JP2010030889A - Production method for lithium ion-conductive sulfide glass, production method for lithium ion-conductive sulfide glass ceramic, and mechanical milling apparatus for sulfide glass production - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method for a Li ion-conductive sulfide glass capable of producing a Li ion-conductive sulfide glass ceramic having a high ionic conductivity within a short time, to provide a production method for the Li ion-conductive sulfide glass ceramic, and to provide a mechanical milling apparatus for the sulfide glass production method desirable as a production method for a Li ion-conductive sulfide glass. <P>SOLUTION: A Li ion-conductive sulfide glass production method which is a method for producing a Li ion-conductive sulfide glass containing Li, P, and S and comprises vitrifying a raw material by mechanical milling at 60-160°C is provided. Also, a Li ion-conductive glass ceramic production method comprising heating the Li ion-conductive sulfide glass produced by the above Li ion-conductive sulfide glass production method to 200-360°C is provided. A mechanical milling apparatus for sulfide glass production comprising a grinding container, balls, and a temperature regulation means which regulates the temperature in the grinding container to 60-160°C is provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a lithium ion conductive sulfide glass, a method for producing a lithium ion conductive sulfide glass ceramic, and a mechanical milling apparatus for producing the sulfide glass.

In recent years, lithium batteries have been used as a main power source for mobile phone terminals, portable electronic devices, small household power storage devices, motorcycles using a motor as a power source, hybrid electric vehicles, and the like, and the demand for such batteries is increasing.
Currently, many of the liquid electrolytes used in lithium batteries contain flammable organic substances, which may ignite when an abnormality occurs in the battery, ensuring the safety of the battery. It is desired.
In order to construct a highly safe battery system, development of an all-solid-state lithium secondary battery using a solid electrolyte is desired.

A solid electrolyte containing a crystalline phase such as Li ₇ PS ₆ , Li ₄ P ₂ S ₆ , Li ₃ PS ₄ (eg, Patent Document 1) and a solid electrolyte containing a crystalline phase of Li ₇ P ₃ S ₁₁ (eg, Patent Document 2) discloses that lithium ion conductivity is high.
As a method for producing a solid electrolyte containing the above crystalline phase, a crystalline electrolyte is deposited by using a planetary ball mill to form a glass electrolyte at room temperature and heat treatment.
However, production of a glass electrolyte at room temperature using a planetary ball mill requires a long-time mechanical milling process, which is insufficient in productivity and economy.

Further, it is disclosed that a solid electrolyte having excellent ion conductivity can be produced by installing a rotating mill in a thermostat kept at 150 to 300 ° C. and reacting for several hours. It is disclosed that a higher temperature is preferable within the temperature range of 150 to 300 ° C. (for example, Patent Document 3).
However, even if the lithium ion conductive sulfide glass ceramic was obtained by mechanical milling treatment of lithium sulfide and phosphorus sulfide such as phosphorus pentasulfide by the method described in Patent Document 3 and further heat treatment, it was obtained. There has been a problem that lithium ion conductive sulfide glass ceramics have low ionic conductivity.

JP 2002-109955 A JP 2005-228570 A JP-A-11-144523

The present invention relates to a method for producing lithium ion conductive sulfide glass capable of producing lithium ion conductive sulfide glass ceramics having high ion conductivity in a short time, and for producing sulfide glass suitable for the production method. An object of the present invention is to provide a mechanical milling apparatus.
Another object of the present invention is to provide a method for producing a lithium ion conductive sulfide glass ceramic having high ion conductivity in a short time.

As a result of intensive studies to solve the above problems, the present inventors have obtained lithium ion conduction obtained when mechanical milling treatment of lithium sulfide and phosphorus sulfide such as phosphorus pentasulfide at a temperature higher than 160 ° C. Various crystal phases are deposited on the porous sulfide glass. Even when this lithium ion conductive sulfide glass is heat-treated to produce lithium ion conductive sulfide glass ceramics, a crystal structure other than the intended one is generated due to the influence of the various crystal phases, and the ion conductivity is lowered. I found
Based on this discovery, the present inventors have completed a method for producing a lithium ion conductive sulfide glass in which lithium sulfide and phosphorus sulfide are mechanically milled at 60 ° C. or higher and 160 ° C. or lower.

That is, the present invention is as follows.
[1] A method for producing a lithium ion conductive sulfide glass containing lithium, phosphorus and sulfur, wherein the raw material is vitrified by mechanical milling at 60 ° C. or higher and 160 ° C. or lower. A method for producing ion-conductive sulfide glass.
[2] The method for producing a lithium ion conductive sulfide glass according to [1], wherein the temperature during the mechanical milling treatment is 100 ° C. or more and 160 ° C. or less.
[3] The composition ratio of lithium, phosphorus and sulfur in the lithium ion conductive sulfide glass is 10.34 to 59.38 at% of lithium, 3.13 to 24.14 at% of phosphorus, and 16.48 to 86.53 at% of sulfur. The method for producing a lithium ion conductive sulfide glass according to [1] or [2], wherein
[4] The lithium ion conductive sulfide glass manufactured by the method for manufacturing a lithium ion conductive sulfide glass according to any one of [1] to [3] is heated at 200 ° C. or higher and 360 ° C. or lower. A method for producing a lithium ion conductive sulfide glass ceramic.
[5] A mechanical milling apparatus for producing sulfide glass, comprising a pulverizing container, a ball, and a temperature adjusting means for setting the temperature in the pulverizing container to 60 ° C. or higher and 160 ° C. or lower.

According to the present invention, a production method capable of producing lithium ion conductive sulfide glass ceramics having high ion conductivity in a short time, and a mechanical milling apparatus for producing sulfide glass suitable for the production method are provided. Can be provided.
Moreover, according to this invention, the manufacturing method of the lithium ion conductive sulfide glass ceramics which has high ion conductivity in a short time can be provided.

The time-dependent change of the value of the ionic conductivity of Examples 1-3 and Comparative Examples 1-3 is shown. The change with time of the value of the ionic conductivity of Example 4 and Comparative Example 4 is shown. The X-ray-diffraction pattern of Examples 1-3 and Comparative Examples 1-3 is shown. The X-ray-diffraction pattern of Example 4 and Comparative Example 4 is shown. 2 shows an X-ray diffraction pattern of the heat-treated product of Example 1. The X-ray-diffraction pattern of the heat processing goods of Example 4 is shown. It is the schematic diagram which showed the heating type vibration mechanical milling processing apparatus of Example 4 and Comparative Example 4. The time-dependent change of the value of the ionic conductivity of Examples 5 and 6 and Comparative Example 5 is shown. The X-ray diffraction patterns of Examples 5 and 6 and Comparative Example 5 are shown. The X-ray-diffraction pattern of the heat processing goods of Example 5 is shown.

  A method for producing a lithium ion conductive sulfide glass according to the present embodiment is a method for producing a lithium ion conductive sulfide glass containing lithium, phosphorus and sulfur by vitrification by mechanical milling, and mechanical milling. The temperature during the treatment is 60 ° C. or higher and 160 ° C. or lower.

Although it does not specifically limit as a raw material to perform a mechanical milling process, For example, lithium sulfide and phosphorus sulfide can be used.
The raw material to be mechanically milled is composed of two or more kinds of substances, and the mixture (raw material) of these substances may contain lithium, phosphorus and sulfur.
For example, if the raw materials are lithium sulfide and phosphorus sulfide, since the lithium sulfide is composed of sulfur and lithium, and the phosphorus sulfide includes sulfur and phosphorus, the raw material includes lithium, phosphorus, and sulfur.
Hereinafter, these materials will be described.

(I) Lithium sulfide (Li ₂ S)
Lithium sulfide (Li ₂ S) according to the present embodiment can be produced, for example, by the method described in Japanese Patent No. 3528866.
In this production method, lithium hydrogen sulfide and hydrogen sulfide are reacted while blowing hydrogen sulfide into an aprotic organic solvent to produce lithium hydrosulfide, and then the reaction solution is dehydrosulfurized to form lithium sulfide. It is.
Further, lithium sulfide having a purity of 99% or more is preferable.
Therefore, the lithium sulfide produced as described above can be purified by the method described in International Publication No. WO2005 / 040039.
This purification method is a method of purifying the obtained lithium sulfide by washing it at a temperature of 100 ° C. or higher using an organic solvent.
The above purification method can remove sulfur oxide, lithium N-methylaminobutyrate (hereinafter referred to as LMAB), and the like, which are impurities contained in lithium sulfide, by a simple treatment.
The total amount of sulfur oxides contained in lithium sulfide is preferably 0.15% by mass or less, and LMAB is preferably 0.1% by mass or less.

(Ii) Phosphorus sulfide Although the phosphorous sulfide according to the present embodiment is not particularly limited, phosphorous trisulfide (P ₄ S ₃ ), phosphorous pentasulfide (P ₂ S ₅ ) and phosphorous heptasulfide (P ₄ S ₇ ) are preferable. . More preferably, it is phosphorus pentasulfide.
Phosphorus pentasulfide is not particularly limited, and for example, industrially manufactured and sold products can be used.

(Iii) Composition ratio As a preferred composition ratio of the lithium ion conductive sulfide glass and / or lithium ion conductive sulfide glass ceramic, lithium is 10.34 to 59.38 at% in atomic percentage (at%), phosphorus is 3.13 to 24.14 at%, sulfur is in the range of 16.48 to 86.53 at%.
The amount of lithium sulfide and diphosphorus pentasulfide charged is 30 to 95 mol%, preferably 50 to 85 mol%, more preferably 55 to 82 mol% of the entire starting material.
Therefore, the charged amount of diphosphorus pentasulfide is 70 to 5 mol%, preferably 50 to 15 mol%, more preferably 45 to 18 mol% of the entire starting material.
When the charged amount of the raw material is within the above range, a solid electrolyte having high ionic conductivity can be synthesized.

(Iv) Solvent In this embodiment, the lithium sulfide and phosphorus sulfide may be reacted in a solvent (as a slurry), or may be reacted without using a solvent.
Here, the solvent is preferably a hydrocarbon solvent.
Although it does not restrict | limit especially as a hydrocarbon type solvent, A saturated hydrocarbon, an unsaturated hydrocarbon, or an aromatic hydrocarbon is preferable. 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.

(Iv) Mechanical milling treatment When a lithium ion conductive sulfide glass is formed using a mechanical milling treatment, the glass generation region can be expanded.
When forming lithium ion conductive sulfide glass by mechanical milling, it is preferable to use an atmosphere of an inert gas such as nitrogen.
This is because water vapor, oxygen and the like easily react with the starting material.
In the mechanical milling process, it is preferable to use a ball mill machine (planet mill machine, vibration mill machine, rotary mill machine, etc.). This is because large mechanical energy can be obtained.

(V) Mechanical milling treatment temperature The mechanical milling treatment temperature is 60 ° C or higher and 160 ° C or lower. The lower limit of the mechanical milling treatment temperature is preferably 100 ° C., and the upper limit of the mechanical milling treatment temperature is preferably 150 ° C., more preferably less than 150 ° C. More preferably, it is 140 degrees C or less.
For example, 60 to 150 ° C., 100 to 160 ° C. (preferably 100 to 150 ° C.), 60 to 150 ° C., and 100 to 150 ° C. are preferable.
When the mechanical milling treatment temperature is less than 60 ° C., the effect of shortening the reaction time required for producing the lithium ion conductive sulfide glass is small, and when the temperature is higher than 160 ° C., some crystals are formed in the lithium ion conductive sulfide glass. Phase precipitation occurs, and the lithium ion conductive sulfide glass ceramic obtained by heating the lithium ion conductive sulfide glass remains at a low level of ionic conductivity.

(Vi) Other mechanical milling treatment conditions The conditions for other mechanical milling treatments may be adjusted as appropriate depending on the equipment to be used. Generally, the faster the rotation speed, the higher the production rate of the lithium ion conductive sulfide glass. The faster the rotation time, the higher the conversion rate of the raw material to the lithium ion conductive sulfide glass.
For example, in the case of using a rotary mill which is a general pulverizer, the rotational speed may be several tens to several hundreds of revolutions / minute, and the treatment may be performed for 0.5 hours to 30 days. ) And more preferably 20 hours or more.

(Vii) Method for Producing Lithium Ion Conductive Sulfide Glass Ceramics The lithium ion conductive sulfide glass obtained as described above is further 200 ° C. to 360 ° C., preferably 220 ° C. to 320 ° C., more preferably 230 ° C. By baking at 300 ° C., the ionic conductivity is improved. If the firing temperature is outside the above range, a crystal layer with low ionic conductivity may be generated.

(Viii) Mechanical milling processing apparatus for producing sulfide glass The mechanical milling processing apparatus for producing sulfide glass of the present invention comprises a grinding container, a ball, and a temperature at which the temperature in the grinding container is 60 ° C. or higher and 160 ° C. or lower. And a pulverizer for performing mechanical milling suitable for the method for producing a lithium ion conductive sulfide glass of the present invention. For example, a planetary mill machine, a rolling mill machine, a vibration mill machine, a rotary mill machine and the like provided with the temperature adjusting means can be mentioned.

The above rotary mill machine has a larger energy applied according to the diameter of the mill, and the larger the machine, the faster the reaction speed tends to be. Large machines with an internal volume of several tens of m ³ are also commercially produced and sold. Therefore, it is a device suitable for mass production.
Further, the planetary mill machine and the vibration mill machine have an advantage that a higher energy can be applied to the sample and the reaction can be performed in a shorter time than the rotary mill machine.
The heating device provided with the temperature adjusting means for setting the temperature in the grinding container to 60 ° C. or more and 160 ° C. or less is not particularly limited as long as the temperature in the grinding container can be set to 60 ° C. or more and 160 ° C. or less. Those equipped with possible jackets or electric heaters are preferred. A known temperature controller can be used as the temperature adjusting means.

In FIG. 8, the one aspect | mode of the mechanical milling processing apparatus for sulfide glass manufacture of this invention is shown. The mechanical milling processing apparatus is a vibration mill including a mechanical milling processing container 1, an O-ring packing 2, and a heat medium jacket 3 provided on the outer periphery of the mechanical milling processing container 1, and through a heat medium supply pipe. The heat medium jacket 3 is connected to the heat medium circulation device 4.
The mechanical milling container 1 is loaded with a plurality of balls (pulverized bodies) and raw material powders, and the movement of the balls while being maintained at a predetermined temperature (60 ° C. or higher and 160 ° C. or lower) by the heat medium jacket 3. The raw material powder is crushed by the impact and frictional force of

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

The ionic conductivity and X-ray diffraction pattern in the present invention were measured by the following measuring methods.
(Ionic conductivity)
Lithium ion conductive sulfide glass or a heat-treated product thereof was filled in a tablet molding machine, and a pressure of 4 to 6 MPa was applied to form a molded body.
Next, a composite material in which carbon and lithium ion conductive sulfide glass or a heat-treated product thereof are mixed at a mass ratio of 1: 1 as an electrode is placed on both surfaces of the molded body, and pressure is applied again by a tablet molding machine. A molded body for measuring the degree (diameter of about 10 mm, thickness of about 1 mm) was produced.
About this molded object, ion conductivity measurement was implemented by alternating current impedance measurement.
The value at 25 ° C. was adopted as the value of ionic conductivity.

(X solution diffraction pattern)
X-ray diffraction measurement of lithium ion conductive sulfide glass or heat-treated product thereof was carried out using an ultrama-III X-ray generator (CuKα: λ = 1.5418４) manufactured by Rigaku Corporation.

Production example (production of lithium sulfide)
Lithium sulfide was produced according to the first invention (two-step method) of Japanese Patent No. 3528866.
That is, 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 the temperature was adjusted to 130 ° C. at 300 rpm. The temperature rose.
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 mL / min), and a part of the reacted hydrogen sulfide was dehydrosulfurized.
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 increased, but when the temperature reached 180 ° C., the temperature increase was stopped and the temperature was kept constant.
After completion of the dehydrosulfurization reaction of lithium hydrosulfide (about 80 minutes), lithium sulfide was obtained.

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

Impurity content in the obtained lithium sulfide was measured by ion chromatography.
As a result, the total content of each sulfur oxide of lithium sulfite (Li ₂ SO ₃ ), lithium sulfate (Li ₂ SO ₄ ), and lithium thiosulfate (Li ₂ S ₂ O ₃ ) is 0.13% by mass, The content of lithium N-methylaminobutyrate (NMAB) was 0.07% by mass.
The lithium sulfide thus purified was used in the following examples and comparative examples.

Example 1 (Production using a rolling mill)
Lithium sulfide of the Production Example (Li ₂ S) 32.54g (70 mole%) and phosphorus pentasulfide (P ₂ S _5; Aldrich) 67.46g (30 mole%) of 15mmφ zirconia balls about 3.6kg In a SUS pulverization container having a diameter of 114 mmφ and a capacity of 1 L.
All the above operations were carried out in the glove box, and all the instruments used were those from which moisture had been removed beforehand by a dryer.
This pulverization container was put in a thermostat kept at 140 ° C. and rotated at 103 rpm to perform mechanical milling.
Every predetermined number of days, about 1 g of a powdery product was collected and subjected to ionic conductivity measurement.
The change with time in the value of ionic conductivity is shown in Table 1 and FIG.
In FIG. 1, the vertical axis represents ion conductivity (S / cm), and the horizontal axis represents reaction time (days).
After 6 days of reaction, the ionic conductivity of the product was 1.0 × 10 ⁻⁴ S / cm or more.
Further, in the X-ray diffraction pattern (CuKα: λ = 1.5418４), the lithium sulfide peak almost disappeared, and it was confirmed that the product was glass (see FIG. 3).
In FIG. 3, the vertical axis represents Intensity (cps) and the horizontal axis represents 2θ (°).

Next, the product (lithium ion conductive sulfide glass) after the reaction for 6 days was put in a sealed container and heat-treated at 300 ° C. for 2 hours.
The X-ray diffraction pattern of this heat-treated product (lithium ion conductive sulfide glass ceramics) is 2θ = 17.8, 18.2, 19.8, 21.8 attributed to the crystal phase of Li ₇ P ₃ S _11. , 23.8, 25.9, 29.5 and 30.0 deg were observed (see FIG. 5).
In FIG. 5, the vertical axis represents Intensity (cps), and the horizontal axis represents 2θ (°).
As a result of measuring the ionic conductivity, the ionic conductivity of this heat-treated product was 1.5 × 10 ⁻³ S / cm.

Example 2
The reaction and treatment were performed in the same manner as in Example 1 except that the pulverization container was placed in a constant temperature bath maintained at 100 ° C. and subjected to mechanical milling.
The ionic conductivity of the product reached 1.0 × 10 ⁻⁴ S / cm after 8 days of reaction.
In the X-ray diffraction pattern, it was confirmed that the lithium sulfide peak almost disappeared and the product was glass.
The time course of ionic conductivity values is shown in Table 1 and FIG. 1, and the X-ray diffraction pattern of the product after 8 days is shown in FIG.

Next, when the product (lithium ion conductive sulfide glass) after the reaction for 8 days was heat treated in the same manner as in Example 1, the X-ray diffraction pattern of the heat treated product (lithium ion conductive sulfide glass ceramics) was Li Peaks are observed at 2θ = 17.8, 18.2, 19.8, 21.8, 23.8, 25.9, 29.5, 30.0 deg, which are attributed to the crystal phase of ₇ P ₃ S _11. It was.
As a result of measuring the ionic conductivity, the ionic conductivity of this heat-treated product was 1.3 × 10 ⁻³ S / cm.

Example 3
The reaction and treatment were performed in the same manner as in Example 1 except that the pulverization container was placed in a thermostat kept at 70 ° C. and subjected to mechanical milling.
The ionic conductivity of the product was 1.0 × 10 ⁻⁴ S / cm or more after 10 days of reaction.
In the X-ray diffraction pattern, it was confirmed that the lithium sulfide peak almost disappeared and the product was glass.
The time-dependent change in the value of ionic conductivity is shown in Table 1 and FIG. 1, and the X-ray diffraction pattern is shown in FIG.

Next, when the product (lithium ion conductive sulfide glass) after the reaction for 10 days was heat-treated in the same manner as in Example 1, the X-ray diffraction pattern of the heat-treated product (lithium ion conductive sulfide glass ceramics) was Li Peaks are observed at 2θ = 17.8, 18.2, 19.8, 21.8, 23.8, 25.9, 29.5, 30.0 deg, which are attributed to the crystal phase of ₇ P ₃ S _11. It was.
As a result of measuring the ionic conductivity, the ionic conductivity of this heat-treated product was 1.6 × 10 ⁻³ S / cm.

Comparative Example 1
The reaction and treatment were carried out in the same manner as in Example 1 except that the pulverization container was placed in a thermostat kept at 30 ° C. and subjected to mechanical milling treatment.
The ionic conductivity of the product reached 1.0 × 10 ⁻⁴ S / cm after 16 days of reaction.
In the X-ray diffraction pattern, it was confirmed that the lithium sulfide peak almost disappeared and the product was glass.
The time-dependent change in the value of ionic conductivity is shown in Table 1 and FIG. 1, and the X-ray diffraction pattern is shown in FIG.
Next, when the product after the reaction for 16 days was heat-treated in the same manner as in Example 1, the X-ray diffraction pattern of the heat-treated product was 2θ = 17.8, 18 belonging to the crystal phase of Li ₇ P ₃ S _11. Peaks were observed at .2, 19.8, 21.8, 23.8, 25.9, 29.5, 30.0 deg.
As a result of measuring the ionic conductivity, the ionic conductivity of this heat-treated product was 1.8 × 10 ⁻³ S / cm.

Comparative Example 2
The reaction and treatment were performed in the same manner as in Comparative Example 1 except that the pulverization container was placed in a thermostat kept at 170 ° C. and subjected to mechanical milling.
The ionic conductivity of the product reached 4.5 × 10 ⁻⁵ S / cm by the reaction for 3 days, but no improvement in ionic conductivity was observed even when the reaction was continued thereafter.
In the X-ray diffraction pattern of the product after the reaction for 3 days, a peak attributed to Li ₃ PS ₄ was observed.
The time-dependent change in the value of ionic conductivity is shown in Table 1 and FIG. 1, and the X-ray diffraction pattern is shown in FIG.
Next, the product after the reaction for 3 days was heat-treated in the same manner as in Example 1, and the ion conductivity of the heat-treated product was measured. As a result, the ion conductivity was 8.7 × 10 ⁻⁵ S / cm.

Comparative Example 3
The reaction and treatment were performed in the same manner as in Example 1 except that the pulverization container was placed in a thermostat kept at 200 ° C. and subjected to mechanical milling.
Although the ionic conductivity of the product was 7.0 × 10 ⁻⁶ S / cm or more after the reaction for 3 days, the ionic conductivity was not improved even when the reaction was continued thereafter.
In the X-ray diffraction pattern of the product after the reaction for 3 days, a peak attributed to Li ₃ PS ₄ was observed.
The time-dependent change in the value of ionic conductivity is shown in Table 1 and FIG. 1, and the X-ray diffraction pattern is shown in FIG.
Next, when the product after the reaction for 3 days was heat-treated in the same manner as in Example 1, in the X-ray diffraction pattern of the heat-treated product, a peak attributed to Li ₃ PS ₄ as a main crystal was observed.
As a result of measuring the ionic conductivity, the heat conductivity of this heat-treated product was 9.2 × 10 ⁻⁶ S / cm.

Example 4 (Production using a vibration mill)
In this example, a heating type vibration mill shown in FIG. 7 was used.
That is, vibration mechanical milling was performed using a SUS container with a cylindrical jacket with a capacity of 6.7 L as a grinding container.
In a 6.7 L container, 18.2 kg of 20 mmφ zirconia balls, 81.35 g (70 mol%) of lithium sulfide (Li ₂ S) and phosphorus pentasulfide (P ₂ S ₅ ; manufactured by Aldrich) of the above production example, 168.65 g ( 30 mol%) was charged and sealed in a dry room kept at a dew point of -40 ° C or lower.
A hermetic container was fixed to the vibration mill, a heating medium at 120 ° C. was circulated in the jacket, and mechanical milling was performed at a frequency of 1500 times per minute with an amplitude of 8 mm.
About 1 g of a powdery product was sampled at predetermined time intervals, and ionic conductivity was measured.
The changes over time in the value of ionic conductivity are shown in Table 2 and FIG.
In FIG. 2, the vertical axis represents ion conductivity (S / cm), and the horizontal axis represents reaction time (hours).
After 20 hours of reaction, the ionic conductivity of the product reached 1.0 × 10 ⁻⁴ S / cm.
Further, in the X-ray diffraction pattern (CuKα: λ = 1.5418４), the lithium sulfide peak almost disappeared, and it was confirmed that the product was glass (see FIG. 4).
In FIG. 4, the vertical axis indicates Intensity (cps), and the horizontal axis indicates 2θ (°).

Next, the product (lithium ion conductive sulfide glass) after the reaction for 20 hours was put in a sealed container and heat-treated at 300 ° C. for 2 hours.
The X-ray diffraction pattern of this heat-treated product (lithium ion conductive sulfide glass ceramics) is 2θ = 17.8, 18.2, 19.8, 21.8 attributed to the crystal phase of Li ₇ P ₃ S _11. , 23.8, 25.9, 29.5 and 30.0 deg were observed (see FIG. 6).
In FIG. 6, the vertical axis represents Intensity (cps) and the horizontal axis represents 2θ (°).
As a result of measuring the ionic conductivity, the ionic conductivity of this heat-treated product was 1.8 × 10 ⁻³ S / cm.

Comparative Example 4
The reaction and treatment were carried out in the same manner as in Example 4 except that a heating medium at 40 ° C. was circulated through the jacket.
The ionic conductivity of the product was 1.0 × 10 ⁻⁴ S / cm or more after 40 hours of reaction.
The time-dependent change in the value of ion conductivity is shown in Table 2 and FIG. 2, and the X-ray diffraction pattern is shown in FIG.
Further, in the X-ray diffraction pattern (CuKα: λ = 1.5418４), the lithium sulfide peak almost disappeared, and it was confirmed that the product was glass (see FIG. 4).

Example 5
The reaction was conducted under the same conditions as in Example 1 except that 100 g of xylene (dehydrated grade) manufactured by Wako Pure Chemical Industries, Ltd. was added. The xylene slurry of the reaction product taken out was dried under vacuum conditions at 140 ° C. for 2 hours to obtain a powder product. The results of the change in conductivity are shown in Table 3 and FIG. After 4 days of reaction, the product had an ionic conductivity of 1.0 × 10 ⁻⁴ S / cm or more.
Further, in the X-ray diffraction pattern (CuKα: λ = 1.5418４), the lithium sulfide peak almost disappeared, and it was confirmed that the product was glass (see FIG. 9).
Next, the product (lithium ion conductive sulfide glass) after the reaction for 4 days was put in a sealed container and heat-treated at 300 ° C. for 2 hours.
The X-ray diffraction pattern of this heat-treated product (lithium ion conductive sulfide glass ceramics) is 2θ = 17.8, 18.2, 19.8, 21.8 attributed to the crystal phase of Li ₇ P ₃ S _11. , 23.8, 25.9, 29.5 and 30.0 deg were observed (see FIG. 10).
As a result of measuring the ionic conductivity, the ionic conductivity of this heat-treated product was 1.2 × 10 ⁻³ S / cm.

Example 6
The reaction was performed under the same conditions as in Example 2 except that 100 g of toluene (dehydrated grade) manufactured by Wako Pure Chemical Industries, Ltd. was added. The taken out toluene slurry of the reaction product was dried at 140 ° C. for 2 hours under vacuum conditions to obtain a powder product. The results of the change in conductivity are shown in Table 3 and FIG. After 6 days of reaction, the ionic conductivity of the product was 1.0 × 10 ⁻⁴ S / cm or more.
Further, in the X-ray diffraction pattern (CuKα: λ = 1.5418４), the lithium sulfide peak almost disappeared, and it was confirmed that the product was glass (see FIG. 9).
Next, the product (lithium ion conductive sulfide glass) after the reaction for 6 days was put in a sealed container and heat-treated at 300 ° C. for 2 hours.
The X-ray diffraction pattern of this heat-treated product (lithium ion conductive sulfide glass ceramics) is 2θ = 17.8, 18.2, 19.8, 21.8 attributed to the crystal phase of Li ₇ P ₃ S _11. , 23.8, 25.9, 29.5, 30.0 deg.
As a result of measuring the ionic conductivity, the ionic conductivity of this heat-treated product was 1.4 × 10 ⁻³ S / cm.

Comparative Example 5
The reaction was carried out under the same conditions as in Comparative Example 2 except that 100 g of decalin made by Wako Pure Chemicals was dehydrated with 3A molecular sieves was added. Toluene was added to the decalin slurry of the reaction product taken out and solid-liquid separated to replace decalin with toluene, and then dried under vacuum conditions at 140 ° C. for 2 hours to obtain a powder product. The results of the change in conductivity are shown in Table 3 and FIG. After the reaction for 2 days, the conductivity remained at a low level, and precipitation of a crystal phase containing Li ₃ PS ₄ was observed.

The glass ceramic obtained by the production method of the present invention exhibits an extremely high lithium ion conductivity of 10 ⁻³ S / cm ^{1 at} 25 ° C. Therefore, it is extremely suitable as a material for a solid electrolyte of a lithium battery.
Moreover, the all-solid-state battery using the ceramics as a solid electrolyte has a high energy density, and is excellent in safety and charge / discharge cycle characteristics.

DESCRIPTION OF SYMBOLS 1 Mechanical milling processing container 2 O-ring packing 3 Heat-medium jacket 4 Heat-medium circulation apparatus

Claims (5)

A method for producing a lithium ion conductive sulfide glass containing lithium, phosphorus and sulfur,
A method for producing a lithium ion conductive sulfide glass, wherein the raw material is vitrified by mechanical milling at 60 ° C or higher and 160 ° C or lower.   2. The method for producing a lithium ion conductive sulfide glass according to claim 1, wherein the temperature during the mechanical milling treatment is 100 ° C. or more and 160 ° C. or less.   The composition ratio of lithium, phosphorus and sulfur in the lithium ion conductive sulfide glass is 10.34 to 59.38 at% lithium, 3.13 to 24.14 at% phosphorus, and 16.48 to 85.53 at% sulfur. The method for producing a lithium ion conductive sulfide glass according to claim 1 or 2.   A lithium ion conductive sulfide glass produced by the method for producing a lithium ion conductive sulfide glass according to any one of claims 1 to 3, wherein the lithium ion conductive sulfide glass is heated at 200 ° C or higher and 360 ° C or lower. A method for producing ion-conductive sulfide glass ceramics. A crushing container;
With the ball,
Temperature adjusting means for adjusting the temperature in the pulverization vessel to 60 ° C. or higher and 160 ° C. or lower;
A mechanical milling apparatus for producing sulfide glass, comprising:

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