the thiol chain end of SH in the protection mechanism of LPSC. When CH (with methyl instead of the thiol terminal group) is coated, the LPSC SSE cannot be protected from hydrolysis, and the CH@LPSC 1D air sample... 6 Li and 31 Significant changes are observed in P resonance.

[0147] Because SH's air stability and ability to form SS bonds with the LPSC surface have been confirmed, SH is a powerful hydrophobic protective agent. Specifically, SH forms a strong impermeable layer, preventing water from reaching the LPSC surface. This protective film prevents LPSC from reacting with ambient moisture for up to several days. Slow SH@LPSC degradation during prolonged air exposure may be related to water penetration through defects that bypass the SH protective layer or through SH evaporation that exposes the unbonded LPSC surface.

[0148] (13) Improved electrochemical performance LPSCs and SH@LPSC SSEs were exposed to air for one day, and their electrochemical stability in Li symmetric and full cells was studied. Li / Li symmetric cells are commonly used to evaluate the interfacial stability between SSEs and lithium metal. Critical current density (CCD) is an indicator of how well the SSE can withstand short circuits caused by lithium dendrite growth. Figure 24 shows a CCD value of 0.6 mA cm² for SH@LPSC 1D air at room temperature. -2 While there was no change compared to the untreated LPSC, the CCD value of the LPSC 1D air was 0.63 mA cm⁻¹. -2 From 0.3mA cm -2 This indicates a decrease. Therefore, in SH@LPSC 1D air, surface modification due to air exposure does not appear to change the interaction between LPSC and Li. Also, Figure 25 shows 1.5 mAh cm -2 Li in capacitive loading 0.5In / Li Mon 0.8 Co 0.1 Mn 0.1 This shows the constant current cycling performance of O2. Compared to a baseline cell using untreated LPSC electrolyte (Figure 26), cells fabricated with LPSC after 1 day of air exposure (Figure 25(a~b)) showed increased electrolyte resistance and a decrease in cell voltage of approximately 80mV after the formation cycle, as well as a decrease in discharge capacity of 135mAh g. -1 And even lower. On the other hand, after one day of exposure to air, cells fabricated with SH@LPSC (Figure 25(c~d)) showed similar levels of 155mAh g as the untreated LPSC full cell (Figure 26). -1 It exhibits a capacity retention rate of 80% even after 50 cycles. This observation provides strong evidence for the remarkable protective effect that SH has on LPSCs, particularly in mitigating the adverse effects of moisture exposure.

[0149] These experiments demonstrate that the long-chain thiol 1-undecanethiol can be used to effectively protect the Li6PS5Cl solid electrolyte from exposure to humid air. It was found that 1-undecanethiol is chemically compatible with Li6PS5Cl, has minimal effect on conductivity, and can be almost completely removed by a vacuum drying process. Structural analysis showed that the -SH terminal group does not disrupt the PS network structure essential for ionic conductivity and forms SS bonds with S atoms on the surface of the solid electrolyte. The hydrocarbon tail of the thiol forms a hydrophobic layer that effectively repels water. The novel SH surface modification proved effective in maintaining the bulk structure and ionic conductivity of Li6PS5Cl even during prolonged exposure to humid air. The SH-modified solid electrolyte maintained >1 mS cm for 2 days when exposed to air at 33% relative humidity. -1The ionic conductivity is maintained. Such excellent results represent a significant advance in terms of moisture protection time, exceeding previous research in this field by two orders of magnitude. With 1-undecanethiol protection, the electrolyte exhibits similar performance to that of an all-solid-state battery even after 1 day of exposure to air. This result demonstrates the potential of 1-undecanethiol surface modification for storing highly air-sensitive sulfide solid electrolytes outside of glove boxes or in dry rooms, paving the way for more practical, efficient, and scalable methods for manufacturing sulfide solid batteries.

[0150] Material property specification Raman spectroscopy (Renishaw TM inVia TM The measurement was performed at an excitation wavelength of 785 nm, with a range of 300-2500 cm⁻¹. -1 The experiment was conducted within the specified range. All powders were prepared by hand-grinding them in a glove box covered with Kapton tape to prevent air exposure during measurement. Liquid SH samples were taken before and after air exposure. 1 Analysis was performed by 1H NMR spectroscopy. To prepare the samples, 100 μl of SH or air-exposed SH specimens were mixed with 1000 μl of chloroform D (99%, sigma-Aldrich), and then transferred to NMR sample tubes. 1 ¹H NMR was performed using a 500 MHz spectrometer (ECA500, JEOL). Powder XRD (D8 DISCOVERY, Bruker) was measured at 10°–80° with a scan rate of 2° / min. Samples were sealed using Kapton tape. For cryo-TEM imaging, specimens were placed on a copper grid and fixed in a dual-tilt cryo-TEM transfer holder in a liquid nitrogen environment. Cryo-TEM images were captured using a JEM-2100F electron microscope operating at a 200 kV acceleration voltage. XPS analysis was performed using a Kratos Analytical AXIS Supra XPS instrument. XPS data were collected in 10 -8XPS spectra were acquired using a monochromatic Al Kα source emitted at 1,486.7 eV along with the sample in an ultra-high vacuum environment at Torr. Samples were transferred from a nitrogen-filled glove box to avoid further air exposure. Prior to analysis, a 10 keV Ar (1000 atoms) cluster source was applied for 60 seconds for surface cleaning. All XPS spectra were corrected for the exogenous C 1s peak at 284.6 eV and then analyzed using CasaXPS software. For solid-state NMR, all spectra were acquired at 18.8 T (800 MHz for 1 H) on a Bruker Ultrashield Plus standard bore magnet fitted with an Avance III console. 1 H and 31 P solid-state NMR spectra were obtained under Ar under a 60 kHz spinning speed using a 1.3 mm HX MAS probe with a zirconia rotor sealed with a Vespel cap. N2 gas flow (2000 l / hr) was used to control rotor temperature and protect the sample from moisture contamination. Data were obtained using a rotor-synchronized spin-echo pulse sequence (90°-TR-180°-TR-477 ACQ). 1 For H, the flip angles of 90° and 180° at 75W were set to 1.6μs and 3.2μs, respectively. 31 For P, flip angles of 90° and 180° at 75W were used for 1.5 μs and 3.0 μs, respectively. 1 The H solution state spectrum was obtained using a BBO 800 MHz S4 5 mm probe. Data were obtained using a single-pulse sequence with direct excitation at 21 W and a 30° flip angle for 4.8 μs. The 1H chemical shift was measured using adamantane at 0.247 ppm of tetrakis(trimethylsilyl)silane. 1 The H signal was referenced indirectly. 31 The P chemical shift is at 0 ppm of 85% H3PO4. 31 I referred to the P signal. 6Li solid-state NMR spectra were obtained using a 3.2 mm HXY MAS probe with a zirconia rotor sealed under Ar with a Vespel cap, at a spinning speed of 20 kHz. For rotor-synchronized spin-echo pulse sequences, flip angles of 90° and 180° were used at 200 W for 8.0 μs and 16.0 μs, respectively. 6 Li chemical shift was referenced to 0 ppm 1 M LiCl. SH@LPSC sample. 1 Spectra for H quantification were obtained using a 2.5 mm HX MAS probe with a zirconia rotor sealed with a Vespel cap under Ar, at a rotation speed of 20 kHz. Sample content and for quantification 1 To maximize the H signal, a larger rotor size was used. For the rotor-synchronous spin-echo pulse sequence, flip angles of 90° and 180° were used at 100W for 2.66μs and 5.32μs, respectively. T2* measurements were performed for each sample to compensate for non-uniform signal attenuation during the 50μs echo delay. For each sample, a series of rotor-synchronous spin-echoes with variable echo delays (90°-TR-180°-TR-ACQ) were obtained, and the spectra were fitted using an in-house package to obtain accurate T2* values. 1 To ensure the quantification of H, spectra and T2* measurements were obtained even with an empty rotor. The same measurements were then repeated for adamantane of known mass, subtracting the signal contribution from the empty rotor. 1 The H content was corrected to the integrated spectral intensity. The same measurements were performed on an untreated LPSC sample and two SH@LPSC samples dried at 80°C and 300°C, respectively. For each sample, the proton content was calculated considering the T2* signal decay of each fitted component and the contribution of the empty rotor. For the dried SH@LPSC samples, the 1-undecanethiol content of the sample was calculated by subtracting the proton content of the untreated LPSC.

[0151] Battery assembly To evaluate the electrochemical performance, an ASSB Swagelok cell consisting of a polyaryl ether ether ketone (PEEK) mold and Ti rods was assembled. In the symmetric cell, 200 mg of solid electrolyte powder was compressed into a 13 mm diameter pellet under a pressure of 375 MPa. A lithium metal foil with a diameter of 1.11 cm and a thickness of 100 μm was attached to both sides of the electrolyte pellet. Subsequently, the resulting Li / SSE / Li symmetric cell was sandwiched between two Ti rods. In the full cell, NCM811(LiNi) was prepared using a mortar and pestle. 0.8 Co 0.1 Mn 0.1 A cathode composite was fabricated by mixing O2 (LG Energy Solutions), LPSC (Ampcera Inc., used as received), and vapor-grown carbon fiber (Sigma-Aldrich) in a weight ratio of 60:37:3. 100 mg of untreated LPSC and 100 mg of air-exposed SSE (sample in Figure 15f) were compressed at 30 MPa to form a bilayer electrolyte pellet. Subsequently, 16.2 mg of the cathode composite was introduced into the untreated LPSC side and pressed at 375 MPa. A Li-ion ion with a diameter of 1.11 cm was used. 0.5 The In alloy was attached to the air-exposed SSE side and pressed at 125 MPa. Subsequently, the obtained Li 0.5 An In / air-exposed SSE / LPSC / cathode cell was sandwiched between two Ti rods. During testing, the symmetrical cell and the full cell were maintained at 30 MPa and 55 MPa, respectively. All cells were assembled in a glove box under an argon atmosphere.

[0152] Electrochemistry Test Cell measurements were performed using a LAND multi-channel battery test system. Constant current charge-discharge tests of symmetrical cells were performed at room temperature with gradually increasing current density for 0.5 hours per half-cycle. Constant current charge-discharge tests of full cells were performed at 60°C at a rate of 0.1C within a voltage range of 1.9–3.65V. Impedance measurements were performed at room temperature using a frequency response analyzer (CH Instruments workstation) with an amplitude of 5mV in the frequency range of 7MHz–100MHz. For the impedance measurement setup, a 100mg electrolyte with a diameter of 13mm and maintained at 375MPa was used at room temperature, while a Ti rod served as the blocking electrode.

[0153] Those skilled in the art will understand that aspects of this disclosure do not affect the scope of the disclosures described herein and can be implemented within a broad range of equivalent parameters. All publications, patent applications and patents disclosed herein are incorporated by reference in their entirety.

Claims

1. A sulfide-containing solid electrolyte material having a surface; and Organic coating formed on the surface of the sulfide-containing solid electrolyte material A solid electrolyte composition containing, A solid electrolyte composition in which the organic coating is formed of at least one of the compounds of chemical formulas 1 and 2 below: [Chemical formula 1] R-A [Chemical formula 2] R-A'-R In the above formula, A is an SH group, isocyanate, amine, or leaving group; A' is the -S- part or the -S-S- part; Each R is independently a substituted or unsubstituted C3-C20 alkyl group.

2. The solid electrolyte composition according to claim 1, wherein the compound of chemical formula 1 or chemical formula 2 is attached to the surface of the sulfide-containing solid electrolyte material by chemiadsorption, van der Waals interaction, or ionic interaction.

3. The solid electrolyte composition according to claim 1, wherein the compound of chemical formula 1 or chemical formula 2 reacts with the sulfide-containing solid electrolyte material to form a covalent bond.

4. The solid electrolyte composition according to claim 1, wherein in the compound of chemical formula 1, A is an SH group.

5. The solid electrolyte composition according to claim 1, wherein in the compound of chemical formula 1, A is one or more leaving groups selected from triethoxysilyl and trimethoxysilyl.

6. The solid electrolyte composition according to claim 1, wherein in the compound of chemical formula 1 or chemical formula 2, at least one of R is a C6-C16 alkyl group.

7. The solid electrolyte composition according to claim 1, wherein in the compound of chemical formula 1 or chemical formula 2, at least one of R is a C8-C12 alkyl group.

8. The solid electrolyte composition according to claim 1, wherein the total number of carbon atoms in the compound of chemical formula 1 or chemical formula 2 is 6 to 16.

9. The solid electrolyte composition according to claim 1, wherein the total number of carbon atoms in the compound of chemical formula 1 or chemical formula 2 is 8 to 12.

10. The solid electrolyte composition according to claim 1, wherein in the compound of chemical formula 1 or chemical formula 2, at least one of R is a C3-C20 alkyl group, and the C3-C20 alkyl group has one or more substituents selected from the group consisting of fluorine, chlorine, bromine, ester, and ketone moieties.

11. The solid electrolyte composition according to claim 1, wherein the compound of chemical formula 1 is 1-undecanethiol.

12. The solid electrolyte composition according to any one of claims 1 to 11, wherein the sulfide-containing solid electrolyte material is selected from the group consisting of inorganic electrolyte materials and organic electrolyte materials.

13. The solid electrolyte composition according to any one of claims 1 to 11, wherein the sulfide-containing solid electrolyte material is an inorganic electrolyte.

14. The sulfide-containing solid electrolyte material is Li ３ P ７ S １１ , Li １０ GeP ２ S １２ , Na ３ PS ４ , and Li ６ PS ５ The solid electrolyte composition according to any one of claims 1 to 11, comprising at least one selected from Cl.

15. The sulfide-containing solid electrolyte material is given by formula xLi ２ S-yP ２ S ５ A solid electrolyte composition according to any one of claims 1 to 11, comprising at least one selected from the group consisting of LPS-based glass and glass ceramics (where x + y = 1).

16. The sulfide-containing solid electrolyte material is of the formula Li ６ PS ５ A solid electrolyte composition according to any one of claims 1 to 11, comprising an argyrodite-based solid electrolyte of X (where X is Cl, Br, or I).

17. The sulfide-containing solid electrolyte material is of the formula Li ６－ｙ PS ５－ｙ Cl １＋ｙ A solid electrolyte composition according to any one of claims 1 to 11, comprising an argyrodite-based solid electrolyte (where y < 1).

18. We provide a sulfide-containing solid electrolyte material. The sulfide-containing solid electrolyte material is combined with at least one of the compounds of chemical formulas 1 and 2 below to form a coated sulfide-containing solid electrolyte material. Using the coated sulfide-containing solid electrolyte material, a solid electrolyte is formed. A method for producing a solid electrolyte composition according to claim 1, including: [Chemical formula 1] R-A [Chemical formula 2] R-A'-R In the above formula, A is an SH group, isocyanate, amine, or leaving group; A' is the -S- part or the -S-S- part; Each R is independently a substituted or unsubstituted C3-C20 alkyl group.

19. We provide a sulfide-containing solid electrolyte. The sulfide-containing solid electrolyte is combined with at least one of the compounds shown in Chemical Formula 1 and Chemical Formula 2 below to form a coated sulfide-containing solid electrolyte material. A method for producing a solid electrolyte, including: [Chemical formula 1] R-A [Chemical formula 2] R-A'-R In the above formula, A is an SH group, isocyanate, amine, or leaving group; A' is -S-; Each R is independently a substituted or unsubstituted C3-C20 alkyl group.

20. A solid electrolyte comprising the solid electrolyte composition according to claim 1.

21. Negative electrode; Positive electrode; and A solid electrolyte according to claim 20, interposed between the negative electrode and the positive electrode. All-solid-state batteries, including those mentioned above.

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