JP6181988B2 - Manufacturing method of all solid state battery - Google Patents

Description

  The present invention relates to a method for manufacturing an all-solid battery.

In recent years, various electric vehicles are expected to be widely used for solving environmental and energy problems. As an in-vehicle power source such as a motor driving power source that holds the key to practical use of these electric vehicles, a lithium ion battery has been intensively developed.
A normal lithium ion battery has a safety problem because the electrolyte is an electrolyte. In order to ensure safety, all-solid-state batteries in which the electrolyte is an inorganic solid electrolyte are expected to be put into practical use.

As a method for producing an all-solid-state battery, a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are respectively formed by compressing and molding an electrode active material powder and / or a solid electrolyte powder into a mold, and integrating them. It has been known. Patent Document 1 discloses a method for manufacturing an all-solid battery in which an electrode mixture powder serving as a bonding layer is inserted between an electrode layer and a solid electrolyte layer, and the interface is bonded.
However, in the above powder molding, when the thickness of the whole laminate is large, there is a problem that when compressing with a press machine or the like, the strain in the surface direction is large and it is difficult to consolidate each layer and join the layer interface. In particular, in a stack cell (multilayered) in which dozens of electrode layers, solid electrolyte layers, and current collectors are stacked, interfacial bonding by consolidation is difficult.

JP 2001-293928 A

  An object of the present invention is to provide a method for producing an all-solid battery that does not require strong pressurization.

According to one aspect of the present invention, the following method for producing an all-solid battery is provided.
Producing a first member including a first electrode layer and a first solid electrolyte layer, wherein the first solid electrolyte layer is a surface layer, and a second member including a second electrode layer;
A step of applying a solvent to the surface of the first solid electrolyte layer, and a step of bonding the first member and the second member together on the surface of the first solid electrolyte layer coated with the solvent. A method for producing a solid state battery.

According to one aspect of the present invention, the following method for producing an all-solid battery is provided.
A first member comprising an electrode mixture comprising a solid electrolyte and an active material, wherein the first member is a surface layer, and the second member comprises a second electrode layer. Manufacturing process,
An all-solid battery comprising a step of applying a solvent to a surface of the first electrode layer, and a step of bonding the first member and the second member on a surface of the first electrode layer coated with the solvent Manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the all-solid-state battery which does not require strong pressurization can be provided.

It is a figure which shows an example of the manufacturing method of the 1st all-solid-state battery which concerns on one form of this invention. It is a figure which shows an example of the manufacturing method of the 1st all-solid-state battery which concerns on one form of this invention. It is a figure which shows an example of the manufacturing method of the 2nd all-solid-state battery which concerns on one form of this invention. It is a figure which shows an example of the manufacturing apparatus which can be used when manufacturing a solid electrolyte by a slurry synthesis method.

The manufacturing method of the 1st all-solid-state battery which concerns on one form of this invention includes the process of following (1-1)-(1-3):
(1-1) A first member including a first electrode layer and a first solid electrolyte layer, wherein the first solid electrolyte layer is a surface layer, and a second member including a second electrode layer, respectively Step of manufacturing (1-2) Step of applying solvent to surface of first solid electrolyte layer (1-3) Surface of first member and second member coated with solvent of first solid electrolyte layer The process of pasting together

In the first all-solid battery manufacturing method according to one aspect of the present invention, the first member and the second member are separately manufactured, and the all-solid battery is manufactured by bonding them together. Does not require pressure.
Strong pressurization causes distortion of the all-solid-state battery and causes performance degradation. However, in the method for manufacturing an all-solid-state battery according to one embodiment of the present invention, strong pressurization is not required, and thus the performance of the obtained battery is Decline can be prevented.

In the first all-solid battery manufacturing method according to one aspect of the present invention, the second member preferably includes a second solid electrolyte layer as a surface layer, and the following (1-1 ′) to (1-3) Including the process of '):
(1-1 ′) a first member including a first electrode layer and a first solid electrolyte layer, the first solid electrolyte layer being a surface layer, and a second electrode layer and a second solid electrolyte layer Step (1-2 ′) in which each of the second solid electrolyte layers is a surface layer, and the surface of the first solid electrolyte layer and the surface of the second solid electrolyte layer are each a solvent. (1-3 ′) A step of bonding the first member and the second member on the surface of the first solid electrolyte layer coated with the solvent and the surface of the second solid electrolyte layer coated with the solvent

1 and 2 are diagrams showing an example of a first all-solid-state battery manufacturing method (hereinafter sometimes simply referred to as a first manufacturing method) according to an embodiment of the present invention.
In FIG. 1, a first member 100 is a stacked body in which a current collector 130, a first electrode layer 110, and a first solid electrolyte layer 120 are stacked in this order, and a second member 200 includes a current collector 230 and The second electrode layer 210 is a laminated body laminated in this order. The first member 100 and the second member 200 are bonded to each other by bonding the first solid electrolyte layer 120 and the second electrode layer 210 in which a part of the surface is dissolved by a solvent.
In addition, when the 2nd electrode layer 210 contains the electrode compound material which consists of a solid electrolyte and an active material, you may apply | coat a solvent also to the said 2nd electrode layer 210, and may dissolve a part of surface.

In FIG. 2, the first member 100 is a stacked body in which a current collector 130, a first electrode layer 110, and a first solid electrolyte layer 120 are stacked in this order, and the second member 200 includes a current collector 230, This is a laminate in which the second electrode layer 210 and the second solid electrolyte layer are laminated in this order. The first member 100 and the second member 200 are bonded by bonding the first solid electrolyte layer 120 and the second solid electrolyte layer 220 together.
In FIG. 2, the surface is dissolved by the solvent in either one of the first solid electrolyte layer 120 and the second solid electrolyte layer 220, or the first solid electrolyte layer 120 and the second solid electrolyte layer 220. Preferably, both the first solid electrolyte layer 120 and the second solid electrolyte layer 220 are used.

The manufacturing method of the 2nd all-solid-state battery which concerns on one form of this invention includes the process of the following (2-1)-(2-3):
(2-1) a first member including an electrode mixture composed of a solid electrolyte and an active material, wherein the first member is a surface layer, and the second member includes a second electrode layer. (2-2) Applying a solvent to the surface of the first electrode layer (2-3) Applying the solvent of the first electrode layer to the first member and the second member The process of bonding on the finished surface

In the second all-solid-state battery manufacturing method according to one embodiment of the present invention (hereinafter sometimes simply referred to as a second manufacturing method), the first electrode layer of the first member includes an electrode mixture.
Also in the first manufacturing method, the first electrode layer of the first member may include an electrode mixture.

The second manufacturing method is the same as the first manufacturing method, and the first member and the second member are separately manufactured, and an all solid state battery is manufactured by bonding them together. And not.
Although strong pressurization causes distortion of the all-solid-state battery and causes performance deterioration, the second all-solid-state battery manufacturing method according to one embodiment of the present invention does not require strong pressurization, and thus is obtained. Battery performance degradation can be prevented.

In the second manufacturing method, the first electrode layer including the electrode mixture composed of the solid electrolyte and the active material may be either a positive electrode layer or a negative electrode layer.
Therefore, when the first electrode layer is a positive electrode layer, the electrode mixture included in the first electrode layer is a positive electrode mixture made of a solid electrolyte and a positive electrode active material. Similarly, when the first electrode layer is a negative electrode layer, the electrode mixture included in the first electrode layer is a negative electrode mixture made of a solid electrolyte and a negative electrode active material.

FIG. 3 is a diagram illustrating an example of a second all-solid battery manufacturing method according to an embodiment of the invention.
In FIG. 3, the first member 100 is a stacked body in which a current collector 130 and a first electrode layer 110 are stacked in this order, and the second member 200 includes a current collector 230, a second electrode layer 210, and a first electrode layer 110. The two solid electrolyte layers 220 are stacked in this order. The first member 100 and the second member 200 are bonded to each other by bonding the second solid electrolyte layer 220 and the first electrode layer 110 having a part of the surface dissolved by a solvent.
Note that a solvent may or may not be applied to the second solid electrolyte layer 220. Preferably, a solvent is also applied to the second solid electrolyte layer 220 to dissolve a part of the surface.

  Hereinafter, each process of the manufacturing method of the 1st and 2nd all-solid-state battery which concerns on one form of this invention is demonstrated.

[Process for producing first member and second member]
In the first manufacturing method, the first member is a laminate including a first electrode layer and a first solid electrolyte layer. Similarly, the second member is a laminate including a second electrode layer, preferably further including a second solid electrolyte layer.
In the second manufacturing method, the first member includes a first electrode layer including an electrode mixture made of a solid electrolyte and an active material, and the second member includes a second electrode layer.
In the above, the first electrode layer is either the positive electrode layer or the negative electrode layer, and the second electrode layer is the other of the positive electrode layer or the negative electrode layer. Therefore, if the first electrode layer is a positive electrode layer, the second electrode layer is a negative electrode layer, and if the first electrode layer is a negative electrode layer, the second electrode layer is a positive electrode layer.
Moreover, the first member and the second member may each further include a current collector, for example.
Hereinafter, each layer will be described.

(1) Positive electrode layer A positive electrode layer is a layer containing a positive electrode active material.
The positive electrode active material is a material capable of inserting and removing lithium ions, and those known as a positive electrode active material in the battery field can be used.
Examples of the positive electrode active material include V ₂ O ₅ , LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , Li (Ni _a Co _b Mn _c ) O ₂ (where 0 <a <1, 0 <b <1, 0 <c <1, a + b + c = 1), LiNi _1-Y Co _{Y 2} O ₂ , LiCo _1-Y Mn _{Y 2} O ₂ , LiNi _1-Y Mn _{Y 2} O ₂ (where 0 ≦ Y <1) _{, Li (Ni a Co b Mn} c) O 4 (0 <a <2,0 <b <2,0 <c <2, a + b + c = 2), LiMn 2-Z Ni Z O 4, LiMn 2-Z Co _Z O ₄ (where 0 <Z <2), LiCoPO ₄ , and LiFePO ₄ may be mentioned.
In the sulfide-based positive electrode active material, titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), iron sulfide (FeS, FeS ₂ ), copper sulfide (CuS), nickel sulfide (Ni ₃ S ₂ ), etc. can be used. TiS ₂ is preferable.
In the oxide-based positive electrode active material, bismuth oxide (Bi ₂ O ₃ ), bismuth leadate (Bi ₂ Pb ₂ O ₅ ), copper oxide (CuO), vanadium oxide (V ₆ O ₁₃ ), lithium cobalt oxide (LiCoO ₂₎ ), Lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), and the like. It is also possible to use a mixture of these. Preferably, lithium cobaltate can be used.
In addition, Li _x CoO ₂ , Li _x NiO ₂ , Li _x Mn ₂ O ₄ , Li _x FePO ₄ , LixCoPO ₄ , Li _x Mn _1/3 Ni _1/3 Co _1/3 O ₂ , Li _x Mn _1.5 Ni _0.5 O ₂ or the like can also be used (X is 0.1 to 0.9).

（式（Ａ）〜（Ｃ）において、Ｘはそれぞれ置換基であり、ｎ及びｍはそれぞれ独立に１〜２の整数であり、ｐ及びｑはそれぞれ独立に１〜４の整数である。
式（Ｄ）において、Ｚはそれぞれ−Ｓ−又は−ＮＨ−であり、ｎは繰返数２〜３００の整数である。）

（式中、ｎ、ｍは、それぞれ１以上の整数である。） In addition to the above, niobium selenide (NbSe ₃ ), organic disulfide compounds shown below, carbon sulfide compounds shown below, sulfur, lithium sulfide, indium metal, and the like can be used as the positive electrode active material.

(In Formulas (A) to (C), X is a substituent, n and m are each independently an integer of 1 to 2, and p and q are each independently an integer of 1 to 4.
In formula (D), Z is -S- or -NH-, respectively, and n is an integer of 2 to 300 repetitions. )

(In the formula, n and m are each an integer of 1 or more.)

The positive electrode layer may further contain a solid electrolyte and / or a conductive additive. When the first electrode of the second production method is a positive electrode layer, the positive electrode layer contains a solid electrolyte.
Examples of the solid electrolyte include those similar to the solid electrolyte included in the solid electrolyte layer described later.
The conductive auxiliary agent only needs to have conductivity, and its electronic conductivity is preferably 1 × 10 ³ S / cm or more, more preferably 1 × 10 ⁵ S / cm or more. Examples of the conductive aid include substances selected from carbon materials, metal powders and metal compounds, and mixtures thereof.

  Specific examples of conductive aids are preferably carbon materials, nickel, copper, aluminum, indium, silver, cobalt, magnesium, lithium, chromium, gold, ruthenium, platinum, beryllium, iridium, molybdenum, niobium, osnium, rhodium, A substance containing at least one element selected from the group consisting of tungsten and zinc, and more preferably a carbon simple substance having a high conductivity, or a carbon material other than simple carbon; nickel, copper, silver, cobalt, magnesium, lithium, ruthenium , Gold, platinum, niobium, osnium or rhodium, simple metals, mixtures or compounds.

  Specific examples of carbon materials include carbon blacks such as ketjen black, acetylene black, denka black, thermal black, and channel black; graphite, carbon fiber, activated carbon, and the like. These may be used alone or in combination of two or more. Is possible. Among these, acetylene black, denka black, and ketjen black having high electron conductivity are preferable.

The positive electrode layer may contain a binder in addition to the above components. Examples of binders include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), fluorine-containing resins such as fluororubber; thermoplastic resins such as polypropylene and polyethylene; ethylene-propylene-dienemer (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 dispersion of cellulose or styrene butadiene rubber (SBR), which is an aqueous binder, can also be used.

  The thickness of the positive electrode is preferably 0.01 mm or more and 10 mm or less.

(2) Negative electrode layer The negative electrode layer is a layer containing a negative electrode active material.
As the negative electrode active material, a material capable of inserting and desorbing lithium ions, and a material known as a negative electrode active material in the battery field can be used.
For example, carbon materials, specifically 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 Examples thereof include fibers, vapor-grown carbon fibers, natural graphite, and non-graphitizable carbon. Or it may be a mixture thereof. Preferably, it is artificial graphite.
An alloy combined with a metal itself such as metallic lithium, metallic indium, metallic aluminum, metallic silicon, or another element or compound can be used as the negative electrode material.

The negative electrode layer may contain a solid electrolyte, a conductive additive and / or a binder as other components. When the first electrode of the second production method is a negative electrode layer, the negative electrode layer contains a solid electrolyte. . As the solid electrolyte, the conductive assistant and the binder, the same ones as described above can be used.
The thickness of the negative electrode layer is preferably 0.01 mm or more and 10 mm or less.

(3) Solid electrolyte layer A solid electrolyte layer is a layer containing a solid electrolyte.
Examples of the solid electrolyte constituting the solid electrolyte layer include sulfide-based solid electrolytes and polymer-based solid electrolytes.
As the polymer solid electrolyte, as disclosed in, for example, JP-A-2010-262860, it is used as a polymer electrolyte such as fluororesin, polyethylene oxide, polyacrylonitrile, polyacrylate, and derivatives and copolymers thereof. Materials that can be used.

  Examples of the fluororesin that is a polymer-based solid electrolyte include a polymer containing, as a structural unit, vinylidene fluoride (VdF), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), or a derivative thereof. Specifically, homopolymers such as polyvinylidene fluoride (PVdF), polyhexafluoropropylene (PHFP), polytetrafluoroethylene (PTFE); a copolymer of VdF and HFP (hereinafter, this copolymer is referred to as “P (VdF-HFP) ") and the like, and binary copolymers and ternary copolymers.

  The solid electrolyte contained in the solid electrolyte layer is preferably a sulfide-based solid electrolyte, more preferably a lithium ion conductive inorganic solid electrolyte (sulfide-based solid electrolyte) containing Li, P and S, and more preferably Li , P, S, and halogen element-containing lithium ion conductive inorganic solid electrolyte (sulfide-based solid electrolyte).

The sulfide-based solid electrolyte containing Li, P, S and a halogen element is preferably a sulfide-based solid electrolyte having a composition represented by the following formula (1).
_{L a M b P c S d} X e O f ... (1)
(In the formula, L represents an alkali metal.
M represents B, Al, Si, Ge, As, Se, Sn, Sb, Te, Pb, Bi, or a combination thereof.
X represents I, Cl, Br, F, or a combination thereof.
a to f satisfy 0 <a ≦ 12, 0 ≦ b ≦ 0.2, c = 1, 0 <d ≦ 9, 0 <e ≦ 9, and 0 ≦ f ≦ 9, respectively. )

In the formula (1), a to f indicate the composition ratio of each element, and 0 <a ≦ 12, 0 ≦ b ≦ 0.2, c = 1, 0 <d ≦ 9, 0 <e ≦ 9, 0 ≦ f ≦ 9 is satisfied.
In the formula (1), preferably, b is 0, and more preferably, the ratio of a, c, d, e and f (a: c: d: e: f) is a: c: d: e: f = 1 to 9: 1: 3 to 7: 0.05 to 3: 0 to 2, more preferably, a: c: d: e: f = 2 to 6.5: 1: 3.5 to 5: It is 0.1-1.5: 0-1. Most preferably, a: c: d: e: f = 2 to 6.5: 1: 3.5 to 4.95: 0.1 to 1.5: 0 to 0.5. d is preferably 4.
When f is not 0, it is desirable to add so that d + f = 4.
The composition ratio of each element can be controlled by adjusting the compounding amount of the raw material compound when producing the solid electrolyte or the solid electrolyte precursor (solid electrolyte glass).

The solid electrolyte having the composition represented by the formula (1) is preferably a solid electrolyte 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 B, Al, Si, Ge, As, Se, Sn, Sb, Te, Pb, Bi, or a combination thereof.
X represents I, Cl, Br, F, or a combination thereof.
a to e satisfy 0 <a ≦ 12, 0 ≦ b ≦ 0.2, c = 1, 0 <d ≦ 9, and 0 <e ≦ 9, respectively. )

In the formula (1 ′), a to e each indicate a composition ratio of each element, and 0 <a ≦ 12, 0 ≦ b ≦ 0.2, c = 1, 0 <d ≦ 9, and 0 <e ≦ 9. Fulfill.
Preferably, b is 0, and more preferably, the ratio of a, c, d, e (a: c: d: e) is a: c: d: e = 1-9: 1: 3-7: It is 0.05-3, More preferably, it is a: c: d: e = 2-6.5: 1: 3.5-5: 0.1-1.5. Most preferably, a: c: d: e = 2 to 6.5: 1: 3.5 to 4.95: 0.1 to 1.5.
d is preferably 4.

_{L a M b P c S d} X e O f and _{L a M b P c S d} X e each element constituting the solid electrolyte represented by is preferably as follows:
The alkali metal of L includes one or more selected from Li, Na, K, Rb, Ce and Fr, preferably one or more selected from Li and Na, and more preferably Li.
M is preferably B, Al, Si, or a combination thereof.
X is preferably I, Br or Cl, more preferably Br.

The solid electrolyte constituting the solid electrolyte layer can be prepared, for example, by using the following components (A), (B), and (C).
(A) an alkali metal sulfide (B) M _'m S _n compound represented by _{(C) M''w X} x compound represented by (wherein, M' is, Li, Na, B, Al , Si , P, Ge, or a combination thereof.
M ″ represents Li, Na, B, Al, Si, P, S, Ge, As, Se, Sn, Sb, Te, Pb, Bi, or a combination thereof.
X represents F, Cl, Br, I, or a combination thereof.
w represents an integer of 1 or 2.
m, n and x each represent an integer of 1 to 10. )

The (A) alkali metal sulfide, _Li 2 S (lithium sulfide), _Na 2 S (sodium sulfide) and the like, preferably lithium sulfide.
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, JP-A-2011-84438, and JP-A-2011-136899.

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). Open 2011-84438).

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.

(B) Examples of the compound represented by _{M 'm S n, P 2} S 3 ( trisulfide _{diphosphorus),} P 2 _{S 5} (phosphorus pentasulfide), SiS ₂ (sulfide _silicon), Al _{2 S} 3 ( Aluminum sulfide), GeS ₂ (germanium sulfide), B ₂ S ₃ (diarsenic trisulfide), Na ₂ S (sodium sulfide) and the like can be mentioned, and P ₂ S ₅ is preferable.
As long as diphosphorus pentasulfide (P ₂ S ₅ ) is industrially manufactured and sold, it can be used without particular limitation.

(C) The compound represented by M ″ _w X _x is preferably a compound in which M ″ is lithium or phosphorus.
Specifically, the compound represented by (C) M ″ _w X _x which is a compound containing a halogen element includes 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 _{, 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 , NaI, NaF, NaCl, NaBr and the like, preferably LiCl, LiBr, LiI, PCl ₅ , PCl ₃ , PBr ₅ and PBr ₃ , more preferably LiCl. , LiBr, is LiI and PBr _3.
In place of the component (C), an oxide of a compound represented by the formula (C) such as POCl ₃ or POBr ₃ can also be used.

  The solid electrolyte having the composition represented by the formula (1) is a compound of the formula (1) containing an oxygen element by using a vitrification accelerator described later, even if the component (C) is a compound not containing an oxygen element. Can be produced.

The mixing ratio of the components (A), (B), and (C) depends on whether M ″ of the component (C) is phosphorus or other than phosphorus.
(I) 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 to 83:17 (molar ratio), more preferably (A) :( B) = 67: 33 to 80:20 (molar ratio), most preferably (A) :( B) = 72: 28-78: 22 (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).
(Ii) 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 the component (A) is lithium sulfide. And 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.

In addition to the component (A), the component (B) and the component (C) which is a compound containing a halogen element, a compound (vitrification accelerator) for reducing the glass transition temperature may be added. 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 .

A glassy solid electrolyte can be produced by the following method using the components (A) to (C) and optionally a vitrification accelerator.
Raw materials (for example, sodium sulfide, diphosphorus pentasulfide, and halogen compounds) are mixed in the above-mentioned mixing ratio, and melt-quenched method, mechanical milling method (hereinafter, “mechanical milling” is appropriately referred to as “MM”), and in a solvent. A glassy solid electrolyte can be produced by treatment by any of a slurry method, a solid phase method, and the like.
Hereinafter, each manufacturing method will be described.

(I) Melting and quenching method The melting and quenching method is a method of obtaining a glassy solid electrolyte 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 making it react at a predetermined reaction temperature, it is put into ice and rapidly cooled to obtain a glassy solid electrolyte.
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 glassy solid electrolyte 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, by mixing a predetermined amount of diphosphorus pentasulfide (P2S5), lithium sulfide (Li2S) and a halogen compound in a mortar and reacting them for a predetermined time using, for example, various ball mills, a glassy solid electrolyte is obtained. It is done.
The MM method using the above raw materials can be reacted at room temperature. Therefore, there is an advantage that a glassy solid electrolyte having a charged composition can be obtained without thermal decomposition of the raw material.
Further, the MM method has an advantage that it can be finely powdered simultaneously with the production of the glassy solid electrolyte.

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.
The raw material temperature during MM treatment may be heated from room temperature to 200 ° C. as necessary.

(Iii) Solid phase method The solid phase method is a method of obtaining a glassy solid electrolyte by mixing raw materials and heating at a predetermined temperature. For example, by mixing a predetermined amount of diphosphorus pentasulfide (P ₂ S ₅ ), lithium sulfide (Li ₂ S), and a halogen compound in a mortar and heating at a temperature of 100 to 900 ° C., a glassy solid electrolyte is obtained. Is obtained.

(Iv) Contact Method The contact method is a method for producing a glassy solid electrolyte by contacting a raw material in a solvent.
According to the contact method, a glassy solid electrolyte 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 disadvantage that raw materials and solid electrolytes adhere to the balls and the mill vessel.

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 Halogenated hydrocarbons such as fluorinated compounds such as benzene, 2,3-dihydroperfluoropentane, 1,1,2,2,3,3,4-heptafluorocyclopentane, and the like.

As said alcohol, the monovalent | monohydric alcohol solvent of a following formula is mentioned, for example.
R ¹ —OH
(R ¹ is a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group, or a cyclic aliphatic hydrocarbon group, preferably a linear aliphatic hydrocarbon group.
The linear aliphatic hydrocarbon group has preferably 1 or more and less than 20 carbon atoms, and more preferably 1 or more and 8 or less. The number of carbon atoms of the branched aliphatic hydrocarbon group is preferably 3 or more and less than 20, and more preferably 3 or more and 8 or less. The number of carbon atoms of the cycloaliphatic hydrocarbon group is preferably 3 or more and less than 20, and more preferably 5 or more and 8 or less. )

  If the solvent used by the above-mentioned contact method is a solvent which can melt | dissolve the solid electrolyte to be used, it can be similarly used for the solvent used by the manufacturing method mentioned 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 made at 100 ° C. for 1 hour from the start of contact, and heating 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 glassy solid electrolyte. 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 a glassy solid electrolyte having excellent uniformity and 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 per liter of solvent is 0.01 kg or more and 1 kg or less. 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 wet 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 wet mechanical milling process are not particularly limited, but the higher the rotation speed, the faster the production rate of the glassy solid electrolyte, and the longer the rotation time, the conversion rate of the raw material to the glassy solid electrolyte Becomes higher. 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 a glassy electrolyte.
The balls of the ball mill may be used by mixing balls having different diameters.
In addition to the above, the temperature in the mill during MM processing may be adjusted. 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.

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.
The resulting product after the mechanical milling treatment is dried and the solvent is removed to obtain a glassy solid electrolyte.

(Vi) Slurry synthesis method The slurry synthesis 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 glassy solid electrolyte using a manufacturing apparatus comprising: a connecting means for connecting the two materials; and a circulating means for circulating the raw material and / or a reactant of the raw material between the mechanical energy supplying means and the contacting means through the connecting means It is a method of manufacturing. By drying the reaction product and removing the solvent, a glassy solid electrolyte is obtained.
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 slurry synthesis method, the reaction is performed with a 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, it is possible to obtain a glassy solid electrolyte having excellent uniformity and 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, thereby improving the product yield.

FIG. 4 is a diagram illustrating an example of a manufacturing apparatus that can be used in the slurry synthesis method.
The manufacturing apparatus 1 includes a pulverizer (crushing and synthesizing means) 10 that synthesizes a glassy solid electrolyte by reacting while pulverizing raw materials, and a reaction tank (synthesizing means) that synthesizes the glassy solid electrolyte by reacting the raw materials. 20. 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 glassy 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 glassy solid electrolyte. While maintaining the temperature in the reaction tank 20 by the oil bath 40, the raw materials are reacted in a solvent to synthesize a glassy 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 synthesizing the glassy solid electrolyte in the pulverizer 10 and the reaction vessel 20, the raw material being reacted is circulated between the pulverizer 10 and the reaction vessel 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.

  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 manufacture of a glassy solid electrolyte 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 process are not particularly limited, but the faster the rotation speed, the faster the glassy solid electrolyte production rate, and the longer the rotation time, the conversion rate of the raw material to the glassy solid electrolyte is Get higher. 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 during which the raw material and the glassy solid electrolyte remain in the planetary ball mill. Accordingly, the raw material and the glassy solid electrolyte circulate through the planetary ball mill and the reaction vessel, but the total time that the raw material and the glassy solid 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, the amount of raw materials and glassy solid electrolyte that can be stored at one time is increased, or the following reaction is completed. There is a possibility that a problem that the time until the time becomes longer may occur.

About a contact process, the contact means illustrated by the slurry synthesis 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 a slurry synthesis 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 solid electrolyte remain in the reaction tank. Accordingly, the raw material and the glassy solid electrolyte circulate in the planetary ball mill and the reaction tank, but the total time that the raw material and the glassy solid 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 the glassy solid electrolyte 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, Final glassy solid The composition of the electrolyte may be in a range that satisfies the above formula (1).

The volume-based average particle diameter (Mean Volume Diameter, hereinafter referred to as “particle diameter”) of the obtained solid electrolyte (glass) is preferably 0.01 μm or more and 500 μm or less.
The particle size 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.

As a measurement example, measurement when a laser diffraction particle size distribution measuring apparatus (Mastersizer 2000 manufactured by Malvern Instruments Ltd.) is used will be described.
First, 110 ml of dehydrated toluene (manufactured by Wako Pure Chemicals, product name: special grade) is placed in a dispersion tank of the apparatus, and 6% of the dehydrated dispersant is further added as a dispersant.
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.

In the solid electrolyte (glass), two exothermic peaks (crystallization peaks) are preferably observed by the following measurement method, more preferably the two crystallization peaks are in the range of 150 ° C. or higher and 360 ° C. or lower. It is preferable that the width between two crystallization peaks is 20 to 150 ° C, preferably 20 to 100 ° C.
The crystallization temperature (peak) was measured by using a differential thermo-thermogravimetric apparatus (TGA / DSC1 manufactured by METTLER TOLEDO) or a differential scanning calorimeter (Diamond DSC manufactured by PerkinElmer Co.). It can be identified by measuring in minutes.
The solid electrolyte (glass) has two crystallization peaks, the two crystallization peaks are in the range of 170 ° C. or higher and 330 ° C. or lower, and the width between the two crystallization peaks is 20 to 150 ° C. More preferably.
The two crystallization peaks are more preferably in the range of 170 ° C. or higher and 330 ° C. or lower, and the width between the two crystallization peaks is more preferably 30 to 140 ° C.
The solid electrolyte (glass) has two crystallization peaks, the two crystallization peaks are in the range of 175 ° C. or more and 320 ° C. or less, and the width between the two crystallization peaks is 30 to 140 ° C. It is particularly preferred.
The two crystallization peaks are particularly preferably in the range of 175 ° C. or more and 320 ° C. or less, and the width between the two crystallization peaks is particularly preferably 35 to 130 ° C. The solid electrolyte has two crystallization peaks, the two crystallization peaks are in the range of 180 ° C. or more and 310 ° C. or less, and the width between the two crystallization peaks is most preferably 40 to 120 ° C. preferable.

  Crystallization of the solid electrolyte powder glass of the present invention can be obtained by heat-treating the glassy solid electrolyte.

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. If the heating temperature is lower than the 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 peaks by thermophysical property measurement, the temperature of the first crystallization peak on the low temperature side is Tc1, the temperature of the Tc1 on the low temperature side and the temperature of the second crystallization peak on the high temperature side (Tc2) It is preferable to heat at a temperature not lower than the first crystallization temperature and not higher than the second crystallization temperature.
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 glassy solid electrolyte can be specified by differential thermo-thermogravimetry or the like. For example, a thermogravimetry apparatus (TGA / DSC1 manufactured by METTLER TOLEDO) is used, and the glassy solid electrolyte is about 20 mg. Can be identified by measuring by heating at a heating rate of 10 ° C./min.
It should be noted that the crystallization temperature or the like may change depending on the temperature rising rate or the like, and should be selected based on Tc measured at a rate close to the temperature rising rate for heat treatment. Therefore, when the treatment is performed at a temperature raising rate other than the example, the optimum heat treatment temperature changes, but it is desirable to perform the heat treatment under the above-mentioned conditions with reference to Tc measured at the temperature raising 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.
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 electrolyte layer may consist only of a solid electrolyte, and may further contain a binder. As the binder, the same binders as described above can be used.

The thickness of the electrolyte layer is preferably 0.001 mm or more and 1 mm or less.
The solid electrolyte of the electrolyte layer is preferably fused. Fusion means that a part of the solid electrolyte particles is dissolved and the dissolved part is integrated with other solid electrolyte particles. The electrolyte layer may be a solid electrolyte plate, and the plate includes a case where a part or all of the solid electrolyte particles are dissolved to form a plate.

(4) Current collector Each of the first laminate and the second laminate may further include a current collector, and a known current collector can be used as the current collector.
The current collector is a layer in which a layer made of a metal that reacts with a sulfide-based solid electrolyte, such as Au, Pt, Al, or Cu, is further coated with Au, conductive carbon, or the like.

The formation method of the 1st laminated body and 2nd laminated body of an all-solid-state battery can be manufactured by a well-known method using the above-mentioned material, for example, the coating method, the electrostatic method aerosol deposition method, a screen It can be produced by a printing method, a cold spray method or the like.
The first laminated body and the second laminated body are preferably consolidated in advance before being attached to each other. For consolidation, for example, a roll press or a surface press can be used, and heating may be performed at that time.

[Step of applying a solvent to the surface of the solid electrolyte layer or the electrode layer]
The solvent applied to the first solid electrolyte layer or the first electrode layer that is the surface layer of the first member is a solid electrolyte that forms the first solid electrolyte layer, or an electrode that forms the first electrode layer. The solvent is not particularly limited as long as it can dissolve the solid electrolyte of the composite material. The same applies to the case where the second member includes the second solid electrolyte layer.

For example, when the first solid electrolyte layer and the second solid electrolyte layer of the first production method and the first electrode layer of the second production method each contain a sulfide-based solid electrolyte, they are used for surface coating. The solvent to be used is preferably a solvent of a compound having a hydroxyl group, more preferably a monovalent alcohol solvent, and still more preferably a solvent represented by the following formula.
R ² —OH
(In the formula, R ² is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. Other than ester groups, ether groups, hydroxyl groups, nitrile groups, halogen groups such as fluorine, bromine, chlorine, etc.) Or a cyclic group such as an aromatic ring, which may be branched or unbranched)
R ² is preferably an alkyl group having 2 to 20 carbon atoms, more preferably an alkyl group having 2 to 12 carbon atoms, which may have other substituents, and is alicyclic. It may be branched or not branched.

In the monovalent alcohol solvent, R ² is preferably an alkyl group having 2 to 10 carbon atoms, has no other substituent, may be alicyclic, and is branched or not branched. May be. A primary or secondary alcohol is preferred. Specifically, for example, one or more alcohol solvents selected from ethanol, isopropanol, 1-butanol, 2 ethylhexanol, and 1-octanol are preferable.

By using the above-mentioned solvent, the amount of the solvent used can be reduced, the efficiency of the drying process during film formation is increased, and the liquid viscosity can be easily adjusted.
The water in the solvent is preferably dehydrated to 50 ppm or less. More preferably, the moisture is 20 ppm or less.
The solvent may be a mixture of alcohols or a mixture of alcohols and other organic solvents.

The method of applying a solvent to the surfaces of the first solid electrolyte layer and the second solid electrolyte layer of the first production method, and the method of applying a solvent to the surface of the first electrode layer of the second production method are as follows: For example, a known coating method such as spray coating or a doctor blade can be employed, and these coating methods can be used to apply the solvent to the surface of the layer to be bonded. Moreover, it can apply | coat to the surface also by immersing and impregnating the surface part of the layer to bond together in the storage tank of the said solvent.
The application method is not particularly limited as long as it is a method for applying a surface, and the solvent may be heated to accelerate the dissolution speed.

The surface of the electrode layer or solid electrolyte layer is dissolved by applying a solvent to the surface of the solid electrolyte layer or electrode layer. Here, “dissolve the surface” means, for example, that only the surface layer of the electrode layer or the solid electrolyte layer is dissolved to the extent that bonding is possible.
Melting to such an extent that bonding is possible is not particularly limited as long as two members can be bonded, but is preferably within 10 microns from the surface of the electrode layer or solid electrolyte layer, and more preferably within 5 microns. If the electrode layer and the deep part of the solid electrolyte layer are dissolved and bonded together, it may be difficult to remove the solvent.

[Step of bonding first member and second member]
In the case of the first manufacturing method, the first member and the second member are preferably bonded together, for example, in a state where the surface of the first solid electrolyte layer is dissolved by a solvent or in a wet state. This is the same when the second laminate includes the second solid electrolyte layer. In the case of the second manufacturing method, the first electrode layer may be carried out in a state where the surface is dissolved by a solvent or in a wet state.

After bonding the first member and the second member, pressure may be applied using a press. The press machine that can be used is a cold / hot press machine, a cold / hot roll press machine, etc., and is not particularly limited.
Moreover, the removal of the solvent after bonding the first member and the second member may be performed by air drying or using a vacuum heating dryer. Further, the removal may be performed simultaneously with the above-described hot press. The boiling point is preferably equal to or higher than the boiling point of the solvent used, and is not particularly limited as long as it is equal to or lower than the thermal decomposition temperature of the constituent materials. For example, the range of 70 degreeC-350 degreeC and the range of 100 degreeC-300 degreeC are mentioned. In terms of solvent removal efficiency, it is more preferable to heat under reduced pressure.

Production Example 1
[Production of lithium sulfide (Li ₂ S)]
Production and purification of lithium sulfide were carried out in the same manner as in the examples of WO 2005/040039 pamphlet. Specifically, it is as follows.
(1) Production of lithium sulfide A 10-liter autoclave equipped with a stirring blade was charged with 3326.4 g (33.6 mol) of N-methyl-2-pyrrolidone (NMP) and 287.4 g (12 mol) of lithium hydroxide at 300 rpm. The temperature was raised to 130 ° C. After the temperature rise, hydrogen sulfide was blown into the liquid at a supply rate of 3 liters / minute for 2 hours.
Subsequently, this reaction solution was heated in a nitrogen stream (200 cc / min) to dehydrosulfide a part of the reacted hydrogen sulfide. As the temperature increased, water produced as a by-product due to the reaction between hydrogen sulfide and lithium hydroxide started to evaporate, but this water was condensed by the condenser and extracted out of the system. While water was distilled out of the system, the temperature of the reaction solution rose, but when the temperature reached 180 ° C., the temperature increase was stopped and the temperature was kept constant. After the dehydrosulfurization reaction was completed (about 80 minutes), the reaction was completed to obtain lithium sulfide.

(2) Purification of lithium sulfide After decanting NMP in the 500 mL slurry reaction solution (NMP-lithium sulfide slurry) obtained in (1) above, 100 mL of dehydrated NMP was added and stirred at 105 ° C. for about 1 hour. . NMP was decanted at that temperature. Further, 100 mL of NMP was added, stirred at 105 ° C. for about 1 hour, NMP was decanted at that temperature, and the same operation was repeated a total of 4 times. After completion of the decantation, lithium sulfide was dried at 230 ° C. (temperature higher than the boiling point of NMP) under a nitrogen stream for 3 hours under normal pressure. The impurity content in the obtained lithium sulfide was measured.
Incidentally, lithium sulfite _(Li 2 _SO 3), the content of each sulfur oxide lithium sulfate _(Li 2 SO ₄₎ and lithium thiosulfate _{(Li 2 S 2 O 3)} , and N- methylamino acid lithium (LMAB) Was quantified by ion chromatography. As a result, the total content of sulfur oxides was 0.13% by mass, and LMAB was 0.07% by mass.

Production Example 2
[Production of solid electrolyte 1]
Lithium sulfide (Li ₂ S) prepared in Production Example 1 and diphosphorus pentasulfide (P ₂ S ₅ ) (manufactured by Aldrich) were used as starting materials. 10 g of the mixture prepared in a molar ratio of 75:25 and 600 g of zirconia balls having a diameter of 10 mm were placed in a 500 mL alumina container, and mechanical milling was performed at 220 rpm for 20 hours with a planetary ball mill (LP-4 manufactured by Ito Seisakusho). By processing, a sulfide-based glass solid electrolyte (solid electrolyte 1) which was a white yellow powder was obtained.
As a result of putting the obtained solid electrolyte 1 into 1-butanol, it was confirmed that it was dissolved.

Production Example 3
[Production of solid electrolyte 2]
The lithium sulfide (Li ₂ S) prepared in Production Example 1, diphosphorus pentasulfide (P ₂ S ₅ ) (manufactured by Aldrich) and lithium bromide (LiBr) (manufactured by Aldrich) were used as starting materials. 10 g of a mixture prepared in a molar ratio of 77: 23: 17.3 (65.6 / 19.6 / 14.8) and 600 g of zirconia balls having a diameter of 10 mm were placed in a 500 mL alumina container, and a planetary ball mill ( A sulfide-based glass solid electrolyte (solid electrolyte 2), which is a white yellow powder, was obtained by mechanical milling at 220 rpm for 20 hours using LP-4 manufactured by Ito Seisakusho.
As a result of putting the obtained solid electrolyte 2 into 1-butanol, it was confirmed that it was dissolved.

Production Example 4
[Preparation of positive electrode paint]
LiNi _0.8 Co _0.15 Al _0.05 O ₂ (manufactured by Toda Kogyo Co., Ltd., NAT5050, average particle size: 5 μm) as a positive electrode active material in a container of a swirl type high-speed dispersion device filmics (30-25 type) 30 parts by mass of solid electrolyte 1 and 45 parts by mass of a polymer solution (resin concentration: 3.38 wt%) obtained by dissolving PVDF-HFP copolymer (manufactured by Kaynar, 2500) in isobutyronitrile, Dispersion was performed at a peripheral speed of 20 m / s for 30 seconds to obtain a positive electrode paint.

Production Example 5
[Preparation of negative electrode paint]
In a container of a swirl type high-speed dispersion device filmics (30-25 type), as a negative electrode active material, 60 parts by mass of graphite (manufactured by Nippon Graphite Co., Ltd., CGB20, average particle size: 20 μm), 40 parts by mass of solid electrolyte 1, PVDF -68.4 parts by mass of a polymer solution (resin concentration: 1.48 wt%) in which HFP copolymer (manufactured by Kaynar 2500) is dissolved in isobutyronitrile is added and dispersed at a peripheral speed of 20 m / s for 30 seconds. A negative electrode paint was obtained.

Production Example 6
[Preparation of solid electrolyte slurry]
40 parts by mass of solid electrolyte 2 and 60 parts by mass of toluene are put into a container of a planetary ball mill apparatus (Fritsch, P-7), zirconia balls having a diameter of 10 mm are placed, and dispersion treatment is performed at 350 rpm for 1 hour. A slurry was prepared.

Production Example 7
[Production of conductive coated current collector]
Using a doctor blade (application width: 150 mm, application thickness: 50 μm), an electrically conductive paint (made by Nippon Graphite Co., Ltd., trade name: Bunny Height UCC-2) is applied to an aluminum foil (width: 200 mm, thickness: 30 μm), The coating layer having a thickness of 5 μm was formed by drying under reduced pressure at 150 ° C. for 2 hours to obtain a conductive coated aluminum foil as a current collector.
Further, a conductive coated copper foil as a current collector was obtained in the same manner as above except that a copper foil (width: 200 mm, thickness: 30 μm) was used instead of the aluminum foil.

Production Example 8
[Formation of a laminate comprising a current collector, a positive electrode sheet and a solid electrolyte layer]
Using the doctor blade, the prepared positive electrode paint was applied onto the conductive coated aluminum foil and dried at 150 ° C. for 2 hours to obtain a positive electrode mixture sheet having a thickness of 95 μm.

A PET sheet (thickness: 200 μm) provided with an opening of 20 × 20 mm was placed on the manufactured positive electrode mixture sheet, and the prepared solid electrolyte slurry was poured, leveled with a squeegee spatula, and air-dried. Thereafter, the PET sheet was removed and dried under reduced pressure at 100 ° C. for 2 hours to prepare a two-layer sheet comprising a positive electrode sheet and a solid electrolyte layer.
After cutting out the portion (20 × 20 mm in size) where the solid electrolyte layer was formed, the two-layer sheet was consolidated at a pressure of 500 MPa using a hydraulic press to form a laminate composed of the positive electrode sheet and the solid electrolyte layer. did.

Production Example 9
[Formation of laminate comprising current collector, negative electrode sheet and solid electrolyte layer]
Using the doctor blade, the prepared negative electrode paint was applied onto the conductive coated copper foil sheet and dried at 150 ° C. for 2 hours to obtain a sheet coated with a 90 μm-thick negative electrode paint. Further, this sheet was cut into a size of 20 × 20 mm, and then consolidated with a pressure of 500 MPa using a hydraulic press machine to obtain a negative electrode mixture sheet.

A PET sheet (thickness: 200 μm) having an opening of 20 × 20 mm was placed on the manufactured negative electrode composite sheet, and the prepared solid electrolyte slurry was poured into it, leveled with a squeegee spatula, and air-dried. Thereafter, the PET sheet was removed, and after drying under reduced pressure at 100 ° C. for 2 hours, a two-layer sheet comprising a negative electrode layer and a solid electrolyte layer was produced.
After cutting out the portion (20 × 20 mm in size) where the solid electrolyte layer was formed, using a hydraulic press machine, the two-layer sheet was consolidated at a pressure of 500 MPa to form a laminate composed of the negative electrode sheet and the solid electrolyte layer. did.

Example 1
After applying 1-butanol to the surface of the solid electrolyte layer of the laminate composed of the positive electrode sheet and the solid electrolyte layer, and the surface of the negative electrode sheet not including the solid electrolyte layer using a spray gun, respectively, and dissolving the surface Then, the solid electrolyte layer and the negative electrode sheet were faced to each other and bonded together at a pressure of 10 MPa using a press, and dried at 150 ° C. under reduced pressure to produce a battery.

When an electrode tab was attached to each current collector of the obtained battery and sealed with an aluminum laminate film to form a battery cell, there was no internal short circuit. This battery cell was charged / discharged at 25 ° C. and a current density of 100 μA / cm ² , and the battery characteristics (initial charge / discharge efficiency) were examined. As a result, the initial charge / discharge efficiency was 85%.
The initial charge / discharge efficiency was calculated from the ratio of the capacity discharged thereafter, with the charged capacity (mAh / g) per gram of the positive electrode active material being 100%.

Example 2
Instead of the negative electrode sheet not forming the solid electrolyte layer, a laminate composed of the negative electrode sheet and the solid electrolyte layer was used, and 1-butanol was applied to the solid electrolyte layer of the laminate, as in Example 1. Battery cells were manufactured and evaluated.
The initial charge / discharge efficiency of the obtained battery cell was 70%.

Comparative Example 1
A laminated body composed of a positive electrode sheet and a solid electrolyte layer, and a negative electrode sheet not formed with a solid electrolyte layer were bonded together at a pressure of 10 MPa using a press to produce a lithium ion battery. An electrode tab was attached to each current collector of the obtained lithium ion battery and sealed with an aluminum laminate film to form a battery cell. When the charge / discharge characteristics were evaluated, it did not work.

A battery cell was produced and evaluated in the same manner as in Comparative Example 1 except that a laminate composed of a negative electrode sheet and a solid electrolyte layer was used instead of the negative electrode sheet on which the solid electrolyte layer was not formed.
However, the obtained battery cell did not operate as a battery.

DESCRIPTION OF SYMBOLS 10 Crusher 20 Reaction tank 22 Container 24 Stirring blade 26 Cooling pipe 30 Heater 40 Oil bath 50 Connecting pipe 52 Connecting pipe 54 Pump 60 Heat exchanger 100 1st member 110 1st electrode layer 120 1st solid electrolyte layer 130 Current collector 200 Second member 210 Second electrode layer 220 Second solid electrolyte layer 230 Current collector

Claims (11)

Producing a first member including a first electrode layer and a first solid electrolyte layer, wherein the first solid electrolyte layer is a surface layer, and a second member including a second electrode layer;
Applying the solvent for dissolving the solid electrolyte on the surface of the first solid electrolyte layer; and bonding the first member and the second member on the surface to which the solvent of the first solid electrolyte layer is applied. A method for producing an all-solid battery including a step of combining. The second member includes a second solid electrolyte layer as a surface layer;
Applying a solvent that dissolves the solid electrolyte on the surface of the second solid electrolyte layer; and applying the first member and the second member to the surface of the first solid electrolyte layer applied with the solvent; The manufacturing method of the all-solid-state battery of Claim 1 including the process of bonding on the surface which apply | coated the solvent of the 2nd solid electrolyte layer.   The manufacturing method of the all-solid-state battery of Claim 1 or 2 in which a said 1st solid electrolyte layer contains sulfide type solid electrolyte.   The manufacturing method of the all-solid-state battery of Claim 2 in which a said 2nd solid electrolyte layer contains sulfide type solid electrolyte. Includes a first electrode layer including the electrode composite comprising a solid electrolyte and the active material, the first member and the first electrode layer is the surface layer, and the second electrode layer and the second solid electrolyte layer unrealized, step the second solid electrolyte layer is produced respectively the second member is a surface layer,
Applying a solvent to dissolve the solid electrolyte to the surface of the first electrode layer process, and the first member and the second member, wherein the first solvent The coated surface of the electrode layer and the second The manufacturing method of the all-solid-state battery including the process bonded together on the surface of the solid electrolyte layer .   The method for producing an all-solid battery according to claim 5, wherein the solid electrolyte is a sulfide-based solid electrolyte.   The method for producing an all solid state battery according to claim 3, 4 or 6, wherein the sulfide solid electrolyte is a lithium ion conductive inorganic solid electrolyte containing Li, P and S.   The method for producing an all-solid-state battery according to claim 3, 4, 6, or 7, wherein the sulfide-based solid electrolyte is a lithium ion conductive inorganic solid electrolyte containing Li, P, S and a halogen element. The method for producing an all solid state battery according to any one of claims 3, 4, and 6 to 8 , wherein the solvent is an aprotic solvent. The method for producing an all solid state battery according to any one of claims 3, 4, and 6 to 8 , wherein the solvent is a monovalent alcohol. The all-solid-state battery according to claim 10, wherein the monovalent alcohol is an alcohol represented by the following formula.
R ² —OH
(In the formula, R ² is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms.)

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