JP5742562B2 - Solid electrolyte material-containing body and battery - Google Patents

Description

  The present invention relates to a solid electrolyte material-containing body that suppresses a decrease in ion conductivity of a sulfide solid electrolyte material due to the addition of a binder.

  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. In Non-Patent Document 2, Li ion conductor (sulfide solid electrolyte material) having a composition of Li _(4-x) Ge _(1-x) P _x S ₄ , styrene butadiene rubber (SBR), etc. It is described that a binder is added.

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) Taro Inada et al., “Silicone as a binder in composite electrolytes”, Journal of Power Sources, 119-121 (2003) 948-950

  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).

On the other hand, in Non-Patent Document 2, styrene butadiene rubber (SBR) is added to a Li ion conductor (sulfide solid electrolyte material) having a composition of Li _(4-x) Ge _(1-x) P _x S _4. It is described to do. However, in Non-Patent Document 2, the Li ion conductivity of the sulfide solid electrolyte material is reduced to 1/100 or less due to the addition of SBR. As described above, the sulfide solid electrolyte material has a problem that the ionic conductivity is greatly lowered by the added binder.

  This invention is made | formed in view of the said situation, and it aims at providing the solid electrolyte material containing body which suppressed the fall of the ionic conductivity of sulfide solid electrolyte material by addition of a binder. .

  In order to solve the above-mentioned problems, the present inventors have conducted intensive research. As a result, the above-described specific sulfide solid electrolyte material has not only high ion conductivity but also a double bond to the main chain such as SBR. It was found that the reactivity with a polymer having a low molecular weight is extremely low. The present invention has been made based on such knowledge.

That is, in the present invention, M ₁ element, M ₂ 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, 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 X-ray diffraction measurement using CuKα rays has a peak at 2θ = 29.58 ° ± 0.50 ° in the diffraction intensity of the peak of the 2θ = 29.58 ° ± 0.50 ° and _{I a, 2θ = 27.33 ° ±} 0 When a diffraction intensity of a peak at 50 ° is I _B , a sulfide solid electrolyte material having a value of I _B / I _A of less than 0.50 and a binder that is a polymer having a double bond in the main chain And a solid electrolyte material-containing body characterized by comprising:

  According to the present invention, since a sulfide solid electrolyte material having a high proportion of crystal phase having a peak around 2θ = 29.58 ° is used, a binder which is a polymer having a double bond in the main chain is added. Moreover, it can be set as the solid electrolyte material containing body which suppressed the fall of the ionic conductivity of sulfide solid electrolyte material by addition of a binder.

In the above invention, the value of the _I B / _{I A} is preferably 0.25 or less. This is because a ratio of a crystal phase having a peak around 2θ = 29.58 ° is high, and a sulfide solid electrolyte material having better ion conductivity can be obtained.

  In the above invention, the sulfide solid electrolyte material is obtained by 2θ = 17.38 °, 20.18 °, 20.44 °, 23.56 °, 23.96 ° in X-ray diffraction measurement using CuKα ray. 24.93 °, 26.96 °, 29.07 °, 29.58 °, 31.71 °, 32.66 °, 33.39 ° positions (note that these positions are ± 0.50 ° It may preferably have a peak in the range.

In the above-mentioned invention, the _{M 1} is Li, it is preferable that the _{M 2} is Ge and P. It is because it can be set as the sulfide solid electrolyte material with high Li ion conductivity.

In the above invention, the sulfide solid electrolyte material preferably has a composition of Li _(4-x) Ge _(1-x) P _x S ₄ (x satisfies 0 <x <1). It is because it can be set as the sulfide solid electrolyte material with high Li ion conductivity.

  In the said invention, it is preferable that said x satisfy | fills 0.5 <= x <= 0.8.

In the present invention, the octahedron O composed of the M ₁ element and the S element, the tetrahedron T ₁ composed of the M _2a element and the S element, and the tetrahedron composed of the M _2b element and the S element. and a T _2, the tetrahedron T ₁ and the octahedron O share a crest above tetrahedron T ₂ and the octahedron O contains mainly a crystalline structure that share vertices, the M ₁ is , Li, Na, K, Mg, Ca, Zn, and M _2a and M _2b are each independently P, Sb, Si, Ge, Sn, B, Al, Containing at least one sulfide solid electrolyte material selected from the group consisting of Ga, In, Ti, Zr, V, and Nb, and a binder that is a polymer having a double bond in the main chain. Solid electrolyte material containing body I will provide a.

According to the present invention, since the octahedron O, the tetrahedron T ₁ and the tetrahedron T ₂ use a sulfide solid electrolyte material having a predetermined crystal structure (three-dimensional structure), the polymer having a double bond in the main chain is used. Even if a certain binder is added, a solid electrolyte material-containing body can be obtained in which a decrease in ion conductivity of the sulfide solid electrolyte material due to the addition of the binder is suppressed.

In the invention, the octahedron O is a LiS ₆ octahedron in which the M ₁ is Li, and the tetrahedron T ₁ is a GeS ₄ tetrahedron and a PS ₄ tetrahedron in which the M _2a is Ge and P. , and the above tetrahedron _{T 2} are, it is preferable that the _{M 2b} is PS ₄ tetrahedron is P.

In the above invention, the sulfide solid electrolyte material 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 ° ± 0. the diffraction intensity of the peak of .50 ° and _{I a,} the diffraction intensity of the peak of 2θ = 27.33 ° ± 0.50 ° when the _{I B,} less than I B / _I value of _a 0.50 Preferably there is.

  In the said invention, it is preferable that the said binder is a styrene butadiene rubber (SBR).

  In the present invention, a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and an electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer In which at least one of the positive electrode active material layer, the negative electrode active material layer, and the electrolyte layer is the above-described solid electrolyte material-containing body.

  According to the present invention, a high-power battery can be obtained by using the above-described solid electrolyte material-containing body for at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer.

  In this invention, there exists an effect that the solid electrolyte material containing body which suppressed the fall of the ionic conductivity of sulfide solid electrolyte material by addition of a binder can be obtained.

It is a schematic sectional drawing which shows an example of the solid electrolyte material containing body of this invention. It is an X-ray diffraction spectrum explaining the difference between the sulfide solid electrolyte material of the present invention and a conventional sulfide solid electrolyte material. 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 a perspective view explaining an example of the crystal structure of the sulfide solid electrolyte material of this invention. It is a schematic sectional drawing which shows an example of the battery of this invention. 2 is an X-ray diffraction spectrum of a sulfide solid electrolyte material synthesized in Example 1 and Comparative Example 1. FIG. It is the result of the resistivity measurement of the mixture obtained in Example 1 and Comparative Example 1. 4 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 3. 2 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 1 and a comparative sample obtained in Comparative Production Example 1. FIG. 3 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 2 and a comparative sample obtained in Comparative Production Example 2. FIG. 4 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 3 and a comparative sample obtained in Comparative Production Example 3. FIG. 4 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 4 and a comparative sample obtained in Comparative Production Example 4. FIG. It is a measurement result of Li ion conductivity of the sulfide solid electrolyte material obtained in Production Examples 1 to 4 and the comparative sample obtained in Comparative Production Examples 1 to 4. It is a measurement result of Li ion conductivity of the sulfide solid electrolyte material obtained in Production Examples 1 to 3 and the comparative sample obtained in Comparative Production Examples 1 to 3. It is a X-ray-diffraction spectrum of the sample for reference obtained in Reference Examples 1-4. It is a measurement result of Li ion conductivity of the sample for reference obtained in Reference Examples 1-4. 7 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 5 and a comparative sample obtained in Comparative Production Example 5-1. 7 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 6 and a comparative sample obtained in Comparative Production Example 6. 7 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 7 and a comparative sample obtained in Comparative Production Example 7. FIG. 7 is an X-ray diffraction spectrum of a sulfide solid electrolyte material obtained in Production Example 5 and a comparative sample obtained in Comparative Production Examples 5-2 and 5-3. It is a Raman spectroscopy spectrum of the sample for a comparison obtained by comparative manufacture example 5-1 and comparative manufacture example 6. It is an X-ray diffraction spectrum of the sulfide solid electrolyte material obtained in Production Examples 8 to 10. It is an X-ray diffraction spectrum of the sulfide solid electrolyte material obtained in Production Examples 11-13.

  Hereinafter, the solid electrolyte material-containing body and battery of the present invention will be described in detail.

A. First, the solid electrolyte material-containing body of the present invention will be described. The solid electrolyte material-containing body of the present invention can be roughly divided into two embodiments. Therefore, the solid electrolyte material-containing body of the present invention will be described separately for the first embodiment and the second embodiment.

1. First Embodiment The solid electrolyte material-containing body of the first embodiment contains an M ₁ element, an M ₂ element, and an 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 M ₂ is at least one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, Nb, 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} , the two diffraction intensity of the peak of 2θ = 27.33 ° ± 0.50 ° when the _{I B,} and the sulfide solid electrolyte material value of I B / _{I a} is less than 0.50, in the main chain And a binder which is a polymer having a heavy bond. .

  According to the first embodiment, since a sulfide solid electrolyte material having a high proportion of crystal phase having a peak near 2θ = 29.58 ° is used, a binder which is a polymer having a double bond in the main chain is added. Even so, a solid electrolyte material-containing body in which a decrease in ion conductivity of the sulfide solid electrolyte material due to the addition of the binder can be suppressed. Further, since the sulfide solid electrolyte material having a high proportion of the crystal phase having a peak near 2θ = 29.58 ° has good ion conductivity, by using the solid electrolyte material-containing body of the first embodiment, A high output battery can be obtained.

FIG. 1 is a schematic cross-sectional view showing an example of the solid electrolyte material-containing body of the first embodiment. As shown in FIG. 1, the solid electrolyte material-containing body 10 contains the sulfide solid electrolyte material 1 described above and a binder 2 that is a polymer having a double bond in the main chain.
Hereinafter, the solid electrolyte material-containing body of the first embodiment will be described for each configuration.

(1) Sulfide solid electrolyte material The sulfide solid electrolyte material in the first embodiment contains an M ₁ element, an M ₂ element, and an S element, and the above M ₁ is Li, Na, K, Mg, Ca, Zn And 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, and has a peak at the position of 2θ = 29.58 ° ± 0.50 ° in the X-ray diffraction measurement using CuKα ray, and the diffraction intensity of the peak at 2θ = 29.58 ° ± 0.50 ° was a _{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 less than 0.50.

FIG. 2 is an X-ray diffraction spectrum for explaining the difference between the sulfide solid electrolyte material in the first embodiment and the conventional sulfide solid electrolyte material. Note that the two sulfide solid electrolyte materials in FIG. 2 both have a composition of Li _3.25 Ge _0.25 P _0.75 S ₄ . The sulfide solid electrolyte material of the present invention in FIG. 2 has a peak at a position of 2θ = 29.58 ° ± 0.50 ° and a position of 2θ = 27.33 ° ± 0.50 °. Also, the conventional sulfide solid electrolyte material in FIG. 2 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 crystalline phases exhibiting ionic conductivity, but there are differences in ionic conductivity. As shown in the production examples described later, the crystal phase A is considered to have significantly higher ionic 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 ion conductivity cannot be reduced, and the ion conductivity cannot be sufficiently increased. On the other hand, in the first embodiment, since the crystalline phase A having high ion conductivity can be positively precipitated by the method for producing a sulfide solid electrolyte material described later, the sulfide having high ion conductivity. A solid electrolyte material can be obtained. Moreover, as described in the examples described later, the crystal phase A is less reactive with the double bond contained in the binder than the crystal phase B. The reason is considered that the crystal phase A has higher chemical stability than the crystal phase B.

Further, in the first embodiment, in order to distinguish it from conventional sulfide solid electrolyte material, 2 [Theta] = 29.58 diffraction intensity of the peak in the vicinity ° and I _A, the diffraction intensity of the peak near 2 [Theta] = 27.33 ° Is defined as I _B, and the value of I _B / I _A is defined to be less than 0.50. Incidentally, I B _/ I sulfide solid electrolyte material value is less than 0.50 _A, the conventional synthetic methods would not be able to obtain. From the viewpoint of ion conductivity, the sulfide solid electrolyte material in the first embodiment preferably has a high proportion of the crystal phase A having high ion conductivity. Therefore, the value of I _B / I _A is preferably smaller, specifically 0.45 or less, more preferably 0.25 or less, and further preferably 0.15 or less. It is preferably 0.07 or less. Further, the value of I _B / I _A is preferably 0. In other words, the sulfide solid electrolyte material in the first embodiment preferably does not have a peak around 2θ = 27.33 °, which is the peak of the crystal phase B.

  The sulfide solid electrolyte material in the first embodiment 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 ion conductivity. Here, 2θ = 29.58 ° in the first embodiment is an actual measurement value obtained in a manufacturing example described later, the crystal lattice slightly changes depending on the material composition and the like, and the peak position is 2θ = 29.58 °. May be slightly different from. Therefore, in the first embodiment, 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 near 2θ = 27.33 ° is one of the peaks of the crystal phase B having low ion conductivity as described above. Here, 2θ = 27.33 ° in the first embodiment is an actual measurement value obtained in a manufacturing example described later, the crystal lattice slightly changes depending on the material composition and the like, and the peak position is 2θ = 27.33 °. May be slightly different from. Therefore, in the first embodiment, 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 °.

In addition, the sulfide solid electrolyte material in the first embodiment contains M ₁ element, M ₂ element and S element. M ₁ is preferably a monovalent or divalent element. Examples of M ₁ include at least one selected from the group consisting of Li, Na, K, Mg, Ca, and Zn. All of these elements function as conductive ions. Among these, in the first embodiment, it is preferable that M ₁ is Li. It is because it can be set as the sulfide solid electrolyte material useful for a lithium battery. The M ₁ is a monovalent element (for example, Li, Na, K), and a part thereof may be substituted with a divalent or higher element (for example, Mg, Ca, Zn). Thereby, a monovalent element becomes easy to move and ion conductivity improves.

On the other hand, M ₂ is preferably a trivalent, tetravalent or pentavalent element. Examples of M ₂ include one selected from the group consisting of P, Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. Among these, in the first embodiment, the M ₂ is preferably at least one selected from the group consisting of P, Ge, Al, Zr, Sn, and B, and is at least one of P and Ge. More preferred. Further, the M ₂ may be two or more elements.

In the sulfide solid electrolyte material in the first embodiment, it is preferable that the M ₁ contains at least Li and the M ₂ contains a tetravalent element. Further, the sulfide solid electrolyte material preferably has a composition of M _{1 (4-x)} M _{2 (1-x)} P _x S ₄ (x satisfies 0 <x <1).

In the manufacturing examples described later, actually synthesized a sulfide solid electrolyte material LiGePS system, subjected to X-ray diffraction measurement of the sample obtained, to confirm that I B _/ I _A is equal to or less than a predetermined value ing. In this LiGePS-based sulfide solid electrolyte material, in the above general formula, the M ₁ element corresponds to the Li element, and the M ₂ element corresponds to the Ge element and the P element. On the other hand, the sulfide solid electrolyte material in the first embodiment usually has a specific crystal structure described in the second embodiment described later. It is presumed that the M ₁ element and the M ₂ element can take a similar crystal structure in the LiGePS-based sulfide solid electrolyte material in any combination thereof. Therefore, it is considered that a sulfide solid electrolyte material having good ion conductivity can be obtained in any combination of M ₁ element and M ₂ element. In addition, since the position of the peak of X-ray diffraction depends on the crystal structure, it is similar if the sulfide solid electrolyte material has the above crystal structure, regardless of the types of the M ₁ element and M ₂ element. It is considered that an XRD pattern is obtained.

Moreover, it is preferable that the sulfide solid electrolyte material in a 1st embodiment contains Li element, Ge element, P element, and S element. Furthermore, the composition of the sulfide solid electrolyte material LiGePS system, but is not particularly limited as long as the composition can be obtained the value of a given _{I B / I A, Li (} 4-x) Ge (1 _-X) It is preferable that the composition is P _x S ₄ (x satisfies 0 <x <1). It is because it can be set as the sulfide solid electrolyte material with high Li ion conductivity. _Here, the composition of _{Li (4-x) Ge (} 1-x) P x S 4 corresponds to the composition of the solid solution of _Li 3 PS ₄ and _Li 4 GeS _4. That is, this composition corresponds to the composition on the tie line of Li ₃ PS ₄ and Li ₄ GeS ₄ . Note that both Li ₃ PS ₄ and Li ₄ GeS ₄ correspond to the ortho composition and have an advantage of high chemical stability. The sulfide solid electrolyte material having such a composition of Li _(4-x) Ge _(1-x) P _x S ₄ has been conventionally known as thiolithicone, and the sulfide solid electrolyte material in the first embodiment is The composition may be the same as that of conventional thiolysicon. However, as described above, the ratio of the crystal phase contained in the sulfide solid electrolyte material in the first embodiment is completely different from the ratio of the conventional crystal phase.

_Also, x in _{Li (4-x) Ge (} 1-x) P x S 4 is not particularly limited as long as the value can be obtained the value of a given _I B / _{I A,} e.g. 0.4 ≦ x is preferable, 0.5 ≦ x is more preferable, and 0.6 ≦ x is more preferable. On the other hand, the x preferably satisfies x ≦ 0.8, and more preferably satisfies x ≦ 0.75. This is because the value of I _B / I _A can be further reduced by setting the range of such x. Thereby, it can be set as the sulfide solid electrolyte material with further favorable Li ion conductivity. Also, the sulfide solid electrolyte material in the first _embodiment, Li 2 _S, is preferably made using a P 2 _{S 5} and GeS _2.

The sulfide solid electrolyte material in the first embodiment is usually a crystalline sulfide solid electrolyte material. The sulfide solid electrolyte material in the first embodiment preferably has high ionic conductivity, and the ionic conductivity of the sulfide solid electrolyte material at 25 ° C. is 1.0 × 10 ⁻³ S / cm or more. It is preferably 2.3 × 10 ⁻³ S / cm or more. Moreover, the shape of the sulfide solid electrolyte material in the first embodiment is not particularly limited, and examples thereof include powder. 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.

(2) Binder Next, the binder in the first embodiment will be described. The binder in the first embodiment is a polymer having a double bond in the main chain, and binds the above-described sulfide solid electrolyte material. In addition, this polymer usually contains at least carbon and hydrogen, and if necessary, part or all of the hydrogen bonded to carbon may be substituted with halogen such as fluorine. Specific examples of such polymers include styrene butadiene rubber (SBR), styrene butadiene styrene block copolymer (SBS), styrene ethylene butylene styrene block copolymer (SEBS), and butyl rubber (isobutylene isoprene rubber, IIR). Butadiene rubber (BR), isoprene rubber (IR) and the like.

  The number average molecular weight of the polymer is, for example, preferably in the range of 1,000 to 700,000, more preferably in the range of 10,000 to 100,000, and 30,000 to 80. More preferably, it is within the range of 1,000. If the molecular weight is too small, the desired flexibility may not be obtained. If the molecular weight is too large, the solubility in the solvent may be reduced, and the desired dispersion state may not be obtained. is there.

  The polymer is preferably a hydrogenated polymer. This is because the reactivity with the sulfide solid electrolyte material can be controlled low. Here, the hydrogenated polymer means a polymer obtained by removing unsaturated bonds (for example, a double bond in the main chain) in the polymer by hydrogenation. Thus, by removing the unsaturated bond, the reactivity with the sulfide solid electrolyte material can be controlled to be low. Further, by removing the unsaturated bond, the polymer becomes difficult to be plastically deformed and is easily elastically deformed. Thereby, there is an advantage that the molecular chain of the polymer is hardly broken and the binding property is easily maintained. Specific examples of the hydrogenated polymer include hydrogenated products of the above-described polymers.

  As a hydrogenation rate of a hydrogenated polymer, it is preferable that it is 90% or more, for example, and it is more preferable that it is 95% or more. This is because if the hydrogenation rate of the hydrogenated polymer is too low, the unsaturated bonds in the polymer are not removed so much that the advantages of the hydrogenated polymer may not arise.

  Moreover, since a polar solvent may react with the sulfide solid electrolyte material mentioned above at the time of preparation of a solid electrolyte material containing body, it is assumed that a nonpolar solvent is used. Therefore, the polymer is preferably one that is soluble in a nonpolar solvent such as a saturated hydrocarbon solvent, an aromatic hydrocarbon solvent, a fluorine solvent, or a chlorine solvent.

(3) Solid electrolyte material-containing body The solid electrolyte material-containing body of the first embodiment contains the sulfide solid electrolyte material and the binder described above. The shape of the solid electrolyte material-containing body is not particularly limited, and examples thereof include powders, layers, and pellets.

  For example, when the solid electrolyte material-containing body of the first embodiment is used as an active material layer of a battery, the solid electrolyte material-containing body contains at least an active material in addition to a sulfide solid electrolyte material and a binder. In this case, the ratio of the sulfide solid electrolyte material in the solid electrolyte material-containing body is not particularly limited, but is preferably in the range of 0.1 wt% to 80 wt%, for example, 1 wt% It is more preferably in the range of ˜80% by weight, and further preferably in the range of 10% by weight to 50% by weight. On the other hand, when the solid electrolyte material-containing body of the first embodiment is used as a solid electrolyte layer of a battery, the solid electrolyte material-containing body contains a sulfide solid electrolyte material and a binder, and has no active material. In this case, the ratio of the sulfide solid electrolyte material in the solid electrolyte material-containing body is not particularly limited, but is preferably 10% by weight or more, more preferably 50% by weight or more, More preferably, it is 80% by weight or more.

  The ratio of the binder in the solid electrolyte material-containing body is not particularly limited, but it is preferably smaller from the viewpoint of ensuring ion conductivity and electronic conductivity. Specifically, it is preferably in the range of 0.01% by weight to 30% by weight, and more preferably in the range of 0.1% by weight to 10% by weight. If the proportion of the binder is too small, it may be difficult to bind the sulfide solid electrolyte material sufficiently, and if the proportion of the binder is too large, the ion conductivity and the electronic conductivity will be inhibited. Because there is a possibility of doing.

  In addition, the solid electrolyte material-containing body of the first embodiment can be used for any application that requires ion conductivity. Especially, it is preferable that the solid electrolyte material containing body of a 1st embodiment is what is used for a battery. This is because it can greatly contribute to the high output of the battery. Further, the solid electrolyte material-containing body of the first embodiment may have the characteristics of the second embodiment or other embodiments described later. Further, the method for producing the solid electrolyte material-containing body of the first embodiment is not particularly limited, and the sulfide solid electrolyte material and the binder may be simply mixed, or both may be mixed in a solvent. Also good. Moreover, when using the solid electrolyte material containing body of a 1st embodiment as an active material layer, you may further add an active material, a electrically conductive material, etc. at the time of manufacture of a solid electrolyte material containing body.

(4) Manufacturing method of sulfide solid electrolyte material Next, the manufacturing method of the sulfide solid electrolyte material in a 1st embodiment is demonstrated. The method for producing the sulfide solid electrolyte material is not particularly limited as long as it is a method capable of obtaining the above-described sulfide solid electrolyte material. Here, two manufacturing methods will be described as a first manufacturing method and a second manufacturing method.

(I) First Manufacturing Method The first manufacturing method includes M ₁ element (M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca, Zn), M ₂ element (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 a raw material composition containing S element An ion conductive material synthesizing step for synthesizing a crystalline ion conductive material, a crystallinity lowering step for reducing the crystallinity of the ion conductive material by mechanical milling, and an ion conduction having a reduced crystallinity. By heating the crystalline material, it has a peak at the position of 2θ = 29.58 ° ± 0.50 ° in the X-ray diffraction measurement using CuKα ray, and the above 2θ = 29.58 ° ± 0.50 ° the diffraction intensity of the peak and _{I a,} 2 = 27.33 The diffraction intensity of the peak of ° ± 0.50 ° when the _{I B,} having a heating process of the value of I B / _{I A} to obtain a sulfide solid electrolyte material is less than 0.50, the It is characterized by this.

  According to the first manufacturing method, in addition to the ion conductive material synthesis step, a sulfide solid having a high proportion of crystal phase having a peak near 2θ = 29.58 ° by performing the crystallinity lowering step and the heating step. An electrolyte material can be obtained. Therefore, a sulfide solid electrolyte material having good ion conductivity can be obtained.

FIG. 3 is an explanatory view showing an example of the first manufacturing method. In FIG. 3, first, a raw material composition is prepared by mixing Li ₂ S, P ₂ S ₅ and GeS ₂ . At this time, in order to prevent the raw material composition from being deteriorated by moisture in the air, it is preferable to prepare the raw material composition in an inert gas atmosphere. Next, the raw material composition is heated in a vacuum to obtain a crystalline ion conductive material by a solid phase reaction. Here, the ion conductive material in the first production method refers to a material before performing a crystallinity lowering step and a heating step described later. This ion conductive material is the same material as the conventional sulfide solid electrolyte material, but in order to distinguish it from the sulfide solid electrolyte material in the first embodiment, it will be referred to as an ion conductive material. Next, the obtained ion conductive material is pulverized by a vibration mill to reduce the crystallinity of the ion conductive material. Next, the ion conductive material having lowered crystallinity is heated again to improve the crystallinity, thereby obtaining a sulfide solid electrolyte material.

In the first production method, a sulfide solid electrolyte material having a high proportion of crystal phase having a peak near 2θ = 29.58 ° can be obtained. The reason will be described below. In the first manufacturing method, after the crystalline ion conductive material is synthesized, a process for reducing the crystallinity of the ion conductive material is performed. As a result, the crystal phase A with high 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 made less than 0.50, which was impossible in the past. The reason why the crystal phase A tends to precipitate due to the decrease in crystallinity of the ion conductive material is not completely clear, but the solid solution region in the ion conductive material is changed by mechanical milling, and the crystal phase A is There is a possibility that the environment has changed from an environment in which precipitation is difficult to an environment in which precipitation is likely to occur.
Hereinafter, a 1st manufacturing method is demonstrated for every process.

(Ion conductive material synthesis process)
First, the ion conductive material synthesis step in the first production method will be described. The ion conductive material synthesis step in the first production method is a step of synthesizing a crystalline ion conductive material using a raw material composition containing an M ₁ element, an M ₂ element, and an S element.

The raw material composition in the first production method is not particularly limited as long as it contains an M ₁ element, an M ₂ element, and an S element. Note that the M ₁ element and M ₂ element in the raw material composition is similar to the matters described in the "A. solid electrolyte material-containing bodies". Further, each of the M ₁ element and the M ₂ element contained in the raw material composition may be a sulfide or a simple substance. As an example of a raw material _composition, there can be mentioned those containing Li 2 _S, P 2 _{S 5} and GeS _2.

  In addition, the composition of the raw material composition is not particularly limited as long as it can finally obtain a desired sulfide solid electrolyte material. Especially, it is preferable that a raw material composition is a composition which can synthesize | combine the ion conductive material which has a peak of 2 (theta) = 29.58 degree vicinity. If the ion conductive material has a peak around 2θ = 29.58 °, when a sulfide solid electrolyte material is obtained through a crystallinity lowering step and a heating step described later, 2θ = around 29.58 °. This is because the peak of is likely to occur.

Furthermore, the raw material composition has a composition capable of synthesizing an ion conductive material having a composition of Li _(4-x) Ge _(1-x) P _x S ₄ (x satisfies 0 <x <1). It is preferable. This is because a sulfide solid electrolyte material having high Li ion conductivity can be obtained. As described above, the composition of Li _(4-x) Ge _(1-x) P _x S ₄ corresponds to the composition of the solid solution of Li ₃ PS ₄ and Li ₄ GeS ₄ . Here, considering the case where the raw material composition contains Li ₂ S, P ₂ S ₅ and GeS ₂ , the ratio of Li ₂ S and P ₂ S ₅ for obtaining Li ₃ PS ₄ is on a molar basis, Li ₂ S: P ₂ S ₅ = 75: 25. On the other hand, the ratio of Li ₂ S and GeS ₂ for obtaining Li ₄ GeS ₄ is Li ₂ S: GeS ₂ = 66.7: 33.3 on a molar basis. Therefore, it is preferable to determine the amount of Li ₂ S, P ₂ S ₅ and GeS ₂ used in consideration of these ratios. Further, the preferable range of x is the same as the content described in the above “A. Solid electrolyte material-containing body”.

  In the first production method, a crystalline ion conductive material is synthesized from the raw material composition. The method for synthesizing the ion conductive material is not particularly limited as long as it is a method capable of obtaining a crystalline ion conductive material, and examples thereof include a solid phase method. The solid phase method is a method of synthesizing a target sample 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.

(Crystallinity reduction process)
Next, the crystallinity lowering step in the first production method will be described. The crystallinity reduction step in the first production method is a step of reducing the crystallinity of the ion conductive material by mechanical milling. In the first production method, once the crystallinity of the crystalline ion conductive material is lowered, a crystal phase A having high ion conductivity (a crystal phase having a peak near 2θ = 29.58 °) is precipitated. Easy environment.

  Mechanical milling is a method of crushing a sample while applying mechanical energy. In the first production method, the crystallinity of the ion conductive material can be lowered by applying mechanical energy to the crystalline ion conductive material. Examples of such mechanical milling include a vibration mill, a ball mill, a turbo mill, a mechano-fusion, and a disk mill. Among these, a vibration mill is preferable. The conditions of the vibration mill are not particularly limited as long as the crystallinity of the ion conductive material can be lowered. The vibration amplitude of the vibration mill is, for example, preferably in the range of 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 sample of the vibration mill is, for example, preferably in the range of 1% by volume to 80% by volume, more preferably in the range of 5% by volume to 60% by volume, and particularly preferably in the range of 10% by volume to 50% by volume. Moreover, it is preferable to use a vibrator (for example, an alumina vibrator) for the vibration mill.

  In the first production method, the crystallinity of the ion conductive material is preferably lowered so that a crystal phase having a peak near 2θ = 29.58 ° is likely to precipitate.

(Heating process)
Next, the heating process in the first manufacturing method will be described. The heating step in the first production method has a peak at a position of 2θ = 29.58 ° ± 0.50 ° in the X-ray diffraction measurement using CuKα ray by heating the ion conductive material having reduced crystallinity. the a, a diffraction intensity of the peak of the 2θ = 29.58 ° ± 0.50 ° and _{I a,} the diffraction intensity of the peak of 2θ = 27.33 ° ± 0.50 ° when the _{I B,} This is a step of obtaining a sulfide solid electrolyte material having a value of I _B / I _A of less than 0.50.

In the first production method, the crystallinity is improved by heating the ion conductive material having lowered crystallinity. By performing this heating, the crystal phase A having high ion conductivity (a crystal phase having a peak around 2θ = 29.58 °) can be positively precipitated, and the value of I _B / I _A is It could be less than 0.50, which was impossible.

  The heating temperature in the first production method is not particularly limited as long as it is a temperature at which a desired sulfide solid electrolyte material can be obtained, but a crystal phase A (a crystal having a peak around 2θ = 29.58 °). The temperature is preferably equal to or higher than the crystallization temperature of the phase. 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. Moreover, it is preferable to perform the heating in a 1st manufacturing method in inert gas atmosphere or in a vacuum from a viewpoint of preventing oxidation. In addition, the sulfide solid electrolyte material obtained by the first production method is the same as that described in the above “A. Solid electrolyte material-containing body”, so description thereof is omitted here.

(Ii) Second production method The second production method comprises M ₁ element (M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca, Zn), M ₂ element (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 a raw material composition containing S element Using an ion conductive material synthesis step of synthesizing an amorphous ion conductive material by mechanical milling, and heating the amorphous ion conductive material, X-rays using CuKα rays are used. It has a peak at 2θ = 29.58 ° ± 0.50 ° in diffraction measurement, the diffraction intensity of the peak of the 2θ = 29.58 ° ± 0.50 ° and _{I a, 2θ} = 27.33 ° If the diffraction intensity peaks of ± 0.50 ° was _{I B} To, those characterized by having a heating process of the value of I B _/ I _A to obtain a sulfide solid electrolyte material is less than 0.50, a.

  According to the second production method, a sulfide having a high ratio of crystal phase having a peak near 2θ = 29.58 ° is obtained by performing amorphization in an ion conductive material synthesis step and then performing a heating step. A solid electrolyte material can be obtained. Therefore, a sulfide solid electrolyte material having good ion conductivity can be obtained. Moreover, since the 2nd manufacturing method can reduce the number of processes compared with the 1st manufacturing method mentioned above, there exists an advantage that a yield improves.

FIG. 4 is an explanatory view showing an example of the second manufacturing method. In FIG. 4, first, a raw material composition is prepared by mixing Li ₂ S, P ₂ S ₅ and GeS ₂ . At this time, in order to prevent the raw material composition from being deteriorated by moisture in the air, it is preferable to prepare the raw material composition in an inert gas atmosphere. Next, the raw material composition is ball milled 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 the second production method, a sulfide solid electrolyte material having a high proportion of crystal phase having a peak near 2θ = 29.58 ° can be obtained. The reason for this is as described above. Is omitted.
Hereinafter, a 2nd manufacturing method is demonstrated for every process.

(Ion conductive material synthesis process)
First, the ion conductive material synthesis step in the second production method will be described. The ion conductive material synthesis step in the second manufacturing method is a step of synthesizing an amorphous ion conductive material by mechanical milling using a raw material composition containing M ₁ element, M ₂ element and S element. It is.

Since the raw material composition in the second manufacturing method is the same as the raw material composition in the first manufacturing method described above, description thereof is omitted here. In addition, the composition of the raw material composition is not particularly limited as long as it can finally obtain a desired sulfide solid electrolyte material. Above all, if the raw material composition contains a P ₂ S _5, the composition of the raw material composition is preferably P ₂ S ₅ is a synthetic possible compositions ion conductive material does not remain. This is because if P ₂ S ₅ remains, P ₂ S ₅ is melted in the subsequent heating step, which may make it difficult to precipitate the crystal phase A having high ion conductivity. Since the melting point of P ₂ S ₅ is as low as about 270 ° C., if it remains, melting occurs in the heating process. Whether or not P ₂ S ₅ remains in the obtained ion conductive material can be confirmed by, for example, Raman spectroscopic measurement.

  Mechanical milling is a method of pulverizing a sample while applying mechanical energy. In the second production method, an amorphous ion conductive material is 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. Among these, a ball mill is preferable, and a planetary ball mill is particularly preferable.

  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.

(Heating process)
The heating step in the second manufacturing method is a peak at a position of 2θ = 29.58 ° ± 0.50 ° in the X-ray diffraction measurement using CuKα ray by heating the amorphous ion conductive material. the a, a diffraction intensity of the peak of the 2θ = 29.58 ° ± 0.50 ° and _{I a,} the diffraction intensity of the peak of 2θ = 27.33 ° ± 0.50 ° when the _{I B,} This is a step of obtaining a sulfide solid electrolyte material having a value of I _B / I _A of less than 0.50. In addition, about a heating process, since it is the same as that of the heating process in the 1st manufacturing method mentioned above, description here is abbreviate | omitted.

2. Second Embodiment Next, a second embodiment of the solid electrolyte material-containing body of the present invention will be described. The solid electrolyte material-containing body of the second embodiment is composed of octahedron O composed of M ₁ element and S element, tetrahedron T ₁ composed of M _2a element and S element, and M _2b element and S element. and a tetrahedron T ₂ composed, the tetrahedron T ₁ and the octahedron O share a crest above tetrahedron T ₂ and the octahedron O contains mainly a crystalline structure that share vertices , M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca, Zn, and M _2a and M _2b are each independently P, Sb, Si, Ge, Sn. , B, Al, Ga, In, Ti, Zr, V, Nb, at least one sulfide solid electrolyte material selected from the group consisting of, and a binder that is a polymer having a double bond in the main chain; It is characterized by containing is there.

According to the second embodiment, the octahedron O, the tetrahedron T ₁ and the tetrahedron T ₂ use a sulfide solid electrolyte material having a predetermined crystal structure (three-dimensional structure), and thus have a double bond in the main chain. Even if a binder which is a polymer is added, a solid electrolyte material-containing body in which a decrease in ion conductivity of the sulfide solid electrolyte material due to the addition of the binder can be suppressed. Moreover, since the sulfide solid electrolyte material which has the said crystal structure as a main body has favorable ion conductivity, a high output battery can be obtained by using the solid electrolyte material containing body of a 2nd embodiment. This crystal structure is considered to correspond to the structure of crystal phase A described above. Moreover, it is thought that high ion conductivity is exhibited because a metal ion (for example, Li ion) conducts in the space part of this crystal structure.

(1) Sulfide solid electrolyte material The sulfide solid electrolyte material in the second embodiment includes an octahedron O composed of an M ₁ element and an S element, and a tetrahedron T ₁ composed of an M _2a element and an S element. And tetrahedron T ₂ composed of M _2b element and S element, the tetrahedron T ₁ and octahedron O share a ridge, and the tetrahedron T ₂ and octahedron O share a vertex. The M ₁ is at least one selected from the group consisting of Li, Na, K, Mg, Ca, Zn, and the M _2a and M _2b are each independently P , Sb, Si, Ge, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb.

FIG. 5 is a perspective view for explaining an example of the crystal structure of the sulfide solid electrolyte material in the second embodiment. In the crystal structure shown in FIG. 5, 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 in the second embodiment is characterized mainly by containing the 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. This is because a sulfide solid electrolyte material having high ion conductivity can be obtained. 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. In particular, the sulfide solid electrolyte material in the second embodiment is preferably a single-phase material having the above crystal structure. This is because the ion conductivity can be made extremely high.

Since the M ₁ element, M ₂ element (M _2a element, M _2b element) and other matters in the second embodiment are the same as those in the first embodiment described above, description thereof is omitted here. In addition, the sulfide solid electrolyte material in the second embodiment may have characteristics of other embodiments described later.

(2) Binder Since the binder in the second embodiment is the same as that in the first embodiment described above, description thereof is omitted here.

(3) Solid electrolyte material containing body The solid electrolyte material containing body of the second embodiment contains the sulfide solid electrolyte material and the binder described above. Since the solid electrolyte material-containing body of the second embodiment is the same as that of the first embodiment described above, description thereof is omitted here.

(4) Method for Producing Sulfide Solid Electrolyte Material The method for producing the sulfide solid electrolyte material in the second embodiment is not particularly limited as long as it is a method capable of obtaining the sulfide solid electrolyte material described above. Since it is the same as that of the 1st manufacturing method and the 2nd manufacturing method which were described in the 1st embodiment mentioned above, description here is abbreviate | omitted.

3. Other Embodiments The solid electrolyte material-containing body of the present invention may be the following embodiments. That is, the solid electrolyte material-containing body of the present invention contains M ₁ element, M ₂ element, and S element, and M ₁ is at least selected from the group consisting of Li, Na, K, Mg, Ca, and Zn. 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 uses CuKα rays. has a peak at 2θ = 29.58 ° ± 0.50 ° in an X-ray diffraction measurement had a diffraction intensity of the peak of the 2θ = 29.58 ° ± 0.50 ° and _{I a,} 2 [Theta] = 29 When the diffraction intensity of the peak at .78 ° ± 0.50 ° is I _C , a sulfide solid electrolyte material having a value of I _C / I _A of 0.20 or less and a double bond in the main chain It may be characterized by containing a binder that is a polymer. .

  According to the above embodiment, since a sulfide solid electrolyte material having a high proportion of crystal phase having a peak near 2θ = 29.58 ° is used, a binder which is a polymer having a double bond in the main chain is added. However, it can be set as the solid electrolyte material containing body which suppressed the ionic conductivity fall of the sulfide solid electrolyte material by addition of a binder. On the other hand, the crystal phase B having low ion conductivity has a peak in the vicinity of 2θ = 29.78 ° in addition to the vicinity of 2θ = 27.33 °, as shown in FIG. 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 °.

(1) sulfide solid electrolyte material in the sulfide solid electrolyte material above embodiments, contain _{M 1} element, _{M 2} element and S elements, said _{M 1} is Li, Na, K, Mg, Ca, and Zn 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 has a peak at a position of 2θ = 29.58 ° ± 0.50 ° in the X-ray diffraction measurement using CuKα ray, and the diffraction intensity of the peak at 2θ = 29.58 ° ± 0.50 ° and I _a, the diffraction intensity of the peak of 2θ = 29.78 ° ± 0.50 ° when the _{I C,} the value of I C / _{I a} is 0.20 or less.

In the above embodiment, in order to distinguish it from conventional sulfide solid electrolyte material, the diffraction intensity of the peak near 2 [Theta] = 29.58 ° and I _A, the diffraction intensity of the peak near 2 [Theta] = 29.78 ° I _C, and the value of I _C / I _A is specified to be 0.20 or less. Incidentally, the sulfide solid electrolyte material value of 0.20 or less of I C _/ I _A is a conventional synthetic method considered can not be obtained. From the viewpoint of ion conductivity, the sulfide solid electrolyte material in the above embodiment preferably has a high proportion of crystal phase A having high ion conductivity. For this reason, the value of I _C / I _A is preferably smaller, specifically preferably 0.15 or less, more preferably 0.10 or less, and further preferably 0.07 or less. preferable. The value of I _C / I _A is preferably 0. In other words, the sulfide solid electrolyte material in the above embodiment preferably does not have a peak around 2θ = 29.78 °, which is the peak of the crystal phase B.

Note that the M ₁ element, M ₂ element and other matters in the embodiment is the same as the first embodiment described above, the description thereof is omitted here.

(2) Binder Since the binder in the above embodiment is the same as that in the first embodiment described above, description thereof is omitted here.

(3) Solid electrolyte material containing body The solid electrolyte material containing body of the said embodiment contains the sulfide solid electrolyte material and binder mentioned above. About the solid electrolyte material containing body of the said embodiment, since it is the same as that of the 1st embodiment mentioned above, description here is abbreviate | omitted.

(4) Method for Producing Sulfide Solid Electrolyte Material The method for producing the sulfide solid electrolyte material in the above embodiment is not particularly limited as long as it is a method capable of obtaining the sulfide solid electrolyte material described above. Since it is the same as the 1st manufacturing method and the 2nd manufacturing method which were described in the 1st embodiment mentioned above, description here is abbreviate | omitted.

B. Battery Next, the battery of the present invention will be described. The battery of the present invention includes a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, an electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer, In which at least one of the positive electrode active material layer, the negative electrode active material layer, and the electrolyte layer is the above-described solid electrolyte material-containing body.

  According to the present invention, a high-power battery can be obtained by using the above-described solid electrolyte material-containing body for at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer.

FIG. 6 is a schematic cross-sectional view showing an example of the battery of the present invention. The battery 20 in FIG. 6 was formed between the positive electrode active material layer 11 containing the positive electrode active material, the negative electrode active material layer 12 containing the negative electrode active material, and the positive electrode active material layer 11 and the negative electrode active material layer 12. An electrolyte layer 13, a positive electrode current collector 14 that collects current from the positive electrode active material layer 11, a negative electrode current collector 15 that collects current from the negative electrode active material layer 12, and a battery case 6 that houses these members. It is what you have. In the present invention, at least one of the positive electrode active material layer 11, the negative electrode active material layer 12, and the electrolyte layer 13 is a solid electrolyte material-containing body described in the above “A. Solid electrolyte material-containing body”. To do.
Hereinafter, the battery of this invention is demonstrated for every structure.

1. Electrolyte Layer First, the electrolyte layer in the present invention will be described. The electrolyte layer in the present invention is a layer formed between the positive electrode active material layer and the negative electrode active material layer. The electrolyte layer is not particularly limited as long as it is a layer capable of conducting ions, but is preferably a solid electrolyte layer made of a solid electrolyte material. This is because a battery with higher safety can be obtained as compared with a battery using an electrolytic solution. Furthermore, in this invention, it is preferable that a solid electrolyte layer is a solid electrolyte material containing body mentioned above. The thickness of the solid electrolyte layer is, for example, preferably in the range of 0.1 μm to 1000 μm, and more preferably in the range of 0.1 μm to 300 μm. Moreover, as a formation method of a solid electrolyte layer, the method etc. which compression-mold a solid electrolyte material can be mentioned, for example.

Further, the electrolyte layer in the present invention may be a layer composed of an electrolytic solution. When the electrolytic solution is used, it is necessary to further consider safety compared to the case where the solid electrolyte layer is used, but a battery with higher output can be obtained. In this case, at least one of the positive electrode active material layer and the negative electrode active material layer is usually a solid electrolyte material-containing body. The electrolytic solution used for the lithium battery usually contains a lithium salt and an organic solvent (nonaqueous solvent). Examples of the lithium salt include inorganic lithium salts such as LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , and LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiC An organic lithium salt such as (CF ₃ SO ₂ ) ₃ can be used. Examples of the organic solvent include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), butylene carbonate (BC), and the like.

2. Next, the positive electrode active material layer in the present invention will be described. The positive electrode active material layer in the present invention is a layer containing at least a positive electrode active material, and may contain at least one of a solid electrolyte material, a conductive material and a binder as necessary. In particular, in the present invention, the positive electrode active material layer is preferably the above-described solid electrolyte material-containing body. This is because a positive electrode active material layer having high ion conductivity can be obtained. As the positive electrode active material used in a lithium battery, for example _{LiCoO 2, LiMnO 2, Li 2} NiMn 3 O 8, LiVO 2, LiCrO 2, LiFePO 4, LiCoPO 4, LiNiO 2, LiNi 1/3 Co 1/3 Mn _1/3 O _{2 and the} like can be mentioned.

  The positive electrode active material layer in the present invention may further contain a conductive material. By adding a conductive material, the conductivity of the positive electrode active material layer can be improved. Examples of the conductive material include acetylene black, ketjen black, and carbon fiber. The positive electrode active material layer may contain a binder. Examples of the type of binder include fluorine-containing binders such as polytetrafluoroethylene (PTFE). Moreover, it is preferable that the thickness of a positive electrode active material layer exists in the range of 0.1 micrometer-1000 micrometers, for example.

3. Next, the negative electrode active material layer in the present invention will be described. The negative electrode active material layer in the present invention is a layer containing at least a negative electrode active material, and may contain at least one of a solid electrolyte material, a conductive material and a binder as necessary. In particular, in the present invention, the negative electrode active material layer is preferably the above-described solid electrolyte material-containing body. This is because a negative electrode active material layer having high ion conductivity can be obtained. Examples of the negative electrode active material include a metal active material and a carbon active material. Examples of the metal active material include In, Al, Si, and Sn. On the other hand, examples of the carbon active material include mesocarbon microbeads (MCMB), highly oriented graphite (HOPG), hard carbon, and soft carbon. Moreover, when the negative electrode active material layer is the above-described solid electrolyte material-containing body, the potential of the negative electrode active material is preferably 0.3 V (vs Li) or higher, and is 0.5 V (vs Li) or higher. Is more preferable. This is because when the potential of the negative electrode active material is low, reduction of the sulfide solid electrolyte material may occur. Note that the conductive material and the binder used in the negative electrode active material layer are the same as those in the positive electrode active material layer described above. Moreover, it is preferable that the thickness of a negative electrode active material layer exists in the range of 0.1 micrometer-1000 micrometers, for example.

4). Other Configurations The battery of the present invention has at least the electrolyte layer, the positive electrode active material layer, and the negative electrode active material layer described above. Furthermore, it usually has a positive electrode current collector for collecting current of the positive electrode active material layer and a negative electrode current collector for collecting current of the negative electrode active material layer. Examples of the material for the positive electrode current collector include SUS, aluminum, nickel, iron, titanium, and carbon. Among them, SUS is preferable. On the other hand, examples of the material for the negative electrode current collector include SUS, copper, nickel, and carbon. Of these, SUS is preferable. In addition, the thickness and shape of the positive electrode current collector and the negative electrode current collector are preferably appropriately selected according to the use of the battery. Moreover, the battery case of a general battery can be used for the battery case used for this invention. Examples of the battery case include a SUS battery case.

5. Battery The battery of the present invention may be a primary battery or a secondary battery, but among them, a secondary battery is preferable. This is because it can be repeatedly charged and discharged and is useful, for example, as an in-vehicle battery. Examples of the shape of the battery of the present invention include a coin type, a laminate type, a cylindrical type, and a square type. Moreover, the manufacturing method of the battery of this invention will not be specifically limited if it is a method which can obtain the battery mentioned above, The method similar to the manufacturing method of a general battery can be used. For example, when the battery of the present invention is an all-solid battery, as an example of the manufacturing method thereof, a material constituting the positive electrode active material layer, a material constituting the solid electrolyte layer, and a material constituting the negative electrode active material layer are sequentially provided. Examples of the method include producing a power generation element by pressing, housing the power generation element inside the battery case, and caulking the battery case.

  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]
(Synthesis of sulfide solid electrolyte materials)
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.39019 g of Li ₂ S, 0.377515 g of P ₂ S ₅ and 0.232295 g of GeS ₂ to obtain a raw material composition. 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. As a result, an amorphized ion conductive material having a composition of Li _3.33 Ge _0.33 P _0.67 S ₄ was obtained. The above composition _is one that corresponds to the composition of x = 0.67 in _{Li (4-x) Ge (} 1-x) P x S 4.

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. Thereby, a crystalline sulfide solid electrolyte material having a composition of Li _3.33 Ge _0.33 P _0.67 S ₄ was obtained.

(Addition of binder)
235 mg of the obtained sulfide solid electrolyte material and 11.75 mg of styrene butadiene rubber (SBR, manufactured by JSR) were added to 1200 ml of dehydrated heptane and stirred with a stirrer for 24 hours to obtain a slurry. The obtained slurry was dried at 120 ° C. for 1 hour to obtain a mixture of the sulfide solid electrolyte material and SBR. The proportion of SBR in the mixture was 9.1% by volume.

[Comparative Example 1]
As a firing condition, a crystalline sulfide solid electrolyte was obtained in the same manner as in Example 1 except that the temperature was raised from room temperature to 700 ° C. over 6 hours, maintained at 700 ° C. for 8 hours, and then gradually cooled to room temperature. Obtained material. Moreover, the mixture was obtained like Example 1 except having used the obtained sulfide solid electrolyte material.

[Evaluation 1]
(X-ray diffraction measurement)
X-ray diffraction (XRD) measurement was performed using the sulfide solid electrolyte material synthesized in Example 1 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. 7, in 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, a diffraction intensity peak around 2 [Theta] = 29.58 ° and _{I A,} the intensity of the peak near 2 [Theta] = 27.33 ° and _{I B.} The value of _I B / _{I A} in Example 1 was 0.002, the value of _I B / _{I A} in Comparative Example 1 was 1.60.

(Resistivity measurement)
Resistivity measurement was performed using the sulfide solid electrolyte material synthesized in Example 1 and Comparative Example 1 and the mixture obtained in Example 1 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, the resistivity per unit length was calculated from the thickness and resistance of the sample (pellet). The results are shown in FIGS. 8 (a) and 8 (b). As shown in FIGS. 8A and 8B, in Comparative Example 1, the increase in resistivity due to the addition of SBR was as large as 2099.96 Ωcm, whereas in Example 1, 388.22 Ωcm and 1 / 5 or less was confirmed.

[Production Example 1]
(Synthesis of ion conductive materials)
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.7769 g of Li ₂ S, 0.8673 g of P ₂ S ₅ and 0.3558 g of GeS ₂ to obtain a raw material composition. Next, the raw material composition was molded into pellets, and the resulting 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 700 ° C. over 6 hours, maintained at 700 ° C. for 8 hours, and then gradually cooled to room temperature. Thus, a crystalline ion conductive material having a composition of Li _3.25 Ge _0.25 P _0.75 S ₄ was obtained. The above composition _is one that corresponds to the composition of x = 0.75 in _{Li (4-x) Ge (} 1-x) P x S 4.

(Synthesis of sulfide solid electrolyte materials)
Next, the obtained ion conductive material was pulverized using a vibration mill. TI-100 manufactured by CM Science Co., Ltd. was used for the vibration mill. Specifically, about 2 g of the ion conductive material obtained by the above method and an alumina vibrator (φ36.3 mm, height 48.9 mm) are placed in a 10 mL pot, and treated at a rotation speed of 1440 rpm for 30 minutes. Went. Thereafter, the ion conductive material having reduced crystallinity was formed into a pellet, and the obtained pellet was 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. Thereby, a crystalline sulfide solid electrolyte material having a composition of Li _3.25 Ge _0.25 P _0.75 S ₄ was obtained.

[Production Example 2]
The crystalline material is the same as in Production Example 1 except that the raw material composition used is a mixture of 0.7790 g of Li ₂ S, 0.7986 g of P ₂ S ₅ and 0.4224 g of GeS _2. An ion conductive material was obtained. The obtained ion conductive material has a composition of Li _3.3 Ge _0.3 P _0.7 S ₄ , and this composition is _{x in} Li _(4-x) Ge _(1-x) P _x S ₄ . = 0.7. Further, using this ion conductive material, a crystalline sulfide solid electrolyte material having a composition of Li _3.3 Ge _0.3 P _0.7 S ₄ was obtained in the same manner as in Production Example 1.

[Production Example 3]
The crystalline material is the same as in Production Example 1 except that the raw material composition used is a mixture of Li ₂ S 0.7811 g, P ₂ S ₅ 0.7329 g, and GeS ₂ 0.4860 g. An ion conductive material was obtained. The obtained ion conductive material has a composition of Li _3.35 Ge _0.35 P _0.65 S ₄ , which is the composition of _{x in} Li _(4-x) Ge _(1-x) P _x S ₄ . = 0.65 of the composition. Further, using this ion conductive material, a crystalline sulfide solid electrolyte material having a composition of Li _3.35 Ge _0.35 P _0.65 S ₄ was obtained in the same manner as in Production Example 1.

[Production Example 4]
A crystalline material was prepared in the same manner as in Production Example 1 except that the raw material composition used was a mixture of Li ₂ S 0.7831 g, P ₂ S ₅ 0.6685 g, and GeS ₂ 0.5484 g. An ion conductive material was obtained. The obtained ion conductive material has a composition of Li _3.4 Ge _0.4 P _0.6 S ₄ , and this composition is _{x in} Li _(4-x) Ge _(1-x) P _x S ₄ . Corresponds to the composition of 0.6. Further, using this ion conductive material, a crystalline sulfide solid electrolyte material having a composition of Li _3.4 Ge _0.4 P _0.6 S ₄ was obtained in the same manner as in Production Example 1.

[Comparative Production Examples 1 to 4]
The crystalline ion conductive materials obtained in Production Examples 1 to 4 were respectively used as comparative samples.

[Evaluation 2]
(X-ray diffraction measurement)
X-ray diffraction (XRD) measurement was performed using the sulfide solid electrolyte material obtained in Production Example 3. The result is shown in FIG. FIG. 9A is an XRD pattern measured with CuKα rays, and FIG. 9B is an XRD pattern measured with synchrotron radiation (wavelength 1.2 mm). As shown in FIGS. 9A and 9B, in Production Example 3, a single-phase sulfide solid electrolyte material was obtained. When measured by CuKα rays, the peak positions are 2θ = 17.38 °, 20.18 °, 20.44 °, 23.56 °, 23.96 °, 24.93 °, 26.96 °, 29 0.07 °, 29.58 °, 31.71 °, 32.66 ° and 33.39 °. On the other hand, when measured with synchrotron radiation (wavelength: 1.2 mm), the peak positions are 2θ = 9.63 °, 10.94 °, 11.21 °, 13.52 °, 15.69 °, 15.88. °, 18.29 °, 18.61 °, 19.35 °, 20.92 °, 22.94 °, 24.48 °, 24.56 °. 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 °).

  Next, X-ray diffraction measurement (using CuKα rays) was performed using the sulfide solid electrolyte material obtained in Production Examples 1 to 4 and the comparative sample obtained in Comparative Production Examples 1 to 4. The results are shown in FIGS. As shown in FIG. 10, the sulfide solid electrolyte material obtained in Production Example 1 had a peak at a position of 2θ = 29.36 °. This peak is a peak of the crystal phase A having high Li ion conductivity. The peaks attributed to the crystal phase A are 2θ = 17.28 °, 20.04 °, 20.30 °, 23.82 °, 26.78 °, 29.36 ° in order from the left of the drawing. Each peak is considered.

Further, as shown in FIG. 10, 2θ = 29.58 ° around (in the case of Production Example 1, 2θ = 29.36 °) to the diffraction intensity of the peak of the _{I A,} the peak around 2 [Theta] = 27.33 ° the intensity and _{I B,} the diffraction intensity of the peak near 2 [Theta] = 29.78 ° and _{I C.} The value of _I B / _{I A} in Preparation Example 1 is _0.25, the value of I C / _{I A} was 0.07. On the other hand, the value of _I B / _{I A} in Comparative Preparation Example 1 is _1.4, the value of I C / _{I A} was 1.54. Also, as shown in FIGS. 11 to 13, the sulfide solid electrolyte material obtained in Production Examples 2 to 4 similarly had a peak in the vicinity of 2θ = 29.58 °. As for the value of _I B / _{I A} and _I C / _{I A} in the preparation Examples 2-4 are set forth in Table 1 below. As shown in FIG. 13, in Production Example 4, a single-phase sulfide solid electrolyte material was obtained as in Production Example 3.

(X-ray structural analysis)
The crystal structure of the sulfide solid electrolyte material obtained in Production Example 3 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.

(Measurement of Li ion conductivity)
Li ion conductivity at 25 ° C. was measured using the sulfide solid electrolyte material obtained in Production Examples 1 to 4 and the comparative sample obtained in Comparative Production Examples 1 to 4. First, an appropriate amount of sample is weighed in a glove box in an argon atmosphere, put in a polyethylene terephthalate tube (PET tube, inner diameter 10 mm, outer diameter 30 mm, height 20 mm), and powder molded from carbon tool steel S45C anvil from above and below. I pinched it with a jig. Next, using a uniaxial press machine (P-6 manufactured by Riken Seiki Co., Ltd.), pressing was performed at a display pressure of 6 MPa (molding pressure: about 110 MPa) to mold pellets having a diameter of 10 mm and an arbitrary thickness. Next, 13 mg to 15 mg of gold powder (made by Niraco, dendritic, particle size of about 10 μm) is placed on both sides of the pellet, uniformly dispersed on the pellet surface, and at a display pressure of 30 MPa (molding pressure of about 560 MPa). Molded. Thereafter, the obtained pellets were placed in a closed electrochemical cell capable of maintaining an argon atmosphere.

  For measurement, a frequency response analyzer FRA (Frequency Response Analyzer) is used, Solartron's impedance gain phase analyzer (solartron 1260), and a thermostat is a small environmental tester (Espec corp, SU-241, -40 ℃) ~ 150 ° C) was used. Measurement was started from the high frequency region under the conditions of an AC voltage of 10 mV to 1000 mV, a frequency range of 1 Hz to 10 MHz, an integration time of 0.2 seconds, and a temperature of 23 ° C. Zplot was used as measurement software, and Zview was used as analysis software. The obtained results are shown in Table 1.

As shown in Table 1, Production Examples 1 to 4 each had higher Li ion conductivity than Comparative Production Examples 1 to 4. Therefore, the proportion of the crystal phase having a peak around 2 [Theta] = 29.58 ° is increased, the value of I B _/ I _A is small, Li ion conductivity was confirmed to be improved. Note that, as shown in Table 1, the ion-conducting material produced by a solid phase method which is a conventional method, can not be the value of I B _/ I _A below 0.50, I C _/ I The value of _A could not be made 0.20 or less. FIG. 14 is a graph showing the relationship between the intensity ratio (I _B / I _A ) and Li ion conductivity in Production Examples 1 to 4 and Comparative Production Examples 1 to 4. As shown in FIG. _14, the value of I B / _{I A} is in the case of less than 0.50, it was confirmed that the Li ion conductivity is high. As shown in FIG. 15, Production Examples 1 to 3 each had higher Li ion conductivity than Comparative Production Examples 1 to 3.

[Reference Examples 1-3]
The crystalline ion conductive materials obtained in Production Examples 1 to 3 were used as reference samples, respectively.

[Reference Example 4]
The crystalline material is the same as in Production Example 1 except that the raw material composition used is a mixture of Li ₂ S 0.7747 g, P ₂ S ₅ 0.9370 g, and GeS ₂ 0.2883 g. An ion conductive material was obtained. The resulting ion conductive material has a composition of Li _3.2 Ge _0.2 P _0.8 S ₄ , which is the _{x in} Li _(4-x) Ge _(1-x) P _x S ₄ . = 0.8 corresponds to the composition. This ion conductive material was used as a reference sample.

[Evaluation 3]
Using the reference samples obtained in Reference Examples 1 to 4, X-ray diffraction measurement and measurement of Li ion conductivity were performed. The results are shown in FIGS. 16 and 17, respectively. As shown in FIG. 16, when the value of x increases, the diffraction intensity of the peak near 2θ = 29.58 ° decreases, and the diffraction intensity of the peaks near 2θ = 27.33 ° and 29.78 ° increases. You can see it grows. This indicates that as the value of x increases, the proportion of the crystal phase B having low Li ion conductivity becomes relatively high. In particular, in Reference Example 4, the crystal phase A having a peak near 2θ = 29.58 ° completely disappears, and only the peak of the crystal phase B is confirmed. Therefore, looking at FIG. 17, the Li ion conductivity of Reference Example 4 is much lower than the Li ion conductivity of Reference Examples 1 to 3. Therefore, it is suggested that the crystal phase A included in the reference samples of Reference Examples 1 to 3 has significantly higher Li ion conductivity than the crystal phase B. From this, it was confirmed that the sulfide solid electrolyte material of the present invention containing a large amount of the crystal phase A has high Li ion conductivity.

[Production Example 5]
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.3934 g of Li ₂ S, 0.2719 g of P ₂ S ₅ and 0.3346 g of GeS ₂ to obtain a raw material composition. 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 for 60 hours at a base plate rotation speed of 370 rpm. As a result, an amorphous ion conductive material having a composition of Li _3.5 Ge _0.5 P _0.5 S ₄ was obtained. The above composition _is one that corresponds to the composition of x = 0.5 in _{Li (4-x) Ge (} 1-x) P x S 4.

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. Thus, a crystalline sulfide solid electrolyte material having a composition of Li _3.5 Ge _0.5 P _0.5 S ₄ was obtained.

[Comparative Production Example 5-1]
The amorphous ion conductive material obtained in Production Example 5 was used as a comparative sample.

[Comparative Production Example 5-2]
As a firing condition, a comparative sample was obtained in the same manner as in Production Example 5 except that the temperature was raised from room temperature to 300 ° C. over 6 hours, maintained at 300 ° C. for 8 hours, and then gradually cooled to room temperature.

[Comparative Production Example 5-3]
As a firing condition, a comparative sample was obtained in the same manner as in Production Example 5 except that the temperature was raised from room temperature to 700 ° C. over 6 hours, maintained at 700 ° C. for 8 hours, and then gradually cooled to room temperature.

[Production Example 6]
Amorphous in the same manner as in Production Example 5 except that the raw material composition used was a mixture of 0.3905 g of Li ₂ S, 0.3666 g of P ₂ S ₅ and 0.2429 g of GeS _2. A quality ion conductive material was obtained. The obtained ion conductive material has a composition of Li _3.35 Ge _0.35 P _0.65 S ₄ , which is the composition of _{x in} Li _(4-x) Ge _(1-x) P _x S ₄ . = 0.65 of the composition. Further, by using the ion-conductive material, in the same manner as in Preparation Example _5, to give a sulfide solid electrolyte material of the crystalline having a composition of _{Li 3.35 Ge 0.35 P 0.65 S 4} .

[Comparative Production Example 6]
The amorphous ion conductive material obtained in Production Example 6 was used as a comparative sample.

[Production Example 7]
Amorphous in the same manner as in Production Example 5, except that the raw material composition was 0.3895 g of Li ₂ S, 0.3997 g of P ₂ S ₅ and 0.2108 g of GeS ₂ was used. A quality ion conductive material was obtained. The obtained ion conductive material has a composition of Li _3.3 Ge _0.3 P _0.7 S ₄ , and this composition is _{x in} Li _(4-x) Ge _(1-x) P _x S ₄ . = 0.7. Further, using this ion conductive material, a crystalline sulfide solid electrolyte material having a composition of Li _3.3 Ge _0.3 P _0.7 S ₄ was obtained in the same manner as in Production Example 5.

[Comparative Production Example 7]
The amorphous ion conductive material obtained in Production Example 7 was used as a comparative sample.

[Evaluation 4]
(X-ray diffraction measurement)
X-ray diffraction measurement using the sulfide solid electrolyte material obtained in Production Examples 5 to 7 and the comparative samples obtained in Comparative Production Examples 5-1, 5-2, 5-3, 6, and 7. (Use CuKα radiation). The results are shown in FIGS. First, as shown in FIGS. 18 to 20, the comparative samples obtained in Comparative Production Examples 5-1, 6 and 7 are almost completely amorphous although a slight Li ₂ S peak is detected. It was confirmed that it was qualitative. On the other hand, all the sulfide solid electrolyte materials obtained in Production Examples 5 to 7 had the same peak as in Production Example 3 described above, and were confirmed to be single-phase sulfide solid electrolyte materials.

  Next, as shown in FIG. 21, in Comparative Production Example 5-2 (heating at 300 ° C.), the crystalline phase A having high Li ion conductivity does not precipitate, and Comparative Production Example 5-3 (at 700 ° C.). In the heating step, a phase other than the crystal phase A having high Li ion conductivity was precipitated. For this reason, the heating temperature is preferably higher than 300 ° C. and lower than 700 ° C.

(Measurement of Li ion conductivity)
Li ion conductivity was measured using the sulfide solid electrolyte material obtained in Production Examples 5 to 7 and the comparative samples obtained in Comparative Production Examples 5-1, 6 and 7. The measurement method is the same as described above. The results are shown in Table 2. As shown in Table 2, Production Examples 5 to 7 each had high Li ion conductivity.

(Raman spectroscopy measurement)
The Raman spectroscopic measurement was performed on the comparative samples obtained in Comparative Production Examples 5-1 and 6. For Raman spectroscopic measurement, Nanofinder SOLAR T II manufactured by Tokyo Instruments was used. The result is shown in FIG. As shown in FIG. 22, in the comparative samples obtained in Production Examples 5-1 and ₆ , the peak of P ₂ S ₅ was not detected, and the vibration of PS ₄ ³⁻ was detected in the vicinity of 420 cm ^−1. It was. From this, it was confirmed by the ball mill that all the raw material P ₂ S ₅ reacted with Li ₂ S and was converted to chemically stable PS ₄ ³⁻ . Further, since P ₂ S ₅ was converted to PS ₄ ³⁻ , in Production Examples 5 and 6, no trace of P ₂ S ₅ melting after firing was observed.

[Production Example 8]
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), diphosphorus trisulfide (P ₂ S ₃ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.88053 g of Li ₂ S, 0.567995 g of P ₂ S ₅ , 0.20204 g of P ₂ S ₃ and 0.3494 g of GeS _2. A raw material composition was obtained. Next, 2 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. Thus, an amorphous ion conductive material having a composition of Li _3.75 Ge _0.25 P (III) _0.25 P (V) _0.5 S ₄ was obtained.

Next, the obtained ion conductive material is put in an aluminum container, and heated from room temperature to 550 ° C. at 10 ° C./min under Ar gas flow (80 mL / min), and then 550 at 10 ° C./min. The temperature was lowered from ℃ to room temperature. Thus, a crystalline sulfide solid electrolyte material having a composition of Li _3.75 Ge _0.25 P (III) _0.25 P (V) _0.5 S ₄ was obtained.

[Production Example 9]
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), aluminum sulfide (Al ₂ S ₃ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.88504 g of Li ₂ S, 0.570864 g of P ₂ S ₅ , 0.192826 g of Al ₂ S ₃ and 0.351267 g of GeS _2. A raw material composition was obtained. A crystalline sulfide solid electrolyte material was obtained in the same manner as in Production Example 8 except that this raw material composition was used. The composition of the obtained sulfide solid electrolyte material is Li _3.75 Ge _0.25 Al _0.25 P _0.5 S ₄ .

[Production Example 10]
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), zirconium sulfide (ZrS ₂ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.769424 g of Li ₂ S, 0.5751 g of P ₂ S ₅ , 0.327191 g of ZrS ₂ and 0.371649 g of GeS ₂ A composition was obtained. A crystalline sulfide solid electrolyte material was obtained in the same manner as in Production Example 8 except that this raw material composition was used. The composition of the obtained sulfide solid electrolyte material is Li _3.5 Ge _0.25 Zr _0.25 P _0.5 S ₄ .

[Production Example 11]
As starting materials, lithium sulfide (Li ₂ S), zinc sulfide (ZnS), diphosphorus pentasulfide (P ₂ S ₅ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.687245 g of Li ₂ S, 0.146712 g of ZnS, 0.522737 g of P ₂ S ₅ and 0.643307 g of GeS ₂ I got a thing. A crystalline sulfide solid electrolyte material was obtained in the same manner as in Production Example 8 except that this raw material composition was used. The composition of the obtained sulfide solid electrolyte material is Li _3.18 Zn _0.16 Ge _0.5 P _0.5 S ₄ .

[Production Example 12]
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), niobium sulfide (NbS ₂ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.76787 g of Li ₂ S, 0.53066 g of P ₂ S ₅ , 0.374919g of NbS _2, and 0.326533 g of GeS _2. A composition was obtained. A crystalline sulfide solid electrolyte material was obtained in the same manner as in Production Example 8 except that this raw material composition was used. The composition of the obtained sulfide solid electrolyte material is Li _3.5 Ge _0.25 Nb _0.25 P _0.5 S ₄ .

[Production Example 13]
As starting materials, lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ), silicon sulfide (SiS ₂ ), and germanium sulfide (GeS ₂ ) were used. These powders were mixed in a glove box under an argon atmosphere at a ratio of 0.81323 g of Li ₂ S, 0.76333 g of P ₂ S ₅ , 0.170524 g of SiS ₂ and 0.252913 g of GeS ₂ A composition was obtained. A crystalline sulfide solid electrolyte material was obtained in the same manner as in Production Example 8 except that this raw material composition was used and the maximum temperature of the heat treatment was changed from 550 ° C. to 650 ° C. The composition of the obtained sulfide solid electrolyte material is Li _3.55 Ge _0.175 Si _0.175 P _0.65 S ₄ .

[Evaluation 5]
(X-ray diffraction measurement)
X-ray diffraction measurement (using CuKα rays) was performed using the sulfide solid electrolyte materials obtained in Production Examples 8 to 13. The results are shown in FIGS. Further, 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,} was determined a value of _I B / I _A. The results are shown in Table 3.

As shown in FIGS. 23 and 24, the sulfide solid electrolyte materials obtained in Production Examples 8 to 13 all had a large peak in the vicinity of 2θ = 29.58 °. Further, as shown in Table 3, in Production Example 8, the intensity of the peak near θ = 27.33 ° was not detected, and I _B / I _A = 0. From this result, it was confirmed that even when a part of LiGePS-based Ge was substituted with trivalent P, a crystal phase (crystalline phase A) having high ion conductivity was deposited. In Production Example 9, the intensity of the peak around θ = 27.33 ° was not detected, and I _B / I _A = 0. From this result, it was confirmed that even when a part of LiGePS-based Ge was substituted with Al, a crystal phase (crystal phase A) having high ion conductivity was deposited. In Production Example 10, the intensity of the peak around θ = 27.33 ° was not detected, and I _B / I _A = 0. From this result, it was confirmed that even when a part of LiGePS-based Ge was substituted with Zr, a crystal phase (crystal phase A) having high ion conductivity was deposited. In Production Example 11, the intensity of the peak around θ = 27.33 ° was detected, and I _B / I _A = 0.15. From this result, it was confirmed that even if a part of LiGePS-based Li was replaced with Zn, a large amount of high ion conductive crystal phase (crystal phase A) was precipitated. In Production Example 12, the intensity of the peak around θ = 27.33 ° was detected, and I _B / I _A = 0.14. From this result, it was confirmed that even if a part of LiGePS-based Ge was substituted with Nb, a large amount of high ion conductive crystal phase (crystal phase A) was precipitated. In Production Example 13, the intensity of the peak around θ = 27.33 ° was not detected, and I _B / I _A = 0. From this result, it was confirmed that even when a part of LiGePS-based Ge was replaced with Si, a crystal phase (crystal phase A) having high ion conductivity was deposited.

[Calculation Example 1]
With respect to the composition Li _3.5 Ge _0.5 P _0.5 S ₄ (Li ₂₁ Ge ₃ P ₃ S ₂₄ ) described in Production Example 5, when Ge is substituted with Si, the predetermined crystal structure in the present invention exists. It was estimated by the first principle calculation. Using the heat of formation of Li metal, Ge metal, Si metal, P crystal, and S crystal as zero reference, the enthalpy of formation when Ge in the crystal was replaced with Si was calculated.

  Here, the first-principles calculation is a high-precision calculation method that does not include empirical parameters based on the density functional theory. Using this calculation method, the heat of formation (generation enthalpy) of the crystal was calculated. The heat of formation is reaction heat accompanied by a reaction of synthesizing 1 mol of a compound from a simple substance constituting the substance, with the heat of formation of a stable simple substance as zero reference. Generally, it is described as a generation enthalpy change ΔHf as a heat of generation under a constant pressure. When the enthalpy balance of the process of changing from reactant to product takes a negative value, heat is released out of the reaction system and an exothermic reaction occurs. That is, the product can be present.

(Calculation formula of generation enthalpy)
For example, in the case of Li ₂₁ Ge ₃ P ₃ S ₂₄ , the generation enthalpy can be expressed by the following equation.
Generation enthalpy = 21E _tot (Li metal) + 3E _tot (Ge metal) + 3E _tot (P crystal) + 24E _tot (S crystal) −E _tot (Li ₂₁ Ge ₃ P ₃ S ₂₄ crystal)
Note that E _tot is the energy of one atom in the total energy of the electronic state of the crystal obtained from the first principle calculation.

(First-principles calculation)
The first principle calculation is performed according to the following procedure. First, a calculation model is constructed based on the experimental values of the related crystal lattice constant, space group, and atomic coordinates. Next, the lattice constant and the atom position are optimized by a structure optimization calculation tool using general first-principles calculation software (CASTEP, VASP, etc.) so that the internal energy is minimized. At the same time, the total energy of the electronic state of the crystal is calculated. Based on the total energy of the electronic state of each crystal obtained, the generation enthalpy is calculated by the above formula. As a first-principles calculation method, a plane wave basis is used for describing an electron wave function, a generalized gradient approximation (GGA-PBE) is used for exchange interaction, and a PAW method is used for handling inner-shell electrons. The calculation conditions are optimized for each crystal.

[Calculation Examples 2 to 6]
For the composition Li _3.5 Ge _0.5 P _0.5 S ₄ (Li ₂₁ Ge ₃ P ₃ S ₂₄ ) described in Production Example 5, when Ge is replaced with Sn, Pb, Zr, Al, and B, respectively Whether or not the predetermined crystal structure in the present invention can exist was estimated by the first principle calculation. Calculation examples 5 and 6 are results when Li is added.

[Evaluation 6]
The results of the first principle calculation are shown in Table 4.

  As shown in Table 4, the production enthalpies were all negative. This suggests that a desired crystal can be synthesized when Ge is substituted with each of the above elements.

DESCRIPTION OF SYMBOLS 1 ... Sulfide solid electrolyte material 2 ... Binder 10 ... Solid electrolyte material containing body 11 ... Positive electrode active material layer 12 ... Negative electrode active material layer 13 ... Electrolyte layer 14 ... Positive electrode collector 15 ... Negative electrode collector 16 ... Battery Case 20 ... Battery

Claims (6)

It has a composition of Li _(4-x) Ge _(1-x) P _x S ₄ (x satisfies 0 <x <1), and 2θ = 20.18 ° in X-ray diffraction measurement using CuKα rays. It has a peak at the positions of ± 0.50 °, 20.44 ° ± 0.50 °, 26.96 ° ± 0.50 °, 29.58 ° ± 0.50 °, and 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 0.50 A sulfide solid electrolyte material that is less than, and
A solid electrolyte material-containing body comprising: a binder which is a polymer having a double bond in the main chain. 2. The solid electrolyte material-containing body according to claim 1, wherein the value of I _B / I _A is 0.25 or less.   In the X-ray diffraction measurement using CuKα ray, the sulfide solid electrolyte material has 2θ = 17.38 °, 23.56 °, 23.96 °, 24.93 °, 29.07 °, 31.71 °. , 32.66 °, 33.39 ° (note that these positions may be back and forth within a range of ± 0.50 °). 3. The solid electrolyte material-containing body according to 2. 4. The solid electrolyte material-containing body according to claim 1 , wherein x satisfies 0.5 ≦ x ≦ 0.8. 5. The solid electrolyte material-containing body according to any one of claims 1 to 4 , wherein the binder is styrene butadiene rubber (SBR). A battery comprising a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and an electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer. And
6. The battery according to claim 1, wherein at least one of the positive electrode active material layer, the negative electrode active material layer, and the electrolyte layer is the solid electrolyte material-containing body according to any one of claims 1 to 5. .