JP6309344B2 - Solid electrolyte and battery - Google Patents

Description

  The present invention relates to a solid electrolyte used for an all-solid secondary battery or the like.

  The lithium ion conductive solid electrolyte is useful as an electrolyte of an all-solid secondary battery. A sulfide solid electrolyte using lithium sulfide and diphosphorus pentasulfide as raw materials has high ionic conductivity, but further improvement is expected.

The comparative examples of Non-Patent Document 1 and Patent Document 1 describe a solid electrolyte that is 80:20 in terms of lithium sulfide and phosphorus pentasulfide.
On the other hand, by adding 1.2 to 20% by mass of lithium hydroxide to 100% by mass of lithium sulfide in Patent Document 2, the progress of vitrification becomes faster or the glass is baked at a glass transition temperature or higher. Although it is described that ceramics can be obtained, those having high ionic conductivity have not been obtained.

JP 2005-228570 A JP 2004-348773 A

Solid State Ionics 154-155 (2002)

  An object of the present invention is to provide a novel solid electrolyte.

According to the present invention, the following solid electrolyte and the like are provided.
1. A solid electrolyte containing Li, P, S, O and H, wherein the molar ratio of each element satisfies the following formulas (1) to (5).
Li: P: S: O: H = (160 + 2k + L) :( 40-2k) :( 180-4k): M: N (1)
−1.5 ≦ k ≦ 1.5 (2)
0 ≦ L ≦ M + N (3)
0 <M ≦ 100 (4)
0 <N ≦ 100 (5)
2. Li, P, S, O, and _H, Li _{2 S,} when converted with _{P 2 S 5, LiOH, Li} 2 S, the molar ratio of P 2 S 5, LiOH, formula (6), (2), The solid electrolyte according to 1, which satisfies (4).
Li ₂ S: P ₂ S ₅ : LiOH = (80 + k) :( 20−k): M (6)
−1.5 ≦ k ≦ 1.5 (2)
0 <M ≦ 100 (4)
3. Furthermore, the solid electrolyte of 1 or 2 containing a halogen element.
4). 3. The solid electrolyte according to 1 or 2, comprising only Li, P, S, O, and H elements.
5. 5. The solid electrolyte according to any one of 1 to 4, which is an amorphous solid electrolyte.
6). 5. The solid electrolyte according to any one of 1 to 4, which is a crystalline solid electrolyte.
7). 7. The solid electrolyte according to 6, wherein the crystal is a thiolithicone type II crystal.
8). 8. The solid electrolyte according to 6 or 7, wherein the crystal ratio is 30% to 99%.
9. Solid electrolyte in any one of 1-8 whose Formula (2) is -1.0 <= k <= 1.0.
10. 10. The solid electrolyte according to 9, wherein the formula (2) is −0.8 ≦ k ≦ 0.8.
11. The solid electrolyte according to any one of 1 to 10, wherein Formula (3) satisfies 0 ≦ L ≦ M and / or 0 ≦ L ≦ N.
12 The solid electrolyte according to any one of 1 to 11, wherein Formula (4) is 0 <M ≦ 60.
13. 13. The solid electrolyte according to 12, wherein the formula (4) is 1.5 <M ≦ 60.
14 14. The solid electrolyte according to 13, wherein the formula (4) is 2 ≦ M ≦ 50.
15. The solid electrolyte according to any one of 1 to 14, wherein the formula (5) is 0 <N ≦ 60.
16. 16. The solid electrolyte according to 15, wherein the formula (5) is 1.5 <N ≦ 60.
17. The solid electrolyte according to 16, wherein the formula (5) is 2 ≦ N ≦ 50.
18. The solid electrolyte according to any one of 1 to 17, wherein M = N.
19. Solid electrolyte in any one of 1-18 whose ion conductivity is 1.0 * 10 < ^-4 > -5.0 * 10 < ^-3 > S / cm.
20. The solid electrolyte according to any one of 1 to 19, wherein the volume reference average particle diameter is 0.01 μm or more and 100 μm or less.
21. Solid electrolyte in any one of 1-20 whose crystallization temperature is 100 to 300 degreeC.
22. The solid electrolyte according to any one of 1 to 21, which does not contain lithium sulfide.
23. A method for producing a solid electrolyte, comprising reacting Li ₂ S and a phosphorus compound to produce the solid electrolyte according to 1.
24. 24. The method for producing a solid electrolyte according to 23, wherein Li ₂ S, phosphorus compound and LiOH are reacted.
25. 25. The method for producing a solid electrolyte according to 23 or 24, wherein the phosphorus compound is P ₂ S ₅ .
The solid electrolyte layer containing the solid electrolyte in any one of 26.1-22.
27. A positive electrode mixture comprising a positive electrode active material and the solid electrolyte according to any one of 1 to 22.
A positive electrode comprising the positive electrode mixture according to 28.27.
29. A negative electrode mixture comprising a negative electrode active material and the solid electrolyte according to any one of 1 to 22.
A negative electrode comprising the negative electrode mixture according to 30.29.
A battery comprising at least one of the solid electrolyte layer according to 31.26, the positive electrode according to 28, and the negative electrode according to 30.

  According to the present invention, a novel solid electrolyte can be provided.

The solid electrolyte of the present invention contains the elements Li, P, S, O, and H, and the molar ratio of each element satisfies the following formulas (1) to (5).
Li: P: S: O: H = (160 + 2k + L) :( 40-2k) :( 180-4k): M: N (1)
−1.5 ≦ k ≦ 1.5 (2)
0 ≦ L ≦ M + N (3)
0 <M ≦ 100 (4)
0 <N ≦ 100 (5)

In Formula (2), it is preferably −1.0 ≦ k ≦ 1.0, and more preferably −0.8 ≦ k ≦ 0.8.
In the formula (3), preferably, one or more of 0 ≦ L ≦ M and 0 ≦ L ≦ N are satisfied.
In the formula (4), preferably 0 <M ≦ 60, for example, 0.5 <M ≦ 60. More preferably, 1.5 <M ≦ 60, still more preferably 2 ≦ M ≦ 60, for example, 3 ≦ M ≦ 50, 4 ≦ M ≦ 40, and 5 ≦ M ≦ 30.
In the formula (5), preferably 0 <N ≦ 60, for example, 0.5 <N ≦ 60. More preferably, 1.5 <N ≦ 60, still more preferably 2 ≦ N ≦ 60, for example, 3 ≦ N ≦ 50, 4 ≦ N ≦ 40, and 5 ≦ N ≦ 30.
Preferably M = N.

All elements Li contained in the solid electrolyte, P, S, O and _H, Li _{2 S,} when converted with _{P 2 S 5, LiOH, Li} 2 S, the molar ratio of P 2 S 5, LiOH, formula It is preferable to satisfy (6).
Li ₂ S: P ₂ S ₅ : LiOH = (80 + k) :( 20−k): M (6)

The second solid electrolyte of the present invention contains the elements Li, P, S, O and H, and the molar ratio of each element satisfies the following formulas (7), (8) and (9):
Li: P: S: O: H = (155 + 2p + Q) :( 45-2p) :( 190-4p): Q: Q (7)
-4.0 ≦ p ≦ 4.0 (8)
(3-0.1p) <Q ≦ 100 (9)

The above formula (9) is preferably (4-0.1p) <Q ≦ 100, more preferably (5-0.1p) <Q ≦ 100, and more preferably (6-0.1p). <Q ≦ 100.
Further, the above formula (9) can be expressed by, for example, (4-0.1p) <Q ≦ 50, (4-0.1p) <Q ≦ 30, (4-0.1p) <Q ≦ 20, (5-0 .1p) <Q ≦ 30, (5-0.1p) <Q ≦ 20, (6-0.1p) <Q ≦ 30, (6-0.1p) <Q ≦ 20, (7-0.1p ) <Q ≦ 30, or (7−0.1p) <Q ≦ 20.

All elements Li contained in the second solid electrolyte, P, S, O and _H, Li _{2 S,} when converted with _{P 2 S 5, LiOH, Li} 2 S, the molar ratio of P 2 S 5, LiOH It is preferable that the following formula (10) is satisfied.
_{Li 2 S: P 2 S 5} : LiOH = (77.5 + p) :( 22.5-p): Q (10)
Hereinafter, the term “solid electrolyte of the present invention” or simply “solid electrolyte” includes both the first solid electrolyte and the second solid electrolyte of the present invention described above.

  The solid electrolyte of the present invention may further contain a halogen element such as I, Br, or Cl. Specifically, there are a sulfide-based solid electrolyte containing Li, P, S and I, a sulfide-based solid electrolyte containing Li, P, S and Br, and a sulfide-based solid electrolyte containing Li, P, S and Cl. Can be mentioned.

When converted by Li ₂ S, P ₂ S ₅ , LiOH, the ratio of the molar amount of halide to the total molar amount of Li ₂ S and P ₂ S ₅ is preferably [Li ₂ S + P ₂ S ₅ ]: halogen Compound = 50: 50 to 99: 1, more preferably [Li ₂ S + P ₂ S ₅ ]: halide = 60: 40 to 98: 2, more preferably [Li ₂ S + P ₂ S ₅ ]: halogen Compound = 70: 30 to 98: 2, particularly preferably [Li ₂ S + P ₂ S ₅ ]: halide = 72: 28 to 98: 2, for example, [Li ₂ S + P ₂ S ₅ ]: halide = _{72: 28~90: 10, [Li} 2 S + P 2 S 5]: halides = 75: 25 to 88: a 12.

  The solid electrolyte can contain elements such as B, Al, Si, and Ge.

  The solid electrolyte may be composed of only Li, P, S, O, and H elements. Further, the solid electrolyte may not contain lithium sulfide by sufficiently proceeding with the reaction described later. By not containing lithium sulfide, water resistance is improved.

The solid electrolyte may be amorphous or crystalline. The sulfide solid electrolyte glass (non-crystal) can be crystallized at a temperature equal to or higher than the glass transition temperature to form a glass ceramic (crystal).
The crystal structure contained in this glass ceramic includes a Li ₃ PS ₄ crystal structure, a Li ₄ P ₂ S ₆ crystal structure, a Li ₇ PS ₆ crystal structure, a Li ₇ P ₃ S ₁₁ crystal structure, and a Li _4-x Ge _{1− x} P _x S ₄ series thiolysicon type II and type III crystal structures (see Kanno et al., Journal of The Electrochemical Society, 148 (7) A742-746 (2001)). However, the crystal structure contained in this glass ceramic is not limited to these.


The crystallinity is usually 20% or more and 99% or less, for example, 25% or more and 90% or less, 30% or more and 80% or less.

Sulfide solid electrolyte glass ceramics of the present invention, even in a powder state, preferably has a _{Li 4-x Ge 1-x} P x S 4 based Chiorishikon II type crystal structure exhibiting high ion conductivity at room temperature. By having this crystal structure, high ion conductivity, for example, ion conductivity of 0.5 mS / cm or more can be achieved.

The solid electrolyte of the present invention can have a desired ionic conductivity by having a molar ratio with the above elements. According to the above preferred example, it is possible to have an ionic conductivity of 1.0 × 10 ^{−4 to} 5.0 × 10 ⁻³ S / cm. For example, they are 5.0 * 10 < ^-4 > -5.0 * 10 < ^-3 > S / cm, 8.0 * 10 < ^-4 > -5.0 * 10 < ^-3 > S / cm.

When the solid electrolyte is in the form of particles, the volume-based average particle diameter is preferably 0.01 μm or more and 100 μm or less. More preferably, 0.01-50 micrometers, especially 0.1-20 micrometers are good. If it is less than 0.01 μm, it tends to agglomerate and difficult to handle, and if it exceeds 100 μm, a defective phenomenon occurs in coating or the like.
The measurement method of the volume reference average particle diameter (Mean Volume Diameter, hereinafter referred to as “particle diameter”) is preferably performed by a laser diffraction particle size distribution measurement method.
Laser diffraction particle size distribution measurement method can measure the particle size distribution without drying the solid electrolyte, and measure the particle size distribution by irradiating the solid electrolyte particles with laser and analyzing the scattered light Can do.
As an example of measurement when the laser diffraction particle size distribution analyzer is a master sizer 2000 manufactured by Malvern Instruments Ltd., 110 ml of dehydrated toluene was added to the dispersion tank of the apparatus, and 6% of the dehydrated dispersant was added. It is better to measure under conditions.

[Method for producing solid electrolyte]
For the solid electrolyte, an MM (mechanical milling) method, a melting method, a method of contacting a raw material in a hydrocarbon solvent (WO2009 / 047977), a means of contacting the raw material in a hydrocarbon solvent, and a pulverizing synthesis means alternately It can be produced by a method of performing (Japanese Unexamined Patent Application Publication No. 2010-140893), a method of performing a pulverizing synthesis step after contacting a raw material in a solvent (PCT / JP2012 / 005992), and other methods.

The solid electrolyte of the present invention may be any raw material as long as it satisfies the above element ratio.
As a raw material, it is preferable to use at least Li ₂ S, it is more preferable to use a phosphorus sulfide Li ₂ S, it is more preferable to use a Li ₂ S and _P 2 _{S 5.}
It is also preferable to use Li ₂ S, a phosphorus compound, and a hydroxide as raw materials. Examples of the hydroxide include LiOH. Hydroxides such as LiOH are inexpensive.

A halogen compound such as lithium halide may be added to the raw material. For example, there are lithium iodide, lithium bromide, lithium chloride, lithium fluoride, and the like.

In addition to the above raw materials, the raw materials include SiS ₂ (silicon sulfide), Li ₄ SiO ₄ (lithium orthosilicate), Al ₂ S ₃ (aluminum sulfide), simple phosphorus (P), simple sulfur (S), silicon ( Si), GeS ₂ (germanium sulfide), B ₂ S ₃ (diarsenic trisulfide), Li ₃ PO ₄ (lithium phosphate), Li ₄ GeO ₄ (lithium germanate), LiBO ₂ (lithium metaborate), LiAlO ₃ (Lithium aluminate), LiSH and the like can be selected and used.

Specifically, as examples of combinations of raw _{materials, LiOH-Li 2 S-P} 2 S 5, LiOH-LiI-Li 2 S-P 2 S 5, LiOH-LiBr-Li 2 S-P 2 S 5, LiOH _{-LiCl-Li 2 S-P 2} S 5 and the like.

By satisfying the following formulas (1) to (5), for example, by changing Li ₂ S: P ₂ S ₅ used as a raw material to 79 to 81:19 to 21, the P ₂ S ₇ structure having bridging sulfur is substantially obtained. Therefore, the stability to moisture is increased, and hydrogen sulfide tends to be hardly generated.

  Lithium sulfide can be used without particular limitation, but high purity is preferred. Lithium sulfide can be produced, for example, by the methods described in JP-A-7-330312, JP-A-9-283156, JP-A 2010-163356, and Japanese Patent Application No. 2009-233892.

The lithium sulfide preferably has a total lithium oxide lithium salt content of 0.15% by mass or less, more preferably 0.1% by mass or less, and a lithium N-methylaminobutyrate content. The content is preferably 0.15% by mass or less, more preferably 0.1% by mass or less. When the total content of the lithium salt of sulfur oxide is 0.15% by mass or less, the solid electrolyte obtained by the melt quenching method or the mechanical milling method becomes a glassy electrolyte (fully amorphous). On the other hand, when the total content of the lithium salt of sulfur oxide exceeds 0.15% by mass, the obtained electrolyte may become a crystallized product from the beginning. The solid electrolyte that is a crystallized product before heat treatment may have low ionic conductivity and may not be expected to improve ionic conductivity due to heat treatment. The content of lithium N-methylaminobutyrate is 0.15% by mass When it is below, the degradation product of lithium N-methylaminobutyrate does not deteriorate the cycle performance of the lithium ion battery. When lithium sulfide with reduced impurities is used, a high ion conductive electrolyte can be obtained.

When lithium sulfide is produced based on the above-mentioned JP-A-7-330312 and JP-A-9-283156, it is preferable to purify the lithium sulfide because it contains a lithium salt of a sulfur oxide.
On the other hand, lithium sulfide produced by the method for producing lithium sulfide described in JP-A-2010-163356 may be used without purification because it contains a very small amount of sulfur oxide lithium salt or the like.
As a preferable purification method, for example, a purification method described in International Publication No. WO2005 / 40039 and the like can be mentioned. Specifically, the lithium sulfide obtained as described above is washed at a temperature of 100 ° C. or higher using an organic solvent.

  As long as diphosphorus pentasulfide is manufactured and sold industrially, it can be used without particular limitation.

  LiOH can be used without particular limitation as long as it is manufactured and sold industrially.

As specific manufacturing methods, a melt quench method, a mechanical milling method (MM method), a slurry method in which raw materials are reacted in an organic solvent, and a solution method will be described below. A sulfide-based solid electrolyte using Li ₂ S and P ₂ S ₅ as raw materials will be described.

(A) Melting and quenching method The melting and quenching method is described, for example, in JP-A-6-279049 and WO2005 / 119706. Specifically, a mixture of P ₂ S ₅ and Li ₂ S in a predetermined amount in a mortar and pelletized is placed in a carbon-coated quartz tube and vacuum-sealed. After reacting at a predetermined reaction temperature, a sulfide-based glass solid electrolyte is obtained by putting it in ice and rapidly cooling it.
The reaction temperature is preferably 400 ° C to 1000 ° C, more preferably 800 ° C to 900 ° C. Moreover, reaction time becomes like this. Preferably it is 0.1 to 12 hours, More preferably, it is 1 to 12 hours.
The quenching temperature of the reactant is usually 10 ° C. or less, preferably 0 ° C. or less, and the cooling rate is usually about 1 to 10,000 K / sec, preferably 10 to 10,000 K / sec.

(B) Mechanical milling method (MM method)
The MM method is described in, for example, JP-A-11-134937, JP-A-2004-348972, and JP-A-2004-348993.
Specifically, a predetermined amount of P ₂ S ₅ and Li ₂ S are mixed in a mortar and reacted for a predetermined time using, for example, various ball mills to obtain a sulfide-based glass solid electrolyte.
The MM method using the above raw materials can be reacted at room temperature. Therefore, there is an advantage that a glass solid electrolyte having a charged composition can be obtained without thermal decomposition of the raw material.
Further, the MM method has an advantage that the glass solid electrolyte can be made into fine powder simultaneously with the production of the glass solid electrolyte.

In the MM method, various types such as a rotating ball mill, a rolling ball mill, a vibrating ball mill, and a planetary ball mill can be used.
As conditions for the MM method, for example, when a planetary ball mill is used, the rotational speed may be set to several tens to several hundreds of revolutions / minute, and the treatment may be performed for 0.5 hours to 100 hours.
Further, as described in JP 2010-90003 A, balls of a ball mill may be used by mixing balls having different diameters. In addition, as described in JP2009-110920A or JP2009-2111950, an organic solvent may be added to the raw material to form a slurry, and this slurry may be subjected to MM treatment. As described in JP 2010-30889 A, the temperature in the mill during MM processing may be adjusted.
It is preferable that the raw material temperature during MM treatment be 60 ° C. or higher and 160 ° C. or lower.

(C) Slurry method The slurry method is described in WO2004 / 093099 and WO2009 / 047977.
Specifically, a sulfide-based glass solid electrolyte is obtained by reacting a predetermined amount of P ₂ S ₅ particles and Li ₂ S particles in an organic solvent for a predetermined time.
Here, as described in JP-A-2010-140893, in order to advance the reaction, the slurry containing the raw material may be reacted while being circulated between the bead mill and the reaction vessel. Further, as described in WO2009 / 047977, when the raw material lithium sulfide is pulverized in advance, the reaction can proceed efficiently. In addition, as described in Japanese Patent Application No. 2010-270191, in order to increase the specific surface area of the raw material lithium sulfide, a polar solvent having a solubility parameter of 9.0 or more (for example, methanol, diethyl carnate, acetonitrile) is used. It may be immersed for a predetermined time.

The reaction temperature is preferably 20 ° C. or higher and 80 ° C. or lower, more preferably 20 ° C. or higher and 60 ° C. or lower.
The reaction time is preferably 1 hour or longer and 16 hours or shorter, more preferably 2 hours or longer and 14 hours or shorter.

  It is preferable that the raw materials lithium sulfide and phosphorous pentasulfide be in a solution or slurry form by the addition of an organic solvent. Usually, the amount of the raw material (total amount) added to 1 liter of the organic solvent is about 0.001 kg or more and 1 kg or less. Preferably they are 0.005 kg or more and 0.5 kg or less, Most preferably, they are 0.01 kg or more and 0.3 kg or less.

The organic solvent is not particularly limited, but an aprotic organic solvent is particularly preferable.
Examples of the aprotic organic solvent include aprotic apolar organic solvents (for example, hydrocarbon-based organic solvents), aprotic polar organic compounds (for example, amide compounds, lactam compounds, urea compounds, organic sulfur compounds, cyclic compounds) An organic phosphorus compound or the like) can be suitably used as a single solvent or a mixed solvent.
As the hydrocarbon-based organic solvent, saturated hydrocarbons, unsaturated hydrocarbons, or aromatic hydrocarbons can be used as the hydrocarbon-based solvent that is the solvent.
Examples of the saturated hydrocarbon include hexane, pentane, 2-ethylhexane, heptane, decane, and cyclohexane.
Examples of the unsaturated hydrocarbon include hexene, heptene, cyclohexene and the like.
Aromatic hydrocarbons include toluene, xylene, decalin, 1,2,3,4-tetrahydronaphthalene and the like.
Of these, toluene and xylene are particularly preferable.

When a hydrocarbon solvent is used as the organic solvent, the hydrocarbon solvent is preferably dehydrated in advance. Specifically, the water content is preferably 100 ppm by weight or less, and particularly preferably 30 ppm by weight or less.
In addition, you may add another solvent to a hydrocarbon type solvent as needed. Specific examples include ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran, alcohols such as ethanol and butanol, esters such as ethyl acetate, and halogenated hydrocarbons such as dichloromethane and chlorobenzene.

(D) Solution method This is a method of reacting in a state in which raw materials are considerably dissolved by using a solvent having higher polarity than the slurry method, and is described in US Published Patent Application US2013 / 0295469.
Tetrahydrofuran or the like is used as the solvent.
Manufacturing conditions such as temperature conditions, processing time, and charge for the melt quenching method, MM method and slurry method can be appropriately adjusted according to the equipment used.

The manufacturing method of the crystalline solid electrolyte (glass ceramic) may be based on JP2005-228570, WO2007 / 065539, and JP2002-109955.
Specifically, the sulfide-based solid electrolyte (glass) obtained above is heat-treated at a predetermined temperature to generate sulfide-based crystallized glass (glass ceramics).
The heat treatment is preferably performed in an environment having a dew point of −40 ° C. or lower, more preferably in an environment having a dew point of −60 ° C. or lower. The pressure at the time of heating may be a normal pressure or a reduced pressure. The atmosphere may be air or an inert atmosphere.
In addition to the above, heating may be performed in a solvent as described in JP2010-186744A.
The heat treatment temperature is higher than the glass transition temperature, preferably higher than the crystallization temperature. The crystallization temperature is usually 100 ° C to 300 ° C.
The heat treatment time is preferably 0.1 hours or more and 240 hours or less. More preferably, it is 1-10 hours, More preferably, it is 1-5 hours.
When the heat treatment time is shorter than 0.1 hour, it may be difficult to obtain a crystallized glass with a high degree of crystallinity, and when it is longer than 240 hours, a crystallized glass with a low degree of crystallinity may be generated.
If the sulfide solid electrolyte is a powder, the heat treatment may be performed while stirring. Moreover, you may carry out, pressurizing.

  The solid electrolyte of the present invention can be used for a solid electrolyte layer and an electrode (a positive electrode layer and / or a negative electrode layer) of an all-solid lithium secondary battery. Moreover, it can mix with an electrode material and can manufacture a compound material. When mixed with a positive electrode material (positive electrode active material), it becomes a positive electrode mixture, and when mixed with a negative electrode material (negative electrode active material), it becomes a negative electrode mixture.

As the positive electrode material, known materials can be used. For example, V ₂ O ₅ , LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , Li (Ni _a Co _b Mn _c ) O ₂ (where 0 < a <1, 0 <b <1, 0 <c <1, a + b + c = 1), LiNi _1-Y Co _{Y 2} O ₂ , LiCo _1-Y Mn _{Y 2} O ₂ , LiNi _1-Y Mn _{Y 2} O ₂ (where , 0 ≦ Y <1), Li (Ni _a Co _b Mn _c ) O ₄ (0 <a <2, 0 <b <2, 0 <c <2, a + b + c = 2), LiMn _2−Z Ni _Z O _{4, LiMn 2-Z Co Z} O 4 ( where, 0 _{<Z <2),} include LiCoPO _4, LiFePO 4.

Further, for example, as sulfides, oxides such as titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), iron sulfide (FeS, FeS ₂ ), copper sulfide (CuS), nickel sulfide (Ni ₃ S ₂ ), etc. As systems, bismuth oxide (Bi ₂ O ₃ ), bismuth leadate (Bi ₂ Pb ₂ O ₅ ), copper oxide (CuO), vanadium oxide (V ₆ O ₁₃ ), lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ) and the like can be used.
In addition to the above, niobium selenide (NbSe ₃ ), organic disulfide compounds, carbon sulfide compounds, sulfur, indium metal, and the like can be used.

  As the negative electrode material, known materials can be used. For example, carbon materials, specifically, artificial graphite, graphite carbon fiber, resin-fired carbon, pyrolytic vapor-grown carbon, coke, mesocarbon microbeads (MCMB), Examples include furfuryl alcohol resin-fired carbon, polyacene, pitch-based carbon fiber, vapor-grown carbon fiber, natural graphite, and non-graphitizable carbon. Also, an alloy in combination with a metal itself such as metallic lithium, metallic indium, metallic aluminum, metallic silicon, or another element or compound can be used as the negative electrode material.

Production Example 1 (Production of high purity lithium sulfide)
Production of high-purity lithium sulfide was carried out in the same manner as in the examples of International Publication WO2005 / 040039A1. Specifically, it was performed as follows.
(1) Production of lithium sulfide (Li ₂ S) Lithium sulfide was produced according to the method of the first aspect (two-step method) of JP-A-7-330312. Specifically, N-methyl-2-pyrrolidone (NMP) 3326.4 g (33.6 mol) and lithium hydroxide 287.4 g (12 mol) were charged into a 10 liter autoclave equipped with a stirring blade, and 300 rpm, 130 The temperature was raised to ° C. After the temperature rise, hydrogen sulfide was blown into the liquid at a supply rate of 3 liters / minute for 2 hours.
Subsequently, this reaction solution was heated in a nitrogen stream (200 cc / min) to dehydrosulfide a part of the reacted hydrogen sulfide. As the temperature increased, water produced as a by-product due to the reaction between hydrogen sulfide and lithium hydroxide started to evaporate, but this water was condensed by the condenser and extracted out of the system. While water was distilled out of the system, the temperature of the reaction solution rose, but when the temperature reached 180 ° C., the temperature increase was stopped and the temperature was kept constant. After the dehydrosulfurization reaction was completed (about 80 minutes), the reaction was completed to obtain lithium sulfide.

(2) Purification of lithium sulfide After decanting NMP in the 500 mL slurry reaction solution (NMP-lithium sulfide slurry) obtained in (1) above, 100 mL of dehydrated NMP was added and stirred at 105 ° C. for about 1 hour. . NMP was decanted at that temperature. Further, 100 mL of NMP was added, stirred at 105 ° C. for about 1 hour, NMP was decanted at that temperature, and the same operation was repeated a total of 4 times. After completion of the decantation, lithium sulfide was dried at 230 ° C. (temperature higher than the boiling point of NMP) under a nitrogen stream for 3 hours under normal pressure. The impurity content in the obtained lithium sulfide was measured.

Incidentally, lithium sulfite _(Li 2 _SO 3), the content of each sulfur oxide lithium sulfate _(Li 2 SO ₄₎ and lithium thiosulfate _{(Li 2 S 2 O 3)} , and N- methylamino acid lithium (LMAB) Was quantified by ion chromatography. As a result, the total content of sulfur oxides was 0.13% by mass, and LMAB was 0.07% by mass.

Example 1
[92.6 (0.794Li ₂ S / 0.206P ₂ S ₅ ) · 7.4 LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 79.4: 20.6: 7.9]
0.4322 g (9.406 mmol) of high-purity lithium sulfide produced in Production Example 1, 0.5451 g (2.452 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0227 g (0.9479 mmol) of LiOH were mixed well. The mixed powder and 10 zirconia balls having a diameter of 10 mm are put into a planetary ball mill (Fritsch: Model No. P-7) alumina pot and completely sealed, and the alumina pot is filled with nitrogen, and a nitrogen atmosphere I made it.
For the first 10 minutes, the planetary ball mill was rotated at a low speed (100 rpm), and lithium sulfide, diphosphorus pentasulfide, and LiOH were sufficiently mixed. Thereafter, the rotational speed of the planetary ball mill was gradually increased to 370 rpm. Mechanical milling was performed for 40 hours at a rotation speed of the planetary ball mill at 370 rpm to obtain sulfide glass as a white yellow powder.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 222 degreeC when the crystallization temperature of this sulfide glass was measured by TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 2.5 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 232 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a high ion conductive crystal (thiolysicon type II crystal). The ionic conductivity of the obtained glass ceramic was 1.0 × 10 ⁻³ S / cm.

Ionic conductivity was measured by the following method.
The solid electrolyte was filled in a tablet molding machine, and a pressure of 22 MPa was applied to obtain a molded body. Furthermore, carbon was placed on both surfaces of the molded body as an electrode, and pressure was again applied with a tablet molding machine to produce a molded body for measuring conductivity (diameter: about 10 mm, thickness: about 1 mm). The molded body was subjected to ionic conductivity measurement by AC impedance measurement. The conductivity value was a value at 25 ° C.

Example 2
[95.5 (0.797Li ₂ S / 0.203P ₂ S ₅ ) · 4.5LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 79.7: 20.3: 4.71]
Using 0.4413 g (9.603 mmol) of the high purity lithium sulfide produced in Production Example 1, 0.5451 g (2.452 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0137 g (0.5700 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Example 1.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). The crystallization temperature of this sulfide glass was measured by TG-DTA measurement and found to be 231 ° C. Moreover, the ionic conductivity of the obtained sulfide glass was 3.1 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 241 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder is confirmed by X-ray measurement (XRD measurement), and is a crystal different from only a low ion conductive crystal (thiolithicone type III crystal) and a high ion conductive crystal (thiolithicone type II crystal). It was confirmed to have a structure. The ionic conductivity of the obtained glass ceramic was 1.0 × 10 ⁻³ S / cm.

Example 3
_{[98.5 (0.8Li 2 S / 0.2P} 2 S 5) · 1.5LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 80.0: 20.0: 1.52]
Using 0.4504 g (9.803 mmol) of high-purity lithium sulfide produced in Production Example 1, 0.5451 g (2.452 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0045 g (0.1879 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Example 1.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 238 degreeC when the crystallization temperature of this sulfide glass was measured by TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 4.1 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put into a Schlenk tube, placed in an oil bath at 248 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a low ion conductive crystal (thiolysicon type III crystal). The ionic conductivity of the obtained glass ceramics was 3.2 × 10 ⁻⁴ S / cm.

Reference example 1
[95 (0.75Li ₂ S / 0.25P ₂ S ₅ ) · 5LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 75.0: 25.0: 5.26]
0.3796 g (8.23 mmol) of high-purity lithium sulfide produced in Production Example 1, 0.6066 g (2.729 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0137 g (0.572 mmol) of LiOH were mixed well. The mixed powder and 10 zirconia balls having a diameter of 10 mm are put into a planetary ball mill (Fritsch: Model No. P-7) alumina pot and completely sealed, and the alumina pot is filled with nitrogen, and a nitrogen atmosphere I made it.
For the first 10 minutes, the planetary ball mill was rotated at a low speed (100 rpm), and lithium sulfide, diphosphorus pentasulfide, and LiOH were sufficiently mixed. Thereafter, the rotational speed of the planetary ball mill was gradually increased to 370 rpm. Mechanical milling was performed for 40 hours at a rotation speed of the planetary ball mill at 370 rpm to obtain sulfide glass as a white yellow powder.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). The crystallization temperature of this sulfide glass was measured by TG-DTA measurement and found to be 234 ° C. Moreover, the ionic conductivity of the obtained sulfide glass was 4.6 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 234 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement). It was confirmed that it had a crystal structure different from that of only the low ion conductive crystal (thiolithicone type III crystal) and only the high ion conductive crystal (thiolithicone type II crystal). The ionic conductivity of the obtained glass ceramics was 6.5 × 10 ⁻⁴ S / cm.

Reference example 2
[93 (0.75Li ₂ S / 0.25P ₂ S ₅ ) · 7LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 75.0: 25.0: 7.53]
Using 0.3774 g (8.214 mmol) of the high-purity lithium sulfide produced in Production Example 1, 0.6031 g (2.713 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0195 g (0.814 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Reference Example 1.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 227 degreeC when the crystallization temperature of this sulfide glass was measured by TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 3.9 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put into a Schlenk tube, placed in an oil bath at 227 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a high ion conductive crystal (thiolysicon type II crystal). The ionic conductivity of the obtained glass ceramic was 1.3 × 10 ⁻³ S / cm.

Reference example 3
[90 (0.75Li ₂ S / 0.25P ₂ S ₅ ) · 10LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 75.0: 25.0: 11.1]
Using 0.3739 g (8.138 mmol) of the high purity lithium sulfide produced in Production Example 1, 0.5975 g (2.688 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0286 (1.194 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Reference Example 1.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 219 degreeC when the crystallization temperature of this sulfide glass was measured by TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 2.8 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put into a Schlenk tube, placed in an oil bath at 219 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a high ion conductive crystal (thiolysicon type II crystal). The ionic conductivity of the obtained glass ceramics was 9.6 × 10 ⁻⁴ S / cm.

Reference example 4
[85 (0.75Li ₂ S / 0.25P ₂ S ₅ ) · 15LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 75.0: 25.0: 17.6]
Using 0.3677 g (8.003 mmol) of high-purity lithium sulfide produced in Production Example 1, 0.5876 g (2.644 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0446 g (1.862 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Reference Example 1.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 208 degreeC when the crystallization temperature of this sulfide glass was measured by the TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 2.0 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 208 ° C. and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a high ion conductive crystal (thiolysicon type II crystal). The ionic conductivity of the obtained glass ceramics was 3.9 × 10 ⁻⁴ S / cm.

Reference Example 5
[96.9 (0.75 Li ₂ S / 0.25P ₂ S ₅ ) · 3.1 LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 75.0: 25.0: 3.20]
Using 0.3817 g (8.307 mmol) of high-purity lithium sulfide produced in Production Example 1, 0.6099 g (2.744 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0084 g (0.3507 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Reference Example 1.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). The crystallization temperature of this sulfide glass was measured by TG-DTA measurement and found to be 231 ° C. Moreover, the ionic conductivity of the obtained sulfide glass was 5.1 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 231 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a low ion conductive crystal (thiolysicon type III crystal). The ionic conductivity of the obtained glass ceramics was 5.7 × 10 ⁻⁴ S / cm.

Example 4
[97 (0.80Li ₂ S / 0.20P ₂ S ₅ ) · 3LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 80.0: 20.0: 3.09]
0.4508 g (9.811 mmol) of high purity lithium sulfide produced in Production Example 1, 0.5402 g (2.430 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0090 g (0.3758 mmol) of LiOH were mixed well. The mixed powder and 10 zirconia balls having a diameter of 10 mm are put into a planetary ball mill (Fritsch: Model No. P-7) alumina pot and completely sealed, and the alumina pot is filled with nitrogen, and a nitrogen atmosphere I made it.
For the first 10 minutes, the planetary ball mill was rotated at a low speed (100 rpm), and lithium sulfide, diphosphorus pentasulfide, and LiOH were sufficiently mixed. Thereafter, the rotational speed of the planetary ball mill was gradually increased to 370 rpm. Mechanical milling was performed for 40 hours at a rotation speed of the planetary ball mill at 370 rpm to obtain sulfide glass as a white yellow powder.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). The crystallization temperature of this sulfide glass was measured by TG-DTA measurement and found to be 234 ° C. Moreover, the ionic conductivity of the obtained sulfide glass was 3.7 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 234 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement). It was confirmed that it had a crystal structure different from that of only the low ion conductive crystal (thiolithicone type III crystal) and only the high ion conductive crystal (thiolithicone type II crystal). The ionic conductivity of the obtained glass ceramic was 7.5 × 10 ⁻⁴ S / cm.

Example 5
[95 (0.80Li ₂ S / 0.20P ₂ S ₅ ) · 5LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 80.0: 20.0: 5.26]
Using 0.4479 g (9.748 mmol) of high-purity lithium sulfide produced in Production Example 1, 0.5369 g (2.415 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0152 g (0.6347 mmol) of LiOH are used. Except for this, a sulfide glass was obtained in the same manner as in Example 4.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 230 degreeC when the crystallization temperature of this sulfide glass was measured by TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 3.1 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 230 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement). It was confirmed that it had a crystal structure different from that of only the low ion conductive crystal (thiolithicone type III crystal) and only the high ion conductive crystal (thiolithicone type II crystal). The ionic conductivity of the obtained glass ceramic was 9.3 × 10 ⁻⁴ S / cm.

Example 6
[93 (0.80Li ₂ S / 0.20P ₂ S ₅ ) · 7LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 80.0: 20.0: 7.53]
Using 0.4450 g (9.685 mmol) of high-purity lithium sulfide produced in Production Example 1, 0.5334 g (2.400 mmol) of phosphorous pentasulfide (manufactured by Thermophos), and 0.0216 (0.9019 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Example 4.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 222 degreeC when the crystallization temperature of this sulfide glass was measured by TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 2.4 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 222 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a high ion conductive crystal (thiolysicon type II crystal). The ionic conductivity of the obtained glass ceramics was 7.9 × 10 ⁻⁴ S / cm.

Example 7
[90 (0.80Li ₂ S / 0.20P ₂ S ₅ ) · 10LiOH]
[Li ₂ S: P ₂ S ₅ : LiOH = 80.0: 20.0: 11.1]
Using 0.4405 g (9.587 mmol) of the high purity lithium sulfide produced in Production Example 1, 0.5279 g (2.375 mmol) of diphosphorus pentasulfide (manufactured by Thermophos), and 0.0316 (1.319 mmol) of LiOH Except for this, a sulfide glass was obtained in the same manner as in Example 4.

Vitrification (sulfide glass) of the white yellow powder obtained by the mechanical milling treatment was confirmed by X-ray measurement (XRD measurement). It was 214 degreeC when the crystallization temperature of this sulfide glass was measured by TG-DTA measurement. Moreover, the ionic conductivity of the obtained sulfide glass was 1.7 × 10 ⁻⁴ S / cm.
1.0 g of the obtained sulfide glass was put in a Schlenk tube, placed in an oil bath at 214 ° C., and subjected to vacuum heat treatment for 2 hours to obtain glass ceramics. Crystallization of the obtained powder was confirmed by X-ray measurement (XRD measurement), and it was confirmed that it had a high ion conductive crystal (thiolysicon type II crystal). The ionic conductivity of the obtained glass ceramics was 5.6 × 10 ⁻⁴ S / cm.

  The battery using the solid electrolyte of the present invention can be used as a battery for a portable information terminal, a portable electronic device, a small household power storage device, a motorcycle using a motor as a power source, an electric vehicle, a hybrid electric vehicle, or the like.

Claims (19)

Li, wherein P, S, O, and H, the molar ratio of each element meets the following formulas (1) to (5), wherein the O and H is derived from LiOH, solid electrolyte.
Li: P: S: O: H = (160 + 2k + L) :( 40-2k) :( 180-4k): M: N (1)
−1.5 ≦ k ≦ 1.5 (2)
0 ≦ L ≦ M + N (3)
2 ≦ M ≦ 60 (4)
2 ≦ N ≦ 60 (5) Wherein li, P, S, O, and H, the molar ratio of each element meets the following formulas (1) to (5), wherein the O and H are those derived from LiOH,
Wherein Li, P, S, O, and _H, Li _{2 S,} when converted with _{P 2 S 5, LiOH, Li} 2 S, the molar ratio of P 2 S 5, LiOH, formula (6), (2) Solid electrolyte satisfying (4) .
Li: P: S: O: H = (160 + 2k + L) :( 40-2k) :( 180-4k): M: N (1)
−1.5 ≦ k ≦ 1.5 (2)
0 ≦ L ≦ M + N (3)
0 <M ≦ 100 (4)
0 <N ≦ 100 (5)
Li ₂ S: P ₂ S ₅ : LiOH = (80 + k) :( 20−k): M (6)   Furthermore, the solid electrolyte of Claim 1 or 2 containing a halogen element.   The solid electrolyte according to claim 1 or 2, comprising only Li, P, S, O, and H elements.   The solid electrolyte according to any one of claims 1 to 4, which is an amorphous solid electrolyte.   The solid electrolyte according to claim 1, which is a crystalline solid electrolyte.   The solid electrolyte according to claim 6, wherein the crystal is a thiolithicone type II crystal.   The solid electrolyte according to claim 6 or 7, which has a crystallinity of 30% to 99%.   Formula (2) is -1.0 <= k <= 1.0, The solid electrolyte in any one of Claims 1-8. The solid electrolyte according to claim 1, wherein the formula (3) satisfies 0 ≦ L ≦ M and 0 ≦ L ≦ N. Equation (4) is, 0 <a solid electrolyte according to any one of claims 2-10 is M ≦ 60.   The solid electrolyte according to claim 11, wherein the formula (4) satisfies 2 ≦ M ≦ 60. Equation (5) is, 0 <N ≦ 60 at which claims 2-12 solid electrolyte according to any one of.   The solid electrolyte according to claim 13, wherein the formula (5) satisfies 2 ≦ N ≦ 60. The solid electrolyte according to any one of claims 1 to 14 , wherein the volume-based average particle diameter is from 0.01 µm to 100 µm. Li ₂ S, by reacting a phosphorus compound and LiOH, to produce the solid electrolyte according to any one of claims 1 to 15, a manufacturing method of the solid electrolyte. The method for producing a solid electrolyte according to claim 16 , wherein the phosphorus compound is P ₂ S ₅ . The solid electrolyte layer containing the solid electrolyte in any one of Claims 1-15 . Including a positive electrode layer, a solid electrolyte layer, and a negative electrode layer;
The positive electrode layer, the solid electrolyte layer, and the battery at least one layer comprising a solid electrolyte according to any one of claims 1 to 15 out of the negative electrode layer.