JP2013037897A - Production method of sulfide solid electrolyte material, and sulfide solid electrolyte material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a sulfide solid electrolyte material having high Li ion conductivity and the amount of hydrogen generation of which is extremely small.SOLUTION: In the production method of a sulfide solid electrolyte material containing Melement (e.g., Li element ), Melement(e.g., Ge element), P element and S element, and having the value of I/Iless than 0.50, where Iis a peak diffraction intensity at the position of 2θ=29.58°±0.50° in the X-ray diffraction measurement using a CuKα ray, and Iis a peak diffraction intensity at 2θ=27.33°±0.50°, the ratio of PSis increased in the raw material composition.

Description

  The present invention relates to a method for producing a sulfide solid electrolyte material having high Li ion conductivity and extremely low hydrogen sulfide generation.

  With the rapid spread of information-related equipment and communication equipment such as personal computers, video cameras, and mobile phones in recent years, development of batteries that are used as power sources has been regarded as important. Also in the automobile industry and the like, development of high-power and high-capacity batteries for electric vehicles or hybrid vehicles is being promoted. Currently, lithium batteries are attracting attention among various batteries from the viewpoint of high energy density.

  Since lithium batteries currently on the market use an electrolyte containing a flammable organic solvent, it is possible to install safety devices that suppress the temperature rise during short circuits and to improve the structure and materials to prevent short circuits. Necessary. In contrast, a lithium battery in which the electrolyte is changed to a solid electrolyte layer to make the battery completely solid does not use a flammable organic solvent in the battery, so the safety device can be simplified, and manufacturing costs and productivity can be reduced. It is considered excellent.

A sulfide solid electrolyte material is known as a solid electrolyte material used for an all solid lithium battery. For example, Non-Patent Document 1 discloses a Li ion conductor (sulfide solid electrolyte material) having a composition of Li _(4-x) Ge _(1-x) P _x S ₄ . Furthermore, this document describes that the Li ion conductivity is highest when x = 0.75, and the Li ion conductivity is 2.2 × 10 ⁻³ S / cm at 25 ° C. It was. In Patent Document 1, Li ₂ S and one or more sulfides selected from P ₂ S ₃ , P ₂ S ₅ , SiS ₂ , GeS ₂ , B ₂ S ₃ , and Al ₂ S ₃ are used. A solid electrolyte material to be synthesized is disclosed.

JP 2009-093995 A

Ryoji Kanno et al., “Lithium Ionic Conductor Thio-LISICON The Li2S-GeS2-P2S5 System”, Journal of The Electrochemical Society, 148 (7) A742-A746 (2001)

  From the viewpoint of increasing the output of a battery, a solid electrolyte material having good ion conductivity is required. According to previous studies by the present inventors, it has been found that a sulfide solid electrolyte material having a high proportion of crystal phase having a specific peak in X-ray diffraction measurement has good ionic conductivity. The crystal structure of the sulfide solid electrolyte material has been clarified by X-ray structural analysis (PCT / JP2011 / 057421).

  This sulfide solid electrolyte material generates less hydrogen sulfide than other sulfide solid electrolyte materials, but even when exposed to the atmosphere, a small amount of hydrogen sulfide is confirmed to be generated. The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a method for producing a sulfide solid electrolyte material having high Li ion conductivity and extremely low hydrogen sulfide generation.

In order to solve the above-mentioned problems, the present inventors conducted extensive research and as a result, obtained a knowledge that a trace amount of hydrogen sulfide is generated from Li ₂ S remaining in the sulfide solid electrolyte material. Further, it was confirmed that the amount of this residual Li ₂ S was so small that it could not be detected by X-ray diffraction. Therefore, the reason why residual Li ₂ S is generated is presumed that P ₂ S ₅ used as a raw material is volatilized at the time of synthesis, and the ratio of P ₂ S ₅ is determined from the stoichiometric ratio of the target composition. As a result, it was found that a sulfide solid electrolyte material with a very small amount of hydrogen sulfide generated can be obtained, and the present invention has been completed.

That is, in the present invention, M ₁ element, M ₂ element, P element and S element are contained, and M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca and Zn. And includes at least Li, and M ₂ is at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. And having at least a tetravalent element and having a peak at a position of 2θ = 29.58 ° ± 0.50 ° in X-ray diffraction measurement using CuKα ray, and the above 2θ = 29.58 ° ± 0. _A sulfide whose value of I _B / I _A is 1 or less, where the diffraction intensity of the peak at 50 ° is I _A and the diffraction intensity of the peak at 2θ = 27.33 ° ± 0.50 ° is I _B a manufacturing method of a solid electrolyte _{material, Li 2 S, P 2 S} 5 Using the raw material composition containing at least the tetravalent element alone or sulfide, an ion conductive material synthesis step for synthesizing an amorphous ion conductive material, and for the ion conductive material, and a heating step of heating so that the value of the _I B / _{I a} is obtained, the ratio of _P 2 _{S 5} in the raw material composition has the general formula _{M 1 (4-x) M} 2 (1- _x) More than the stoichiometric ratio obtained from P _x S ₄ (x satisfies 0 <x <1), and the ratio of raw materials other than P ₂ S ₅ in the raw material composition is obtained from the above general formula. Provided is a method for producing a sulfide solid electrolyte material characterized by having the same stoichiometric ratio.

According to the present invention, even if P ₂ S ₅ volatilization occurs by increasing the proportion of P ₂ S ₅ in the raw material composition to be higher than the stoichiometric ratio of the target composition, residual Li ₂ S Can be eliminated. As a result, a sulfide solid electrolyte material with an extremely small amount of hydrogen sulfide generated can be obtained.

In the above-described invention, the ratio of P ₂ S ₅ in the raw material composition is a sulfide generated from 50 mg of the sulfide solid electrolyte material in the hydrogen sulfide generation amount measurement using a sealed container (volume 1750 cc) filled with air. It is preferable that the hydrogen concentration (after 1 minute exposure to the atmosphere) is 60 ppm or less. This is because a sulfide solid electrolyte material with less hydrogen sulfide generation can be obtained.

In the above invention, the ratio of P ₂ S ₅ in the raw material composition is such that the diffraction intensity of the peak at 2θ = 29.58 ° ± 0.50 ° is I _A, and 2θ = 26.10 ° ± 0.50. the diffraction intensity of the peak of ° when the I _D, it is preferable the value of I D _/ I _a is a ratio of 1 or less. This is because a decrease in Li ion conductivity can be suppressed.

In the above invention, the ratio of P ₂ S ₅ in the raw material composition is, with respect to the stoichiometric ratio obtained from the above formula, it is preferably larger in the range of 5% to 20% by weight.

In the present invention, _{M 1} element, _{M 2} element contains a P element and S elements, said _{M 1} is, Li, Na, K, Mg, Ca, with at least one selected from the group consisting of Zn And includes at least Li, and M ₂ is at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. And having at least a tetravalent element and having a peak at a position of 2θ = 29.58 ° ± 0.50 ° in X-ray diffraction measurement using CuKα ray, and the above 2θ = 29.58 ° ± 0. the diffraction intensity of the peak of 50 ° and _{I a, 2θ} = 27.33 the diffraction intensity of the peak of ° ± 0.50 ° when the _{I B,} the value of I B / _{I a} is 1 or less, CuKa 2θ = 2.10 ° ± 0.50 ° in X-ray diffraction measurement using X-rays Having peaks at the diffraction intensity of the peak of the 2θ = 26.10 ° ± 0.50 ° when the _{I D,} the value of I D / _{I A} is in the range of 0.01 to 1 A sulfide solid electrolyte material is provided.

According to the present invention, by making the value of I D _/ I _A within a predetermined range, it is possible to sulfide solid electrolyte material which suppresses the amount of produced hydrogen sulfide.

  In the present invention, there is an effect that a sulfide solid electrolyte material having a high Li ion conductivity and an extremely small amount of hydrogen sulfide generated can be obtained.

It is explanatory drawing which shows an example of the manufacturing method of the sulfide solid electrolyte material of this invention. It is explanatory drawing which shows the other example of the manufacturing method of the sulfide solid electrolyte material of this invention. It is an X-ray diffraction spectrum explaining the difference between a sulfide solid electrolyte material with high Li ion conductivity and a sulfide solid electrolyte material with low Li ion conductivity. It is a perspective view explaining an example of the crystal structure of the sulfide solid electrolyte material obtained by this invention. It is the result of the hydrogen sulfide generation amount measurement with respect to the sulfide solid electrolyte material obtained in Examples 1-3 and the comparative example 1. FIG. It is the result of the hydrogen sulfide generation amount measurement with respect to the sulfide solid electrolyte material obtained in Examples 1-3 and the comparative example 1. FIG. It is a measurement result of Li ion conductivity with respect to the sulfide solid electrolyte material obtained in Examples 1-3 and Comparative Example 1. 2 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Examples 1 to 3 and Comparative Example 1. FIG. The value of _{I D} / I _A, is a graph showing the relationship between the Li ion conductivity.

  Hereinafter, the manufacturing method of the sulfide solid electrolyte material of the present invention and the sulfide solid electrolyte material will be described.

A. First, a method for producing a sulfide solid electrolyte material of the present invention will be described. The manufacturing method of the sulfide solid electrolyte material of the present invention contains M ₁ element, M ₂ element, P element and S element, and the above M ₁ is selected from the group consisting of Li, Na, K, Mg, Ca and Zn. At least one selected and containing at least Li, and the M ₂ is selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb And at least one tetravalent element, and has a peak at a position of 2θ = 29.58 ° ± 0.50 ° in X-ray diffraction measurement using CuKα rays, and the above 2θ = 29 the diffraction intensity of the peak of .58 ° ± 0.50 ° and _{I a,} the diffraction intensity of the peak of 2θ = 27.33 ° ± 0.50 ° when the _{I B,} the value of I B / _{I a} A method for producing a sulfide solid electrolyte material that is 1 or less, comprising Li ₂ S , P ₂ S ₅ , an ion conductive material synthesizing step of synthesizing an amorphous ion conductive material using a raw material composition containing at least a tetravalent element or a sulfide, and the ion conduction The heating material is heated so that the value of I _B / I _A is obtained, and the ratio of P ₂ S ₅ in the raw material composition is represented by the formula M _{1 (4-x )} M _{2 (1-x)} P _x S ₄ (x satisfies 0 <x <1), and the proportion of raw materials other than P ₂ S ₅ in the raw material composition is larger than the stoichiometric ratio. The stoichiometric ratio obtained from the above general formula is the same.

According to the present invention, even if P ₂ S ₅ volatilization occurs by increasing the proportion of P ₂ S ₅ in the raw material composition to be higher than the stoichiometric ratio of the target composition, residual Li ₂ S Can be eliminated. As a result, a sulfide solid electrolyte material with an extremely small amount of hydrogen sulfide generated can be obtained. In addition, the sulfide solid electrolyte material obtained by the present invention has a high proportion of crystal phase having a peak around 2θ = 29.58 °, and thus can be a sulfide solid electrolyte material having good Li ion conductivity. . Therefore, a high output battery can be obtained by using this sulfide solid electrolyte material. _{Incidentally,} probably because the melting point of P 2 _{S 5} is about 270 ° C., volatilizes during synthesis. In the present invention, the amount of P ₂ S ₅ larger than the stoichiometric ratio of the target composition may be referred to as P ₂ S ₅ excessive addition amount.

FIG. 1 is an explanatory view showing an example of a method for producing a sulfide solid electrolyte material of the present invention. In FIG. 1, first, a raw material composition is prepared by mixing Li ₂ S, P ₂ S ₅ and GeS ₂ . At this time, the proportion of P ₂ S ₅ in the raw material composition is made larger than the stoichiometric ratio of the target composition, and the proportion of Li ₂ S and GeS ₂ in the raw material composition is changed to the stoichiometric amount of the target composition. Same as the reasoning ratio. Next, ball milling (mechanical milling) is performed on the raw material composition to obtain an amorphous ion conductive material. Next, the amorphous ion conductive material is heated to improve the crystallinity, thereby obtaining a sulfide solid electrolyte material.

FIG. 2 is an explanatory view showing another example of the method for producing a sulfide solid electrolyte material of the present invention. In FIG. 2, first, a raw material composition is prepared by mixing Li ₂ S, P ₂ S ₅ and GeS ₂ . At this time, the proportion of P ₂ S ₅ in the raw material composition is made larger than the stoichiometric ratio of the target composition, and the proportion of Li ₂ S and GeS ₂ in the raw material composition is changed to the stoichiometric amount of the target composition. Same as the reasoning ratio. Next, the raw material composition is heated in a vacuum to obtain a crystalline ion conductive material by a solid phase reaction. Next, vibrational milling (mechanical milling) is performed on the obtained crystalline ion conductive material to obtain an amorphous ion conductive material. Next, the amorphous ion conductive material is heated to improve the crystallinity, thereby obtaining a sulfide solid electrolyte material.

In addition, the amorphized ion conductive material in the present invention refers to a material whose crystallinity is lower than the material before amorphization, and does not need to be completely amorphous. The sulfide solid electrolyte material obtained by the present invention will be described in detail in “3. Sulfide solid electrolyte material”. In the present invention, the proportion of materials other than P ₂ S ₅ in the raw material composition, the same as the stoichiometric ratio obtained from the formula described below. “Same as stoichiometric ratio” means not only a proportion that is exactly the same as the stoichiometric ratio but also within a range of ± 10 wt% (especially ± 5 wt. %, Particularly within the range of ± 3% by weight).
Hereafter, the manufacturing method of the sulfide solid electrolyte material of this invention is demonstrated for every process.

1. Ion conductive material synthesizing step The ion conductive material synthesizing step in the present invention is performed by using a raw material composition containing at least Li ₂ S, P ₂ S ₅ , a simple substance or a sulfide of the tetravalent element, and an amorphous material. This is a step of synthesizing the ionized conductive material. Furthermore, the ratio of P ₂ S ₅ in the raw material composition is a chemistry determined from the general formula M _{1 (4-x)} M _{2 (1-x)} P _x S ₄ (x satisfies 0 <x <1). More than the stoichiometric ratio, the ratio of raw materials other than P ₂ S ₅ in the raw material composition is the same as the stoichiometric ratio determined from the above general formula.

First, the general formula _{M 1 (4-x) M} 2 (1-x) P x S 4 (x is 0 satisfy <x <1) will be described. Hereinafter, this general formula may be referred to as general formula (1). As mentioned above, the sulfide solid electrolyte material obtained by the present invention comprises at least Li as M _1, comprising at least tetravalent element (the M ₂ ^IV) as M _2. Here, the composition on the tie line of Li ₃ PS ₄ and Li ₄ (M ₂ ^IV ) S ₄ is represented by the general formula Li _4-x (M ₂ ^IV ) _1-x P _x S ₄ (x is 0 <Satisfying x <1). Hereinafter, this general formula may be referred to as general formula (2).

In the general formula (2), Li ₃ PS ₄ and Li ₄ (M ₂ ^IV ) S ₄ each correspond to an ortho composition. The term “ortho” generally refers to an oxo acid obtained by hydrating the same oxide with the highest degree of hydration. In the present invention, the crystal composition in which Li ₂ S is added most in the sulfide is called the ortho composition. Li ₃ PS ₄ corresponds to the ortho composition in the Li ₂ S—P ₂ S ₅ system, and Li ₄ (M ₂ ^IV ) S ₄ corresponds to the ortho composition in the Li ₂ S— (M ₂ ^IV ) S ₂ system. To do. Ortho sulfide sulfide solid electrolyte materials have the advantage of high chemical stability. The general formula (2) is a composition on the tie line of Li ₃ PS ₄ and Li ₄ (M ₂ ^IV ) S ₄ each having an ortho composition, so that the sulfur is high in chemical stability and generates a small amount of hydrogen sulfide. A solid electrolyte material can be obtained.

The ratio of Li ₂ S and P ₂ S ₅ to obtain Li ₃ PS ₄ is Li ₂ S: P ₂ S ₅ = 75: 25 on a molar basis. On the other hand, the ratio of Li ₂ S and (M ₂ ^IV ) S ₂ to obtain Li ₄ (M ₂ ^IV ) S ₄ is Li ₂ S: (M ₂ ^IV ) S ₂ = 66.7: 33. 3. Therefore, if x is fixed in the general formula (2), the stoichiometric ratio of P ₂ S ₅ can be calculated from the general formula (2).

When M ₂ is a trivalent element (M ₂ ^III ), the ortho composition in the Li ₂ S— (M ₂ ^III ) ₂ S ₃ system is Li ₃ (M ₂ ^III ) S ₃ , and Li ₃ The ratio of Li ₂ S to obtain (M ₂ ^III ) S ₃ and (M ₂ ^III ) ₂ S ₃ is, on a molar basis, Li ₂ S: (M ₂ ^III ) ₂ S ₃ = 75: 25. Further, when M ₂ is a pentavalent element (M ₂ ^V ), the ortho composition in the Li ₂ S— (M ₂ ^V ) ₂ S ₅ system is Li ₃ (M ₂ ^V ) S ₄ , and Li _{3 (M} ² V) ratio of Li ₂ S and ^_(M 2 _V) 2 _{S 5} to obtain a _{S 4} are on a molar ^{_{basis, Li 2 S: (M 2}} V) 2 S 5 = 75: 25. Thus, for example, even when the valence of M ₂ is changed, the stoichiometric ratio of P ₂ S ₅ can be calculated.

General formula (1) is an extension of general formula (2). That, _{M 1} in the general formula (1) _is not M 1 = Li only tolerate substitution with other _{M 1} element, _{M 2} in the general formula (1) _is not only _{M 2} = M 2 ^IV , Substitution with a plurality of M ₂ ^IVs , substitution with elements having different valences, and the like are allowed. Further, in M _{1 (4-x)} M _{2 (1-x)} P _x S ₄ , x satisfies 0 <x <1. The value of x is not particularly limited, but is preferably 0.4 or more, more preferably 0.5 or more, and still more preferably 0.6 or more. Similarly, the value of x is, for example, preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.75 or less.

Here, in the general formula (1), M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca, and Zn. Among these, monovalent M ₁ (referred to as M ₁ ^I ) is Li, Na, K, and divalent M ₁ (referred to as M ₁ ^II ) is Mg, Ca, Zn. Depending on the valence of M ₁ , the general formula (1) can also be described as follows, for example.
<General formula (1a)>
(Li _1-δ (M ₁ ^II ) _0.5δ ) _(4-x) M _{2 (1-x)} P _x S ₄
In the general formula (1a), for example, it is considered that Li ion conductivity is improved by replacing a part of Li with divalent M ₁ . In the general formula (1a), x satisfies 0 <x <1. δ satisfies 0 <x <1, and preferably satisfies 0.5 ≦ x ≦ 0.8.

On the other hand, in the general formula (1), M ₂ is at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. Among these, trivalent M ₂ (referred to as M ₂ ^III ) is B, Al, Ga, In, Sb, and tetravalent M ₂ (referred to as M ₂ ^IV ) is defined as Si, Ti, Ge, Zr, Sn, and Nb, and pentavalent M ₂ (referred to as M ₂ ^V ) is P, V, and Sb.

Also, depending on the valence of M _2, the general formula (1) may, for example, can be described as follows. In general formulas (1b) to (1d), x satisfies 0 <x <1. δ satisfies 0 <x <1, and preferably satisfies 0.5 ≦ x ≦ 0.8.
<General formula (1b)>
Li _(4-x) ((M ₂ ^IV ) _1-δ (M ₁ ^I ) _δ (M ₂ ^III ) _δ ) _(1-x) P _x S ₄
<General formula (1c)>
Li _(4-x) ((M ₂ ^IV ) _1-δ (M ₂ ^III ) _0.5δ (M ₂ ^V ) _0.5δ ) _(1-x) P _x S ₄
<General formula (1d)>
(Li _1-δ (M ₁ ^II ) _δ ) _(4-x) ((M ₂ ^IV ) _1-δ (M ₂ ^III ) _δ ) _(1-x) P _x S ₄

The raw material composition in the present invention contains at least Li ₂ S, P ₂ S ₅ , the above tetravalent element alone or a sulfide. The raw material composition may contain a simple substance or a sulfide of the M ₁ element and the M ₂ element.

In the present invention, the proportion of P ₂ S ₅ in the raw material composition is made larger than the stoichiometric ratio obtained from the general formula (1). Especially, it is preferable that the ratio of P ₂ S ₅ is a ratio at which the concentration of generated hydrogen sulfide is reduced in a predetermined hydrogen sulfide generation amount measurement. As a method for measuring the amount of hydrogen sulfide generated, 50 mg of the sulfide solid electrolyte material obtained according to the present invention is placed in a sealed container (volume: 1750 cc) filled with air, and the concentration of hydrogen sulfide generated by exposure to the air is measured. Can be mentioned. The proportion of P ₂ S ₅ is preferably such that the hydrogen sulfide concentration after 1 minute exposure to the atmosphere is 60 ppm or less, more preferably 40 ppm or less, and 20 ppm or less. More preferably. This is because a safer sulfide solid electrolyte material can be obtained.

The ratio of the P ₂ S _5, it is preferable ratio of the crystalline phase D caused by excess P ₂ S ₅ is a fraction of a degree that does not become too large. The crystal phase D is considered to be a crystal phase having a lower Li ion conductivity than the crystal phase A described later in “3. Sulfide solid electrolyte material”, and lowers the Li ion conductivity of the sulfide solid electrolyte material. It is. The crystal phase D has a peak in the vicinity of 2θ = 26.10 ° in X-ray diffraction measurement using CuKα rays. Here, 2θ = 26.10 ° is an actual measurement value obtained in an example described later, and the crystal lattice slightly changes depending on the material composition and the like, and the peak position slightly changes from 2θ = 26.10 °. There is. Therefore, in the present invention, the peak of the crystal phase D is defined as a peak at a position of 26.10 ° ± 0.50 °. Crystal phase D is usually considered to have peaks at 2θ = 26.10 °, 29.86 °, 30.12 °, and 17.96 °. Note that these peak positions may also fluctuate within a range of ± 0.50 °.

Further, when the diffraction intensity of the peak at 2θ = 29.58 ° ± 0.50 ° is I _A and the diffraction intensity of the peak at 2θ = 26.10 ° ± 0.50 ° is _ID , the above P ₂ ratio of S ₅ is typically a percentage of the value of I D _/ I _a is 1 or less, more preferably the rate at which preferably a ratio of 0.5 or less, 0.4 or less The ratio is more preferably 0.2 or less, and particularly preferably 0.1 or less. Note that the I _A, is described in detail in "3. sulfide solid electrolyte material" to be described later. The ratio of P ₂ S ₅ in the raw material composition, to the general formula (1) stoichiometry obtained from, for example, it is preferably larger in the range of 5% to 20% by weight.

  A method for synthesizing the amorphous ion conductive material is not particularly limited. As an example of a method for synthesizing the amorphous ion conductive material, a method of performing mechanical milling on the raw material composition can be given.

  Mechanical milling is a method of crushing a sample while applying mechanical energy. An amorphous ion conductive material can be synthesized by applying mechanical energy to the raw material composition. Examples of such mechanical milling include a ball mill, a vibration mill, a turbo mill, a mechanofusion, and a disk mill.

  Various conditions of mechanical milling are set so that a desired ion conductive material can be obtained. For example, when a planetary ball mill is used, a raw material composition and grinding balls are added, and the treatment is performed at a predetermined number of revolutions and time. In general, the higher the number of rotations, the faster the production rate of the ion conductive material, and the longer the treatment time, the higher the conversion rate from the raw material composition to the ion conductive material. The rotation speed of the base plate when performing the planetary ball mill is preferably in the range of, for example, 200 rpm to 500 rpm, and more preferably in the range of 250 rpm to 400 rpm. Further, the treatment time when performing the planetary ball mill is preferably in the range of, for example, 1 hour to 100 hours, and more preferably in the range of 1 hour to 70 hours.

  In the case of a vibration mill, the vibration amplitude of the vibration mill is preferably in the range of, for example, 5 mm to 15 mm, and more preferably in the range of 6 mm to 10 mm. The vibration frequency of the vibration mill is, for example, preferably in the range of 500 rpm to 2000 rpm, and more preferably in the range of 1000 rpm to 1800 rpm. The filling rate of the raw material composition in the vibration mill is, for example, in the range of 1% by volume to 80% by volume, especially in the range of 5% by volume to 60% by volume, particularly in the range of 10% by volume to 50% by volume. preferable. Moreover, it is preferable to use a vibrator (for example, an alumina vibrator) for the vibration mill.

  In addition, as another example of the method for synthesizing the amorphized ion conductive material, first, a crystalline ion conductive material is synthesized from the raw material composition, and then the obtained crystalline ion conductive material is synthesized. A method of performing mechanical milling on the material can be mentioned. Examples of a method for synthesizing a crystalline ion conductive material from a raw material composition include a solid phase method. The solid phase method is a method of synthesizing a target compound by a solid phase reaction by heating. The heating temperature in the solid phase method is not particularly limited as long as it is a temperature at which a solid phase reaction occurs between the compounds contained in the raw material composition. Although heating temperature changes with compositions of a raw material composition, it is preferable to exist in the range of 300 to 1000 degreeC, for example, and it is more preferable to exist in the range of 500 to 900 degreeC. The heating time is preferably adjusted as appropriate so that a desired ion conductive material can be obtained. The heating in the solid phase method is preferably performed in an inert gas atmosphere or in vacuum from the viewpoint of preventing oxidation. Since the mechanical milling for the crystalline ion conductive material is the same as described above, the description is omitted here.

2. Next, the heating process in the present invention will be described. Heating step of the present invention, with respect to the ion-conductive material is a step of heating so that the value of the I _{B /} I _A is obtained.

  In the heating step, the crystallinity is improved by heating the amorphous ion conductive material. By performing this heating, the crystal phase A having high ion conductivity (a crystal phase having a peak near 2θ = 29.58 °) can be positively precipitated.

  The heating temperature is not particularly limited as long as the desired sulfide solid electrolyte material can be obtained. Crystallization of crystal phase A (crystal phase having a peak around 2θ = 29.58 °) It is preferable that the temperature is higher than the temperature. Specifically, the heating temperature is preferably 300 ° C. or higher, more preferably 350 ° C. or higher, further preferably 400 ° C. or higher, and particularly preferably 450 ° C. or higher. On the other hand, the heating temperature is preferably 1000 ° C. or less, more preferably 700 ° C. or less, further preferably 650 ° C. or less, and particularly preferably 600 ° C. or less. Moreover, it is preferable to adjust a heating time suitably so that a desired sulfide solid electrolyte material may be obtained. The heating in the heating step is preferably performed in an inert gas atmosphere or in a vacuum from the viewpoint of preventing oxidation.

3. Sulfide solid electrolyte material The sulfide solid electrolyte material obtained by the present invention contains M ₁ element, M ₂ element, P element and S element, and the above M ₁ is Li, Na, K, Mg, Ca, Zn. And at least one selected from the group consisting of Li, and M ₂ is selected from P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. And at least one selected from the group consisting of at least a tetravalent element and having a peak at a position of 2θ = 29.58 ° ± 0.50 ° in X-ray diffraction measurement using CuKα rays, When the diffraction intensity of the peak at 2θ = 29.58 ° ± 0.50 ° is I _A and the diffraction intensity of the peak at 2θ = 27.33 ° ± 0.50 ° is I _B , I _B / I _A Is 1 or less.

FIG. 3 is an X-ray diffraction spectrum for explaining a difference between a sulfide solid electrolyte material having high Li ion conductivity and a sulfide solid electrolyte material having low Li ion conductivity. Note that the two sulfide solid electrolyte materials in FIG. 3 both have a composition of Li _3.25 Ge _0.25 P _0.75 S ₄ . In FIG. 3, the sulfide solid electrolyte material having high Li ion conductivity has a peak at a position of 2θ = 29.58 ° ± 0.50 ° and a position of 2θ = 27.33 ° ± 0.50 °. . Moreover, in FIG. 3, the sulfide solid electrolyte material with low Li ion conductivity also has the same peak. Here, it is considered that the crystal phase having a peak near 2θ = 29.58 ° and the crystal phase having a peak near 2θ = 27.33 ° are different crystal phases. In the present invention, a crystal phase having a peak near 2θ = 29.58 ° is referred to as “crystal phase A”, and a crystal phase having a peak near 2θ = 27.33 ° is referred to as “crystal phase B”. There is a case.

  Crystal phases A and B are both crystal phases exhibiting Li ion conductivity, but there are differences in Li ion conductivity. The crystal phase A is considered to have significantly higher Li ion conductivity than the crystal phase B. In the conventional synthesis method (for example, solid phase method), the proportion of the crystal phase B having low Li ion conductivity cannot be reduced, and the Li ion conductivity cannot be sufficiently increased. On the other hand, in this invention, since the crystal phase A with high Li ion conductivity can be positively precipitated, the sulfide solid electrolyte material with high Li ion conductivity can be obtained.

The reason why the crystal phase A having high Li ion conductivity can be positively precipitated is considered as follows. In the present invention, an amorphous ion conductive material is synthesized once. As a result, the crystal phase A having high Li ion conductivity (crystal phase having a peak near 2θ = 29.58 °) is likely to precipitate, and the crystal phase A is positively precipitated by the subsequent heating step. It is considered that the value of I _B / I _A can be set to a value (specifically, less than 0.50) that was impossible in the past. The reason why the crystal phase A easily precipitates is not completely clear, but the solid solution region in the ion conductive material changes due to mechanical milling or the like, and the environment in which the crystal phase A hardly precipitates is likely to precipitate. There is a possibility that it has changed.

In the present invention, to distinguish the Li ion conductivity is low sulfide solid electrolyte material, the diffraction intensity of the peak near 2 [Theta] = 29.58 ° and I _A, 2 [Theta] = 27.33 peak around ° the diffraction intensity and _{I B,} defines the value of I B / _{I a} to 1 or less. From the viewpoint of Li ion conductivity, it is preferable that the ratio of the crystal phase A in the sulfide solid electrolyte material is high. Therefore, the value of I _B / I _A is preferably smaller, specifically, preferably 0.45 or less, more preferably 0.25 or less, and 0.15 or less. More preferably, it is particularly preferably 0.07 or less. Further, the value of I _B / I _A is preferably 0. In other words, the sulfide solid electrolyte material obtained by the present invention preferably does not have a peak around 2θ = 27.33 °, which is the peak of the crystal phase B.

  The sulfide solid electrolyte material obtained by the present invention has a peak in the vicinity of 2θ = 29.58 °. As described above, this peak is one of the peaks of the crystal phase A having high Li ion conductivity. Here, 2θ = 29.58 ° is an actual measurement value, and the crystal lattice changes slightly depending on the material composition and the like, and the peak position may slightly vary from 2θ = 29.58 °. Therefore, in the present invention, the peak of the crystal phase A is defined as a peak at a position of 29.58 ° ± 0.50 °. Crystalline phase A is usually 2θ = 17.38 °, 20.18 °, 20.44 °, 23.56 °, 23.96 °, 24.93 °, 26.96 °, 29.07 °, 29 It is considered to have peaks at .58 °, 31.71 °, 32.66 ° and 33.39 °. Note that these peak positions may also fluctuate within a range of ± 0.50 °.

  On the other hand, the peak around 2θ = 27.33 ° is one of the peaks of the crystal phase B having low Li ion conductivity, as described above. Here, 2θ = 27.33 ° is an actual measurement value, and the crystal lattice may slightly change depending on the material composition and the like, and the peak position may slightly vary from 2θ = 27.33 °. Therefore, in the present invention, the peak of the crystal phase B is defined as a peak at a position of 27.33 ° ± 0.50 °. Crystalline phase B usually has peaks at 2θ = 17.46 °, 18.12 °, 19.99 °, 22.73 °, 25.72 °, 27.33 °, 29.16 °, 29.78 °. It is thought that it has. Note that these peak positions may also fluctuate within a range of ± 0.50 °.

Further, as shown in FIG. 3, the crystal phase B having low Li ion conductivity has a peak in the vicinity of 2θ = 29.78 ° in addition to the vicinity of 2θ = 27.33 °. When the diffraction intensity of the peak at 2θ = 29.58 ° ± 0.50 ° is I _A and the diffraction intensity of the peak at 2θ = 29.78 ° ± 0.50 ° is I _C , I _C / I The value of _A is preferably 0.20 or less, more preferably 0.15 or less, further preferably 0.10 or less, and particularly preferably 0.07 or less. The value of I _C / I _A is preferably 0. In other words, the sulfide solid electrolyte material obtained by the present invention preferably has no peak around 2θ = 29.78 °, which is the peak of the crystal phase B. Note that 2θ = 29.78 ° ± 0.50 ° is usually adopted as the peak position showing the crystal phase B, but it may be 2θ = 29.78 ° ± 0.20 °.

Further, the sulfide solid electrolyte material obtained by the present invention includes an octahedron O composed of M ₁ element and S element, a tetrahedron T ₁ composed of M _2a element and S element, M _2b element and S The tetrahedron T ₂ composed of elements, the tetrahedron T ₁ and the octahedron O share a ridge, and the tetrahedron T ₂ and the octahedron O mainly have a crystal structure sharing a vertex. It is preferable to contain. M ₁ is usually at least one selected from the group consisting of Li, Na, K, Mg, Ca, and Zn, and contains at least Li. The M _2a is usually at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb, and is at least tetravalent. Contains elements. The M _2b is usually at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb, and contains at least P. It is a waste.

FIG. 4 is a perspective view for explaining an example of the crystal structure of the sulfide solid electrolyte material obtained by the present invention. In the crystal structure shown in FIG. 4, the octahedron O has M ₁ as a central element, has six S at the apex of the octahedron, and is typically a LiS ₆ octahedron. The tetrahedron T ₁ has M _2a as a central element, has four S at the apex of the tetrahedron, and is typically both a GeS ₄ tetrahedron and a PS ₄ tetrahedron. Tetrahedron T ₂ are, has M _2b as the central element, has four S to the apex of the tetrahedron, typically PS ₄ tetrahedron. Furthermore, the tetrahedron T ₁ and the octahedron O share a ridge, and the tetrahedron T ₂ and the octahedron O share a vertex.

  The sulfide solid electrolyte material obtained by the present invention preferably contains the above crystal structure as a main component. The ratio of the crystal structure in the entire crystal structure of the sulfide solid electrolyte material is not particularly limited, but is preferably higher. It is because it can be set as the sulfide solid electrolyte material with high Li ion conductivity. Specifically, the proportion of the crystal structure is preferably 70% by weight or more, and more preferably 90% by weight or more. In addition, the ratio of the said crystal structure can be measured by synchrotron radiation XRD, for example.

The sulfide solid electrolyte material obtained by the present invention is usually a crystalline sulfide solid electrolyte material. The sulfide solid electrolyte material preferably has high Li ion conductivity, and the Li ion conductivity of the sulfide solid electrolyte material at 25 ° C. is 1.0 × 10 ⁻³ S / cm or more. Preferably, it is 2.3 × 10 ⁻³ S / cm or more. Further, the shape of the sulfide solid electrolyte material is not particularly limited, and examples thereof include a powder form. Furthermore, the average particle diameter of the powdered sulfide solid electrolyte material is preferably in the range of 0.1 μm to 50 μm, for example.

  The sulfide solid electrolyte material obtained by the present invention can be used for any application that requires Li ion conductivity. Especially, it is preferable that this sulfide solid electrolyte material is used for a battery. This is because it can greatly contribute to the high output of the battery. Moreover, the sulfide solid electrolyte material obtained by this invention can be used for the positive electrode active material layer, electrolyte layer, or negative electrode active material layer which comprises a battery. Furthermore, in the present invention, it is also possible to provide a battery manufacturing method using the sulfide solid electrolyte material obtained by the above-described sulfide solid electrolyte material manufacturing method.

B. Next, the sulfide solid electrolyte material of the present invention will be described. The sulfide solid electrolyte material of the present invention contains M ₁ element, M ₂ element, P element and S element, and M ₁ is selected from the group consisting of Li, Na, K, Mg, Ca and Zn. At least one and at least Li, and the M ₂ is at least selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb It is a kind, contains at least a tetravalent element, has a peak at a position of 2θ = 29.58 ° ± 0.50 ° in X-ray diffraction measurement using CuKα ray, and the above 2θ = 29.58 ° the diffraction intensity of the peak of ± 0.50 ° and _{I a,} the diffraction intensity of the peak of 2θ = 27.33 ° ± 0.50 ° when the _{I B,} the value of I B / _{I a} is 1 or less Yes, 2θ = 26.10 ° ± 0 in X-ray diffraction measurement using CuKα ray Having peaks at .50 °, the 2 [Theta] = 26.10 diffraction intensity of the peak of ° ± 0.50 ° when the _{I D,} the range value of the I D / _{I A} is 0.01 It is characterized by being within.

According to the present invention, by making the value of I D _/ I _A within a predetermined range, it is possible to sulfide solid electrolyte material which suppresses the amount of produced hydrogen sulfide. As described above, the peak near 26.10 ° is a peak of a crystal phase generated by excess P ₂ S ₅ . This crystal phase (crystal phase D) is considered to be a crystal phase having a lower Li ion conductivity than the crystal phase A. From the viewpoint of Li ion conductivity, the proportion of the crystal phase D is preferably small. On the other hand, the presence of the crystal phase D effectively suppresses the amount of hydrogen sulfide generated. Therefore, in view of the hydrogen sulfide suppression, peak near 26.10 ° is confirmed by XRD, it is preferable that the value of I D _/ I _A within a predetermined range. The sulfide solid electrolyte material of the present invention is basically the same as the contents described in “A. Method for producing sulfide solid electrolyte material 3. Sulfide solid electrolyte material” described above. Description is omitted.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
As starting materials, lithium sulfide (Li ₂ S, manufactured by Nippon Chemical Industry Co., Ltd.), diphosphorus pentasulfide (P ₂ S ₅ , manufactured by Nippon Chemical Industry Co., Ltd.), and germanium sulfide (GeS ₂ , manufactured by High Purity Chemical Research Laboratory) And were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.393458 g of Li ₂ S, 0.299104 g of P ₂ S ₅ and 0.334629 g of GeS ₂ to obtain a raw material composition. The above composition _is a _{Li 3.39 Ge 0.48 P 0.53 S 4} , in the composition of x = 0.5 in _{Li (4-x) Ge (} 1-x) P x S 4, P Corresponds to ₂ S ₅ added in excess of 10% by weight. Next, 1 g of the raw material composition was placed in a zirconia pot (45 ml) together with zirconia balls (10 mmφ, 10 pieces), and the pot was completely sealed (argon atmosphere). This pot was attached to a planetary ball mill (P7 made by Fritsch), and mechanical milling was performed at a base plate rotation speed of 370 rpm for 40 hours. Thereby, an amorphous ion conductive material was obtained.

  Next, the obtained ion conductive material was molded into pellets, and the obtained pellets were placed in a carbon-coated quartz tube and vacuum-sealed. The pressure of the vacuum sealed quartz tube was about 30 Pa. Next, the quartz tube was placed in a firing furnace, heated from room temperature to 550 ° C. over 6 hours, maintained at 550 ° C. for 8 hours, and then gradually cooled to room temperature. As a result, a crystalline sulfide solid electrolyte material was obtained.

[Example 2]
The crystalline sulfide was obtained in the same manner as in Example 1 except that the raw material composition was obtained by mixing Li ₂ S at a rate of 0.393458 g, P ₂ S ₅ at a rate of 0.29105 g, and GeS ₂ at a rate of 0.334629 g. A solid electrolyte material was obtained. The above composition _is a _{Li 3.42 Ge 0.52 P 0.49 S 4} , in the composition of x = 0.5 in _{Li (4-x) Ge (} 1-x) P x S 4, P Corresponds to ₂ S ₅ added in excess of 5% by weight.

[Example 3]
The crystalline sulfide was obtained in the same manner as in Example 1 except that the raw material composition was obtained by mixing Li ₂ S at a rate of 0.393458 g, P ₂ S ₅ at a rate of 0.326283 g, and GeS ₂ at a rate of 0.334629 g. A solid electrolyte material was obtained. The above composition _is a _{Li 3.29 Ge 0.56 P 0.47 S 4} , in the composition of x = 0.5 in _{Li (4-x) Ge (} 1-x) P x S 4, P Corresponds to ₂ S ₅ added in excess of 20% by weight.

[Comparative Example 1]
The crystalline sulfide was obtained in the same manner as in Example 1 except that the raw material composition was obtained by mixing Li ₂ S at a rate of 0.393458 g, P ₂ S ₅ at a rate of 0.271912 g, and GeS ₂ at a rate of 0.334629 g. A solid electrolyte material was obtained. The above composition _{is Li 3.5 Ge 0.5 P 0.5 S 4} , which corresponds to the composition of x = 0.5 in _{Li (4-x) Ge (} 1-x) P x S 4 .

[Evaluation 1]
(Measurement of hydrogen sulfide generation)
The amount of hydrogen sulfide generated was measured for the sulfide solid electrolyte materials obtained in Examples 1 to 3 and Comparative Example 1. The amount of hydrogen sulfide generated was measured as follows. Under an Ar atmosphere, 50 mg of the sulfide solid electrolyte material was weighed and placed in an airtight container (volume 1750 cc, temperature 32 ° C., humidity 38%) filled with air. The inside of the sealed container was stirred with a fan, and a hydrogen sulfide sensor (manufactured by Riken Keiki Co., Ltd., GX-2009, TYPE-E) was used for measurement. The time-dependent change of the hydrogen sulfide concentration in the sealed container is shown in FIG. 5, and the hydrogen sulfide concentration in the sealed container after 1 minute exposure to the atmosphere is shown in FIG.

As shown in FIGS. 5 and 6, in Examples 1 to 3, it was confirmed that the amount of hydrogen sulfide generated was reduced as compared with Comparative Example 1 by adding P ₂ S ₅ excessively.

(Li ion conductivity measurement)
Li ion conductivity was measured for the sulfide solid electrolyte materials obtained in Examples 1 to 3 and Comparative Example 1. First, put 200 mg of sample in a support tube (1 cm ² ) made by Macor, sandwich the sample with an electrode made by SKD, compact it with a pressure of 4.3 ton / cm ² , and measure impedance while restraining at 6 Ncm. went. Thereafter, Li ion conductivity was calculated from the thickness and resistance of the sample (pellet). The result is shown in FIG. As shown in FIG. 7, the sulfide solid electrolyte material obtained in Example 3 was slightly inferior to the sulfide solid electrolyte material obtained in Comparative Example 1 from the viewpoint of Li ion conductivity, but Example 1 It was confirmed that the sulfide solid electrolyte material obtained in 2 exhibited a high Li ion conductivity equivalent to that of the sulfide solid electrolyte material obtained in Comparative Example 1.

(X-ray diffraction measurement)
X-ray diffraction (XRD) measurement was performed on the sulfide solid electrolyte materials obtained in Examples 1 to 3 and Comparative Example 1. XRD measurement was performed on the powder sample under an inert atmosphere and using CuKα rays. The result is shown in FIG. As shown in FIG. 8A, in Comparative Example 1, a single-phase sulfide solid electrolyte material was obtained. The peak positions are 2θ = 17.38 °, 20.18 °, 20.44 °, 23.56 °, 23.96 °, 24.93 °, 26.96 °, 29.07 °, 29.58. °, 31.71 °, 32.66 °, 33.39 °. That is, these peaks are considered to be peaks of the crystal phase A having high Li ion conductivity. Note that the above-described peak position may be back and forth within a range of ± 0.50 ° (in particular, ± 0.30 °). Further, in FIG. 8 (a), the peak of Li ₂ S was not confirmed.

Further, in FIG. 8 (a) ~ (d) , the diffraction intensity of the peak near 2 [Theta] = 29.58 ° and _{I A,} the intensity of the peak near 2 [Theta] = 27.33 ° and _{I B,} 29.78 ° If the intensity of the peak near was _{I c,} the value of I B / _{I a} and _I C / _{I a} were both 0. On the other hand, in FIGS. 8B to 8D, it was confirmed that there was a peak in the vicinity of 2θ = 26.10 °. If the intensity of this peak was I _D, the value of I D _/ I _A is now in the following Table 1. The peak positions of the crystal phase D were 2θ = 26.10 °, 29.86 °, 30.12 °, and 17.96 °.

As shown in Table 1, as an excess amount of P ₂ S ₅ increases, the value of I D _/ I _A that increase was confirmed. This indicates that the proportion of the crystal phase D, which is an impurity crystal phase, increases as the excessive amount of P ₂ S ₅ added increases. The relation between the value and the Li ion conductivity of the _I D / _{I A} in FIG. As shown in FIG. 9, the sulfide solid electrolyte material obtained in Example 3 was slightly inferior to the sulfide solid electrolyte material obtained in Comparative Example 1 from the viewpoint of Li ion conductivity, but Example 1 It was confirmed that the sulfide solid electrolyte material obtained in 2 exhibited a high Li ion conductivity equivalent to that of the sulfide solid electrolyte material obtained in Comparative Example 1.

(X-ray structural analysis)
The crystal structure of the sulfide solid electrolyte material obtained in Example 1 was identified by X-ray structural analysis. Based on the diffraction pattern obtained by XRD, a crystal system and a crystal group were determined by a direct method, and then a crystal structure was identified by a real space method. As a result, it was confirmed that the crystal structure as shown in FIG. That is, tetrahedron T ₁ (GeS ₄ tetrahedron and PS ₄ tetrahedron) and octahedron O (LiS ₆ octahedron) share a ridge, and tetrahedron T ₂ (PS ₄ tetrahedron) and octahedron O (LiS ₆ octahedron) was a crystal structure sharing a vertex. This crystal structure is considered to contribute to high Li conduction.

Claims (5)

M ₁ element, M ₂ element, P element and S element, and said M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca, Zn, and at least Li And M ₂ is at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb, and is at least tetravalent. The element has an element and has a peak at a position of 2θ = 29.58 ° ± 0.50 ° in X-ray diffraction measurement using CuKα ray, and the diffraction intensity of the peak at 2θ = 29.58 ° ± 0.50 ° Is a method for producing a sulfide solid electrolyte material in which the value of I _B / I _A is 1 or less, where IA is I _A and the diffraction intensity of the peak at 2θ = 27.33 ° ± 0.50 ° is I _B There,
An ion conductive material synthesizing step of synthesizing an amorphous ion conductive material using a raw material composition containing at least Li ₂ S, P ₂ S ₅ , a tetravalent element or a sulfide;
_A heating step of heating the ion conductive material so that the value of I _B / I _A is obtained;
The stoichiometric amount determined by the ratio of P ₂ S ₅ in the raw material composition from the general formula M _{1 (4-x)} M _{2 (1-x)} P _x S ₄ (x satisfies 0 <x <1). More than the argument,
The method for producing a sulfide solid electrolyte material, wherein a ratio of raw materials other than P ₂ S ₅ in the raw material composition is the same as a stoichiometric ratio obtained from the general formula. In the measurement of hydrogen sulfide generation using a sealed container (volume 1750 cc) filled with air, the ratio of P ₂ S ₅ in the raw material composition is the concentration of hydrogen sulfide generated from 50 mg of the sulfide solid electrolyte material (atmospheric exposure) 2. The method for producing a sulfide solid electrolyte material according to claim 1, wherein the ratio is 1 ppm after 60 minutes. The ratio of _P 2 _{S 5} in the raw material composition, the 2 [Theta] = 29.58 ° of the diffraction intensity of the peak of ± 0.50 ° and _{I A,} 2θ = 26.10 ° diffraction peak of ± 0.50 ° the strength when the I _D, production process of a sulfide solid electrolyte material according to claim 1 or claim 2, wherein the value of I D _/ I _a is a ratio of 1 or less. The ratio of P ₂ S ₅ in the raw material composition is large in the range of 5 wt% to 20 wt% with respect to the stoichiometric ratio obtained from the general formula. The method for producing a sulfide solid electrolyte material according to claim 3. Containing M ₁ element, M ₂ element, P element and S element,
The M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca, Zn, and contains at least Li,
M ₂ is at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb, and at least a tetravalent element. Including
It has a peak at 2θ = 29.58 ° ± 0.50 ° in an X-ray diffraction measurement using a CuKα ray, the diffraction intensity of the peak of the 2θ = 29.58 ° ± 0.50 ° and _{I A} , 2 [Theta] = 27.33 diffraction intensity of the peak of ° ± 0.50 ° when the _{I B,} the value of I B / _{I a} is 1 or less,
It has a peak at a position of 2θ = 26.10 ° ± 0.50 ° in X-ray diffraction measurement using CuKα ray, and the diffraction intensity of the peak at 2θ = 26.10 ° ± 0.50 ° is _ID. If the _sulfide solid electrolyte material, wherein the value of I D / _{I a} is in the range of 0.01 to 1.