JP2017199631A - Sulfide solid electrolyte, electrode mixture material, and lithium ion battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sulfide solid electrolyte which exhibits an argyrodite structure regardless of particular manufacturing condition.SOLUTION: A sulfide solid electrolyte comprises lithium, phosphorus, sulfur and halogen. The sulfide solid electrolyte has diffraction peaks at least, at 2θ=15.2±0.5 deg and 2θ=17.6±0.5 deg in powder X-ray diffraction (CuKα: λ=1.5418 Å), and satisfies the following expression (1): 0.6≤S/S≤1.0 (1) (where Sis an area of the diffraction peak at 2θ=15.2±0.5 deg, and Sis an area of the diffraction peak at 2θ=17.6±0.5 deg).SELECTED DRAWING: None

Description

  The present invention relates to a sulfide solid electrolyte, an electrode mixture, and a lithium ion battery.

  With the recent development of mobile communication and information electronic equipment, demand for high-capacity and lightweight lithium ion secondary batteries tends to increase. Most electrolytes exhibiting high lithium ion conductivity at room temperature are liquids, and many of the commercially available lithium ion secondary batteries use organic electrolytes. In the lithium ion secondary battery using this organic electrolyte, there is a risk of leakage, ignition and explosion, and a battery with higher safety is desired. In response to the above demand, an all-solid battery using a sulfide solid electrolyte has been developed.

There are various crystal structures of the sulfide solid electrolyte. Among them, the Argyrodite structure is known to have high stability and relatively high ionic conductivity.
For example, Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2 disclose sulfide solid electrolytes having an aldilodite structure. However, after performing a mechanical milling reaction using a planetary ball mill, heat treatment at a high temperature of 550 ° C., and the like, the aldilodite crystal structure could not be fully expressed unless the production conditions were special.

JP 2013-211171 A

Angew. chem Vol. 47 (2008), no. 4, P. 755-758 Phys. Status. Solidi Vol. 208 (2011), no. 8, P.I. 1804-1807

  It is an object of the present invention to provide a sulfide solid electrolyte that exhibits an aldilodite structure regardless of special production conditions.

According to the present invention, the following sulfide solid electrolyte and the like are provided.
1. Lithium, phosphorus, sulfur and halogen are contained, and in powder X-ray diffraction (CuKα: λ = 1.5418４), diffraction peaks are at least 2θ = 15.2 ± 0.5 deg and 2θ = 17.6 ± 0.5 deg. A sulfide solid electrolyte having and satisfying the following formula (1).
0.6 ≦ S _a / S _b ≦ 1.0 (1)
(In the formula, S _a is the area of the diffraction peak at 2θ = 15.2 ± 0.5 deg, and S _b is the area of the diffraction peak at 2θ = 17.6 ± 0.5 deg.)
2. The lithium element ratio (M _Li ), the phosphorus element ratio (M _P ), and the sulfur element ratio (M _S ) with respect to the total of lithium, phosphorus and sulfur satisfy the following formulas (2) to (4): The sulfide solid electrolyte described.
0.350 ≦ M _Li ≦ 0.500 (2)
_{0.010 ≦ M P ≦ 0.150 ··· (} 3)
0.400 ≦ M _S ≦ 0.550 (4)
_{(Wherein, M Li} is the element ratio of lithium, _{M P} is the element ratio of phosphorus, the _{M S} represents an element ratio of sulfur.)
3. 3. The sulfide solid electrolyte according to 1 or 2, which has a diffraction peak at 2θ = 25.0 ± 0.5 deg in powder X-ray diffraction (CuKα: λ = 1.5418Å).
The electrode compound material containing the sulfide solid electrolyte in any one of 4.1-3, and an active material.
5. A lithium ion battery comprising at least one of the sulfide solid electrolyte according to any one of 5.1 to 3 and the electrode mixture according to 4.
The electrode compound material manufactured with the sulfide solid electrolyte in any one of 6.1-3.
7.1 A lithium ion battery manufactured by at least one of the sulfide solid electrolyte according to any one of 1 to 3 and the electrode mixture according to 4, and the electrode mixture according to 6.

  According to the present invention, a sulfide solid electrolyte containing an aldilodite structure can be manufactured more easily than the conventional method.

2 is a differential scanning calorimetry (DSC) measurement result of the sulfide solid electrolyte obtained in Example 1. 2 is an X-ray diffraction (XRD) pattern of the sulfide solid electrolyte obtained in Example 1. FIG. 3 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Example 1. 4 is a DSC measurement result of the sulfide solid electrolyte obtained in Example 3. 3 is an XRD pattern of a sulfide solid electrolyte obtained in Example 3. 4 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Example 3. 4 is a DSC measurement result of the sulfide solid electrolyte obtained in Example 5. 7 is an XRD pattern of the sulfide solid electrolyte obtained in Example 5. 7 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Example 5. 4 is a DSC measurement result of the sulfide solid electrolyte obtained in Example 7. 7 is an XRD pattern of the sulfide solid electrolyte obtained in Example 7. 7 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Example 7. 4 is a DSC measurement result of the sulfide solid electrolyte obtained in Example 9. 7 is an XRD pattern of the sulfide solid electrolyte obtained in Example 9. It is a XRD pattern after heat processing of the sulfide solid electrolyte obtained in Example 9. 4 is a DSC measurement result of the sulfide solid electrolyte obtained in Example 11. 4 is an XRD pattern of the sulfide solid electrolyte obtained in Example 11. 6 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Example 11. FIG. 3 is a DSC measurement result of the sulfide solid electrolyte obtained in Comparative Example 1. 3 is an XRD pattern of a sulfide solid electrolyte obtained in Comparative Example 1. 4 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Comparative Example 1. 4 is a DSC measurement result of the sulfide solid electrolyte obtained in Comparative Example 3. 4 is an XRD pattern of a sulfide solid electrolyte obtained in Comparative Example 3. 4 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Comparative Example 3. 6 is a DSC measurement result of the sulfide solid electrolyte obtained in Comparative Example 5. 7 is an XRD pattern of a sulfide solid electrolyte obtained in Comparative Example 5. 6 is an XRD pattern after heat treatment of the sulfide solid electrolyte obtained in Comparative Example 5.

The sulfide solid electrolyte of the present invention contains lithium, phosphorus, sulfur and halogen (F, I, Br, Cl, At, etc.), and at least 2θ = 15 in powder X-ray diffraction (CuKα: λ = 1.5418４). It has diffraction peaks at 2 ± 0.5 deg and 2θ = 17.6 ± 0.5 deg. And it is characterized by satisfy | filling following formula (1).
0.6 ≦ S _a / S _b ≦ 1.0 (1)
(In the formula, S _a is the area of the diffraction peak at 2θ = 15.2 ± 0.5 deg, and S _b is the area of the diffraction peak at 2θ = 17.6 ± 0.5 deg.)
In the present application, the “sulfide solid electrolyte” is a substance that contains sulfur and is solid at 25 ° C. under 1 atm and has lithium ion conductivity. Further, for example, a diffraction peak at 2θ = 15.2 ± 0.5 deg has a peak top in the range of 2θ = 15.2 ± 0.5 deg, and when there are a plurality of corresponding peaks, the peak area is maximum. Means a peak.

The diffraction peaks at 2θ = 15.2 ± 0.5 and 17.6 ± 0.5 deg in the powder X-ray diffraction are peaks derived from the aldilodite crystal structure. That is, the sulfide solid electrolyte of the present invention has an aldilodite crystal structure. Examples of the aldilodite crystal structure include crystal structures disclosed in JP-T 2010-540396, JP-A 2011-096630, JP-A 2013-211171, and the like. Specific examples include Li ₆ PS ₅ X, Li _7-x PS _6-x X _x (X = Cl, Br, I, x = 0.0 to 1.8).
In the X-ray diffraction measurement, the diffraction peak of the aldilodite crystal structure also appears at 2θ = 25.0 ± 0.5 deg, 47.0 ± 0.5 deg, or 52.0 ± 0.5 deg, for example. The sulfide solid electrolyte of the present invention may have these peaks.

The above formula (1) means that the intensity ratio of the peak at 2θ = 15.2 ± 0.5 deg to the peak at 2θ = 17.6 ± 0.5 deg is 0.6 or more and 1.0 or less. To do.
The intensity ratio (S _a / S _b ) is preferably from 0.65 to 0.99, more preferably from 0.7 to 0.99, and particularly preferably from 0.74 to 0.99.
In addition, about the measurement of a peak area, an analysis method, etc., it shall be based on the method as described in the Example mentioned later.

The diffraction peak of 2θ = 15.2 ± 0.5 deg described above preferably exists in the range of 2θ = 15.2 ± 0.3 deg, and preferably exists in the range of 2θ = 15.2 ± 0.2 deg. More preferably. Similarly, the diffraction peak of 2θ = 17.6 ± 0.5 deg is preferably in the range of 2θ = 17.6 ± 0.3 deg, and preferably in the range of 2θ = 17.6 ± 0.2 deg. Is more preferable. Further, when a peak exists at any of 2θ = 25 ± 0.5 deg, 47 ± 0.5 deg, 52 ± 0.5 deg, 2θ = 25 ± 0.3 deg, 47 ± 0. A peak is preferably present in the range of 3 deg and 52 ± 0.3 deg, and more preferably in the range of 2θ = 25 ± 0.2 deg, 47 ± 0.2 deg and 52 ± 0.2 deg.

The sulfide solid electrolyte of the present invention does not have a diffraction peak (a typical lithium sulfide-derived peak) at 2θ = 26.8 ± 0.5 deg in powder X-ray diffraction (CuKα: λ = 1.5418Å). Is preferred.
Further, it is preferable that 2θ = 52.9 ± 0.5 deg does not have a diffraction peak (other peaks derived from lithium sulfide).

In the sulfide solid electrolyte of the present invention, the lithium element ratio (M _Li ), the phosphorus element ratio (M _P ), and the sulfur element ratio (M _S ) with respect to the total of lithium, phosphorus, and sulfur are the following formulas (2) to (2): It is preferable to satisfy (4).
0.350 ≦ M _Li ≦ 0.500 (2)
_{0.010 ≦ M P ≦ 0.150 ··· (} 3)
0.400 ≦ M _S ≦ 0.550 (4)
_{(Wherein, M Li} is the element ratio of lithium, _{M P} is the element ratio of phosphorus, the _{M S} represents an element ratio of sulfur.)
More preferably, the following formula is satisfied.
0.375 ≦ M _Li ≦ 0.495
0.020 ≦ M _P ≦ 0.130
0.450 ≦ M _S ≦ 0.540
Most preferably, the following formula is satisfied.
0.400 ≦ M _Li ≦ 0.490
0.040 ≦ M _P ≦ 0.110
0.452 ≦ M _S ≦ 0.530

Moreover, it is preferable to make the element ratio of sulfur contained in the sulfide solid electrolyte relatively high. This makes it easy to obtain a sulfide solid electrolyte having an aldilodite crystal structure without heat treatment at a high temperature. Here, relatively increasing the elemental ratio of sulfur means the following. The element ratios of lithium element, sulfur and phosphorus contained in the entire raw material of the sulfide solid electrolyte are x, y and z (x + y + z = 1), respectively, and these elements are a mixture of Li ₂ S and P ₂ S ₅ [aLi ₂ S + bP. ₂ S ₅ , (a + b = 1)], the element ratios x, y, and z are expressed by the following formulas (a) to (c).
x = 2a (a)
y = a + 5b (b)
z = 2b (c)
In the present application, when the sulfur element ratio y is higher than a + 5b (y> a + 5b), the sulfur element ratio is relatively high.

The sulfide solid electrolyte of the present invention contains a halogen. The molar ratio of halogen (X) (M _X / (M _Li + _MP + M _S + M _X )) is preferably 0.001 to 0.400, more preferably 0.005 to 0.300. In particular, it is preferably 0.015 to 0.200.

  In order to adjust the elemental composition of the sulfide solid electrolyte, for example, when using lithium sulfide, phosphorus sulfide and lithium halide as raw materials, sulfur such as elemental sulfur, organic / inorganic polysulfides, sulfur nitride, etc. A compound is used as a raw material, and the element ratio of sulfur element is relatively increased. In particular, it is preferable to use elemental sulfur as a raw material.

The sulfide solid electrolyte of the present invention can be produced by mixing a raw material containing the above-mentioned optional element with lithium, phosphorus, sulfur and halogen, if desired, and performing a synthesis treatment.
As raw materials, Li ₂ S (lithium sulfide), phosphorus sulfide, SiS ₂ (silicon sulfide), Li ₄ SiO ₄ (lithium orthosilicate), Al ₂ S ₃ (aluminum sulfide), simple phosphorus (P), simple sulfur (S), silicon (Si), GeS ₂ (germanium sulfide), SnS ₂ (tin sulfide), B ₂ S ₃ (diboron trisulfide), Li ₃ PO ₄ (lithium phosphate), Li ₄ GeO ₄ (germane) Acid lithium), Li ₂ SnO ₃ (lithium stannate), LiBO ₂ (lithium metaborate), LiAlO ₃ (lithium aluminate), LiF (lithium fluoride), LiCl (lithium chloride), LiI (lithium iodide), LiBr (lithium bromide) or the like can be used.

Hereinafter, an example using lithium sulfide, phosphorus sulfide, elemental sulfur and lithium halide as raw materials will be described.
Lithium sulfide used as a raw material is not particularly limited, and for example, industrially available ones can be used, and Japanese Patent Application Laid-Open Nos. 7-3301212, 9-283156, 2010-163356, Lithium sulfide that can be produced by the method disclosed in JP 2011-084438 A can be used.
In JP-A-2010-163356, lithium hydroxide and hydrogen sulfide are reacted at 70 ° C. to 300 ° C. in a hydrocarbon organic solvent to produce lithium hydrosulfide, and this reaction solution is then desulfurized. Lithium sulfide is synthesized by hydrogenation. Moreover, in the said Unexamined-Japanese-Patent No. 2011-084438, lithium hydroxide and hydrogen sulfide are made to react at 10 to 100 degreeC in a water solvent, lithium lithium sulfide is produced | generated, and this reaction liquid is then dehydrosulfurized. To synthesize lithium sulfide.

  In the method for producing lithium sulfide described in JP-A-7-330312 and JP-A-9-283156, the obtained lithium sulfide contains a lithium salt of sulfur oxide and the like, and thus it is preferably purified. On the other hand, in the method for producing lithium sulfide described in JP 2010-163356 A, the obtained lithium sulfide can be used as it is without purification because it contains a very small amount of lithium oxide lithium salt or the like.

When purifying lithium sulfide, a preferable purification method includes, for example, a purification method disclosed in International Publication WO2005 / 40039, and the obtained lithium sulfide is washed with an organic solvent at a temperature of 100 ° C. or higher. To purify.
Further, the purity of the lithium sulfide is preferably 90.0% or more, more preferably 98.0% or more, more preferably 99.0% or more, and 99.9% or more. Most preferred.

There is no limitation in particular as phosphorus sulfide, For example, what was manufactured and sold industrially may be used. Specific examples include P ₂ S ₃ (phosphorus trisulfide) and P ₂ S ₅ (phosphorus pentasulfide). These phosphorus sulfides can be used alone or in combination of two or more.
The purity of phosphorus sulfide is preferably 90.0% or more, more preferably 98.0% or more, more preferably 99.0% or more, and 99.9% or more. Most preferred.

There is no limitation in particular as simple element sulfur, For example, what is manufactured and sold industrially may be used.
Further, the elemental sulfur preferably has a purity of 90.0% or more, more preferably 98.0% or more, more preferably 99.0% or more, and 99.9% or more. Most preferred.

There is no limitation in particular as lithium halide, For example, what is manufactured and sold industrially may be used. Examples thereof include LiF, LiCl, LiI, and LiBr. Lithium halides can be used alone or in combination of two or more.
Further, the purity of the lithium halide is preferably 90.0% or more, more preferably 98.0% or more, more preferably 99.0% or more, and 99.9% or more. Most preferably it is.

The ratio of lithium sulfide and phosphorus sulfide in the raw material is preferably 98 to 60 mol%: 2 to 40 mol%, preferably 95 to 65 mol%: 5 to 35 mol%, more preferably 95 to 77 mol%: 5 to 23 mol%, and 93 to 78 mol%: 7-22 mol% is most preferable.
The amount of elemental sulfur added is, for example, when lithium sulfide, phosphorus sulfide, and elemental sulfur are used as raw materials, lithium sulfide and phosphorus sulfide (Li ₂ S + P ₂ S ₅ ), and the total amount of elemental sulfur is 100 mol%. 5 mol% to 80 mol% is preferable, 10 mol% to 70 mol% is preferable, and 15 mol% to 65 mol% is more preferable.
The amount of lithium halide added is, for example, when lithium sulfide, phosphorus sulfide, and red phosphorus are used as raw materials, and the total amount of lithium sulfide, phosphorus sulfide (Li ₂ S + P ₂ S ₅ ), red phosphorus, and lithium halide is 100 mol. %, Preferably 0.1 mol% to 50 mol%, more preferably 1 mol% to 40 mol%, and particularly preferably 3 mol% to 30 mol%.

As a method for producing a sulfide solid electrolyte from the above raw materials, a MM (mechanical milling) method, a melt quenching method, a method of bringing a raw material into contact in a hydrocarbon solvent (WO2009 / 047977), and a raw material in a hydrocarbon solvent. Either a method of alternately performing the contacting means and the pulverizing / synthesizing means (Japanese Patent Laid-Open No. 2010-140893) or a method of performing the pulverizing / synthesizing step after the step of contacting the raw materials in the solvent (PCT / JP2012 / 005992) may be used.

  The solvent may be a polar solvent or a nonpolar solvent. Nonpolar solvents include hydrocarbon solvents. Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents, and mixing in an aromatic hydrocarbon solvent is preferable. As the aromatic hydrocarbon solvent, alkylbenzene is preferable. As the alkylbenzene, toluene is preferable.

Although the temperature at the time of manufacture does not have limitation in particular, For example, they are 0 degreeC or more and 150 degrees C or less, 5 degreeC or more and 140 degrees C or less. When using a solvent, the boiling point of the solvent or less is preferred.
The production time is not particularly limited, but is, for example, 1 hour to 72 hours, 2 hours to 48 hours.

The sulfide solid electrolyte of the present invention may be heat-treated if necessary. Due to the heat treatment, crystallization may further progress, or a crystal structure other than the aldilodite crystal structure may appear (for example, Li ₃ PS ₄ crystal structure). The temperature of the heat treatment can be determined with reference to the peak position observed by differential scanning calorimetry (DSC) measurement. For example, 100-350 degreeC is preferable. The heating time is preferably 0.005 minutes or more and 10 hours or less. More preferably, it is 0.005 minutes or more and 4 hours or less, and particularly preferably 1 minute or more and 3 hours or less.
There is no specific specification for the temperature raising method. The temperature may be raised slowly to a predetermined temperature or heated rapidly.
Heating is preferably performed in an environment with a dew point of −40 ° C. or lower, more preferably in an environment with a dew point of −60 ° C. or lower. The atmospheric pressure during heating may be a normal pressure or a reduced pressure. The atmosphere may be in the air or an inert atmosphere.

  The sulfide solid electrolyte of the present invention can be used for a solid electrolyte layer such as a lithium ion secondary battery, a positive electrode, a negative electrode, and the like.

[Electrode compound]
The electrode mixture of the present invention includes the above-described sulfide solid electrolyte of the present invention and an active material. Or it manufactures with the sulfide solid electrolyte of this invention. When a negative electrode active material is used as the active material, a negative electrode mixture is obtained. On the other hand, when a positive electrode active material is used, it becomes a positive electrode mixture.

-Negative electrode compound material A negative electrode compound material is obtained by mix | blending a negative electrode active material with the sulfide solid electrolyte of this invention.
As the negative electrode active material, for example, a carbon material, a metal material, or the like can be used. Among these, a complex composed of two or more kinds can also be used. Moreover, a negative electrode active material developed in the future can also be used.
Moreover, it is preferable that the negative electrode active material has electronic conductivity.
Examples of carbon materials include graphite (eg, artificial graphite), graphite carbon fiber, resin-fired carbon, pyrolytic vapor-grown carbon, coke, mesocarbon microbeads (MCMB), furfuryl alcohol resin-fired carbon, polyacene, pitch-based carbon. Examples thereof include fibers, vapor-grown carbon fibers, natural graphite, and non-graphitizable carbon.
Examples of the metal material include simple metals, alloys, and metal compounds. Examples of the metal simple substance include metal silicon, metal tin, metal lithium, metal indium, and metal aluminum. Examples of the alloy include an alloy containing at least one of silicon, tin, lithium, indium, and aluminum. Examples of the metal compound include metal oxides. Examples of the metal oxide include silicon oxide, tin oxide, and aluminum oxide.

The mixing ratio of the negative electrode active material and the solid electrolyte is preferably negative electrode active material: solid electrolyte = 95 wt%: 5 wt% to 5 wt%: 95 wt%, 90 wt%: 10 wt% to 10 wt%: 90 wt%. % Is more preferable, and 85% by weight: 15% by weight to 15% by weight: 85% by weight is more preferable.
When there is too little content of the negative electrode active material in a negative electrode compound material, an electrical capacity will become small. In addition, when the negative electrode active material has electronic conductivity and does not contain a conductive aid or contains only a small amount of a conductive aid, the electronic conductivity (electron conduction path) in the negative electrode is reduced, and the rate It is considered that there is a possibility that the characteristics may be lowered, or the utilization rate of the negative electrode active material may be reduced, and the electric capacity may be reduced. On the other hand, if the content of the negative electrode active material in the negative electrode mixture is too large, the ion conductivity (ion conduction path) in the negative electrode is lowered, the rate characteristics may be lowered, the utilization rate of the negative electrode active material is lowered, and We think that capacity may decrease.

The negative electrode mixture can further contain a conductive additive.
When the negative electrode active material has low electronic conductivity, it is preferable to add a conductive additive. The conductive auxiliary agent only needs to have conductivity, and its electronic conductivity is preferably 1 × 10 ³ S / cm or more, more preferably 1 × 10 ⁵ S / cm or more.
Specific examples of conductive aids are preferably carbon materials, nickel, copper, aluminum, indium, silver, cobalt, magnesium, lithium, chromium, gold, ruthenium, platinum, beryllium, iridium, molybdenum, niobium, osnium, rhodium, A substance containing at least one element selected from the group consisting of tungsten and zinc, and more preferably a carbon simple substance having a high conductivity, or a carbon material other than simple carbon; nickel, copper, silver, cobalt, magnesium, lithium, ruthenium , Gold, platinum, niobium, osnium or rhodium, simple metals, mixtures or compounds.
Specific examples of carbon materials include carbon blacks such as ketjen black, acetylene black, denka black, thermal black, and channel black; graphite, carbon fiber, activated carbon, and the like. These may be used alone or in combination of two or more. Is possible. Among these, acetylene black, denka black, and ketjen black having high electron conductivity are preferable.

  The content of the conductive additive in the composite material when the negative electrode composite contains the conductive additive is preferably 1 to 40% by mass, more preferably 2 to 20% by mass. If the content of the conductive additive is too small, the electron conductivity of the negative electrode may be reduced to lower the rate characteristics, and the utilization rate of the negative electrode active material may be reduced, resulting in a decrease in electric capacity. On the other hand, when there is too much content of a conductive support agent, the quantity of a negative electrode active material and / or the quantity of a solid electrolyte will decrease. It is estimated that the electric capacity decreases when the amount of the negative electrode active material decreases. Further, when the amount of the solid electrolyte is reduced, it is considered that the ion conductivity of the negative electrode is lowered, the rate characteristics may be lowered, the utilization rate of the negative electrode active material is lowered, and the electric capacity may be lowered.

In order to tightly bind the negative electrode active material and the solid electrolyte to each other, a binder may be further included.
Binders include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), fluorine-containing resins such as fluorine rubber, thermoplastic resins such as polypropylene and polyethylene, ethylene-propylene-diene rubber (EPDM), and sulfonation. EPDM, natural butyl rubber (NBR) or the like can be used alone or as a mixture of two or more. In addition, an aqueous dispersion of cellulose or styrene butadiene rubber (SBR), which is an aqueous binder, can also be used.

The negative electrode mixture can be produced by mixing a solid electrolyte, a negative electrode active material, and an optional conductive additive and / or binder.
The mixing method is not particularly limited, but, for example, dry mixing using a mortar, ball mill, bead mill, jet mill, planetary ball mill, vibrating ball mill, sand mill, cutter mill; and mortar after dispersing the raw material in an organic solvent , Ball mill, bead mill, planetary ball mill, vibrating ball mill, sand mill, and wet mix, and then wet mixing to remove the solvent can be applied. Among these, wet mixing is preferable in order not to destroy the negative electrode active material particles.

-Positive electrode mixture A positive electrode mixture is obtained by mix | blending a positive electrode active material with the solid electrolyte of this invention.
The positive electrode active material is a material capable of inserting and removing lithium ions, and those known as positive electrode active materials in the battery field can be used. Moreover, the positive electrode active material developed in the future can also be used.

Examples of the positive electrode active material include metal oxides and sulfides. The sulfide includes a metal sulfide and a nonmetal sulfide.
The metal oxide is, for example, a transition metal oxide. Specifically, V ₂ O ₅ , V ₆ O ₁₃ , LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , Li (Ni _a Co _b Mn _c ) O ₂ (where 0 <a <1, 0 <b <1, 0 <c <1, a + b + c = 1), LiNi _1-Y Co _{Y 2} O ₂ , LiCo _1-Y Mn _{Y 2} O ₂ , LiNi _1-Y Mn _{Y 2} O ₂ (where 0 ≦ Y _{<1), Li (Ni a} Co b Mn c) O 4 (0 <a <2,0 <b <2,0 <c <2, a + b + c = 2), LiMn 2-Z Ni Z O 4, LiMn 2 _-Z Co _Z O ₄ (where 0 <Z <2), LiCoPO ₄ , LiFePO ₄ , CuO, Li (Ni _a Co _b Al _c ) O ₂ (where 0 <a <1, 0 <b < 1, 0 <c <1, a + b + c = 1) and the like.
Examples of the metal sulfide include titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), iron sulfide (FeS, FeS ₂ ), copper sulfide (CuS), and nickel sulfide (Ni ₃ S ₂ ).
Other examples of the metal oxide include bismuth oxide (Bi ₂ O ₃ ) and bismuth leadate (Bi ₂ Pb ₂ O ₅ ).
Examples of non-metal sulfides include organic disulfide compounds and carbon sulfide compounds.
In addition to the above, niobium selenide (NbSe ₃ ), metal indium, and sulfur can also be used as the positive electrode active material.

The positive electrode mixture may further contain a conductive additive.
The conductive auxiliary agent is the same as the negative electrode mixture.

  The blending ratio of the solid electrolyte and the positive electrode active material of the positive electrode mixture, the content of the conductive additive, and the method for producing the positive electrode mixture are the same as those of the negative electrode mixture described above.

[Lithium ion battery]
The lithium ion battery of the present invention includes at least one of the above-described sulfide solid electrolyte and electrode mixture of the present invention. Or it manufactures with at least 1 among the sulfide solid electrolyte of this invention, and an electrode compound material.
The configuration of the lithium ion battery is not particularly limited, but generally has a structure in which a negative electrode layer, an electrolyte layer, and a positive electrode layer are laminated in this order. Hereinafter, each layer of the lithium ion battery will be described.

(1) Negative electrode layer The negative electrode layer is preferably a layer produced from the negative electrode mixture of the present invention.
Alternatively, the negative electrode layer is preferably a layer containing the negative electrode mixture of the present invention.
The thickness of the negative electrode layer is preferably from 100 nm to 5 mm, more preferably from 1 μm to 3 mm, and even more preferably from 5 μm to 1 mm.
A negative electrode layer can be manufactured by a well-known method, for example, can be manufactured by the apply | coating method and an electrostatic method (an electrostatic spray method, an electrostatic screen method, etc.).

(2) Electrolyte layer The electrolyte layer is a layer containing a solid electrolyte or a layer manufactured from a solid electrolyte. The solid electrolyte is not particularly limited, but is preferably the sulfide solid electrolyte of the present invention.
The electrolyte layer may consist only of a solid electrolyte, and may further contain a binder. As the binder, the same binder as that for the negative electrode mixture of the present invention can be used.

The thickness of the electrolyte layer is preferably 0.001 mm or more and 1 mm or less.
The solid electrolyte of the electrolyte layer may be fused. Fusion means that a part of the solid electrolyte particles is dissolved and the dissolved part is integrated with other solid electrolyte particles. The electrolyte layer may be a solid electrolyte plate, and the plate includes a case where a part or all of the solid electrolyte particles are dissolved to form a plate.
The electrolyte layer can be manufactured by a known method, and can be manufactured by, for example, a coating method or an electrostatic method (an electrostatic spray method, an electrostatic screen method, or the like).

(3) Positive electrode layer A positive electrode layer is a layer containing a positive electrode active material, Preferably it is a layer containing the positive electrode compound material of this invention, or the layer manufactured from the positive electrode compound material of this invention.
The thickness of the positive electrode layer is preferably 0.01 mm or more and 10 mm or less.
A positive electrode layer can be manufactured by a well-known method, for example, can be manufactured by the apply | coating method and an electrostatic method (an electrostatic spray method, an electrostatic screen method, etc.).

(4) Current collector The lithium ion battery of the present invention preferably further comprises a current collector. For example, the negative electrode current collector is provided on the side of the negative electrode layer opposite to the electrolyte layer side, and the positive electrode current collector is provided on the side of the positive electrode layer opposite to the electrolyte layer side.
As the current collector, a plate or foil made of copper, magnesium, stainless steel, titanium, iron, cobalt, nickel, zinc, aluminum, germanium, indium, lithium, or an alloy thereof can be used.

The lithium ion battery of the present invention can be manufactured by bonding and joining the above-described members. As a method of joining, there are a method of laminating each member, pressurizing and pressure bonding, a method of pressing through two rolls (roll to roll), and the like.
Moreover, you may join to the joining surface through the active material which has ion conductivity, and the adhesive material which does not inhibit ion conductivity.
In joining, heat fusion may be performed as long as the crystal structure of the solid electrolyte does not change.
The lithium ion battery of the present invention can also be manufactured by sequentially forming the above-described members. It can be manufactured by a known method, for example, it can be manufactured by a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

Hereinafter, the present invention will be described in more detail with reference to examples.
The evaluation method is as follows.
(1) Ionic conductivity measurement The sulfide solid electrolyte produced in each example was filled in a tablet molding machine, and a pressure of 22 MPa was applied to obtain a molded body. Carbon was placed on both sides of the molded body as an electrode, and pressure was again applied with a tablet molding machine to prepare a molded body for measurement (diameter of about 10 mm, thickness of 0.1 to 0.2 cm). The ion conductivity of this molded body was measured by AC impedance measurement. The conductivity value was a value at 25 ° C.
In addition, in the measurement method of the ionic conductivity used in the present example, when the ionic conductivity is less than 1.0 × 10 ⁻⁶ S / cm, the ionic conductivity cannot be measured accurately, and thus cannot be measured. It was.

(2) Differential scanning calorific value (DSC) measurement It carried out in the temperature range of 50-350 degreeC by the temperature increase rate of 2 degree-C / min in dry nitrogen atmosphere. Here, since the purpose of measuring the peak is to search for the crystallization temperature, the measurement may be stopped at an arbitrary temperature before reaching 350 ° C. when the peak appears. Using a differential scanning calorimeter (Diamond DSC manufactured by Perkin Elmer), the sample was measured at about 15 mg.

(3) X-ray diffraction (XRD) measurement A circular pellet having a diameter of 10 mm and a height of 0.1 to 0.3 cm was formed from a sulfide solid electrolyte powder produced in each example to prepare a sample. This sample was measured using an airtight holder for XRD without being exposed to air. The 2θ position of the diffraction peak was determined by the centroid method using the XRD analysis program JADE.
The measurement was performed under the following conditions using a powder X-ray diffraction measurement device SmartLab manufactured by Rigaku Corporation.
Tube voltage: 45kV
Tube current: 200 mA
X-ray wavelength: Cu-Kα ray (1.5418mm)
Optical system: Parallel beam method Slit configuration: Solar slit 5 °, entrance slit 1 mm, light receiving slit 1 mm
Detector: Scintillation counter Measurement range: 2θ = 10-60 °
Step width, scan speed: 0.02 °, 1 ° / min From the measurement results, two peak areas of the argilodite structure existing at 2θ = 15.2 ± 0.5 deg and 17.6 ± 0.5 deg are analyzed, The intensity ratio was calculated. In the analysis of the peak area, an XRD analysis program JADE was used, a baseline was drawn by cubic approximation, peak fitting was performed as a Gaussian function symmetrical peak, and the area of each peak was calculated.

Production Example 1
(Production of lithium sulfide (Li ₂ S))
Under a nitrogen stream, 303.8 kg of toluene as a nonpolar solvent was added to a 500 L tank reactor, 33.8 kg of lithium hydroxide (an anhydrous product manufactured by Honjo Chemical Co., Ltd.) was added, and the mixture was stirred with a flat paddle type stirring blade 131 rpm. The temperature was raised to 108 ° C. while blowing hydrogen sulfide into the slurry at a supply rate of 10 L / hour. An azeotropic gas of water and toluene was continuously discharged from the 500 L tank reactor. This azeotropic gas was dehydrated by condensing with a condenser outside the system. During this time, the same amount of toluene as the distilled toluene was continuously supplied to keep the reaction liquid level constant.
The amount of water in the condensate gradually decreased, and water distilling was not observed 24 hours after the introduction of hydrogen sulfide. During the reaction, the solid was dispersed and stirred in toluene, and there was almost no water separated from toluene.
Subsequently, the temperature of the reactor was kept at 50 ° C. while blowing hydrogen sulfide, and the reaction was carried out for 21 hours. Further, while the hydrogen sulfide was blown in, the temperature of the reactor was kept at 70 ° C. and reacted for 10 hours. Thereafter, the temperature of the reactor was raised to 108 ° C., the hydrogen sulfide was switched to nitrogen, and the mixture was circulated at 20 L / min for 16 hours to obtain a lithium sulfide toluene slurry.
The obtained slurry was fed to a conical dryer, and after removing the supernatant toluene, it was vacuum dried at 90 ° C. for 12 hours to obtain lithium sulfide.

Example 1
Lithium sulfide (purity 98.6%), diphosphorus pentasulfide (FS SPEC, manufactured by Thermophos, purity 99.9% or more), sulfur (Sulfur 99.998% (213292)), Sigma-Aldrich, manufactured in Production Example 1 And lithium bromide (lithium bromide (anhydride), manufactured by Honjo Chemical Co., Ltd., purity 99.4% or more) were used as starting materials (hereinafter, in all Examples, the purity of each starting material) Is the same). The molar ratio of lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), sulfur (S) and lithium bromide (LiBr) (Li ₂ S: P ₂ S ₅ : S: LiBr) is 47. Each raw material was mixed so that it might become 6: 5.3: 35.2: 11.9. Specifically, 0.4011 g of lithium sulfide, 0.2128 g of diphosphorus pentasulfide, 0.2044 g of sulfur, and 0.1877 g of lithium bromide were mixed to obtain a raw material mixture.
The raw material mixture and 30 g of a zirconia ball having a diameter of 10 mm were placed in a planetary ball mill (manufactured by Fritsch: Model No. P-7) made of alumina (45 mL) and completely sealed. The inside of the pot was an argon atmosphere. Mechanical milling was performed with a planetary ball mill at a rotation speed of 370 rpm for 72 hours to obtain a sulfide solid electrolyte powder.

The differential scanning calorimetry (DSC) measurement results of the sulfide solid electrolyte obtained in Example 1 are shown in FIG. In the DSC measurement, a clear crystallization temperature was not observed, but a minute peak thought to be attributed to an unreacted component was observed around 120 ° C.
An X-ray diffraction (XRD) pattern is shown in FIG. 2θ = 26.8, 31.0, 44.6, 52.9 deg, peaks that are considered to be derived from Li ₂ S, and 2θ = 15.2, 17.6, 25.0, 29.5, Peaks thought to be derived from the aldilodite structure were observed at 31.0, 44.6, 47.3, and 51.7 deg. The peak of 2θ = 31.0,44.6deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.
Table 1 shows the molar ratio of each element and the heat treatment temperature in the raw materials of Example 1 and Examples and Comparative Examples described later. Also shows the area of the peak of 2θ = 15.2 ± 0.5deg observed by XRD _S a, the peak area _{S b} and the intensity ratio of 2 [Theta] = 17.6 ± 0.5 deg in Table 2.

Example 2
About 0.5 g of the sulfide solid electrolyte of Example 1 was heat-treated on a hot plate (manufactured by ND-1 ASONE) under a nitrogen atmosphere. Specifically, the hot plate was previously set to 135 ° C., and the sulfide solid electrolyte spread uniformly on the aluminum foil was placed on the hot plate and heated for 1 hour.
The ionic conductivity (σ) of the sulfide solid electrolyte after heat treatment was measured and found to be 1.2 × 10 ⁻⁴ S / cm.
FIG. 3 shows the XRD pattern of the sulfide solid electrolyte after the heat treatment. 2θ = 26.8, 31.0, 44.6, 52.9 deg, the peaks considered to be derived from Li ₂ S, and 2θ = 15.2, 17.7, 25.0, 29.5, Peaks thought to be derived from the aldilodite structure were observed at 31.0, 44.6, 47.2, 51.7, and 58.4 deg. The peak of 2θ = 31.0,44.6deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.

Example 3
The respective raw materials were mixed so that the molar ratio of the raw materials (Li ₂ S: P ₂ S ₅ : S: LiBr) was 54.2: 13.6: 17.0: 15.2. Specifically, 0.3428 g of lithium sulfide, 0.4092 g of diphosphorus pentasulfide, 0.0737 g of sulfur, and 0.1797 g of lithium bromide were mixed to obtain a raw material mixture. A solid electrolyte was manufactured and evaluated.
The DSC measurement result of the sulfide solid electrolyte obtained in Example 3 is shown in FIG. In the DSC measurement, a crystallization peak was observed around 170 ° C. An XRD pattern is shown in FIG.

Example 4
The sulfide solid electrolyte of Example 3 was heat-treated in the same manner as in Example 2. The heat treatment temperature was 180 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 1.6 × 10 ⁻³ S / cm.
The XRD pattern of the sulfide solid electrolyte after heat treatment is shown in FIG. 2θ = 26.8, 31.0, 44.6, 53.0 deg, the peaks considered to be derived from Li ₂ S, and 2θ = 15.2, 17.7, 25.1, 29.5, Peaks believed to be derived from the aldilodite structure were observed at 31.0, 44.6, 47.2, 51.7, and 58.5 deg. The peak of 2θ = 31.0,44.6deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.

Example 5
The respective raw materials were mixed so that the molar ratio of the raw materials (Li ₂ S: P ₂ S ₅ : S: LiBr) was 57.8: 10.2: 17.0: 15.0. Specifically, lithium sulfide 0.3978 g, diphosphorus pentasulfide 0.3352 g, sulfur 0.0805 g, and lithium bromide 0.1926 g were mixed to obtain a raw material mixture. A solid electrolyte was manufactured and evaluated.
The DSC measurement result of the sulfide solid electrolyte obtained in Example 5 is shown in FIG. In DSC measurement, a clear crystallization temperature was not observed, but a minute peak was observed at around 137 ° C. An XRD pattern is shown in FIG.

Example 6
The sulfide solid electrolyte of Example 5 was heat-treated in the same manner as in Example 2. The heat treatment temperature was 140 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 4.4 × 10 ⁻⁴ S / cm.
FIG. 9 shows the XRD pattern of the sulfide solid electrolyte after the heat treatment. 2θ = 26.9, 31.0, 44.5, 53.1 deg, the peak considered to be derived from Li ₂ S, and 2θ = 15.3, 17.7, 25.2, 29.6, Peaks believed to be derived from the aldilodite structure were observed at 31.0, 44.5, 47.3, 51.8, and 58.6 deg. The peak of 2θ = 31.0,44.5deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.

Example 7
Each raw material was mixed so that the molar ratio of the raw material (Li ₂ S: P ₂ S ₅ : S: LiBr) was 42.1: 8.9: 34.0: 15.0. Specifically, 0.3107 g of lithium sulfide, 0.3147 g of diphosphorus pentasulfide, 0.1728 g of sulfur and 0.2067 g of lithium bromide were mixed to obtain a raw material mixture. A solid electrolyte was manufactured and evaluated.
The DSC measurement result of the sulfide solid electrolyte obtained in Example 7 is shown in FIG. In DSC measurement, a clear crystallization temperature was not observed, but a minute peak was observed at around 136 ° C. An XRD pattern is shown in FIG.

Example 8
The sulfide solid electrolyte of Example 7 was heat-treated in the same manner as in Example 2. The heat treatment temperature was 145 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 4.6 × 10 ⁻⁴ S / cm.
The XRD pattern of the sulfide solid electrolyte after heat treatment is shown in FIG. 2θ = 26.8, 30.9, 44.4, 53.0 deg, the peaks considered to be derived from Li ₂ S, and 2θ = 15.2, 17.6, 25.1, 29.5, Peaks thought to be derived from the argilodite structure were observed at 30.9, 44.4, 47.3, 51.7, and 58.4 deg. The peak of 2θ = 30.9,44.4deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.

Example 9
Each raw material was mixed so that the molar ratio of the raw materials (Li ₂ S: P ₂ S ₅ : S: LiBr) was 37.1: 7.9: 30.0: 25.0. Specifically, 0.2625 g of lithium sulfide, 0.2659 g of diphosphorus pentasulfide, 0.1460 g of sulfur, and 0.3298 g of lithium bromide were mixed to obtain a raw material mixture. A solid electrolyte was manufactured and evaluated.
The DSC measurement result of the sulfide solid electrolyte obtained in Example 9 is shown in FIG. In DSC measurement, a clear crystallization temperature was not observed, but a minute peak was observed at around 114 ° C. An XRD pattern is shown in FIG.

Example 10
The sulfide solid electrolyte of Example 9 was heat-treated as in Example 2. The heat treatment temperature was 130 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 9.5 × 10 ⁻⁴ S / cm.
FIG. 15 shows the XRD pattern of the sulfide solid electrolyte after the heat treatment. 2θ = 26.9, 30.9, 44.3, 53.0 deg, the peaks considered to be derived from Li ₂ S, and 2θ = 15.2, 17.6, 25.1, 29.5, Peaks thought to be derived from the aldilodite structure were observed at 30.9, 44.3, 47.2, 51.7, and 58.4 deg. The peak of 2θ = 30.9,44.3deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.

Example 11
Each raw material was mixed so that the molar ratio of the raw materials (Li ₂ S: P ₂ S ₅ : S: LiBr) was 32.2: 6.8: 26.0: 35.0. Specifically, 0.2183 g of lithium sulfide, 0.2211 g of diphosphorus pentasulfide, 0.1214 g of sulfur, and 0.4430 g of lithium bromide were mixed to obtain a raw material mixture. A solid electrolyte was manufactured and evaluated.
The DSC measurement result of the sulfide solid electrolyte obtained in Example 11 is shown in FIG. In DSC measurement, a clear crystallization temperature was not observed, but a minute peak was observed around 120 ° C. An XRD pattern is shown in FIG.

Example 12
The sulfide solid electrolyte of Example 11 was heat-treated as in Example 2. The heat treatment temperature was 135 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 5.2 × 10 ⁻⁴ S / cm.
FIG. 18 shows the XRD pattern of the sulfide solid electrolyte after the heat treatment. 2θ = 26.8, 30.8, a peak considered to be derived from Li ₂ S remaining at the position of 44.3 deg, 2θ = 15.2, 17.6, 25.0, 29.5, 30.8, Peaks thought to be derived from the aldilodite structure were observed at 44.3, 46.6, 51.7, and 58.0 deg. The peak of 2θ = 30.8,44.3deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.

Comparative Example 1
Each raw material was mixed so that the molar ratio of lithium sulfide and diphosphorus pentasulfide (Li ₂ S: P ₂ S ₅ ) was 87.5: 12.5. Specifically, a sulfide solid electrolyte was produced and evaluated in the same manner as in Example 1 except that 0.5913 g of lithium sulfide and 0.4087 g of diphosphorus pentasulfide were mixed to obtain a raw material mixture.
The DSC measurement result of the sulfide solid electrolyte obtained in Comparative Example 1 is shown in FIG. In the DSC measurement, a crystallization peak was observed around 238 ° C. An XRD pattern is shown in FIG.

Comparative Example 2
The sulfide solid electrolyte of Comparative Example 1 was heat-treated as in Example 2. The heat treatment temperature was 550 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 6.4 × 10 ⁻⁶ S / cm.
The XRD pattern of the sulfide solid electrolyte is shown in FIG. 2θ = 15.4, 17.8, 25.3, 29.8, 31.4, 39.6, 44.8, 47.4, 52.1 deg. It was.

Comparative Example 3
Each raw material was mixed so that the molar ratio (Li ₂ S: P ₂ S ₅ : LiBr) of lithium sulfide, phosphorous pentasulfide and lithium bromide (LiBr) was 62.5: 12.5: 25.0 did. Specifically, a sulfide solid electrolyte was produced in the same manner as in Example 1 except that 0.3672 g of lithium sulfide, 0.3552 g of diphosphorus pentasulfide, and 0.2776 g of lithium bromide were mixed to obtain a raw material mixture. ,evaluated.
The DSC measurement result of the sulfide solid electrolyte obtained in Comparative Example 3 is shown in FIG. In DSC measurement, a clear crystallization temperature was not observed, but a minute peak was observed around 182 ° C. An XRD pattern is shown in FIG.

Comparative Example 4
The sulfide solid electrolyte of Comparative Example 3 was heat-treated as in Example 2. The heat treatment temperature was 550 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 2.4 × 10 ⁻³ S / cm.
The XRD pattern of the sulfide solid electrolyte is shown in FIG. Peaks derived from the aldilodite crystal structure were obtained at the positions 2θ = 15.3, 17.7, 25.2, 29.6, 31.0, 44.4, 47.3, 51.8 deg.

Comparative Example 5
Each raw material was mixed so that the molar ratio (Li ₂ S: P ₂ S ₅ : LiBr) of lithium sulfide, diphosphorus pentasulfide, and lithium bromide (LiBr) was 66.1: 16.5: 17.4 did. Specifically, a sulfide solid electrolyte was produced in the same manner as in Example 1 except that 0.3745 g of lithium sulfide, 0.4470 g of diphosphorus pentasulfide, and 0.1843 g of lithium bromide were mixed to obtain a raw material mixture. ,evaluated.
The DSC measurement result of the sulfide solid electrolyte obtained in Comparative Example 5 is shown in FIG. An XRD pattern is shown in FIG. In the DSC measurement, minute peaks were observed around 190 ° C, 222 ° C and 236 ° C.

Comparative Example 6
The sulfide solid electrolyte of Comparative Example 5 was heat-treated as in Example 2. The heat treatment temperature was 250 ° C. The ionic conductivity of the sulfide solid electrolyte after the heat treatment was 2.0 × 10 ⁻⁶ S / cm.
In the XRD pattern of the sulfide solid electrolyte, peaks derived from the aldilodite crystal structure are obtained at the positions of 2θ = 25.0, 29.4, 31.0, 44.6, 47.1, 51.7 deg shown in FIG. It was. The peak of 2θ = 31.0,44.6deg has a peak derived from Li ₂ S, it is inferred that overlaps a peak considered to be derived from Arujirodaito structure.

The sulfide solid electrolyte of the present invention can be used as a constituent material of a lithium ion battery, for example, a positive electrode, a negative electrode, an electrolyte layer, and the like.
The lithium ion battery of the present invention can be used in portable information terminals, portable electronic devices, small household power storage devices, motorcycles powered by motors, electric vehicles, hybrid electric vehicles, and the like.

Claims (7)

Including lithium, phosphorus, sulfur and halogen,
In powder X-ray diffraction (CuKα: λ = 1.5418４), it has diffraction peaks at least at 2θ = 15.2 ± 0.5 deg and 2θ = 17.6 ± 0.5 deg,
A sulfide solid electrolyte satisfying the following formula (1).
0.6 ≦ S _a / S _b ≦ 1.0 (1)
(In the formula, S _a is the area of the diffraction peak at 2θ = 15.2 ± 0.5 deg, and S _b is the area of the diffraction peak at 2θ = 17.6 ± 0.5 deg.) The element ratio (M _Li ) of lithium to the total of the lithium, phosphorus and sulfur, the element ratio (M _P ) of phosphorus, and the element ratio (M _S ) of sulfur satisfy the following formulas (2) to (4). 2. The sulfide solid electrolyte according to 1.
0.350 ≦ M _Li ≦ 0.500 (2)
_{0.010 ≦ M P ≦ 0.150 ··· (} 3)
0.400 ≦ M _S ≦ 0.550 (4)
_{(Wherein, M Li} is the element ratio of lithium, _{M P} is the element ratio of phosphorus, the _{M S} represents an element ratio of sulfur.)   The sulfide solid electrolyte according to claim 1, which has a diffraction peak at 2θ = 25.0 ± 0.5 deg in powder X-ray diffraction (CuKα: λ = 1.5418１．５).   The electrode compound material containing the sulfide solid electrolyte in any one of Claims 1-3, and an active material.   The lithium ion battery containing at least 1 among the sulfide solid electrolyte in any one of Claims 1-3, and the electrode compound material of Claim 4.   The electrode compound material manufactured with the sulfide solid electrolyte in any one of Claims 1-3.   A lithium ion battery manufactured by at least one of the sulfide solid electrolyte according to any one of claims 1 to 3, the electrode mixture according to claim 4, and the electrode mixture according to claim 6.

Images