Solid electrolyte material and solid battery manufactured using the same

Abstract

A solid electrolyte material comprising Li, T, X, and A, where T is at least one of P, As, Si, Ge, Al, and B, X is BH4, and A is S, Se, or N. The solid electrolyte material may comprise a glass-ceramic and / or mixed crystalline phase, and may exhibit high ionic conductivity and compatibility with high voltage cathodes and lithium metal anodes.

Description

[Technical Field]

[0001] Cross-reference with related applications This application claims priority to U.S. Provisional Application No. 62 / 993,571, filed on 23 March 2020, and U.S. Provisional Application No. 63 / 088,233, filed on 6 October 2020, and the entire contents of both applications are incorporated herein by reference.

[0002] Technical field The various embodiments described herein relate to the field of solid primary and secondary electrochemical cells, electrodes and electrode materials, electrolytes and electrolyte compositions, and corresponding methods for manufacturing and using them. [Background technology]

[0003] The increasing number and diversity of mobile devices, the evolution of hybrid / electric vehicles, and the development of Internet of Things devices are creating a greater need for battery technologies with improved reliability, capacity (Ah), thermal properties, lifespan, and recharge performance. Currently, lithium solid-state battery technology offers potential improvements in safety and packaging efficiency, and enables novel high-energy chemistry, but further improvements are needed. Specifically, efforts are being made to improve the manufacturing and performance characteristics of solid electrolyte compositions.

[0004] The most widely studied and adopted inorganic solid ion conductors are the so-called "lithium argyrodites." These materials originate from argyrodites, a natural mineral with the composition Ag8GeS6, which was first reported in 1886 (Winkler, C. (1886) Germanium GE, ein nues, nichtmetallisches Element. Ber. Dtsch. Chem. Ges. 19: 201-211). Generalizing the composition of such materials, U.S. Patent No. 8,075,865 states the formula Li + (12-n-y) T n+ A 2-(6-y) X - (y) gives, and this formula defines "lithium argyrodite" which has mobile lithium ions and is useful as a solid electrolyte. Typically, lithium argyrodite has a cubic crystal structure of space group F-43m, while natural mineral argyrodite has an orthorhombic crystal structure of space group Pna21. Generally, the terms "argyrodite-type" or "argyrodite-like" refer to crystalline substances that satisfy the above formula rather than a specific crystal structure.

[0005] The lithium ion conductivity of argyrodite-type materials has been demonstrated to correlate with the amount of the component "X" in the formula Li + (12-n-y) T n+ A 2- (6-y) X - (y) Considering the general composition of "lithium argyrodite" where "T" = P, "A" = S, and "X" = Cl, Adeli et al. (Adeli, P.; Bazak, J.D.; Park, K.H.; Kochetkov, I.; Huq, A.; Goward, G.R.; Nazar, L.F.) in Agnew.Chem. Int. Ed. (2019) 58, 8681) have demonstrated that the conductivity increases until y = 1.5 and it is impossible to incorporate Cl into the structure beyond y = 1.5. For typical halogen species such as Cl, Br, and I, it is impossible to further increase the halogen component. The present disclosure overcomes this limitation by adopting the use of pseudohalogen species such as BH4, BF4, etc., enabling the limit of the component "X" to be raised to a new limit of y = 2 in the argyrodite-type phase, thereby significantly improving the conductivity.

[0006] Incorporating pseudohalogen species such as BH4 and BF4 is even more desirable because they have higher oxidation potentials compared to halogen species such as Cl and Br. This is because a higher oxidation potential can improve the electrochemical stability of high-voltage active materials. For example, U.S. Patent No. 10,411,295 describes incorporating the pseudohalogen species BH4 into the zLiBH4·(1-z)P2S5 system and its use as a solid electrolyte. However, the conductivity of this material is limited to <2 mS / cm due to limitations in its crystal structure. Considering the limited availability of the component Li in this system, the formula Li described in U.S. Patent No. 8,075,865 is preferable. + (12-n-y) T n+ A 2- (6-y) X - (y) This condition cannot be satisfied. This means that the formation of an argyrodite-type phase is not favorable. Furthermore, all argyrodite-type materials containing "T"=P and "A"=S are known to contain the structural unit PS4 as the sole phosphorus-containing building block, as can be demonstrated, for example, by the use of Raman spectroscopy. The Raman spectrum reported in U.S. Patent No. 10,411,295 demonstrates that the structure of this material is not argyrodite-type due to the presence of alternative PS bonds. In contrast, the present disclosure provides an argyrodite-type material incorporating the pseudohalogen species BH4, which is the first BH4-containing sulfide solid electrolyte to demonstrate high conductivity >> 2 mS / cm. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Sakuda et al. (Sakuda, A.; Yamauchi, A.; Yubuchi, S.; Kitamura, N.; Idemoto, Y.; Hayashi, A.; Tatsumisago, M. ACS Omega (2018) 3(5), 5453-5458; hereinafter, "Sakuda") have published a patent application for Li in U.S. Patent No. 8,075,865. + (12-n-y)T n+ A 2- (6-y) X - (y) describes a material called an aldirodite-type material, in which the formula described by ""T"" = P, ""A"" = S, ""X"" = BH4, and y = 1. The present disclosure differs from Sakuda's in two important respects. First, the distinct difference in X-ray diffraction indicates the difference in crystal structure between Sakuda's and that disclosed in the present disclosure. In Sakuda's case, the peaks in the range of 25 - 35 degrees show higher relative intensities, which indicates the first structural difference, and the diffraction peak at 14.6 degrees is absent, which indicates the second structural difference between Sakuda's and that disclosed in the present disclosure. Second, Sakuda teaches a crystalline fraction including those in which y = 1 in Li + (12-n-y) T n+ A 2- (6-y) X - (y) and teaches that y > 1 is not possible, whereas in the present disclosure, y is greater than 1 (1 < y ≤ 2). These structural and compositional features are such that for Sakuda's material, the reported conductivity is a mediocre 1.8 mS / cm compared to the material of the present disclosure where 1 < y ≤ 2 and the measured conductivity is up to 8.9 mS / cm. Means for Solving the Problems

[0008] In one embodiment, the aldirodite-type solid electrolyte material contains Li, T, X, and A, where T is at least one of P, As, Si, Ge, Al, and B, X is BH4, and A is S, Se, or N. This solid electrolyte material may contain a glass-ceramic phase and / or a mixed crystal phase and exhibits high ionic conductivity and compatibility with a high-voltage cathode and a lithium metal anode.

[0009] In another embodiment, the argyrodite-type solid electrolyte material comprises Li, T, X, and A, where T is at least one element selected from the group consisting of P, As, Si, Ge, Al, and B; X is one or more halogens or BH4, BF4, NH2, or NO3 or a combination thereof; and A is one or more of S, Se, and N. The solid electrolyte material has peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurements using Cu-Kα(1,2) = 1.5418 Å.

[0010] In yet another embodiment, the solid electrolyte material further comprises at least one of a glass ceramic phase, a crystalline phase, and a mixed phase.

[0011] In another embodiment, the solid electrolyte material has a ratio of the intensity of the peak at 2θ = 15.3° ± 0.25° to the intensity of the peak at 2θ = 14.6° ± 0.25° of 5:1 or less.

[0012] In another embodiment, the solid electrolyte material comprises Li, T, X, and A, where X consists of one or more halogens or a combination of BH4, BF4, NH2, or NO3.

[0013] In another embodiment, the solid electrolyte material comprises the formula LPS·zLiX, where LPS represents a mixture of Li2S and P2S5 in a glass-forming ratio, or a mixture of Li2S and B2S3 in a glass-forming ratio, and LiX represents LiCl, LiBr, LiI, LiBH4, LiBF4, LiNH2, and LiNO3, with 0.25 ≤ z ≤ 4.

[0014] In another embodiment, the solid electrolyte material comprises the formula LPSX·zLiX, where LPSX comprises a mixture of Li2S, P2S5, and LiX in a glass-forming ratio, or a mixture of Li2S, B2S3, and LiX in a glass-forming ratio, where LiX comprises one or more of LiCl, LiBr, LiI, LiBH4, LibF4, LiNH2, and LiNO3. <z≦25である。

[0015] In another embodiment, the solid electrolyte material comprises Li, T, X, and A, where X comprises BH4, and the presence of a peak at 2θ = 14.6° ± 0.25 in X-ray diffraction measurements using Cu-Kα(1,2) = 1.5418 Å is controlled by adjusting specific synthesis conditions without changing the nominal stoichiometry.

[0016] In another embodiment, the solid electrolyte material is Li + (12-n-y) T n+ A 2- (6-y) X - (y) This includes the condition y > 1.

[0017] In another embodiment, the solid electrolyte material is Li + (12-n-y) T n+ A 2- (6-y) X - (y) This includes the following, where T=P, A=S, X=BH4, and y>1.

[0018] In another embodiment, the solid electrolyte material comprises a mixture of a crystalline phase having peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurements using Cu-Kα(1,2)=1.5418Å, and one or more of LiBH4, LiBF4, LiNH2, LiNO3, LiSCN, and LiOCN.

[0019] In another embodiment, the solid electrolyte material includes a crystalline argyrodite-type phase that constitutes 50 mol% or more of the total phase present.

[0020] In another embodiment, the solid electrolyte material exhibits a main peak of 423±10 cm² in Raman spectroscopy measurements using 532 nm excitation. -1 It is located at an intensity ratio of at least 2:1, with other peaks ranging from 250 to 700 cm. -1 It exists within the range.

[0021] In another embodiment, the solid electrolyte material is 2 The ratio of the peak intensity at 2θ=15.3° to the peak intensity at θ=17.5° is 1 or greater.

[0022] In another embodiment, the lithium battery includes (a) a positive electrode active material layer containing a positive electrode active material, (b) a negative electrode active material layer containing a negative electrode active material, and (c) a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, wherein at least one of the positive electrode active material layer, the negative electrode active material layer and the solid electrolyte layer contains a sulfide solid electrolyte material comprising an algyrodite-type solid electrolyte material containing Li, T, X, and A, where T is P, As, Si, Ge, Al The solid electrolyte material is at least one element selected from the group consisting of and B, where X is one or more halogens or BH4, BF4, NH2, or NO3 or a combination thereof, and A is one or more of S, Se, and N. In X-ray diffraction measurements using Cu-Kα(1,2)=1.5418Å, the solid electrolyte material has peaks at 2θ=14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25°.

[0023] In another embodiment, a method for producing a solid electrolyte material comprises mixing and milling a raw material composition containing element A or compound Li2A or Li3N, element T or a sulfide of T, and compound LiX until the precursor material is substantially amorphous or alloyed to produce a final sulfide glass composition, and optionally heating the sulfide glass at a heat treatment temperature above the crystallization temperature of the material to synthesize a glass ceramic having peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° by X-ray diffraction measurement with Cu-Kα(1,2) = 1.5418 Å, wherein the solid electrolyte material comprises a glass ceramic containing Li, T, X, and A, where T is at least one of P, As, Si, Ge, Al, and B, X is a halogen and / or BH4, BF4, NH2, or NO3, and A is at least one of S, Se, and N.

[0024] In another embodiment, the method for producing a solid electrolyte material is: 2This yields a final composition in which the ratio of the peak intensity at 2θ=15.3° to the peak intensity at θ=17.5° is 1 or greater.

[0025] In another embodiment, a method for producing a solid electrolyte material comprises mixing a suitable precursor containing components Li, T, X, and A in a solvent capable of causing a reaction between the precursors, removing the solvent, and optionally heat-treating the material at a temperature above the crystallization temperature, wherein the solid electrolyte material comprises a glass ceramic containing Li, T, X, and A, where T is at least one of P, As, Si, Ge, Al, and B, X is a halogen and / or BH4, BF4, NH2, or NO3, and A is at least one of S, Se, and N.

[0026] This disclosure will be understood by referring to the following detailed description in conjunction with the drawings briefly described below. Note that for illustrative clarity, certain elements in the drawings may not be drawn to scale. [Brief explanation of the drawing]

[0027]

Figure 1

[0028]

Figure 2

[0029]

Figure 3a

Figure 3b

Figure 3c

[0030]

Figure 4a

Figure 4b

[0031]

Figure 5

[0032]

Figure 6a

Figure 6b

Figure 6c

[0033] The following description provides specific details to give a thorough understanding of the various embodiments of this disclosure. However, by reading and understanding the specification, claims and drawings of this application, those skilled in the art will understand that some embodiments of this disclosure may be carried out without following some of the specific details described herein. Furthermore, to avoid obscuring this disclosure, some well-known methods, processes, devices, and systems that are expected to be applied to the various embodiments described herein are not disclosed in detail.

[0034] definition In this specification, the acronym "LPS" is used to represent an electrolyte phase composed of Li2S:P2S5 in a defined ratio. If not defined, a ratio of 3Li2S:P2S5 may be assumed, which is known to result in the electrolyte phase Li3PS4. The term "semicrystalline" may mean partially crystalline, having crystalline domains small enough to cause peak broadening in X-ray diffraction, possessing both glassy and crystalline properties, containing crystalline and glassy phases which may have different compositions, or any combination thereof. The term "crystalline phase" may be understood to mean a material consisting of a fully crystalline or "semicrystalline" atomic order. "Mechanochemical synthesis" may refer to a synthesis technique that uses mixing or grinding energy of a medium with a precursor material to cause mixing and / or reaction of such material. "Argyrodite-like" and "argyrodite-type" refer to "lithium argyrodite," Li + (12-n-y) T n+ A 2- (6-y) X - (y) It may be used interchangeably to represent materials that conform to the chemical relationships defined in U.S. Patent No. 8,075,865, which describes them.

[0035] Figure 1 is a schematic cross-sectional view showing an exemplary structure of a lithium solid electrochemical cell containing the electrode composition of this disclosure. The lithium solid battery 100 includes a positive electrode (current collector) 110, a positive electrode active material layer (cathode) 120, a solid electrolyte layer 130, a negative electrode active material layer (anode) 140, and a negative electrode (current collector) 150. The solid electrolyte layer 130 may be formed between the positive electrode active material layer 120 and the negative electrode active material layer 140. The positive electrode 110 is in electrical contact with the positive electrode active material layer 120, and the negative electrode 150 is in electrical contact with the negative electrode active material layer 140. The solid electrolyte composition as described in this disclosure may form part of the positive electrode active material layer 120, the negative electrode active material layer 140, and the solid electrolyte layer 130.

[0036] The positive electrode 110 can be formed from materials such as aluminum, nickel, titanium, stainless steel, or carbon, but is not limited to these materials. Similarly, the negative electrode 150 can be formed from copper, nickel, stainless steel, or carbon. The negative electrode 150 may be completely omitted if the negative electrode active material 140 has sufficient electronic conductivity and mechanical strength. The positive electrode active material layer 120 may contain at least a positive electrode active material such as (but not limited to) a metal oxide, metal phosphate, metal sulfide, sulfur, lithium sulfide, oxygen, or air, and may further contain a conductive material and / or binder, such as a solid electrolyte material, for example, a solid electrolyte composition as described herein. Examples of conductive materials include, but are not limited to, carbon (carbon black, graphite, carbon nanotubes, carbon fiber, graphene), metal particles, filaments, or other structures. Examples of binders include, but are not limited to, polyvinyl chloride (PVC), polyaniline, poly(methyl methacrylate) ("PMMA"), nitrile butadiene rubber ("NBR"), styrene butadiene rubber (SBR), PVDF, or polystyrene. The positive electrode active material layer 120 may contain, for example, 5% to 80% by volume of the solid electrolyte composition as described herein. The thickness of the positive electrode active material layer 120 can be, for example, in the range of 1 μm to 1000 μm.

[0037] The negative electrode active material layer 140 may contain at least a negative electrode active material such as lithium metal, lithium alloy, Si, Sn, graphite carbon, hard carbon, etc. (but not limited to these), and may further contain a conductive material and / or binder, such as a solid electrolyte material, for example, a solid electrolyte composition as described in this disclosure. An example of a conductive material is the material used in the positive electrode material layer. An example of a binder is the material used in the positive electrode material layer. The negative electrode active material layer 140 may contain the solid electrolyte composition as described in this disclosure, for example, in an amount of 5% to 80% by volume. The thickness of the negative electrode active material layer 140 can be, for example, in the range of 1 μm to 1000 μm.

[0038] The solid electrolyte material contained in the solid electrolyte layer 130 is one or more of the solid electrolyte compositions described in this disclosure. The solid electrolyte layer 130 may contain, for example, the solid electrolyte compositions described in this disclosure in an amount ranging from 10% to 100% by volume. Furthermore, the solid electrolyte layer 130 may contain a binder or other modifier. Examples of binders include additional self-healing polymers and poly(ethylene) oxide (PEO) in addition to the materials used in the cathode material layer. The thickness of the solid electrolyte layer 130 is in the range of 1 m to 1000 m.

[0039] Although Figure 1 shows a lamellar structure, it is well known that other shapes and configurations of solid-state electrochemical cells are possible. Most commonly, lithium solid-state batteries can be manufactured by sequentially stacking a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer, pressing them between the electrodes, and then providing a housing.

[0040] Figure 2 is a flowchart of a process for producing a solid electrolyte composition useful for constructing a secondary electrochemical cell. Process 200 begins with preparation step 210, which may involve optional preparatory operations such as precursor synthesis, purification, and apparatus preparation. Following any initial preparation, process 200 proceeds to step 220, in which sulfur compounds, lithium compounds, and other compounds as described herein may be combined with a suitable solvent and / or other liquid. Exemplary sulfur compounds include, for example, elemental sulfur, phosphorus pentasulfide (P2S5), and lithium sulfide (Li2S), typically in powder form. Exemplary lithium compounds include, for example, lithium metal (Li), lithium sulfide (Li2S), lithium chloride (LiCl), lithium nitride (Li3N), lithium borohydride (LiBH4), lithium fluoroborate (LiBF4), lithium amide (LiNH2), and lithium nitrate (LiNO3), typically in powder form. Examples of solvents include, but are not limited to, aprotic chain hydrocarbons such as heptane, octane, or decane; aromatic hydrocarbons such as benzene, toluene, or xylene; and other solvents that have a low tendency to generate hydrogen sulfide gas in contact with the precursor or final electrolyte composition. The solvent is not particularly limited as long as it does not remain partially or entirely liquid during the milling process and does not participate in harmful reactions with the solid electrolyte precursor or final solid electrolyte composition. The ratios and amounts of the various compounds are not particularly limited as long as their combination enables the synthesis of a desired composition indicated by the presence of specific X-ray diffraction features. Furthermore, the ratios and amounts may be varied depending on the specific synthesis conditions. For example, the ratio of solvent volume to precursor mass may need to be adjusted as the composition of the solid electrolyte is adjusted to ensure complete milling of the precursor and the production of the desired solid electrolyte phase discussed herein.

[0041] The amount of solvent added to the above combination is not limited, as long as it is sufficient to support the synthesis of the desired composition of the solid electrolyte material. Multiple solvents may be mixed with the compounds mentioned. Further materials such as cosolvents or polymers may also be added during this step. Furthermore, the synthesis may be carried out without any solvent.

[0042] Next, in step 230, the composition may be mixed and / or milled for a predetermined time and temperature to produce a solid electrolyte, as described above. The mixing time is not particularly limited, as long as adequate homogenization and reaction of the precursors for producing a solid electrolyte are possible. The mixing temperature is not particularly limited, as long as adequate mixing is possible and the temperature is not so high that the precursors become gaseous. For example, adequate mixing can be achieved over 10 minutes to 48 hours at a temperature of 0 to 120°C. In one embodiment, adequate mixing can be achieved over 10 minutes to 36 hours. In another embodiment, adequate mixing can be achieved over 10 minutes to 24 hours, while in yet another embodiment, adequate mixing can be achieved over 10 minutes to 12 hours. Regarding the temperature at which adequate mixing is performed, in some embodiments, the temperature can be 15 to 200°C. In another embodiment, the temperature at which adequate mixing can be performed is 20 to 150°C. In yet another embodiment, the temperature at which adequate mixing can be performed is 25 to 120°C. Mixing can be achieved, for example, using a planetary ball mill or an attritor mill. In some embodiments, the processes described herein may be referred to as “mechanochemical synthesis.”

[0043] Next, in step 240, the composition may be dried in an inert atmosphere such as argon or nitrogen, or under vacuum, for a predetermined time and temperature. After drying, a heat treatment may be performed during any step 250. The temperature of the heat treatment is not particularly limited, as long as it is above the temperature necessary to produce the crystalline phase of the disclosure, or as long as it is a temperature necessary to improve the ionic conductivity or lithium metal compatibility. The material obtained from the heat treatment step 250 may be a single phase, or it may contain other crystalline phases, glass phases, or very small amounts of precursor phases.

[0044] Generally, the heat treatment time is not limited as long as it allows for the formation of the desired composition and phase. This time can be, for example, in the range of 1 minute to 24 hours. Furthermore, the heat treatment is carried out in an inert gas atmosphere (e.g., argon), a reducing atmosphere (e.g., hydrogen), or under vacuum. The heat treatment step 250 can be completely skipped if the desired composition and phase have been achieved during the preceding mixing or drying step.

[0045] In the final step 260, the completed composition can be used to construct an electrochemical cell such as the cell shown in Figure 1. [Examples]

[0046] Example 1

[0047] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 20.13 g of Li3PS4 and 4.87 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0048] Example 2

[0049] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 20.13 g of Li3PS4 and 4.87 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 6 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0050] Example 3

[0051] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 20.13 g of Li3PS4 and 4.87 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 350 RPM for 6 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0052] Example 4

[0053] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 20.13 g of Li3PS4 and 4.87 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 350 RPM for 3 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0054] Example 5

[0055] The material obtained from Example 4 was collected and subjected to heat treatment. A borosilicate beaker was placed in a fabric heating mantle inside an argon-filled glove box and preheated to 150°C. The powder was placed in the preheated beaker and treated for 10 minutes, then quickly removed from the heating mantle and allowed to cool naturally.

[0056] Example 6

[0057] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 23.13 g of Li3PS4 and 1.87 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0058] Example 7

[0059] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 12.92 g of Li3PS4 and 2.08 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 240 g of zirconia milling medium and 45 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0060] Example 8

[0061] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 12.08 g of Li3PS4 and 2.92 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 240 g of zirconia milling medium and 45 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0062] Example 9

[0063] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 11.01 g of Li3PS4 and 3.99 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 240 g of zirconia milling medium and 45 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0064] Example 10

[0065] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 10.35 g of Li3PS4 and 4.65 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 240 g of zirconia milling medium and 45 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0066] Example 11

[0067] First, Li2S:P2S5=70:30 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 20.49 g of Li2S:P2S5=70:30 and 4.51 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0068] Example 12

[0069] First, Li2S:P2S5=80:20 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 19.71 g of Li2S:P2S5=80:20 and 5.29 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0070] Example 13

[0071] First, Li2S:P2S5=83.3:16.7 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 22.80 g of Li2S:P2S5=83.3:16.7 and 2.20 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0072] Comparative Example 1

[0073] First, Li3PS4 was prepared by mechanochemical synthesis. Next, 4.10 g of Li3PS4 and 0.90 g of LiBH4 were added to an agate mortar and pestle and manually ground for 10 minutes, resulting in a homogeneous mixture. This material was investigated without further processing.

[0074] Comparative Example 2

[0075] The material obtained in Comparative Example 1 was sampled and subjected to heat treatment. A borosilicate beaker was placed in a fabric heating mantle inside an argon-filled glove box and preheated to 140°C. The powder was placed in the preheated beaker and treated for 10 minutes, after which it was quickly removed from the heating mantle and allowed to cool naturally.

[0076] Comparative Example 3

[0077] First, Li3PS4 was prepared by mechanochemical synthesis. Next, an electrolyte composition was prepared from a precursor containing 24.34 g of Li3PS4 and 0.65 g of LiBH4 (Sigma-Aldrich Co.). The precursor was added to a 250 ml zirconia milling jar containing 400 g of zirconia milling medium and 60 ml of xylene (Sigma-Aldrich Co.). The mixture was milled at 500 RPM for 12 hours in a Retsch PM 100 planetary mill. The material was collected and the solvent was removed under vacuum at 70°C.

[0078] In some embodiments, the present disclosure can be realized under various synthesis conditions and stoichiometry, and the examples and data presented herein are intended to aid in understanding the conditions and scope described in the claims. It should be understood that the data presented herein is not exhaustive.

[0079] The effects of the synthesis conditions are demonstrated in Examples 1-4 (Ex 1-4) and Comparative Examples 1-2 (Comp.Ex 1-2). Here, various synthesis conditions are demonstrated through the use of a planetary ball mill, and several observational results can be obtained. When the total energy input to the precursor was reduced during milling, specific changes were observed in X-ray diffraction (Figure 3a), FTIR spectra (Figure 4a), Raman spectra (Figure 5), and conductivity (Figure 6a). The X-ray diffraction peaks may be weakened due to low crystallinity or small crystallite size. Different levels of synthesis energy resulted in differences in the ratio of the X-ray peaks at 14.6±0.25° and 15.3±0.25° (CuKα line), and this ratio may correlate with the ionic conductivity as shown in Figure 6a. When the total energy input reached a certain low threshold, the product became X-ray amorphous, as observed for Example 4 in Figure 3a. X-ray amorphous can refer to glass or nanocrystalline materials whose domains are too small to resolve into peaks, or a combination of the two. If the product of milling synthesis is X-ray amorphous, it can be subjected to heat treatment to induce crystallization and reveal the phase of this disclosure. When the product of Example 4 was exposed to 150°C for 10 minutes to produce Example 5 (Ex 5), substantial crystallization occurred, and the phase of this disclosure was observed.

[0080] Further details regarding the synthesis process can be obtained by examining the FTIR spectra shown in Figure 4a. In Figure 4a, data from Examples 1-5 are shown alongside the spectra of pure Li3PS4 and LiBH4 materials. The LiBH4 spectrum exhibits sharp distinguishing features, and two of these peaks are labeled as representative of this material for comparison with Examples 1-5. Relatively small differences were observed in the FTIR spectra of Examples 1-3. In the materials with the compositions and synthesis conditions described by these examples, the sharp features of LiBH4 were softened and slightly altered, indicating that they formed the phase of this disclosure through incorporation with Li3PS4. This spectrum indicates that the BH4 units remained intact but were placed in a slightly different local environment compared to the environment in LiBH4. Examination of the FTIR spectrum of Example 4 clearly shows the presence of the LiBH4 phase in the product, and the conductivity was low, as shown in Figure 6a. However, the subsequent heat treatment at 150°C for 10 minutes was sufficient to complete the incorporation of LiBH4, crystallize the phase of the disclosure, and improve its conductivity by a factor of six.

[0081] The X-ray diffraction pattern of this disclosure, shown in Figure 3, exhibited the same number and peak positions as typically observed in lithium argyrodite using Br instead of BH4, at the instrument's highest resolution. - (196pm) and BH4 - Considering the similarity of the ionic radii at (193pm), similar d-intervals and peak positions are expected. This suggests the presence of a crystalline phase typically adopted by lithium-based argyrodite materials. The only atypical peak observed in the X-ray diffraction data is at 14.4 ± 0.25 degrees, the presence and significance of which will be discussed in detail elsewhere in this disclosure.

[0082] When the Raman spectra of Examples 1-3 shown in Figure 5 were examined, the result was 423 cm⁻¹. -1 The main peak is 391cm. -1 It was observed along with a minor peak. 391cm -1The peak is P2S6, an impurity phase introduced into the synthesis along with the Li3PS4 precursor. 4- This corresponds to PS vibrations in units. Importantly, this Raman spectrum is at 423 cm⁻¹. -1 The main peak was on PS4. 3- This corresponds to PS vibrations in structural units. The crystal structure of argyrodite-type materials is composed mainly of PS4 units, and other units (P2S6) 4- P2S7 4- (etc.) are not present in the structure. The observed X-ray diffraction pattern shows a number and position of peaks typical of argyrodite-type materials, and the Raman spectrum shows that PS4 local structural units are predominantly present, so it can be concluded that the material of this disclosure is also predominantly an argyrodite-type material.

[0083] Further details of the Raman spectra for Examples 1-3 are shown in the inset of Figure 5. Here, 452 cm⁻¹ is shown. -1 A variation in the shoulder peak was observed. The intensity of this peak appeared to correlate with the energy input during milling synthesis, and it is noteworthy that this peak intensity may also correlate with conductivity. This peak may indicate a small structural hindrance that alters local crystal symmetry affecting ion mobility.

[0084] Comparative Examples 1 and 2, shown in Figure 3a, demonstrate that simply mixing Li3PS4 and LiBH4 precursor phases and applying heat is insufficient to produce the phase of this disclosure, and that further synthesis energy input, such as alternative reaction pathways including milling or solution-phase reactions, would be necessary.

[0085] In other embodiments, other synthesis routes may be used. To synthesize the solid electrolyte material described herein, for example, a method may be used that includes mixing a plurality of suitable precursors providing components Li, T, X, and A in a solvent capable of inducing reactions between the precursors, removing the solvent, and optionally heat-treating the material at a temperature above its crystallization temperature.

[0086] Other embodiments of the present disclosure relate to the nominal stoichiometric range within which the present disclosure can be realized. Examples 6 - 10 (Ex 6 - 10) and Comparative Example 3 (Comp. Ex 3) serve as demonstrations regarding the range of the fraction of LiBH4 in the precursor. Generally, the present disclosure has been demonstrated for LPS·zLiBH4 where 0.25 < z < 4. Examples 6 - 10 demonstrate this range, and the resulting diffraction patterns are shown in Figure 3b. In all cases, the peaks of the present disclosure were observed. Comparative Example 3 showed the results when z = 0.2. Since the amount of LiBH4 available in this system was too low for the crystal phase of the present disclosure to be substantially formed, only the peaks of the Li3PS4 precursor phase were observed.

[0087] Examining the conductivity trends of Examples 6 - 10 shown in Figure 6b, it was observed that the conductivity increased from z = 0.7 to z = 3 and then decreased when the LiBH4 content was further increased to z = 3.7. Briefly stated, the conductivity increases up to a limit as the fraction of LiBH4 in the system increases, and then the conductivity begins to decrease.

[0088] For Examples 6 - 8, the FTIR spectra shown in Figure 4b showed B - H bonds slightly different from those seen in pure LiBH4. Examples 6 - 8 had no characteristics of LiBH4. However, the spectra of Examples 9 - 10 clearly showed the further presence of characteristic peaks of the LiBH4 phase. The presence of the LiBH4 phase indicated that, in the nominal compositions reported in Examples 9 - 10, the fraction of LiBH4 in the precursor was too high to be incorporated into a single phase.

[0089] The nominal composition of Example 8 corresponds to Li5PS4(BH4)2. The data presented in this disclosure illustrate how this disclosure can be described as an argyrodite-type phase. Under the understanding that a typical argyrodite-type material exists in space group F-43m, Wyckoff positions 4a and 4d likely contain chalcogens (typically sulfur), halogens (typically Cl or Br), or pseudohalogens. Considering a hypothetical example containing the pseudohalogen BH4, if half of the available 4a+4d sites are filled with BH4, the nominal stoichiometry of the resulting argyrodite-type material is Li6PS5(BH4). Subsequently, if all of the available 4a+4d sites are filled with BH4, the nominal stoichiometry of the resulting argyrodite-type material is Li5PS4(BH4)2. Therefore, the limit of incorporating halogens or pseudohalogens into argyrodite-type materials is Li + (12-n-y) T n+ A 2- (6-y) X - (y) This would be the case where y=2. Beyond this level, there is essentially no place in the structure for halogens or pseudohalogens to be present while remaining energetically favorable.

[0090] Figure 4b shows that the FTIR data is Li + (12-n-y) T n+ A 2- (6-y) X - (y) The presence of LiBH4 is shown only for nominal compositions where y > 2. Based on this observation, this disclosure is the first to realize an argyrodite-type material in which a halogen or pseudohalogen occupies substantially all of the 4a and 4d Wyckoff sites, essentially resulting in halogen or pseudohalogen saturation of the above structure. The realization of this argyrodite-type material has been extensively attempted with halogens such as Cl and Br, but has not been achieved. The realization of this argyrodite-type material is Li + (12-n-y) T n+ A 2-(6-y) X - (y) It would be due to the unique properties of pseudo-halogens such as BH4 that enable y = 2 in X and the discovery of the present disclosure.

[0091] Another embodiment of the present disclosure relates to a further range of nominal stoichiometries in which the present disclosure can be realized. Using the system (Li2S:P2S5):2LiBH4, the range of the Li2S:P2S5 ratio was compared by Examples 1 and Examples 11 - 13 (Ex 11 - 13). In such an embodiment, the nominal composition of the Li2S:P2S5 fraction was varied from 70:30 at the lower end to 83:17 at the upper end. The general observations from the X-ray diffraction results shown in Figure 3c include the variation in the ratio of the peak at 14.6° ± 0.25° to the peak at 15.3° ± 0.25°, and the amount of relative Li2S impurities. In the composition of Li2S:P2S5 = 80:20 shown in Example 12, it approached the limit of the glass formation ratio, and an increase in the amount of Li2S was observed. However, in Figure 6c, an increase in conductivity was generally observed up to this limit. In the case of the composition of Li2S:P2S5 = 83:17, Li2S was present in excess by X-ray diffraction, and this composition may be outside the range of the glass formation ratio, and also due to the stoichiometric imbalance of the system and the strong presence of the Li2S impurity phase, the conductivity decreased.

[0092] In another embodiment, there may be a peak centered at 2θ = 14.6° ± 0.25°. This peak may be a component of the main structure or secondary phase of the composition. The presence of this peak is associated with an increase in ionic conductivity and is therefore desirable when high lithium conductivity is required. Component X is BH4 - , BF4 - When it is a polyanion species such as, this additional peak may result from the rotation or displacement of the polyhedron group, and the vertex species (H, F, etc.) occupy regions not normally occupied by the crystal structure. When component X is the only anion (Cl - , Br -When it is (such as), new diffraction peaks that are not seen occur. Whether this diffraction peak is due to the polyanion species itself or due to new scattering induced by the relaxation and rearrangement of the surrounding structure to compensate for the movement of the polyanion and the movement of lithium ions. Since the rotation and displacement of the polyhedron often correlate with the mobility of ionic charge carriers, the correlation between ionic conductivity and the intensity of this measurable diffraction peak can be understood by considering that the intensity of the peak itself is related to the rotation and displacement of the anionic polyhedron.

[0093] The general chemical composition can be expressed as LPS·zLiX, where T, A, and X represent the elements as described in this disclosure, and LPS represents, for example, a mixture of Li2S and P2S5 in a glass-forming ratio, and / or a mixture of Li2S and B2S3 in a glass-forming ratio. The glass-forming ratio can be in the range of 1:1 to 4:1 for Li2S:P2S5 and 1:1 to 3:1 for Li2S:B2S3. In another embodiment, as long as the mixing and / or grinding step is sufficient to thoroughly combine this material with other precursors in a way that enables the formation of the desired electrolyte composition, the Li2S:P2S5 component may be mainly crystalline or mainly glassy.

[0094] The composition can be within the range of 0 < z ≤ 25. In another embodiment, the composition can be within the range of 0.15 ≤ z ≤ 15. In a further embodiment, the composition can be within the range of 0.20 ≤ z ≤ 10. In yet another embodiment, the composition can be within the range of 0.25 ≤ z ≤ 4. In yet another embodiment, the composition can be within the range of 1 ≤ z ≤ 3. The above composition may be a single phase or a mixed phase, and other crystal phases are identified by XRD peaks at 2θ = 17.5° and 18.2°. The above composition may also contain a crystal phase related to one or more lithium halides or lithium sulfides. As is commonly seen in sulfide materials, the above composition may be a "glass-ceramic" in which both a crystal phase and a glass phase coexist.

[0095] In another embodiment, the general chemical composition can be represented as LPSX·zLiX, where LiX includes one or more of LiCl, LiBr, LiI, LiBH4, LiBF4, LiNH2, and LiNO3, and LPSX includes a mixture of Li2S, P2S5, and LiX in a glass-forming ratio, and a mixture of Li2S, B2S3, and LiX in a glass-forming ratio. In some embodiments, "X" in LPSX and "X" in LiX are the same, and in another embodiment, "X" in LPSX and "X" in LiX are not the same. The glass-forming ratio can be in the range of 1:1:1 to 4:1:4 for Li2S:P2S5:LiX and 1:1:1 to 3:1:4 for Li2S:B2S3:LiX. In some embodiments, LiX includes LiBH4, LiBF4, LiNH2, and LiNO3. In another embodiment, LiX is LiBH4. The composition can be within the range of 0 < z ≤ 25. In another embodiment, the composition can be within the range of 0 < z ≤ 15. In a further embodiment, the composition can be within the range of 0 < z ≤ 10. In yet another embodiment, the composition can be within the range of 0 < z ≤ 4. In yet another embodiment, the composition can be within the range of 0 < z ≤ 2. The above composition can be a single phase or a mixed phase, and other crystalline phases are identified by XRD peaks at 2θ = 17.5° and 18.2°. The above composition may also include a crystalline phase related to one or more lithium halides or lithium sulfides. As is commonly seen in sulfide materials, the above composition may be a "glass-ceramics" in which both a crystalline phase and a glass phase coexist.

[0096] In X-ray diffraction (XRD) measurements using Cu-Kα(1,2)=1.5418 Å, the ratio of peak heights between the peaks at 2θ=15.3°±0.25° and 14.6°±0.25° can be 25:1 or less. In another embodiment, the ratio of peak heights between the peaks at 2θ=15.3°±0.25° and 14.6°±0.25° in X-ray diffraction (XRD) measurements using Cu-Kα(1,2)=1.5418 Å can be 20:1 or less. In yet another embodiment, the ratio of peak heights between the peaks at 2θ=15.3°±0.25° and 14.6°±0.25° in X-ray diffraction (XRD) measurements using Cu-Kα(1,2)=1.5418 Å can be 10:1 or less. In yet another embodiment, the ratio of peak heights between the peaks at 2θ = 15.3°±0.25° and 14.6°±0.25° in X-ray diffraction (XRD) measurements using Cu-Kα(1,2)=1.5418 Å can be 5:1 or less. In yet another embodiment, the ratio of peak heights between the peaks at 2θ = 15.3°±0.25° and 14.6°±0.25° in X-ray diffraction (XRD) measurements using Cu-Kα(1,2)=1.5418 Å can be 2:1 or less. In yet another embodiment, the ratio of peak heights between the peaks at 2θ = 15.3°±0.25° and 14.6°±0.25° in X-ray diffraction (XRD) measurements using Cu-Kα(1,2)=1.5418 Å can be 1.5:1 or less. Furthermore, these peaks may be separated by 0.3° or more.

[0097] An exemplary composition is defined as LPS·2LiX=Li5PS4(BH4)2. Such a composition results in the semicrystalline phase of this disclosure. The structure of this semicrystalline phase contributes to high ionic conductivity, and the presence of hydride components can help form a stable, low-resistance interface with lithium metal and high-voltage cathode active material.

[0098] The crystalline or semi-crystalline phases obtained from compositions such as Li5PS4(BH4)2 can adopt the typical cubic structure of lithium argyrodite with the space group F-43m, or a very similar structure with a slightly changed symmetry. The reason for the change in symmetry was described above in terms of how the rotation and displacement of the polyanion component can result in the atomic occupation of lattice sites that are not explicitly occupied within the framework of the F-43m space group. Adopting this type of structure is not obvious. Considering the chemical system Li 7-y PS 6-y X y When considering X = Cl, the solid solubility limit is y = 1.5. Since the ionic radius of Br is larger than that of Cl, this limit was shown to be lower for X = Br at y = 1.25 [Nazar, Angewandte Chemie, 2019]. The ionic radius of BH4 - is similar to that of Br - , so it is expected that the solid solubility limit can be y ≤ 1.25. However, in the present disclosure where BH4 is used as a pseudohalogen, this limit is y > 1.25, as is clear from the conductivity trends and the absence of the LiBH4 phase in X-ray diffraction and FTIR spectroscopy. Furthermore, the known compound Ag5PS4Cl2 [Jorgens, Solid State Sciences, 2007] adopts an orthorhombic structure (Amm2), which is very different from the cubic lithium argyrodite family (F-43m), and lithium analogs of this composition are not currently known. Therefore, the present disclosure will constitute the first example of a lithium ion conductor having a cubic argyrodite structure with a halogen or pseudohalogen level approaching y = 2 in Li 7-y PS 6-y X y .

[0099] In another embodiment, the LPS·yLiX system can yield a crystalline fraction having the nominal composition Li5PS4(X)2, along with a glassy fraction. The ratio of the crystalline fraction to the glassy fraction will be determined by the nominal starting composition. The glassy fraction may contain an ion-conducting material and may have a composition similar to that of the LPS precursor. If the amount of LiX is greater than the amount that can be supported by the amount of LPS, the resulting material may include the Li5PS4(X)2 crystalline fraction, glassy or crystalline LiX, and further glass phases. In some embodiments, LiX may be LiBH4, in which case component X is BH4.

[0100] The improved conductivity of this disclosure compared to related technologies is likely due to a unique ionic conduction mechanism. For example, BH4 - The polyanionic nature of the anion enables a "paddle-wheel" effect, where the rotational degrees of freedom of the anionic unit allow for easier passage of lithium ions through changes in local potential energy space during rotation. Furthermore, the compositions presented in this disclosure, as observed by low-intensity XRD patterns with broadened peaks, for example, BH4 - The disorder introduced by anions can be beneficial. In the case of Cl-containing argyrodites and Br-containing argyrodites, the disorder between S and Cl / Br sites results in high conductivity, while in the case of I-containing argyrodites, the absence of such disorder is known to result in low conductivity. In this invention, the presence of such disorder or localized lattice strain near the BH4 unit likely results in high ionic conductivity.

[0101] Furthermore, the present disclosure may be nanocrystals having crystal domain sizes on the order of 100 nm or less. This may be due to processing conditions or reaction mechanisms between precursors. This may also provide advantages for ionic conductivity and operation at high current densities using lithium metal anodes. The nanocrystalline domains allow for more uniform SEI to be expressed at the interface with the lithium metal anode, which would be beneficial for supporting high current densities without dendrite nucleation and growth.

[0102] Apart from considerations of microstructure, the improved stability compared to compositions of related technologies when used in combination with metallic lithium anodes will likely stem from several factors related to the chemical properties of the above materials. In particular, in embodiments containing hydride or amide species, the SEI formed in contact with the lithium metal may have low overall resistance to charge transfer due to the presence of moderately conductive lithium-hydride species and dilution of poorly conductive lithium sulfide species. The arrangement and structure of the SEI components may be such that they result in a more uniform electric field distribution, ion flux, and / or lithium plating / stripping. Furthermore, the surface energy of the composition may be such that it achieves good wetting by the lithium metal and / or maintains mechanical contact during higher levels of interfacial polarization or plating / stripping rates. In this context, "improved stability" may mean the use of high current densities without unexpected voltage deviations or short circuits, or longer cycle life, or higher Coulomb efficiency. Examples of "low voltage" anode active materials include lithium metal, lithium alloys, Si, Sn, graphite carbon, hard carbon, composites thereof, or 1.0V vs. Li / Li + Other materials or composites having an operating voltage close to or lower than this may be included, but are not limited to, this.

[0103] It has been observed that structural modifications or the introduction of a second phase can lead to an increase in ionic conductivity. These modifications can be controlled during the synthesis process by controlling the milling temperature or the total energy input to the precursor composition.

[0104] Gases may be generated during synthesis. The presence of gas species indicates that the final composition may differ slightly from the nominal starting composition. Gas generation may be related to specific synthesis conditions and may also be related to the observation of the aforementioned structural modifications or the formation of a second phase.

[0105] The above-mentioned structural modifications or the presence of a second phase are associated with a decrease in the performance of the lithium metal anode. This is thought to be because the chemical changes associated with the synthesis, as demonstrated by gas generation during milling synthesis, lead to changes in the composition and properties of the SE-Li interface. Therefore, in order to achieve the best performance when using a lithium metal anode, it would be desirable to synthesize the composition of the present invention under conditions that minimize the above-mentioned structural modifications or the presence of a second phase.

[0106] When used as part of a positive electrode active material layer in combination with a high-voltage cathode active material, the composition of the present invention offers stability advantages that may stem from its chemical properties or structure compared to compositions of related technologies. For example, BH4 - Or BF4 - The incorporation of "superhalogens" such as these can lead to an overall increase in the oxidation potential of the electrolyte composition due to their high electron affinity.

[0107] The features described above and those described in the following claims can be combined in various ways without departing from their respective scopes. The above examples illustrate several possible, non-limiting combinations. Therefore, it should be noted that matters included in the above description or shown in the accompanying drawings should be interpreted as illustrative and not limiting. The above embodiments should be considered as examples of the invention rather than limiting the scope of the invention. By examining the detailed description and accompanying drawings in addition to the above embodiments of the invention, it will be found that other embodiments of such invention exist. Therefore, many combinations, substitutions, modifications and improvements of the above embodiments of the invention that are not expressly specified in this disclosure also fall within the scope of this disclosure. The following claims are intended to cover all descriptions of the general and specific features described herein, as well as any descriptions of the scope of the Method and System that may be said to fall somewhere in between as a matter of language. Some embodiments of the invention related to the present invention are shown below. [Embodiment 1] An argyrodite-type solid electrolyte material containing Li, T, X, and A, where T is at least one element selected from the group consisting of P, As, Si, Ge, Al, and B, and X is one or more halogens or BH 4 , BF 4 , NH 2 or NO 3 or a combination thereof, and A is one or more of S, Se, and N. The solid electrolyte material has peaks at 2θ = 14.6° ± 0.25°, 15.3° ± 0.25°, and 25.1° ± 0.25° in X-ray diffraction measurement using Cu-Kα(1,2) = 1.5418 Å, an argyrodite-type solid electrolyte material. [Embodiment 2] Furthermore, the solid electrolyte material according to Embodiment 1, which contains at least one of a glass-ceramics phase, a crystal phase, and a mixed phase. [Embodiment 3] The solid electrolyte material according to Embodiment 1, where the ratio of the intensity of the peak at 2θ = 15.3° ± 0.25° to the intensity of the peak at 2θ = 14.6° ± 0.25° is 5:1 or less. [Embodiment 4] The solid electrolyte material according to Embodiment 1, where X consists of a combination of one or more halogens or BH 4 , BF 4 , NH 2 or NO 3 . [Embodiment 5] Containing the formula LPS·zLiX, where LPS represents a mixture of Li 2 S and P 2 S 5 in a glass-forming ratio, or a mixture of Li 2 S and B 2 S 3 in a glass-forming ratio, and LiX represents LiCl, LiBr, LiI, LiBH 4 , LiBF 4 , LiNH 2 and LiNO 3, and 0.25 ≤ z ≤ 4, the solid electrolyte material according to Embodiment 1. [Embodiment 6] Containing the formula LPSX·zLiX, where LPSX contains a mixture of Li 2 S, P 2 S 5 and LiX in a glass-forming ratio, or a mixture of Li 2 S, B 2 S 3 and LiX in a glass-forming ratio, where LiX contains one or more of LiCl, LiBr, LiI, LiBH 4 , LibF 4 , LiNH 2 and LiNO 3 , and 0 < z ≤ 25, the solid electrolyte material according to Embodiment 1. [Embodiment 7] The solid electrolyte material according to Embodiment 1, where X contains BH 4 , and the presence of the peak at 2θ = 14.6° ± 0.25 in X-ray diffraction measurement using Cu-Kα(1,2) = 1.5418 Å is controlled by adjusting specific synthesis conditions without changing the nominal stoichiometry. [Embodiment 8] The formula Li + (12-n-y) T n+ A 2- (6-y) X - (y) A solid electrolyte material according to Embodiment 1, comprising, where y > 1. [Embodiment 9] Formula Li + (12-n-y) T n+ A 2- (6-y) X - (y) This includes, where T=P, A=S, and X=BH 4 The solid electrolyte material according to Embodiment 1, wherein y > 1. [Embodiment 10] X-ray diffraction measurements using Cu-Kα(1,2)=1.5418Å revealed a crystalline phase with peaks at 2θ=14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25°, and LiBH 4 LiBF 4 , CINH 2 LiNO 3 The solid electrolyte material according to Embodiment 1, comprising a mixture of one or more of LiSCN and LiOCN. [Embodiment 11] The solid electrolyte material according to Embodiment 1, comprising a crystalline argyrodite-type phase that constitutes 50 mol% or more of the total phase present. [Embodiment 12] In Raman spectroscopy measurements using 12.532 nm excitation, the main peak was 423 ± 10 cm⁻¹. -1 It is located at an intensity ratio of at least 2:1, with other peaks ranging from 250 to 700 cm. -1 A solid electrolyte material according to Embodiment 1, which exists within the range of [specify range]. [Embodiment 13] The solid electrolyte material according to Embodiment 2, wherein the ratio of the peak intensity at 2θ=15.3° to the peak at 2θ=17.5° is 1 or more. [Embodiment 14] Lithium batteries, including the following: (a) A positive electrode active material layer containing positive electrode active material, (b) a negative electrode active material layer containing a negative electrode active material, and (c) A solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, Here, at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises a sulfide solid electrolyte material containing an algyrodite-type solid electrolyte material comprising Li, T, X, and A, where T is at least one element selected from the group consisting of P, As, Si, Ge, Al, and B, and X is one or more halogens or BH 4 BF 4 NH 2 Or NO 3 Or a combination thereof, where A is one or more of S, Se, and N, and the solid electrolyte material has peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurements using Cu-Kα(1,2)=1.5418Å. [Embodiment 15] A method for manufacturing a solid electrolyte material, Element A or compound Li 2 A or Li 3 The process involves mixing and milling a raw material composition containing N, element T or T sulfide, and compound LiX until the precursor material is substantially amorphous or alloyed to produce a final sulfide glass composition, and optionally heating the sulfide glass at a heat treatment temperature above the crystallization temperature of the material to synthesize glass ceramics having peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° as measured by X-ray diffraction using Cu-Kα(1,2) = 1.5418 Å. The solid electrolyte material includes glass ceramics containing Li, T, X, and A. T is at least one of P, As, Si, Ge, Al, and B, and X is a halogen and / or BH 4 BF 4 NH 2 Or NO 3 A method for producing a solid electrolyte material, wherein A is at least one of S, Se, and N. [Embodiment 16] The method according to Embodiment 15, wherein the ratio of the peak intensity at 2θ=15.3° to the peak at 2θ=17.5° is 1 or more. [Embodiment 17] A method for producing a solid electrolyte material, comprising mixing a suitable precursor containing components Li, T, X, and A in a solvent capable of causing a reaction between the precursors, removing the solvent, and optionally heat-treating the material at a temperature above its crystallization temperature, wherein the solid electrolyte material comprises a glass ceramic containing Li, T, X, and A, where T is at least one of P, As, Si, Ge, Al, and B, and X is a halogen and / or BH 4 BF 4 NH 2 Or NO 3 A method for producing a solid electrolyte material, wherein A is at least one of S, Se, and N.

Claims

1. Algyrodite-type solid electrolyte material, comprising Li, P, BH ４ An argyrodite-type solid electrolyte material comprising and S, wherein the solid electrolyte material has peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurements using Cu-Kα(1,2) = 1.5418 Å, and the ratio of the intensity of the peak at 2θ = 15.3°±0.25° to the peak at 2θ = 14.6°±0.25° is 5:1 or less.

2. Furthermore, the solid electrolyte material according to claim 1 comprises at least one of a glass ceramic phase, a crystalline phase, and a mixed phase.

3. The formula LPS·zLiX contains, where LPS is the glass formation ratio of Li ２ S and P ２ S ５ It represents a mixture of LiX and LiBH. ４ The solid electrolyte material according to claim 1, wherein 0.25 ≤ z ≤ 4.

4. Comprising the formula LPSX·zLiX, where LPSX is Li in the glass formation ratio ２ S and P ２ S ５ and a mixture of LiX, where LiX contains LiBH ４ The solid electrolyte material according to claim 1, comprising 0 < z ≤ 25.

5. X is BH ４ The solid electrolyte material according to claim 1, wherein the presence of a peak at 2θ = 14.6° ± 0.25 in X-ray diffraction measurements using Cu-Kα(1,2) = 1.5418 Å is controlled by adjusting specific synthesis conditions without changing the nominal stoichiometry.

6. Formula Li ＋ （１２－ｎ－ｙ） T ｎ＋ A ２－ （６－ｙ） X － （ｙ） This includes, where T=P, A=S, and X=BH ４ The solid electrolyte material according to claim 1, wherein y > 1.

7. X-ray diffraction measurements using Cu-Kα(1,2) = 1.5418 Å revealed a crystalline phase with peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25°, and LiBH ４ LiBF ４ LiNH ２ LiNO ３ The solid electrolyte material according to claim 1, comprising a mixture of one or more of LiSCN and LiOCN.

8. The solid electrolyte material according to claim 1, comprising a crystalline argyrodite-type phase that constitutes 50 mol% or more of the total phase present.

9. In Raman spectroscopy measurements using 12.532 nm excitation, the main peak was 423 ± 10 cm⁻¹. －１ It is located at an intensity ratio of at least 2:1, with other peaks ranging from 250 to 700 cm. －１ A solid electrolyte material according to claim 1, which is located within the range.

10. The solid electrolyte material according to claim 2, wherein the ratio of the peak intensity at 2θ = 15.3° to the peak at 2θ = 17.5° is 1 or more.

11. Lithium batteries, including the following: (a) A positive electrode active material layer containing positive electrode active material, (b) A negative electrode active material layer containing a negative electrode active material, and (c) A solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, Here, at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is made of Li, P, BH ４ The solid electrolyte material includes an argyrodite-type solid electrolyte material containing S, and the solid electrolyte material has peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurements using Cu-Kα(1,2) = 1.5418 Å, and the ratio of the intensity of the peak at 2θ = 15.3°±0.25° to the peak at 2θ = 14.6°±0.25° is 5:1 or less.

12. Li, P, BH ４ A method for producing an argyrodite-type solid electrolyte material containing S, S or compound Li ２ S, element P or P sulfides, and compound LiBH ４ A method for producing an argyrodite-type solid electrolyte material, comprising mixing and milling a raw material composition containing the above until the precursor material is substantially amorphous or alloyed to produce a final sulfide glass composition, thereby synthesizing a glass ceramic having peaks at 2θ = 14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° as measured by X-ray diffraction with Cu-Kα(1,2) = 1.5418 Å, and having an intensity ratio of 5:1 or less between the peak at 2θ = 15.3°±0.25° and the peak at 2θ = 14.6°±0.25°.

13. The method according to claim 12, further comprising heating the sulfide glass at a heat treatment temperature equal to or greater than the crystallization temperature of the solid electrolyte material.

14. The method according to claim 12, wherein the ratio of the peak intensity at 2θ = 15.3° to the peak at 2θ = 17.5° is 1 or more.

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