Solid electrolyte material and solid battery manufactured using the same

Abstract

The solid electrolyte material contains Li, T, X, and A, where T is at least one of P, As, Si, Ge, Al, Sb, W, and B, X is one or more halogens and / or N, and A is one or more of S or Se. The solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418Å, and may contain glass ceramics and / or mixed crystalline phases.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 62 / 990,135, filed March 16, 2020, the contents of which are incorporated herein by reference in their entirety. Technical Field Various embodiments described in this disclosure relate to the fields of solid state primary and secondary electrochemical cells, electrodes and electrode materials, electrolytes and electrolyte compositions, and corresponding methods of making and using the same. [Background technology]

[0002] The increasing number and diversity of mobile devices, the evolution of hybrid / electric vehicles, and the development of Internet-of-Things devices are driving the need for battery technologies with improved reliability, capacity (Ah), thermal properties, lifespan, and rechargeability. Currently, lithium solid-state battery technology offers potential improvements in safety, packaging efficiency, and enables novel high-energy chemistries, but further improvements are needed.

[0003] In electrochemical cells, iodine-containing materials can provide stability to lithium metal anodes [Rangasamy, E.; Liu, Z.; Gobet, M.; Pilar, K.; Sahu, G.; Zhou, W.; Wu, H.; Greenbaum, S.; Liang, C. An Iodide-Based Li7P2S8I Superionic Conductor. J Am Chem Soc 2015, 137 (4), 1384-1387.] However, the most common iodine-containing solid electrolyte (Li6PS5I) has low conductivity (1E-4 mS / cm at room temperature) [Boulineau, S.; Courty, M.; Tarascon, J.-M.; Viallet, V. Mechanochemical Synthesis of Li-Argyrodite Li6PS5X (X=Cl, Br, I) as Sulfur-Based Solid Electrolytes for All Solid State Batteries Application. Solid State Ionics 2012, 221, 1-5.]

[0004] Furthermore, common electrolytes for electrochemical cells, such as those of the argyrodite family, require high-temperature (500°C) heat treatment to obtain highly conductive crystalline materials [Boulineau et al, Solid State Ionics 2012, 221, 1-5]. This high-temperature processing adds complexity and cost to the fabrication of solid electrolytes and electrochemical cells. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, there is a need for electrochemical cells that have excellent electrical conductivity and are economically manufactured. The present disclosure addresses this need by describing such solid electrolyte materials and methods of manufacture. [Means for solving the problem]

[0006] In one embodiment, the solid electrolyte material comprises the elements Li, T, X, and A, where T is at least one element selected from the group consisting of P, As, Si, Ge, Al, Sb, W, and B, X is at least one element selected from the group consisting of F, Cl, Br, I, and N, and A is at least one of the elements S and Se. The solid electrolyte material has peaks at 2θ=14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å, and may contain glass ceramics and / or mixed crystalline phases.

[0007] The present disclosure will be understood by reference to the following detailed description in conjunction with the drawings, which are briefly described below: It should be noted that for illustrative clarity, certain elements in the drawings may not be drawn to scale. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view of an exemplary structure of a lithium solid-state electrochemical cell including a solid electrode composition, according to one embodiment.

[0009] [Figure 2] FIG. 2 is a flow chart of a process for producing a solid electrolyte composition, according to one embodiment.

[0010] [Figure 3] FIG. 3 is a plot of an X-ray diffraction measurement of a solid electrolyte composition produced by the process shown in FIG. 2, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the following description, specific details are provided to provide a thorough understanding of various embodiments of the present invention. However, upon reading and understanding the specification, claims, and drawings, those skilled in the art will understand that some embodiments of the present disclosure may be practiced without following some of the specific details set forth in the present disclosure. Moreover, in order to avoid obscuring the present disclosure, some well-known methods, processes, devices, and systems that are expected to be applicable to the various embodiments described in the present disclosure are not disclosed in detail.

[0012] 1 is a schematic cross-sectional view showing one exemplary structure of a lithium solid-state electrochemical cell including an electrode composition of the present disclosure. The lithium solid-state 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 described in the present disclosure may form portions of the positive electrode active material layer 120, the negative electrode active material layer 140, and the solid electrolyte layer 130.

[0013] The positive electrode 110 may be formed from a material such as, but not limited to, aluminum, nickel, titanium, stainless steel, or carbon. Similarly, the negative electrode 150 may be formed from a material such as, but not limited to, copper, nickel, stainless steel, or carbon. The negative electrode 150 may be omitted entirely if the negative electrode active material 140 has sufficient electronic conductivity and mechanical strength. The positive electrode active material layer 120 may include at least a positive electrode active material such as, but not limited to, a metal oxide, a metal phosphate, a metal sulfide, sulfur, lithium sulfide, oxygen, or air, and may further include a conductive material and / or binder, such as a solid electrolyte material, e.g., a solid electrolyte composition described herein. Examples of conductive materials include, but are not limited to, carbon (carbon black, graphite, carbon nanotubes, carbon fibers, 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 described herein. The thickness of the positive electrode active material layer 120 can be, for example, within a range of 1 μm to 1000 μm.

[0014] The negative electrode active material layer 140 may include at least a negative electrode active material such as, but not limited to, lithium metal, a lithium alloy, silicon (Si), tin (Sn), graphite carbon, or hard carbon, and may further include a conductive material and / or a binder, such as a solid electrolyte material, for example, a solid electrolyte composition described herein. Examples of conductive materials include materials used in positive electrode material layers. Examples of binders include materials used in positive electrode material layers. The negative electrode active material layer 140 may include, for example, 5% to 80% by volume of the solid electrolyte composition described herein. The thickness of the negative electrode active material layer 140 may be, for example, within a range of 1 μm to 1000 μm.

[0015] The solid electrolyte material contained in the solid electrolyte layer 130 is the solid electrolyte composition described in this disclosure. The solid electrolyte layer 130 may contain, for example, 10% to 100% by volume of the solid electrolyte composition described in this disclosure. Furthermore, the solid electrolyte layer 130 may contain a binder or other modifier. Examples of binders include an additional self-healing polymer and poly(ethylene) oxide (PEO) in addition to the material used in the positive electrode layer. The thickness of the solid electrolyte layer 130 is in the range of 1 μm to 1000 μm.

[0016] Although shown as a lamellar structure in Figure 1, it is well known that other shapes and configurations of solid-state electrochemical cells are possible. Most commonly, a lithium solid-state battery can be fabricated by sequentially stacking a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer and pressing them between the electrodes to provide a housing.

[0017] FIG. 2 is a flow chart of a process for producing a solid electrolyte composition useful in constructing secondary electrochemical cells. Process 200 begins with preparation step 210, where optional preparation operations such as precursor synthesis, purification, and device preparation may be performed. After any initial preparation, process 200 proceeds to step 220, where sulfur compounds, lithium compounds, and other compounds as described herein may be combined with appropriate solvents and / or other liquids. 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 bromide (LiBr), and lithium iodide (LiI), typically in powder form. Exemplary solvents include, but are not limited to, aprotic chain hydrocarbons such as heptane, aromatic hydrocarbons such as xylene, and other solvents with a low tendency to generate hydrogen sulfide gas upon contact with the precursors and the final electrolyte composition. The solvent is not particularly limited, so long as it remains partially or completely liquid during the milling process at the desired milling temperature and does not adversely react with the solid electrolyte precursor or the final solid electrolyte composition. The ratios and amounts of the various compounds are not particularly limited, so long as the combination allows for the synthesis of the desired composition and phase, as indicated by the presence of specific X-ray diffraction features. Furthermore, the ratios and amounts may vary depending on the specific synthesis conditions. For example, the ratio of solvent volume to precursor mass may need to be adjusted as the solid electrolyte composition is adjusted to ensure complete milling of the precursor to produce the desired solid electrolyte phase discussed in this disclosure.

[0018] The amount of solvent added to the above combination is not limited as long as it supports the synthesis of the desired composition of the solid electrolyte material. Multiple solvents may be mixed with the mentioned compounds. Additional materials, such as cosolvents or polymers, may also be added during this step. Furthermore, the synthesis may be performed without a solvent.

[0019] 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, so long as it allows for adequate homogenization and reaction of the precursors to produce a solid electrolyte. The mixing temperature is not particularly limited, so long as it allows for adequate mixing and is not so high that the precursors become gaseous. For example, adequate mixing can be achieved at a temperature of 20 to 120°C for 10 minutes to 60 hours. Mixing can be achieved, for example, using a planetary ball mill or an attritor mill.

[0020] Next, in step 240, the composition may be dried for a predetermined time and temperature in an inert atmosphere, such as argon or nitrogen, or under vacuum. After drying, a heat treatment to crystallize the dried material may be performed during step 250. The temperature of the heat treatment is not particularly limited, as long as it is equal to or higher than the crystallization temperature required to produce the crystalline phases of the present disclosure. The material resulting from heat treatment step 250 may be single-phase or may contain other crystalline and amorphous phases, as well as minor amounts of precursor phases. The described process requires only a mild heat treatment at 200-220°C.

[0021] Generally, the heat treatment time is not limited as long as it allows the production of the desired composition and phase. The time can be, for example, within the range of 1 minute to 24 hours. Furthermore, the heat treatment is carried out in an inert gas atmosphere (e.g., argon) or under vacuum.

[0022] In a final step 260, the completed composition can be utilized in the construction of an electrochemical cell, such as the cell of FIG.

[0023] Other synthetic routes can be used as well. For example, the solid electrolyte materials described herein may be synthesized using a method that includes mixing appropriate precursors that provide the components Li, T, X, and A in a solvent that can cause a reaction between the precursors, removing the solvent, and heat treating at a temperature above the crystallization temperature of the material.

[0024] An exemplary embodiment is a method for producing a sulfide solid electrolyte material including a glass ceramic containing Li, T, X, and A (T is at least one element selected from the group consisting of P, As, Si, Ge, Al, Sb, W, and B, X is at least one element selected from the group consisting of F, Cl, Br, I, and N, and A is at least one element of S or Se), the method comprising: (a) mixing element A or a compound LiA, element T or a sulfide of T, and compound LiX or (b) mixing and milling a raw material composition containing LiN to form a sulfide glass that is amorphous under X-ray diffraction; and (b) heating the sulfide glass at a heat treatment temperature equal to or higher than the crystallization temperature of the sulfide glass to synthesize a glass-ceramic having peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418Å. [Example]

[0025] Example 1 A precursor mixture containing 12.9789 g of LiS (Lorad Chemical Corporation), 26.9636 g of P2S5 (Sigma-Aldrich Co.), 1.4033 g of LiBr (Sigma-Aldrich Co.), and 8.6542 g of LiI (Sigma-Aldrich Co.) was added to a 500 ml zirconia milling jar containing zirconia milling media and a compatible solvent (e.g., xylene or heptane). The mixture was milled in a Retsch PM 100 planetary mill at 400 RPM for 12 hours. The material was collected, dried at 70 °C, and then heated to 210 °C in an inert (argon, nitrogen, or vacuum) environment. This procedure synthesized the desired novel phase. The resulting powder can be used for the positive electrode active layer, solid electrolyte layer, and / or negative electrode active layer.

[0026] Example 2 To a 500 ml zirconia milling jar containing zirconia milling media and xylene was added precursors containing 13.0188 g of LiS (Lorad Chemical Corporation), 27.0465 g of P2S5 (Sigma-Aldrich Co.), and 10.8510 g of LiI (Sigma-Aldrich Co.). The mixture was milled in a Retsch PM 100 planetary mill at 400 RPM for 12 hours. The material was recovered, dried at 70°C, and then heated to 210°C under an argon atmosphere. This procedure synthesized a composite containing the desired novel phase and an additional electrolyte phase.

[0027] Example 3 To a 500 ml zirconia milling jar containing zirconia milling media and xylene was added a precursor mixture containing 14.0726 g of LiS (Lorad Chemical Corporation), 29.2358 g of P2S5 (Sigma-Aldrich Co), and 7.6079 g of LiBr (Sigma-Aldrich Co). The mixture was milled in a Retsch PM 100 planetary mill at 400 RPM for 12 hours. The material was recovered, dried at 70°C, and then heated to 205°C under an argon atmosphere. This procedure did not result in the synthesis of the desired phase; instead, a composite containing the less desirable electrolyte phase and unreacted precursor material was obtained.

[0028] The sulfide-based solid electrolyte material obtained in Example 1 contains Li, T, X, and A. In X-ray diffraction (XRD) measurement using Cu-Kα(1,2)=1.5418Å, it has peaks at 2θ=14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50°, which identify novel crystalline phases of the solid electrolyte. T contains at least one of P, As, Si, Ge, Al, Sb, W, and B; A contains at least one of S or Se; and X is composed of F, Cl, Br, I, and / or N. The general chemical composition is Li. 1-a-b-c-d P a T b A c X dwherein a, b, c, and d can be within the ranges of 0≦a≦0.150, 0≦b≦0.176, 0.364≦c≦0.603, 0.019≦d≦0.080, or in another embodiment, can be within the ranges of 0≦a≦0.142, 0≦b≦0.165, 0.365≦c≦0.584, 0.022≦d≦0.076, or in yet another embodiment, can be within the ranges of 0≦a≦0.133, 0≦b≦0.154, 0.374≦c≦0.564, 0.026≦d≦0.059. The composition may be a mixed phase material with other crystalline phases identifiable by XRD peaks at 20.2°±0.50° and 23.6°±0.50° 2θ, and / or XRD peaks at 21.0°±0.50° and 28.0°±0.50° 2θ, and / or XRD peaks at 17.5°±0.50° and 18.2°±0.50°, and / or XRD peaks at 17.8°±0.50° and 21.8°±0.50°. The composition may include one or more lithium halide-related crystalline phases. The solid electrolyte material may include at least one of a glass-ceramic phase, a crystalline phase, and a mixed phase.

[0029] An exemplary solid electrolyte material includes Li, T, X, and A, where T is at least one element selected from the group consisting of P, As, Si, Ge, Al, Sb, W, and B, X is at least one element selected from the group consisting of F, Cl, Br, I, and N, and A is at least one element of S or Se, and the solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å.

[0030] In another embodiment, the solid electrolyte material has the formula Li 1-a-b-c-d P a T b A c X d (0≦a≦0.150, 0≦b≦0.176, 0.364≦c≦0.603, and 0.019≦d≦0.080).

[0031] In yet another embodiment, the solid electrolyte material has the formula Li1-a-b-c-d P a T b A c X d where a=0.130, b=0, c=0.478, d=0.043, A=S, and X is Br and I in a molar ratio of 1:4.

[0032] In yet another embodiment, the solid electrolyte material has the formula Li 1-a-b-c-d P a T b A c X d where a=0.130, b=0, c=0.478, d=0.043, A=S, and X is Br and I in a molar ratio of 1:4.

[0033] In another embodiment, the solid electrolyte material has the formula Li 1-a-b-c-d P a T b A c X d and the mixed phase may contain crystalline phases having peaks at 20.2°±0.50° and 23.6°±0.50°, and / or 21.0°±0.50° and 28.0°±0.50°, and / or 17.5°±0.50° and 18.2°±0.50°, and / or 17.8°±0.50° and 21.8°±0.50° in an X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å.

[0034] In another embodiment, the solid electrolyte material has the formula Li 1-a-b-c-d P a T b A c X d and the ratio of the peak intensity at 20.4°±0.50° to the peak intensity at 21.0°±0.50° is 1 or more.

[0035] An exemplary subset of compositions is Li where the index b=0. 1-a-b-c-d P a T b A c X dThe composition can be within the ranges of 0.111≦a≦0.150, b=0, 0.444≦c≦0.513, 0.024≦d≦0.069, or in another embodiment, 0.118≦a≦0.142, b=0, 0.452≦c≦0.501, 0.028≦d≦0.066, or in yet another embodiment, 0.128≦a≦0.133, b=0, 0.470≦c≦0.489, 0.033≦d≦0.051.

[0036] One exemplary composition is Li 1-a-b-c-d P a T b A c X d where a=0.130, b=0, c=0.478, d=0.043, A=S, and X is Br and I in a molar ratio of 1:4. Such compositions, after heat treatment, yield the crystalline phase of the present disclosure. The structure of this crystalline phase is sufficiently conductive to exhibit high ionic conductivity, and the presence of a halogen can aid in the formation of a stable, low-resistance interface with lithium metal and high-voltage positive electrode active materials.

[0037] Figure 3 is a plot of an X-ray diffraction measurement of a solid electrolyte composition produced by the process shown in Figure 2 according to Example 1. The X-ray diffraction (XRD) measurement shows dominant new peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50°, indicative of a previously unknown crystalline phase, using Cu-Kα(1,2)=1.5418 Å. Other compositions may be mixed phase materials with other crystalline phases characterized by XRD peaks at 20.2°±0.50° and 23.6°±0.50° 2θ, and / or peaks at 21.0°±0.50° and 28.0°±0.50° 2θ, and / or peaks at 17.5°±0.50° and 18.2°±0.50°, and / or peaks at 17.8°±0.50° and 21.8°±0.50°, and / or peaks associated with one or more lithium halides.

[0038] One illustrative embodiment is a lithium solid-state battery including: a positive electrode active material layer containing a positive electrode active material; a negative electrode active material layer containing a negative electrode active material; and 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 Li, T, X, and A, where T is at least one element selected from the group consisting of P, As, Si, Ge, Al, Sb, W, and B; X is at least one element selected from the group consisting of F, Cl, Br, I, and N; and A is at least one of S and Se, and the solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement with Cu-Kα(1,2)=1.5418 Å.

[0039] Measured examples of the compositions described herein provide conductivities of greater than approximately 0.4 mS / cm or 0.5 mS / cm at room temperature for pure and mixed phase electrolyte materials in room temperature compressed pellets. Higher conductivities may be achieved by varying the stoichiometry and / or by high temperature compression or other processing methods and conditions.

[0040] The features described above and in the following claims can be combined in various ways without departing from their scope. It should be noted, therefore, that the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not limiting. The above-described embodiments should be considered as examples of the invention rather than as limiting the scope of the invention. In addition to the above-described embodiments of the invention, other embodiments of the invention will be apparent from a review of the detailed description and accompanying drawings. Accordingly, many combinations, permutations, modifications, and improvements of the foregoing embodiments of the invention not expressly set forth herein are also within the scope of the invention. The following claims are intended to cover the general and specific features described herein, as well as any statement of the scope of the present methods and systems that may be said to fall therebetween as a matter of language. Some of the embodiments of the invention related to the present invention are shown below. [Embodiment 1] A solid electrolyte material containing Li, T, X and A, T is at least one element selected from the group consisting of P, As, Si, Ge, Al, Sb, W, and B; X is at least one element selected from the group consisting of F, Cl, Br, I, and N; and A is at least one of S and Se; The solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å. [Embodiment 2] The material has the formula Li 1-a-b-c-d P a T b A c X d 2. The solid electrolyte material of embodiment 1, having a structure in which 0≦a≦0.150, 0≦b≦0.176, 0.364≦c≦0.603, and 0.019≦d≦0.080. [Embodiment 3] 3. The solid electrolyte material of embodiment 2, wherein a=0.130, b=0, c=0.478, d=0.043, A=S, and X is Br and I in a molar ratio of 1:4. [Embodiment 4] The solid electrolyte material according to claim 1 , further comprising at least one of a glass ceramic phase, a crystalline phase, and a mixed phase. [Embodiment 5] 2. The solid electrolyte material of embodiment 1, wherein the mixed phase comprises a crystalline phase comprising peaks at 20.2°±0.50° and 23.6°±0.50°, and / or 21.0°±0.50° and 28°±0.50°, and / or 17.5°±0.50° and 18.2°±0.50°, and / or 17.8°±0.50° and 21.8°±0.50° in an X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å. [Embodiment 6] 6. The solid electrolyte material of embodiment 5, wherein the ratio of the peak intensity at 20.4°±0.50° to the peak at 21.0°±0.50° is 1 or greater. [Embodiment 7] a positive electrode active material layer containing a positive electrode active material; a negative electrode active material layer containing a negative electrode active material; and 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 solid electrolyte material containing Li, T, X, and A, wherein T is at least one element selected from the group consisting of P, As, Si, Ge, Al, Sb, W, and B; X is at least one element selected from the group consisting of F, Cl, Br, I, and N; and A is at least one of S and Se, and the solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å. [Embodiment 8] 1. A method for producing a sulfide solid electrolyte material comprising a glass ceramic containing Li, T, X, and A, wherein T is at least one element selected from the group consisting of P, As, Si, Ge, Al, Sb, W, and B, X is at least one element selected from the group consisting of F, Cl, Br, I, and N, and A is at least one element of S or Se, the method comprising: (a) Element A or compound Li 2 A, element T or a sulfide of T, and the compound LiX or Li 3 mixing and milling a raw material composition comprising N to form the mixture into an amorphous sulfide glass under X-ray diffraction; and (b) Heating the sulfide glass at a heat treatment temperature equal to or higher than the crystallization temperature of the sulfide glass to synthesize a glass ceramic having peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418Å.

Claims

1. A solid electrolyte material comprising Li, T, X, and A, T is P, X is at least one element selected from the group consisting of Br and I, and A is S; The solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å.

2. The material has the formula Li １－ａ－ｂ－ｃ－ｄ P ａ T ｂ A ｃ X ｄ 2. The solid electrolyte material of claim 1, wherein 0≦a≦0.150, 0≦b≦0.176, 0.364≦c≦0.603, and 0.019≦d≦0.

080.

3. 3. The solid electrolyte material according to claim 2, wherein a=0.130, b=0, c=0.478, d=0.043, A=S, and X is Br and I in a molar ratio of 1:

4.

4. The solid electrolyte material of claim 1 , further comprising at least one of a glass-ceramic phase, a crystalline phase, and a mixed phase.

5. 2. The solid electrolyte material according to claim 1, wherein the mixed phase comprises a crystalline phase having peaks at 20.2°±0.50° and 23.6°±0.50°, and / or 21.0°±0.50° and 28°±0.50°, and / or 17.5°±0.50° and 18.2°±0.50°, and / or 17.8°±0.50° and 21.8°±0.50° in X-ray diffraction measurement using Cu—Kα(1,2)=1.5418 Å.

6. The solid electrolyte material according to claim 5, wherein the ratio of the peak intensity at 20.4°±0.50° to the peak intensity at 21.0°±0.50° is 1 or more.

7. a negative electrode active material layer containing a positive electrode active material; a negative electrode active material layer containing a negative electrode active material; and 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 solid electrolyte material containing Li, T, X, and A, wherein T is P, X is at least one element selected from the group consisting of Br and I, and A is S, and the solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å.

8. A method for producing a sulfide solid electrolyte material comprising a glass ceramic containing Li, T, X, and A, wherein T is P, X is at least one element selected from the group consisting of Br and I, and A is S, the method comprising: (a) Element A or compound Li ２ A, element T or a sulfide of T, and the compound LiX or Li ３ mixing and milling a raw material composition containing N to form the mixture into an amorphous sulfide glass under X-ray diffraction; and (b) heating the sulfide glass at a heat treatment temperature equal to or higher than the crystallization temperature of the sulfide glass to synthesize a glass-ceramic having peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement using Cu-Kα(1,2)=1.5418 Å.

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