JP2014234212A - Production method of sulfide compound storage container - Google Patents

Abstract

In manufacturing a storage container for storing a sulfide compound that easily reacts with moisture, it is possible to prevent the sulfide compound from reacting with moisture remaining in the container and reducing the purity during storage. Provided is a method for producing a sulfide compound storage container. A storage container having an inlet and an outlet is formed into a predetermined shape, and after the inside of the storage container is washed with pure water, a dry gas is introduced into the container from the inlet. The inside of the storage container is dried until the dry gas flowing out from the outflow port has a dew point of −30 ° C. or lower. [Selection figure] None

Description

  The present invention relates to a method for producing a sulfide compound storage container for storing a sulfide compound that easily reacts with moisture.

  In recent years, there has been an increasing demand for lithium batteries that are used as main power sources 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. Currently, many of the solid electrolytes used in lithium batteries contain flammable organic substances, so there is a risk of fire when an abnormality occurs in the battery, ensuring the safety of the battery. It is desired. In order to construct a safer battery system, development of an all-solid-state lithium battery using a solid electrolyte is desired.

  A sulfide-based solid electrolyte has been studied as a non-flammable solid electrolyte. For example, lithium sulfide and other sulfides such as phosphorus sulfide, silicon sulfide, boron sulfide, and germanium sulfide are added with an organic solvent. It is known to produce a sulfide-based solid electrolyte by reacting (see, for example, Patent Documents 1 and 2).

  However, when manufacturing an all-solid-state lithium battery using a sulfide-based solid electrolyte, the sulfide-based solid electrolyte, lithium sulfide used as a raw material thereof, and the like easily react with moisture, and there is a risk of generating hydrogen sulfide. There is a problem in handling and storage.

  Further, regarding the preservation of alkali metal compounds that easily react with moisture, for example, Patent Document 3 discloses an alkali metal dispersion that can be safely stored, transported, and redispersed without decomposition of the alkali metal dispersion. Transport containers have been proposed. And patent document 4 has the description regarding preservation | save of the borazine compound which reacts easily with a water | moisture content.

JP 2010-140893 A JP 2012-043646 A JP 2002-193382 A JP 2008-110940 A

  However, in Patent Document 3, after completely removing moisture from the inside of the container and completely replacing it with an inert gas, the container is filled with an alkali metal dispersion, so that the container is filled with outside air, other chemicals, etc. The alkali metal dispersion is prevented from deteriorating due to the intrusion of water, but nothing is shown about a specific operation for removing moisture from the inside of the container. Patent Document 4 does not describe any sulfide-based compounds.

  The present invention has been made in view of the above circumstances, and in producing a storage container for storing a sulfide compound that easily reacts with moisture, the sulfide compound remains in the container during storage. It aims at providing the manufacturing method of the container for a sulfide type compound which can suppress that the purity will reduce by reacting.

  In the method for producing a sulfide-based compound storage container according to the present invention, in manufacturing a storage container for storing a sulfide-based compound, the storage container having an inlet and an outlet is in a predetermined form. A step of cleaning the inside of the storage container with pure water, a dry gas flowing out from the outlet while flowing into the container from the inlet, and a dry gas flowing out from the outlet is And a step of drying the inside of the storage container until the dew point is −30 ° C. or lower.

In the method for producing a sulfide-based compound storage container according to the present invention, it is preferable that each element except oxygen has a composition represented by the following formula (1).
_{L a M b P c S d} X e ... (1)
(In the formula, L represents an alkali metal, M represents one or more elements selected from B, Al, Si, Ge, As, Se, Sn, Sb, Te, Pb and Bi, and X represents I, Cl, 1 or more halogen elements selected from Br and F. a to e satisfy the following formulas: 0 <a ≦ 12, 0 ≦ b ≦ 0.2, c = 1, 0 <d ≦ 9, 0 <e ≦ 9)

  Further, by applying the present invention, the storage container can be processed into a state suitable for storing the sulfide-based compound. Such a processing method is a method for processing a storage container for storing a sulfide-based compound into a state suitable for storage of a sulfide-based compound, wherein the storage container having an inlet and an outlet is provided. The step of preparing, the step of washing the inside of the storage container with pure water, the dry gas flowing out from the outlet while allowing the dry gas to flow into the container from the inlet, The method for treating a sulfide-based compound storage container includes a step of drying the inside of the storage container until the dew point is −30 ° C. or lower.

  According to the present invention, since a storage container can be produced in such a way that no moisture remains in the container, the sulfide compound reacts with the water remaining in the container during storage, and the purity is reduced. Can not be.

  Hereinafter, a method for producing a sulfide compound storage container according to the present invention will be described.

The sulfide-based compound stored in the storage container manufactured according to the present invention is not particularly limited. For example, it is preferable that each element except oxygen has a composition represented by the following formula (1). It is more preferable that all the elements included are solid electrolyte glass or glass ceramic having a composition represented by the following formula (1).
_{L a M b P c S d} X e ... (1)
(In the formula, L represents an alkali metal, M represents one or more elements selected from B, Al, Si, Ge, As, Se, Sn, Sb, Te, Pb and Bi, and X represents I, Cl, 1 or more halogen elements selected from Br and F. a to e satisfy the following formulas: 0 <a ≦ 12, 0 ≦ b ≦ 0.2, c = 1, 0 <d ≦ 9, 0 <e ≦ 9)

The solid electrolyte glass can be synthesized using, for example, the following raw materials (A), (B), and (C).
(A) an alkali metal sulfide (B) M _'m S compounds represented by _{n (C) M "w X} y compound represented by (wherein, M' is B, Al, Si, P, Ge, M ″ represents Li, Na, B, Al, Si, P, S, Ge, As, Se, Sn, Sb, Te, Pb, or Bi, X represents F, Cl, Br, or I. w represents 1. ) Represents an integer of ˜2, and m, n, and y represent integers of 1 to 10.)

Examples of the raw material (A) include Li ₂ S (lithium sulfide) and Na ₂ S (sodium sulfide). Of these, lithium sulfide is preferable.
Lithium sulfide can be used without particular limitation, but high purity is preferred. Lithium sulfide can be produced, for example, by the methods described in JP-A-7-330312, JP-A-9-283156, JP-A 2010-163356, and Japanese Patent Application No. 2009-233892.

Specifically, lithium hydroxide and hydrogen sulfide are reacted at 70 ° C. to 300 ° C. in a hydrocarbon-based organic solvent to produce lithium hydrosulfide, and then the reaction solution is dehydrosulfurized to form lithium sulfide. Can be synthesized (Japanese Patent Laid-Open No. 2010-163356).
In addition, lithium hydroxide and hydrogen sulfide are reacted at 10 ° C. to 100 ° C. in an aqueous solvent to produce lithium hydrosulfide, and then the reaction liquid is dehydrosulfurized to synthesize lithium sulfide (special feature). Application 2009-238952).

  The lithium sulfide preferably has a total lithium oxide lithium salt content of 0.15% by mass or less, more preferably 0.1% by mass or less, and a lithium N-methylaminobutyrate content. The content is preferably 0.15% by mass or less, more preferably 0.1% by mass or less. When the total content of the lithium salt of sulfur oxide is 0.15% by mass or less, the solid electrolyte obtained by the melt quenching method or the mechanical milling method becomes a glassy electrolyte (fully amorphous). On the other hand, when the total content of the lithium salt of sulfur oxide exceeds 0.15% by mass, the obtained electrolyte may become a crystallized product from the beginning.

  In addition, when the content of lithium N-methylaminobutyrate is 0.15% by mass or less, a deteriorated product of lithium N-methylaminobutyrate does not deteriorate the cycle performance of the lithium ion battery. When lithium sulfide with reduced impurities is used, a high ion conductive electrolyte can be obtained.

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

As raw materials (B), P ₂ S ₃ (phosphorus trisulfide), P ₂ S ₅ (phosphorus pentasulfide), SiS ₂ (silicon sulfide), Al ₂ S ₃ (aluminum sulfide), GeS ₂ (germanium sulfide) ), B ₂ S ₃ (diarsenic trisulfide), or the like can be used. P ₂ S ₅ is preferable. P ₂ S ₅ can be used without particular limitation as long as it is industrially manufactured and sold.
In addition, you may use a raw material (B) in mixture of 2 or more types.

As the compound containing a halogen element _{(C), LiF, LiCl,} LiBr, LiI, BCl 3, BBr 3, BI 3, 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, PF 3, PF 5, PCl 3, PCl 5, PBr 3, PI 3, P 2 Cl 4, P 2 I 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 B _{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 , NaI, NaF, NaCl, NaBr and the like can be mentioned. Preferred is a compound in which M ″ is lithium or phosphorus. Specifically, LiCl, LiBr, LiI, PCl ₅ , PCl ₃ , PBr ₅ and PBr ₃ are preferred, and LiCl, LiBr, LiI and PBr ₃ are more preferred. It is.

In addition to the raw materials (A) to (C), a compound (vitrification accelerator) for reducing the glass transition temperature may be added as the raw material (D). Examples of vitrification promoters include Li ₃ PO ₄ , Li ₄ SiO ₄ , Li ₄ GeO ₄ , Li ₃ BO ₃ , Li ₃ AlO ₃ , Li ₃ CaO ₃ , Li ₃ InO ₃ , Na ₃ PO ₄ , Na Examples include inorganic compounds such as ₄ SiO ₄ , Na ₄ GeO ₄ , Na ₃ BO ₃ , Na ₃ AlO ₃ , Na ₃ CaO ₃ , and Na ₃ InO ₃ .

In addition to the raw materials (A) to (D), simple phosphorus (P), simple sulfur (S), silicon (Si), LiBO ₂ (lithium metaborate), LiAlO ₃ (lithium aluminate), Na ₂ S (sodium sulfide), NaBO ₂ (sodium metaborate), NaAlO ₃ (sodium aluminate), POCl ₃ , POBr _{3 and the} like can also be used.

The solid electrolyte glass has a composition represented by the following formula (1 ′) of each element containing oxygen, for example, when oxygen enters with a vitrification accelerator, a halogen compound containing oxygen, lithium sulfite, or the like.
_{L a M b P c S d} X e O f ... (1 ')
(In the formula, L represents an alkali metal, M represents one or more elements selected from B, Al, Si, Ge, As, Se, Sn, Sb, Te, Pb and Bi, and X represents I, Cl, One or more halogen elements selected from Br and F are shown.
a to e each satisfy the following formula.
0 <a ≦ 12, 0 ≦ b ≦ 0.2, c = 1, 0 <d ≦ 9, 0 <e ≦ 9, 0 <f ≦ 9)

The solid electrolyte glass is a sulfide-based glass having the composition represented by the above-described formula (1), but the composition can be controlled by adjusting the mixing ratio of the raw materials (A) to (D).
The mixing ratio of the components (A), (B), and (C) depends on whether M ″ of the component (C) is phosphorus or other than phosphorus.
When M ″ of component (C) is other than phosphorus, for example, the molar ratio of component (A) :( B) is 65:35 to 85:15, preferably (A) :( B) = 67: 33 83:17 (molar ratio), more preferably (A) :( B) = 68: 32-80: 20 (molar ratio), most preferably (A) :( B) = 75: 25 -79: 21 (molar ratio).
At this time, the ratio of the molar amount of (C) to the total molar amount of components (A) and (B) is preferably 50:50 to 99: 1, more preferably [(A) + ( B)] :( C) = 55: 45 to 97: 3 (molar ratio), more preferably [(A) + (B)] :( C) = 60: 40 to 96: 4 (molar ratio). Especially preferably, [(A) + (B)] :( C) = 70: 30 to 96: 4 (molar ratio).

When M ″ of component (C) is phosphorus, for example, the molar ratio of component (A) :( B) is 60:40 to 90:10, preferably (A) :( B) = 70: 30 To 90:10 (molar ratio), more preferably (A) :( B) = 72: 28 to 88:12 (molar ratio), and still more preferably (A) :( B) = 74: 26. To 86:14 (molar ratio), particularly preferably (A) :( B) = 75: 25 to 85:15 (molar ratio), most preferably component (A) is lithium sulfide, Component (B) diphosphorus pentasulfide, (A) :( B) = 77: 23 to 83:17 (molar ratio).
At this time, the ratio of the molar amount of (C) to the total molar amount of components (A) and (B) is preferably 50:50 to 99: 1, more preferably [(A) + ( B)] :( C) = 80: 20 to 98: 2 (molar ratio), more preferably [(A) + (B)] :( C) = 85: 15 to 98: 2 (molar ratio). Particularly preferably, [(A) + (B)] :( C) = 90: 10 to 98: 2.

The blending amount of the raw material (D) (vitrification accelerator) is preferably 1 to 10 mol%, particularly 1 to 5 mol%, based on the total of the raw materials (A), (B) and (C). It is preferable that
In addition, the solid electrolyte glass of this invention may consist of the said raw material (A)-(C) and the raw material (D) arbitrarily, and may consist only of these components. “Substantially” means that the composition is mainly composed of the raw materials (A) to (C) and optionally the raw material (D). For example, the raw materials (A) to (D) are the raw materials. It means 95% by weight or more or 98% by weight or more based on the whole.

The solid electrolyte glass ceramic is obtained by heat-treating the above-described solid electrolyte glass at a temperature not lower than the normal glass transition temperature.
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. There is no specific specification for the temperature raising method. The temperature may be raised slowly to a predetermined temperature or heated rapidly. 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 atmospheric pressure during heating may be a normal pressure or a reduced pressure. The atmosphere may be in the air or an inert atmosphere.

The solid electrolyte glass ceramic thus obtained has high ionic conductivity, for example, 1 × 10 ⁻³ S / cm or more, more preferably 1.5 × 10 ⁻³ S / cm or more. it can. The all-solid-state lithium battery described in the background art can achieve a high output by being manufactured using such a solid electrolyte glass ceramic exhibiting high ionic conductivity.

In the present invention, when manufacturing a storage container for storing the above-described sulfide-based compound, first, a container having an inlet and an outlet is formed in a predetermined form.
The specific form of the storage container, such as the size and shape, is not particularly limited as long as it does not hinder the storage of the sulfide-based compound in a warehouse or transportation during shipment. . When storing a small amount of a sulfide-based compound synthesized on a laboratory scale, for example, a relatively small volume of about 10 L can be obtained. When storing a large amount of sulfide-based compounds synthesized on an industrial scale, for example, a relatively large capacity of about 200 L can be achieved. Also, the shape thereof can be appropriately designed in consideration of the storage location, the transport means, etc., for example, as the same shape as a reagent bottle, a drum can, and the like.
A sealable valve is attached to each of the inlet and outlet provided in the storage container.

  Further, the storage container is preferably 0.1 MPa or more, more preferably 0.2 MPa or more, and still more preferably, in order to prevent the atmosphere at that time from entering the container when storing the sulfide-based compound. Is formed to have a pressure resistance of 0.3 MPa or more. When the pressure resistance of the storage container is less than 0.1 MPa, the atmosphere during storage of the sulfide compound enters the container, and the sulfide compound decomposes or reacts by contact with moisture contained in the atmosphere. There is a fear.

  There is no upper limit to the pressure resistance of the storage container considering only the prevention of the intrusion of the atmosphere, but if the pressure resistance is increased more than necessary, the container becomes heavy and inconvenient to handle, and the manufacturing cost will increase. Problem arises. Considering the balance with such a problem, the pressure resistance of the storage container is preferably 2.0 MPa or less, more preferably 0.5 MPa or less.

  In the present invention, “pressure-resistant pressure” refers to the intrusion of the atmosphere into the inside of the container when the pressure of the atmosphere is increased by placing a sealed storage container in an atmosphere under a certain pressure. The pressure that can withstand. In the present invention, in a temperature environment of 23 ° C., the inside of the container with the leak valve is filled with dry gas, and when the dry gas filled in the container starts to leak from the leak valve. The “pressure resistance” is obtained by measuring the filling pressure and subtracting the atmospheric pressure from the measured value.

  Such a storage container can be manufactured using, for example, a metal material such as stainless steel or hastelloy, or a plastic material such as polytetrafluoroethylene (PTFE). The material for the storage container is not limited to these as long as a desired pressure-resistant pressure can be obtained, but stainless steel is preferably used because it is superior in improving the pressure-resistant pressure.

  In order to improve the corrosion resistance of the storage container, the inner surface of the container can be coated with a resin. Although the resin for coating is not particularly limited, for example, polytetrafluoroethylene (PTFE), polypropylene and the like can be exemplified, and PTFE is preferably used because it is superior in improving corrosion resistance. When the inner surface of the container is coated with a resin, the coating thickness is preferably 10 to 3000 μm, more preferably 500 to 1000 μm.

In the present invention, after the storage container is formed in a predetermined form as described above, a cleaning process is performed in which the inside of the container is cleaned with pure water.
In the present invention, “pure water” refers to water having an electrical conductivity of 1 mS / m or less in a temperature environment of 25 ° C. Such “pure water” can be prepared by using a commercially available pure water production apparatus. The electrical conductivity at 25 ° C. is preferably 0.5 mS / m or less, more preferably 0. .1 mS / m or less, more preferably 0.05 mS / m or less. The amount of silica contained as an impurity is preferably 50 μg / L or less, more preferably 5 μg / L or less, and still more preferably 0.5 μg / L or less.

  Prior to washing the storage container with pure water, the inside of the container is washed 1 to 3 times with an organic solvent such as isopropyl alcohol, hexane, or toluene in order to remove organic substances adhering to the container. Is preferred.

Next, in the present invention, after cleaning the inside of the container with pure water, the valves attached to the inlet and the outlet provided in the storage container are opened, and the dry gas is allowed to flow into the container from the inlet. A drying process is performed in which the inside of the container is dried out of the outlet.
The environment of the atmosphere at this time is not particularly limited, but the temperature of the atmosphere is preferably 10 to 30 ° C, and more preferably 20 to 25 ° C. The cleanness of the atmosphere is preferably 1000 or less, more preferably 100 or less, still more preferably 10 or less, and particularly preferably 1 or less.
The cleanness refers to the number of fine particles having a size of 0.5 μm or more existing in one cubic foot, and can be measured using a commercially available particle counter.

  The drying gas used for drying the inside of the storage container is not particularly limited. Although air may be used, it is preferable to use an inert gas such as nitrogen, argon or helium, and it is particularly preferable to use nitrogen that is industrially available.

When the dry gas flows into the container from the inlet, it is preferable that the dry gas to be introduced is dried through a desiccant such as silica gel. A dry gas having a dew point measured using a commercially available dew point meter is preferably −50 ° C. or lower, more preferably −70 ° C. or lower, is allowed to flow into the container. The oxygen content in the dry gas to be introduced is preferably 1 ppm or less, and it is preferable to remove the particulate impurities through the filter and then flow into the container.
The flow rate for flowing drying gas inside the container is preferably 0.001~10m ³ / h, more preferably 0.01~5m ³ / h, particularly preferably 0.1 to 1 m ³ / h.

On the other hand, the dry gas flowing out from the outlet has a dew point higher than that of the dry gas introduced from the inlet because the moisture in the storage container is taken in.
In the present invention, the dew point of the dry gas flowing out from the inlet is measured with a commercially available dew point meter, and the dry gas is stored until the dew point is −30 ° C. or lower, preferably −40 ° C. or lower, more preferably −50 ° C. or lower. Dry the inside of the container. The time required for drying the storage container is preferably 0.05 to 1 hour, more preferably 0.1 to 0.5 hour in order to shorten the process, and any method such as heat drying or drying under reduced pressure. The drying time can also be shortened by combining the above.

  When drying until the dew point of the dry gas flowing out from the outlet is equal to or less than the above value, the moisture adsorbed in the container is removed, and it becomes possible to suppress the decomposition or reaction of the sulfide-based compound due to the moisture. . Thereby, even when the sulfide compound is stored for a long period of time, the purity of the sulfide compound in the container can be maintained.

Thus, in the present invention,
(1) forming a storage container having an inlet and an outlet in a predetermined form;
(2) a step of washing the inside of the storage container with pure water;
(3) A process of drying the inside of the storage container until the dry gas flowing out from the outlet is dew point -30 ° C. or lower while allowing the dry gas to flow into the container from the inlet,
To produce a sulfide compound storage container. The sulfide-based compound storage container thus manufactured may store the sulfide-based compound alone, or may be stored in a state dissolved or dispersed in an appropriate solvent or the like.

According to the present invention as described above, a sulfide compound storage container can be produced in such a manner that no moisture remains in the container. For this reason, reaction with the water | moisture content which remains in a container can be avoided effectively, and the purity of the sulfide type compound preserve | saved in the container can be maintained. That is, the decomposition or reaction of the sulfide-based compound stored in the container is suppressed during the period from when the synthesized sulfide-based compound is filled and sealed in the container to when it is taken out from the container and used. A decrease in the purity of the physical compound can be suppressed very well. For example, the decrease in ionic conductivity when stored for 30 days is within an order of magnitude, more specifically, 1 × 10 ⁻³ S / cm can maintain 1 × 10 ⁻⁴ S / cm or more, The thing of * 10 < ^-4 > S / cm can maintain 1 * 10 < ^-5 > S / cm or more.

  In producing an all-solid-state lithium battery as described in the background art, the purity of the sulfide-based compound as a material is preferably 97% by mass in order to improve the quality of products such as solid electrolytes and electrode composites. As mentioned above, More preferably, it is 98 mass% or more. According to the present invention, it is possible to preserve such high purity.

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

[Example]
A mixture obtained by adding 39.05 g (70 mol%) of lithium sulfide, 80.95 g (30 mol%) of diphosphorus pentasulfide and 1080 g of dehydrated toluene was charged into a reaction vessel and a mill, and in the same manner as in Example 1 of Patent Document 2, A sulfide-based solid electrolyte slurry solution before drying treatment was obtained. This operation was repeated 10 times to prepare about 12 L of a sulfide-based solid electrolyte slurry solution.
A part was taken out as a sample, dried at 150 ° C., and then subjected to heat treatment under reduced pressure at 300 ° C. for 2 hours. The ionic conductivity of the sulfide-based solid electrolyte was measured by the AC impedance method (measurement frequency: 100 Hz to 15 MHz). ) Showed 3.0 × 10 ⁻³ S / cm at room temperature.

On the other hand, a stainless storage container having a capacity of 20 L and having an inlet and an outlet provided with a sealable valve was formed in a predetermined form. The pressure resistance of the obtained storage container was 0.5 MPa. The inside of the storage container was washed with pure water having an electric conductivity of 0.05 mS / m at 25 ° C. and dried at room temperature for half a day.
Next, the valves attached to the inlet and outlet provided in the storage container are opened, and nitrogen gas (dry gas) with a dew point of −70 ° C. flows into the container at a flow rate of 0.6 m ³ / h from the inlet. The inside of the container was dried by continuing to flow in the dry gas until the dew point of nitrogen gas flowing out from the outlet became −40 ° C.
In addition, the dew point of nitrogen gas was measured using a commercially available online dew point meter (manufactured by Nagano Denki Sangyo Co., Ltd.).

The storage container thus produced was filled with about 12 L of the sulfide-based solid electrolyte slurry solution described above, the valve was sealed, and the container was stored at room temperature for 30 days. After storage, the content of the sample amount is taken out from the storage container, dried at 150 ° C., and then subjected to heat treatment while reducing pressure at 300 ° C. for 2 hours. The ionic conductivity of the sulfide-based solid electrolyte obtained is as follows. When measured by an alternating current impedance method (measurement frequency: 100 Hz to 15 MHz), it showed 2.8 × 10 ⁻³ S / cm at room temperature, and it was confirmed that the sample was not deteriorated.

[Comparative example]
The ionic conductivity of the sulfide-based solid electrolyte after storage was measured in the same manner as in the example except that the washing step and the drying step were omitted and the storage container was produced, and 1.0 × 10 ⁻⁴ at room temperature. S / cm was shown, confirming deterioration.

  Although the present invention has been described with reference to the preferred embodiment, it is needless to say that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. .

  For example, in the above-described embodiment, the example in which the storage container is manufactured through the washing process and the drying process following the process of forming the storage container in a predetermined form has been described, but the present invention is not limited thereto. The present invention can also be applied to the case where the storage container after taking out the stored sulfide compound is reused (reproduced). That is, the sulfide-based compound is stored in the storage container manufactured as described above, and the storage container after the stored sulfide-based compound is taken out is subjected to a washing process and a drying process, thereby providing a new It can also be manufactured as a safe storage container. In this case, if the stored sulfide-based compound remains in the storage container, hydrogen sulfide may be generated when washing with pure water, so prior to washing with pure water. It is preferable to wash with an appropriate organic solvent.

  Further, by applying the present invention, the storage container can be processed into a state suitable for storing the sulfide-based compound. In this case, the storage container may be an unused container or a container after taking out the stored sulfide compound. Such a processing method is a method for processing a storage container for storing a sulfide-based compound into a state suitable for storage of the sulfide-based compound, the storage container including an inlet and an outlet. A step of preparing a container, a step of washing the interior of the storage container with pure water, a dry gas flowing out from the outlet and flowing out from the outlet while allowing dry gas to flow into the container from the inlet However, it can be set as the processing method of the sulfide type compound storage container including the process of drying the inside of the said storage container until it becomes below a dew point-30 degreeC.

  As described above, the present invention can be used as a technique for manufacturing a storage container for storing a sulfide-based compound so that no moisture remains in the container.

Claims (1)

In producing a storage container for storing sulfide compounds,
Forming the storage container having an inlet and an outlet into a predetermined form;
Washing the inside of the storage container with pure water;
A step of allowing the dry gas to flow out from the outlet while allowing the dry gas to flow into the container from the inlet, and drying the inside of the storage container until the dry gas flowing out from the outlet becomes a dew point of −30 ° C. or lower. ,
A process for producing a sulfide-based compound storage container, comprising: