JP2000331680A - Lithium secondary battery and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [Problem] There is a problem that it is difficult to uniformly disperse constituent elements. A method of manufacturing a lithium secondary battery in which a solid electrolyte (5) is interposed between a positive electrode (3) and a negative electrode (6) and sealed in a positive electrode can (1) and a negative electrode can (8) is provided. And a water-soluble lithium salt and a water-soluble manganese salt having an element ratio of lithium: manganese of 1.02 to 1.34: 1.6.
An aqueous solution of sodium carbonate is added to the mixed aqueous solution of 6 to 1.98, and lithium carbonate and manganese carbonate are coprecipitated and sintered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lithium secondary battery and a method of manufacturing the same, and more particularly, to a lithium secondary battery using a lithium manganese composite oxide as an active material of an electrode and a method of manufacturing the same.

[0002]

2. Description of the Related Art As an active material for a lithium secondary battery having a high voltage and a high energy density, a lithium manganese composite oxide which is inexpensive and excellent in safety is expected. As such a lithium manganese composite oxide, there is a spinel type lithium manganate.
However, spinel-type lithium manganate has a problem of poor cycle characteristics.To solve this problem, in order to solve this problem, the composition of lithium excess or part of manganese is changed with alkaline earth metals such as magnesium or transition metals other than manganese. An active material having a substituted composition has been studied (for example, see JP-A-6-215772).

However, unlike the case of a composition having an element ratio of lithium: manganese of 1: 2, the composition of lithium is excessive, or a part of manganese is replaced by an alkaline earth metal such as magnesium or a transition metal other than manganese. In such a composition, it is difficult to uniformly disperse the elements by the conventional solid phase synthesis, and therefore, there is a problem that the desired characteristics are not easily exhibited due to the formation and the residual of the secondary phase and the like.

[0004] When trying to achieve uniform synthesis by solid-phase synthesis, and when synthesizing a small amount, baking and mixing and pulverization are generally performed a plurality of times. Such a method is less likely to generate a secondary phase than simply raising the firing temperature or increasing the firing time, but it complicates the process, costs and takes time, and impurities are mixed during mixing and grinding. Easy to do and not suitable for mass production.

[0005] As a solid phase synthesis method that may be applicable to mass production, for example, a method of obtaining a spinel compound having a lithium excess by holding a mixture of a lithium compound and a manganese compound at a temperature of 490 to 550 ° C and firing the mixture. (For example, see Japanese Patent Application Laid-Open No. 9-161800).

However, even in this method, 490
It is necessary to lengthen the holding time in the range of ℃ 550 ° C., increase the final firing temperature, or lengthen the firing time, during which lithium evaporation and defect formation in the spinel structure tend to occur. It is. This tendency becomes remarkable as the amount of lithium becomes excessive.
Lithium beyond the range disclosed in Publication No. 800:
With a composition of manganese = 1.34: 1.66, the capacity is significantly reduced.

As described above, since it is difficult to uniformly disperse the constituent elements in the solid phase synthesis method, a liquid phase synthesis method is often studied.
Such liquid phase synthesis methods include, for example, organic salts of manganese such as manganese acetate or acetylacetonatomanganese, lithium salts in solution such as lithium nitrate, sol stabilizers such as gelatin, and ammonia solutions, for example. Sol with an alkaline solution, followed by heat treatment (for example, JP-A-8-13867).
No. 4). The reason for adding the sol stabilizer is that without it, the separation of lithium and manganese will occur and uniform dispersion of the components will not be achieved.

However, in this method, since the organic acid salt is used, the raw material mixture becomes a viscous sol, and the handling is not easy. This method also uses Li as an intermediate product.
Since a complex salt of Mn ₂ (CH ₃ COO) ₃ (OH) is formed, it is suitable for synthesis of a composition having an element ratio of lithium: manganese of 1: 2, but is uniformly dispersed by adding an element such as magnesium or nickel. Not suitable for.

The present invention has been made in view of such a problem of the conventional method, and has solved the problems of the conventional method caused by the difficulty in uniformly dispersing the constituent elements, and a method of manufacturing the same. The purpose is to provide.

[0010]

To achieve the above object, a method for manufacturing a lithium secondary battery according to claim 1 includes:
In a method for manufacturing a lithium secondary battery in which a solid electrolyte is interposed between a positive electrode and a negative electrode and sealed in a positive electrode can and a negative electrode can, the positive electrode and / or the negative electrode may be made of a water-soluble lithium salt and a water-soluble manganese salt. An aqueous solution of sodium carbonate is added to a mixed aqueous solution dissolved so that the element ratio of lithium: manganese is 1.02 to 1.34: 1.66 to 1.98, and lithium carbonate and manganese carbonate are coprecipitated and fired. It is characterized by sintering the fired product.

According to a second aspect of the present invention, in the lithium secondary battery, a solid electrolyte is interposed between the positive electrode and the negative electrode, and the positive electrode and the negative electrode are sealed in the positive electrode can and the negative electrode can. With Li [Li _x Mn _2-x ] O ₄
(0.02 ≦ x ≦ 0.34).

According to a third aspect of the present invention, there is provided a method of manufacturing a lithium secondary battery in which a solid electrolyte is interposed between a positive electrode and a negative electrode and sealed in a positive electrode can and a negative electrode can. The positive electrode and / or the negative electrode were prepared by mixing a water-soluble lithium salt and a water-soluble manganese salt with an element ratio of lithium: manganese of 1.02 to 1.34: 1.66 to 1.98.
A magnesium aqueous solution and / or a nickel aqueous solution and a sodium carbonate aqueous solution are added to a mixed aqueous solution dissolved so that carbonate is coprecipitated and calcined, and then the calcined product is sintered.

Further, in the method of manufacturing a lithium secondary battery according to claim 4, in the lithium secondary battery sealed in a positive electrode can and a negative electrode can with a solid electrolyte interposed between the positive electrode and the negative electrode, And / or Li [Li _x M
_{g y Ni z Mn 2-xyz} ] O 4 (0.00 ≦ x ≦ 0.3
4, 0.00 ≦ y ≦ 0.35, 0.00 ≦ z ≦ 0.5
5) is used.

[0014]

The respective constituent elements are uniformly dispersed in the aqueous solution by adjusting and mixing each constituent element in an aqueous solution having a predetermined molar ratio in the form of a salt readily soluble in water. By adding an aqueous solution obtained by dissolving easily soluble sodium carbonate in water, carbonates of each component element that is hardly soluble in water are rapidly precipitated. According to this method, a raw material powder in which the salts of the constituent elements are uniformly dispersed is obtained, and by firing this, an active material having a high purity can be obtained. By using at least one of the negative electrodes, the cycle characteristics of the lithium secondary battery can be improved.

[0015]

Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view showing a configuration example of a lithium secondary battery according to the present invention, wherein 1 is a positive electrode can, 2 is a positive electrode current collecting layer, 3 is a positive electrode, 4 is an insulating packing, and 5 contains a solid electrolyte or an electrolyte. Separator, 6 is a negative electrode, 7 is a negative electrode current collecting layer, 8
Denotes a negative electrode can.

According to the present invention, the water-soluble lithium salt and manganese salt are prepared by mixing lithium: manganese in an amount of 1.02 to 1.34:
An aqueous solution of sodium carbonate is added to a mixed aqueous solution dissolved to a concentration of 1.66 to 1.98 to coprecipitate lithium carbonate and manganese carbonate, and the coprecipitated mixture is calcined to obtain an electrochemical solution close to the theoretical capacity. [Li
_x Mn _2-x ] O ₄ (0.02 ≦ x ≦ 0.34) is synthesized and sintered to form an electrode or [Li _x
Mn _2-x ] O4 (0.00 ≦ x ≦ 0.34) When replacing part of manganese in a lithium manganese composite oxide having a basic composition with at least one element of magnesium and nickel, An aqueous solution of sodium carbonate is added to a mixed aqueous solution of lithium, manganese, magnesium and / or nickel to obtain a coprecipitated mixture of carbonates, and the coprecipitated mixture is calcined to have an electrochemical capacity close to the theoretical capacity [Li _x Mg _{y Ni z Mn 2-xyz]} O 4 (0.0
0 ≦ x ≦ 0.34, 0.00 ≦ y ≦ 0.35, 0.00
.Ltoreq.z.ltoreq.0.55), which is sintered to form electrodes, and these electrodes are used for at least one of the positive electrode and the negative electrode.

In the active material used in the present invention, nitrates, sulfates, chlorides and the like can be used as salts of the respective constituent elements, and nitrates are most preferable. The reason is that even if a small amount of nitrate ion is taken into the raw material powder, it is decomposed at a relatively low temperature as compared with other ions, so that it does not easily remain in the fired product.

When a part of manganese is replaced by another element, various chelating agents are often used in order to adjust the rate of formation of carbonate of each constituent element. However, since chelating agents are expensive, it is preferable not to use them if possible. There is no particular need to use a chelating agent for the addition of magnesium and nickel in the present invention.

Regarding the ratio of the constituent elements, in the case of a composition having an excessive amount of lithium, [Li _x Mn _2-x ] O ₄ (0.02 ≦ x ≦
0.34) is desirable. x <0.
In the range of 02, the cycle characteristics cannot be improved,
In the range of x> 0.34, the voltage becomes less than 3 V, and the energy density decreases. When replacing manganese with magnesium or nickel, [Li _x Mg _y Ni _z Mn
_2-xyz ] O ₄ (0.00 ≦ x ≦ 0.34, 0.00 ≦
A composition range represented by y ≦ 0.35, 0.00 ≦ z ≦ 0.55) is desirable. When replacing with magnesium,
In the range of y> 0.35, magnesium is not completely dissolved,
A heterogeneous phase of magnesium oxide is formed. In the case of replacing with nickel, the crystallinity is extremely reduced in the range of z> 0.55, and the cycle characteristics are deteriorated.

The firing of the mixed powder comprising the carbonates of the respective constituent elements is carried out in a temperature range of 500 ° C. to 650 ° C. for 10 hours to 50 hours. The reason for this is that the reaction does not proceed sufficiently below 500 ° C., while at higher temperatures above 650 ° C., especially in compositions rich in lithium, the thermal decomposition product Li ₂ MnO
₃ occurs.

The sintered electrode according to the present invention may be, for example, Li _1.3 as an inorganic solid electrolyte in addition to the active material included in the present invention.
Al _0.3 Ti _1.7 (PO ₄ ) ₃ , Li _3.6 Ge _0.6 V
Oxide crystalline solid electrolyte such as _0.4 O ₄ , 40 Li _{2
O-35B 2 O 3 -25LiNbO 3} , 30LiI-4
1Li ₂ O-29P ₂ O ₅ was added a proper amount of an oxide-based amorphous solid electrolytes such as are formed by normal pressure sintering or pressure sintering at a predetermined temperature.

The electrodes used for the positive electrode 3 include the above-mentioned electrodes. For the negative electrode 6, a carbon material, metallic lithium, or a lithium transition metal composite oxide having a lower potential than the positive electrode active material is used. Of course, the above-mentioned electrode may be used for the negative electrode, and the electrode of the present invention may be used for both the positive electrode and the negative electrode. In that case, the one with a more noble potential is used as the positive electrode, and the one with a lower potential is used as the negative electrode.

To produce the positive electrode 3 and the negative electrode 6,
(1) An active material, an oxide-based amorphous solid electrolyte, a conductive material such as gold, and a molding aid are dispersed in water or an organic solvent to prepare a slurry, and this slurry is formed on a film. Alternatively, after coating and drying on a current collector, it is cut and sintered, or (2) an active material, an oxide-based amorphous solid electrolyte, and a conductive material such as gold are directly or A method is used in which a molding aid is added, granulated, put into a mold, pressed by a press, and then sintered.

Examples of the molding aid usable here include polytetrafluoroethylene, polyacrylic acid, carboxymethylcellulose, polyvinylidene fluoride, polyvinyl alcohol, diacetylcellulose, hydroxypropylcellulose, polybutyral, polyvinyl chloride and polyvinylpyrrolidone. One or two such as
Mixtures of more than one species.

The shape of the battery may be any of a coin type, a square type, a button type and a flat type.

The electrolyte 5 may be an organic electrolyte in which a required electrolyte salt is dissolved in an organic solvent, a solid polymer electrolyte in which an electrolyte salt is dissolved in an ion-conductive polymer material, a gel electrolyte in which these are combined, or An inorganic solid electrolyte made of an inorganic material can be used. When an organic electrolyte is used for the electrolyte 5, a separator for separating the positive electrode 3 and the negative electrode 6 is required.

The organic solvent used for the organic electrolyte includes, for example, ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyrolactone, sulfolane,
There is one or a mixture of two or more solvents selected from 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and methylethyl carbonate.

Examples of the electrolyte salt include LiClO ₄ ,
LiBF ₄ , LiPF ₆ , LiCF ₃ SO ₃ , LiN
Lithium salts such as (CF ₃ SO ₂ ) ₂ can be mentioned.

As the separator, for example, a nonwoven fabric made of polyolefin fiber or a microporous film made of polyolefin can be used. Here, examples of the polyolefin include polyethylene and polypropylene.

As the ion conductive polymer material, for example, a polymer having an ethylene oxide skeleton represented by polyethylene oxide, a polymer having an acrylonitrile skeleton represented by polyacrylonitrile, or a mixture or copolymer thereof is used. is there.

As the inorganic solid electrolyte, for example, Li _1.3
Al _0.3 Ti _1.7 (PO ₄ ) ₃ , Li _3.6 Ge _0.6 V
Oxide crystalline solid electrolyte such as _0.4 O ₄ , 40 Li _{2
O-35B 2 O 3 -25LiNbO 3} , 30LiI-4
An oxide-based amorphous solid electrolyte such as 1Li ₂ O-29P ₂ O ₅ or 1Li ₃ PO ₄ -63Li ₂ S-36S
A sulfide-based amorphous solid electrolyte such as iS ₂ can be given.

The positive electrode current collecting layer 2 and the negative electrode current collecting layer 7 are disposed for adhesion and current collection or contact and current collection between the positive electrode can 1 or the negative electrode can 8 and the positive electrode 3 or the negative electrode 6. In the case of collecting current from an electrode, a polymer adhesive material in which conductive particles are dispersed may be mentioned, and in the case of collecting current from an electrode not included in the present invention, an aluminum foil or a copper foil may be used.

[0033]

EXAMPLES (Example 1) First, solutions obtained by dissolving 0.2 mol of lithium nitrate and 0.25 mol of manganese nitrate in pure water were mixed, and the mixture was stirred for 0.1 mol.
3 mol of a saturated aqueous solution of sodium carbonate was added to co-precipitate lithium carbonate and manganese carbonate. 1 coprecipitation mixture
After aging for 3 days, the mixture was filtered, washed with water and dried to prepare a raw material powder.

The obtained raw material powder is treated at 630 ° C. in the atmosphere for 24 hours.
After firing for an hour, an active material was synthesized.

As the inorganic solid electrolyte, 40%
_{Li 2 O-35B 2 O 3} -25LiNbO 3, 30Li
_{I-41Li 2 O-29P 2} O 5, and Au as a conductive agent were mixed predetermined amounts, after tape-casting, to form an electrode by sintering at a given temperature.

(Example 2) First, 0.1 mol of lithium nitrate, 0.165 mol of manganese nitrate, 0.0 mol
A solution prepared by dissolving 35 mol of magnesium nitrate in pure water was mixed, and the mixed solution was stirred for 0.3 mol.
One liter of a saturated aqueous solution of sodium carbonate was added to co-precipitate lithium carbonate, manganese carbonate and magnesium carbonate. After aging the coprecipitated mixture for 1 to 5 days, the mixture was filtered, washed with water and dried to prepare a raw material powder.

The obtained raw material powder is heated at 550 ° C. in the atmosphere for 24 hours.
After firing for an hour, an active material was synthesized.

The active material may be used as an inorganic solid electrolyte,
_{Li 2 O-35B 2 O 3} -25LiNbO 3, 30Li
_{I-41Li 2 O-29P 2} O 5, and Au as a conductive agent were mixed predetermined amounts, after tape-casting, to form an electrode by sintering at a given temperature.

Example 3 First, 0.1 mol of lithium nitrate, 0.145 mol of manganese nitrate,
A solution in which 55 mol of nickel nitrate was dissolved in pure water was mixed, and 0.3 mol of a saturated aqueous solution of sodium carbonate was added to the mixed solution while stirring to co-precipitate lithium carbonate, manganese carbonate and nickel carbonate. After aging the coprecipitated mixture for 1 to 5 days, the mixture was filtered, washed with water and dried to prepare a raw material powder.

The obtained raw material powder is heated at 550 ° C. in the atmosphere for 24 hours.
After firing for an hour, an active material was synthesized.

As an inorganic solid electrolyte, 40%
_{Li 2 O-35B 2 O 3} -25LiNbO 3, 30Li
_{I-41Li 2 O-29P 2} O 5, and Au as a conductive agent were mixed predetermined amounts, after tape-casting, to form an electrode by sintering at a given temperature.

Comparative Example 1 Hereinafter, a comparative example of a method for producing Li [Li _1/3 Mn _5/3 ] O ₄ in the solid phase synthesis method will be described.

First, 0.2 mol of lithium hydroxide monohydrate and 0.25 mol of manganite were mixed.
No. 0 alumina ball and pure water were added and mixed and pulverized by a pot mill for 24 hours. The mixed and pulverized slurry was vacuum dried to prepare a raw material powder.

The obtained raw material powder is treated at 630 ° C. in the atmosphere for 24 hours.
After firing for an hour, an active material was synthesized.

The active material may be used as an inorganic solid electrolyte.
_{Li 2 O-35B 2 O 3} -25LiNbO 3, 30Li
_{I-41Li 2 O-29P 2} O 5, and Au as a conductive agent were mixed predetermined amounts, after tape-casting, to form an electrode by sintering at a given temperature.

Comparative Example 2 Hereinafter, a comparative example of a method for producing Li [Mg _0.35 Mn _1.65 ] O ₄ in a solid phase synthesis method will be described.

First, 0.1 mol lithium hydroxide monohydrate, 0.165 mol manganese dioxide and 0.035 mol
mol of magnesium nitrate, and a φ10 alumina ball and pure water were added and mixed and pulverized by a pot mill for 24 hours. The mixed and pulverized slurry was vacuum dried to prepare a raw material powder.

The obtained raw material powder is heated at 550 ° C. in the atmosphere for 24 hours.
After firing for an hour, an active material was synthesized.

As an inorganic solid electrolyte, 40%
_{Li 2 O-35B 2 O 3} -25LiNbO 3, 30Li
_{I-41Li 2 O-29P 2} O 5, and Au as a conductive agent were mixed predetermined amounts, after tape-casting, to form an electrode by sintering at a given temperature.

Comparative Example 3 A comparative example of a method for producing Li [Ni _0.55 Mn _1.45 ] O ₄ in the solid phase synthesis method is described below.

First, 0.1 mol of lithium hydroxide monohydrate, 0.145 mol of manganese dioxide,
55 mol of nickel nitrate was mixed, alumina balls of φ10 and pure water were added, and the mixture was pulverized by a pot mill for 24 hours. The mixed and pulverized slurry was vacuum dried to prepare a raw material powder.

The raw material powder thus obtained was heated at 550 ° C. in the atmosphere for 24 hours.
After firing for an hour, an active material was synthesized.

The active material may be used as an inorganic solid electrolyte,
_{Li 2 O-35B 2 O 3} -25LiNbO 3, 30Li
_{I-41Li 2 O-29P 2} O 5, and Au as a conductive agent were mixed predetermined amounts, after tape-casting, to form an electrode by sintering at a given temperature.

[Evaluation of Electrochemical Capacity and Cycle Characteristics] Table 1 shows the results of charge / discharge tests using prototype batteries using electrodes synthesized by the methods shown in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3. Is shown. The prototype battery was manufactured as follows. A positive electrode formed by the method shown in Examples 1 and 2 and Comparative Examples 1 and 2, and a negative electrode active material 97 made of graphite
A negative electrode prepared by applying a paste obtained by adding N-methylpyrrolidinone with 3 wt% of PVDF as a binder and adding N-methylpyrrolidinone on a copper foil of a current collector and vacuum-drying at 120 ° C. It was adjusted to a size of φ16, layered with a polypropylene microporous membrane interposed therebetween, and impregnated with a 1: 1 vol% solution of propylene carbonate: dimethyl carbonate = 1M LiClO ₄ to form a coin cell.

The charge / discharge test conditions were such that the current density was 0.03 mA
/ Cm ² , 3.5 to 2.5 V (Example 1, Comparative Example 1),
4.5 V to 3.0 V (Example 2, Comparative Example 2). Further, a positive electrode formed by the method shown in Example 3 and Comparative Example 3, a negative electrode using the electrode formed by the method shown in Example 1, and Li _1.3 Al _0.3 Ti as a solid electrolyte
_{1.7 (PO 4) 3, 40Li} 2 O-35B 2 O 3 -25
_{LiNbO 3, 30LiI-41Li 2 O} -29P 2 O
₅ is mixed in a predetermined amount and sintered.
The size was adjusted to 5 and a coin cell was assembled. The charge / discharge test conditions were as follows: current density: 0.03 mA / cm < ² >;
0 V was applied.

[0056]

[Table 1]

Example 1 is superior to Comparative Example 1 in both the initial discharge capacity and the capacity retention after 100 cycles. Further, Example 2 has an initial discharge capacity of 10% compared to Comparative Example 2.
Both capacity retention after 0 cycles are excellent. Furthermore, Example 3 is superior to Comparative Example 3 in both the initial discharge capacity and the capacity retention after 100 cycles.

Thus, Examples 1 to 3 using the electrode made of the active material produced by the liquid phase synthesis method of the present invention are comparative examples using the electrode made of the active material produced by the conventional solid phase synthesis method. From 1 to 3, it is presumed that both the initial discharge capacity and the cycle characteristics are excellent because the former synthesis method synthesized an active material in which constituent elements were uniformly dispersed.

[0059]

As described above, in the method for manufacturing a lithium secondary battery according to claim 1, the positive electrode and / or the negative electrode
The water-soluble lithium salt and the water-soluble manganese salt have a lithium: manganese element ratio of 1.02 to 1.34: 1.66 to 1.
Since the sodium carbonate aqueous solution is added to the mixed aqueous solution of No. 98 and lithium carbonate and manganese carbonate are coprecipitated and sintered, the raw material powder in which the salts of the respective constituent elements are uniformly dispersed can be fired, and the purity can be improved. By using an active material having a high value for at least one of the positive electrode and the negative electrode, a lithium secondary battery having excellent cycle characteristics can be obtained.

Further, in the lithium battery according to the second aspect,
Li [Li _x Mn _2-x ] O _{4 for the} positive electrode and / or the negative electrode
Since (0.02 ≦ x ≦ 0.34) is desired, a lithium secondary battery having excellent cycle characteristics can be obtained.

In the method for manufacturing a lithium secondary battery according to the third aspect, the positive electrode and / or the negative electrode may be formed by mixing a water-soluble lithium salt and a water-soluble manganese salt with an element ratio of lithium: manganese of 1.02 to 1.0. 34: A magnesium aqueous solution and / or a nickel aqueous solution and a sodium carbonate aqueous solution are added to a mixed aqueous solution of 1.66 to 1.98 to cause coprecipitation of carbonate and sintering, so that salts of the respective constituent elements are uniformly dispersed. By using an electrode obtained by sintering a high purity active material for at least one of the positive electrode and the negative electrode, a lithium secondary battery having excellent cycle characteristics can be obtained.

Further, in the lithium secondary battery according to the fourth aspect, Li [Li _x Mg _y N
_{i z Mn 2-xyz] O} 4 (0.00 ≦ x ≦ 0.34,
0.00 ≦ y ≦ 0.35, 0.00 ≦ z ≦ 0.55), it is possible to obtain a lithium secondary battery having excellent cycle characteristics.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration example of a lithium secondary battery according to the present invention.

[Explanation of symbols]

1 ... Positive electrode can, 2 ... Positive electrode current collecting layer, 3 ... Positive electrode, 4 ...
Insulating packing, 5: Separator containing solid electrolyte or electrolytic solution, 6: Negative electrode, 7: Negative current collecting layer, 8:
… Negative electrode can

Continuing from the front page (72) Inventor Yoko Mishima 3-5 Koikodai, Seika-cho, Soraku-gun, Kyoto Prefecture Inside the Central Research Laboratory, Sera Corporation (72) Inventor Shinji Magome 3-5 Koikodai, Seika-cho, Soraku-gun, Kyoto Kyoto Inside the Central Research Laboratory of Sera Corporation (72) Inventor Makoto Osaki 3-5 Koukodai, Seika-cho, Soraku-gun, Kyoto Prefecture Inside of Central Research Laboratory Kyoto Sera Corporation (72) Inventor Ei Higuchi 3-5-2 Kodaidai, Seika-cho, Kyoto Prefecture Address Kyocera Corporation Central Research Laboratory F-term (reference) 5H003 AA04 BA01 BA03 BB05 BC01 BD00 BD03

Claims (4)

[Claims] 1. A method for manufacturing a lithium secondary battery in which a solid electrolyte is interposed between a positive electrode and a negative electrode, and the positive electrode can and the negative electrode are sealed in a positive electrode can and a negative electrode can. Elemental manganese salt with an element ratio of lithium: manganese of 1.02 to 1.34: 1.66 to 1.98
A method for producing a lithium secondary battery, comprising: adding an aqueous solution of sodium carbonate to a mixed aqueous solution of the above, coprecipitating lithium carbonate and manganese carbonate, firing the resultant, and sintering the fired product. 2. A lithium secondary battery sealed in a positive electrode can and a negative electrode can with a solid electrolyte interposed between the positive electrode and the negative electrode, wherein the positive electrode and / or the negative electrode include Li [Li _x Mn
_2-x ] O ₄ (0.02 ≦ x ≦ 0.34). 3. A method of manufacturing a lithium secondary battery in which a solid electrolyte is interposed between a positive electrode and a negative electrode and sealed in a positive electrode can and a negative electrode can. Elemental manganese salt with an element ratio of lithium: manganese of 1.02 to 1.34: 1.66 to 1.98
A magnesium aqueous solution and / or a nickel aqueous solution and a sodium carbonate aqueous solution are added to a mixed aqueous solution of the above, and the carbonate is coprecipitated and fired, and then the fired product is sintered. 4. A lithium secondary battery sealed in a positive electrode can and a negative electrode can with a solid electrolyte interposed between a positive electrode and a negative electrode, wherein Li [Li _x Mg
_y Ni _z Mn _2-xyz ] O ₄ (0.00 ≦ x ≦ 0.3
4, 0.00 ≦ y ≦ 0.35, 0.00 ≦ z ≦ 0.5
5) A lithium secondary battery using the above item.