JP2014028717A - Solid electrolyte - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolyte with high ion conductivity, using an ion other than a lithium ion as a conduction species.SOLUTION: A solid electrolyte includes one or more element selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium and radium, a phosphorus element, a sulfur element, and a halogen element.

Description

  The present invention relates to a halogen-containing sulfide-based solid electrolyte having ions other than lithium ions as conductive species.

In recent years, demand for secondary batteries used in portable information terminals, portable electronic devices, small household electric power storage devices, motor-driven motorcycles, electric vehicles, hybrid electric vehicles, and the like has increased.
There is a lithium ion battery as a high-capacity secondary battery. However, since the lithium ion battery is an electrolyte containing an organic solvent, there is a risk of liquid leakage and a risk of ignition.

In order to solve such problems, various studies have been conducted on sulfide-based solid electrolytes, and sulfide-based solid electrolytes having high ionic conductivity have been developed (Patent Document 1).
However, since the sulfide-based solid electrolyte described in Patent Document 1 requires a large amount of lithium, there is a possibility that a lithium source as a raw material will be insufficient with an increase in demand for lithium ion batteries in the future.

As a means for solving the problem of the shortage of raw materials, a sodium-based solid electrolyte using sodium rich in raw materials as a conductive species has been developed (Non-patent Document 1). However, the solid electrolyte described in Non-Patent Document 1 is not practically sufficient in ionic conductivity (about 2 × 10 ⁻⁴ Scm ⁻¹ at room temperature (25 ° C.)), and further improvement in ionic conductivity is necessary. there were.

JP 2005-228570 A

The world's first successful operation of an all-solid-state sodium storage battery at room temperature-a major step in the research and development of highly safe next-generation storage batteries-(http://www.jst.go.jp/pr/announce/20120523/index.html )

  An object of the present invention is to provide a solid electrolyte having high ionic conductivity using ions other than lithium ions as a conductive species.

According to the present invention, the following solid electrolyte and the like are provided.
1. A solid electrolyte containing one or more elements selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium and radium, a phosphorus element, a sulfur element, and a halogen element.
2. The solid electrolyte according to 1, which satisfies the following formula (1).
_{L a M b P c S d} X e ... (1)
(In the formula, L is one or more elements selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba and Ra.
M is one or more elements selected from B, Al, Si, Ge, Ga, In, As, Se, Sn, Sb, Te, Pb, and Bi.
X is one or more halogen elements selected from F, Cl, Br, I, and At.
a to e indicate the composition ratio of each element, and 0.1 <a ≦ 15, 0 ≦ b ≦ 3, 0 <c ≦ 5, 0 <d ≦ 15, and 0.1 <e ≦ 3. )
3. 3. The solid electrolyte according to 2, wherein b in the formula (1) is 0 and c is 1.
4). 4. The solid electrolyte according to 2 or 3, wherein 0.5 ≦ d ≦ 4 in the formula (1).
5. Solid electrolyte in any one of 1-4 whose ionic conductivity in 25 degreeC is 3 * 10 < ^-4 > Scm < ^-1 > or more.
6). Any one selected from phosphorus sulfide, sulfur and phosphorus, phosphorus sulfide and sulfur, and phosphorus sulfide, sulfur and phosphorus;
The solid electrolyte in any one of 1-5 obtained using the compound represented by following formula (2), and the compound represented by following formula (3).
Q _w X _x (2)
(In the formula (2), Q is Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, B, Al, Si, P, S, Ge, Ga, In, As, One or more selected from Se, Sn, Sb, Te, Pb, and Bi.
w is any integer of 1 to 4, and x is any integer of 1 to 10.
X is one or more halogen elements selected from F, Cl, Br, I, and At. )
L _y S (3)
(In Formula (3), L is 1 or more selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra.
y is 0.5-4. )
7). 7. The solid electrolyte according to 6, wherein Q in the formula (2) is P and X in the formula (2) is Br, I or Cl.
8). 7. The Q in the formula (2) is Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba or Ra, and the X in the formula (2) is Br, I or Cl Solid electrolyte.
The electrolyte sheet containing the solid electrolyte in any one of 9.1-8.
An electrolyte sheet manufactured from the solid electrolyte according to any one of 10.1 to 8.
11. An electrode sheet comprising the solid electrolyte according to any one of 1 to 8.
12. An electrode sheet produced from the solid electrolyte according to any one of 1 to 8.
13. A secondary battery comprising the solid electrolyte according to any one of 1 to 8.
The secondary battery manufactured from the solid electrolyte in any one of 14.1-8.

  According to the present invention, it is possible to provide a solid electrolyte having high ionic conductivity using ions other than lithium ions as a conductive species.

It is a figure which shows an example of a Cole-Cole plot. It is a schematic block diagram of the measuring apparatus of hydrogen sulfide concentration average value It is a figure which shows an example of the relationship between wet air distribution time and hydrogen sulfide concentration. It is a figure which shows an example of the manufacturing apparatus which can be used by the improved slurry method. It is a figure which shows another example of the manufacturing apparatus which can be used by a slurry method.

[Solid electrolyte]
The solid electrolyte of the present invention contains one or more elements selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium, and radium, a phosphorus element, a sulfur element, and a halogen element.
The solid electrolyte of the present invention is a solid electrolyte that does not use lithium as a conductive species, and can exhibit high ionic conductivity by containing a halogen element.

One or more elements selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium and radium contained in the solid electrolyte are preferably selected from sodium, potassium, rubidium, cesium, francium and beryllium One or more elements selected from the group consisting of sodium and potassium, more preferably sodium.
The halogen element contained in the solid electrolyte is preferably one or more halogen elements selected from fluorine, chlorine, bromine and iodine, more preferably one or more halogen elements selected from chlorine, bromine and iodine, One or more halogen elements selected from chlorine and bromine are preferred.

The solid electrolyte of the present invention is substantially composed of one or more elements selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium and radium, phosphorus element, sulfur element, and halogen element. And may contain other elements within the range not impairing the effects of the present invention.
Examples of the other elements include Ge, Si, Al, Ga, Al, B, In, As, Se, Sn, Sb, Te, Pb, and Bi.
Moreover, although lithium may be contained as another element, the one where content of lithium is small is preferable.

The solid electrolyte of the present invention is preferably a solid electrolyte represented by the following formula (1).
_{L a M b P c S d} X e ... (1)
(In the formula, L is one or more elements selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba and Ra.
M is one or more elements selected from B, Al, Si, Ge, Ga, In, As, Se, Sn, Sb, Te, Pb, and Bi.
X is one or more halogen elements selected from F, Cl, Br, I and At.
a to e indicate the composition ratio of each element, and 0.1 <a ≦ 15, 0 ≦ b ≦ 3, 0 <c ≦ 5, 0 <d ≦ 15, and 0.1 <e ≦ 3. )

Formula (1) L is preferably one or more elements selected from Na, K, Rb, Cs, Fr, and Be, more preferably one or more elements selected from Na and K, and more preferably Is Na.
M is preferably one or more elements selected from B, Si, Ge and Al, more preferably one or more elements selected from Ge, Si and B.
X is preferably one or more halogen elements selected from F, Cl, Br and I, more preferably one or more halogen elements selected from Cl, Br and I, and still more preferably Cl and One or more halogen elements selected from Br.

The composition ratio of L, M, P, S and X in formula (1) is as follows:
0.1 <a ≦ 15, preferably 0.2 ≦ a ≦ 13, and more preferably 0.3 ≦ a ≦ 12.
0 ≦ b ≦ 3, preferably 0 ≦ b ≦ 3, more preferably 0 ≦ b ≦ 2, and most preferably b is 0.
0 <c ≦ 5, preferably 0.5 ≦ c ≦ 4, more preferably 0.8 ≦ c ≦ 4, and most preferably c is 1.
0 <d ≦ 15, preferably 0.5 ≦ d ≦ 15, more preferably 0.5 ≦ d ≦ 13, and most preferably 0.5 ≦ d ≦ 12.
0.1 <e ≦ 3, preferably 0.1 ≦ e ≦ 2, and more preferably 0.2 ≦ e ≦ 2.

In the formula (1), b is preferably 0 and c is 1.
In the formula (1), preferably 0.5 ≦ d ≦ 4.

The solid electrolyte may be crystallized or amorphous. If the crystal has higher ionic conductivity than amorphous, the ionic conductivity of the electrolyte layer and electrode layer can be increased by crystallization. If amorphous, the crystal is softer than the crystal. The contact state between the solid electrolytes and the contact state with the active material and the conductive auxiliary agent can be improved.
Here, the crystal structure is preferably a Na ₃ PS ₄ crystal structure. This is because the ionic conductivity can be increased.

The shape of the solid electrolyte is not particularly limited, and may be a particle shape or a sheet shape.
When the solid electrolyte is in the form of particles, the electrolyte layer can be produced by applying a slurry containing the solid electrolyte when forming the electrolyte layer. When manufacturing an electrolyte sheet using a solid electrolyte, after forming an electrolyte layer, it may be heated under predetermined heating conditions described later.
Moreover, an electrolyte layer can also be manufactured using an electrostatic method.

  When the solid electrolyte of the present invention is in the form of particles, the volume-based average particle diameter (Mean Volume Diameter, hereinafter referred to as “particle diameter”) is preferably 0.01 μm or more and 500 μm or less, more preferably 0.8 μm or less. It is from 0.5 μm to 300 μm, and more preferably from 0.1 μm to 200 μm.

  The particle size of the solid electrolyte is preferably measured by a laser diffraction particle size distribution measurement method. The laser diffraction particle size distribution measuring method can measure the particle size distribution without drying the composition. In the laser diffraction particle size distribution measuring method, a particle size distribution is measured by irradiating a particle group in a composition with a laser and analyzing the scattered light.

The particle size of the solid electrolyte may be measured using a dried solid electrolyte or a sulfide-based glass that is a precursor thereof. As a measurement example, a laser diffraction particle size distribution measuring apparatus (Mastersizer manufactured by Malvern Instruments Ltd.) 2000) will be described.
First, 110 ml of dehydrated toluene (Wako Pure Chemicals, product name: special grade) was placed in the dispersion tank of the apparatus, and 6% of dehydrated tertiary butyl alcohol (Wako Pure Chemicals, special grade) was added as a dispersant. Added.
After sufficiently mixing the above mixture, the “dry solid electrolyte or precursor thereof” to be measured is added and the particle size is measured. The addition amount of the measurement object is adjusted and added so that the laser scattering intensity corresponding to the particle concentration falls within the specified range (10 to 20%) on the operation screen specified by the master sizer 2000. If this range is exceeded, multiple scattering may occur, and an accurate particle size distribution may not be obtained. On the other hand, when the amount is less than this range, the SN ratio is deteriorated, and there is a possibility that accurate measurement cannot be performed. In the master sizer 2000, the laser scattering intensity is displayed based on the addition amount of the measurement target. Therefore, the addition amount that falls within the laser scattering intensity may be found.
Although the optimum amount of the measurement target varies depending on the type of the ion conductive substance, etc., it is about 0.01 to 0.05 g.

The solid electrolyte is preferably an ion conductivity at 25 ° C. is at 2 × ¹⁰ -4 ^{Scm -1} or more, more preferably 3 × ¹⁰ -4 ^{Scm -1} or more, more preferably 4 × ¹⁰ -4 Scm ^-1 or more.

The ionic conductivity (σ) can be measured by the following procedure.
First, a solid electrolyte sample is formed into a shape having a cross section of 10 mmφ (cross sectional area S = 0.785 cm ² ) and a height (L) of 0.1 to 0.3 cm. Electrode terminals are taken from the upper and lower sides of the sample piece and measured by the AC impedance method (frequency range: 5 MHz to 0.5 Hz, amplitude: 10 mV) to obtain a Cole-Cole plot. FIG. 1 shows an example of a Cole-Cole plot. In the vicinity of the right end of the arc observed in the high-frequency region, the real part Z ′ (Ω) at the point where −Z ″ (Ω) is minimized is defined as the bulk resistance R (Ω) of the electrolyte. The conductivity σ (S / cm) is calculated.
R = ρ (L / S)
σ = 1 / ρ
In addition, when the lead distance from the sample one end surface to the measuring instrument is long, only a part of the right end of the arc may be observed, but the bulk resistance R (Ω) is determined according to the above method. In addition, there is a case where no arc is observed and -Z ″ (Ω) monotonously increases from around 0Ω. In this case, Z ′ (Ω) when −Z ″ (Ω) = 0 is set as the bulk resistance R (Ω).
The distance between the leads may be measured as about 60 cm.

In the solid electrolyte of the present invention, the average value of hydrogen sulfide concentration in the surrounding environment when left for 60 minutes in a stream of wet air is preferably 200 ppm or less, more preferably 150 ppm or less, and even more preferably 100 ppm or less. .
The average value of hydrogen sulfide concentration is an index indicating hydrolysis resistance. In general, a sulfide-based solid electrolyte generates hydrogen sulfide when hydrolyzed, but the solid electrolyte of the present invention can suppress hydrolysis, so that Less hydrogen sulfide is generated.

The average value of the hydrogen sulfide concentration of the solid electrolyte can be evaluated by the following hydrolysis test.
FIG. 2 is a schematic configuration diagram of an apparatus for measuring the hydrogen sulfide concentration average value.
As the measurement sample 11, a sample that has been well pulverized in a mortar in a nitrogen glow box with a dew point of −80 ° C. is used. A measurement sample 11 is sealed in a Schlenk bottle 12 of 0.1 g and 100 ml.
Next, air (wet air) humidified by passing the water tank 14 is circulated in the Schlenk bottle 12 at 500 ml / min. The temperature of the wet air is about 25 ° C. and the humidity is 80 to 90%. The supply amount of air is controlled by the flow meter 13.
The gas discharged from the Schlenk bottle 12 within 1 minute to 1 minute 45 seconds after the start of distribution is collected from the gas collection unit 15 and used as the first sample gas for measurement. For gases other than those collected, hydrogen sulfide is removed with a sodium hydroxide aqueous solution at the trap 16.
Using TS-100 manufactured by Mitsubishi Chemical Analytech, the sulfur content is quantified by the ultraviolet fluorescence method, and the hydrogen sulfide concentration of the sample gas is calculated. When the sample gas was qualitatively analyzed with a gas chromatograph using an Agilent 6890 (with a sulfur selective detector (SIEVERS 355)), it was confirmed that the sulfur content was 99% or more of hydrogen sulfide gas.
From the Schlenk bottle 5 minutes to 5 minutes 45 seconds after the start of distribution, 10 minutes to 10 minutes 45 seconds after the start of distribution, 20 minutes to 20 minutes 45 seconds after the start of distribution, 60 minutes to 60 minutes 45 seconds after the start of distribution The discharged gas is also measured in the same manner as the first sample gas.
The hydrogen sulfide concentration average value (ppm) is obtained from the hydrogen sulfide concentration and the measurement time.
FIG. 3 shows an example of the relationship between the wet air circulation time and the hydrogen sulfide concentration. The curve is obtained by smoothing each measurement point, and the area (ppm · min) surrounded by the curve, the vertical axis and the horizontal axis is divided by 60 minutes to obtain the hydrogen sulfide concentration average value (ppm).

For example, the following first to third production methods can be used for the solid electrolyte of the present invention depending on the timing of using, for example, a compound containing a halogen element as a raw material (hereinafter sometimes referred to as a halogen compound).
Hereinafter, although the manufacturing method of the solid electrolyte of this invention is demonstrated, it cannot be overemphasized that the manufacturing method of the solid electrolyte of this invention is not limited to the following manufacturing method.

[First manufacturing method of solid electrolyte]
(1) Raw material The solid electrolyte of this invention can be manufactured by using the following (a) component, (b) component, and (c) component as a raw material.
(A) Component: any one selected from phosphorus sulfide, sulfur and phosphorus, phosphorus sulfide and sulfur, and phosphorus sulfide, sulfur and phosphorus. (B) Component: Compound represented by the following formula (2) Q _w X _x (2)
(In the formula (2), Q is Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, B, Al, Si, P, S, Ge, Ga, In, As, One or more elements selected from Se, Sn, Sb, Te, Pb and Bi.
w is any integer of 1 to 4, and x is any integer of 1 to 10.
X is one or more halogen elements selected from F, Cl, Br, I, and At. )
(C) Component: Compound represented by the following formula (3) L _y S (3)
(In Formula (3), L is 1 or more selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra.
y is 0.5-4. )

In the formula (2), Q is sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium, radium, boron, aluminum, silicon, phosphorus, sulfur, germanium, gallium, indium, arsenic, One or more elements selected from selenium, tin, antimony, tellurium, lead, bismuth, preferably selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium, radium and phosphorus One or more elements selected from sodium, potassium and phosphorus, more preferably one or more elements selected from sodium and phosphorus.
w is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and most preferably 1.
X is one or more halogen elements selected from fluorine, chlorine, bromine, iodine and astatine, preferably fluorine, chlorine, bromine or iodine, more preferably chlorine, bromine or iodine, still more preferably chlorine Or it is bromine.
x is any integer of 1 to 10, preferably any one of 1 to 9, more preferably any one of 1 to 7, and preferably 1 or 3.

Specific examples of the compound represented by the formula (2) include sodium halide (NaI, NaBr, NaCl, NaF, etc.), phosphorus halide (PBr ₃ , PCl ₃ , PCl ₅ , P ₂ Cl ₄ , PI ₃ , P _{3 2 I 4, PF 5, PF} 3 , _{etc.), AlF 3, AlBr 3,} AlI 3, AlCl 3, SiF 4, SiCl 4, SiCl 3, Si 2 Cl 6, SiBr 4, SiBrCl 3, SiBr 2 Cl 2, SiI ₄ , SF ₂ , SF ₄ , SF ₆ , S ₂ F ₁₀ , SCl ₂ , S ₂ Cl ₂ , S ₂ Br ₂ , GeF ₄ , GeCl ₄ , GeBr ₄ , GeI ₄ , GeF ₂ , GeCl ₂ , GeBr ₂ , GeI ₂ , AsF ₃ , AsCl ₃ , AsBr ₃ , AsI ₃ , AsF ₅ , SeF ₄ , SeF ₆ , SeCl ₂ , SeCl _{4, Se 2 Br 2, SeBr} 4, SnF 4, SnCl 4, SnBr 4, SnI 4, SnF 2, SnCl 2, SnBr 2, SnI 2, SbF 3, SbCl 3, SbBr 3, SbI 3, SbF 5, SbCl _{5, PbF 4, PbCl 4,} PbF 2, PbCl 2, PbBr 2, PbI 2, BiF 3, BiCl 3, BiBr 3, BiI 3, TeF 4, Te 2 F 10, TeF 6, TeCl 2, TeCl 4, TeBr ₂ , TeBr ₄ , TeI _{4 and the} like, preferably sodium halide (NaI, NaBr, NaCl, NaF, etc.), phosphorus halide (PBr ₃ , PCl ₃ , PCl ₅ , P ₂ Cl ₄ , PI ₃ , P ₂ I ₄ , PF ₅ , PF ₃ etc.), more preferably NaBr, NaCl , PBr ₃ , PCl ₃ .

In the formula (3), L is one or more elements selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium and radium, preferably sodium, potassium, rubidium, cesium , One or more elements selected from francium and beryllium, more preferably one or more selected from sodium and potassium, and still more preferably sodium.
y is 0.5 or more and 3 or less, preferably 0.7 or more and 2.5 or less, more preferably 1 or more and 2 or less, and further preferably 2.
In the formula (3), S means sulfur.

Specific examples of the compound represented by the formula (3) include Na ₂ S (sodium sulfide), K ₂ S, Rb ₂ S, BeS, MgS, CaS, SrS, BaS, and the like. You may mix and use above.

In addition to the above raw materials, the solid electrolyte raw material of the present invention may further use a compound (vitrification accelerator) that reduces the glass transition temperature.
Examples of the vitrification promoter include inorganic compounds such as Na ₃ PO ₄ , Na ₄ SiO ₄ , Na ₄ GeO ₄ , Na ₃ BO ₃ , Na ₃ AlO ₃ , Na ₃ CaO ₃ , and Na ₃ InO ₃ .

(2) Method for Producing Amorphous Solid Electrolyte Hereinafter, the raw material is a solid electrolyte using sodium sulfide, diphosphorus pentasulfide, which is a compound represented by formula (3), and a halogen compound, which is a compound represented by formula (2). A method for producing (glass) will be described.
The ratio (molar ratio) of sodium sulfide to diphosphorus pentasulfide is, for example, 60:40 to 90:10, preferably 65:35 to 85:15 or 70:30 to 90:10, and more preferably 67. : 33-83: 17 or 72: 28-88: 12, more preferably 67: 33-80: 20 or 74: 26-86: 14, particularly preferably 70: 30-80: 20 or 75. : 25-85: 15, most preferably 72: 28-78: 22, or 77: 23-83: 17.

The ratio (molar ratio) of the total of sodium sulfide and diphosphorus pentasulfide to the halogen compound is, for example, 50:50 to 99: 1, preferably 55:45 to 97: 3 or 70:30 to 98: 2. More preferably, it is 60: 40-96: 4 or 80: 10-98: 2, More preferably, it is 70: 30-96: 4 or 80: 20-98: 2, Especially preferably, it is 85:15 97: 3.
In addition, it is preferable to heat-process, after mixing sodium sulfide, diphosphorus pentasulfide, and a halogen compound by MM process etc.

  The compounding ratio of sodium sulfide, diphosphorus pentasulfide and a halogen compound is exemplified, but the compound represented by the formula (3) used in place of sodium sulfide for the above compounding ratio, even when not a combination of these materials, Instead of diphosphorus pentasulfide, phosphorus sulfide, sulfur and phosphorus, phosphorus sulfide and sulfur, or one selected from phosphorus sulfide, sulfur and phosphorus may be applied.

Using the raw materials, an amorphous solid electrolyte (solid electrolyte glass) can be produced by the following method.
Raw materials (for example, sodium sulfide, diphosphorus pentasulfide and halogen compounds) are mixed at the above-mentioned mixing ratio, and reacted in a melt quenching method, a mechanical milling method (hereinafter, “mechanical milling” is appropriately referred to as “MM”), and a solvent. A solid electrolyte (glass) can be produced by processing by a slurry method, a solid phase method, or the like.

(I) Melting and quenching method The melting and quenching method is a method of obtaining a solid electrolyte (glass) by mixing a predetermined amount of raw materials, reacting them at a predetermined temperature, and then rapidly cooling them.
For example, a mixture of pellets in a mortar is placed in a carbon-coated quartz tube and vacuum-sealed. After reacting at a predetermined reaction temperature, the solid electrolyte (glass) 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.
The reaction time is preferably 0.1 hour to 12 hours, more preferably 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.

(Ii) Mechanical milling method (MM method)
The MM method is a method of obtaining a solid electrolyte (glass) by mixing a predetermined amount of raw materials and applying mechanical energy.
A method for applying mechanical energy is not particularly limited, and various ball mills can be exemplified.
For example, a solid electrolyte (glass) can be obtained by mixing P ₂ S ₅ , Na ₂ S and a halogen compound in a predetermined amount in a mortar and reacting them for a predetermined time using, for example, various ball mills.
The MM method using the above raw materials can be reacted at room temperature. Therefore, there is an advantage that a solid electrolyte (glass) having a charged composition can be obtained without thermal decomposition of the raw material.
In addition, the MM method has an advantage that it can be made into fine powder simultaneously with the production of the solid electrolyte (glass).

Various types such as a rotating ball mill, a rolling ball mill, a vibrating ball mill, and a planetary ball mill can be used for the MM method.
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.
The balls of the ball mill may be used by mixing balls having different diameters.
Moreover, you may adjust the temperature in the mill in the case of MM processing.
It is preferable that the raw material temperature during the MM treatment be 60 ° C. or higher and 160 ° C. or lower.

(Iii) Solid phase method The solid phase method is a method for obtaining a solid electrolyte (glass) by mixing raw materials and heating at a predetermined temperature. For example, a solid electrolyte (glass) can be obtained by mixing P ₂ S ₅ , Na ₂ S and a halogen compound in a predetermined amount in a mortar and heating at a temperature of 100 to 900 ° C.

(Iv) Slurry method The slurry method is a method for producing a solid electrolyte glass by contacting a raw material in a solvent.
According to the slurry method, solid electrolyte glass can be produced without using special equipment such as a mechanical milling device. Therefore, a conductive material can be manufactured at a low cost. Moreover, since mechanical milling is not performed, it is possible to prevent generation of impurities due to peeling of the wall surface of the mechanical milling device.
Further, since no mechanical milling device is used, there is no drawback that glass adheres to the ball and the mill container.

The solvent is preferably an organic solvent, more preferably an aprotic solvent, and still more preferably a hydrocarbon organic solvent.
Examples of the aprotic solvent include aprotic organic solvents (for example, hydrocarbon-based organic solvents), aprotic polar organic compounds (for example, amide compounds, lactam compounds, urea compounds, organic sulfur compounds, and cyclic organic phosphorus compounds). Etc.), and any one of them can be used as a single solvent or a mixed solvent composed of two or more of these.

As the hydrocarbon solvent, saturated hydrocarbon, unsaturated hydrocarbon, or aromatic hydrocarbon can be used.
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.
As the hydrocarbon solvent, toluene and xylene are particularly preferable.

  The aprotic solvent and the hydrocarbon solvent are 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.

You may add another solvent to the solvent used as needed.
Specific examples of the other solvents include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; alcohols such as ethanol and butanol; esters such as ethyl acetate; dichloromethane, chlorobenzene, heptane fluoride, fluoride Examples thereof include halogenated hydrocarbons such as fluorinated compounds such as benzene 2,3-dihydroperfluoropentane, 1,1,2,2,3,3,4-heptafluorocyclopentane.

  The solvent used in the above-described slurry method can be used in the same manner as the solvent used in the production method described later.

  The amount of the solvent is preferably such that the raw material becomes a solution or slurry by the addition of the solvent. Usually, the addition amount of the raw material (total amount) with respect to 1 liter of solvent is about 0.001 kg to 1 kg. Preferably they are 0.005 Kg or more and 0.5 Kg or less, Especially preferably, they are 0.01 Kg or more and 0.3 Kg or less.

The method for contacting the raw materials in a solvent is not particularly limited. For example, there is a method of stirring a mixture of a raw material and a solvent in a container having a stirring device, and stirring is preferably performed at the time of contact.
The temperature during the contact (reaction) step is usually 50 ° C. or higher and 300 ° C. or lower, preferably 60 ° C. or higher and 250 ° C. or lower, more preferably 70 ° C. or higher and 200 ° C. or lower.
Moreover, the time at the time of a contact process is 5 minutes or more and 200 hours or less normally, Preferably they are 10 minutes or more and 100 hours or less. If the time during the contacting step is less than 5 minutes, the reaction may be insufficient. If the contact time is too short, the raw material may remain.
Note that the temperature and time may be combined using several conditions as steps. For example, contact may be performed at 100 ° C. for 1 hour from the start of contact, and heated at 150 ° C. for 10 hours after 1 hour.

  The contacting step is preferably carried out in an inert gas atmosphere such as nitrogen or argon. The dew point of the inert gas is preferably −20 ° C. or less, particularly preferably −40 ° C. or less. The pressure is usually normal pressure to 100 MPa, preferably normal pressure to 20 MPa.

  After the contact treatment, the generated solid portion and the solvent are separated to recover the solid electrolyte glass. Separation can be performed by a known method such as decantation, filtration, drying, or a combination thereof.

(V) Wet mechanical milling method (wet MM method)
The wet mechanical milling method is a method in which a raw material is manufactured by mechanical milling in a solvent.
In the wet mechanical milling method, the mechanical milling process is performed in a state where a solvent is added, thereby suppressing the effect of increasing the grain size during the process and efficiently promoting the synthesis reaction. Thereby, it is possible to obtain an ion conductive material having excellent uniformity and a low content of unreacted raw materials. Further, it is possible to prevent the raw materials and reactants from sticking to the vessel wall and the like, and to improve the product yield.

  The amount of the solvent is preferably such that the raw material becomes a solution or slurry by the addition of the solvent. Usually, the amount of the raw material (total amount) added to 1 liter of solvent is about 0.01 kg to 1 kg. Preferably they are 0.1 kg or more and 1 kg or less, Most preferably, they are 0.2 kg or more and 0.8 kg or less.

  Various types of grinding methods can be used for the mechanical milling treatment. In particular, it is preferable to use a planetary ball mill. The planetary ball mill can efficiently generate very high impact energy by rotating the platform while the pot rotates. Also preferred is a bead mill.

The rotation speed and rotation time of the mechanical milling treatment are not particularly limited, but the higher the rotation speed, the higher the glassy electrolyte generation rate, and the longer the rotation time, the higher the conversion rate of the raw material into the glassy electrolyte. However, if the rotational speed of the mechanical milling process is increased, the burden on the pulverizer may be increased. If the rotation time is increased, it takes time to produce the glassy electrolyte.
For example, when a planetary ball mill is used, the rotational speed may be 250 rpm / min to 300 rpm / min, and the treatment may be 5 minutes to 50 hours. More preferably, it is 10 minutes or more and 40 hours or less.

Since mechanical milling is performed in the presence of a solvent, the processing time can be shortened. You may heat from room temperature to 200 degreeC as needed.
An amorphous solid electrolyte is obtained by drying the resulting product after the mechanical milling treatment and removing the solvent.

(Vi) Improved slurry method The improved slurry method comprises a mechanical energy supply means for imparting mechanical energy to a raw material in a solvent, a contact means for contacting the raw material in a solvent, a mechanical energy supply means and a contact means. A solid electrolyte is produced using a production apparatus comprising a coupling means for coupling the raw materials and / or a circulation means for circulating the raw material and / or a reactant of the raw material between the mechanical energy supply means and the contact means through the coupling means. Is the method. A solid electrolyte glass is obtained by drying the reaction product and removing the solvent.
The said raw material and solvent can use the same thing as the raw material and solvent of a wet mechanical milling method.

  In the improved slurry method, the reaction is performed with the solvent added to the raw material. By making it react in the state which added the solvent, the granulation effect at the time of a process can be suppressed and a synthesis reaction can be accelerated | stimulated efficiently. Thereby, the solid electrolyte glass which is excellent in uniformity and has a low content of unreacted raw materials can be obtained. Further, it is possible to prevent the raw materials and reactants from sticking to the vessel wall and the like, and to improve the product yield.

FIG. 4 is a diagram showing an example of a production apparatus that can be used in the improved slurry method.
The manufacturing apparatus 1 includes a pulverizer (crushing and synthesizing means) 10 that synthesizes a solid electrolyte by reacting while pulverizing raw materials, and a reaction tank (synthesizing means) 20 that synthesizes the solid electrolyte by reacting the raw materials. The reaction tank 20 includes a container 22 and a stirring blade 24, and the stirring blade 24 is driven by a motor (M).

  When manufacturing a solid electrolyte using this apparatus 1, a solvent and a raw material are supplied to the grinder 10 and the reaction tank 20, respectively. Hot water (HW) enters and exits the heater 30 (RHW). While maintaining the temperature in the pulverizer 10 with the heater 30, the raw materials are reacted while being pulverized in a solvent to synthesize a solid electrolyte. While maintaining the temperature in the reaction vessel 20 by the oil bath 40, the raw materials are reacted in a solvent to synthesize a solid electrolyte. The temperature in the reaction vessel 20 is measured with a thermometer (Th). At this time, the stirring blade 24 is rotated by the motor (M) to stir the reaction system so that the slurry composed of the raw material and the solvent does not precipitate. Cooling water (CW) enters and exits the cooling pipe 26 (RCW). The cooling pipe 26 cools and liquefies the vaporized solvent in the container 22 and returns it to the container 22. While the solid electrolyte is synthesized in the pulverizer 10 and the reaction tank 20, the raw material being reacted is circulated between the pulverizer 10 and the reaction tank 20 through the connecting pipes 50 and 52 by the pump 54. The temperature of the raw material and the solvent fed into the pulverizer 10 is measured by a thermometer (Th) provided in the second connecting pipe before the pulverizer 10.

  The pulverizer 10 is provided with a heater 30 (first temperature stabilizing means) through which warm water can be passed around the pulverizer 10 in order to keep the temperature inside the pulverizer 10. The reaction tank 20 is in an oil bath 40 (second temperature stabilizing means) in order to maintain the temperature in the reaction tank 20. The oil bath 40 heats the raw material and solvent in the container 22 to a predetermined temperature. The reaction tank 20 is provided with a cooling pipe 26 that cools and vaporizes the evaporated solvent.

  The pulverizer 10 and the reaction tank 20 are connected by a first connecting pipe 50 and a second connecting pipe 52 (connecting means). The first connecting pipe 50 moves the raw material and solvent in the pulverizer 10 to the reaction tank 20, and the second connecting part 52 moves the raw material and solvent in the reaction tank 20 into the pulverizer 10. A pump 54 (for example, a diaphragm pump) (circulation means) is provided in the second connection pipe 52 in order to circulate the raw materials and the like through the connection pipes 50 and 52.

FIG. 5 is a view showing another example of a manufacturing apparatus that can be used in the slurry method.
The manufacturing apparatus 2 is the same as the manufacturing apparatus 1 described above except that a heat exchanger 60 (heat exchange means) is provided in the second connecting portion 52. The same members as those of the manufacturing apparatus 1 are denoted by the same reference numerals and description thereof is omitted.
The heat exchanger 60 cools the high-temperature raw material and solvent sent out from the reaction tank 20 and sends them to the stirrer 10. For example, when the reaction is performed at a temperature exceeding 80 ° C. in the reaction tank 20, the temperature of the raw material or the like is cooled to 80 ° C. or less and sent to the stirrer 10.

  The pulverizer 10 may be any pulverizer as long as the solid electrolyte can be produced by reacting the raw materials while being pulverized and mixed. For example, a rotary mill (rolling mill), a rocking mill, a vibration mill, and a bead mill can be used. A bead mill is preferable in that the raw material can be finely pulverized. The finer the raw material, the higher the reactivity, and the solid electrolyte glass can be produced in a short time.

When the pulverizer includes balls, the balls are preferably made of zirconium, reinforced alumina, or alumina in order to prevent foreign matter from being mixed into the solid electrolyte glass due to wear of the balls and the container.
Moreover, in order to prevent mixing of the balls from the pulverizer 10 to the reaction tank 20, a filter for separating the balls, the raw material, and the solvent may be provided in the pulverizer 10 or the first connecting pipe 50 as necessary.

  The pulverization temperature in the pulverizer is, for example, 20 ° C. or higher and 80 ° C. or lower, and preferably 20 ° C. or higher and 60 ° C. or lower. When the processing temperature in a pulverizer is less than 20 ° C., the effect of shortening the reaction time required for production may be reduced. On the other hand, when the processing temperature in the pulverizer is higher than 80 ° C., the strength of the container and ball material zirconia, reinforced alumina, and alumina is significantly reduced, so that the container and ball are worn and deteriorated. There is a risk of contamination.

  The reaction tank 20 may be any reaction tank as long as it can react the raw materials to produce the solid electrolyte glass. Usually, the reaction tank has a container, mixing means such as a stirrer, and cooling means. The mixing means mixes the slurry composed of the raw material and the solvent in the container so that the slurry does not precipitate. The cooling means cools the evaporated solvent and returns it to the container.

The container 22 is preferably made of metal or glass. When reacting at a reaction temperature equal to or higher than the boiling point of the solvent, it is preferable to use a pressure resistant container.
The reaction temperature in the container 22 is, for example, 60 ° C. or higher and 300 ° C. or lower, and preferably 80 ° C. or higher and 200 ° C. or lower. When the reaction temperature in a container is less than 60 degreeC, there exists a possibility that vitrification reaction may take time and production efficiency may not be enough. On the other hand, when the reaction temperature in the container exceeds 300 ° C., undesirable crystals may be precipitated.

The reaction is preferably carried out at a high temperature because the region where the temperature is high is fast. However, if the temperature of the pulverizer exceeds 80 ° C., mechanical problems such as wear may occur. Accordingly, the reaction tank is preferably set at a high reaction temperature and the pulverizer is kept at a relatively low temperature.
The ratio between the capacity of the reaction tank 20 and the capacity of the pulverizer 10 may be arbitrary, but the capacity of the reaction tank 20 is usually about 1 to 100 times the capacity of the pulverizer 10.

  The amount of the hydrocarbon-based solvent is preferably such that the raw material becomes a solution or slurry by the addition of the solvent. Usually, the amount of raw material (total amount) added to 1 kg of solvent is about 0.03 kg to 1 kg. The amount is preferably 0.05 kg or more, more preferably 0.5 kg or less, particularly preferably 0.1 kg or more and 0.3 kg or less.

(Vii) Alternate implementation of the mechanical milling method and the contact method The alternate implementation of the mechanical milling method and the contact method includes a step of mechanically milling the raw material and a contact step of contacting the raw material in a solvent, and the mechanical milling treatment step And the contact step is repeated alternately.

In the mechanical milling process, various types of pulverization methods exemplified by the MM method can be used. The temperature of the mechanical milling process is the same as the temperature of the mechanical energy supply means (pulverizer 10) of the improved slurry method.
The rotation speed and rotation time of the mechanical milling treatment are not particularly limited, but the higher the rotation speed, the higher the glassy electrolyte generation rate, and the longer the rotation time, the higher the conversion rate of the raw material into the glassy electrolyte. For example, when a planetary ball mill is used, the rotational speed may be 250 rpm / min to 300 rpm / min, and the treatment may be 5 minutes to 50 hours.
The treatment time indicates the time that the raw material and the glassy electrolyte remain in the planetary ball mill. Accordingly, the raw material and the glassy electrolyte circulate in the planetary ball mill and the reaction vessel, but the total time that the raw material and the glassy electrolyte stay in the planetary ball mill from the start to the end of the reaction.
If the above time is short, unreacted raw materials may remain, and if the above time is long, the capacity of the pulverizer is increased, and the amount of raw materials and glassy electrolyte that can be stored at one time is increased, or until the following reaction is completed. There is a possibility that the problem of long time may occur.

About a contact process, the contact means illustrated by the improved slurry method can be used. Moreover, the temperature of a contact process is the same as the reaction temperature in the contact means (container 22) of an improved slurry method.
The time for the contacting step is preferably from 5 minutes to 200 hours.
Here, the time of the said contact process shows the time when the raw material and the glassy electrolyte remain in the reaction tank. Accordingly, the raw material and the glassy electrolyte circulate through the planetary ball mill and the reaction tank, but the total time that the raw material and the glassy electrolyte remain in the reaction tank from the start to the end of the reaction.

  The mechanical milling process and the contact process described above are repeated alternately. The number of repetitions is preferably 2 or more and 100 or less. More preferably, the number of repetitions is 5 or more and 100 or less, and further preferably 10 or more and 100 or less.

As mentioned above, although the manufacturing method of solid electrolyte glass was demonstrated, even if it is a case of any of the above-mentioned manufacturing methods, the order (mixing order) which mixes a raw material is not specifically limited, The composition of final solid electrolyte glass is It suffices if it is in a range satisfying the above formula (1).
For example, when the raw materials are Na ₂ S, P ₂ S ₅ and NaBr, if the mechanical milling method is used, the raw materials Na ₂ S, P ₂ S ₅ and NaBr may be mixed and then milled; Na After milling ₂ S and P ₂ S ₅ , NaBr may be added and further milled; after NaBr and P ₂ S ₅ are milled, Na ₂ S may be added and further milled; Na ₂ S and NaBr After milling, P ₂ S ₅ may be added for further milling. Further, a milling treatment may be performed after mixing a mixture obtained by mixing and milling Na ₂ S and NaBr and a mixture obtained by mixing and milling NaBr and P ₂ S ₅ .
In addition to the above, when two or more mixing processes are performed, two or more different methods may be combined.
In the case of the solid phase method, Na ₂ S and P ₂ S ₅ may be processed by mechanical milling, mixed with NaBr, and then processed by the solid phase method. Na ₂ S and LiBr may be processed by the solid phase method. A solid electrolyte (glass) may be produced by mixing the obtained one and P ₂ S ₅ and NaBr that have been subjected to a melt quenching treatment and performing a slurry method.

(3) Manufacturing method of crystallized solid electrolyte A crystallized solid electrolyte (solid electrolyte glass ceramic) is obtained by heat-treating the amorphous solid electrolyte (solid electrolyte glass). Heating is preferably performed in an environment with a dew point of −40 ° C. or lower, more preferably in an environment with a dew point of −60 ° C. or lower.
The pressure at the time of heating may be a normal pressure or a reduced pressure.
The atmosphere may be in the air or an inert atmosphere.
Furthermore, you may heat in a solvent.

The heating temperature is preferably not less than the glass transition temperature (Tg) of the solid electrolyte glass and not more than the crystallization temperature (Tc) of the solid electrolyte glass + 100 ° C. or less. When the heating temperature is less than Tg of the solid electrolyte glass, the production time may be very long. On the other hand, when it exceeds (Tc + 100 ° C.), impurities or the like may be contained in the obtained solid electrolyte glass ceramic, and the ionic conductivity may be lowered.
The heating temperature is more preferably (Tg + 5 ° C.) or more and (Tc + 90 ° C.) or less, and further preferably (Tg + 10 ° C.) or more and (Tc + 80 ° C.) or less.
For example, the heating temperature is 150 ° C. or higher and 360 ° C. or lower, preferably 160 ° C. or higher and 350 ° C. or lower, more preferably 180 ° C. or higher and 310 ° C. or lower, more preferably 180 ° C. or higher and 290 ° C. or lower, Especially preferably, it is 190 degreeC or more and 270 degrees C or less. Further, when there are two temperature peaks in the thermophysical property, the peak temperature on the low temperature side is defined as Tc in this case, and heat treatment is performed between Tc on the low temperature side and the second crystallization peak on the high temperature side (Tc2). preferable.
There is no specific specification for the temperature raising method. The temperature may be raised slowly to a predetermined temperature or heated rapidly.

The crystallization temperature of the solid electrolyte glass is measured by heating about 20 mg of the solid electrolyte glass at a heating rate of 10 ° C./min using, for example, a thermogravimetric measuring device (TGA / DSC1 manufactured by METTLER TOLEDO). It can be specified. The crystallization temperature and the like may change depending on the temperature rising rate and the like, and it is necessary to select it based on Tc measured at a rate close to the temperature rising rate for heat treatment.

The heating time is preferably 0.005 minutes or more and 10 hours or less. More preferably, it is 0.005 minutes or more and 5 hours or less, and particularly preferably 0.01 minutes or more and 3 hours or less.
If the heating time is less than 0.005 minutes, the solid electrolyte glass ceramic contains a large amount of solid electrolyte glass, and the ionic conductivity may be lowered. On the other hand, if the heating time exceeds 10 hours, impurities or the like may be generated in the solid electrolyte glass ceramic, and the ionic conductivity may be lowered.

[Second Manufacturing Method of Solid Electrolyte]
The solid electrolyte of the present invention can be produced not only by the first production method of the solid electrolyte but also by the following second production method.
The second production method is a method in which a halogen compound is further added to the solid electrolyte glass obtained in the course of the first production method, followed by crystallization by heating at a predetermined temperature and for a predetermined time.
The solid electrolyte glass and the halogen compound are preferably mixed by MM treatment or the like. The materials that can be used, the method for producing the solid electrolyte glass, the heating time and the heating temperature of the mixed material obtained by adding the halogen compound to the solid electrolyte glass are the same as in the crystallization of the first production method.

  In the second production method, the amount of the halogen compound used as the raw material for the solid electrolyte glass and the total amount of the halogen compound added to the solid electrolyte glass are used as the raw material for the solid electrolyte glass in the first production method. This is the same as the amount of the halogen compound. The ratio of the halogen compound which is a raw material of the solid electrolyte (glass) and the halogen compound added to the solid electrolyte glass is not particularly limited.

[Third Manufacturing Method of Solid Electrolyte]
The solid electrolyte (solid electrolyte glass ceramic) of the present invention can be produced not only by the first and second production methods of the solid electrolyte but also by the following third production method.
In the third production method, a solid electrolyte glass containing no halogen element is produced without using a halogen compound, and the solid electrolyte glass not containing the halogen element and the halogen compound are heat-treated at a predetermined temperature for a predetermined time for crystallization. Thus, a solid electrolyte (solid electrolyte glass ceramic) is manufactured.
The materials that can be used, the production method of the solid electrolyte glass, the crystallization conditions, and the like are the same as those in the first production method.

The solid electrolyte glass used in the third production method is preferably a solid electrolyte glass represented by the following formula (1 ′).
L _a P _c S _d (1 ′)
(L, P, S, a, c, and d are the same as in equation (1).)

  As the compound represented by the formula (1 ′), the compound represented by the formula (3) and any one selected from phosphorus sulfide, sulfur and phosphorus, phosphorus sulfide and sulfur, and phosphorus sulfide, sulfur and phosphorus are used. Can be manufactured.

  When using sodium sulfide and phosphorous pentasulfide as the raw material for the solid electrolyte glass containing no halogen element used in the third production method, the ratio (molar ratio) of sodium sulfide to phosphorous pentasulfide is, for example, 60:40 to 90 : 10, preferably 65:35 to 85:15 or 70:30 to 90:10, more preferably 67:33 to 83:17 or 72:28 to 88:12, and even more preferably 67 : 33-80: 20 or 74: 26-86: 14, particularly preferably 70: 30-80: 20 or 75: 25-85: 15, most preferably 72: 28-78: 22, or 77: 23-83: 17.

The use ratio (molar ratio) of the solid electrolyte glass and the halogen compound is, for example, 50:50 to 99: 1, preferably 55:45 to 97: 3 or 70:30 to 98: 2, and more preferably 60. : 40 to 96: 4 or 80:10 to 98: 2, more preferably 70:30 to 96: 4 or 80:20 to 98: 2, most preferably 85:15 to 97: 3. is there.
In addition, it is preferable to heat-process, after mixing the solid electrolyte glass and halogen compound used with a 3rd manufacturing method by MM process.

[Battery materials]
Since the solid electrolyte of the present invention is hardly hydrolyzed and has high ionic conductivity, it can be particularly suitably used as a solid electrolyte layer of an all-solid battery.
The solid electrolyte of the present invention may be used as a solid electrolyte composition by mixing with a binder (binder), a positive electrode active material, a negative electrode active material, a conductive additive, the halogen compound, an organic solvent, and the like.
The solid electrolyte composition can be used as a constituent material of a battery, such as a positive electrode, an electrolyte layer, and a negative electrode, and a material for forming a member (layer) constituting the battery.

Examples of binders include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-containing resins such as fluorine rubber; thermoplastic resins such as polypropylene and polyethylene; ethylene-propylene-diene rubber (EPDM), sulfonated EPDM, natural Butyl rubber (NBR) or the like can be used alone or as a mixture of two or more.
In addition, an aqueous binder such as a cellulose binder or an aqueous dispersion of styrene butadiene rubber (SBR) can also be used.

The positive electrode active material is not particularly limited as long as it is a compound capable of doping and dedoping sodium ions, and is preferably a positive electrode active material that is an inorganic compound.
In the sulfide-based positive electrode active material, sulfur (S), titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), iron sulfide (FeS, FeS ₂ ), copper sulfide (CuS), and nickel sulfide (Ni ₃ S ₂ ) Etc., and TiS ₂ is preferable.
Examples of the oxide-based positive electrode active material include bismuth oxide (Bi ₂ O ₃ ), bismuth leadate (Bi ₂ Pb ₂ O ₅ ), copper oxide (CuO), and vanadium oxide (V ₆ O ₁₃ ).
In the positive electrode active material which is a sodium inorganic compound, an oxide represented by NaM1 _a O ₂ such as NaFeO ₂ , NaMnO ₂ , NaNiO ₂ , NaCoO ₂ ; represented by Na _0.44 Mn _1-a M1 _a O ₂ Oxide; oxide represented by Na _0.7 Mn _1-a M1 _a O _2.05 (M1 is one or more transition metal elements, 0 ≦ a <1), Na ₆ Fe ₂ Si ₁₂ O ₃₀ , _{Na 2 Fe 5 Si 12 O 30} Na b M2 c Si 12 O 30 with oxide represented such (M2 is one or more transition metal elements, 2 ≦ b ≦ 6,2 ≦ c ≦ 5); Na 2 _{Fe 2 Si 6 O 18, Na} 2 MnFeSi 6 O 18 oxide represented by NadM3 _e Si ₆ O _18, such as (M3 is one or more transition metal elements, 3 ≦ d ≦ 6,1 ≦ e ≦ 2) , _Na 2 FeSiO ₆ etc. Na _f 4 _g Si oxide represented by ₂ O ₆ (M4 is a transition metal element, one or more elements selected from the group consisting of Mg and Al, 1 ≦ f ≦ 2,1 ≦ g ≦ 2), NaFePO 4, Phosphate salts such as Na ₃ Fe ₂ (PO ₄ ) ₃ ; Borate salts such as NaFeBO ₄ and Na ₃ Fe ₂ (BO ₄ ) ₃ ; Tables represented by Na _h M5F ₆ such as Na ₃ FeF ₆ and Na ₂ MnF ₆ Fluoride (M5 is one or more transition metal elements, 2 ≦ h ≦ 3) and the like.

Examples of the shape of the positive electrode active material include a particle shape, preferably a true spherical shape or an elliptical spherical shape.
When the positive electrode active material is in the form of particles, the average particle size is preferably in the range of 0.1 to 100 μm, more preferably in the range of 1 to 50 μm, and particularly preferably in the range of 1 to 25 μm. is there. When the average particle diameter of the positive electrode active material particles deviates from the above range, a dense positive electrode active material layer may not be obtained.

The negative electrode active material is not particularly limited as long as it is a substance that can be doped and dedoped with sodium ions, and sodium metal, a sodium alloy, a carbon material, and the like can be used.
Examples of the sodium alloy include Na—Sn, Na—Zn, and Na—Al.
Carbon materials include artificial graphite, graphite carbon fiber, resin-fired carbon, pyrolytic vapor-grown carbon, coke, mesocarbon microbeads (MCMB), furfuryl alcohol resin-fired carbon, polyacene, pitch-based carbon fiber, vapor-phase growth Examples include carbon fiber, natural graphite, and non-graphitizable carbon. Or it may be a mixture thereof. The carbon material is preferably artificial graphite.

The conductive auxiliary agent only needs to have conductivity, and the conductivity of the conductive auxiliary agent is preferably 1 × 10 ³ S / cm or more, more preferably 1 × 10 ⁵ S / cm or more. .
Examples of the conductive assistant include substances selected from carbon materials, metal powders and metal compounds, and mixtures thereof.
Specific examples of conductive aids are preferably carbon, nickel, copper, aluminum, indium, silver, cobalt, magnesium, lithium, chromium, gold, ruthenium, platinum, beryllium, iridium, molybdenum, niobium, osnium, rhodium, tungsten And a substance containing at least one element selected from the group consisting of zinc, more preferably simple carbon, carbon, nickel, copper, silver, cobalt, magnesium, lithium, ruthenium, gold, platinum, niobium, osnium or rhodium A simple metal, a mixture or a compound containing
In particular, specific examples of the carbon material for the conductive assistant include carbon black such as ketjen black, acetylene black, denka black, thermal black, and channel black, graphite, carbon fiber, activated carbon, and the like. These can be used alone or in combination of two or more.
Among the above conductive assistants, acetylene black, denka black, and ketjen black having high electron conductivity are preferable.

[All-solid battery]
The all solid state battery of the present invention can be manufactured by using the solid electrolyte composition.
In the battery of the present invention, at least one of the positive electrode layer, the electrolyte layer, and the negative electrode layer includes the solid electrolyte of the present invention. Each layer can be manufactured by a known method.
In addition, when manufacturing a positive electrode layer, a negative electrode layer, or an electrolyte layer using the above-described solid electrolyte glass (electrolyte precursor), the layer is formed using the electrolyte precursor, and then heated under the predetermined heating condition. The battery of the present invention can also be manufactured.

Another battery of the present invention is a battery in which at least one of a positive electrode layer, an electrolyte layer, and a negative electrode layer is manufactured using at least one of the solid electrolyte and the electrolyte composition of the present invention.
It suffices that at least one of the positive electrode layer, the electrolyte layer, and the negative electrode layer is manufactured using the solid electrolyte or electrolyte composition of the present invention, and the others are the same as those of the battery of the present invention.
Hereinafter, each layer of the battery of the present invention will be described.

[Solid electrolyte layer (solid electrolyte sheet)]
The electrolyte layer (solid electrolyte sheet) of the present invention includes at least one of the solid electrolyte and the solid electrolyte composition of the present invention. In addition to the solid electrolyte of the present invention, it may contain the above-described binder or the like according to the purpose of use, and includes other electrolytes (polymer-based solid electrolyte, oxide-based solid electrolyte, electrolyte precursor). Also good.

The solid electrolyte of the solid electrolyte layer is preferably fused. Here, the fusion means that a part of the solid electrolyte particles is dissolved, and the dissolved part is integrated with other solid electrolyte particles.
The solid electrolyte layer may be a solid electrolyte plate. In addition, the case where part or all of the solid electrolyte particles are dissolved to form a plate-like body is included.
The thickness of the solid electrolyte layer may be appropriately selected depending on the type of the all-solid battery intended, but is usually preferably in the range of 1 μm to 500 μm. More preferably, it is 10-300 micrometers, Most preferably, it is 20-150 micrometers.

  A solid electrolyte layer can be manufactured by apply | coating the slurry containing the solid electrolyte of this invention, a binder, and a solvent, for example. Moreover, you may manufacture by an electrostatic screen printing method using a granular solid electrolyte.

[Positive electrode layer]
The content of the positive electrode active material in the positive electrode layer containing the solid electrolyte and the positive electrode active material of the present invention is preferably in the range of 50 to 90% by weight, more preferably in the range of 60 to 80% by weight. .
The solid electrolyte used for the positive electrode layer can be a solid electrolyte glass ceramic, a solid electrolyte glass, or a mixture thereof. When a battery is formed by pressurization and heating, the solid electrolyte glass is better. Further, the positive electrode layer may contain the above-mentioned conductive auxiliary agent and binder.

  The thickness of the positive electrode layer may be appropriately selected depending on the kind of the all-solid battery intended, but it is usually preferably in the range of 1 μm to 500 μm. More preferably, it is 10-300 micrometers, Most preferably, it is 20-150 micrometers.

  A positive electrode layer can be manufactured by a well-known method, for example, can be manufactured by the apply | coating method and an electrostatic method (an electrostatic spray method, an electrostatic screen method, etc.).

[Negative electrode layer]
The content of the negative electrode active material in the negative electrode layer containing the solid electrolyte and the negative electrode active material of the present invention is preferably in the range of 50 to 90% by weight, and more preferably in the range of 60 to 80% by weight. .
The solid electrolyte used for the negative electrode layer can be a solid electrolyte glass ceramic, a solid electrolyte glass, or a mixture thereof. When a battery is formed by pressurization and heating, the solid electrolyte glass is better. Moreover, the negative electrode layer may contain the said conductive support agent and a binder.
The thickness and manufacturing method of the negative electrode layer are the same as those of the positive electrode layer.

[Current collector]
The battery of the present invention preferably uses a current collector in addition to the positive electrode layer, the electrolyte layer, and the negative electrode layer. A known current collector can be used. For example, a layer coated with Au or the like that reacts with a sulfide-based solid electrolyte such as Au, Pt, Al, Ti, or Cu can be used.

Comparative Example 1
0.650 g (0.00833 mol) of sodium sulfide (manufactured by High Purity Chemical Laboratory) and 0.618 g (0.00278 mol) of diphosphorus pentasulfide (manufactured by Aldrich) were mixed well. Then, the mixed powder, 10 zirconia balls having a diameter of 10 mm, and a planetary ball mill (manufactured by Fritsch Co., Ltd .: Model No. P-7) are put into an alumina pot and completely sealed, and the alumina pot is filled with nitrogen, The atmosphere was nitrogen.
For the first few minutes, the planetary ball mill was rotated at a low speed (85 rpm) to sufficiently mix sodium sulfide and diphosphorus pentasulfide. Thereafter, the rotational speed of the planetary ball mill was gradually increased to 370 rpm. Mechanical milling was performed for 20 hours at a rotational speed of the planetary ball mill at 370 rpm.
As a result of evaluating the mechanically milled white-yellow powder by X-ray measurement, it can be confirmed that it is vitrified, and an amorphous solid electrolyte (sulfide-based glass: Na ₂ S / P ₂ S ₅ = 75). / 25, MM method) was obtained. The ionic conductivity of this solid electrolyte precursor was 1.0 × 10 ⁻⁵ S / cm.

The ionic conductivity was evaluated by the following method.
A sample was formed into a shape with a cross section of 10 mmφ (cross section S = 0.785 cm ² ) and a height (L) of 0.1 to 0.3 cm, electrode terminals were taken from the top and bottom of the sample piece, and measured by the AC impedance method (Frequency range: 5 MHz to 0.5 Hz, amplitude: 10 mV), Cole-Cole plot was obtained. In the vicinity of the right end of the arc observed in the high-frequency region, the real part Z ′ (Ω) at the point where −Z ″ (Ω) is minimized is defined as the bulk resistance R (Ω) of the electrolyte. The conductivity σ (S / cm) was calculated.
R = ρ (L / S)
σ = 1 / ρ
In this example, the distance between the leads was measured as about 60 cm.

Comparative Example 2
The solid electrolyte precursor obtained in Comparative Example 1 was crystallized by heat treatment at 280 ° C. for 2 hours to obtain a solid electrolyte. The ionic conductivity of the solid electrolyte after the heat treatment was 2.0 × 10 ⁻⁴ S / cm. As a result of X-ray diffraction measurement, it was confirmed that the structure was a cubic Na ₃ PS ₄ structure, and the obtained solid electrolyte was confirmed to be a solid electrolyte glass ceramic.

Example 1
An amorphous solid electrolyte (sulfurized) was prepared in the same manner as in Comparative Example 1 except that 0.843 g of the solid electrolyte precursor obtained in Comparative Example 1 and 0.156 g of sodium iodide (Aldrich) were used as raw materials. Physical glass: Na ₂ S / P ₂ S ₅ / NaI = 63/21/16, MM method) was produced. The ionic conductivity σ of this amorphous solid electrolyte at room temperature was 2.5 × 10 ⁻⁵ S / cm.
The obtained amorphous solid electrolyte was crystallized by heat treatment at 200 ° C. for 2 hours to obtain a solid electrolyte. The ionic conductivity of the solid electrolyte after the heat treatment was 8.0 × 10 ⁻⁴ S / cm.

Example 2
As raw materials, 0.507 g (0.0065 mol) of sodium sulfide, 0.482 g (0.00217 mol) of diphosphorus pentasulfide (Aldrich) and 0.221 g (0.00165 mol) of sodium iodide (Aldrich) are used. In the same manner as in Example 1, an amorphous solid electrolyte (sulfide-based glass: Na ₂ S / P ₂ S ₅ / NaI = 63/21/16, MM method) was produced. The ionic conductivity σ of this amorphous solid electrolyte at room temperature was 2.7 × 10 ⁻⁵ S / cm. The obtained amorphous solid electrolyte was crystallized by heat treatment at 200 ° C. for 2 hours. An electrolyte was obtained. The ionic conductivity of the solid electrolyte after the heat treatment was 7.5 × 10 ⁻⁴ S / cm.

Example 3
As raw materials, 0.566 g (0.00725 mol) of sodium sulfide (manufactured by High Purity Chemical Laboratory), 0.532 g (0.00239 mol) of diphosphorus pentasulfide (manufactured by Aldrich), sodium bromide (manufactured by Aldrich) 0 140 g (0.00161 mol) was mixed well. Then, the mixed powder, 10 zirconia balls having a diameter of 10 mm, and a planetary ball mill (manufactured by Fritsch: Model No. P-7) are put into an alumina pot and completely sealed, and the alumina pot is filled with argon, Argon atmosphere.
For the first few minutes, the planetary ball mill was rotated at a low speed (100 rpm) to sufficiently mix sodium sulfide and diphosphorus pentasulfide. Thereafter, the rotational speed of the planetary ball mill was gradually increased to 370 rpm. The planetary ball mill was mechanically milled at 370 rpm for 20 hours, and the electrolyte precursor (sulfide-based glass: Na ₂ S / P ₂ S ₅ / NaBr = 64/21/14, MM, white-yellow powder) Law). The ionic conductivity σ at room temperature of this electrolyte precursor was 2.8 × 10 ⁻⁵ S / cm.
The obtained amorphous solid electrolyte was crystallized by heat treatment at 200 ° C. for 2 hours to obtain a solid electrolyte. The ionic conductivity of the solid electrolyte after the heat treatment was 1.0 × 10 ⁻³ S / cm.

Example 4
As raw materials, sodium sulfide (manufactured by High-Purity Chemical Laboratory) 0.512 g (0.00657 mol), diphosphorus pentasulfide (manufactured by Aldrich) 0.482 g (0.00217 mol), sodium bromide (manufactured by Aldrich) 0 Amorphous solid electrolyte (sulfide-based glass: Na ₂ S / P ₂ S ₅ / NaBr = 58/19/23, MM method, except that .220 g (0.00253 mol) was used ) Was manufactured. The ionic conductivity σ at room temperature of this amorphous solid electrolyte was 3.0 × 10 ⁻⁵ S / cm.
The obtained amorphous solid electrolyte was crystallized by heat treatment at 200 ° C. for 2 hours to obtain a solid electrolyte. The ionic conductivity of the solid electrolyte after the heat treatment was 1.3 × 10 ⁻³ S / cm.

Example 5
As raw materials, sodium sulfide (manufactured by High-Purity Chemical Laboratory) 0.459 g (0.00588 mol), diphosphorus pentasulfide (manufactured by Aldrich) 0.431 g (0.00194 mol), sodium bromide (manufactured by Aldrich) 0 Solid electrolyte precursor (sulfide glass: Na ₂ S / P ₂ S ₅ / NaBr = 52/17/31, MM method) except that .302 g (0.00348 mol) was used Manufactured. This amorphous solid electrolyte had an ionic conductivity σ at room temperature of 3.1 × 10 ⁻⁵ S / cm.
The obtained amorphous solid electrolyte was heat-treated at 200 ° C. for 2 hours to obtain a crystallized solid electrolyte. The ionic conductivity of the solid electrolyte after the heat treatment was 1.2 × 10 ⁻³ S / cm.

Example 6
As raw materials, 0.63 g (0.00773 mol) of sodium sulfide (manufactured by High Purity Chemical Laboratory), 0.574 g (0.00258 mol) of diphosphorus pentasulfide (manufactured by Aldrich), sodium chloride (manufactured by Aldrich) Amorphous solid electrolyte (sulfide-based glass: Na ₂ S / P ₂ S ₅ / NaCl = 64/21/14, MM method) in the same manner as in Example 3 except that 072 g (0.00175 mol) was used. Manufactured. The ionic conductivity σ of this amorphous solid electrolyte at room temperature was 1.5 × 10 ⁻⁵ S / cm.
The obtained amorphous solid electrolyte was crystallized by heat treatment at 200 ° C. for 2 hours to obtain a solid electrolyte. The ionic conductivity of the solid electrolyte after the heat treatment was 0.6 × 10 ⁻³ S / cm.

Example 7
0.658 g (0.00844 mol) of sodium sulfide (manufactured by High Purity Chemical Research Laboratory) and 0.471 g (0.00212 mol) of diphosphorus pentasulfide (manufactured by Aldrich) under an argon atmosphere {Li ₂ S / P ₂ S ₅ = 80/20 (mol / mol)}, and 0.160 g (0.00058 mol) of phosphorus tribromide was further added dropwise and mixed well. The mixed powder, 10 alumina balls having a diameter of 10 mm, and a planetary ball mill (manufactured by Fritsch: Model No. P-7) were put into an alumina pot and completely sealed in an argon atmosphere.
For the first few minutes, the planetary ball mill was rotated at a low speed (100 rpm) to sufficiently mix lithium sulfide, diphosphorus pentasulfide, and phosphorous tribromide. Thereafter, the rotational speed of the planetary ball mill was gradually increased to 370 rpm. A planetary ball mill is mechanically milled at 370 rpm for 20 hours, and is a powdered amorphous solid electrolyte (sulfide glass: Na ₂ S / P ₂ S ₅ / PBr ₃ = 76/19/5, MM Law). The ionic conductivity σ at room temperature of this amorphous solid electrolyte was 3.2 × 10 ⁻⁵ S / cm.
The obtained amorphous solid electrolyte was crystallized by heat treatment at 200 ° C. for 2 hours to obtain a solid electrolyte. The ionic conductivity of the solid electrolyte after the heat treatment was 1.5 × 10 ⁻³ S / cm.

  The results of Comparative Example 1-2 and Example 1-7 are summarized in Table 1 below. In addition, about the comparative example 1 and Example 5, the hydrogen sulfide concentration average value was evaluated by the following method.

[Measurement of hydrogen sulfide concentration average value (ppm)]
The measuring device shown in FIG. 2 was used.
The measurement sample was well pulverized in a mortar in a nitrogen glow box in an environment with a dew point of −80 ° C. A measurement sample (0.1 g) was sealed in a 100 ml Schlenk bottle.
Next, air (wet air) once passed through the water in the Schlenk bottle was circulated at 500 ml / min. The temperature of the wet air was 25 ° C. and the humidity was 80 to 90%.
The gas discharged from the Schlenk bottle between 1 minute and 1 minute 45 seconds after the start of distribution is collected and used as the first sample gas. Using TS-100 manufactured by Mitsubishi Chemical Analytech, sulfur content is obtained by the ultraviolet fluorescence method. The hydrogen sulfide concentration of the sample gas was calculated. The sample gas was qualitatively analyzed with a gas chromatograph using an Agilent 6890 (with a sulfur selective detector (SIEVERS 355)), and it was confirmed that the sulfur content was 99% or more of the hydrogen sulfide gas.
From the Schlenk bottle 5 minutes to 5 minutes 45 seconds after the start of distribution, 10 minutes to 10 minutes 45 seconds after the start of distribution, 20 minutes to 20 minutes 45 seconds after the start of distribution, 60 minutes to 60 minutes 45 seconds after the start of distribution The discharged gas was also measured in the same manner as the first sample gas.
The average value (ppm) of hydrogen sulfide concentration was determined from the hydrogen sulfide concentration and measurement time.

  The solid electrolyte of the present invention can be used for an electrolyte layer and an electrode layer of a battery.

1, 2 Production equipment 10 Crusher (Mechanical energy supply means)
20 Reaction tank (contact means)
22 container 24 stirring blade 26 cooling pipe 30 heater 40 oil bath 50 first connection pipe (connection means)
52 Second connecting pipe (connecting means)
54 Pump (circulation means)
60 Heat Exchanger 11 Measurement Sample 12 Schlenk Bottle 13 Flowmeter 14 Water Tank 15 Gas Collection Unit 16 Trap

Claims (14)

  A solid electrolyte containing one or more elements selected from sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium and radium, a phosphorus element, a sulfur element, and a halogen element. The solid electrolyte of Claim 1 which satisfy | fills following formula (1).
_{L a M b P c S d} X e ... (1)
(In the formula, L is one or more elements selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba and Ra.
M is one or more elements selected from B, Al, Si, Ge, Ga, In, As, Se, Sn, Sb, Te, Pb, and Bi.
X is one or more halogen elements selected from F, Cl, Br, I, and At.
a to e indicate the composition ratio of each element, and 0.1 <a ≦ 15, 0 ≦ b ≦ 3, 0 <c ≦ 5, 0 <d ≦ 15, and 0.1 <e ≦ 3. )   The solid electrolyte according to claim 2, wherein b in the formula (1) is 0 and c is 1. 4.   The solid electrolyte according to claim 2 or 3, wherein in the formula (1), 0.5≤d≤4. The solid electrolyte according to any one of claims 1 to 4, wherein the ionic conductivity at 25 ° C is 3 x 10 ^-4 Scm ^-1 or more. Any one selected from phosphorus sulfide, sulfur and phosphorus, phosphorus sulfide and sulfur, and phosphorus sulfide, sulfur and phosphorus;
The solid electrolyte according to any one of claims 1 to 5, obtained by using a compound represented by the following formula (2) and a compound represented by the following formula (3).
Q _w X _x (2)
(In the formula (2), Q is Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, B, Al, Si, P, S, Ge, Ga, In, As, One or more selected from Se, Sn, Sb, Te, Pb, and Bi.
w is any integer of 1 to 4, and x is any integer of 1 to 10.
X is one or more halogen elements selected from F, Cl, Br, I, and At. )
L _y S (3)
(In Formula (3), L is 1 or more selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra.
y is 0.5-4. )   The solid electrolyte according to claim 6, wherein Q in the formula (2) is P, and X in the formula (2) is Br, I, or Cl.   The Q in the formula (2) is Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba or Ra, and the X in the formula (2) is Br, I or Cl. The solid electrolyte according to 1.   An electrolyte sheet comprising the solid electrolyte according to claim 1.   The electrolyte sheet manufactured from the solid electrolyte in any one of Claims 1-8.   The electrode sheet containing the solid electrolyte in any one of Claims 1-8.   The electrode sheet manufactured from the solid electrolyte in any one of Claims 1-8.   The secondary battery containing the solid electrolyte in any one of Claims 1-8.   The secondary battery manufactured from the solid electrolyte in any one of Claims 1-8.

Images