JP2002226213A - Lithium manganese complex oxide powder, its production method, cathode active material for lithium secondary cell, and lithium secondary cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a lithium manganese complex oxide powder useful as a cathode active material for a lithium secondary cell having a high battery performance, especially high in capacity maintenance ratio and retention property, and low in the amount of elution of Mn ions even if contacting an electrolyte of the lithium secondary cell when using the above powder as the cathode active material for the lithium secondary cell. SOLUTION: The lithium manganese complex oxide powder concerning this invention is the one denoted by the formula (1); LixMn2-yMeyO4-z (Me denotes Al, Zr or Zn, x takes the value of 0<x<2, y takes the value of 0<=y<0.6 and z takes the value of 0<=z<=2.0) and it is obtained by heat-treating the pulverized powder of the lithium manganese complex oxide denoted by the formula (1) at 300-800 deg.C to make its average particle size 0.1-50 μm and its BET specific surface area 0.1-2.0 m2/g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a lithium manganese composite oxide powder which has a small manganese ion elution amount even when contacted with a non-aqueous electrolyte of a lithium secondary battery and is useful as a positive electrode active material of a lithium secondary battery. The present invention relates to a method for producing the same, a positive electrode active material for a lithium secondary battery containing the same, and a lithium secondary battery.

[0002]

2. Description of the Related Art In recent years, portable electronic devices have become more portable.
As cordless technology has rapidly progressed, lithium secondary batteries have begun to be used as power sources for small electronic devices. Regarding this lithium secondary battery, in 1980 Mizushima et al. Reported that lithium cobaltate was useful as a positive electrode active material of a lithium secondary battery (“Material Research Bulletin” vol. 115, 783-789 (19)
Since 1980)), research and development on lithium-based composite oxides have been actively promoted, and lithium cobaltate, lithium nickelate, lithium manganate and the like have been known as positive electrode active materials. Among them, lithium manganate (LiMn ₂ O ₄ ) has been variously proposed since the raw material is cheaper and the production cost is lower than lithium cobaltate or lithium nickelate.

However, since LiMn ₂ O ₄ is incorporated into the crystal structure in a stable form when the crystal structure is distorted by charge / discharge, it is difficult for LiMn to be released during repeated charge / discharge. The cycle characteristics of the secondary battery deteriorate. LiMn ₂ O ₄ is repeatedly charged and discharged, so that Mn ions are eluted into the electrolyte layer.
This also deteriorates the cycle characteristics of the lithium secondary battery.

On the other hand, for example, a part of the Mn atom is replaced with C
Methods for stabilizing the crystal structure of lithium manganese composite oxide by substituting elements such as o, Ni, Cr, Fe (Japanese Patent Application Laid-Open Nos. 2-278661, 3-219571, 4-160767) Gazette) has been proposed. In these methods, a part of Mn is changed to Co, Ni, C
By reducing the lattice constant of LiMn ₂ O ₄ by substituting it with r, Fe, or the like, the crystal structure of LiMn ₂ O ₄ is strengthened to prevent a decrease in discharge capacity due to the destruction of the crystal structure.

[0005]

However, the lithium manganese composite oxide obtained by the above method has a problem in that when the number of charge / discharge cycles is increased or the standing period is lengthened,
Although the release of i-ions is sufficiently suppressed, there is a problem that the elution of Mn ions cannot be sufficiently suppressed.

Regarding the suppression of the elution of Mn ions, other than the method of substituting a part of Mn atoms with Co or the like as described above, a method of adding a certain additive to a lithium manganese composite oxide, Various methods for coating the surface of the lithium manganese composite oxide and the like have been proposed. For example, as a method of adding a certain additive to the lithium manganese composite oxide, as a trapping agent for trapping a manganese component in the positive electrode, lithium phosphate, lithium tungstate, lithium silicate, aluminum nitride, lithium borate, molybdenum A method of containing at least one selected from the group consisting of lithium oxide and a cation exchange resin (JP-A-20
And a method for coating the surface of a lithium manganese composite oxide with Li
_{(1 + x)} Mn _(2-x) O _(4-y) (where 0 ≦ x ≦ 0.333
3, a method of forming a LiV ₂ O ₄ layer on the surface of an oxide powder having a spinel structure represented by -0.1 ≦ y ≦ 0.2 (JP-A-2000-3709). However, none of these methods is sufficient to suppress the release of Li ions and the elution of Mn ions.

Therefore, an object of the present invention is to provide a lithium secondary battery which, when used as a positive electrode active material, has a small amount of Mn ions eluted even when it comes into contact with a non-aqueous electrolyte of a lithium secondary battery. Provided is a lithium manganese composite oxide powder useful as a positive electrode active material of a lithium secondary battery having high capacity retention and storage characteristics, a method for producing the same, a positive electrode active material containing the same, and a lithium secondary battery using the positive electrode active material. Is to do.

[0008]

Under such circumstances, the present inventors have conducted intensive studies and as a result, furthermore, heat-treated a pulverized lithium manganese composite oxide represented by a specific structural formula in a specific temperature range. Lithium manganese oxide powder having an average particle diameter and a BET specific surface area within a specific range, a small amount of Mn ions eluted even when contacted with a non-aqueous electrolyte of a lithium secondary battery. It has been found that the use of as a lithium secondary battery positive electrode active material results in a lithium secondary battery having excellent battery performance, particularly capacity retention and storage characteristics, and completed the present invention.

That is, the present invention provides the following general formula (1): Li _x Mn _2-y Me _y O _4-z (1) (where Me is Al, Zr or Zn, and x is 0 <x
<2.0, y takes a value of 0 ≦ y <0.6, and z takes a value of 0 ≦ z ≦ 2.0. ), Wherein the lithium manganese composite oxide powder is obtained by heat-treating a pulverized lithium manganese composite oxide represented by the general formula (1) at 300 to 800 ° C. Having an average particle diameter of 0.1 to 50 μm and a BE
It is intended to provide a lithium manganese composite oxide powder having a T specific surface area of 0.1 to 2.0 m ² / g.

Further, the present invention relates to the following general formula (1): Li _x Mn _2-y Me _y O _4-z (1) (where Me is Al, Zr or Zn, and x is 0 <x
<2.0, y takes a value of 0 ≦ y <0.6, and z takes a value of 0 ≦ z ≦ 2.0. The present invention provides a method for producing a lithium manganese composite oxide powder, which comprises subjecting a pulverized lithium manganese composite oxide represented by the formula) to a heat treatment at 300 to 800 ° C.

Further, the present invention provides a positive electrode active material for a lithium secondary battery, comprising the above-mentioned lithium manganese composite oxide.

Further, the present invention provides a lithium secondary battery using the above-mentioned positive electrode active material for a lithium secondary battery.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
Lithium manganese composite oxide powder according to the present invention is represented by the following general formula _{(1); Li x Mn 2} -y Me y O 4-z (1) ( wherein, Me is Al, Zr or Zn, x is 0 <x
<2.0, y takes a value of 0 ≦ y <0.6, and z takes a value of 0 ≦ z ≦ 2.0. ). The lithium manganese composite oxide has a spinel structure.

In the lithium manganese composite oxide powder according to the present invention, Me is an optional component that substitutes for the site occupied by Mn in the lithium manganese composite oxide represented by the general formula (1). Me is Al, Zr or Zn;
Specifically, any one selected from Al, Zr or Zn, two arbitrarily selected from these, or A
It contains three kinds of l, Zr and Zn. In this specification, the term "or" is used to mean either one of the two types of words connected by "or" and both of them, that is, the meaning including three types. That is, the lithium-manganese composite oxide powder according to the present invention is, for example, an Al-substituted product when Me is only Al, a Zr-substituted product when Me is only Zr, and a Zn-substituted product when Me is only Zn. , When Me is Al and Zr, AlZr
Substitution, AlZn substitution when Me is Al and Zn, AlZrZ when Me is Al, Zn and Zr
It becomes an n-substituted product. Among the lithium-manganese composite oxide powders according to the present invention, Al-substituted, Zr-substituted, Zn-substituted, AlZr-substituted and AlZn-substituted products are particularly suitable for lithium ion intercalation / deintercalation in lithium secondary batteries. This is preferable because the reaction can be performed more smoothly and at a higher potential.

The lithium-manganese composite oxide powder according to the present invention is obtained by subjecting a pulverized lithium-manganese composite oxide represented by the above general formula (1) to a heat treatment at a specific temperature. Lithium manganese composite oxide powder according to the present invention, pulverized lithium manganese composite oxide as a raw material of the powder (hereinafter, also referred to as “intermediate lithium manganese composite oxide”), and further, the intermediate lithium manganese The composition of the lithium manganese composite oxide (hereinafter, also referred to as “raw lithium manganese composite oxide”) as a raw material of the composite oxide is substantially the same as that represented by the general formula (1). . In addition, the lithium manganese composite oxide powder according to the present invention and the intermediate lithium manganese composite oxide have substantially the same particle properties such as an average particle diameter and a BET specific surface area. That is, even if the raw material lithium manganese composite oxide is crushed or the intermediate lithium manganese composite oxide is heat-treated at a specific temperature to obtain the lithium manganese composite oxide powder according to the present invention, the above-mentioned general formula The composition represented by (1) does not substantially change. Further, the intermediate lithium manganese composite oxide and the lithium manganese composite oxide powder according to the present invention have substantially the same particle properties such as an average particle diameter and a BET specific surface area. However, the lithium manganese composite oxide powder according to the present invention has a smoother particle surface than the intermediate lithium manganese composite oxide due to heat treatment at a specific temperature. The amount of Mn ions eluted is small even when contacted with a lithium secondary battery. When this is used as a positive electrode active material for a lithium secondary battery, a lithium secondary battery having excellent battery performance, particularly excellent capacity retention and storage characteristics, can be obtained.

The intermediate lithium manganese composite oxide used in the present invention is obtained by pulverizing the raw material lithium manganese composite oxide. The intermediate lithium manganese composite oxide usually has an average particle diameter of 0.1 to 50 μm, and a BET specific surface area of 0.1 to 2.0 m ² / g, and preferably has an average particle diameter of 3 to 20 μm. And the BET specific surface area is 0.3 to 1.0 m ² / g. When the particle properties of the intermediate lithium manganese composite oxide are within the above range, the average particle diameter and the BET specific surface area of the lithium manganese composite oxide powder according to the present invention are within a specific range described below by the smoothing heat treatment described below. Is desirable. Further, the intermediate lithium manganese composite oxide was obtained by Rosin-Rammler using n
When the value is usually 3 or more, and preferably 3.5 or more, the rosin / lithium manganese composite oxide powder according to the present invention has
This is desirable because the n value by Ramler falls within a specific range described below. The intermediate lithium manganese composite oxide can be obtained by pulverizing the raw material lithium manganese composite oxide or the like, but the shape of the raw material lithium manganese composite oxide and the pulverization method are not particularly limited.

[0017] The lithium manganese composite oxide powder according to the present invention comprises an intermediate lithium manganese composite oxide of 300 to
It is obtained by heat treatment at 800 ° C., preferably 500 to 700 ° C. (hereinafter also referred to as “smoothing heat treatment”). The intermediate lithium manganese composite oxide is produced by grinding the raw material lithium manganese composite oxide, etc.
At this time, defects in the crystal structure and surface portions having high surface energy are formed on the particle surface. The lithium manganese composite oxide powder according to the present invention is subjected to a smoothing heat treatment, whereby the surface of the particles of the intermediate lithium manganese composite oxide is annealed, and the surface energy of the particles is reduced and the surface is smooth. Become. Since the lithium-manganese composite oxide powder according to the present invention has been subjected to the smoothing heat treatment, the amount of Mn in the crystal eluted as manganese ions even when the lithium-manganese composite oxide powder comes into contact with the non-aqueous electrolyte of the lithium secondary battery is reduced.

If the smoothing heat treatment is performed at a temperature lower than 300 ° C., it is not possible to sufficiently anneal a defect structure or a surface having a high surface energy caused by pulverization. Is unfavorably affected because of the change in battery performance. The processing time of the smoothing heat treatment is usually 1 to 10 hours, preferably 4 to 6 hours.

The lithium manganese composite oxide powder according to the present invention has an average particle size of 0.1 to 50 μm, preferably 1 to 20 μm, determined by a laser particle size distribution measuring method.
m, more preferably 4 to 20 μm, particularly preferably 4 to 20 μm.
８8 μm. Further, the BET specific surface area is 0.1 to 2.
0 m ² / g, preferably from 0.1~1.8m ² / g, more preferably 0.8~1.8m ² / g. Further, in the lithium manganese composite oxide powder according to the present invention, if the particle size distribution is sharp, the load applied during charging / discharging becomes uniform and the life of the lithium secondary battery can be prolonged. It is 3.0 or more, preferably 3.5 or more, and more preferably 4.0 to 6.0. Where rosin
The n-value according to Ramler is defined as a rosin-Rammler distribution formula R = a · exp using a laser particle size distribution analyzer.
It is a value calculated by analyzing (−bx ⁿ ), and indicates that the higher the n value, the sharper the particle size distribution.

Since the lithium-manganese composite oxide powder according to the present invention has been subjected to the above-mentioned smoothing heat treatment, the amount of Mn eluted is small even when it comes into contact with the non-aqueous electrolyte of the lithium secondary battery. As the non-aqueous electrolyte of the lithium secondary battery,
Examples thereof include those used as a nonaqueous electrolyte of a lithium secondary battery described below.

Next, a method for producing the lithium manganese composite oxide powder according to the present invention will be described. In the method for producing a lithium manganese composite oxide powder according to the present invention, a pulverized lithium manganese composite oxide represented by the above general formula (1) (intermediate lithium manganese composite oxide) is mixed with 300 parts.
To 800 ° C., preferably 500 to 700 ° C. (hereinafter also referred to as “smoothing heat treatment”).

As described above, the intermediate lithium manganese composite oxide used in the present invention is obtained by pulverizing the raw material lithium manganese composite oxide, and usually has an average particle diameter of 0.1 to 50 μm, In addition, the BET specific surface area is 0.1 to 2.0 m ² / g, preferably, the average particle diameter is 3 to 20 μm, and the BET specific surface area is 0.3 to 1.0.
m ² / g. When the particle properties of the intermediate lithium manganese composite oxide are within the above ranges, the average particle diameter and BET specific surface area of the obtained lithium manganese composite oxide powder are desirably within specific ranges by the smoothing heat treatment. Further, when the intermediate lithium manganese composite oxide has an rosin-Rammler n value of usually 3 or more, preferably 3.5 or more, the rosin-Rammler n value of the obtained lithium manganese composite oxide powder is specified. It is desirable to be within the range.

In the present invention, the smoothing heat treatment is to reduce the surface energy of the particles of the intermediate lithium manganese composite oxide and to smooth the surface by annealing the surfaces of the particles of the intermediate lithium manganese composite oxide as described above. is there. In the production method according to the present invention, by performing the smoothing heat treatment, a lithium manganese composite oxide powder in which Mn in the crystal is hardly eluted as manganese ions even when the nonaqueous electrolyte of the lithium secondary battery is contacted is obtained. be able to.

If the smoothing heat treatment is performed at a temperature lower than 300 ° C., it is not possible to sufficiently anneal a defect structure or a surface having a high surface energy, which appears due to pulverization. Is not preferable since the composition changes due to the above-mentioned effects and adversely affects battery performance.
The processing time of the smoothing heat treatment is usually 1 to 10 hours, preferably 4 to 6 hours. Further, the smoothing heat treatment may be performed in any of an atmosphere, an inert atmosphere such as Ar and N ₂ , or an oxygen atmosphere, and is not particularly limited.

After the smoothing heat treatment, the obtained lithium manganese composite oxide powder is appropriately cooled and pulverized, if necessary, to obtain a lithium manganese composite oxide powder. This pulverization treatment is appropriately performed, for example, when the lithium manganese composite oxide powder obtained by firing is in the form of a brittlely bonded block, but the lithium manganese composite oxide powder itself has the above-mentioned specific average particle size. It has a diameter and a BET specific surface area. The obtained lithium manganese composite oxide powder has an average particle diameter of 0.1 to 50 μm, preferably 1 to 50 μm.
-20 μm, more preferably 4-20 μm, particularly preferably 4-8 μm, and a BET specific surface area of 0.1-0.1 μm.
2.0 m ² / g, preferably from 0.1~1.8m ² / g, more preferably 0.8~1.8m ² / g. The n value determined by Rosin-Rammler is 3.0 or more, preferably 3.5 or more, and more preferably 4.0 to 6.0.

In the above-mentioned production method, the intermediate lithium manganese composite oxide is obtained, for example, by calcining a mixture of a manganese compound and a lithium compound or, if necessary, further adding an aluminum compound, a zirconium compound or a zinc compound. It can be produced by mixing and baking this as a mixture of a manganese compound, a lithium compound, an aluminum compound, a zirconium compound or a zinc compound. Hereinafter, a method for producing the intermediate lithium manganese composite oxide will be described.

<Manufacturing Method of Intermediate Lithium Manganese Composite Oxide> The manganese compound, lithium compound, or aluminum compound, zirconium compound or zinc compound to be used in the manufacturing method of the intermediate lithium manganese compound oxide may be any of the following. There is no particular limitation as long as it is industrially available, and examples thereof include oxides, hydroxides, carbonates, nitrates and organic acid salts of the respective metals. Specifically, as the manganese compound, electrolytic manganese dioxide and chemically synthesized manganese dioxide are preferable because they are industrially easily available and inexpensive. As a lithium compound, lithium carbonate is easily available industrially,
It is preferable because it is inexpensive. As the aluminum compound, aluminum hydroxide is preferable because it is industrially easily available and inexpensive. Examples of the zirconium compound include zirconium oxide, zirconium hydroxide, and zirconium acetylacetonate. Of these, zirconium oxide and zirconium hydroxide are preferred because they are easily available industrially and are inexpensive. As the zinc compound, zinc oxide is preferable because it is industrially easily available and inexpensive. Any of these raw materials may have any production history, but is preferably as low as possible in content of impurities in order to produce a high-purity lithium-manganese composite oxide. The manganese compound, lithium compound, aluminum compound,
The zirconium compound and the zinc compound can be used alone or in combination of two or more.

The intermediate lithium manganese composite oxide is obtained by mixing the above manganese compound with a lithium compound, or an aluminum compound, a zirconium compound or a zinc compound, if necessary.
Also referred to as a "mixture for firing." ) Is obtained by firing. As a mixing method, either a dry method or a wet method may be used, but a dry method is preferable because of easy production. In the case of dry mixing, it is preferable to use a blender in which the raw materials are uniformly mixed. In the case of wet mixing, for example,
Add and mix a manganese salt to a lithium salt aqueous solution and stir, or add and mix a manganese salt and at least one transition metal compound selected from aluminum compounds, zirconium compounds and zinc compounds to a lithium salt aqueous solution and stir. Is preferred. In the case of wet mixing, it is preferable to remove the water after mixing to obtain a dried mixture.

The firing of the mixture may be performed at a temperature at which a lithium manganese composite oxide can be produced.
To 1100 ° C, preferably 600 to 1000 ° C, more preferably 700 to 900 ° C. When the firing temperature is 900 ° C. or higher, the particle growth heat treatment described later is substantially performed also in the firing step, and thus the particle growth heat treatment is not separately performed before the firing step. This is also preferable because the particle size of the manganese compound can be increased, and the particle size distribution of the obtained intermediate lithium manganese composite oxide becomes sharp. The firing time is 1 to 24 hours, preferably 10 to 20 hours.
Firing may be performed in the air or in an oxygen atmosphere, and is not particularly limited.

Prior to the firing step, a preliminary mixture containing at least a manganese compound and not containing a lithium compound among the materials constituting the firing mixture (hereinafter, referred to as a premix).
Also referred to as "first premix." ) Is prepared, and the first premix is usually 900 ° C. or higher, preferably 940 ° C. or higher, more preferably 1000 to 1200 ° C.
When a heat treatment (hereinafter, also referred to as “particle growth heat treatment”) is performed for a predetermined time, the manganese compound in the first preliminary mixture is oxidized into manganese oxide, and particles of the oxide are grown. It is preferable because it is possible. Here, the first
Specific examples of the preliminary mixture include a manganese compound alone or a mixture of a manganese compound and an aluminum compound, a zirconium compound, or a zinc compound. Note that if the mixture containing the lithium compound is subjected to the particle growth heat treatment, a lithium manganese composite oxide may be generated. Therefore, the lithium compound is not included in the first preliminary mixture. When the first preliminary mixture is mixed with at least a lithium compound and, if necessary, an aluminum compound, a zirconium compound, or a zinc compound after the particle growth heat treatment, the firing mixture can be obtained. The particle growth heat treatment may be performed at least once during or before firing, and may be repeated twice or more as needed during or before firing. By repeatedly performing the particle growth heat treatment, the particle diameter of the manganese oxide can be further increased.

The manganese compound has a particle diameter of 0.1 to 20 μm in a normal state where the particle growth heat treatment is not performed.
It has a broad peak having a plurality of peaks of fine particles having a particle size distribution of less than 1 μm and particles having a particle size distribution of 1 μm or more. However, by the above-described particle growth heat treatment, the manganese oxide is oxidized to generate manganese oxide, and the manganese oxide microparticles grow to substantially eliminate the presence of microparticles smaller than 1 μm and increase the particle diameter. The particle having a particle size of about 2 to 100 μm and a particle size distribution of 2 μm or more becomes extremely sharp with only one peak. If the treatment temperature of the particle growth heat treatment is lower than 900 ° C., the particles hardly grow, which is not preferable. Further, when the temperature is 12
If the temperature exceeds 00 ° C., the manganese compound is sintered, and it becomes difficult to control the particle size. The processing time of the particle growth heat treatment is 0.5 to 48 hours, preferably 1 to 2 hours.
0 hour, more preferably 5 to 12 hours. In addition,
When the treatment time of the particle growth heat treatment is 1 hour or more, the growth of the manganese oxide particles is substantially saturated, but it is preferable to keep the temperature within the above-mentioned temperature range since the surface of the manganese oxide particles becomes smooth.

Further, after the above-mentioned particle growth heat treatment step and before the above-mentioned calcination step, a reserve material containing at least the first preliminary mixture after the particle growth heat treatment among the materials constituting the calcination mixture and containing no lithium compound is used. A mixture (hereinafter, also referred to as “second premix”) is prepared, and the second premix is usually less than 900 ° C, preferably 200 to 800 ° C, more preferably 400 to 800 ° C.
When heat treatment is performed at 700 ° C. for a predetermined time (hereinafter, also referred to as “phase change heat treatment”), the manganese oxide in the second preliminary mixture is changed from trimanganese tetroxide having a spinel structure to trioxide having a scandium oxide structure. It is preferable because the phase transition to dimanganese occurs.

The lithium-manganese composite oxide according to the present invention
The powder has a crystal structure substantially AB_TwoO _Four(A and B are metal
The element O represents an oxygen atom. ) With spinel structure
Usually, Li is tetrahedral as element A in the above formula.
Site surrounded by oxygen (hereinafter also referred to as “A site”)
U. ), And Mn and Me are octahedral as B elements
Sites surrounded by six oxygens (hereinafter also referred to as "B sites")
Say. ). Also, trimanganese tetroxide Mn_ThreeO
_FourIs a spine in which Mn exists in both the A and B sites.
It has a ru-shaped structure. For this reason, trimanganese tetroxide
When baked together with a lithium compound, Li becomes trimanganese tetroxide
Not only Mn of A site but also Mn of B site
Lithium man
The gun complex oxide has a lower L than that represented by the general formula (1).
i may be excessive. Also, Li is not excessive
When both Mn enters the A site and Li and Mn enter the B site,
The resulting lithium manganese composite oxide powder is
Extremely low battery performance even when used as a positive electrode active material for secondary batteries
It is not preferable because it becomes difficult. On the other hand, dimanganese trioxide
Mn_TwoO_ThreeHas a scandium oxide type structure,
The above cation exchange reaction even when calcined with lithium compound
Does not occur, and Li, Mn and Me are lithium manganese complex acids.
According to their respective stability in the spinel structure
The resulting lithium manganese complex
The composite oxide is represented by the general formula (1). others
For sintering together with lithium compound
Before scanning, trimanganese tetroxide with spinel structure
Phase transition to dimanganese trioxide with indium-type structure
And the target lithium man represented by the general formula (1)
It is preferable because a gun complex oxide can be easily obtained.

The second premix includes, specifically, manganese oxide alone or a mixture of manganese oxide with an aluminum compound, a zirconium compound, or a zinc compound. Further, as the aluminum compound, zirconium compound or zinc compound, any of the aluminum compound, the zirconium compound and the zinc compound which have been subjected to the particle growth heat treatment in the first preliminary mixture, or the compounds which have been incorporated in the second preliminary mixture for the first time may be used. Note that if the mixture containing the lithium compound is subjected to the phase transition heat treatment, a lithium manganese composite oxide may be generated. Therefore, the lithium compound is not included in the second preliminary mixture. When the second preliminary mixture is mixed with at least a lithium compound and, if necessary, an aluminum compound, a zirconium compound or a zinc compound after the phase transition heat treatment, the mixture for firing can be obtained.

Incidentally, the processing temperature of the phase transition heat treatment is 200
If the temperature is lower than ℃, it takes a long time for the phase transition from trimanganese tetroxide to dimanganese trioxide, which is not industrially advantageous. On the other hand, if the temperature exceeds 900 ° C., phase transition to dimanganese trioxide tends to be difficult to occur, which is not preferable. The processing time of the phase transition heat treatment is usually 3 to 24 hours, preferably 5 to 12 hours. The phase transition from trimanganese tetroxide to dimanganese trioxide can be confirmed by an X-ray diffraction method. be able to. In addition, when the phase change heat treatment is performed on trimanganese tetroxide having appropriately grown particles, it is preferable to supply sufficient oxygen to the particles by means of grinding or the like after cooling in advance. By the above-mentioned phase transition heat treatment, dimanganese trioxide has an average particle diameter of 5 to 3 measured using a laser particle size distribution analyzer.
0 μm, preferably 7-15 μm, and substantially 1 μm
It has a sharp particle size distribution with no particles below m.

Hereinafter, examples of the method for producing the intermediate lithium manganese composite oxide will be described according to the materials and the processing steps.
This will be described in detail with reference to (1) to (9).

(1) A method in which a manganese compound and a lithium compound are mixed and fired at 900 ° C. or higher. In the method, by setting the firing temperature to 900 ° C. or more,
The firing mixture comprising a manganese compound and a lithium compound is subjected to a particle growth heat treatment simultaneously with firing to obtain a lithium-manganese composite oxide. This method is preferable because the particle size distribution of the obtained intermediate lithium manganese composite oxide can be sharpened without performing the particle growth heat treatment as a separate step.

(2) A method in which a manganese compound, a lithium compound, an aluminum compound, a zirconium compound or a zinc compound are mixed and fired at 900 ° C. or higher. In the method, by setting the firing temperature to 900 ° C. or more,
A manganese compound, a lithium compound, an aluminum compound, a zirconium compound or a zirconium compound or a zirconium compound or zinc compound is subjected to particle growth heat treatment at the same time as firing, and manganese is replaced with aluminum, zirconium or zinc. Gain.
This method is preferable because the particle size distribution of the obtained intermediate lithium manganese composite oxide can be sharpened without performing the particle growth heat treatment as a separate step.

(3) A method in which a manganese compound is heat-treated at 900 ° C. or higher to obtain a manganese oxide, and the manganese oxide and a lithium compound are mixed and fired. The method comprises subjecting a first preliminary mixture composed of a manganese compound to a particle growth heating treatment, and then calcining the resultant calcining mixture composed of a manganese oxide and a lithium compound to obtain a lithium-manganese composite oxide. It is. In this method, since the particle growth heat treatment and the calcination are performed separately, the particle size distribution of the intermediate lithium manganese composite oxide obtained by the particle growth heat treatment can be sharpened, and moisture and hydroxyl groups on the particle surface and inside are removed. It is preferable because fine particles of 1 μm or less can be removed, and the conditions for the particle growth heat treatment and the baking treatment can be appropriately adjusted.

(4) A method in which a manganese compound is heat-treated at 900 ° C. or higher to obtain a manganese oxide, and the manganese oxide, a lithium compound, an aluminum compound, a zirconium compound or a zinc compound are mixed and fired. The method comprises subjecting a first preliminary mixture comprising a manganese compound to a particle growth heat treatment, followed by firing a firing mixture comprising a manganese oxide and a lithium compound and an aluminum compound, a zirconium compound or a zinc compound. To obtain a lithium manganese composite oxide in which manganese is partially substituted by aluminum, zirconium or zinc. In this method, since the particle growth heat treatment and the calcination are performed separately, the particle size distribution of the intermediate lithium manganese composite oxide obtained by the particle growth heat treatment can be sharpened, and moisture and hydroxyl groups on the particle surface and inside are removed. ,
Fine particles having a particle size of 1 μm or less can be removed, and the conditions of the particle growth heat treatment and the baking treatment can be appropriately adjusted, which is preferable.

(5) A method in which a manganese compound and an aluminum compound, a zirconium compound or a zinc compound are heat-treated at 900 ° C. or more, and the obtained mixture is mixed with a lithium compound and fired. The method comprises subjecting a first preliminary mixture comprising a manganese compound and an aluminum compound, a zirconium compound or a zinc compound to a particle growth heat treatment, and then calcining a calcining mixture comprising the resulting mixture and a lithium compound, This is to obtain a lithium manganese composite oxide in which manganese is partially substituted with aluminum, zirconium or zinc.
In this method, since the particle growth heat treatment and the baking are performed separately, the particle size distribution of the intermediate lithium manganese composite oxide obtained by the particle growth heat treatment can be sharpened, and moisture and hydroxyl groups on the particle surface and inside are removed. , 1μ
m or less, and the conditions for the particle growth heat treatment and the baking treatment can be appropriately adjusted, which is preferable. In addition, the method, aluminum during the growth of manganese oxide particles, a substitution element with manganese such as zirconium or zinc is previously taken into the manganese oxide particles,
It is preferable because these substitution elements can be uniformly substituted for manganese inside the lithium manganese composite oxide powder without being unevenly present on the surface of the lithium manganese composite oxide powder according to the present invention.

(6) A method in which a manganese compound is heat-treated at 900 ° C. or higher, and further heat-treated at a temperature lower than 900 ° C., and the obtained manganese oxide and a lithium compound are mixed and fired. The method comprises subjecting a first premix made of a manganese compound to a particle growth heat treatment, further performing a phase transition heat treatment to the second premix made of a manganese oxide,
The obtained mixture for firing composed of a manganese oxide and a lithium compound is fired to obtain a lithium-manganese composite oxide. In this method, since the particle growth heat treatment, the phase transition heat treatment, and the calcination are performed, the particle size distribution of the intermediate lithium manganese composite oxide obtained by the particle growth heat treatment can be sharpened. It is preferable because a stable spinel-type lithium manganese composite oxide coordinated to four coordinates (A site) can be obtained.

(7) The manganese compound is heat-treated at 900 ° C. or higher, and further heat-treated at a temperature lower than 900 ° C., and the obtained manganese oxide, lithium compound, aluminum compound, zirconium compound or zinc compound are mixed, How to fire. The method comprises subjecting a first premix made of a manganese compound to a particle growth heat treatment, further performing a phase transition heat treatment to the second premix made of a manganese oxide,
The obtained manganese oxide and a lithium compound and an aluminum compound, a firing mixture comprising a zirconium compound or a zinc compound is fired, and manganese is aluminum,
This is to obtain a lithium manganese composite oxide partially substituted with zirconium or zinc. In this method, since the particle growth heat treatment, the phase transition heat treatment, and the calcination are performed, the particle size distribution of the intermediate lithium manganese composite oxide obtained by the particle growth heat treatment can be sharpened. It is preferable because a stable spinel-type lithium manganese composite oxide coordinated to four coordinates (A site) can be obtained.

(8) A manganese compound and an aluminum compound, a zirconium compound or a zinc compound are heat-treated at 900 ° C. or higher, and further heat-treated at a temperature lower than 900 ° C., and the obtained mixture is mixed with a lithium compound. how to. The method comprises subjecting a first premix comprising a manganese compound and an aluminum compound, a zirconium compound or a zinc compound to a particle growth heat treatment, and further subjecting a second premix comprising the resulting mixture to a phase transition heat treatment. And firing the firing mixture comprising the obtained mixture and a lithium compound to obtain a lithium-manganese composite oxide in which manganese is partially substituted with aluminum, zirconium or zinc. In this method, since the particle growth heat treatment, the phase transition heat treatment, and the calcination are performed, the particle size distribution of the intermediate lithium manganese composite oxide obtained by the particle growth heat treatment can be sharpened. It is preferable because a stable spinel-type lithium manganese composite oxide coordinated to four coordinates (A site) can be obtained.

(9) The manganese compound and the aluminum compound are heat-treated at 900 ° C. or higher, and further heat-treated at a temperature lower than 900 ° C., and the obtained mixture, a lithium compound, a zirconium compound or a zinc compound are mixed and fired. Method. The method comprises subjecting a first premix comprising a manganese compound and an aluminum compound to a particle growth heat treatment, further subjecting a second premix consisting of the resulting mixture to a phase transition heat treatment, and then subjecting the resulting mixture to a heat treatment. A firing mixture comprising a lithium compound and a zirconium compound or a zinc compound is fired to obtain a lithium-manganese composite oxide in which manganese is partially replaced by aluminum and zirconium or zinc. In the method, since the particle growth heat treatment, the phase transition heat treatment, and the calcination are performed, the particle size distribution of the intermediate lithium manganese composite oxide obtained by the particle growth heat treatment can be sharpened, and the aluminum compound is used during the particle growth heat treatment. After the phase transition heat treatment, a zirconium compound or a zinc compound is blended, and the lithium atom is four-coordinated (A
This is preferable because a stable spinel-type lithium manganese composite oxide coordinated to (site) can be obtained.

Of the above-mentioned production methods (1) to (9), particularly preferred specific examples will be described in more detail, but the production method is not limited thereto. In the following, a manganese compound is represented by A, A ', A ", a' or a", a lithium compound is represented by B, and an aluminum compound, a zirconium compound or a zinc compound is represented by C, C 'or c'. A is a manganese compound which has not been subjected to any heat treatment, A 'is a manganese oxide after A is subjected to a particle growth heat treatment once, and A''isA' after a particle growth heat treatment is performed once to A ' That is, manganese oxide after A was subjected to particle growth heat treatment twice, a ′ was manganese oxide after A ′ was subjected to one phase transition heat treatment, and a ″ was phase transition to A ″ Manganese oxide after one heat treatment, B is a lithium compound without any heat treatment, C is an aluminum compound, zirconium compound or zinc compound without any heat treatment, C 'is C An aluminum compound, a zirconium compound or a zinc compound after a single grain growth heat treatment, and an aluminum compound, a zirconium compound or a zinc compound after a single phase transition heat treatment to C ′. As described above, by mixing C when heat-treating A, A contained in C is mixed.
Although a Me component such as l, Zr or Zn may be taken into A ′, for convenience, those obtained by heating the raw material X are denoted as X ′, X ″, etc. Are represented as x ', x'', etc., respectively.

<Specific Example of Production Method (2)> (1) A, B and C are mixed and mixed at 900 ° C.
A method of baking simultaneously with the particle growth heat treatment for 24 hours.

<Specific Example of Production Method (4)> (2) A is subjected to a particle growth heat treatment at 900 ° C. or higher for 0.5 to 24 hours to form A ′, and then A ′, B and C are mixed. ,
A method of baking at 500 to 1100 ° C. for 1 to 24 hours. (3) Heat treatment of A in the same manner as (2) for particle growth (first time)
A 'is mixed with A' which has not been heated and then subjected to particle growth heat treatment (second time) in the same manner as the first time to form a mixture of A '' and A '. And C are mixed to form a mixture of A ″, A ′, B and C, and then fired in the same manner as in (2). In this method, C is mixed with A ′ and A at the time of the second particle growth heat treatment to obtain A ′, A and C, which are subjected to the particle growth heat treatment (second time) to A ″, After forming a mixture of A 'and C', B may be further added to form a mixture of A '', A ', B and C', followed by firing similarly.

<Specific Example of Production Method (7)> (4) After A was subjected to particle growth heat treatment at 900 ° C. or higher for 0.5 to 24 hours to form A ′, A ′ was further added to 200 to 900
After a phase transition heat treatment at a temperature lower than 3 ° C. for 3 to 24 hours to obtain a ′, a ′ and B are mixed, and then mixed at 500 to 1100 ° C. for 1 to 2 hours.
A method of firing for 4 hours. In this method, C is changed to A
After mixing, the mixture is subjected to a particle growth heat treatment to form a mixture of A 'and C', and further a phase transition heat treatment at 200 to less than 900 DEG C. to form a mixture of a 'and c'. May be added to form a mixture of a ', B and c', followed by firing. (5) Heat treatment of particle growth in the same manner as (4) for A (first time)
After A ′, the A ′ and the untreated A were mixed and subjected to a particle growth heat treatment (second time) in the same manner as the first time to form a mixture of A ′ and A ″. A phase transition heat treatment at a temperature lower than 〜900 ° C. for 3 to 24 hours to form a mixture of a ′ and a ″, and mixing B and C into the mixture to obtain a ′,
A method in which a mixture of a '', B, and C is used, followed by firing. In this method, before the second heat treatment, C is mixed with A and A 'to form A, A' and C, which are subjected to a particle growth heat treatment (second time) and subjected to A 'and A''. And a mixture of C ′ and 200-900
A ′, a ″
And c ′, and B is added to a ′,
After forming a mixture of a '', B and c ', the mixture may be similarly baked.

In the above-mentioned firing method, the aluminum compound, zirconium compound or zinc compound may be used alone or at any time before or during firing of particle growth heat treatment, phase transition heat treatment, or a mixture thereof. More than one species can be added simultaneously.

In the above methods (3) and (5), untreated A having a small particle size is added to A ′ having a large particle size by heating once, and mixed. 'And A
The particle diameter of the lithium manganese composite oxide to be calcined can be adjusted by changing the compounding ratio of the above.

In the method for producing a lithium-manganese composite oxide according to the above methods (1) to (5), a mixture of a manganese compound and an aluminum compound, a zirconium compound or a zinc compound is subjected to particle growth heat treatment before firing, or After phase growth heat treatment after particle growth heat treatment, then, when a lithium compound is added and calcination is performed, aluminum, zirconium or zinc having a uniform composition in which manganese sites of the lithium manganese composite oxide are uniformly substituted. Is preferred because it is easily obtained.

In the above methods (1) to (5), first, a lithium manganese composite oxide and B are added and mixed so that the lithium composition ratio is larger than x in the above formula (1). When the lithium manganese composite oxide that satisfies the above formula (1) is generated by firing again after the oxide is generated, moderate oxygen defects are generated in the lithium manganese composite oxide, and thus the obtained lithium manganese composite oxide is obtained. When the powder is in contact with the non-aqueous electrolyte of the lithium secondary battery, the amount of Mn ions eluted is smaller, and when used as the positive electrode active material of the lithium secondary battery, the battery performance such as capacity retention and storage characteristics is more improved. Can be higher.

The lithium manganese composite oxide according to the present invention can be used as a positive electrode active material of a lithium secondary battery.

The positive electrode active material for a lithium secondary battery according to the present invention contains the above-mentioned lithium manganese composite oxide powder. The positive electrode active material is one raw material of a positive electrode mixture for a lithium secondary battery described later, that is, a mixture of a positive electrode active material, a conductive agent, a binder, and, if necessary, a filler.
Since the lithium secondary battery positive electrode active material according to the present invention is composed of the lithium manganese composite oxide powder, it is easy to knead when preparing a positive electrode mixture by mixing with other raw materials, and also obtained. Coatability when applying the positive electrode mixture to the positive electrode current collector is facilitated.

The lithium secondary battery according to the present invention uses the above-mentioned positive electrode active material for a lithium secondary battery.
It comprises a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt. The positive electrode is formed, for example, by applying a positive electrode mixture on a positive electrode current collector and drying the positive electrode mixture. Consists of In the lithium secondary battery according to the present invention, since the particle size distribution of the lithium secondary battery positive electrode active material is sharp, the lithium manganese composite oxide powder as the positive electrode active material is uniformly applied to the positive electrode. Therefore, current is not locally concentrated on the positive electrode, and the capacity retention rate of the discharge capacity is high.

The positive electrode current collector is not particularly limited as long as it is an electron conductor that does not cause a chemical change in the constituted battery. For example, stainless steel, nickel, aluminum, titanium, calcined carbon, aluminum, Examples thereof include those obtained by surface-treating carbon, nickel, titanium, and silver on the surface of stainless steel.

Examples of the conductive agent include conductive materials such as graphite such as natural graphite and artificial graphite, carbon black, acetylene black, carbon fiber, metal and nickel powder. Examples of the natural graphite include scale graphite , Flaky graphite and earthy graphite. These are one or two
It can be used in combination of more than one kind. The mixing ratio of the conductive agent is 1 to 50% by weight, preferably 2 to 50% by weight in the positive electrode mixture.
30% by weight.

As the binder, for example, polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl pyrrolidone, ethylene-propylene-diene terpolymer (EPD)
M), sulfonated EPDM, styrene butadiene rubber,
Examples thereof include polysaccharides such as fluorine rubber and polyethylene oxide, thermoplastic resins, and polymers having rubber elasticity. These can be used alone or in combination of two or more. The mixing ratio of the binder is 2 to 30% by weight, preferably 5 to 15% by weight in the positive electrode mixture.

The filler suppresses volume expansion and the like of the positive electrode in the positive electrode mixture, and is added as necessary. As the filler, any fibrous material that does not cause a chemical change in the configured battery can be used. For example, olefin-based polymers such as polypropylene and polyethylene, and fibers such as glass and carbon are used.
The amount of the filler added is not particularly limited, but in the positive electrode mixture,
0-30% by weight is preferred.

The negative electrode is formed by coating a negative electrode material on a negative electrode current collector and drying the material. The negative electrode current collector is not particularly limited as long as it is an electronic conductor that does not cause a chemical change in the configured battery, for example, stainless steel,
Examples thereof include nickel, copper, titanium, aluminum, calcined carbon, copper and stainless steel having a surface treated with carbon, nickel, titanium, and silver, and an aluminum-cadmium alloy.

The negative electrode material is not particularly limited, but examples thereof include a carbonaceous material, a metal composite oxide, lithium metal, and a lithium alloy. Examples of the carbonaceous material include a non-graphitizable carbon material and a graphite-based carbon material. Examples of the metal composite oxide include Sn
_p M ¹¹ _-p M ² _{q Or} (where M ¹ is Mn, Fe, Pb
And at least one element selected from Ge and M ²
l, B, P, Si, at least one element selected from the first, second, and third groups of the periodic table and a halogen element;
<P ≦ 1, 1 ≦ q ≦ 3, 1 ≦ r ≦ 8. And the like.

As the separator, an insulating thin film having a high ion permeability and a predetermined mechanical strength is used. Sheets and nonwoven fabrics made of olefin polymers such as polypropylene, glass fiber, polyethylene, or the like are used because of their organic solvent resistance and hydrophobicity. The pore diameter of the separator may be any range generally useful for batteries, for example, 0.01 to 10
μm. The thickness of the separator may be within the range for general batteries, and is, for example, 5 to 300 μm.
When a solid electrolyte such as a polymer is used as an electrolyte described later, the solid electrolyte may also serve as a separator. Further, a compound such as pyridine, triethyl phosphite, and triethanolamine may be added to the electrolyte for the purpose of improving the discharge and charge / discharge characteristics.

The non-aqueous electrolyte containing a lithium salt is composed of a non-aqueous electrolyte and a lithium salt. As the non-aqueous electrolyte, a non-aqueous electrolyte or an organic solid electrolyte is used. Examples of the non-aqueous electrolyte include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane,
Tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane,
Formamide, dimethylformamide, dioxolan,
Acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivative, sulfolane, 3-methyl-2-oxazodinone, propylene carbonate derivative, tetrahydrofuran derivative, diethyl ether, 1,3-propane sultone, etc. And a mixture of two or more of the aprotic organic solvents described above.

As the organic solid electrolyte, for example, polyether
Tylene derivative or polymer containing it, polypropylene
Oxide derivatives or polymers containing the same, phosphates
Terpolymers and the like. As the lithium salt,
What is dissolved in the non-aqueous electrolyte is used, for example, Li
ClO_Four, LiBF_Four, LiPF₆, LiCF_ThreeS
O _Three, LiCF_ThreeCO_Two, LiAsF₆, LiSb
F₆, LiB_TenCl_Ten, LiAlCl_Four, Chloroborane
Lithium, lithium lower aliphatic carboxylate, tetraphenyl
Salts such as lithium borate or a mixture of two or more thereof are listed.
I can do it.

One or more compounds shown below can be added to the non-aqueous electrolyte for the purpose of improving charge / discharge characteristics and flame retardancy. For example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexaphosphoric triamide, nitrobenzene derivative, sulfur, quinone imine dye, N-substituted oxazolidinone and N, N-substituted imidazolidine, ethylene glycol dialkyl ether , Ammonium salt, polyethylene glycol, pyrrole, 2
Methoxyethanol, aluminum trichloride, conductive polymer electrode active material monomer, triethylenephosphonamide, trialkylphosphine, morpholine, aryl compound having a carbonyl group, hexamethylphosphoric triamide and 4-alkylmorpholine, Examples include cyclic tertiary amines, oils, phosphonium salts and tertiary sulfonium salts, phosphazenes, carbonates and the like.

The shape of the battery can be applied to any of buttons, sheets, cylinders, corners and the like. The use of the lithium secondary battery according to the present invention is not particularly limited. And consumer electronic devices such as game devices.

[0068]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
Was heated at 1000 ° C. for 12 hours, cooled, and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Then, 4.48 g of lithium carbonate having an average particle size of 3.0 μm was added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible. I got Next, the lithium manganese composite oxide was pulverized using a coffee mill to obtain a pulverized lithium manganese composite oxide having an average particle diameter of 7.5 μm and a BET specific surface area of 0.98 m ² / g (intermediate lithium manganese composite oxide). ) Got. Thereafter, the intermediate lithium manganese composite oxide was subjected to a heat treatment at 600 ° C. for 5 hours.
X-ray diffraction confirmed that the obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide were both LiMn ₂ O ₄ having a spinel structure. Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 2 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm were added and mixed, placed in an alumina crucible, and fired at 900 ° C. for 12 hours in an air atmosphere to obtain a lithium-manganese composite oxide. Next, the lithium manganese composite oxide was pulverized using a coffee mill to obtain an average particle diameter of 4.6 μm, BET
A pulverized lithium manganese composite oxide (intermediate lithium manganese composite oxide) having a specific surface area of 1.77 m ² / g was obtained.
Then, the intermediate lithium manganese composite oxide was added to 600
Heat treatment was performed at 5 ° C. for 5 hours. The obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide are both Li having a spinel structure by X-ray diffraction.
It was confirmed to be Mn ₂ O ₄ . Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 3 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And aluminum hydroxide 1.11 having an average particle size of 1.0 μm
g, heat-treated at 1000 ° C. for 12 hours, cooled,
Lightly crushed. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, the heat-treated electrolytically synthesized manganese dioxide has an average particle size of 3.
4.48 g of lithium carbonate of 0 μm was added and mixed, put into an alumina crucible, and calcined at 900 ° C. for 12 hours in an air atmosphere to obtain a lithium manganese composite oxide. Next, the lithium manganese composite oxide was pulverized using a coffee mill to have an average particle diameter of 6.8 μm and a BET specific surface area of 0.92.
A pulverized product of m ² / g lithium manganese composite oxide (intermediate lithium manganese composite oxide) was obtained. Thereafter, the intermediate lithium manganese composite oxide was subjected to a heat treatment at 600 ° C. for 5 hours. The obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide were both Li _1.05 Mn _1.875 A having a spinel structure by X-ray diffraction.
l _0.125 O ₄ . Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 4 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium oxide having an average particle diameter of 1.2 μm (Zr
O ₂₎ were mixed 0.26g was 12 hours of heat treatment at 1000 ° C., then cooled and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Then, 4.48 g of lithium carbonate having an average particle size of 3.0 μm was added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible. I got Next, the lithium manganese composite oxide is pulverized using a coffee mill to obtain a pulverized lithium manganese composite oxide having an average particle diameter of 6.3 μm and a BET specific surface area of 0.91 m ² / g (intermediate lithium manganese composite oxide). ) Got. Thereafter, the intermediate lithium manganese composite oxide was heated to 600 ° C.
For 5 hours. The obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide are both Li having a spinel structure by X-ray diffraction.
It was confirmed that _{1.05 Mn 1.98 Zr 0. 02 O 4} . Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 5 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium hydroxide (Zr) having an average particle size of 1.7 μm
(OH)_Four) Mix at 0.30g and 1000 ℃ for 12 hours
Heated, cooled and lightly ground. Next, the heating process
Heated manganese dioxide at 650 ° C for 8 hours
Processed. Next, the heat-treated electrolytically synthesized man dioxide
4.48 g of lithium carbonate having an average particle size of 3.0 μm was added to the gun.
And mixed in an alumina crucible.
Lithium manganese composite oxidation by firing in air atmosphere for hours
I got something. Next, the lithium manganese composite oxide is
Pulverized using a heat mill, average particle size 6.9 μm, B
ET specific surface area 0.92m^Two/ g lithium manganese composite oxidation
Pulverized product (intermediate lithium manganese composite oxide)
Was. Then, the intermediate lithium manganese composite oxide was added to 6
Heat treatment was performed at 00 ° C. for 5 hours. Lithium manga obtained
Composite oxide powder and the intermediate lithium manganese composite
Both oxides have a spinel structure by X-ray diffraction
Li_1.05Mn _1.98Zr_0.02O_FourIs confirmed to be
Was. Table 1 shows the physical properties of the lithium manganese composite oxide powder.
Shown in

Example 6 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium acetylacetonate (Zr (CH ₃ C
OCHCOCH ₃ ) ₄ ) 1.03 g and mixed at 1000 ° C.
For 12 hours, cooled and crushed lightly. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C.
For 8 hours. Next, 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm was added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible.
Calcination was performed at 00 ° C. for 12 hours in an air atmosphere to obtain a lithium manganese composite oxide. Next, the lithium manganese composite oxide was pulverized using a coffee mill to obtain a pulverized lithium manganese composite oxide having an average particle diameter of 6.8 μm and a BET specific surface area of 0.94 m ² / g (intermediate lithium manganese composite oxide). ) Got. Thereafter, the intermediate lithium manganese composite oxide was subjected to a heat treatment at 600 ° C. for 5 hours. Both the obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide were confirmed to be Li _1.05 Mn _1.98 Zr _0.02 O ₄ having a spinel structure by X-ray diffraction. Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 7 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium oxide having an average particle diameter of 1.2 μm (Zr
0.26 g of O ₂ ) and 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm were added and mixed, and placed in an alumina crucible.
Calcination was performed at 00 ° C. for 12 hours in an air atmosphere to obtain a lithium manganese composite oxide. Next, the lithium manganese composite oxide is pulverized using a coffee mill to obtain a pulverized lithium manganese composite oxide having an average particle diameter of 4.2 μm and a BET specific surface area of 1.53 m ² / g (intermediate lithium manganese composite oxide). ) Got. Thereafter, the intermediate lithium manganese composite oxide was subjected to a heat treatment at 600 ° C. for 5 hours. Both the obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide were confirmed to be Li _1.05 Mn _1.98 Zr _0.02 O ₄ having a spinel structure by X-ray diffraction. Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 8 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium oxide having an average particle diameter of 1.2 μm (Zr
O_Two) 0.26g and 1.0μm average particle size hydroxylation
1.11 g of aluminum mixed at 1000 ° C for 12 hours
Heated, cooled and lightly ground. Next, the heating process
Heated manganese dioxide at 650 ° C for 8 hours
Processed. Next, the heat-treated electrolytically synthesized man dioxide
4.48 g of lithium carbonate having an average particle size of 3.0 μm was added to the gun.
And mixed in an alumina crucible.
Lithium manganese composite oxidation by firing in air atmosphere for hours
I got something. Next, the lithium manganese composite oxide is
Pulverized using a heat mill, average particle size 6.8 μm, B
ET specific surface area 0.88m^Two/ g lithium manganese composite oxidation
Pulverized product (intermediate lithium manganese composite oxide)
Was. Then, the intermediate lithium manganese composite oxide was added to 6
Heat treatment was performed at 00 ° C. for 5 hours. Lithium manga obtained
Composite oxide powder and the intermediate lithium manganese composite
Both oxides have a spinel structure by X-ray diffraction
Li_1.05Mn_1.855Al_0.125Zr_0.02O _FourBeing
Was confirmed. Various lithium manganese composite oxide powders
The properties are shown in Table 1.

Example 9 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And aluminum hydroxide 1.11 having an average particle size of 1.0 μm
g, heat-treated at 1000 ° C. for 12 hours, cooled,
Lightly crushed. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, the heat-treated electrolytically synthesized manganese dioxide has an average particle size of 3.
4.48 g of 0 μm lithium carbonate and an average particle size of 1.2 μm
0.26 g of zirconium oxide (ZrO ₂ ) was added and mixed, placed in an alumina crucible, and fired at 900 ° C. for 12 hours in an air atmosphere to obtain a lithium-manganese composite oxide. Next, the lithium manganese composite oxide is pulverized using a coffee mill to obtain a pulverized lithium manganese composite oxide having an average particle diameter of 6.4 μm and a BET specific surface area of 0.90 m ² / g (intermediate lithium manganese composite oxide). ) Got. Thereafter, the intermediate lithium manganese composite oxide was heated to 600 ° C.
For 5 hours. The obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide are both Li having a spinel structure by X-ray diffraction.
_1.05 Mn _1.855 Al _0.125 Zr _0.02 O ₄ was confirmed. Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 10 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
Was heated at 1000 ° C. for 12 hours, cooled, and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm and 0.26 g of zirconium oxide (ZrO ₂ ) having an average particle diameter of 1.2 μm were added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible. Calcination was performed at 900 ° C. for 12 hours in an air atmosphere to obtain a lithium manganese composite oxide. Next, the lithium manganese composite oxide was pulverized using a coffee mill to obtain a pulverized lithium manganese composite oxide having an average particle diameter of 7.2 μm and a BET specific surface area of 0.97 m ² / g (intermediate lithium manganese composite oxide). ) Got. Thereafter, the intermediate lithium manganese composite oxide was subjected to a heat treatment at 600 ° C. for 5 hours. The obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide are both Li having a spinel structure by X-ray diffraction.
_1.05 Mn _1.98 Zr _0.02 O ₄ was confirmed. Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Example 11 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And 0.175 g of zinc oxide (ZnO) having an average particle size of 3 μm
Was mixed, heated at 1000 ° C. for 12 hours, cooled, and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, the heat-treated electrolytically synthesized manganese dioxide had an average particle size of 3.0.
4.48 g of lithium carbonate having a particle size of 4.mu.m was added and mixed, put into an alumina crucible, and calcined at 900 DEG C. for 12 hours in an air atmosphere to obtain a lithium manganese composite oxide. Next, the lithium manganese composite oxide was pulverized using a coffee mill to have an average particle size of 7.4 μm and a BET specific surface area of 0.77 m ^2.
/ g of lithium manganese composite oxide (intermediate lithium manganese composite oxide) was obtained. Thereafter, the intermediate lithium manganese composite oxide was subjected to a heat treatment at 650 ° C. for 5 hours. The obtained lithium manganese composite oxide powder and the intermediate lithium manganese composite oxide are both Li _1.05 Mn _1.98 Zn having a spinel structure by X-ray diffraction.
It was confirmed to be _0.02 O ₄ . Table 1 shows various physical property values of the lithium manganese composite oxide powder.

Comparative Example 1 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
Was heated at 1000 ° C. for 12 hours, cooled, and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm was added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible and fired at 900 ° C. for 12 hours in an air atmosphere.
X-ray diffraction confirmed that the obtained lithium manganese composite oxide was LiMn ₂ O ₄ having a spinel structure. Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 2 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And 4.48 g of lithium carbonate having an average particle size of 3.0 μm were added, mixed and placed in an alumina crucible, and fired at 900 ° C. for 12 hours in an air atmosphere. The obtained lithium manganese composite oxide is obtained by X-ray diffraction and has a spinel structure.
It was confirmed to be iMn ₂ O ₄ . Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 3 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And aluminum hydroxide 1.11 having an average particle size of 1.0 μm
g, heat-treated at 1000 ° C. for 12 hours, cooled,
Lightly crushed. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, the heat-treated electrolytically synthesized manganese dioxide has an average particle size of 3.
4.48 g of lithium carbonate of 0 μm was added and mixed, put into an alumina crucible, and fired at 900 ° C. for 12 hours in an air atmosphere. The obtained lithium manganese composite oxide was Li _1.05 Mn _1.875 having a spinel structure by X-ray diffraction.
It was confirmed to be Al _0.125 O ₄ . Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 4 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium oxide having an average particle diameter of 1.2 μm (Zr
O ₂₎ were mixed 0.26g was 12 hours of heat treatment at 1000 ° C., then cooled and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm was added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible and fired at 900 ° C. for 12 hours in an air atmosphere. The obtained lithium-manganese composite oxide is obtained by Li-X having a spinel structure by X-ray diffraction.
_1.05 Mn _1.98 Zr _0.02 O ₄ was confirmed. Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 5 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And 0.30 of zirconium hydroxide having an average particle size of 1.7 μm.
g, heat-treated at 1000 ° C. for 12 hours, cooled,
Lightly crushed. Next, the heat-treated electrolytically synthesized dioxide
Manganese was heated at 650 ° C. for 8 hours. Then,
2. Average particle size of heat-treated electrolytically synthesized manganese dioxide
Add 4.48g of 0μm lithium carbonate and mix.
Put in a crucible and bake at 900 ° C for 12 hours in air atmosphere
Done. The obtained lithium manganese composite oxide is subjected to X-ray
Li having a spinel structure by diffraction_1.05Mn_1.98Z
r _0.02O_FourWas confirmed. Lithium manganese
Table 1 shows various physical property values of the composite oxide.

Comparative Example 6 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium acetylacetonate (1.03 g) were mixed, heated at 1000 ° C. for 12 hours, cooled, and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm was added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible and fired at 900 ° C. for 12 hours in an air atmosphere.
The obtained lithium manganese composite oxide was Li _1.05 Mn _1.98 Zr _0.02 O having a spinel structure by X-ray diffraction.
It was confirmed to be ₄ . Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 7 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium oxide having an average particle diameter of 1.2 μm (Zr
0.26 g of O ₂ ) and 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm were added and mixed, and placed in an alumina crucible.
Calcination was performed at 00 ° C. for 12 hours in an air atmosphere. X-ray diffraction confirmed that the obtained lithium manganese composite oxide was Li _1.05 Mn _1.98 Zr _0.02 O ₄ having a spinel structure. Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 8 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And zirconium oxide having an average particle diameter of 1.2 μm (Zr
0.26 g of O ₂ ) and 1.11 g of aluminum hydroxide having an average particle diameter of 1.0 μm were mixed, heat-treated at 1000 ° C. for 12 hours, cooled, and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Then, 4.48 g of lithium carbonate having an average particle size of 3.0 μm was added to the heat-treated electrolytically synthesized manganese dioxide.
And mixed in an alumina crucible.
Calcination was performed in an air atmosphere for hours. The resulting lithium-manganese composite oxide was confirmed by X-ray diffraction is a _{Li 1.05 Mn 1.855 Al 0.12 5 Zr} 0.02 O 4 having a spinel structure. Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 9 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
And aluminum hydroxide 1.11 having an average particle size of 1.0 μm
g, heat-treated at 1000 ° C. for 12 hours, cooled,
Lightly crushed. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, the heat-treated electrolytically synthesized manganese dioxide has an average particle size of 3.
4.48 g of 0 μm lithium carbonate and an average particle size of 1.2 μm
Then, 0.26 g of zirconium oxide (ZrO ₂ ) was added and mixed, placed in an alumina crucible, and fired at 900 ° C. for 12 hours in an air atmosphere. The obtained lithium-manganese composite oxide is obtained by Li-X having a spinel structure by X-ray diffraction.
_1.05 Mn _1.855 Al _0.125 Zr _0.02 O ₄ was confirmed. Table 1 shows properties of the lithium manganese composite oxide.

Comparative Example 10 20 g of electrolytically synthesized manganese dioxide having an average particle size of 3.2 μm
Was heated at 1000 ° C. for 12 hours, cooled, and lightly ground. Next, the heat-treated electrolytically synthesized manganese dioxide was heated at 650 ° C. for 8 hours. Next, 4.48 g of lithium carbonate having an average particle diameter of 3.0 μm and 0.26 g of zirconium oxide (ZrO ₂ ) having an average particle diameter of 1.2 μm were added to the heat-treated electrolytically synthesized manganese dioxide, and the mixture was placed in an alumina crucible. It was baked at 900 ° C. for 12 hours in an air atmosphere. The obtained lithium manganese composite oxide is
Li _1.05 Mn having a spinel structure by X-ray diffraction
_1.98 Zr _0.02 O ₄ was confirmed. Table 1 shows properties of the lithium manganese composite oxide.

<Mn Dissolution Test> 0.5 g of the sample obtained in Example 1 was vacuum-dried at 120 ° C. for 3 days. Then
A solution was prepared by dissolving LiPF ₆ at a concentration of 1 mol / L in a solution in which ethylene carbonate and dimethyl carbonate were mixed at a volume ratio of 1: 1, and 10 ml of the solution was added to 0.5 g of the sample and sealed. Next, the solution was allowed to stand at 60 ° C. for 96 hours in a sealed state, and then the solution was filtered.
g was collected, 10 ml of ethanol was added thereto, and the volume was further increased to 50 ml with ultrapure water. About the resulting solution
The Mn concentration was measured by the ICP method. The above operation was similarly performed on the samples obtained in Examples 2 to 11 and Comparative Examples 1 to 10. Table 1 shows the results.

[0091]

[Table 1]

From the results shown in Table 1, it can be seen that the lithium manganese composite oxide according to the present invention has a considerably reduced amount of Mn ions eluted.

<Evaluation of Battery Performance> (Preparation of Lithium Secondary Battery) A mixture of 70% by weight of the lithium-manganese composite oxide sample obtained in Example 1, 20% by weight of graphite powder, and 10% by weight of polyvinylidene fluoride was mixed. The mixture was dispersed in N-methyl-2-pyrrolidinone to prepare a kneaded paste. The kneaded paste was applied to an aluminum foil, dried, pressed, and punched into a disk having a diameter of 15 mm to obtain a positive electrode plate. Using this positive electrode plate, a lithium secondary battery was manufactured using each member such as a separator, a negative electrode, a current collector plate, a mounting bracket, an external terminal, and an electrolytic solution. For the negative electrode, carbon having a high degree of crystallinity was used, and the electrolyte was a 1: 1 mixture of ethyl methyl carbonate and ethylene carbonate.
A solution obtained by dissolving LiPF ₆ in 1 liter of the mixed solution was used. The obtained lithium secondary battery was operated at 50 ° C., and the initial discharge capacity and the capacity retention were measured as follows.

(Evaluation Method for Lithium Secondary Battery) Measurement of initial discharge capacity: 0.5 ° C. at 50 ° C.
After charging to 4.3 V at mA / cm ² , charge / discharge for discharging to 3.5 V was performed for one cycle, and the discharge capacity was measured. The discharge capacity in the first cycle was defined as the initial discharge capacity. Measurement of capacity retention ratio: The charge / discharge in the above measurement of the discharge capacity was performed for 20 cycles, and the capacity retention ratio was calculated by the following equation. Capacity maintenance ratio (%) = (discharge capacity at 20th cycle / discharge capacity at 1st cycle) × 100 The above operation is similarly performed on the samples obtained in Examples 2 to 10 and Comparative Examples 1 to 10. Was. Table 1 shows the results.

From the results shown in Table 1, the lithium secondary battery using the lithium-manganese composite oxide powder according to the present invention as a positive electrode active material has a reduced capacity retention ratio because manganese ion elution from the positive electrode active material is suppressed. Is high.

[0096]

As described above, the lithium manganese composite oxide powder according to the present invention has Mn even when it comes into contact with the electrolyte of a lithium secondary battery.
Low ion elution amount. In addition, a lithium secondary battery using the lithium manganese composite oxide powder as a positive electrode active material has an effect of increasing battery performance, particularly capacity retention and storage characteristics.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G048 AA04 AB05 AC06 AD04 AE05 5H029 AJ03 AJ04 AK03 AL03 AL06 AL07 AL12 AM02 AM03 AM04 AM05 AM07 AM16 CJ02 CJ08 HJ00 HJ02 HJ05 HJ07 HJ14 5H050 AA08 AA09 CB03 CA07 CB09 GA10 HA00 HA02 HA05 HA07 HA14

Claims (16)

[Claims] 1. The following general formula (1): Li _x Mn _2-y Me _y O _4-z (1) (where Me is Al, Zr or Zn, and x is 0 <x
<2.0, y takes a value of 0 ≦ y <0.6, and z takes a value of 0 ≦ z ≦ 2.0. ), Wherein the lithium manganese composite oxide powder is obtained by heat-treating a pulverized lithium manganese composite oxide represented by the above general formula (1) at 300 to 800 ° C. And a BET specific surface area of 0.1 to 2.0 m ² / g. 2. The pulverized lithium manganese composite oxide has an average particle diameter of 0.1 to 50 μm and a BET specific surface area of 0.1 to 2.0 m ² / g. Item 7. A lithium manganese composite oxide powder according to item 1. 3. The lithium manganese composite oxide powder according to claim 1, wherein the n value determined by Rosin-Rammler is 3.0 or more. 4. The following general formula (1): Li _x Mn _2-y Me _y O _4-z (1) (where Me is Al, Zr or Zn, and x is 0 <x
<2.0, y takes a value of 0 ≦ y <0.6, and z takes a value of 0 ≦ z ≦ 2.0. A method for producing a lithium manganese composite oxide powder, comprising subjecting a pulverized lithium manganese composite oxide represented by the formula) to a heat treatment at 300 to 800 ° C. 5. A pulverized lithium manganese composite oxide represented by the general formula (1) is obtained by mixing a manganese compound and a lithium compound,
The method for producing a lithium manganese composite oxide powder according to claim 4, which is a crushed product of a lithium manganese composite oxide obtained by firing at a temperature of not less than ° C. 6. A pulverized lithium manganese composite oxide represented by the general formula (1), comprising mixing a manganese compound, a lithium compound, an aluminum compound, a zirconium compound or a zinc compound,
The method for producing a lithium manganese composite oxide powder according to claim 4, which is a pulverized lithium manganese composite oxide obtained by firing at 900 ° C or higher. 7. A pulverized lithium manganese composite oxide represented by the general formula (1) is obtained by heat-treating a manganese compound at 900 ° C. or higher to obtain a manganese oxide. The method for producing a lithium manganese composite oxide powder according to claim 4, which is a pulverized lithium manganese composite oxide obtained by mixing and firing. 8. A pulverized lithium-manganese composite oxide represented by the general formula (1) is obtained by heat-treating a manganese compound at 900 ° C. or higher to obtain a manganese oxide. The method for producing a lithium manganese composite oxide powder according to claim 4, which is a pulverized lithium manganese composite oxide obtained by mixing an aluminum compound, a zirconium compound or a zinc compound and firing the mixture. 9. A mixture obtained by heat-treating a manganese compound and an aluminum compound, a zirconium compound or a zinc compound at 900 ° C. or higher as a pulverized product of the lithium-manganese composite oxide represented by the general formula (1). 5. A method for producing a lithium manganese composite oxide powder according to claim 4, which is a pulverized product of a lithium manganese composite oxide obtained by mixing and firing a lithium compound. 10. A pulverized lithium-manganese composite oxide represented by the general formula (1) is obtained by heat-treating a manganese compound at 900 ° C. or more, and
After heat treatment at less than 0 ° C., the obtained manganese oxide,
The method for producing a lithium manganese composite oxide powder according to claim 4, which is a pulverized lithium manganese composite oxide obtained by mixing and firing a lithium compound. 11. A pulverized lithium-manganese composite oxide represented by the general formula (1) is obtained by heat-treating a manganese compound at 900 ° C. or more, and
After heat treatment at less than 0 ° C., the obtained manganese oxide,
5. The lithium manganese composite oxide powder according to claim 4, which is a pulverized lithium manganese composite oxide obtained by mixing a lithium compound, an aluminum compound, a zirconium compound or a zinc compound and firing the mixture. Method. 12. A pulverized lithium-manganese composite oxide represented by the general formula (1) is obtained by heat-treating a manganese compound and an aluminum compound, a zirconium compound or a zinc compound at 900 ° C. or higher, and further lower than 900 ° C. After the heat treatment in the obtained mixture,
The method for producing a lithium manganese composite oxide powder according to claim 4, which is a pulverized lithium manganese composite oxide obtained by mixing and firing a lithium compound. 13. A pulverized lithium manganese composite oxide represented by the general formula (1) is obtained by heat-treating a manganese compound and an aluminum compound at 900 ° C. or higher, and further heat-treating at a temperature lower than 900 ° C. 5. A pulverized lithium manganese composite oxide obtained by mixing a mixture, a lithium compound, a zirconium compound or a zinc compound, and firing the mixture.
The method for producing a lithium manganese composite oxide powder according to the above. 14. The pulverized lithium manganese composite oxide has an average particle size of 0.1 to 50 μm and a BET
Method for producing a lithium manganese composite oxide powder of any one of claims 4-13, wherein the specific surface area of 0.1~2.0m ² / g. 15. A positive electrode active material for a lithium secondary battery, comprising the lithium manganese composite oxide powder according to claim 1. Description: 16. A lithium secondary battery comprising the lithium secondary battery positive electrode active material according to claim 15.