JP2023143399A - Solid electrolyte, battery, electronic apparatus, method of manufacturing solid electrolyte, and method of manufacturing battery - Google Patents

Abstract

To provide a solid electrolyte capable of appropriately maintaining a high total ionic conductivity even under an atmosphere, to provide a method of manufacturing the solid electrolyte, to manufacture a battery that includes the solid electrolyte, to provide a method of manufacturing the battery, and to provide an electronic apparatus that comprises the battery.SOLUTION: A solid electrolyte is represented by the following composition formula (1): (Li7-3xGax)(La3-y-mNdyYm)Zr2O12. (In the formula (1), 0.10≤x<1.00, 0.01≤y≤0.20, and 0.00<m≤0.15 are satisfied.)SELECTED DRAWING: None

Description

The present invention relates to a solid electrolyte, a battery, an electronic device, a method for manufacturing a solid electrolyte, and a method for manufacturing a battery.

Lithium ion batteries (including primary batteries and secondary batteries) are used as power sources for many electrical devices including portable information devices. Among these, an all-solid-state lithium ion battery that uses a solid electrolyte to conduct lithium between positive and negative electrodes has been proposed as a lithium ion battery that has both high energy density and safety (see, for example, Patent Document 1).

Solid electrolytes are attracting attention as highly safe materials because they can conduct lithium ions without using an organic electrolyte and do not cause electrolyte leakage or volatilization due to heat generation during driving.

As solid electrolytes used in such all-solid-state lithium ion batteries, oxide-based solid electrolytes are widely known, which have high lithium ion conductivity, excellent insulation properties, and high chemical stability. Among such oxides, lanthanum lithium zirconate-based materials have particularly high lithium ion conductivity and are expected to be applied to batteries.

Japanese Patent Application Publication No. 2009-215130

However, since such solid electrolytes have high lithium ion conductivity, lithium carbonate is easily generated due to the presence of moisture or carbon dioxide in the atmosphere, and the lithium ion conductivity tends to decrease over time. There was a problem.

The present invention has been made to solve the above-mentioned problems, and can be realized as the following application examples.

A solid electrolyte according to an application example of the present invention is represented by the following compositional formula (1).
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

Further, a battery according to an application example of the present invention includes a composite including a solid electrolyte and an active material according to an application example of the present invention;
an electrode provided on one side of the composite;
and a current collector provided on the other surface of the composite.
Further, an electronic device according to an application example of the present invention includes a battery according to an application example of the present invention.

Further, the method for producing a solid electrolyte according to an application example of the present invention includes mixing a plurality of types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1), a first mixing step to obtain a mixture;
a first heating step of subjecting the first mixture to a first heat treatment to form a pre-fired body;
and a second heating step of performing a second heat treatment on the pre-fired body to form a crystalline solid electrolyte represented by the following compositional formula (1).
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

In addition, a method for producing a solid electrolyte according to another application example of the present invention is to mix a plurality of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1), a first mixing step to obtain a first mixture;
a heating step of subjecting the first mixture to a heat treatment to form a first electrolyte portion;
Forming a second electrolyte part by melting the second electrolyte with a second electrolyte containing Li, B, and O in contact with the first electrolyte part to form a second electrolyte part in contact with the first electrolyte part. It comprises a process.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

In addition, the method for manufacturing a battery according to an application example of the present invention includes dissolving and mixing multiple types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1) in a solvent. a first mixing step of obtaining a first mixture;
a first molded body forming step of forming a first molded body using an active material;
a composite forming step of heating the first mixture impregnated in the first molded body to form a composite containing a crystalline first electrolyte portion and the active material;
an electrode forming step of forming an electrode on one side of the composite;
A method for manufacturing a battery, comprising a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

Further, a method for manufacturing a battery according to another application example of the present invention includes dissolving in a solvent a plurality of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1), a first mixing step of mixing to obtain a first mixture;
a first molded body forming step of forming a first molded body using an active material;
a second molded body forming step of heating the first mixture impregnated in the first molded body to form a second molded body containing a crystalline first electrolyte portion and the active material; and,
A second electrolyte containing Li, B, and O is brought into contact with the second molded body, the second electrolyte is melted, and the second molded body is filled with the melt of the second electrolyte, and then , a composite forming step of cooling the second molded body filled with the melt of the second electrolyte to form a composite including the first electrolyte part, the second electrolyte part, and the active material;
an electrode forming step of forming an electrode on one side of the composite;
and a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

In addition, a method for manufacturing a battery according to another application example of the present invention is to mix a plurality of types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1), a first mixing step to obtain a mixture;
a step of forming a pre-fired body by subjecting the first mixture to a first heat treatment to obtain a pre-fired body;
a second mixing step of mixing the pre-fired body and the active material to obtain a second mixture;
a third molded body forming step of molding the second mixture to form a third molded body;
a composite forming step of subjecting the third molded body to a second heat treatment to form a composite containing a crystalline first electrolyte portion and the active material;
an electrode forming step of forming an electrode on one side of the composite;
and a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

In addition, a method for manufacturing a battery according to another application example of the present invention includes mixing a plurality of types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1), a first mixing step to obtain a mixture;
a step of forming a pre-fired body by subjecting the first mixture to a first heat treatment to obtain a pre-fired body;
a second mixing step of mixing the pre-fired body and the active material to obtain a second mixture;
a third molded body forming step of molding the second mixture to form a third molded body;
a second molded body forming step of subjecting the third molded body to a second heat treatment to form a second molded body containing a crystalline first electrolyte portion and the active material;
A second electrolyte containing Li, B, and O is brought into contact with the second molded body, the second electrolyte is melted, and the second molded body is filled with the melt of the second electrolyte, and then , a composite forming step of cooling the second molded body filled with the melt of the second electrolyte to form a composite including the first electrolyte part, the second electrolyte part, and the active material;
an electrode forming step of forming an electrode on one side of the composite;
and a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

FIG. 1 is a vertical cross-sectional view schematically showing a method for manufacturing a solid electrolyte according to a first embodiment. FIG. 2 is a vertical cross-sectional view schematically showing a method for manufacturing a solid electrolyte according to a second embodiment. FIG. 3 is a schematic perspective view schematically showing the configuration of a lithium ion battery as a battery of a preferred embodiment. FIG. 4 is a flowchart showing a method for manufacturing a battery according to the first embodiment. FIG. 5 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the first embodiment. FIG. 6 is a vertical cross-sectional view schematically showing a method for manufacturing a battery as the battery of the first embodiment. FIG. 7 is a flowchart showing a method for manufacturing a battery according to the second embodiment. FIG. 8 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the second embodiment. FIG. 9 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the second embodiment. FIG. 10 is a flowchart showing a method for manufacturing a battery according to the third embodiment. FIG. 11 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the third embodiment. FIG. 12 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the third embodiment. FIG. 13 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the third embodiment. FIG. 14 is a flowchart showing a method for manufacturing a battery according to the fourth embodiment. FIG. 15 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the fourth embodiment. FIG. 16 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the fourth embodiment. FIG. 17 is a vertical cross-sectional view schematically showing a method for manufacturing a battery according to the fourth embodiment. FIG. 18 is a perspective view showing the configuration of a wearable device as an electronic device.

Hereinafter, preferred embodiments of the present invention will be described in detail.
[1] Solid Electrolyte First, the solid electrolyte of the present invention will be explained.

The solid electrolyte of the present invention is represented by the following compositional formula (1).
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.)

By satisfying such conditions, it is possible to provide a solid electrolyte that can suitably maintain a high total ionic conductivity even under the atmosphere. More specifically, by substituting a part of the lanthanum site of a lanthanum lithium zirconate-based material with Nd and Y, and by substituting a part of the lithium site with Ga, the acid resistance becomes stronger and It is possible to provide a solid electrolyte that can suppress the generation of lithium carbonate and exhibits high total ionic conductivity even in the atmosphere.

On the other hand, unless the above conditions are satisfied, the above excellent effects cannot be obtained.

For example, if the solid electrolyte does not contain Y, even if the initial total ionic conductivity can be made relatively high, it is difficult to maintain a high total ionic conductivity even in the atmosphere. It becomes difficult.

Further, if the solid electrolyte does not contain Nd, even if it is possible to suppress a decrease in the total ionic conductivity when placed in the atmosphere, the initial total ionic conductivity itself cannot be sufficiently increased.

Furthermore, if the solid electrolyte does not contain Ga, even if it is possible to suppress a decrease in the total ionic conductivity when placed in the atmosphere, it will be difficult to sufficiently increase the initial total ionic conductivity itself.

Furthermore, even if the solid electrolyte is a lanthanum lithium zirconate material containing Nd, Y, and Ga, if the content of Y in the solid electrolyte is too high, in other words, if the value of m is too large, Even if it is possible to suppress the decrease in the total ionic conductivity when exposed to air, it becomes difficult to sufficiently increase the initial total ionic conductivity itself.

Furthermore, even if the solid electrolyte is a lanthanum lithium zirconate material containing Nd, Y, and Ga, if the content of Nd in the solid electrolyte is too low, in other words, if the value of y is too small, Even if it is possible to suppress the decrease in the total ionic conductivity when exposed to air, it becomes difficult to sufficiently increase the initial total ionic conductivity itself.

Furthermore, even if the solid electrolyte is a lanthanum lithium zirconate material containing Nd, Y, and Ga, if the content of Nd in the solid electrolyte is too high, in other words, if the value of y is too large, Even if it is possible to suppress the decrease in the total ionic conductivity when exposed to air, it becomes difficult to sufficiently increase the initial total ionic conductivity itself.

Furthermore, even if the solid electrolyte is a lanthanum lithium zirconate material containing Nd, Y, and Ga, if the Ga content in the solid electrolyte is too low, in other words, if the value of x is too small, Even if it is possible to suppress the decrease in the total ionic conductivity when exposed to air, it becomes difficult to sufficiently increase the initial total ionic conductivity itself.

Furthermore, even if the solid electrolyte is a lanthanum lithium zirconate material containing Nd, Y, and Ga, if the Ga content in the solid electrolyte is too high, in other words, if the value of x is too large, Even if it is possible to suppress the decrease in the total ionic conductivity when exposed to air, it becomes difficult to sufficiently increase the initial total ionic conductivity itself.

As mentioned above, in the above compositional formula (1), x only needs to satisfy the condition of 0.10≦x<1.00, but it is preferable that x satisfies the condition of 0.15≦x≦0.95. It is preferable that the condition of 0.20≦x≦0.90 is satisfied, and it is even more preferable that the condition of 0.25≦x≦0.80 is satisfied.Thereby, the above-mentioned effect is more prominently exhibited. .

As mentioned above, in the above compositional formula (1), y only needs to satisfy the condition of 0.01≦y≦0.20, but it is preferable that y satisfy the condition of 0.02≦y≦0.18. It is preferable to satisfy the condition of 0.03≦y≦0.16, and even more preferably to satisfy the condition of 0.04≦y≦0.10.
Thereby, the above-mentioned effects are more prominently exhibited.

As mentioned above, in the above compositional formula (1), m should satisfy the condition of 0.00<m≦0.15, but it is preferable that m satisfies the condition of 0.01≦m≦0.12. It is preferable that the condition of 0.02≦m≦0.10 is satisfied, and it is even more preferable that the condition of 0.02≦m≦0.07 is satisfied.
Thereby, the above-mentioned effects are more prominently exhibited.

In the solid electrolyte, Li mainly exists at C sites and interstitial positions in the basic skeleton of the garnet-type lithium ion conductor Li ₇ La ₃ Zr ₂ O ₁₂ and contributes to lithium ion conductivity.

In the solid electrolyte, La mainly constitutes the basic skeleton of the garnet-type lithium ion conductor Li ₇ La ₃ Zr ₂ O ₁₂ and occupies the A site as La ³⁺ .

In the solid electrolyte, Zr mainly constitutes the basic skeleton of the garnet-type lithium ion conductor Li ₇ La ₃ Zr ₂ O ₁₂ and occupies the B site as Zr ⁴⁺ .

In the solid electrolyte, Ga mainly functions to widen the movement path of lithium ions and increase the lithium ion conductivity.

In the solid electrolyte, Nd mainly promotes the grain growth mode during firing and reduces the formation of grain boundaries, thereby reducing grain boundary resistance and improving the total lithium ion conductivity. .

In the solid electrolyte, Y mainly has the effect of increasing the oxidation resistance of the solid electrolyte, and functions to suppress carbonation of lithium in the electrolyte and increase in resistance.

The solid electrolyte of the present invention contains, in addition to the elements constituting the above compositional formula (1), other elements, that is, elements other than Li, Ga, La, Nd, Y, Zr, and O, even in trace amounts. It may also be included. The number of the other elements may be one or two or more.

The content of the other elements contained in the solid electrolyte of the present invention is preferably 100 ppm or less, more preferably 50 ppm or less.

When two or more types of elements are included as the other elements, the sum of the content rates of these elements shall be adopted as the content rate of the other elements.

The crystal phase of the solid electrolyte of the present invention is usually a cubic garnet type crystal.
The solid electrolyte of the present invention may be used alone or in combination with other components, for example. More specifically, the solid electrolyte of the present invention may be used alone to constitute a solid electrolyte layer in a battery, or may be used as a solid electrolyte layer in a mixed state with other solid electrolytes. It may also constitute a layer. Further, for example, the solid electrolyte of the present invention may be mixed with a positive electrode active material to form a positive electrode layer, or may be mixed with a negative electrode active material to form a negative electrode layer.

[2] Method for manufacturing solid electrolyte Next, the method for manufacturing solid electrolyte of the present invention will be described.
The method for manufacturing a solid electrolyte of the present invention is a method for manufacturing a solid electrolyte including a solid electrolyte represented by the above compositional formula (1).
In the following description, the solid electrolyte represented by the above compositional formula (1) is also referred to as a first electrolyte.

[2-1] First Embodiment A method for producing a solid electrolyte according to the first embodiment will be described below.
FIG. 1 is a vertical cross-sectional view schematically showing a method for manufacturing a solid electrolyte according to a first embodiment.

As shown in FIG. 1, the method for manufacturing the solid electrolyte of the present embodiment includes mixing multiple types of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above composition formula (1), A first mixing step (1A) for obtaining a first mixture P1, a first heating step (1B) for subjecting the first mixture P1 to a first heat treatment to form a pre-fired body P2, and a second heating for the pre-fired body P2. A second heating step (1C) is provided to form a crystalline solid electrolyte P3' represented by the above compositional formula (1), that is, a first electrolyte P3'.

Thereby, it is possible to provide a method for producing a solid electrolyte that can produce solid electrolyte P100 that can suitably maintain a high total ionic conductivity even in the atmosphere. More specifically, by substituting a part of the lanthanum site of a lanthanum lithium zirconate-based material with Nd and Y, and by substituting a part of the lithium site with Ga, the acid resistance becomes stronger and It is possible to provide a method for producing a solid electrolyte that can suppress the production of lithium carbonate and produce a solid electrolyte P100 that exhibits high total ionic conductivity even in the atmosphere.

Note that in the illustrated configuration, the entire solid electrolyte P100 finally obtained is a first electrolyte portion P3 that is substantially composed only of the first electrolyte P3'; It may have a part composed of other components.

[2-1-1] Mixing Step In the mixing step, a first mixture P1 is obtained by mixing a plurality of types of raw materials containing the metal element contained in the above composition formula (1).

In this step, the entire first mixture P1 obtained by mixing a plurality of types of raw materials only needs to contain two or more types of metal elements among the metal elements included in the above compositional formula (1).

Furthermore, at least one of the plurality of raw materials used in this step may be an oxo acid compound containing an oxo anion as well as a metal ion.

Thereby, the first electrolyte P3' and the solid electrolyte P100 having desired characteristics can be stably formed by heat treatment at a relatively low temperature and in a relatively short time. More specifically, by using the oxoacid compound in this step, it is possible to obtain the calcined body P2 in a later step as one containing an oxide different from the first electrolyte P3′ and the oxoacid compound. can. As a result, it is possible to lower the melting point of the oxide and form an adhesive interface with the adherend while promoting crystal growth through baking treatment, which is heat treatment at a relatively low temperature and for a relatively short time.

The oxo anions constituting the oxo acid compound do not contain metal elements, and include, for example, halogen oxo acids; borate ions; carbonate ions; orthocarbonate ions; carboxylate ions; silicate ions; nitrite ions; nitrate ions. ; phosphite ion; phosphate ion; arsenate ion; sulfite ion; sulfate ion; sulfonate ion; sulfinate ion and the like. Examples of halogen oxo acids include hypochlorite ion, chlorite ion, chlorate ion, perchlorate ion, hypobromite ion, bromite ion, bromate ion, perbromate ion, and hypochlorite ion. Examples include iodate ion, iodate ion, iodate ion, periodate ion, and the like. Among these, the oxo acid compound preferably contains at least one of a nitrate ion and a sulfate ion, and more preferably a nitrate ion, as an oxoanion.

Thereby, the melting point of the metal oxide contained in the pre-fired body P2 obtained in the first heating step, which will be described in detail later, is lowered more appropriately, and the crystal growth of the lithium-containing double oxide is more effectively promoted. I can do it. As a result, even when the second heating step, which will be detailed later, is performed at a lower temperature and for a shorter time, it is possible to suitably obtain the first electrolyte P3' and the solid electrolyte P100, which have particularly excellent ionic conductivity. . In the following description, the metal oxide contained in the calcined body P2 obtained in the first heating step is also referred to as a "precursor oxide."

As raw materials containing metal elements, for example, single metals or alloys may be used, compounds containing only one type of metal element in the molecule, or compounds containing multiple types of metal elements in the molecule. You may use the compound containing.

Examples of the lithium compound that is a raw material containing Li include lithium metal salts, lithium alkoxides, and the like, and one or more of these can be used in combination. Examples of the lithium metal salt include lithium chloride, lithium nitrate, lithium sulfate, lithium acetate, lithium hydroxide, lithium carbonate, and (2,4-pentanedionato)lithium. Examples of lithium alkoxides include lithium methoxide, lithium ethoxide, lithium propoxide, lithium isopropoxide, lithium butoxide, lithium isobutoxide, lithium secondary butoxide, lithium tertiary butoxide, dipivaloylmethanatritium, and the like. Can be mentioned. Among these, the lithium compound is preferably one or more selected from the group consisting of lithium nitrate, lithium sulfate, and (2,4-pentanedionato)lithium. A hydrate may be used as the raw material containing Li.

Examples of the lanthanum compound that is a raw material containing La include lanthanum metal salts, lanthanum alkoxides, lanthanum hydroxide, etc., and one or more of these can be used in combination. Examples of the lanthanum metal salt include lanthanum chloride, lanthanum nitrate, lanthanum sulfate, lanthanum acetate, and tris(2,4-pentanedionato)lanthanum. Examples of the lanthanum alkoxide include lanthanum trimethoxide, lanthanum triethoxide, lanthanum tripropoxide, lanthanum triisopropoxide, lanthanum tributoxide, lanthanum triisobutoxide, lanthanum trisecondary butoxide, lanthanum triteributoxide, and Examples include baloylmetanatolantane. Among these, the lanthanum compound is preferably at least one selected from the group consisting of lanthanum nitrate, lanthanum tris(2,4-pentanedionato), and lanthanum hydroxide. A hydrate may be used as the raw material containing La.

Examples of the yttrium compound that is a raw material containing Y include yttrium metal salts, yttrium alkoxides, yttrium hydroxide, etc., and one or more of these can be used in combination. Examples of the yttrium metal salt include yttrium chloride, yttrium nitrate, yttrium sulfate, yttrium acetate, and tris(2,4-pentanedionato)yttrium. Examples of yttrium alkoxide include yttrium trimethoxide, yttrium triethoxide, yttrium tripropoxide, yttrium triisopropoxide, yttrium tributoxide, yttrium triisobutoxide, yttrium trisecondary butoxide, yttrium triteributoxide, and dipytrium. Examples include baloylmethanatoyttrium. Among these, the yttrium compound is preferably at least one selected from the group consisting of yttrium nitrate, tris(2,4-pentanedionato)yttrium, and yttrium hydroxide. A hydrate may be used as the raw material containing Y.

Examples of the zirconium compound that is a raw material containing Zr include zirconium metal salts, zirconium alkoxides, and the like, and one or more of these can be used in combination. Examples of the zirconium metal salt include zirconium chloride, zirconium oxychloride, zirconium oxynitrate, zirconium oxysulfate, zirconium oxyacetate, and zirconium acetate. Examples of the zirconium alkoxide include zirconium tetramethoxide, zirconium tetraethoxide, zirconium tetrapropoxide, zirconium tetraisopropoxide, zirconium tetranormal butoxide, zirconium tetraisobutoxide, zirconium tetrasecondary butoxide, and zirconium tetratertiary butoxide. , dipivaloylmethanatozirconium, and the like. Among these, zirconium tetranormal butoxide is preferred as the zirconium compound. A hydrate may be used as the raw material containing Zr.

Examples of the neodymium compound, which is a raw material containing Nd, include neodymium metal salts, neodymium alkoxide, neodymium hydroxide, etc., and one or more of these can be used in combination. Examples of neodymium metal salts include neodymium chloride, neodymium nitrate, neodymium sulfate, neodymium acetate, and the like. Examples of neodymium alkoxides include neodymium trimethoxide, neodymium triethoxide, neodymium tripropoxide, neodymium triisopropoxide, neodymium tributoxide, neodymium triisobutoxide, neodymium trisec- butoxide, neodymium triteributoxide, dipyni Examples include baloylmethanatone neodymium. Among these, neodymium nitrate is preferred as the neodymium compound. A hydrate may be used as the raw material containing Nd.

Examples of the gallium compound, which is a raw material containing Ga, include gallium metal salts, gallium alkoxides, gallium hydroxide, etc., and one or more of these can be used in combination. Examples of gallium metal salts include gallium chloride, gallium nitrate, gallium sulfate, and gallium acetate. Examples of gallium alkoxides include gallium trimethoxide, gallium triethoxide, gallium tripropoxide, gallium triisopropoxide, gallium tributoxide, gallium triisobutoxide, gallium trisecondary butoxide, gallium triteributoxide, and dipypoxide. Examples include baloylmethanatogallium. Among these, gallium nitrate is preferred as the gallium compound. A hydrate may be used as the raw material containing Ga.

A solvent may be used to prepare the first mixture P1.
Thereby, multiple types of raw materials containing the metal elements included in the above compositional formula (1) can be mixed more suitably.

The solvent is not particularly limited and, for example, various organic solvents can be used, but more specifically, for example, alcohols, glycols, ketones, esters, ethers, organic acids, aromatic Examples include families, amides, etc., and a mixed solvent that is one or a combination of two or more selected from these can be used. Examples of alcohols include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, allyl alcohol, and 2-n-butoxyethanol. Examples of glycols include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, pentanediol, hexanediol, heptanediol, dipropylene glycol, and the like. Examples of ketones include dimethyl ketone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, and the like. Examples of esters include methyl formate, ethyl formate, methyl acetate, and methyl acetoacetate. Examples of the ethers include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, and the like. Examples of organic acids include formic acid, acetic acid, 2-ethylbutyric acid, propionic acid, and the like. Examples of aromatics include toluene, o-xylene, p-xylene, and the like. Examples of amides include formamide, N,N-dimethylformamide, N,N-diethylformamide, dimethylacetamide, and N-methylpyrrolidone. Among these, the solvent is preferably at least one of 2-n-butoxyethanol and propionic acid.

When a solvent is used to prepare the first mixture P1, at least a portion of the solvent may be removed prior to the first heating step described in detail later.

Removal of the solvent prior to the first heating step can be performed, for example, by heating the first mixture P1, placing it in a reduced pressure environment, or placing it at normal temperature and normal pressure. By removing at least a portion of the solvent, the first mixture P1 can be suitably gelled. Note that in this specification, normal temperature and normal pressure refers to 25° C. and 1 atm.

Hereinafter, when the solvent is removed by heat treatment, the heat treatment is also referred to as preliminary heat treatment.
The conditions for the preheating treatment depend on the boiling point, vapor pressure, etc. of the solvent, but the heating temperature for the preheating treatment is preferably 50°C or more and 250°C or less, more preferably 60°C or more and 230°C or less, More preferably, the temperature is 80°C or higher and 200°C or lower. During the preheating treatment, the heating temperature may be changed. For example, the preliminary heat treatment may include a first stage in which the heat treatment is performed while maintaining the temperature at a relatively low temperature, and a second stage in which the temperature is raised after the first stage and the heat treatment is performed at a relatively high temperature. . In such a case, it is preferable that the maximum temperature during the preheating treatment is within the above-mentioned range.

Further, the heating time in the preheating treatment is preferably 10 minutes or more and 180 minutes or less, more preferably 20 minutes or more and 120 minutes or less, and even more preferably 30 minutes or more and 60 minutes or less.

The preheating treatment may be performed in any atmosphere, and may be performed in an oxidizing atmosphere such as air or an oxygen gas atmosphere, or in a non-oxidizing atmosphere such as an inert gas such as nitrogen gas, helium gas, or argon gas. It may be done in an atmosphere. Further, the preheating treatment may be performed under reduced pressure, vacuum, or increased pressure.

Further, during the preliminary heat treatment, the atmosphere may be maintained under substantially the same conditions or may be changed to different conditions. For example, the preliminary heat treatment may include a first stage of heat treatment in a normal pressure environment, and a second stage of heat treatment in a reduced pressure environment after the first stage.

[2-1-2] First heating step In the first heating step, the first mixture P1 obtained in the mixing step, for example, the gelled first mixture P1, is subjected to a first heat treatment to form a pre-fired body P2. shall be.

In particular, when an oxoacid compound is used as a part of the raw materials, a pre-calcined body P2 containing the oxoacid compound and a precursor oxide which is an oxide different from the first electrolyte P3' is obtained.

The heating temperature in the first heating step is not particularly limited, but is preferably 500°C or more and 650°C or less, more preferably 510°C or more and 650°C or less, and preferably 520°C or more and 600°C or less. More preferred.

Thereby, it is possible to more effectively prevent the metal elements that should constitute the first electrolyte P3' from being vaporized inadvertently, especially the vaporization of Li, which is easily volatile in metal materials. The composition of the first electrolyte P3' can be controlled more strictly, and the first electrolyte P3' and the solid electrolyte P100 can be manufactured more efficiently.

During the first heating step, the heating temperature may be changed. For example, the first heating step may include a first stage in which heat treatment is performed while maintaining the temperature at a relatively low temperature, and a second stage in which the temperature is raised after the first stage and heat treatment is performed at a relatively high temperature. good. In such a case, it is preferable that the maximum temperature in the first heating step is within the above range.

Further, the heating time in the first heating step, especially the heating time at a heating temperature of 500°C or more and 650°C or less, is preferably 5 minutes or more and 180 minutes or less, and preferably 10 minutes or more and 120 minutes or less. More preferably, the duration is 15 minutes or more and 90 minutes or less.

The first heating step may be performed in any atmosphere, and may be performed in an oxidizing atmosphere such as air or an oxygen gas atmosphere, or in a non-oxidizing atmosphere such as an inert gas such as nitrogen gas, helium gas, or argon gas. It may take place in a sexual atmosphere. Further, the first heating step may be performed under reduced pressure, vacuum, or increased pressure. In particular, the first heating step is preferably performed in an oxidizing atmosphere.

Further, during the first heating step, the atmosphere may be maintained under substantially the same conditions or may be changed to different conditions. For example, the first heating step may include a first step of performing heat treatment in an inert gas atmosphere, and a second step of performing heat treatment in an oxidizing atmosphere after the first step.

The pre-fired body P2 obtained as described above usually contains the first electrolyte P3', that is, a precursor oxide having a crystal phase different from that of the solid electrolyte represented by the composition formula (1) at room temperature and normal pressure. I'm here. In this specification, the term "different" with respect to crystal phases is a broad concept that includes not only crystal phases of different types, but also those of the same type but different in at least one lattice constant.

Examples of the crystal phase of the precursor oxide include cubic crystals such as pyrochlore type crystal, perovskite structure, rock salt type structure, diamond structure, fluorite type structure, spinel type structure, orthorhombic type such as ramsdellite type, corundum type, etc. Examples include trigonal crystals, but pyrochlore crystals are preferred.

Thereby, even when the conditions in the second heating step described below are set to a lower temperature and a shorter time, a solid electrolyte having particularly excellent ionic conductivity can be suitably obtained.

Although the crystal grain size of the precursor oxide is not particularly limited, it is preferably 10 nm or more and 200 nm or less, more preferably 15 nm or more and 180 nm or less, and even more preferably 20 nm or more and 160 nm or less.

As a result, the melting temperature of the precursor oxide and the firing temperature in the second heating step can be further lowered due to the so-called Gibbs-Thomson effect, which is a phenomenon in which the melting point decreases as the surface energy increases. It is also advantageous in improving the bonding between the solid electrolyte P100 produced using the method of the present invention and different materials, and in reducing defect density.

Preferably, the precursor oxide is composed of substantially a single crystalline phase.
As a result, when producing solid electrolyte P100 using the method of the present invention, that is, when a high-temperature crystal phase is generated, there is substantially only one crystal phase transition, so element segregation due to crystal phase transition The formation of contaminant crystals due to heat decomposition and thermal decomposition is suppressed, and various properties of the produced solid electrolyte P100 are further improved.

In addition, when measuring the pre-fired body P2 obtained in the first heating step with a TG-DTA at a temperature increase rate of 10 °C/min, only one exothermic peak was observed in the range of 300 °C or more and 1,000 °C or less. If so, it can be determined that the material is "substantially composed of a single crystalline phase."

Although the composition of the precursor oxide is not particularly limited, it is preferable that the precursor oxide is a double oxide. In particular, the precursor oxide is preferably a double oxide containing La and Y.

Thereby, even when the heat treatment in the second heating step described below is performed at a lower temperature and for a shorter time, it is possible to suitably obtain solid electrolyte P100 having particularly excellent ionic conductivity. In addition, for example, in an all-solid-state secondary battery, it is possible to improve the adhesion of the first electrolyte P3' to the positive electrode active material and the negative electrode active material, and to form a composite material to have a better adhesion interface. Therefore, the characteristics and reliability of the all-solid-state secondary battery can be improved.

Further, in the pre-fired body P2 obtained as described above, most of the solvent used in the manufacturing process is usually removed, but some solvent may remain. However, the content of the solvent in the pre-fired body P2 is preferably 1.0% by mass or less, more preferably 0.1% by mass or less.

[2-1-3] Second heating step In the second heating step, the pre-fired body P2 obtained in the first heating step is subjected to a second heat treatment to form a crystalline substance represented by the above composition formula (1). A solid electrolyte (first electrolyte) P3' is formed.

In particular, when the pre-calcined body P2 obtained in the first heating step contains an oxoacid compound, it is possible to suitably lower the melting point of the precursor oxide, promote crystal growth of the lithium-containing double oxide, and relatively The first electrolyte P3' having desired characteristics can be stably formed by heat treatment at a low temperature and in a relatively short time. Further, it is possible to improve the adhesion between the formed solid electrolyte P100 and the adherend.

Note that the second heating step may be performed after other components are mixed into the above-mentioned pre-fired body P2.
For example, the second heating step may be performed on the mixture of the calcined body P2 and the oxoacid compound.
Even in such a case, the same effects as described above can be obtained.

Here, as a specific example of the oxoacid compound that can be mixed with the calcined body P2, there may be mentioned an oxoacid compound contained in the metal compound exemplified as the raw material of the first mixture P1 described above.

In the second heating step, the above-mentioned pre-fired body P2 may be subjected to the heating step in a state where it is mixed with an active material such as a positive electrode active material or a negative electrode active material.
The positive electrode active material and negative electrode active material will be detailed later.

The composition to be subjected to the second heating step as a whole contains multiple types of metal elements as constituent elements of the first electrolyte P3', and usually, the ratio of these contents is such that the solid electrolyte is of interest. , that is, the content ratio of each metal element in the above compositional formula (1).

When the composition to be subjected to this step contains an oxo acid compound, the content of the oxo acid compound in the composition is not particularly limited, but is preferably 0.1% by mass or more and 20% by mass or less. , more preferably 1.5% by mass or more and 15% by mass or less, and even more preferably 2.0% by mass or more and 10% by mass or less.

As a result, the heat treatment in the second heating step can be suitably performed at a lower temperature and in a shorter time, while more reliably preventing the oxoacid compound from remaining in the solid electrolyte P100. The resulting solid electrolyte P100 can have particularly excellent ionic conductivity.

The content of the precursor oxide in the composition to be subjected to this step is not particularly limited, but is preferably 35% by mass or more and 85% by mass or less, more preferably 45% by mass or more and 90% by mass or less. preferable.

When the content of the precursor oxide in the composition to be subjected to this step is XP [mass%], and the content of the oxoacid compound in the composition to be subjected to this process is XO [mass%], 0 It is preferable to satisfy the relationship of .013≦XO/XP≦0.58, more preferably to satisfy the relationship of 0.023≦XO/XP≦0.34, and 0.03≦XO/XP≦0. It is more preferable that the relationship of No. 19 be satisfied.

As a result, the heat treatment in the second heating step can be suitably performed at a lower temperature and in a shorter time, while more reliably preventing the oxoacid compound from remaining in the solid electrolyte P100. The resulting solid electrolyte can have particularly excellent ionic conductivity.

The heating temperature in the second heating step is not particularly limited, but is usually higher than the heating temperature in the first heating step, preferably 800°C or more and 1000°C or less, and 800°C or more and 950°C or less. More preferably, the temperature is 800°C or more and 900°C or less.

Thereby, solid electrolyte P100 having desired characteristics can be stably formed by heat treatment at a relatively low temperature and in a relatively short time. Furthermore, since the solid electrolyte P100 can be manufactured by heat treatment at a relatively low temperature and in a relatively short time, for example, the productivity of the solid electrolyte P100 and all solid-state batteries including the solid electrolyte can be improved. At the same time, it is preferable from the viewpoint of energy saving.

During the second heating step, the heating temperature may be changed. For example, the second heating step may include a first stage in which heat treatment is performed while maintaining the temperature at a relatively low temperature, and a second stage in which the temperature is raised after the first stage and heat treatment is performed at a relatively high temperature. good. In such a case, it is preferable that the maximum temperature in the second heating step is within the above-mentioned range.

The heating time in the second heating step, particularly the heating time at a heating temperature of 800°C or higher and 1000°C or lower, is not particularly limited, but is preferably 5 minutes or more and 600 minutes or less, and 10 minutes or more and 540 minutes or less. More preferably, the duration is 15 minutes or more and 500 minutes or less.

Thereby, solid electrolyte P100 having desired characteristics can be stably formed by heat treatment at a relatively low temperature and in a relatively short time. Furthermore, since the solid electrolyte P100 can be manufactured by heat treatment at a relatively low temperature and in a relatively short time, for example, the productivity of the solid electrolyte P100 and all solid-state batteries including the solid electrolyte can be improved. At the same time, it is preferable from the viewpoint of energy saving.

The second heating step may be performed in any atmosphere, and may be performed in an oxidizing atmosphere such as air or an oxygen gas atmosphere, or in a non-oxidizing atmosphere such as an inert gas such as nitrogen gas, helium gas, or argon gas. It may take place in a sexual atmosphere. Further, the heating step may be performed under reduced pressure, vacuum, or increased pressure. In particular, the second heating step is preferably performed in an oxidizing atmosphere.

Further, during the second heating step, the atmosphere may be maintained under substantially the same conditions or may be changed to different conditions.

Even when an oxo acid compound is used as a raw material, the solid electrolyte P100 obtained as described above usually does not substantially contain the oxo acid compound. More specifically, the content of the oxoacid compound in the obtained solid electrolyte is usually 100 ppm or less, particularly preferably 50 ppm or less, and more preferably 10 ppm or less.

Thereby, the content of undesirable impurities in the solid electrolyte P100 can be suppressed, and the properties and reliability of the solid electrolyte can be improved.

[2-2] Second Embodiment Next, a method for manufacturing a solid electrolyte according to a second embodiment will be described.
FIG. 2 is a vertical cross-sectional view schematically showing a method for manufacturing a solid electrolyte according to a second embodiment.

Hereinafter, a method for producing a solid electrolyte according to the second embodiment will be described with reference to FIG. 2, but the explanation will focus on the differences from the embodiments described above, and the explanation of similar matters will be omitted.

As shown in FIG. 2, the method for manufacturing the solid electrolyte of the present embodiment includes mixing multiple types of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above composition formula (1), A first mixing step (2A) for obtaining a first mixture P1; and a heating step (2B) for heating the first mixture P1 to form a first electrolyte portion P3 made of a material containing a first electrolyte P3'. , with the second electrolyte P4', in particular, the second electrolyte P4' containing Li, B, and O, in contact with the first electrolyte part P3, the second electrolyte P4' is melted and brought into contact with the first electrolyte part P3. A second electrolyte part forming step (2C) of forming a second electrolyte part P4 is provided.

Thereby, it is possible to provide a method for producing a solid electrolyte that can produce solid electrolyte P100 that can suitably maintain a high total ionic conductivity even in the atmosphere. More specifically, by substituting a part of the lanthanum site of a lanthanum lithium zirconate-based material with Nd and Y, and by substituting a part of the lithium site with Ga, the acid resistance becomes stronger and It is possible to provide a method for producing a solid electrolyte that can suppress the production of lithium carbonate and produce a solid electrolyte P100 that exhibits high total ionic conductivity even in the atmosphere. Further, the effect of increasing the density at low temperatures can be obtained.

The first mixing step (2A) in this embodiment is the same as the first mixing step (1A) in the embodiment described above, and therefore the description thereof will be omitted.

[2-2-1] Heating process The heating process can be performed, for example, in the same manner and under the same conditions as described in [2-1-3] above, but the heating process can be performed in the same manner and under the same conditions as described in [2-1-2] above. After the first heat treatment performed using the same method and conditions as described above, it is preferable to perform the second heat treatment using the same method and conditions as described in [2-1-3] above.
As a result, the same effects as described in the first embodiment can be obtained.

[2-2-2] Second electrolyte part forming step In the second electrolyte part forming step, the second electrolyte P4' is brought into contact with the first electrolyte part P3 formed in the heating step. P4' is melted to form a second electrolyte portion P4 in contact with the first electrolyte portion P3.

The second electrolyte P4' is, for example, LiBH ₄ (melting point 268°C), LiF (melting point 848°C), LiCl (melting point 605°C), LiBr (melting point 552°C), LiI (melting point 469°C), Li ₃ BO ₃ ( oxides, halides, hydrides, borides such as Li _2+x C _1-x B _x O ₃ (0.01<x<0.50) (melting point 680°C to 750°C); Amorphous partially substituted products of , partially crystalline glasses, etc. can be used. Further, a solid solution in which some atoms of the above compound are substituted with other transition metals, typical metals, alkali metals, alkaline rare earths, lanthanides, chalcogenites, halogens, etc. may also be used.
Among these, the second electrolyte P4' preferably has a composition containing Li, B, and O, more preferably has a composition containing Li, B, C, and O, and has the following composition formula: It is more preferable to use the one shown in (2).
Li _2+x C _1-x B _x O ₃ ...(2)
(In formula (2), 0.01<x<0.50 is satisfied.)

Thereby, it becomes easier to form the amorphous second electrolyte portion P4, and the lithium ion conductivity of the solid electrolyte can be further improved.

In formula (2), it is sufficient to satisfy the condition 0.01<x<0.50, but it is preferable to satisfy the condition 0.02≦x≦0.45, and 0.05≦x≦0.40. It is more preferable that the conditions are satisfied.
Thereby, the above-mentioned effects are more prominently exhibited.

The heating temperature in this step depends on the composition of the second electrolyte P4', but is preferably 800°C or more and 1000°C or less, more preferably 800°C or more and 950°C or less, and 800°C or more and 900°C or less. It is more preferable that it is as follows.

In addition, the heating time in this step, especially the heating time at a heating temperature of 800°C or more and 1000°C or less, is not particularly limited, but is preferably 5 minutes or more and 600 minutes or less, and 10 minutes or more and 540 minutes or less. More preferably, the duration is 15 minutes or more and 500 minutes or less.

[3] Composite Next, the composite according to the present invention will be explained.
The composite according to the present invention includes an active material and a solid electrolyte of the present invention that covers a part of the surface of the active material.

Thereby, it is possible to provide a composite that can suitably maintain high total ionic conductivity even under the atmosphere. Furthermore, a composite having sufficiently low grain boundary resistance between the active material and the solid electrolyte can be provided. Such a composite can be suitably applied to a positive electrode composite material or a negative electrode composite material of a battery as described below. As a result, the characteristics and reliability of the battery as a whole can be improved.

In the composite, the solid electrolyte is present, for example, so as to fill in between the particles of the active material, or in contact with, particularly in close contact with, the surface of the particles of the active material.

Examples of the active material constituting the composite according to the present invention include a positive electrode active material and a negative electrode active material.
As the positive electrode active material, for example, an oxide containing Li and O, more specifically, any one containing at least Li and selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, and Cu. A lithium double oxide composed of more than one element can be used. Examples of such multiple oxides include LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , Li ₂ Mn ₂ O ₃ , NMC (Li _p ( _Nix Mn _1-x-y Co _y )O ₂ ), LiCr _0.5 Mn _0.5 O ₂ , LiFePO ₄ , Li ₂ FeP ₂ O ₇ , LiMnPO ₄ , LiFeBO ₃ , Li ₃ V ₂ (PO ₄ ) ₃ , Li ₂ CuO ₂ , Li ₂ FeSiO ₄ , Li ₂ MnSiO ₄ etc. In addition, examples of positive electrode active materials include fluorides such as LiFeF ₃ , boronide complex compounds such as LiBH ₄ and Li ₄ BN ₃ H ₁₀ , iodine complex compounds such as polyvinylpyridine-iodine complex, and nonmetallic compounds such as sulfur. etc. can also be used.

In addition, examples of negative electrode active materials include Nb ₂ O ₅ , V ₂ O ₅ , TiO ₂ , In ₂ O ₃ , ZnO, SnO ₂ , NiO, ITO, AZO, GZO, ATO, FTO, Li ₄ Ti ₅ O Examples include lithium double oxides such as ₁₂ and Li ₂ Ti ₃ O ₇ . Also, for example, metals and alloys such as Li, Al, Si, Si-Mn, Si-Co, Si-Ni, Sn, Zn, Sb, Bi, In, Au, carbon materials, LiC ₂₄ , LiC ₆ , etc. Examples include materials in which lithium ions are inserted between layers of a carbon material.

Further, a coating layer may be formed on the surface of the active material, for example, for the purpose of reducing interfacial resistance with the solid electrolyte, improving electronic conductivity, and the like. For example, by forming a thin film of LiNbO ₃ , Al ₂ O ₃ , ZrO ₂ , Ta ₂ O ₅ or the like on the surface of particles of a positive electrode active material made of LiCoO ₂ , the interfacial resistance for lithium ion conduction can be further reduced. I can do it. The thickness of the coating layer is not particularly limited, but is preferably 3 nm or more and 1 μm or less.

The average particle size of the active material is not particularly limited, but is preferably 0.1 μm or more and 150 μm or less, more preferably 0.3 μm or more and 60 μm or less.

This makes it easier to achieve both an actual capacity density close to the theoretical capacity of the active material and a high charge/discharge rate.

In this specification, the average particle size refers to the average particle size on a volume basis. For example, a sample is added to methanol and dispersed for 3 minutes using an ultrasonic disperser. (Model TA-II manufactured by COULTER ELECTRONICS INS) using a 50 μm aperture.

The particle size distribution of the active material is not particularly limited, and for example, in a particle size distribution having one peak, the half width of the peak can be 0.1 μm or more and 19 μm or less. Furthermore, the active material may have two or more peaks in its particle size distribution.

The active material may be of any shape, for example, spherical, columnar, plate-like, scale-like, hollow, amorphous, etc., and two types of these may be used. The above may be mixed.

When the content of the active material in the composite is XA [mass%] and the content of the solid electrolyte in the composite is XS [mass%], the relationship of 0.1≦XS/XA≦8.3 is satisfied. It is preferable to satisfy the relationship 0.3≦XS/XA≦4.1, and even more preferably to satisfy the relationship 0.6≦XS/XA≦2.1.

In addition to the active material and the solid electrolyte, the composite may also contain, for example, a conductive additive, a binder, and the like.

However, the content of components other than the active material and solid electrolyte in the composite is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. .

Any conductive agent may be used as long as it is a conductor whose electrochemical interaction can be ignored at the electrode reaction potential, and more specifically, for example, acetylene black, Ketjen black, carbon nanotube, etc. Carbon materials such as, noble metals such as palladium and platinum, conductive oxides such as SnO ₂ , ZnO, RuO ₂ , ReO ₃ and Ir ₂ O ₃ can be used.

The composite according to the present invention can be suitably produced, for example, by applying the solid electrolyte production method described in [2] above.

[4] Battery Next, the battery of the present invention will be explained.
The battery of the present invention comprises a composite including the solid electrolyte and active material according to the present invention as described above, an electrode provided on one surface of the composite, and an electrode provided on the other surface of the composite. A current collector.
Thereby, it is possible to provide a battery including a solid electrolyte that can suitably maintain high total ionic conductivity even in the atmosphere.

FIG. 3 is a schematic perspective view schematically showing the configuration of a lithium ion battery as a battery of a preferred embodiment.

As shown in FIG. 3, the lithium ion battery 100 of the present embodiment includes a composite 10 functioning as a positive electrode, a negative electrode 30 provided in contact with one surface of the composite 10, and a negative electrode 30 of the composite 10. A current collector 41 is provided in contact with a surface opposite to the surface in contact with the composite 10, and a current collector 42 is provided in contact with the surface of the negative electrode 30 opposite to the surface in contact with the composite 10. have. In other words, the lithium ion battery 100 of this embodiment has a configuration in which the current collector 41, the composite 10, the negative electrode 30, and the current collector 42 are stacked in this order.

The shape of the lithium ion battery 100 is not particularly limited, and may be, for example, a polygonal disc shape, but in the illustrated configuration, it is a disc shape. The size of the lithium ion battery 100 is not particularly limited, but for example, the diameter of the lithium ion battery 100 is, for example, 10 mm or more and 20 mm or less, and the thickness of the lithium ion battery 100 is, for example, 0.1 mm or more and 1.0 mm or more. It is 0 mm or less.

The fact that the lithium ion battery 100 is small and thin in this way, combined with the fact that it is chargeable and dischargeable and is completely solid, can be suitably used as a power source for a mobile information terminal such as a smartphone. Note that, as will be described later, the lithium ion battery 100 may be used for purposes other than as a power source for a mobile information terminal.

[4-1] Composite The composite 10 includes a positive electrode active material and the solid electrolyte of the present invention described above. In other words, the composite 10 includes an active material part P5 made of a positive electrode active material, which is a type of active material, and a first electrolyte part P3 made of a first electrolyte P3'.
In particular, it is preferable that the composite 10 satisfies the conditions described in [3] above.

The active material constituting the composite 10, that is, the positive electrode active material in this embodiment, is preferably a positive electrode active material containing Li and O.
This makes it possible to serve as a lithium ion supply source and to release and receive lithium ions.

Examples of the positive electrode active material contained in the composite 10 include those exemplified in [3] above.

The composite 10 may contain the positive electrode active material and the solid electrolyte of the present invention described above, that is, the solid electrolyte represented by the composition formula (1) above, but it may further contain another solid electrolyte. Good too.

Examples of such a solid electrolyte include a second electrolyte containing Li, B, and O.
Such a second electrolyte preferably satisfies the conditions described in [2-2-2] above.

The thickness of the composite body 10 is not particularly limited, but is preferably 0.1 μm or more and 500 μm or less, more preferably 0.3 μm or more and 100 μm or less.

[4-2] Negative electrode The negative electrode 30 is composed of a so-called negative electrode active material that repeats electrochemical intercalation and desorption of lithium ions at a lower potential than the material selected as the positive electrode active material constituting the composite 10. It can be anything.

The negative electrode 30 is made of a material containing a negative electrode active material.
As the negative electrode active material constituting the negative electrode 30, for example, those exemplified in [3] above can be used.

In particular, the negative electrode 30, which is an electrode, is preferably made of metal Li.
This results in the ability to store approximately 10 times more electricity per weight and several times more per volume than carbon negative electrodes widely used in lithium ion batteries.

The thickness of the negative electrode 30 is not particularly limited, but is preferably 0.1 μm or more and 500 μm or less, more preferably 0.3 μm or more and 100 μm or less.

Examples of methods for forming the negative electrode 30 include vapor deposition methods such as vacuum evaporation, sputtering, CVD, PLD, ALD, and aerosol deposition, and chemical deposition methods using solutions such as sol-gel and MOD methods. etc. Alternatively, for example, fine particles of the negative electrode active material may be slurried together with a suitable binder, a coating film may be formed by squeegee printing or screen printing, and the coating film may be dried and fired to be baked onto the surface of the composite 10.

[4-3] Current collector The current collectors 41 and 42 are conductors provided to transfer electrons to and from the composite 10 as a positive electrode or the negative electrode 30. The current collectors 41 and 42 are usually made of a material that has sufficiently low electrical resistance and whose electrical conductivity properties and mechanical structure do not substantially change due to charging and discharging.

The constituent material of the current collectors 41 and 42 is, for example, one selected from the group consisting of Cu, Mg, Ti, Fe, Co, Ni, Zn, Al, Ge, In, Au, Pt, Ag, and Pd. metals, and alloys containing two or more metals selected from this group.
In particular, Cu is preferable as the constituent material of the current collectors 41 and 42.

The current collectors 41 and 42 are usually provided so that the contact resistance with the composite body 10 and the negative electrode 30 is reduced, respectively. Examples of the shape of the current collectors 41 and 42 include a plate shape and a mesh shape.

Although the thickness of the current collectors 41 and 42 is not particularly limited, it is preferably 7 μm or more and 85 μm or less, and more preferably 10 μm or more and 60 μm or less.

Note that the lithium ion battery 100 does not necessarily need to include the pair of current collectors 41 and 42, and only needs to include one of the pair of current collectors 41 and 42.

For example, when a plurality of lithium ion batteries 100 are stacked and used so as to be electrically connected in series, the lithium ion battery 100 may be configured to include only the current collector 41 of the pair of current collectors 41 and 42. Good too.

[5] Method for manufacturing a battery Next, a method for manufacturing a battery according to the present invention will be described.
[5-1] Method for manufacturing a battery according to the first embodiment Hereinafter, a method for manufacturing a battery according to the first embodiment will be described.

FIG. 4 is a flowchart showing a method for manufacturing a battery according to the first embodiment, and FIGS. 5 and 6 are vertical cross-sectional views schematically showing a method for manufacturing a battery according to the first embodiment.

As shown in FIGS. 4 to 6, the method for manufacturing a battery according to the present embodiment uses multiple types of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above composition formula (1) in a solvent. A first mixing step (3A) of dissolving and mixing to obtain a first mixture P1, a first molded body forming step (3B) of forming a first molded body Q1 using an active material, and a first molded body forming step (3B) of forming a first molded body Q1 using an active material; Composite 10 including a first electrolyte part P3 made of a crystalline first electrolyte P3' and an active material part P5 made of an active material by heat-treating the first molded body Q1 impregnated with the crystalline first electrolyte P3'. a composite formation step (3C) in which a negative electrode 30 is formed on one side of the composite 10, an electrode formation step (3D) in which a negative electrode 30 as an electrode is formed on one side of the composite 10, and a current collector 41 is formed on the other side of the composite 10. A current collector forming step (3E) is provided.

Thereby, it is possible to provide a method for manufacturing a battery including a solid electrolyte that can suitably maintain high total ionic conductivity even in the atmosphere.

[5-1-1] First mixing step In the first mixing step, multiple types of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above composition formula (1) are dissolved in a solvent, Mix to obtain a first mixture P1.

This step is preferably carried out in the same manner and under the same conditions as described in [2-1-1] above.
However, in this embodiment, a solvent is used to prepare the first mixture P1 in the first mixing step.

[5-1-2] First molded body forming step In the first molded body forming step, the first molded body Q1 is formed using an active material.
The method for forming the first molded body Q1 is not particularly limited, and examples include powder molding.
For forming the first molded body Q1, for example, the active materials exemplified in [3] above, particularly the positive electrode active materials, can be suitably used.

[5-1-3] Complex formation step In the complex formation step, the first mixture P1 is impregnated into the first molded body Q1 and heat-treated to form the crystalline first electrolyte part P3 and the active part. A composite body 10 including the material part P5 is formed.

As a method for impregnating the first molded body Q1 with the first mixture P1, for example, a dipping method can be suitably employed.

The heat treatment in this step can be performed, for example, in the same manner and under the same conditions as described in [2-1-3] above; After the first heat treatment performed using the same method and conditions, it is preferable to perform the second heat treatment using the same method and conditions as described in [2-1-3] above.

More specifically, the heat treatment in this step is performed after the first heat treatment at a heating temperature of 500°C or higher and 650°C or lower, and after the first heat treatment, and the heat treatment at a heating temperature of 800°C or higher and 1000°C or lower. It is preferable to include a second heat treatment.
This provides the same effect as described above.

[5-1-4] Electrode Formation Step In the electrode formation step, the negative electrode 30, which is an electrode, is formed on one side of the composite 10.
The method for forming the negative electrode 30 is not particularly limited, and examples thereof include a vapor phase film forming method using a vacuum evaporation device or the like.

[5-1-5] Current collector forming step In the current collector forming step, a current collector is formed on the other side of the composite 10, that is, on the side of the composite 10 opposite to the surface on which the negative electrode 30 is provided. Form 41.
Further, in this embodiment, the current collector 41 is formed on the other side of the composite 10, and the current collector 42 is formed on the side of the negative electrode 30 opposite to the surface that contacts the composite 10.

The current collectors 41 and 42 are formed, for example, by pressing and bonding metal foils such as aluminum foil or copper foil into a circular shape by die-cutting or the like to the target portion of the composite 10 or the negative electrode, respectively. be able to.

[5-2] Method for manufacturing a battery according to the second embodiment Next, a method for manufacturing a battery according to the second embodiment will be described.

FIG. 7 is a flowchart showing a method for manufacturing a battery according to the second embodiment, and FIGS. 8 and 9 are vertical cross-sectional views schematically showing a method for manufacturing a battery according to the second embodiment.

Hereinafter, a method for manufacturing a battery according to the second embodiment will be explained with reference to these figures, but the explanation will focus on the differences from the embodiments described above, and the explanation of similar matters will be omitted.

As shown in FIGS. 7 to 9, the method for manufacturing a battery according to the present embodiment uses a plurality of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above composition formula (1) in a solvent. A first mixing step (4A) of dissolving and mixing to obtain the first mixture P1, a first molded body forming step (4B) of forming the first molded body Q1 using the active material, and a first molded body forming step (4B) of forming the first molded body Q1 using the active material; A second molding that includes a first electrolyte part P3 made of a crystalline first electrolyte P3' and an active material part P5 made of an active material by applying heat treatment to the first molded body Q1 impregnated with the crystalline first electrolyte P3'. A second molded body forming step (4C) in which a body Q3 is formed, and a second molded body Q3 is brought into contact with a second electrolyte P4', in particular, a second electrolyte P4' containing Li, B, and O. 2 electrolyte P4' is melted and the second molded body Q3 is filled with the melt of the second electrolyte P4', and then the second molded body Q3 filled with the melt of the second electrolyte P4' is cooled. , a composite formation step (4D) of forming a composite 10 including a second electrolyte part P4 and an active material part P5, each of which is composed of a first electrolyte part P3 and a second electrolyte P4', and one side of the composite 10. The present invention includes an electrode forming step (4E) in which a negative electrode 30 is formed as an electrode, and a current collector forming step (4F) in which a current collector 41 is formed on the other side of the composite 10.

Thereby, it is possible to provide a method for manufacturing a battery including a solid electrolyte that can suitably maintain high total ionic conductivity even in the atmosphere.

[5-2-1] First mixing step In the first mixing step, multiple types of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above composition formula (1) are dissolved in a solvent, Mix to obtain a first mixture P1.
This step can be carried out in the same manner and under the same conditions as described in [5-1-1] above.

[5-2-2] First molded body forming step In the first molded body forming step, the first molded body Q1 is formed using an active material.
This step can be carried out in the same manner and under the same conditions as described in [5-1-2] above.

[5-2-3] Second molded body forming step In the second molded body forming step, the first molded body Q1 is impregnated with the first mixture P1 and heat-treated to form the crystalline first electrolyte P3'. A second molded body Q3 is formed, which includes a first electrolyte portion P3 made up of: and an active material portion P5 made of an active material.
This step can be carried out in the same manner and under the same conditions as described in [5-1-3] above.

[5-2-4] Complex forming step In the complex forming step, the second electrolyte P4' is melted while the second electrolyte P4' is in contact with the second compact Q3, and the second compact Q3 is melted. is filled with the melt of the second electrolyte P4', and then the second molded body Q3 filled with the melt of the second electrolyte P4' is cooled to separate the first electrolyte part P3, the second electrolyte part P4 and the active part. A composite body 10 including a substance portion P5 is formed.
This step can be carried out in the same manner and under the same conditions as described in [2-2-2] above.

[5-2-5] Electrode Formation Step In the electrode formation step, the negative electrode 30, which is an electrode, is formed on one side of the composite 10.
This step can be carried out in the same manner and under the same conditions as described in [5-1-4] above.

[5-2-6] Current collector forming step In the current collector forming step, a current collector is formed on the other side of the composite 10, that is, on the side of the composite 10 opposite to the surface on which the negative electrode 30 is provided. Form 41.
Further, in this embodiment, the current collector 41 is formed on the other side of the composite 10, and the current collector 42 is formed on the side of the negative electrode 30 opposite to the surface that contacts the composite 10.
This step can be carried out in the same manner and under the same conditions as described in [5-1-5] above.

[5-3] Method for manufacturing a battery according to the third embodiment Next, a method for manufacturing a battery according to the third embodiment will be described.

FIG. 10 is a flowchart showing a method for manufacturing a battery according to the third embodiment, and FIGS. 11, 12, and 13 are vertical cross-sectional views schematically showing a method for manufacturing a battery according to the third embodiment. It is.

Hereinafter, a method for manufacturing a battery according to the third embodiment will be explained with reference to these figures, but the explanation will focus on the differences from the embodiments described above, and the explanation of similar matters will be omitted.

As shown in FIGS. 10 to 13, the method for manufacturing the battery of this embodiment mixes multiple types of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above compositional formula (1). a first mixing step (5A) in which a first mixture P1 is obtained; a pre-fired body forming step (5B) in which a first heat treatment is performed on the first mixture P1 to obtain a pre-fired body P2; a second mixing step (5C) in which the second mixture Q6 is obtained by mixing the second mixture Q6; a third molded body forming step (5D) in which the second mixture Q6 is molded to form a third molded body Q7; a composite forming step (5E) of subjecting the compact Q7 to a second heat treatment to form a composite 10 including a crystalline first electrolyte portion P3 and an active material portion P5 made of an active material; It includes an electrode forming step (5F) of forming a negative electrode 30 as an electrode on one side of the body 10, and a current collector forming step (5G) of forming a current collector 41 on the other side of the composite body 10. .

Thereby, it is possible to provide a method for manufacturing a battery including a solid electrolyte that can suitably maintain high total ionic conductivity even in the atmosphere.

[5-3-1] First mixing step In the first mixing step, multiple types of raw materials containing the metal elements constituting the lithium composite metal oxide represented by the above composition formula (1) are mixed to form the first mixture. A mixture P1 is obtained.
This step can be carried out in the same manner and under the same conditions as described in [5-1-1] above.
However, in this embodiment, it is preferable that no solvent be used in this step.

[5-3-2] Temporarily fired body forming step In the temporarily fired body forming step, the first mixture P1 is subjected to a first heat treatment to obtain a temporarily fired body P2.
This step can be performed in the same manner and under the same conditions as described in [2-1-2] above.

In particular, the heating temperature in the first heat treatment is preferably 500°C or more and 650°C or less, more preferably 510°C or more and 650°C or less, and even more preferably 520°C or more and 600°C or less.

As a result, it is possible to more effectively prevent the metal elements that should constitute the first electrolyte portion P3 from being involuntarily vaporized, and in particular, the vaporization of Li, which is easily volatile in metal materials, and the like. The composition of one electrolyte portion P3 can be controlled more strictly, and the lithium ion battery 100 can be manufactured more efficiently.

[5-3-3] Second Mixing Step In the second mixing step, the pre-fired body P2 and the active material are mixed to obtain a second mixture Q6.

This process is the same as described in [2-1-1] above, except that the pre-fired body P2 and the active material are used instead of the plurality of raw materials containing the metal elements contained in the composition formula (1) above. It can be carried out in the same manner and under the same conditions.

[5-3-4] Third molded body forming step In the third molded body forming step, the second mixture Q6 is molded to form a third molded body Q7.

This step can be carried out in the same manner and under the same conditions as described in [5-1-2] above, except that the second mixture Q6 is used instead of the active material.

[5-3-5] Complex formation step In the complex formation step, the third molded body Q7 is subjected to a second heat treatment to form a complex 10 including the first electrolyte portion P3 and the active material portion P5. .

This step is preferably carried out using the same method and conditions as described in [2-1-3] above, for example.
This provides the same effect as described above.

In particular, the heating temperature in the second heat treatment is preferably 800°C or more and 1000°C or less, more preferably 800°C or more and 950°C or less, and even more preferably 800°C or more and 900°C or less.

Thereby, the first electrolyte portion P3 having desired characteristics can be stably formed by heat treatment at a relatively low temperature and in a relatively short time. In addition, since the first electrolyte portion P3 can be formed by heat treatment at a relatively low temperature and in a relatively short time, for example, the productivity of the lithium ion battery 100 can be improved, and from the viewpoint of energy saving. It is also preferable.

[5-3-6] Electrode Formation Step In the electrode formation step, the negative electrode 30, which is an electrode, is formed on one side of the composite 10.
This step can be carried out in the same manner and under the same conditions as described in [5-1-4] above.

[5-3-7] Current collector forming step In the current collector forming step, a current collector is formed on the other side of the composite 10, that is, on the side of the composite 10 opposite to the surface on which the negative electrode 30 is provided. Form 41.
Further, in this embodiment, the current collector 41 is formed on the other side of the composite 10, and the current collector 42 is formed on the side of the negative electrode 30 opposite to the surface that contacts the composite 10.
This step can be carried out in the same manner and under the same conditions as described in [5-1-5] above.

[5-4] Method for manufacturing a battery according to the fourth embodiment Next, a method for manufacturing a battery according to the fourth embodiment will be described.

FIG. 14 is a flowchart showing a method for manufacturing a battery according to the fourth embodiment, and FIGS. 15, 16, and 17 are vertical cross-sectional views schematically showing a method for manufacturing a battery according to the fourth embodiment. It is.

Hereinafter, a method for manufacturing a battery according to the fourth embodiment will be described with reference to these figures, but the explanation will focus on the differences from the embodiments described above, and the explanation of similar matters will be omitted.

As shown in FIGS. 14 to 17, the method for manufacturing the battery of this embodiment involves mixing multiple types of raw materials containing metal elements constituting the lithium composite metal oxide represented by the above compositional formula (1). a first mixing step (6A) in which a first mixture P1 is obtained; a pre-fired body forming step (6B) in which a first heat treatment is performed on the first mixture P1 to obtain a pre-fired body P2; a second mixing step (6C) in which the second mixture Q6 is obtained by mixing the mixture with a substance; a third molded body forming step (6D) in which the second mixture Q6 is molded to form a third molded body Q7; A second heat treatment is performed on the molded body Q7 to form a second molded body Q3 including a first electrolyte portion P3 made of a crystalline first electrolyte P3′ and an active material portion P5 made of an active material. A second molded body forming step (6E) in which a second electrolyte P4', particularly a second electrolyte P4' containing Li, B, and O, is brought into contact with the second molded body Q3. The second molded body Q3 is filled with the melt of the second electrolyte P4', and then the second molded body Q3 filled with the melt of the second electrolyte P4' is cooled and the second molded body Q3 is filled with the melt of the second electrolyte P4'. A composite forming step (6F) of forming a composite 10 including a second electrolyte part P4 and an active material part P5, which are composed of a part P3 and a second electrolyte P4', and an electrode on one side of the composite 10. The method includes an electrode forming step (6G) in which the negative electrode 30 is formed, and a current collector forming step (6H) in which the current collector 41 is formed on the other side of the composite 10.

Thereby, it is possible to provide a method for manufacturing a battery including a solid electrolyte that can suitably maintain high total ionic conductivity even in the atmosphere.

[5-4-1] First mixing step In the first mixing step, multiple types of raw materials containing the metal elements constituting the lithium composite metal oxide represented by the above composition formula (1) are mixed to form the first mixture. A mixture P1 is obtained.
This step can be carried out in the same manner and under the same conditions as described in [5-3-1] above.
However, in this embodiment, it is preferable that no solvent be used in this step.

[5-4-2] Temporarily fired body forming step In the temporarily fired body forming step, the first mixture P1 is subjected to a first heat treatment to obtain a temporarily fired body P2.
This step can be carried out in the same manner and under the same conditions as described in [5-3-2] above.

[5-4-3] Second Mixing Step In the second mixing step, the pre-fired body P2 and the active material are mixed to obtain a second mixture Q6.
This step can be carried out in the same manner and under the same conditions as described in [5-3-3] above.

[5-4-4] Third molded body forming step In the third molded body forming step, the second mixture Q6 is molded to form a third molded body Q7.
This step can be performed in the same manner and under the same conditions as described in [5-3-4] above.

[5-4-5] Second compact forming step In the second compact forming step, the third compact Q7 is subjected to a second heat treatment to form a second compact including the first electrolyte portion P3 and the active material portion P5. A molded body Q3 is formed.
This step can be carried out in the same manner and under the same conditions as described in [5-3-5] above.

[5-4-6] Complex formation step In the complex formation step, the second electrolyte P4' is melted while the second electrolyte P4' is in contact with the second compact Q3, and the second electrolyte P4' is melted to form the second compact Q3. is filled with the melt of the second electrolyte P4', and then the second molded body Q3 filled with the melt of the second electrolyte P4' is cooled to separate the first electrolyte part P3, the second electrolyte part P4 and the active part. A composite body 10 including a substance portion P5 is formed.
This step can be performed in the same manner and under the same conditions as described in [5-2-4] above.

[5-4-7] Electrode Formation Step In the electrode formation step, the negative electrode 30, which is an electrode, is formed on one side of the composite 10.
This step can be carried out in the same manner and under the same conditions as described in [5-1-4] above.

[5-4-8] Current collector forming step In the current collector forming step, a current collector is formed on the other side of the composite 10, that is, on the side of the composite 10 opposite to the surface on which the negative electrode 30 is provided. Form 41.
Further, in this embodiment, the current collector 41 is formed on the other side of the composite 10, and the current collector 42 is formed on the side of the negative electrode 30 opposite to the surface that contacts the composite 10.
This step can be carried out in the same manner and under the same conditions as described in [5-1-5] above.

[6] Electronic device Next, the electronic device of the present invention will be explained.

The electronic device of the present invention includes the battery of the present invention described above.
Thereby, it is possible to provide an electronic device including a battery including a solid electrolyte that can suitably maintain high total ionic conductivity even in the atmosphere.

Examples of electronic devices include personal computers, digital cameras, mobile phones, smartphones, music players, tablet devices, watches, smart watches, various printers such as inkjet printers, televisions, projectors, head-up displays, wireless headphones, wireless earphones, Smart glasses, wearable devices such as head-mounted displays, video cameras, video tape recorders, car navigation devices, drive recorders, pagers, electronic notebooks, electronic dictionaries, electronic translators, calculators, electronic game devices, toys, word processors, workstations, Robots, videophones, security TV monitors, electronic binoculars, POS terminals, medical equipment, fish finders, various measuring instruments, equipment for mobile terminal base stations, various instruments for vehicles, railway vehicles, aircraft, helicopters, ships, etc. , flight simulators, network servers, etc. Further, the lithium ion battery 100 may be applied to a moving object such as a car or a ship, for example. More specifically, it can be suitably applied, for example, as a storage battery for electric vehicles, plug-in hybrid vehicles, hybrid vehicles, fuel cell vehicles, and the like. Further, it can also be applied to, for example, household power sources, industrial power sources, storage batteries for solar power generation, and the like.

Hereinafter, a wearable device will be described as a specific example of the electronic device of the present invention.
FIG. 18 is a perspective view showing the configuration of a wearable device as an electronic device.

As shown in FIG. 18, a wearable device 300 as an electronic device is an information device that is worn on a human body, for example, a wrist WR like a wristwatch, and can obtain information about the human body, and includes a band 301 and a sensor 302. , a display section 303, a processing section 304, and a lithium ion battery 100.

The band 301 is in the form of a band made of flexible resin such as rubber so as to tightly fit on the wrist WR when worn, and has a connecting part at the end of the band whose connecting position can be adjusted. .

The sensor 302 is, for example, an optical sensor, and is arranged on the inner surface side of the band 301, that is, on the wrist WR side, so as to touch the wrist WR when worn.

The display unit 303 is, for example, a light-receiving type liquid crystal display device, and is placed on the outside of the band 301, that is, opposite to the inside where the sensor 302 is attached, so that the wearer can read the information displayed on the display unit 303. placed on the side.

The processing section 304 is, for example, an integrated circuit, is built into the band 301, and is electrically connected to the sensor 302 and the display section 303. The processing unit 304 performs calculation processing for measuring pulse, blood sugar level, etc. based on the output from the sensor 302. It also controls the display unit 303 to display measurement results and the like.

The lithium ion battery 100 is removably built into the band 301 as a power supply source that supplies power to the sensor 302, display section 303, processing section 304, and the like.

According to the wearable device 300 of the present embodiment, the sensor 302 electrically detects information related to the wearer's pulse and blood sugar level from the wrist WR, and after the information is processed by the processing unit 304, the display unit 303 It is possible to display pulse rate, blood sugar level, etc. The display unit 303 can display not only the measurement results but also, for example, information indicating the state of the human body predicted from the measurement results, the time, and the like.

Furthermore, since the lithium ion battery 100 is small but has excellent charging and discharging characteristics, the wearable device 300 is lightweight and thin and can withstand repeated use over a long period of time. be able to. In addition, since the lithium ion battery 100 is a solid-state secondary battery, it can be used repeatedly by charging, and there is no fear of electrolyte leaking, so it is possible to provide the wearable device 300 that can be used safely for a long period of time. .

In this embodiment, the wristwatch-type wearable device 300 is illustrated, but the wearable device 300 may be worn on the ankle, head, ear, waist, etc., for example.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto.

For example, the solid electrolyte manufacturing method and the battery manufacturing method may include other steps in addition to the steps described above. For example, the order of the steps may be changed.

Further, the battery of the present invention is not limited to those of the embodiments described above, as long as it includes the solid electrolyte of the present invention.

For example, the battery according to the embodiment described above includes a composite including the solid electrolyte and active material of the present invention, an electrode provided on one surface of the composite, and an electrode provided on the other surface of the composite. Although the present invention includes a current collector, a solid electrolyte layer containing no active material may be provided between the composite and the electrode.

Furthermore, in the above-described embodiments, the case where the composite that constitutes the battery includes a positive electrode active material as an active material and the electrode is a negative electrode has been representatively described, but the composite that constitutes the battery is an active material. The material includes a negative electrode active material, and the electrode may be a positive electrode.

Next, specific examples of the present invention will be described. In addition, in the following description, room temperature refers to 25° C. and 1 atm. Further, treatments and measurements that do not specifically indicate temperature conditions were conducted at 25° C., and treatments and measurements that did not specifically indicate pressure conditions were conducted in an environment of 1 atmosphere.

[7] Production of solid electrolyte First, pre-fired bodies used for production of solid electrolytes in Examples A1 to A5 and Comparative Examples A1 to A7, which will be described later, were produced.
A solution of the metal compound described below was used to prepare each calcined body.

[7-1] Preparation of a solution of a metal compound used in the production of a calcined body [7-1-1] Preparation of a 2-n-n-butoxyethanol solution of lithium nitrate Company trademark. Pyrex is a registered trademark.) 1.3789 g of 3N5 99.95% purity lithium nitrate manufactured by Kanto Kagaku Co., Ltd. was added to a reagent bottle manufactured by Kanto Kagaku Co. 18.6211 g of glycol monobutyl ether) was weighed. Next, the reagent bottle was placed on a hot plate with a magnetic stirrer function, and while stirring at 170°C for 1 hour, lithium nitrate was completely dissolved in 2-n-n-butoxyethanol, slowly cooled to room temperature, and dissolved at 1 mol/kg. A 2-n-n-butoxyethanol solution of lithium nitrate at a certain concentration was obtained.

[7-1-2] Preparation of 2-n-n-butoxy ethanol solution of lanthanum nitrate Add 8.6608 g of 4N lanthanum nitrate hexahydrate manufactured by Kanto Kagaku Co., Ltd. to a 30 g Pyrex reagent bottle containing a magnetic stirrer. and 11.3392 g of Deka special grade 2-n-n-butoxyethanol manufactured by Kanto Kagaku Co., Ltd. were weighed. Next, the reagent bottle was placed on a hot plate with a magnetic stirrer function, and lanthanum nitrate hexahydrate was completely dissolved in 2-n-butoxyethanol while stirring at 140°C for 30 minutes, and slowly cooled to room temperature. A 2-n-n-butoxyethanol solution of lanthanum nitrate with a concentration of 1 mol/kg was obtained.

[7-1-3] Preparation of ethyl alcohol solution of yttrium nitrate Into a 30 g Pyrex reagent bottle containing a magnetic stirrer, add 3.8301 g of 3N yttrium nitrate hexahydrate manufactured by Kojundo Kagaku Kenkyusho Co., Ltd. and 6.1699 g of EL grade ethyl alcohol manufactured by Kanto Kagaku Co., Ltd. were weighed. Next, the reagent bottle was placed on a hot plate with a magnetic stirrer function, and while stirring at 75°C for 30 minutes, yttrium nitrate hexahydrate was completely dissolved in ethyl alcohol, slowly cooled to room temperature, and 1 mol. An ethyl alcohol solution of yttrium nitrate with a concentration of /kg was obtained.

[7-1-4] Preparation of 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide Add 3.8368 g of zirconium tetra-n-butoxide manufactured by Kojundo Kagaku Kenkyusho into a 20 g Pyrex reagent bottle containing a magnetic stirrer. and 6.1632 g of deer special grade 2-n-n-butoxyethanol manufactured by Kanto Kagaku Co., Ltd. were weighed. Next, the reagent bottle was placed on a hot plate with a magnetic stirrer function, and while stirring at room temperature for 30 minutes, zirconium tetranormal butoxide was completely dissolved in 2-normal butoxyethanol, and zirconium tetranormal butoxide was dissolved at a concentration of 1 mol/kg. A 2-n-n-butoxyethanol solution of butoxide was obtained.

[7-1-5] Preparation of ethyl alcohol solution of gallium nitrate Gallium nitrate n-hydrate (n=5. 5) 3.5470 g and 6.4530 g of ethyl alcohol that had been previously dehydrated were weighed. Next, the reagent bottle was placed on a hot plate with a magnetic stirrer function, and while stirring at 90°C for 1 hour, gallium nitrate n hydrate (n = 5.5) was completely dissolved in ethyl alcohol, and the mixture was heated to room temperature. By slow cooling, an ethyl alcohol solution of gallium nitrate with a concentration of 1 mol/kg was obtained. Note that the hydration number n of the gallium nitrate n-hydrate used was 5.5 based on the mass reduction results from a combustion experiment (differential thermal analysis).

[7-1-6] Preparation of 2-n-n-butoxy ethanol solution of neodymium nitrate Into a 20 g Pyrex reagent bottle containing a magnetic stirrer, add neodymium nitrate n hydrate (n =5) 4.2034 g and 5.7966 g of 2-n-n-butoxyethanol which had been previously dehydrated were weighed. Next, the reagent bottle was placed on a hot plate with a magnetic stirrer function, and while stirring at 140°C for 30 minutes, neodymium nitrate n-hydrate (n = 5) was completely dissolved in 2-n-butoxyethanol, and the mixture was heated to room temperature. The solution was slowly cooled to 1 mol/kg to obtain a 2-n-n-butoxy ethanol solution of neodymium nitrate at a concentration of 1 mol/kg. Note that the hydration number n of the neodymium nitrate n-hydrate used was 5 based on the mass reduction results from a combustion experiment (differential thermal analysis).

[7-2] Production of pre-fired bodies according to Examples A1 to A5 and Comparative Examples A1 to A7 Using the solutions of each metal compound obtained as described above, Examples A1 to A1 to A7 were produced as follows. Pre-fired bodies according to A5 and Comparative Examples A1 to A7 were manufactured.

(Example A1)
In this example, the temporary solid electrolyte used for manufacturing the solid electrolyte having the composition (Li _5.50 Ga _0.50 ) (La _2.94 Ndr _0.01 Y _0.05 )Zr ₂ O ₁₂ was prepared as follows. A fired body was manufactured.

First, in a Pyrex reagent bottle, 5.500 g of the 2-n-n-butoxyethanol solution of lithium nitrate prepared as described above, 0.500 g of the ethyl alcohol solution of gallium nitrate, and 2.0 g of the 2-n-n-butoxy ethanol solution of lanthanum nitrate. 940 g of 2-n-butoxyethanol solution of neodymium nitrate, 0.010 g of ethyl alcohol solution of yttrium nitrate, 2 mL of 2-n-butoxy ethanol as an organic solvent, and 1 mL of ethyl alcohol were weighed. A magnetic stirrer was added thereto, and the mixture was placed on a hot plate with a magnetic stirrer function.

The temperature of the hot plate was set at 160° C., the rotation speed was set at 500 rpm, and heating and stirring were performed for 30 minutes.

Next, 2 mL of 2-n-n-butoxyethanol and 1 mL of ethyl alcohol were added, and heating and stirring were performed again for 30 minutes. If heating and stirring for 30 minutes constitutes one dehydration treatment, the dehydration treatment was performed twice in this example.
After the dehydration treatment, the reagent bottle was sealed with a lid.

Next, the set temperature of the hot plate was set to 25° C., the rotation speed was set to 500 rpm, and the mixture was stirred and slowly cooled to room temperature.

Next, the reagent bottle was moved to a dry atmosphere, and 2.000 g of the 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide prepared as described above was weighed into the reagent bottle, and a magnetic stirrer was added.

Next, the rotation speed of the magnetic stirrer was set to 500 rpm, and the mixture was stirred at room temperature for 30 minutes to obtain a precursor solution.

Next, the above precursor solution was placed in a titanium Petri dish with an inner diameter of 50 mm and a height of 20 mm. This was placed on a hot plate, the set temperature of the hot plate was set to 160°C, and the temperature was heated for 1 hour, and then the temperature was set to 180°C for 30 minutes to remove the solvent.

Subsequently, the set temperature of the hot plate was set to 360° C., and the mixture was heated for 30 minutes to decompose most of the organic components contained therein by combustion.

Thereafter, the set temperature of the hot plate was set to 540°C, and the mixture was heated for 1 hour, and further heated to 600°C for 2 hours to burn and decompose the remaining organic components. Then, it was slowly cooled to room temperature on a hot plate to obtain a solid composition as a temporarily fired body.

(Example A2)
As solutions of metal compounds, 5.500 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 0.500 g of an ethyl alcohol solution of gallium nitrate, 2.940 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1, except that 0.040 g of an ethanol solution, 0.020 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this example, the pre-calcination process used for producing the solid electrolyte having the composition (Li _5.5 Ga _0.5 ) (La _2.94 Nd _0.04 Y _0.02 )Zr ₂ O ₁₂ manufactured a body.

(Example A3)
As solutions of metal compounds, 6.700 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 0.100 g of an ethyl alcohol solution of gallium nitrate, 2.800 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1 above, except that 0.050 g of an ethanol solution, 0.150 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this example, the pre-calcination process used for producing the solid electrolyte having the composition (Li _6.7 Ga _0.1 ) (La _2.8 Nd _0.05 Y _0.15 )Zr ₂ O ₁₂ manufactured a body.

(Example A4)
Solutions of metal compounds include 4.000 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 1.000 g of an ethyl alcohol solution of gallium nitrate, 2.880 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1, except that 0.050 g of an ethanol solution, 0.070 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this example, a pre-fired body used for manufacturing a solid electrolyte having the composition (Li ₄ Ga ₁ ) (La _2.88 Nd _0.05 Y _0.07 )Zr ₂ O ₁₂ was manufactured. .

(Example A5)
Solutions of metal compounds include 5.200 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 0.600 g of an ethyl alcohol solution of gallium nitrate, 2.750 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1, except that 0.200 g of an ethanol solution, 0.050 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this example, the pre-calcination process used for producing the solid electrolyte having the composition (Li _5.2 Ga _0.6 ) (La _2.75 Nd _0.2 Y _0.05 )Zr ₂ O ₁₂ manufactured a body.

(Comparative example A1)
As solutions of metal compounds, 5.500 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 0.500 g of an ethyl alcohol solution of gallium nitrate, 2.960 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A solid composition as a calcined body was obtained in the same manner as in Example A1, except that 0.040 g of the ethanol solution and 2.000 g of the 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used.

In this way, in this comparative example, a pre-fired body used for manufacturing a solid electrolyte having the composition (Li _5.5 Ga _0.5 ) (La _2.96 Nd _0.04 )Zr ₂ O ₁₂ was manufactured. .

(Comparative example A2)
As solutions of metal compounds, 5.500 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 0.500 g of an ethyl alcohol solution of gallium nitrate, 2.790 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1, except that 0.040 g of an ethanol solution, 0.170 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this comparative example, the pre-calcination process used for producing the solid electrolyte having the composition (Li _5.5 Ga _0.5 ) (La _2.79 Nd _0.04 Y _0.17 )Zr ₂ O ₁₂ manufactured a body.

(Comparative example A3)
The metal compound solutions include 6.700 g of a 2-n-n-butoxyethanol solution of lithium nitrate, 0.100 g of a gallium nitrate solution in ethyl alcohol, 2.850 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 0.0 g of an ethyl alcohol solution of yttrium nitrate. A solid composition as a pre-fired body was obtained in the same manner as in Example A1 above, except that 150 g of 2-n-n-butoxyethanol solution of zirconium tetra-n-butoxide was used.

In this way, in this comparative example, a pre-fired body used for manufacturing a solid electrolyte having the composition (Li _6.7 Ga _0.1 ) (La _2.85 Y _0.15 )Zr ₂ O ₁₂ was manufactured. .

(Comparative example A4)
As solutions of metal compounds, 6.700 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 0.100 g of an ethyl alcohol solution of gallium nitrate, 2.640 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1, except that 0.210 g of an ethanol solution, 0.150 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this comparative example, the pre-calcination process used for producing the solid electrolyte having the composition (Li _6.7 Ga _0.1 ) (La _2.64 Nd _0.21 Y _0.15 )Zr ₂ O ₁₂ manufactured a body.

(Comparative example A5)
As solutions of metal compounds, 6.850 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 0.050 g of an ethyl alcohol solution of gallium nitrate, 2.880 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1, except that 0.050 g of an ethanol solution, 0.070 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this comparative example, the pre-calcination process used to produce the solid electrolyte having the composition (Li _6.85 Ga _0.05 ) (La _2.88 Nd _0.05 Y _0.07 )Zr ₂ O ₁₂ manufactured a body.

(Comparative example A6)
Solutions of metal compounds include 3.850 g of a 2-n-n-butoxy ethanol solution of lithium nitrate, 1.050 g of an ethyl alcohol solution of gallium nitrate, 2.880 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2-n-butoxy of neodymium nitrate. A pre-fired body was prepared in the same manner as in Example A1, except that 0.050 g of an ethanol solution, 0.070 g of an ethyl alcohol solution of yttrium nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide were used. A solid composition was obtained.

In this way, in this comparative example, the pre-calcination process used for producing the solid electrolyte having the composition (Li _3.85 Ga _1.05 ) (La _2.88 Nd _0.05 Y _0.07 )Zr ₂ O ₁₂ manufactured a body.

(Comparative example A7)
Other than using 7.00 g of a 2-n-n-butoxyethanol solution of lithium nitrate, 3.000 g of a 2-n-n-butoxy ethanol solution of lanthanum nitrate, and 2.000 g of a 2-n-n-butoxy ethanol solution of zirconium tetra-n-butoxide as the solution of the metal compound. A solid composition as a pre-fired body was obtained in the same manner as in Example A1.

In this manner, in this comparative example, a pre-fired body used for producing a solid electrolyte having the composition Li ₇ La ₃ Zr ₂ O ₁₂ was produced.

[7-3] Production of solid electrolyte Solid electrolytes were produced in the following manner using the pre-fired bodies of Examples A1 to A5 and Comparative Examples A1 to A7 obtained as described above.

First, the above calcined body was transferred to an agate mortar and sufficiently ground. Weighed 0.150 g of the pulverized pre-fired body thus obtained, put it into a pellet die with an inner diameter of 10 mm and an exhaust port as a mold, and pressurized it at a pressure of 0.624 kN/mm ² for 5 minutes. A pre-fired pellet, which is a disc-shaped molded product, was produced.

Further, the pre-fired pellets were placed in a magnesium oxide crucible, covered with a magnesium oxide lid, and subjected to main firing in an electric muffle furnace FP311 manufactured by Yamato Scientific Co., Ltd. The main firing conditions were 900° C. for 8 hours. Next, the electric muffle furnace was slowly cooled to room temperature, and a disk-shaped solid electrolyte having a diameter of about 9.5 mm and a thickness of about 600 μm was taken out from the crucible.

The compositions and crystal phases of the solid electrolytes of Examples A1 to A5 and Comparative Examples A1 to A7 are summarized in Table 1. The crystal phase of the solid electrolyte was identified from an X-ray diffraction pattern obtained by measurement using an X-ray diffraction device X'Pert-PRO manufactured by Philips. In Table 1, the tetragonal crystal structure is shown as "t", and the cubic crystal structure is shown as "c". Note that the content of the oxoacid compound in the solid electrolytes of Examples A1 to A5 and Comparative Examples A1 to A7 was all 10 ppm or less. In addition, the pre-fired bodies according to Examples A1 to A5 and Comparative Examples A1 to A7 all had a solvent content of 0.1% by mass or less. In addition, when some of the pre-fired bodies according to Examples A1 to A5 were measured using a TG-DTA at a temperature increase rate of 10°C/min, all exothermic peaks in the range of 300°C or more and 1,000°C or less were found. , only one was observed. From this, it can be said that the pre-fired bodies according to Examples A1 to A5 are substantially composed of a single crystal phase.

[7-4] Evaluation of solid electrolyte [7-4-1] Evaluation of total lithium ion conductivity For the disk-shaped solid electrolytes of Examples A1 to A5 and Comparative Examples A1 to A7 immediately after manufacture, on both sides, A circular metal lithium foil with a diameter of 5 mm was pressed to form an activation electrode.

Then, the electrochemical impedance was measured using an AC impedance analyzer Solatron 1260 (manufactured by Solatron Analtical) to determine the total lithium ion conductivity. Further, for Examples A1 to A5 and Comparative Examples A1 to A7, 24 hours after the solid electrolyte was manufactured, the electrochemical impedance was measured in the same manner as above to determine the total lithium ion conductivity.

Electrochemical impedance measurements were performed at an AC amplitude of 10 mV in the frequency range from 10 ⁷ Hz to 10 ⁻¹ Hz. The total lithium ion conductivity obtained by electrochemical impedance measurement includes the bulk lithium ion conductivity in the solid electrolyte and the lithium ion conductivity at grain boundaries.
These results are summarized in Table 2.

As is clear from Table 2, Examples A1 to A5 containing Ga, Nd, and Y in predetermined proportions all had excellent electrical conductivity immediately after production, and even after being left in the atmosphere for 24 hours. The conductivity was maintained. On the other hand, satisfactory results were not obtained in Comparative Examples A1 to A7.

[8] Production of batteries Two lithium ion batteries each according to Examples B1a to B3b and Comparative Examples B1a to B7b were produced as follows. That is, for each of Examples B1a to B3b and Comparative Examples B1a to B7b, one lithium ion battery was used to evaluate charge and discharge characteristics immediately after manufacture, and one lithium ion battery was used to evaluate charge and discharge characteristics after being left in the atmosphere for 24 hours. One ion battery was manufactured.

(Example B1a)
In [5-1] above, a precursor solution prepared in the same manner as described in Example A1 was used as the first mixture, and LiCoO ₂ powder with an average particle size of 5 μm was used as the positive electrode active material. A lithium ion battery was manufactured according to the method described. Note that the negative electrode was made of metal Li.

(Example B1b)
A precursor solution prepared in the same manner as described in Example A1 above was used as the first mixture, and Li ₃ BO ₃ powder with an average particle size of 5 μm was used as the second electrolyte. A lithium ion battery was manufactured according to the method described in [5-2] above using LiCoO ₂ powder as a positive electrode active material. Note that the negative electrode was made of metal Li.

(Example B1c)
A lithium ion battery was manufactured in the same manner as in Example B1b, except that Li _2.2 C _0.8 B _0.2 O ₃ powder with an average particle size of 7 μm was used as the second electrolyte.

(Example B1d)
The pre-calcined body prepared in the same manner as described in Example A1 above was used as the first mixture, and LiCoO ₂ powder with an average particle size of 5 μm was used as the positive electrode active material, and the process was carried out in [5-3] above. A lithium ion battery was manufactured according to the method described. Note that the negative electrode was made of metal Li.

(Example B1e)
A pre-fired body prepared in the same manner as described in Example A1 was used as the first mixture, and Li ₃ BO ₃ powder with an average particle size of 5 μm was used as the second electrolyte. A lithium ion battery was manufactured according to the method described in [5-4] above using LiCoO ₂ powder as a positive electrode active material. Note that the negative electrode was made of metal Li.

(Example B1f)
A lithium ion battery was manufactured in the same manner as in Example B1e, except that Li _2.2 C _0.8 B _0.2 O ₃ powder with an average particle size of 7 μm was used as the second electrolyte.

(Example B3a)
The pre-calcined body prepared in the same manner as described in Example A3 above was used as the first mixture, and LiCoO ₂ powder with an average particle size of 5 μm was used as the positive electrode active material, and the process was carried out in [5-3] above. A lithium ion battery was manufactured according to the method described. Note that the negative electrode was made of metal Li.

(Example B3b)
A pre-fired body prepared in the same manner as described in Example A3 was used as the first mixture, and Li _2.2 C _0.8 B _0.2 O ₃ powder with an average particle size of 7 μm was used as the second mixture. A lithium ion battery was manufactured according to the method described in [5-4] above, using LiCoO ₂ powder with an average particle size of 5 μm as an electrolyte and as a positive electrode active material. Note that the negative electrode was made of metal Li.

(Comparative example B1a)
In the above [5-3], a pre-fired body prepared in the same manner as described in Comparative Example A1 was used as the first mixture, and LiCoO ₂ powder with an average particle size of 5 μm was used as the positive electrode active material. A lithium ion battery was manufactured according to the method described. Note that the negative electrode was made of metal Li.

(Comparative example B1b)
A pre-fired body prepared in the same manner as described in Comparative Example A1 was used as the first mixture, and Li _2.2 C _0.8 B _0.2 O ₃ powder with an average particle size of 7 μm was used as the second mixture. A lithium ion battery was manufactured according to the method described in [5-4] above, using LiCoO ₂ powder with an average particle size of 5 μm as an electrolyte and as a positive electrode active material. Note that the negative electrode was made of metal Li.

(Comparative example B3a)
The pre-fired body prepared in the same manner as described in Comparative Example A3 was used as the first mixture, and LiCoO ₂ powder with an average particle size of 5 μm was used as the positive electrode active material, and in [5-3] above. A lithium ion battery was manufactured according to the method described. Note that the negative electrode was made of metal Li.

(Comparative example B3b)
A pre-fired body prepared in the same manner as described in Comparative Example A3 was used as the first mixture, and Li _2.2 C _0.8 B _0.2 O ₃ powder with an average particle size of 7 μm was used as the second mixture. A lithium ion battery was manufactured according to the method described in [5-4] above, using LiCoO ₂ powder with an average particle size of 5 μm as an electrolyte and as a positive electrode active material. Note that the negative electrode was made of metal Li.

(Comparative example B7a)
In [5-3] above, a pre-fired body prepared in the same manner as described in Comparative Example A7 was used as the first mixture, and LiCoO ₂ powder with an average particle size of 5 μm was used as the positive electrode active material. A lithium ion battery was manufactured according to the method described. Note that the negative electrode was made of metal Li.

(Comparative example B7b)
A pre-fired body prepared in the same manner as described in Comparative Example A7 was used as the first mixture, and Li _2.2 C _0.8 B _0.2 O ₃ powder with an average particle size of 7 μm was used as the second mixture. A lithium ion battery was manufactured according to the method described in [5-4] above, using LiCoO ₂ powder with an average particle size of 5 μm as an electrolyte and as a positive electrode active material. Note that the negative electrode was made of metal Li.

Table 3 summarizes the main conditions of the lithium ion batteries according to Examples B1a to B3b and Comparative Examples B1a to B7b obtained as described above.

[9] Battery Evaluation Immediately after manufacture, each of the lithium ion batteries of Examples B1a to B3b and Comparative Examples B1a to B7b obtained as described above was tested using a battery charge/discharge evaluation system manufactured by Hokuto Denko Co., Ltd. The battery was connected to HJ1001SD8 and charged and discharged under the conditions shown in Tables 4 and 5, and the charging and discharging characteristics of the battery were evaluated for the first time.

Similarly, each of the other lithium ion batteries of Examples B1a to B3b and Comparative Examples B1a to B7b obtained as described above were left in the atmosphere for 24 hours. Similarly, the battery was connected to a battery charge/discharge evaluation system HJ1001SD8 manufactured by Hokuto Denko Co., Ltd., and charged and discharged under the conditions shown in Tables 4 and 5, to evaluate the charge and discharge characteristics of the battery for the first time.

The evaluation results are summarized in Tables 4 and 5 together with the charging and discharging conditions.

As is clear from Tables 4 and 5, excellent results were obtained in the present invention, whereas satisfactory results were not obtained in the comparative example.

P100...Solid electrolyte, P1...First mixture, P2...Calculated body, P3'...Crystalline solid electrolyte (first electrolyte), P3...First electrolyte portion, P4'...Second electrolyte, P4...Second electrolyte part, P5... active material part, Q1... first molded body, Q3... second molded body, Q6... second mixture, Q7... third molded body, 100... lithium ion battery, 10... composite, 30... negative electrode, 41... Current collector, 42... Current collector, 300... Wearable device, 301... Band, 302... Sensor, 303... Display section, 304... Processing section, WR... Wrist

Claims (16)

A solid electrolyte represented by the following compositional formula (1).
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.) A composite comprising the solid electrolyte and active material according to claim 1,
an electrode provided on one side of the composite;
A current collector provided on the other surface of the composite body. The battery according to claim 2, wherein the active material is a positive electrode active material containing Li and O. The battery according to claim 2 or 3, wherein the electrode is metal Li. An electronic device comprising the battery according to any one of claims 2 to 4. A first mixing step of obtaining a first mixture by mixing multiple types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1);
a first heating step of subjecting the first mixture to a first heat treatment to form a pre-fired body;
A method for producing a solid electrolyte, comprising: a second heating step of subjecting the pre-fired body to a second heat treatment to form a crystalline solid electrolyte represented by the following compositional formula (1).
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.) The method for manufacturing a solid electrolyte according to claim 6, wherein the heating temperature in the first heat treatment is 500°C or more and 650°C or less. The method for manufacturing a solid electrolyte according to claim 6 or 7, wherein the heating temperature in the second heat treatment is 800°C or more and 1000°C or less. A first mixing step of obtaining a first mixture by mixing multiple types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1);
a heating step of subjecting the first mixture to a heat treatment to form a first electrolyte portion;
Forming a second electrolyte part by melting the second electrolyte with a second electrolyte containing Li, B, and O in contact with the first electrolyte part to form a second electrolyte part in contact with the first electrolyte part. A method for producing a solid electrolyte, comprising:
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.) A first mixing step of obtaining a first mixture by dissolving and mixing multiple types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1) in a solvent;
a first molded body forming step of forming a first molded body using an active material;
a composite forming step of heating the first mixture impregnated in the first molded body to form a composite containing a crystalline first electrolyte portion and the active material;
an electrode forming step of forming an electrode on one side of the composite;
A method for manufacturing a battery, comprising a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.) A first mixing step of obtaining a first mixture by dissolving and mixing multiple types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1) in a solvent;
a first molded body forming step of forming a first molded body using an active material;
a second molded body forming step of heating the first mixture impregnated in the first molded body to form a second molded body containing a crystalline first electrolyte portion and the active material; and,
A second electrolyte containing Li, B, and O is brought into contact with the second molded body, the second electrolyte is melted, and the second molded body is filled with the melt of the second electrolyte, and then , a composite forming step of cooling the second molded body filled with the melt of the second electrolyte to form a composite including the first electrolyte part, the second electrolyte part, and the active material;
an electrode forming step of forming an electrode on one side of the composite;
A method for manufacturing a battery, comprising a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.) A claim in which the heat treatment includes a first heat treatment at a heating temperature of 500° C. or more and 650° C. or less, and a second heat treatment performed after the first heat treatment and at a heating temperature of 800° C. or more and 1000° C. or less. Item 12. The method for manufacturing a battery according to item 10 or 11. A first mixing step of obtaining a first mixture by mixing multiple types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1);
a step of forming a pre-fired body by subjecting the first mixture to a first heat treatment to obtain a pre-fired body;
a second mixing step of mixing the pre-fired body and the active material to obtain a second mixture;
a third molded body forming step of molding the second mixture to form a third molded body;
a composite forming step of subjecting the third molded body to a second heat treatment to form a composite containing a crystalline first electrolyte portion and the active material;
an electrode forming step of forming an electrode on one side of the composite;
A method for manufacturing a battery, comprising a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.) A first mixing step of obtaining a first mixture by mixing multiple types of raw materials containing metal elements constituting a lithium composite metal oxide represented by the following compositional formula (1);
a step of forming a pre-fired body by subjecting the first mixture to a first heat treatment to obtain a pre-fired body;
a second mixing step of mixing the pre-fired body and the active material to obtain a second mixture;
a third molded body forming step of molding the second mixture to form a third molded body;
a second molded body forming step of subjecting the third molded body to a second heat treatment to form a second molded body containing a crystalline first electrolyte portion and the active material;
A second electrolyte containing Li, B, and O is brought into contact with the second molded body, the second electrolyte is melted, and the second molded body is filled with the melt of the second electrolyte, and then , a composite forming step of cooling the second molded body filled with the melt of the second electrolyte to form a composite including the first electrolyte part, the second electrolyte part, and the active material;
an electrode forming step of forming an electrode on one side of the composite;
A method for manufacturing a battery, comprising a current collector forming step of forming a current collector on the other side of the composite.
(Li _7-3x Ga _x ) (La _3-ym Nd _y Y _m ) Zr ₂ O ₁₂ ...(1)
(In formula (1), 0.10≦x<1.00, 0.01≦y≦0.20, and 0.00<m≦0.15 are satisfied.) The method for manufacturing a battery according to claim 13 or 14, wherein the heating temperature in the first heat treatment is 500°C or more and 650°C or less. The method for manufacturing a battery according to any one of claims 13 to 15, wherein the heating temperature in the second heat treatment is 800°C or more and 1000°C or less.

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