JP2008124011A - Lithium ion conductive solid electrolyte sheet, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithium ion conductive solid electrolyte sheet having high ion conductivity, and to provide its manufacturing method. <P>SOLUTION: The manufacturing method of a crystalline lithium ion conductive solid electrolyte sheet is provided with a glass-like lithium ion conductive solid electrolyte to be formed in a sheet, then or at the same time, to be carried out thermal treatment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lithium ion conductive solid electrolyte sheet used for a solid secondary battery or the like and a method for producing the same.

In recent years, the demand for secondary batteries such as high-performance lithium batteries used in personal digital assistants, portable electronic devices, small household power storage devices, motorcycles powered by motors, electric vehicles, hybrid electric vehicles, etc. has increased. Yes.
As the applications used expand, further improvements in safety and higher performance of secondary batteries are required.
In order to ensure the safety of the lithium battery, it is effective to use an inorganic solid electrolyte instead of the organic solvent electrolyte.

  Inorganic solid electrolytes are generally nonflammable in nature and are safer materials than commonly used organic solvent electrolytes. Therefore, high performance of an all-solid lithium battery using the electrolyte is desired.

For example, Patent Document 1 discloses that a lithium ion conductive solid electrolyte containing a crystal component produced from lithium sulfide and diphosphorus pentasulfide exhibits high ionic conductivity.
WO2005 / 078740 pamphlet

However, in order to use such a crystalline solid electrolyte (powder) as a solid electrolyte layer in a battery, when the sheet is formed into a sheet or pellet, the molded product may not exhibit high ionic conductivity. .
The objective of this invention is providing the lithium ion conductive solid electrolyte sheet which has high ion conductivity, and its manufacturing method.

According to the present invention, the following lithium ion conductive solid electrolyte sheet and method for producing the same are provided.
1. A method for producing a crystalline lithium ion conductive solid electrolyte sheet, wherein a glassy lithium ion conductive solid electrolyte is formed into a sheet and then heat-treated, or formed into a sheet and heat-treated.
A lithium ion conductive solid electrolyte sheet obtained by the production method of 2.1.
3. A positive electrode, a negative electrode, and a solid electrolyte layer sandwiched between the positive electrode and the negative electrode,
A solid secondary battery in which the solid electrolyte layer is manufactured from two lithium ion conductive solid electrolyte sheets.

  ADVANTAGE OF THE INVENTION According to this invention, the lithium ion conductive solid electrolyte sheet which has high ion conductivity, and its manufacturing method can be provided.

In the method for producing a lithium ion conductive solid electrolyte sheet of the present invention, a glassy lithium ion conductive solid electrolyte is formed into a sheet shape and then heat-treated to obtain a crystalline lithium ion conductive solid electrolyte sheet. Alternatively, a glassy lithium ion conductive solid electrolyte is formed into a sheet and heat treated to obtain a crystalline lithium ion conductive solid electrolyte sheet.
The sheet-like shape is a shape that can be used as a battery member as it is or after being cut.
If the glassy electrolyte powder is formed into a sheet and continuously heat-treated, or formed into a sheet and simultaneously heat-treated, a sheet can be produced efficiently.

  The temperature of heat processing is 150 degreeC-360 degreeC normally. Below 150 ° C., in the case of sulfide-based glass, crystallization is unlikely to proceed because the temperature is below the glass transition point. On the other hand, when it exceeds 360 ° C., there is a possibility that a crystal glass having a specific crystal structure described later is not generated. The heat treatment temperature is more preferably 200 ° C to 350 ° C, and particularly preferably 250 ° C to 300 ° C. The heat treatment time is not particularly limited as long as the crystal is generated, and may be instantaneous or long. Moreover, there is no limitation in particular also about the temperature rising pattern to heat processing temperature.

The forming method is not particularly limited as long as the solid electrolyte can be formed into a sheet shape. For example, a forming method such as press molding or roll press molding, a sheet forming method using a coating method such as doctor blade or screen printing, and the like can be given.
When the solid electrolyte is formed into a sheet using a molding method such as press molding, the press pressure is preferably about 0.01 MPa to 1000 MPa. Thereafter, heat treatment is performed in the temperature range described above to produce a sheet, but hot press molding or the like in which heat is applied at the same time as pressing to form a sheet may be used.
On the other hand, when using it for a coating method and making it into a sheet form, the coating composition used there is mainly composed of a solid electrolyte and an organic solvent. You may add binders, such as resin, a thickener, etc. as needed. For example, after applying the coating composition using a doctor blade or the like, drying and forming into a sheet, the solid electrolyte formed into a sheet by pressing or roll pressing is consolidated, and heat treatment is performed in the temperature range described above . You may use the hot press and hot roll press which can be heat-processed simultaneously with compaction.
The organic solvent is not particularly limited as long as it does not adversely affect the solid electrolyte. Preferred organic solvents include hydrocarbons such as heptane and aromatics such as toluene.

According to the present invention, a crystalline solid electrolyte molded article having excellent ionic conductivity can be produced by molding into a sheet using a glassy solid electrolyte and heat-treating it.
This mechanism is considered as follows. Since a glassy solid electrolyte is softer than a solid electrolyte containing a crystal component, the interface of solid particles is likely to fuse (or adhere) when formed by pressing or the like. For this reason, the formation of ion conduction paths becomes dense. The ion conduction path is maintained even if the compact made of the glassy solid electrolyte is heat-treated to form a crystal component. In addition, a dense ion conduction path is formed and maintained even when heat treatment is performed together with molding. As a result, in combination with the improvement in ion conductivity due to the crystal component, a molded article having high ion conductivity is formed.

  The substance which comprises a lithium ion conductive solid electrolyte is not specifically limited, The material which consists of an organic compound, an inorganic compound, or both organic and inorganic compounds can be used, A well-known thing can be used in the lithium ion battery field | area.

In particular, sulfide-based inorganic solid electrolytes are known to have higher ionic conductivity than other inorganic compounds, and inorganic solid electrolytes described in JP-A-4-202024 can be used. Specifically, an inorganic solid electrolyte in which Li ₃ PO ₄ , a halogen, and a halogen compound are appropriately added to an inorganic solid electrolyte composed of a combination of Li ₂ S and SiS ₂ , GeS ₂ , P ₂ S ₅ , B ₂ S _3. Can be used.

Since the lithium ion conductivity is high as the glassy lithium ion conductive solid electrolyte used in the present invention, it is preferable to use a lithium / phosphorous sulfide based electrolyte. Lithium / phosphorous sulfide-based electrolytes include lithium sulfide and diphosphorus pentasulfide (P ₂ S ₅ ), or lithium sulfide and simple phosphorus and simple sulfur, as well as lithium sulfide, diphosphorus pentasulfide, simple phosphorus and / or simple sulfur. Can be manufactured from.

  As lithium sulfide for producing the above lithium / phosphorous sulfide-based electrolyte, those commercially available without limitation can be used, but those having high purity are preferred.

  Preferably, the lithium sulfide has a total content of lithium salts of sulfur oxides of 0.15% by mass or less, more preferably 0.1% by mass or less, and a content of lithium N-methylaminobutyrate of 0.1%. It is 15 mass% or less, More preferably, it is 0.1 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). That is, when the total content of the lithium salt of sulfur oxide exceeds 0.15% by mass, the obtained electrolyte may be a crystallized product from the beginning, and the ionic conductivity of the crystallized product is low. Further, even if this crystallized product is subjected to a heat treatment, the crystallized product is not changed, and there is a possibility that a lithium ion conductive inorganic solid electrolyte having high ion conductivity cannot be obtained.

  Further, 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 battery.

  When lithium sulfide with reduced impurities is used, a high ion conductive electrolyte can be obtained.

The method for producing lithium sulfide used for producing the high ion conductive electrolyte is not particularly limited as long as it is a method that can reduce at least the impurities.
For example, it can be obtained by purifying lithium sulfide produced by the following method.
Among the following production methods, the method a or b is particularly preferable.
a. A method in which lithium hydroxide and hydrogen sulfide are reacted at 0 to 150 ° C. in an aprotic organic solvent to produce lithium hydrosulfide, and this reaction solution is then desulfurized at 150 to 200 ° C. -330312).
b. A method of directly producing lithium sulfide by reacting lithium hydroxide and hydrogen sulfide at 150 to 200 ° C. in an aprotic organic solvent (Japanese Patent Laid-Open No. 7-330312).
c. A method of reacting lithium hydroxide and a gaseous sulfur source at a temperature of 130 to 445 ° C. (Japanese Patent Laid-Open No. 9-283156).

  There is no restriction | limiting in particular as a refinement | purification method of lithium sulfide. As a preferable purification method, for example, the method described in International Publication No. WO2005 / 40039 and the like can be mentioned.

  Specifically, lithium sulfide is washed at a temperature of 100 ° C. or higher using an organic solvent. The organic solvent used for washing is preferably an aprotic polar solvent, and moreover, the aprotic organic solvent used for the production of lithium sulfide and the aprotic polar organic solvent used for washing are more preferably the same. preferable.

  Examples of the aprotic polar organic solvent preferably used for washing include aprotic polar organic compounds such as amide compounds, lactam compounds, urea compounds, organic sulfur compounds, cyclic organophosphorus compounds, Or it can use suitably as a mixed solvent. In particular, N-methyl-2-pyrrolidone (NMP) is selected as a good solvent.

  The amount of the organic solvent used for washing is not particularly limited, and the number of times of washing is not particularly limited, but is preferably 2 or more. Cleaning is preferably performed under an inert gas such as nitrogen or argon.

  The washed lithium sulfide is dried at a temperature equal to or higher than the boiling point of the organic solvent used for washing for 5 minutes or more, preferably about 2 to 3 hours or more under an inert gas stream such as nitrogen under normal pressure or reduced pressure. Thus, lithium sulfide that is suitably used can be obtained.

P ₂ S ₅ can be used without particular limitation as long as it is industrially produced and sold. In place of P ₂ S ₅ , elemental phosphorus (P) and elemental sulfur (S) in a corresponding molar ratio can also be used. Simple phosphorus (P) and simple sulfur (S) can be used without particular limitation as long as they are industrially produced and sold.

The mixing molar ratio of lithium sulfide to diphosphorus pentasulfide and / or simple phosphorus and simple sulfur is usually 50:50 to 80:20, preferably 60:40 to 75:25.
Particularly preferably, it is about Li ₂ S: P ₂ S ₅ = 68: 32 to 74:26 (molar ratio).

  Examples of a method for producing a glassy electrolyte include a melt quenching method and a mechanical milling method (MM method).

In the case of the melt quenching method, a predetermined amount of P ₂ S ₅ and Li ₂ S are mixed in a mortar, and the pellets are placed in a carbon-coated quartz tube and sealed in a vacuum. After reacting at a constant reaction temperature, the glass is put into ice and rapidly cooled to obtain a sulfide glass.

  The reaction temperature at this time is preferably 400 ° C to 1000 ° C, more preferably 800 ° C to 900 ° C. Moreover, reaction time becomes like this. Preferably it is 0.1 to 12 hours, More preferably, it is 1 to 12 hours. The quenching temperature of the reactant is usually 10 ° C. or less, preferably 0 ° C. or less, and the cooling rate is usually about 1 to 10,000 K / sec, preferably 1 to 1000 K / sec.

In the case of the MM method, sulfide glass is obtained by mixing a predetermined amount of P ₂ S ₅ and Li ₂ S in a mortar and reacting them for a certain time by a mechanical milling method.

  The mechanical milling method using the above raw materials can be reacted at room temperature. According to the MM method, since a glassy electrolyte can be produced at room temperature, there is an advantage that a raw material is not thermally decomposed and a glassy electrolyte having a charged composition can be obtained. Further, the MM method has an advantage that the glassy electrolyte can be made into fine powder simultaneously with the production of the glassy electrolyte.

  Although various types of pulverization methods can be used for the MM method, it is particularly preferable to use a planetary ball mill. The planetary ball mill is capable of efficiently generating very high impact energy by rotating the base and revolving while the pot rotates.

  Although the rotation speed and rotation time of the MM method are not particularly limited, the faster the rotation speed, the faster the glassy electrolyte production rate, and the longer the rotation time, the higher the conversion rate of the raw material into the glassy electrolyte.

  For example, when a planetary ball mill is used, the rotational speed may be set to several tens to several hundreds of revolutions / minute, and the treatment may be performed for 0.5 hours to 100 hours.

  Although specific examples of the sulfide glass by the melt quenching method and the MM method have been described above, manufacturing conditions such as temperature conditions and processing time can be appropriately adjusted according to the equipment used.

  A crystalline sulfide glass ceramic (lithium ion conductive solid electrolyte) obtained by heat-treating a sulfide glass sheet is 2θ = 17.8 ± 0.3 deg in X-ray diffraction (CuKα: λ = 1.5418４), 18.2 ± 0.3 deg, 19.8 ± 0.3 deg, 21.8 ± 0.3 deg, 23.8 ± 0.3 deg, 25.9 ± 0.3 deg, 29.5 ± 0.3 deg, 30. It preferably has a diffraction peak at 0 ± 0.3 deg. A solid electrolyte having such a crystal structure has extremely high lithium ion conductivity.

Moreover, it is preferable that the crystalline sulfide glass ceramic obtained by heat-treating the sulfide glass sheet satisfies the following conditions (1) and (2).
(1) The solid ³¹ P-NMR spectrum of the solid electrolyte has peaks due to crystals at 90.9 ± 0.4 ppm and 86.5 ± 0.4 ppm.
(2) The ratio (xc) of crystals that produce the peak (1) in the solid electrolyte is 60 mol% to 100 mol%.
The two peaks of condition (1) are observed when a high ion conductive crystal component is present in the solid electrolyte. Specifically, it is a peak caused by P ₂ S ₇ ^4- and PS ₄ ^3- in the crystal.

Condition (2) defines the ratio xc of the crystal in the solid electrolyte. When a high ion conductive crystal component is present in a predetermined amount or more, specifically 60 mol% or more in the solid electrolyte, lithium ions move mainly through the high ion conductive crystal. Therefore, the lithium ion conductivity is improved as compared with the case of moving a non-crystalline portion (glass portion) in the solid electrolyte or a crystal lattice (for example, P ₂ S ₆ ⁴⁻ ) that does not exhibit high ion conductivity. The ratio xc is preferably 65 mol% to 100 mol%. The crystal ratio xc can be controlled by adjusting the heat treatment time and temperature of the sulfide glass as a raw material.

The solid ³¹ P-NMR spectrum can be measured, for example, using a JNM-CMXP302 NMR apparatus manufactured by JEOL Ltd., with an observation nucleus of ³¹ P, an observation frequency of 121.339 MHz, a measurement temperature of room temperature, and a measurement method. Performed as MAS method.

The method of measuring the ratio xc is to calculate the resonance line observed at 70 to 120 ppm in a solid ³¹ P-NMR spectrum into a Gaussian curve using a nonlinear least square method and calculate from the area ratio of each curve. For details, refer to Japanese Patent Application No. 2005-356889.

  When molding glass-like lithium ion conductive solid electrolytes into sheets, binders (binders, polymer compounds, etc.) and supports (in order to reinforce the strength of the solid electrolyte layer or prevent short circuit of the solid electrolyte itself) Materials, compounds, etc.) can be mixed and combined.

  The solid secondary battery of the present invention includes a positive electrode, a negative electrode, and a solid electrolyte layer sandwiched between the positive electrode and the negative electrode, and the solid electrolyte layer is manufactured from the lithium ion conductive solid electrolyte sheet.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a solid secondary battery according to the present invention.
In the all-solid-state secondary battery 1, a solid electrolyte layer 20 is sandwiched between a pair of electrodes including a positive electrode 10 and a negative electrode 30. Current collectors 40 and 42 are provided on the positive electrode 10 and the negative electrode 30, respectively.

As a positive electrode material used for the positive electrode 10, those used as a positive electrode active material in the battery field can be used. For example, in the sulfide system, titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), iron sulfide (FeS, FeS ₂ ), copper sulfide (CuS), nickel sulfide (Ni ₃ S ₂ ), and the like can be used. Preferably, TiS ₂ can be used.
In the oxide system, bismuth oxide (Bi ₂ O ₃ ), bismuth lead acid (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 can be used. It is also possible to use a mixture of these. Preferably, lithium cobaltate can be used.
In addition to the above, niobium selenide (NbSe ₃ ) can be used.

As a negative electrode material used for the negative electrode 30, what is used as a negative electrode active material in the battery field | area 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 a mixture thereof. Preferably, it is artificial graphite.
Also, an alloy in combination with a metal itself such as metallic lithium, metallic indium, metallic aluminum, metallic silicon, or another element or compound can be used as the negative electrode material.

  In a solid electrode material (electrode material) that is a member of an all-solid battery, in order to improve ion conductivity in addition to electron conductivity, the particles of the electrode material are in close contact with each other, and the junction points and surfaces between the particles are determined. It is important to ensure that there are many ion conduction paths. Therefore, a method is used in which an ion conductive active material such as an electrolyte is mixed to make an electrode material. A solid electrolyte used in the solid electrolyte layer can be used as the electrolyte. As the solid electrolyte in this case, both a glassy solid electrolyte and a crystalline solid electrolyte can be used. In addition, the smaller the space generated in the gap between the polar material particles (the ratio of the volume of the polar material particles to the volume of the polar material particles: the porosity), the denser the polar material layer is and the higher the ionic conductivity.

As a conductive assistant, an electrically conductive substance may be added as appropriate so that electrons move smoothly in the positive electrode active material. The electrically conductive substance is not particularly limited, but a conductive substance such as acetylene black, carbon black, or carbon nanotube or a conductive polymer such as polyaniline, polyacetylene, or polypyrrole is used alone or in combination. Can do.
As the current collectors 40 and 42, a plate or foil made of copper, magnesium, stainless steel, titanium, iron, cobalt, nickel, zinc, aluminum, germanium, indium, lithium, or an alloy thereof is used. it can.

  The electrode can be produced by forming the electrode material (positive electrode material or negative electrode material) in a film shape on at least a part of the current collector. Examples of the film forming method include a blast method, an aerosol deposition method, a cold spray method, a sputtering method, a vapor phase growth method, a thermal spray method, a hot press, and a hot roll press.

The solid secondary battery can be manufactured by bonding and joining the battery members described above. As a method of joining, there are a method in which the respective members are laminated, pressurization, heat fusion, and pressure bonding, a method of pressurization and thermoforming through two rolls (roll to roll), and the like.
Moreover, you may join to the joining surface through the active material which has ion conductivity, and the adhesive material which does not inhibit ion conductivity.
In joining, heat fusion may be performed as long as the crystal structure of the solid electrolyte does not change.

Production Example 1
(1) Production of lithium sulfide (Li ₂ S) In a 10 liter autoclave equipped with a stirring blade, N-methyl-2-pyrrolidone (NMP) 3326.4 g (33.6 mol) and lithium hydroxide 287.4 g (12 mol) ) And heated to 300 rpm and 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. did. 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.

(3) Manufacture of sulfide glass A mixture of Li ₂ S and P ₂ S ₅ (manufactured by Aldrich), prepared as described above, adjusted to a molar ratio of 68:32, about 1 g and 10 balls of alumina balls having a diameter of 10 mm In a 45 mL alumina container and mechanical milling for 20 hours with a planetary ball mill (manufactured by Fritsch: model P-7) in nitrogen at room temperature (25 ° C.) at a rotation speed of 370 rpm. Thus, a sulfide glass as a white yellow powder was obtained.
When the obtained powder was subjected to powder X-ray diffraction measurement (CuKα: λ = 1.5418Å), it showed a broad shape peculiar to an amorphous body. It was confirmed that

Example 1
The powdery sulfide glass obtained in Production Example 1 (3) was placed in a 0.2 mm-thick mold and press-pressed at 1 MPa to prepare a sheet. The obtained sheet was heat-treated at 300 ° C. for 2 hours.

  This sheet was pulverized into powder, and powder X-ray diffraction measurement (CuKα: λ = 1.5418 Å) was performed, and 2θ = 17.8 deg, 18.2 deg, 19.8 deg, 21.8 deg, 23.8 deg, 25 Diffraction peaks were observed at .9 deg, 29.5 deg, 30.0. For this reason, it was confirmed that a crystalline solid electrolyte (glass ceramic) was obtained.

Moreover, the result of having measured the ion conductivity about the sheet | seat showed the high value of 4 * 10 < ^-3 > S / cm.
The ionic conductivity was measured by an alternating current two-terminal method for a sheet coated with carbon paste as an electrode.
Firing (measurement) was performed by starting from room temperature (25 ° C.), raising the temperature to around 250 ° C., and then lowering the temperature to room temperature. It took about 3 hours to raise and lower the temperature.

Example 2
The powdered sulfide glass obtained in Production Example 1 (3) was placed in a mold having a thickness of 0.2 mm, pressed at 300 MPa, and simultaneously hot pressed at 250 ° C. for 1 hour to prepare a sheet. As a result of measuring the ionic conductivity using the same method as in Example 1, it showed a high value of 7 × 10 ⁻³ S / cm.

Comparative Example 1
The powdery sulfide glass obtained in Production Example 1 (3) was heat-treated at 300 ° C. for 2 hours. A sheet was formed from the heat-treated powder in the same manner as in Example 1.
When the obtained sheet was subjected to powder X-ray diffraction measurement in the same manner as in Example 1, the same X-ray diffraction peak as in Example 1 was observed. For this reason, it was confirmed that a crystalline solid electrolyte (glass ceramic) was obtained.
Furthermore, as a result of measuring ionic conductivity in the same manner as in Example 1, it was 1 × 10 ⁻³ S / cm.

  The lithium ion conductive solid electrolyte sheet of the present invention can be used for producing a solid electrolyte layer of a solid secondary battery.

It is a schematic sectional drawing which shows one Embodiment of the solid secondary battery which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 All-solid-state secondary battery 10 Positive electrode 20 Solid electrolyte layer 30 Negative electrode 40,42 Current collector

Claims (3)

  A method for producing a crystalline lithium ion conductive solid electrolyte sheet, wherein a glassy lithium ion conductive solid electrolyte is heat-treated after being formed into a sheet, or formed into a sheet and heat-treated.   A lithium ion conductive solid electrolyte sheet obtained by the production method according to claim 1. A positive electrode, a negative electrode, and a solid electrolyte layer sandwiched between the positive electrode and the negative electrode,
A solid secondary battery in which the solid electrolyte layer is manufactured from the lithium ion conductive solid electrolyte sheet according to claim 2.

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