JP2001163622A - Lithium manganese oxide, method for producing the same, and secondary battery using the same - Google Patents

Abstract

An object of the present invention is to provide, as a cathode material for a Li secondary battery, a high-performance spinel-structured lithium manganese-based oxide having excellent long-term cycle stability, a method for producing the same, and a method for producing the same. It is intended to provide a high-performance lithium secondary battery used. SOLUTION: {Li} [Li _x Mn _2-x ] O ₄ (where,
｛｝ Indicates the 8a site, [] indicates the 16d site, and 0.0
8 <x ≦ 0.15) and the Na content is 0.001
a spinel-structured lithium manganese-based oxide characterized by having an average primary particle diameter of 0.5 to 2.0 μm by SEM observation, and a spinel structure having a cubic spinel structure. A spinel-structured lithium manganese-based oxide, wherein the cubic crystal has a lattice constant (a) according to the following equation: a ≦ 8.2476−0.25 × x

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium manganese oxide having a spinel structure, a method for producing the same, and a lithium secondary battery using the same.

[0002] Manganese oxide has long been used as a battery active material, and a lithium manganese composite oxide, which is a composite material of manganese and lithium, has recently attracted attention as a positive electrode active material of a lithium secondary battery. Is the material that is being used.

[0003]

2. Description of the Related Art Due to high energy density and high output, lithium secondary batteries have attracted attention as new high-performance batteries in recent years as electronic devices have become smaller and lighter.

A positive electrode material for a lithium secondary battery is required to have a high voltage operating range, a high discharge capacity, and a high cycle stability, and Li and various metals such as Co, Ni, Mn, Complex oxides such as V are being studied. LiMn ₂ O ₄ having a spinel structure, which is a kind of a composite oxide of Li and Mn, is considered to be promising as a positive electrode active material, but it is difficult to cycle reversibly over a long period of time. There is a problem that the electrochemical capacity of the battery decreases. In particular, it was found that when operated under a high temperature condition of 50 ° C. to 60 ° C., the decrease in electrochemical capacity was remarkable.

[0005] Further, since a composite oxide of Li and Mn is used, when a lithium manganese-based oxide having a spinel structure is produced, a variation in composition occurs, and the lithium manganese-based oxide having a spinel structure is used as a positive electrode of a lithium secondary battery. The effect on battery performance when used in a battery is a problem.

Various production methods for improving uniformity such as liquid phase synthesis have been proposed, but practical use is difficult such as expensive raw materials, vigorous reaction, and expensive equipment.

[0007]

The object of the present invention is to
High performance spinel structure lithium manganese oxide with excellent long-term cycle stability as a cathode material for secondary batteries and a spinel structure with high uniformity by solid-phase reaction using inexpensive raw materials An object of the present invention is to provide a method for producing lithium manganese and a high-performance lithium secondary battery using the same.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the general formula {Li} [Li _x Mn _2-x ] O ₄ (where ｛｝ represents the 8a site and [] represents the 16d site) Show,
0.08 <x ≦ 0.15), and the Na content is 0.1.
1 wt% or less, the average primary particle diameter of 0.
It has been found that a lithium manganese-based oxide having a spinel structure characterized by a thickness of 5 to 2.0 μm can achieve the above object.

Further, as a method for producing a spinel-structured lithium manganese-based oxide according to the present invention, a method for producing a spinel-structured lithium-manganese-based oxide in which a lithium raw material and a manganese raw material are mixed and fired is described. It has been found that a method for producing a lithium manganese-based oxide having a spinel structure characterized by using a raw material having a particle diameter ratio of 1/5 to 1/30 can achieve the above object.

As another production method, there is provided a method for producing a lithium manganese oxide having a spinel structure in which a lithium material and a manganese material are mixed and then calcined. It has been found that a method for producing a product can achieve the above object.

Further, as another production method, there is provided a method for producing a spinel-structured lithium manganese oxide in which a lithium raw material and a manganese raw material are mixed and then fired. It has been found that the above object can be achieved by performing a main heat treatment at 950 ° C. and a post heat treatment at 600 ° C. to 900 ° C.

Further, a high performance lithium secondary battery using the lithium manganese oxide having a spinel structure of the present invention as a positive electrode active material has been found, and the present invention has been completed.

[0013]

Hereinafter, the present invention will be described in detail.

The spinel-structured lithium manganese-based oxide of the present invention has a general formula {Li} [Li _x Mn _2-x ] O ₄ (where ｛｝ represents an 8a site, and [] represents a 16d site;
0.08 <x ≦ 0.15), wherein Li exists at the 8a site and 16d site, and Mn exists at the 16d site.

Here, the value of x in the equation is 0.08 <x ≦
0.15.

When the value x is 0.08 or less, the cycle stability of the formed lithium manganese oxide having a spinel structure is poor. When the value is more than 0.15, the available electric capacity is small, and neither is advantageous.

Preferably, the value x is 0.09 ≦ x ≦ 0.12.

The spinel-structured lithium manganese oxide of the present invention has an X-ray diffraction pattern of JCPDS35-78.
This is a cubic spinel exhibiting a pattern close to 2, and has a lattice constant (a) according to the following equation.

A ≦ 8.2476−0.25 × x If the lattice constant is larger than the above value, the cycle stability becomes poor, which is not preferable.

The spinel-structured lithium manganese oxide according to the present invention has a Na content of 0.001 wt% or more and 0.1 wt% or more.
wt% or less.

When the Na content is more than 0.1% by weight,
When used as a positive electrode active material, it causes contamination of the negative electrode and the like, which is not preferable.

The Na content is preferably 0.05% by weight or less.

The spinel-structured lithium manganese oxide of the present invention has an average primary particle diameter of 0.5 as measured by SEM observation.
２．０2.0 μm.

In the present invention, the average primary particle diameter by SEM observation is an average value obtained by analyzing an image of an SEM observation image of a powder and obtaining an equivalent circle diameter.

If the average primary particle size is smaller than 0.5 μm, the stability in the electrolyte tends to deteriorate, and if the average primary particle size is larger than 2.0 μm, the electric capacity tends to decrease, and none of them has high performance as a battery active material. .

The average primary particle diameter is preferably 0.8 to 1.2 μm.

The spinel-structured lithium manganese oxide of the present invention preferably has a BET specific surface area of 0.1 to 2.0 m ² / g.

If the BET specific surface area is less than 0.1 m ² / g, the usable electric capacity is undesirably reduced. On the other hand, when it is larger than 2.0 m ² / g, the active material, the conductive material, and the like are slurried, and a large amount of solvent is required when producing an electrode sheet, which tends to increase the viscosity of the produced slurry,
It is not preferable because it causes trouble during the production of the battery positive electrode.

The BET specific surface area is 0.3 to 1.0 m ² /
g is more preferable.

In the method for producing a lithium manganese oxide having a spinel structure according to the present invention, the manganese raw material is as follows:
It is preferable to use a manganese raw material having an average particle diameter of 30 μm or less.

The average particle diameter is a 50% diameter in terms of volume (d ₅₀ ) measured by the Microtrac method.

Of the manganese raw materials, electrolytic manganese dioxide is preferred because its primary particles have high uniformity.
Those having a size of less than μm are preferred because of their good reactivity.

Further, the use of manganese oxide, which is a substantially single crystal phase obtained by heat-treating electrolytic manganese dioxide having an average particle diameter of 30 μm or less as a manganese raw material, also makes the crystal phase uniform. This is preferable because the reaction with the lithium raw material becomes uniform. It is preferable to use electrolytic manganese dioxide having a Na content of 0.1 wt% or less as a Mn raw material.

Electrolytic manganese dioxide is preferable because the spinel-structured lithium manganese-based oxide produced is denser and the average primary particle diameter is larger than other manganese oxides and compounds. The battery performance of the object was easily lowered.

The present inventors have conducted intensive studies and as a result, have found that electrolytic manganese dioxide having a Na content of 0.1 wt% or less is M
By using n as a raw material, it was possible to obtain a spinel-structured lithium manganese-based oxide having a large average primary particle diameter and a small decrease in battery performance.

[0036] The Na content is preferably at most 0.05 wt%, particularly preferably at most 0.02 wt%.

In general, electrolytic manganese dioxide is electrolyzed in a sulfuric acid acid bath, and is often subjected to a neutralization treatment with an aqueous solution of caustic soda after electrolysis, which is a cause of an increase in the Na content.

The electrolytic manganese dioxide having a Na content of 0.1 wt% or less is not neutralized after the electrolysis, but is washed with water or hot water. To obtain a neutralization treatment.

In particular, in order to remove the sulfuric acid content and the sulfuric acid content contained in the electrolytic bath, it is preferable to carry out the electrolytic manganese dioxide produced in combination with washing, neutralization and the like.

Further, the present inventors use manganese oxide, which is a substantially single crystal phase obtained by heat-treating electrolytic manganese dioxide, as a Mn raw material, so that the reaction with the Li raw material is uniform. I've found it to go.

That is, it is preferable to use a manganese oxide which is a substantially single crystal phase obtained by heat treatment of electrolytic manganese dioxide having a Na content of 0.1 wt% or less as a Mn raw material.

Instead of using electrolytic manganese dioxide having a Na content of 0.1 wt% or less, a manganese oxide obtained by heat-treating electrolytic manganese dioxide is washed to reduce the Na content to 0.1 wt% or less. It is preferable to use a manganese oxide which is substantially a single crystal phase as a Mn raw material.

The heat treatment of electrolytic manganese dioxide is carried out in air.
It is preferably performed at 600 to 1100 ° C.

It is preferable that the manganese oxide obtained by heat-treating the electrolytic manganese dioxide is substantially a single phase of Mn ₂ O ₃ or a single phase of Mn ₃ O ₄ .
In particular, Mn ₂ O ₃ is preferable because the valence of Mn is close to the valence of Mn in LiMn ₂ O ₄ .

The manganese compound has a BET specific surface area of 2
It is preferably 0 m ² / g or less from the viewpoint of reactivity and handleability.

Examples of the Li compound include carbonates, nitrates, chlorides, hydroxides and oxides. In particular, lithium carbonate having a BET specific surface area of 1 m ² / g or more has good reactivity. Low hygroscopicity is preferable.

When lithium carbonate is used, the average particle size is preferably 5 μm or less. In particular, it is preferably 2 μm or less.

If the particle size exceeds 5 μm, the reactivity of lithium carbonate is poor, which is not preferable.

If the mixing of the raw materials can be made uniform,
Any method of a usual method can be adopted, and it is also preferable to perform heat treatment while mixing like a rotor kiln or the like. In the present invention, after mixing the manganese oxide and the lithium compound prepared as described above, at least once, a temporary heat treatment of maintaining the temperature below 900 ° C.,
After the remixing, it is preferable to perform the main heat treatment at 750 ° C. to 950 ° C. because uniformity can be improved.

Further, in order to reduce oxygen deficiency and structural defects in the product, after the main heat treatment at 750 to 950 ° C., a post heat treatment at 600 to 900 ° C. in an oxygen-containing atmosphere is performed. Is preferred.

The post-heating treatment is performed after the main heating treatment at 750 ° C. to 950 ° C. and continuously in an oxygen-containing atmosphere.
It is more preferable to perform a heat treatment after holding at 600 ° C. to 900 ° C., and it is particularly preferable to perform the heat treatment a plurality of times.

It is preferable that all heat treatments be performed in an oxygen-containing atmosphere.

When the heat treatment conditions are out of the above range, the average primary particle diameter of the product is out of the desired range, and oxygen deficiency,
It is not preferable that a structural defect is generated.

It is preferable that the produced lithium manganese oxide having a spinel structure is appropriately pulverized and classified. The spinel-structured lithium manganese-based oxide of the present invention can be manufactured by the above-described manufacturing method.

As a result of intensive studies, the present inventors have found that in a method for producing a lithium manganese-based oxide having a spinel structure in which a lithium raw material and a manganese raw material are mixed and fired, the ratio of the average particle diameter of the lithium raw material to the manganese raw material is 1/1. 5/3
It has been found that the above object can also be achieved by a method for producing a lithium manganese-based oxide having a spinel structure characterized by using a raw material of 0.

In the production method of the present invention, if it is larger than 5 μm, the reactivity of lithium carbonate is not good, which is not preferable.

The lithium raw material is preferably lithium carbonate having an average particle diameter of 2 μm or less.

As the manganese raw material of the present invention, it is preferable to use a manganese raw material having an average particle diameter of 30 μm or less.

Among the manganese raw materials, electrolytic manganese dioxide is preferred because of high uniformity of the primary particles.
Those having a size of less than μm are preferred because of their good reactivity.

Further, the use of manganese oxide, which is a substantially single crystal phase obtained by heat-treating electrolytic manganese dioxide having an average particle diameter of 30 μm or less as a manganese raw material, makes the crystal phase uniform. This is preferable because the reaction with the lithium raw material becomes uniform.

Further, in the method for producing a lithium manganese-based oxide having a spinel structure according to the present invention, it is preferable that the mixing of the lithium raw material and the manganese raw material is performed by cooling, or after the mixing, while cooling the granulated material.

When the mixing is performed without cooling as in the present invention, the raw materials are easily denatured by the heat generated during the mixing, and it is difficult to uniformly mix the lithium raw material and the manganese raw material.

The cooling can be performed by any ordinary method,
The temperature at the time of mixing is preferably 30 ° C. or lower.

In the present invention, it is preferable to carry out the mixing with a stirring mixer in order to improve the uniformity. However, as long as the raw materials can be uniformly mixed, any of the ordinary methods can be employed, such as a rotor kiln. It is also preferable to perform the heat treatment while mixing.

In the method for producing a spinel-structured lithium manganese oxide granule of the present invention, it is preferable to mix a lithium raw material and a manganese raw material and then produce the granulated body while cooling.

In particular, when the mixed powder is molded or granulated after mixing, it is easy to handle, unlike the powder.

By producing granules while cooling as in the present invention, a uniform mixed powder can be granulated, and when heat treatment is further performed, the reaction proceeds uniformly, which is preferable.

Further, a Li secondary battery using the lithium manganese oxide having a spinel structure of the present invention as a positive electrode active material was manufactured.

As the negative electrode active material used in the Li secondary battery of the present invention, a material capable of inserting and extracting lithium metal and lithium or lithium ions can be used. For example, metallic lithium, lithium / aluminum alloy, lithium / tin alloy, lithium / lead alloy, and a carbon material capable of electrochemically inserting / desorbing lithium ions are exemplified. A carbon material that can be desorbed is particularly suitable in terms of safety and battery characteristics.

The electrolyte used in the Li secondary battery of the present invention is not particularly limited. For example, an electrolyte obtained by dissolving a lithium salt in an organic solvent such as carbonates, sulfolanes, lactones, and ethers may be used. Alternatively, a lithium ion conductive solid electrolyte can be used.

The separator used in the Li secondary battery of the present invention is not particularly limited. For example, a lithium manganese-based oxide having a spinel structure of the present invention in which a microporous film made of polyethylene or polypropylene can be used. Was used as a positive electrode material to construct the battery shown in FIG.

In the figure, there are shown: a lid, an insulator made of Teflon (registered trademark), a negative electrode current collecting mesh, a negative electrode, a separator, a positive electrode, a positive electrode current collecting mesh, and a container.

In the present invention, a stable and high-performance Li secondary battery could be obtained using the above-described positive electrode active material, negative electrode active material and lithium salt-containing nonaqueous electrolyte.

[0074]

EXAMPLES Each measurement in Examples and Comparative Examples of the present invention was carried out under the following conditions.

The XRD pattern was measured under the following conditions.

Measuring machine: MXP-3, McScience Inc. Irradiation X-ray: CuKα ray Measurement mode: Step scan Scan condition: 0.04 degrees per second Measurement time: 3 seconds Measurement range: 5 to 80 degrees as 2θ ・ Composition analysis Performed by ICP spectroscopy.

"Production of lithium manganese-based oxide having spinel structure" As an example and a comparative example, it was produced by the following method.

Example 1 An electrolytic manganese dioxide having an average particle size of 15 μm and a Na content of 0.01 wt% was subjected to a heat treatment at 800 ° C. for 12 hours in the air, and Mn having a pattern equivalent to that of a JCPDS card: 41-1442. ₂ O ₃ was synthesized. This Mn ₂ O ₃ and lithium carbonate having an average particle size of 2 μm and a BET specific surface area of 3 m ² / g were weighed and mixed so that the Li / Mn ratio became 0.58.
Mixing is performed by a stirring and mixing granulator (FM-VG- manufactured by Powrex).
50), while passing water through the jacket and cooling to 25 ° C.

The mixed powder thus obtained was placed in the air at 600
Temporary heat treatment at 6 ° C. for 6 hours, and after cooling to room temperature, re-mixing was performed, and the main heat treatment was performed at 800 ° C. in the air for 24 hours.
Further, a post-heating treatment was performed at 700 ° C. for 24 hours in the atmosphere.

The product was analyzed by powder X-ray diffraction using JCPDS
35-782 (LiMn204; lattice constant 8.2476)
Cubic spinel (lattice constant 8.220) showing a diffraction pattern equivalent to 2 angstrom and slightly different lattice constants.
Angstrom). According to ICP spectroscopy, the chemical composition was {Li} [Li _0.1 Mn _1.9 ] O ₄ and the Na content was 0.01 wt%.

As a result of SEM observation, the product was found to be 0.1%
An aggregate in which crystal particles (primary particles) of about 7 μm were uniformly formed was formed, and the BET specific surface area was 0.7 m ² / g.

The following battery was prepared using the lithium manganese oxide thus obtained as a positive electrode, and a positive electrode characteristic test was performed. Mixture of positive electrode sample and conductive polytetrafluoroethylene and acetylene black (trade name: TA
B-2) was mixed at a weight ratio of 2: 1 to obtain SUS31.
After being formed into a pellet shape on a 6-mesh with a pressure of 1 ton / cm ² , it was dried under reduced pressure at 200 ° C. for 24 hours. This was used as a positive electrode of a battery, a metal lithium foil (0.2 mm in thickness) was used as a negative electrode, and lithium hexafluorophosphate (LiPF ₆ ) was used as an electrolyte in a mixed solvent of propylene carbonate and diethyl carbonate at 1 mol / L. The separator was impregnated with a solution dissolved at a concentration of dm ³ to form a battery.

Using the battery thus manufactured, charging and discharging at a constant current of 1.0 mA / cm ² were repeated at a test temperature of 50 ° C. and a battery voltage of 4.5 V to 3.5 V. As a result, the capacity retention ratio (% of the discharge capacity on the 50th cycle day with respect to the 10th cycle) was 95%.

Example 2 As heat treatment conditions at the time of synthesis, a temporary heat treatment was performed at 600 ° C. in the atmosphere for 6 hours, and after mixing at room temperature, mixing was performed again. Further, the synthesis and battery evaluation were performed in the same manner as in Example 1 except that post-heating treatment was performed at 800 ° C. for 24 hours in the atmosphere.

The product was identified as cubic spinel (lattice constant: 8.222 Å) by X-ray powder diffraction, and the chemical composition was determined by ICP spectroscopy to be {Li} [L
i _0.1 Mn _1.9 ] O ₄ and the Na content is 0.01 wt%
Met. As a result of SEM observation, the product was found to be 0.8
An aggregate in which crystal particles (primary particles) of about μm were uniformly arranged was formed, and the BET specific surface area was 0.4 m ² / g.

As a result of the battery test, the capacity retention rate (10
(% Of the discharge capacity on the 50th cycle day with respect to the cycle) was 92%.

Example 3 Synthesis and battery evaluation were carried out in the same manner as in Example 1 except that granulation was performed by adding a 2 wt% aqueous solution of polyvinyl alcohol and stirring for 15 minutes as mixing conditions during synthesis. . At the end of the granulation, most of the granules had a size of 1 to 5 mmφ, and the composition deviation due to random sampling of the granules was within 1%.

The product obtained in this way is described in Example 1.
It showed the same physical properties and battery characteristics as.

Comparative Example 1 Synthesis was performed under the same conditions as in Example 1 except that the Na content of the electrolytic manganese dioxide used as the Mn raw material was 0.2 wt%.

As a result, the crystal phase and the composition were the same, but the lattice constant was slightly smaller at 8.218 angstroms, the average primary particle diameter was 1.0 μm, and the BET specific surface area was 0.9.
The powder properties were different from m ² / g. As a result of the battery test, the capacity retention was 85%, which was significantly inferior to Example 1.

Comparative Example 2 Synthesis was performed under the same conditions as in Example 2 except that the Na content of the electrolytic manganese dioxide used as the Mn raw material was 0.2 wt%.

As a result, the crystal phase and the composition were the same, but the lattice constant was slightly smaller at 8.220 angstroms, the average primary particle diameter was 1.2 μm, and the BET specific surface area was 1.2.
The powder properties were different from m ² / g. As a result of the battery test, the capacity retention ratio was 80%, which was significantly inferior to Example 2.

Comparative Example 3 In the synthesis process, synthesis was performed under the same conditions as in Examples 1 and 2, except that post-heating was not performed after the main heating.

As a result, the crystal phases were the same, but the lattice constants were larger than those of Examples 1 and 2, respectively. As a result of chemical analysis, the average oxidation number of Mn was smaller than the theoretically calculated value, and it was considered that there was an oxygen defect. The battery performance of these products was significantly inferior to Examples 1 and 2.

Comparative Example 4 Synthesis was carried out under the same conditions as in Example 1 except that lithium carbonate having an average particle size of 10 μm was used as a Li raw material.

As a result, in Example 1 in which lithium carbonate having an average particle size of 2 μm was used, a single phase of cubic spinel was formed by provisional heating at 600 ° C. for 6 hours in the air, whereas the average particle size was 10 μm. 700 when lithium carbonate is used
A single phase could not be obtained even at a heat treatment of ° C. Also, 80
Although the cubic spinel single phase was formed by the main heat treatment at 0 ° C., the size of the primary crystal grains was not uniform by SEM observation, and it was considered that the reaction occurred unevenly. The battery performance of such a product was remarkably inferior to that of Example 1.

Comparative Example 5 Synthesis was carried out under the same conditions as in Examples 1 and 3, except that water was not passed through the jacket and cooling was not performed when mixing the Li raw material and the Mn raw material.

As a result, the temperature at the end of the mixing increased to 45 ° C., and it was confirmed that white powder of lithium carbonate had adhered to the inner wall of the mixer. As a result of performing composition analysis by random sampling, the deviation from the charged composition reached 3%. In addition, when agitation granulation was performed by adding a 2 wt% polyvinyl alcohol aqueous solution, a strong adhered substance was formed on the inner wall of the mixer, and uniform granules could not be obtained.

[0099]

According to the present invention, a stable and high performance Li secondary battery can be obtained using the above-described positive electrode active material, negative electrode active material and lithium salt-containing non-aqueous electrolyte.

[Brief description of the drawings]

FIG. 1 shows a configuration diagram of a battery using a spinel-structured lithium manganese-based oxide of the present invention as a positive electrode sealing material.

[Explanation of symbols]: Lid: Teflon insulator: Negative electrode current collector mesh: Negative electrode: Separator: Positive electrode: Positive electrode current collector mesh: Container

 ──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 11-281625 (32) Priority date October 1, 1999 (Oct. 1st, 1999) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 11-281626 (32) Priority date October 1, 1999 (Oct. 10.1, 1999) (33) Priority claim country Japan (JP)

Claims (24)

[Claims] A cubic spinel structure having a composition of {Li} [Li _x Mn _2-x ] O ₄ (where ｛｝ represents an 8a site, [] represents a 16d site, and 0.08 <X ≦ 0.
15) A lithium manganese oxide, wherein the cubic crystal has a lattice constant (a, unit: angstrom) represented by the following formula: a ≦ 8.2476−0.25 × x 2. The spinel-structured lithium manganese oxide according to claim 1, wherein x is 0.09 ≦ x ≦ 0.1.
2. A lithium manganese oxide, which is 2. 3. The spinel-structured lithium manganese oxide according to claim 1, wherein N is contained as an impurity.
A spinel-structured lithium manganese oxide having an a content of 0.001 wt% or more and 0.1 wt% or less. 4. The lithium manganese oxide having a spinel structure according to claim 3, wherein the content of Na contained as an impurity is 0.001% by weight or more and 0.05% by weight or less. Oxides. 5. The spinel-structured lithium manganese oxide according to claim 3, wherein the content of Na contained as an impurity is not less than 0.001% by weight and not more than 0.02% by weight. Oxides. 6. The spinel-structured lithium manganese oxide according to claim 1, having a BET specific surface area of 0.1 m
Spinel type lithium manganese oxide, characterized in that at most ² / g or more 2.0 m ² / g. 7. The lithium manganese oxide having a spinel structure according to claim 6, wherein the BET specific surface area is 0.3 m ² /
g of lithium manganese oxide having a spinel structure of at least 1.0 m ² / g. 8. The lithium manganese oxide having a spinel structure according to claim 1, wherein the average primary particle diameter as observed by SEM is 0.5 μm or more and 2.0 μm or less. . 9. The spinel-structured lithium manganese oxide according to claim 8, wherein the average primary particle diameter as observed by SEM is 0.8 μm or more and 1.2 μm or less. 10. A method for producing a lithium manganese oxide having a spinel structure, comprising mixing a lithium raw material and a manganese raw material and calcining the mixture, and after mixing the manganese oxide and the lithium compound, temporarily heating the mixture at least once to a temperature of less than 900 ° C. After processing and remixing, at least once 750
The method for producing a spinel-structured lithium manganese oxide according to any one of claims 1 to 9, wherein the main heat treatment is performed at a temperature of from 0 ° C to 950 ° C. 11. The lithium manganese spinel structure according to claim 10, wherein after the main heat treatment at 750 ° C. to 950 ° C., a post heat treatment at 600 ° C. to 900 ° C. in an oxygen-containing atmosphere is performed. A method for producing an oxide. 12. After the main heat treatment at 750 ° C. to 950 ° C., continuously in an oxygen-containing atmosphere at 600 ° C. to 900 ° C.
2. A heat treatment is carried out after holding at a temperature.
0. The method for producing a lithium manganese oxide having a spinel structure according to item 0. 13. The method according to claim 10, wherein after the main heat treatment at 750 to 950 ° C., a plurality of post heat treatments at 600 to 900 ° C. in an oxygen-containing atmosphere are performed.
A method for producing the spinel-structured lithium manganese-based oxide according to the above. 14. The method for producing a spinel-structured lithium manganese-based oxide according to claim 10, wherein all the heat treatments are performed in an oxygen-containing atmosphere. 15. A substantially Mn ₂ O ₃ single crystal phase obtained by heat-treating electrolytic manganese dioxide having a Na content of 0.1% by weight or less at 600 to 1100 ° C. in the air, or
Method for producing a spinel-type lithium-manganese oxide as claimed in claim 10, wherein the use of Mn ₃ O _4, manganese oxides are single-phase one crystal. 16. An electrolytic manganese dioxide in the atmosphere of 600-1.
The manganese oxide which is substantially a Mn ₂ O ₃ single crystal phase or a Mn ₃ O ₄ single crystal phase obtained by heat treatment at 100 ° C. is washed to reduce the Na content to 0.1 wt% or less. The method for producing a spinel-structured lithium manganese oxide according to claim 10, wherein the method is used. 17. The method for producing a lithium manganese oxide having a spinel structure according to claim 10, wherein the ratio of the average particle diameter of the lithium material to the manganese material is 1/5 or more and 1/30 or less, more preferably 1/10 or more. A method for producing a lithium manganese oxide having a spinel structure, which is not more than 1/20. 18. The method for producing a lithium manganese oxide having a spinel structure according to claim 17, wherein lithium carbonate having an average particle diameter of 5 μm or less is used as a lithium raw material. 19. The method for producing a lithium manganese oxide having a spinel structure according to claim 18, wherein lithium carbonate having an average particle diameter of 2 μm or less is used as a lithium raw material. 20. The method for producing a lithium manganese oxide having a spinel structure according to claim 17, wherein a manganese raw material having an average particle diameter of 30 μm or less is used. 21. The method for producing a lithium manganese oxide having a spinel structure according to claim 17, wherein the lithium raw material and the manganese raw material are stirred and mixed at a temperature of 30 ° C. or less. Method. 22. The method for producing a lithium manganese oxide having a spinel structure according to claim 21, wherein a lithium material and a manganese material are stirred and mixed at a temperature of 30 ° C. or less to produce a granulated body. Method for producing granulated lithium manganese oxide. 23. A Li secondary battery using the spinel-structured lithium manganese oxide according to claim 1 as a positive electrode. 24. Electrolyte doped with lithium ions.
24. The Li secondary battery according to claim 23, wherein the undoped carbon-based material is used as a negative electrode.