JPH10228929A - Organic electrolyte solution secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electrolyte solution secondary battery having excellent storing and cycling characteristics by controlling elusion of manganese at an organic electrolyte solution secondary battery that uses an oxide including manganese as an active material. SOLUTION: At an organic electrolyte solution secondary battery using an oxide including maganese such as LiMn2 O4 , LiMnO2 as a positive electrode active material or a negative electrode active material and using a solution in which one or more kinds selected among LiBF4 , LiN (R1 )(R2 )(R1 =Cx F2x+1 SO2 , R2 =Cy F2y+1 SO2 , X+Y>=2) is dissolved as an electrolyte solution, 0.08cc to 0.8cc of the electrolyte solution is used per 1m2 surface area. Including 1 to 15volume% of ether in an electrolyte solvent of the electrolyte solution is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electrolyte secondary battery, and more particularly to an organic electrolyte secondary battery using an oxide containing manganese as an active material. The present invention relates to an organic electrolyte secondary battery having improved characteristics.

[0002]

2. Description of the Related Art In recent years, lithium ion batteries using lithium cobalt oxide as an active material have been used as a power source for various electric appliances. However, the lithium cobalt oxide has a problem that the price is high because cobalt is an expensive metal.

[0003] Therefore, lithium ion batteries using less expensive lithium manganese oxide have been produced. However, lithium manganese oxide is used as an active material, and LiP, which is currently most frequently used as an electrolyte, is used.
With those dissolved F ₆ in an organic solvent, elution of manganese from lithium manganese oxide becomes significant, there is a problem that the storage characteristics and cycle characteristics are deteriorated.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and solves the problems of the prior art by using an organic electrolyte secondary battery using an oxide containing manganese such as lithium manganese oxide as an active material. It is an object of the present invention to provide an organic electrolyte secondary battery having improved storage solution, suppressed elution of manganese, and excellent storage characteristics and cycle characteristics.

[0005]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that LiMn
Manganese-containing oxides such as ₂ O ₄ and LiMnO ₂ are used as a positive electrode active material or a negative electrode active material, and LiBF ₄ and LiN (R ₁ ) (R ₂ ) (R ₁ = C _x F _{2x + 1} SO ₂ ,
In _{R 2 = C y F 2y +} 1 SO 2, x + y ≧ 2) 1 type or an organic electrolyte secondary battery using the two or more that is dissolved in an organic solvent as an electrolyte selected from the above 0.08 cc of the above electrolytic solution per 1 m ² of the surface area of the active material
When 0.8 cc is used, the elution of manganese is suppressed,
The inventors have found that an organic electrolyte secondary battery having excellent storage characteristics and cycle characteristics can be obtained, and have completed the present invention.

Further, the present inventors have found that when the electrolyte solution of the above-mentioned battery contains 1 to 15% by volume of ether, the organic electrolysis solution having further improved cycle characteristics and excellent load characteristics. It has been found that a liquid secondary battery can be obtained.

That is, as described above, LiMn
When a battery is manufactured using an oxide containing manganese such as ₂ O ₄ or LiMnO ₂ as an active material, LiBF ₄ and LiN (R ₁ ) (R ₂ ) (R ₁ = C _x F _{2x + 1} SO ₂ ,
R ₂ = C _y F _{2y + 1} SO ₂ , x + y ≧ 2), when one or two or more kinds thereof dissolved in an organic solvent are used as an electrolytic solution, the most frequently used LiPF
Compared to a case where ₆ is dissolved in an organic solvent, the elution of manganese is suppressed as compared with the case where the electrolytic solution is used, and as a result, storage characteristics and cycle characteristics are improved.

This is because the above-mentioned LiBF ₄ and LiN (R
_{1) (R 2) (R} 1 = C x F 2x + 1 SO 2, R 2 = C y F
BF ₄ ^- or N (R ₁ ) when one or two selected from _{2y + 1} SO ₂ and x + y ≧ 2) are dissolved in an organic solvent.
(R ₂₎ ^- is reacted with the oxide containing manganese such as P
F ₆ ^- lower than that considered to be due to the difficult eluted manganese.

Further, when an electrolytic solution having a concentration of more than 0.8 cc per 1 m ² of the surface area of the active material composed of the oxide containing manganese is used, the elution of manganese tends to increase.
It is necessary that the electrolytic solution be 0.8 cc or less per 1 m ² of the surface area of the active material. Conversely, if an electrolytic solution of less than 0.08 cc per 1 m ² of the surface area of the active material made of an oxide containing manganese is used, Since the load characteristics and the low-temperature characteristics tend to decrease, the electrolyte needs to be 0.08 cc or more per 1 m ² of the surface area of the active material.

[0010] As described above, when an electrolytic solution having an amount of more than 0.8 cc per 1 m ² of the surface area of an active material composed of an oxide containing manganese is used, the cause of the large elution of manganese is that Is limited in manganese solubility, and the relative elution amount of manganese may increase.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, L as an active material
IMN ₂ O _4, as the oxide containing manganese such as LiMnO _2, LiMn ₂ of the exemplary O ₄ or LiMnO ₂
Besides, for example, Mn ₂ O ₃ , MnO ₂ , Mn ₃ O
₄ , Li ₂ Mn ₄ O ₉ , Li ₄ Mn ₅ O ₁₂ , LiMn ₃
O ₄ and Li ₂ Mn ₂ O ₅ are exemplified.

In the present invention, LiBF _{4 serving as} an electrolyte is used.
And LiN (R ₁ ) (R ₂ ) (R ₁ = C _x F _{2x + 1} SO
_2, the concentration of _{R 2 = C y F 2y +} 1 SO 2, x + y ≧ 2) 1 or more kinds of electrolyte selected from among, 0.3 mol / l to 1.7 mol / L, preferably 0.7 mol / l to 1.
Preferably it is 5 mol / l.

In the present invention, in preparing the electrolytic solution, LiBF ₄ and LiN (R ₁ ) (R ₂ )
_{(R 1 = C x F 2x} + 1 SO 2, R 2 = C y F 2y + 1 SO 2,
x + y ≧ 2), an organic solvent for dissolving one or more selected from two or more, ie, an electrolyte solvent,
For example, cyclic esters such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, ν-butyrolactone (ν-BL) and σ-valerolactone, 1,2-bismethoxycarbonyloxyethane, and 1,2-bis Ethoxycarbonyloxyethane, 1,2-bismethoxycarbonyloxypropane,
Examples thereof include alkylene biscarbonate compounds such as 1,2-bisethoxycarbonyloxypropane, and chain carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (MEC). They can be used, or two or more of them can be used in combination.

As the ether, for example, 1,
2-dimethoxyethane (DME), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2Me-
THF), 1,3-dioxolan, 4-methyl-1,3
-Dioxolane, etc., and these ethers can be used alone or in combination of two or more. When these ethers are contained in the electrolyte solution solvent in the range of 1 to 15% by volume, the cycle characteristics are further improved, and the load characteristics are further improved.
This is considered to be due to the fact that when the ether is contained in the above range, the conductivity of the electrolytic solution increases and the polarization decreases. When the ether content is less than 1% by volume in the electrolyte solvent, the effect of further improving the cycle characteristics and the load characteristics is not sufficiently exhibited, and the ether content is 15% in the electrolyte solvent. If it is more than volume%,
Although the cycle characteristics may be deteriorated, this ether can be used as a kind of electrolyte solvent outside the above range.

In the present invention, LiMn ₂ O ₄ , LiM
Electrodes prepared using a manganese-containing oxide such as nO ₂ as a positive electrode active material or a negative electrode active material contain a binder, but in addition, auxiliary components such as a conductive auxiliary such as carbon black or graphite. May be included. Further, the electrode may include a metal current collector such as aluminum or stainless steel, but when aluminum is used as the current collector, LiN (R ₁ ) is used as an electrolyte.
_{(R 2) (R 1 =} C x F 2X + 1 SO 2, R 2 = C y F 2y + 1
SO ₂ , x + y ≧ 2) where x = y = 1 is used,
Elution of aluminum may be remarkable.

As the binder, for example, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, ethyl cellulose, polyethylene oxide, polyvinyl butyral, polymethyl methacrylate, polyethylene glycol, polypropylene glycol, ethylene propylene diene rubber, ethylene propylene rubber, styrene ethylene Butadiene styrene rubber, styrene butadiene styrene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, and the like,
These may be used alone or in combination of two or more.

In the present invention, LiMn ₂ O ₄ , LiM
When the working electrode is an electrode prepared using a manganese-containing oxide such as nO ₂ as a positive electrode active material, for example, a metal lithium, lithium alloy, carbon material, tin oxide, nitrogen oxide, or the like is used as an active material. Can be used. However, the counter electrode is not limited to those described above, and the counter electrode active material may be one using each of the above examples alone or a combination of two or more.

The structure of the counter electrode includes the above-described counter electrode active material and a binder, and also includes an auxiliary component such as a conductive auxiliary such as carbon black or graphite as in the case of the working electrode. It may include a metal current collector such as copper (Cu), nickel (Ni), iron (Fe), aluminum (Al), and stainless steel.

As the separator for separating the working electrode and the counter electrode, for example, a microporous polyethylene film,
Microporous polypropylene film, such as microporous polyethylene-polypropylene composite film,
Other than these may be used.

[0020]

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.

Example 1 20 g of polyvinylidene fluoride as a binder was mixed with N-
250 g of methyl-2-pyrrolidone was added, and the mixture was heated to 60 ° C. to dissolve polyvinylidene fluoride in N-methyl-2-pyrrolidone to prepare a binder solution. A specific surface area of 0.8 m ² / g as a positive electrode active material was added to this binder solution.
Of LiMn ₂ O ₄ was added, and 5 g of carbon black and 25 g of graphite were further added as conductive aids.
Stir to a slurry.

This slurry was uniformly applied to both sides of an aluminum foil having a thickness of 20 μm, dried, compression-molded by a roller press, and cut to obtain an average thickness of 19 μm.
A band-shaped positive electrode of 54 μm × 500 mm at 0 μm was prepared.
Since this positive electrode contains 12 g of LiMn ₂ O ₄ per sheet, the surface area of LiMn ₂ O ₄ per cell is 9.6 m ² .

Further, a binder solution similar to the above was prepared, and 180 g of graphite was added to the binder solution as a negative electrode active material, followed by stirring to form a slurry. This slurry was uniformly applied to both sides of a copper foil having a thickness of 18 μm, dried, compression-molded by a roller press, and then cut to obtain an average thickness of 140 μm and 56 mm × 520 mm.
Was produced.

Next, a separator made of a microporous polyethylene film having a thickness of 25 μm is disposed between the strip-shaped positive electrode and the strip-shaped negative electrode, and is spirally wound into a spiral electrode body. The battery was inserted into a bottom cylindrical battery case, and the positive electrode lead body and the negative electrode lead body were welded.

Then, 1.4M LiBF is placed in the battery case.
₄ / EC + MEC + DME (4 + 5 + 1) electrolytic solution [that is, Li in a mixed solvent of ethylene carbonate (EC), methyl ethyl carbonate (MEC) and 1,2-dimethoxyethane (DME) in a volume ratio of 4: 5: 1.
Electrolyte solution obtained by dissolving BF ₄ at 1.4 mol / L]
Was injected 4.0 cc. In this case, the amount of electrolyte per 1 m ² of surface area of LiMn ₂ O ₄ is 0.42 cc.

Next, the opening of the battery case was sealed in accordance with a conventional method to produce a cylindrical organic electrolyte secondary battery having the structure shown in FIG.

In the battery shown in FIG. 1, 1 is the positive electrode and 2 is the negative electrode. In FIG. 1, aluminum foil, copper foil, and the like used for producing the positive electrode 1 and the negative electrode 2 are not shown in order to avoid complication. Reference numeral 3 denotes a separator, 4 denotes an electrolytic solution, and 5 denotes a nickel-plated iron battery case. The details of the positive electrode 1, the negative electrode 2, the separator 3, and the electrolytic solution 4 are as described above. The battery case 5 also serves as a negative electrode terminal. An insulator 6 made of a polytetrafluoroethylene sheet is disposed at the bottom of the battery case 5, and an insulator 7 made of a polytetrafluoroethylene sheet is also provided at an inner peripheral portion. Are located.

The spiral electrode body composed of the positive electrode 1, the negative electrode 2 and the separator 3, the electrolyte 4 and the like are accommodated in the battery case 5. Reference numeral 8 denotes a sealing plate made of aluminum, and a gas vent hole 8a is provided in the center thereof. 9 is a packing made of polypropylene and 10 is a flexible thin plate made of aluminum. Reference numeral 11 denotes a heat deformable member made of polypropylene. The heat deformable member 11 is deformed by temperature, and has an action of changing a breaking pressure of the flexible thin plate 10. Reference numeral 12 denotes a terminal plate made of aluminum. The terminal plate 12 is provided with a cutting blade 12a and a gas discharge hole 12b, and gas is generated inside the battery to increase the internal pressure.
The pressure rise causes the flexible thin plate 10 to break, and the gas inside the battery is discharged to the outside of the battery through the gas discharge holes 12b, so that the battery is prevented from bursting under high pressure.

Reference numeral 13 denotes an insulating packing made of polypropylene, 14 denotes a lead body, and this lead body 14
And the sealing plate 8 are electrically connected, and the terminal plate 12 functions as a positive electrode terminal by contact with the sealing body 8. Also,
Reference numeral 15 denotes a lead body for electrically connecting the negative electrode 2 and the battery case 5.

Example 2 Specific surface area of 1.3 m ² / g as a positive electrode active material LiMn
₂ O ₄ (The surface area of LiMn ₂ O ₄ per battery is 1
5.6 m ² ) and 1.0 M LiBF ₄ as an electrolytic solution.
3.0 cc of / EC + MEC + THF (9 + 10 + 1)
Except for using, a cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1.

The electrolyte is described in detail. The electrolyte is ethylene carbonate (EC), methyl ethyl carbonate (MEC) and tetrahydrofuran (TH).
It is obtained by dissolving 1.0 mol / liter of LiBF _{4 in} a mixed solvent having a volume ratio of 9: 10: 1 with F). And
The amount of electrolyte per 1 m ² of surface area of LiMn ₂ O ₄ of the battery of Example 2 was 0.19 cc.

Example 3 Specific surface area of 1.3 m ² / g as positive electrode active material LiMn
₂ O ₄ (The surface area of LiMn ₂ O ₄ per battery is 1
5.6 m ² ) and 1.0 M LiN (C
_{2 F 5 SO 2) 2 /} EC + MEC + DME (4 + 5 +
A cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1 except that 4.0 cc of 1) was used.

The electrolyte is described in detail in a mixed solvent of ethylene carbonate (EC), methyl ethyl carbonate (MEC) and 1,2-dimethoxyethane (DME) in a volume ratio of 4: 5: 1. LiN
(C ₂ F ₅ SO ₂ ) ₂ dissolved in 1.0 mol / liter. And, in the battery of the third embodiment, L
The amount of electrolyte per 1 m ² of surface area of iMn ₂ O ₄ is 0.1
It was 7 cc.

Example 4 Specific surface area of 0.6 m ² / g as positive electrode active material LiMn
_{Using 2} O ₄ (the surface area of LiMn ₂ O ₄ per battery is 7.2 m ² ), 0.7 M LiN (C
F ₃ SO ₂ ) (C ₂ F ₅ SO ₂ ) / EC + MEC + DM
A cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1, except that 4.5 cc of E (7 + 10 + 3) was used.

The electrolyte is described in detail in a mixed solvent of ethylene carbonate (EC), methyl ethyl carbonate (MEC) and 1,2-dimethoxyethane (DME) in a volume ratio of 7: 10: 3. LiN
(CF ₃ SO ₂ ) (C ₂ F ₅ SO ₃ ) dissolved in 0.7 mol / liter. The amount of electrolyte per 1 m ² of surface area of LiMn ₂ O ₄ in the battery of Example 4 was 0.63 cc.

Example 5 Specific surface area of 1.3 m ² / g as a positive electrode active material LiMn
₂ O ₄ (The surface area of LiMn ₂ O ₄ per battery is 1
5.6 m ² ) and 1.0 M LiBF ₄ as an electrolytic solution.
Except that 3.0 cc of / EC + MEC (1 + 1) was used.
A cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1.

The electrolyte was described in detail. The electrolyte was prepared by dissolving 1.0 mol / liter of LiBF _{4 in} a mixed solvent of ethylene carbonate (EC) and methyl ethyl carbonate (MEC) at a volume ratio of 1: 1. Things. Then, LiMn ₂ in the battery of Example 5 was used.
The amount of electrolyte per 1 m ² of surface area of O ₄ was 0.19 cc.

Example 6 Specific surface area of 2.0 m ² / g as a positive electrode active material LiMn
₂ O ₄ (LiMn ₂ O ₄ per battery has a surface area of 2
4.0 m ² ) and 1.0 M LiN (C
_{2 F 5 SO 2) 2 /} EC + MEC (1 + 1) to 2.5c
A cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1, except that c was used.

The electrolyte is described in detail. The electrolyte is prepared by adding LiN (C ₂ F ₅ SO ₂ ) ₂ to a mixed solvent of ethylene carbonate (EC) and methyl ethyl carbonate (MEC) at a volume ratio of 1: 1. 0.0mol / liter. The amount of electrolyte per 1 m ² of surface area of LiMn ₂ O ₄ in the battery of Example 6 was 0.10 cc.

Comparative Example 1 Specific surface area of 0.8 m ² / g as a positive electrode active material LiMn
_{Using 2} O ₄ (the surface area of LiMn ₂ O ₄ per battery is 9.6 m ² ), 1.0 M LiPF ₆ was used as an electrolyte.
Except that 4.0 cc of / EC + MEC (1 + 1) was used.
A cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1.

The electrolyte was described in detail. The electrolyte was prepared by dissolving 1.0 mol / liter of LiPF _{6 in} a mixed solvent of ethylene carbonate (EC) and methyl ethyl carbonate (MEC) at a volume ratio of 1: 1. Things. The LiMn ₂ in the battery of Comparative Example 1
The amount of electrolyte per 1.0 m ² of surface area of O ₄ is 0.42 c
c.

Comparative Example 2 Specific surface area of 2.3 m ² / g as a positive electrode active material LiMn
₂ O ₄ (LiMn ₂ O ₄ per battery has a surface area of 2
7.6 m ² ) and 1.0 M LiN (C
_{2 F 5 SO 2) 2 /} EC + MEC (1 + 1) to 2.0c
A cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1, except that c was used.

The electrolytic solution will be described in detail. The electrolytic solution is prepared by adding LiN (C ₂ F ₅ SO ₃ ) ₂ to a mixed solvent of ethylene carbonate (EC) and methyl ethyl carbonate (MEC) at a volume ratio of 1: 1. 0.0mol / liter. The amount of electrolyte per 1.0 m ² of surface area of LiMn ₂ O ₄ in the battery of Comparative Example 2 was 0.07 cc.

Comparative Example 3 Specific surface area of 0.5 m ² / g as a positive electrode active material LiMn
_{Using 2} O ₄ (the surface area of LiMn ₂ O ₄ per battery is 6.0 m ² ), 0.7 M LiN (C
_{2 F 5 SO 2) 2 /} EC + MEC + DME (7 + 10 +
A cylindrical organic electrolyte secondary battery was produced in the same manner as in Example 1 except that 5.1 cc of 3) was used.

The above electrolyte is described in detail in a mixed solvent of ethylene carbonate (EC), methyl ethyl carbonate (MEC) and 1,2-dimethoxyethane (DME) in a volume ratio of 7: 10: 3. LiN
(C ₂ F ₅ SO ₂ ) ₂ dissolved in 0.7 mol / liter. L in the battery of Comparative Example 3
The amount of electrolyte solution per 1.0 m ² of surface area of iMn ₂ O ₄ was 0.85 cc.

With respect to the organic electrolyte secondary batteries of Examples 1 to 6 and Comparative Examples 1 to 3, a manganese dissolution test, storage characteristics, cycle characteristics and load characteristics were measured under the following conditions. The results are shown in Table 1 below. In addition, those test methods are as follows.

[Manganese Dissolution Test] The positive electrodes of Examples 1 to 6 and Comparative Examples 1 to 3 were cut into an electrode area of 3 m ^{2, and each} was cut together with 2 cc of the electrolytic solution of Examples 1 to 6 and Comparative Examples 1 to 3, respectively. After placing in a polytetrafluoroethylene bottle and storing at 60 ° C. for 5 days, the amount of manganese eluted into the electrolytic solution is measured by an atomic absorption method.

[Storage Characteristics] The organic electrolyte secondary batteries of Examples 1 to 6 and Comparative Examples 1 to 3 were charged and discharged for 10 cycles in the range of 4.2 V to 3.0 V. Measure and use it as the pre-storage capacity. Subsequently, the battery was charged to 4.2 V, stored at 60 ° C. for 20 days, and then the discharge capacity when discharged to 3.0 V was measured. Capacity before storage)
A capacity retention rate is determined by × 100 (%), and is set as a capacity retention rate that indicates storage characteristics.

[Cycle Characteristics] The organic electrolyte secondary batteries of Examples 1 to 6 and Comparative Examples 1 to 3 were used in the range of 4.2 V to 3.0.
Charge / discharge in the range of V
The discharge capacity at the 0th cycle was measured, and the retention rate of the discharge capacity at the 300th cycle with respect to the discharge capacity at the 1st cycle [(discharge capacity at the 300th cycle) / (discharge capacity at the first cycle) × 100 (%)] And calculate it as a cycle characteristic.

[Load Characteristics] The organic electrolyte secondary batteries of Examples 1 to 6 and Comparative Examples 1 to 3 were charged and discharged for 10 cycles in the range of 4.2 V to 3.0 V to stabilize the capacity.
Discharge was performed at a rate of 0.2 hour (0.2C) and a rate of 2 hours (2C), and the respective discharge capacities were measured. %), And use it as the capacity retention ratio indicating the load characteristics.

Table 1 shows the results of measuring the above characteristics of the organic electrolyte secondary batteries of Examples 1 to 6 and Comparative Examples 1 to 3.

[0052]

[Table 1]

As shown in Table 1, in Examples 1 to 6, the amount of manganese eluted was small, and all of the storage characteristics, cycle characteristics and load characteristics were excellent.

On the other hand, in Comparative Example 1, since LiPF ₆ was used as the electrolyte in accordance with the prior art, the amount of manganese eluted was increased, and the storage characteristics and cycle characteristics were poor. Comparative Example 2 is based on the active material LiMn.
0.07cc of electrolyte per 1m ² of surface area of ₂ O ₄
, The storage characteristics and the cycle characteristics slightly deteriorated. Comparative Example 3 shows that the active material L
The amount of electrolyte per 1 m ² of surface area of iMn ₂ O ₄ is 0.8
Since the amount was slightly as large as 5 cc, the amount of manganese eluted began to increase, and storage characteristics and cycle characteristics deteriorated.

[0055]

As described above, according to the present invention, in an organic electrolyte secondary battery using an oxide containing manganese as an active material, elution of manganese into the electrolyte is suppressed.
An organic electrolyte secondary battery having excellent storage characteristics and cycle characteristics was provided. In addition, by adding ether in the range of 1 to 15% by volume in the electrolyte solution solvent, the cycle characteristics could be further improved, and the load characteristics could be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one example of an organic electrolyte secondary battery of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Separator 4 Electrolyte

Claims (2)

[Claims] 1. An oxide containing manganese such as LiMn ₂ O ₄ or LiMnO ₂ is used as a positive electrode active material or a negative electrode active material, and LiBF ₄ and LiN (R ₁ ) (R ₂ ) (R
_{1 = C x F 2x + 1} SO 2, R 2 = C y F 2y + 1 SO 2, x +
y ≧ 2), in an organic electrolyte secondary battery using a solution obtained by dissolving one or more kinds selected from organic solvents in an organic solvent, the electrolyte is reduced to 0 per 1 m ² of the surface area of the active material. An organic electrolyte secondary battery using 0.08 cc to 0.8 cc. 2. The organic electrolyte secondary battery according to claim 1, wherein the electrolyte solvent of the electrolyte solution contains 1 to 15% by volume of ether.