JP2003068282A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery of high safety with high capacity and high output. SOLUTION: A positive electrode active material mixture is made by mixing lithium manganate powder of spinel crystal structure, which has Li/Mn ratio of 0.52 and a mean particle diameter of about 20 μm, flake graphite of a mean particle diameter of 18 μm, and PVDF or thermosetting plasticized polyvinyl alcohol in the mixing ratio of 85:10:5 to 85:12:3. NMP as dispersing solvent is added to the positive electrode active material mixture to be kneaded, the resultant slurry is coated on the both surfaces of an aluminum foil of 20 μm in thickness to obtain spread of lithium manganate of 80-160 g/m<2> . The heating value, followed on the chemical reaction between the nonaqueous electrolyte and the positive electrode active material mixture, is reduced, and sharp and large volume of gas generation is controlled in a cylindrical lithium ion battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte secondary battery, and more particularly to a strip-shaped current collector containing a positive electrode active material mixture containing a lithium manganese oxide having a spinel type crystal structure, a conductive material and a binder. A positive electrode coated on both sides of the body in a substantially equal amount, and a negative electrode mixture consisting of a carbonaceous material capable of absorbing and releasing lithium ions by charging and discharging, a binder, and a conductive material are formed on both sides of the strip-shaped current collector. The present invention relates to a non-aqueous electrolyte secondary battery in which a negative electrode coated with an equal amount of the negative electrode and an electrode winding group wound through a separator are housed in a battery container having an internal pressure releasing mechanism that releases the internal pressure at a predetermined pressure.

[0002]

2. Description of the Related Art Lithium ion secondary batteries, which are representative of non-aqueous electrolyte secondary batteries, are mainly used for powering portable devices such as VTR cameras, laptop computers, and mobile phones by taking advantage of their high energy density. Has been done. The internal structure of this battery is usually of the wound type as shown below. Both the positive electrode and the negative electrode have a strip shape in which the active material is applied to the metal foil, and the cross section is spirally wound to form a winding group so that the positive electrode and the negative electrode do not come into direct contact with each other with the separator interposed therebetween. . This winding group is housed in a cylindrical battery can that serves as a battery container, and after the electrolytic solution is injected, it is sealed.

The size of a general cylindrical lithium ion secondary battery is called 18650 type and has a diameter of 18 mm and a height of 65 mm, and is widely used as a small consumer lithium ion battery. Lithium cobalt oxide, which is characterized by high capacity and long life, is mainly used for the positive electrode active material of 18650 type lithium ion secondary battery, the battery capacity is about 1.3 Ah to 1.8 Ah, and the output is about 10 W. It is a degree.

On the other hand, in the automobile industry, in order to cope with environmental problems, an electric vehicle without exhaust gas, which uses only a battery as a power source, and a hybrid which uses both an internal combustion engine and a battery as power sources ( The development of electric vehicles has accelerated, and some of them are in the stage of practical application.

Naturally, a battery serving as a power source of an electric vehicle is required to have a characteristic that a high output and a high energy can be obtained, and a lithium ion battery attracts attention as a battery which meets the requirement. In order to popularize electric vehicles, it is essential to reduce the price of batteries. For that reason, low-cost battery materials are required. For example, in the case of positive electrode active materials, manganese oxide, which is rich in resources, is particularly desirable. Attention has been paid to improvements aimed at improving the performance of batteries. In addition, as a battery for an electric vehicle, not only high capacity but also high output that affects acceleration performance and the like, that is, reduction of internal resistance of the battery is required. Further, it is required to extend the life of the battery in order to cope with a long use period of the electric vehicle. The term “longer life” means that not only the battery capacity but also a decrease in output is suppressed and the electric energy supply capacity necessary for running the electric vehicle is satisfied for a long period of time.

[0006]

However, in the case of a lithium ion battery, the higher the capacity and the higher the output, the lower the safety tends to be. Especially, in the case of the battery with a large output, the battery is in an abnormal state. There is a tendency that the phenomenon when it falls is a little more intense. A battery with a high capacity and a high output, such as that used in a power supply for an electric vehicle, is charged with a large amount of current and discharged with a large amount of current. It is virtually impossible to provide a current interruption mechanism (a kind of disconnection switch) in the battery structure that operates in response to an increase in internal pressure.

In the case of an electric vehicle that carries passengers, during overcharging when the charging control system fails, when a battery crashes that may occur during an accidental collision, or when a foreign object is stabbed. Securing the safety of the battery itself at the time of an external short circuit is a minimum and very important battery characteristic. Battery safety means that the behavior of a battery when it is exposed to abnormal conditions does not cause any physical damage to humans, but it also minimizes damage to the vehicle. Means

In view of the above problems, it is an object of the present invention to provide a non-aqueous electrolyte secondary battery which has a high capacity and a high output but is extremely safe.

[0009]

In order to solve the above-mentioned problems, the present invention provides a strip-shaped current collector containing a positive electrode active material mixture containing a lithium manganese oxide having a spinel type crystal structure, a conductive material and a binder. On both sides of the strip-shaped current collector, there is a positive electrode coated on both sides in a substantially equal amount, and a negative electrode mixture consisting of a carbonaceous material capable of absorbing and releasing lithium ions by charging and discharging, a binder and a conductive material. A negative electrode coated in an amount, and an electrode winding group wound via a separator, a non-aqueous electrolyte secondary battery housed in a battery container having an internal pressure release mechanism for releasing the internal pressure at a predetermined pressure, The amount of lithium manganese oxide coated on one side of the current collector is 80 g / m.
^{2 to} 160 g / m ² , and the mass of the conductive material is 10 mass% to 12 mass% of the positive electrode active material mixture,
Moreover, the mass of the binder is 3 mass% of the positive electrode active material mixture.
To 5% by mass.

In the present invention, in order to secure a high capacity, high output non-aqueous electrolyte secondary battery, a positive electrode active material mixture containing a lithium manganese composite oxide having a spinel type crystal structure, a conductive material and a binder. There is used a positive electrode in which approximately equal amounts are coated on both surfaces of a strip-shaped current collector, and a negative electrode capable of absorbing and releasing lithium ions by charging and discharging. A high-capacity, high-output non-aqueous electrolyte secondary battery maintains a high-current charge or high-current discharge state when an abnormal state occurs, and is accompanied by a chemical reaction between the non-aqueous electrolyte and the active material mixture. Due to the heat generation, a large amount of gas is rapidly generated in the battery container, increasing the internal pressure of the battery container. Generally, a non-aqueous electrolyte secondary battery has an internal pressure release mechanism for releasing the internal pressure at a predetermined pressure in the battery container in order to prevent an increase in the internal pressure in the battery container. 80 g / m ² of coating amount per side of electric body
To 160 g / m ² and the mass of the conductive material is 10% by mass to 12% by mass of the positive electrode active material mixture, the calorific value can be reduced, so that gas release from the internal pressure release mechanism can be achieved. It is extremely gentle. Further, the mass of the binder is 3% by mass to 5% by mass of the positive electrode active material mixture.
By this, peeling and dropping of the positive electrode active material mixture can be prevented, so that reduction in initial capacity and output can be suppressed. Therefore, according to the present invention, a high capacity,
It is possible to realize a highly safe non-aqueous electrolyte secondary battery while having high output.

In this case, if a mixture of graphite and amorphous carbon is used as the conductive material, a higher output non-aqueous electrolyte secondary battery can be obtained. At this time, the mass of graphite and amorphous carbon is increased. If the ratio is 80:20 to 90:10, the output can be further increased. Further, when the average particle size of graphite is 0.2 to 0.8 times the average particle size of lithium manganese composite oxide having a spinel type crystal structure, a non-aqueous electrolyte secondary battery with higher output is obtained. When acetylene black is used as the amorphous carbon, a non-aqueous electrolyte secondary battery with higher output can be obtained. Furthermore, if the Li / Mn ratio of the lithium manganese oxide is set to 0.55 to 0.60, the output retention rate can be improved without a decrease in capacity. In addition, lithium manganese mixed oxide
i _{1 + x} Mn _{2−x− y My} O ₄ (x is 0 <x ≦ 0.
1, y is 0 <y ≦ 0.3, M is A1, Cr, Ni, C
If it is represented by at least one element selected from the group consisting of o and Mg), the output retention rate can be improved without lowering the capacity. Furthermore, when amorphous carbon is used as the active material of the negative electrode, a non-aqueous electrolyte secondary battery having high output and high capacity and further excellent safety can be obtained.

Further, if a thermosetting plasticized polyvinyl alcohol resin mainly composed of polyvinyl alcohol is used for the binder of the positive electrode and / or the negative electrode, the output retention rate can be improved without further lowering the capacity. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the non-aqueous electrolyte secondary battery according to the present invention is applied to a cylindrical lithium ion battery for a hybrid electric vehicle will be described below with reference to the drawings.

(Preparation of Thermosetting Plasticized Polyvinyl Alcohol Resin Binder Composition) The thermosetting plasticized polyvinyl alcohol resin comprises a first resin component composed of a thermosetting polyvinyl alcohol resin and an acrylic resin plasticizer. The second resin component was mixed and dissolved in an appropriate solvent (in this example, N-methyl-2-pyrrolidone, hereinafter referred to as NMP). The thermosetting polyvinyl alcohol-based resin, which is the first resin component, is a polyvinyl alcohol-based resin having an average degree of polymerization of about 2000 and a cyclic acid anhydride such as succinic anhydride, NMP.
It can be obtained by reacting in a substantially anhydrous state in the presence of a catalyst such as triethylamine in an organic solvent such as. The reaction ratio between the polyvinyl alcohol-based resin and the cyclic acid anhydride is preferably about 0.1 equivalent of the anhydride group of the cyclic acid anhydride to 1 equivalent of the alcoholic hydroxyl group of the polyvinyl alcohol-based resin.

As the acrylic resin type plasticizer which is the second resin component, a reaction product of a lauryl acrylate / acrylic acid copolymer and a bifunctional epoxy resin is suitable.

The thermosetting plasticized polyvinyl alcohol resin composition used in this embodiment was synthesized as follows.

The first resin component was synthesized as follows.
To a separable flask equipped with a stirrer, a thermometer, a cooling pipe, a distilling distillate, and a nitrogen gas introduction pipe, 51 g of polyvinyl alcohol having a saponification degree of about 98%, 650 g of NMP, and 10 g of toluene were charged, and nitrogen bubbling and stirring were performed. The temperature was raised to 195 ° C over about 30 minutes. The temperature was kept at the same temperature for 2 hours, and toluene was refluxed to azeotropically distill the water, and the water in the flask was distilled off. Then, toluene was distilled off, the mixture was cooled to 120 ° C, and while maintaining the temperature at the same temperature, 7.7 g of succinic anhydride was added and reacted for 1 hour (for 1 equivalent of alcoholic hydroxyl group of polyvinyl alcohol, acid Anhydrous groups are about 0.07 eq.). It cooled to room temperature and obtained the NMP solution whose 1st resin component is about 8 mass%.

The second resin component was synthesized as follows.
In a separable flask equipped with a stirrer, a thermometer, a cooling pipe, a distilling distillate, and a nitrogen gas introducing pipe, a weight average molecular weight of about 310
0, 110 g of solventless lauryl acrylate / acrylic acid copolymer, and bisphenol A type epoxy resin 71
g (about 2 equivalents as an epoxy group to 1 equivalent of a carboxyl group of a solvent-free lauryl acrylate / acrylic acid copolymer) was added, and the temperature was raised to 150 ° C over about 15 minutes while nitrogen bubbling and stirring were performed. did. After incubating for 2 hours at the same temperature to proceed the reaction, add 78 g of NMP here,
When cooled to room temperature, the second resin component contains about 70% by weight of N 2.
An MP solution was obtained.

An NMP solution containing 8% by weight of the first resin component and an NMP solution containing about 70% by weight of the second resin component were mixed at a ratio of 100: 10 in terms of the weight of each resin component,
NM of thermosetting plasticized polyvinyl alcohol resin composition
A P solution was obtained.

(Preparation of Positive Electrode Plate) Lithium manganate powder as a lithium manganese oxide having a spinel type crystal structure, and a predetermined carbon material described below as a conductive material,
Polyvinylidene fluoride (P) as a binder
NM of VDF) or thermosetting plasticized polyvinyl alcohol resin (hereinafter referred to as thermosetting plasticized PVA) composition
If necessary, N-methyl-2-pyrrolidone (NMP) as a dispersion solvent was added to the positive electrode active material mixture prepared by mixing the P solution and the mixture at a predetermined mixing ratio to obtain a kneaded slurry. At this time, the amount of the carbon material was 10 to 12% by mass of the positive electrode active material mixture, and the amount of the binder was 3 to 5% by mass of the positive electrode active material mixture. The produced slurry was applied to both surfaces of an aluminum foil (positive electrode current collector) having a thickness of 20 μm, and the coating amount of lithium manganate per one surface of the positive electrode current collector was 80 to 160 g / m ^2.
Was applied. At this time, an uncoated portion having a width of 30 mm was left on one side edge in the lengthwise direction of the positive electrode plate. Then dry, press,
By cutting, a positive electrode plate having a width of 82 mm, a predetermined length, and a predetermined thickness of the positive electrode active material mixture application portion was obtained. The bulk density of the positive electrode active material mixture layer was 2.65 g / cm ³ . A notch was made in the uncoated portion, and the remaining notch was used as a positive electrode lead piece. Adjacent positive electrode lead pieces were spaced 50 mm apart, and the width of the positive electrode lead pieces was 5 mm.

(Preparation of Negative Electrode Plate) Graphite powder (hereinafter referred to as MCMB) manufactured by Osaka Gas Chemical Co., Ltd., which is mesophase type spherical graphite, or amorphous carbon manufactured by Kureha Chemical Industry Co., Ltd., which is a negative electrode active material. 92 parts by mass of carbon powder (trade name: Carbotron P) (hereinafter referred to as PIC), 8 parts by mass of PVDF, or thermosetting plasticized PVA
NMP solution as a resin component was added so as to be 8 parts by mass, and if necessary, NMP as a dispersion solvent was added.
Was added and kneaded to apply the slurry to both surfaces of a rolled copper foil (negative electrode current collector) having a thickness of 10 μm. At this time, an uncoated portion having a width of 30 mm was left on one side edge in the lengthwise direction of the negative electrode plate. Then, it was dried, pressed, and cut to obtain a negative electrode plate having a width of 86 mm, a predetermined length, and a predetermined thickness of the negative electrode active material mixture application portion. The negative electrode plate was compressed so that the porosity of the negative electrode active material mixture layer was about 35%. The negative electrode using the thermosetting plasticized PVA as a binder was then subjected to vacuum drying / heat treatment at 150 ° C. for 16 hours for thermosetting. A notch was made in the uncoated portion similarly to the positive electrode, and the remaining notch was used as a negative electrode lead piece. Adjacent negative electrode lead pieces were spaced at 50 mm, and the width of the negative electrode lead pieces was 5 mm.

Further, in the produced electrode plate, when wound as described later, the positive electrode plate does not protrude from the negative electrode plate in the winding direction at the innermost winding periphery, and also in the winding direction at the outermost periphery. The length of the negative electrode plate was 12 cm longer than the length of the positive electrode plate so that the positive electrode plate did not protrude from the negative electrode plate. Further, the width of the negative electrode active material mixture coating portion is set so that the positive electrode active material mixture coating portion does not protrude from the negative electrode active material mixture coating portion even in the direction perpendicular to the winding direction. It was 4 mm longer than the width of the part.

(Preparation of Battery) As shown in FIG. 1, the above-prepared positive electrode plate and negative electrode plate were wound together with a polyethylene separator W5 having a width of 90 mm and a thickness of 40 μm so as not to directly contact the both electrode plates. . A hollow cylindrical shaft core 1 made of polypropylene was used as the center of winding. At this time, the positive electrode lead piece and the negative electrode lead piece were respectively positioned on opposite end surfaces of the winding group (electrode winding group) 6 on opposite sides. The lengths of the positive electrode plate, the negative electrode plate, and the separator were adjusted so that the winding group 6 had a diameter of 38 ± 0.1 mm.

The positive electrode lead pieces are deformed, and all of them are gathered and contacted in the vicinity of the peripheral surface of the flange portion which is integrally projected from the periphery of the positive electrode current collecting ring which is almost on the extension line of the axis 1 of the winding group 6. Then, the positive electrode lead piece and the peripheral surface of the flange portion were ultrasonically welded to connect the positive electrode lead piece to the peripheral surface of the flange portion. On the other hand, the operation of connecting the negative electrode current collecting ring and the negative electrode lead piece was performed in the same manner as the operation of connecting the positive electrode current collecting ring and the positive electrode lead piece.

After that, an insulating coating was applied to the entire circumference of the flange portion of the positive electrode current collecting ring. For this insulating coating, an adhesive tape was used in which the base material was polyimide, and one surface of which was coated with an adhesive consisting of hexamethacrylate. The adhesive tape was wound over the outer peripheral surface of the winding group 6 from the flange peripheral surface to form an insulating coating, and the winding group 6 was inserted into a nickel-plated steel battery container 7. The outer diameter of the battery container 7 is 4
The inner diameter is 0 mm and the inner diameter is 39 mm.

A negative electrode lead plate for electrical conduction is previously welded to the negative electrode current collecting ring. After the winding group 6 is inserted into the battery container 7, the bottom of the battery container 7 and the negative electrode lead plate are welded. did.

On the other hand, the positive electrode current collector ring is previously welded with a positive electrode lead formed by stacking a plurality of aluminum ribbons, and the other end of the positive electrode lead is attached to the battery container 7
Was welded to the lower surface of the battery lid for sealing. The battery lid is provided with a cleaving valve 11 as an internal pressure releasing mechanism that cleaves in accordance with an increase in the internal pressure of the cylindrical lithium ion battery 20. The cleavage pressure of the cleavage valve 11 was set to about 9 × 10 ⁵ Pa. The battery lid has a lid case, a valve retainer that keeps airtightness,
It is composed of a cleaving valve (internal gas discharge valve) 11, and these are laminated and assembled by caulking the peripheral edge of the lid case.

A predetermined amount of non-aqueous electrolyte is injected into the battery container 7, and then the battery container 7 is covered with a battery cover so that the positive electrode lead is folded, and the battery container 7 is caulked and sealed with an EPDM resin gasket. Thus, the cylindrical lithium ion battery 20 was completed.

As the non-aqueous electrolyte, lithium hexafluorophosphate (L) is added to a mixed solution of ethylene carbonate, dimethyl carbonate and diethyl carbonate at a volume ratio of 1: 1: 1.
iPF ₆ ) was used at a concentration of 1 mol / liter.
It should be noted that the cylindrical lithium-ion battery 20 is electrically operated in accordance with an increase in battery temperature, for example, a PTC (Posi
Neither a tive temperature coefficient (COT) element nor a current interruption mechanism for cutting the electric lead of the positive electrode or the negative electrode according to the increase of the internal pressure of the battery is provided.

According to this embodiment, a positive electrode coated with lithium manganate having a spinel type crystal structure, a carbon material and a positive electrode active material mixture containing PVDF or thermosetting plasticized PVA, and lithium ions by charging and discharging. By using a negative electrode that uses graphite powder or amorphous carbon powder capable of occluding and releasing as a negative electrode active material, it is possible to secure a lithium ion battery with high capacity and high output. The amount of lithium manganate applied is 80 to 160 g / m per one side of the positive electrode current collector.
² and the amount of carbon material is 10 to 12 of the positive electrode active material mixture.
By setting the content to be% by mass, the amount of heat generated by the chemical reaction between the non-aqueous electrolyte and the positive electrode active material mixture can be reduced, and rapid and large amount of gas generation in the cylindrical lithium ion battery 20 can be suppressed. Therefore, the gas is released very gently from the cleaving valve 11 provided to prevent the internal pressure of the battery from rising. Furthermore, by setting the amount of PVDF to 3 to 5% by mass of the positive electrode active material mixture, peeling and dropping of the positive electrode active material mixture can be prevented, so that reduction in initial capacity and output can be suppressed. . Therefore, the manufactured cylindrical lithium-ion battery 20 is a battery having high capacity and high output, but extremely high safety.

[0031]

EXAMPLES Next, examples of the cylindrical lithium-ion battery 20 manufactured according to this embodiment will be described. The battery of the comparative example prepared for comparison is also shown.

Example 1 As shown in Table 1 below, in Example 1, the atomic ratio of Li and Mn (Li / Mn ratio) was 0.5.
2. Lithium manganate (Li having an average particle size of about 20 μm)
_{85 1 + x Mn 2-x} O 4) powder, a mixing ratio of average particle size 18μm of flake graphite and PVDF in a mass%: 11: 4
Then, the coating amount of lithium manganate per one side of the aluminum foil is 80 g / m ² , and the thickness of the positive electrode active material mixture application portion (excluding the thickness of the aluminum foil) (hereinafter referred to as the positive electrode application portion thickness). .) And the length of the positive electrode plate is 438.
cm. The average particle size of the flake graphite is 0.9 times the average particle size of lithium manganate. MCMB, which is mesophase spheroidal graphite, was used as the negative electrode active material, and PVDF was used as the negative electrode binder, and the thickness of the negative electrode active material mixture coating portion (excluding the thickness of the copper foil) (hereinafter, the negative electrode coating portion thickness) was used. The length of the negative electrode plate was 450 cm. The average particle size of the flake graphite can be adjusted by sieving and classification (hereinafter, the same applies to Examples and Comparative Examples unless otherwise specified).

[0033]

[Table 1]

Example 2 As shown in Table 1, Example 2
Then, the coating amount of lithium manganate is 120 g / m ² , the thickness of the positive electrode coating portion is 107 μm, and the length of the positive electrode plate is 34 μm.
5 cm, the thickness of the negative electrode coating part is 79 μm, and the length of the negative electrode plate is 3
The same procedure was performed as in Example 1 except that the length was 57 cm.

(Example 2-a) As shown in Table 1, in Example 2-a, a battery was produced in the same manner as in Example 2 except that thermosetting plasticized PVA was used as the positive electrode binder.

(Example 2-B) As shown in Table 1, in Example 2-B, a battery was prepared in the same manner as in Example 2 except that the thermosetting plasticized PVA was used as the negative electrode binder.

(Example 2-C) As shown in Table 1, in Example 2-C, a battery was prepared in the same manner as in Example 2 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. .

(Example 2-a) As shown in Table 1, in Example 2-a, the compounding ratio of lithium manganate powder, flake graphite and PVDF was 86: 11: 3, and the thickness of the positive electrode coating portion was Was 106 μm, and the thickness of the negative electrode coating portion was 80 μm.

(Example 2-b) As shown in Table 1, in Example 2-b, the compounding ratio of lithium manganate powder, scaly graphite and PVDF was 84: 11: 5, and the thickness of the positive electrode coating portion was Was 108 μm, the length of the positive electrode plate was 343 cm, the thickness of the negative electrode coating portion was 80 μm, and the length of the negative electrode plate was 355 cm.

(Examples 2-2 to 2-5) As shown in Table 1, in Examples 2-2 to 2-5, the Li / Mn ratio of lithium manganate was changed from that in Example 2-2. Example 2 was the same as Example 2 except that the value was 0.55, the value was 0.58 in Example 2-3, the value was 0.60 in Example 2-4, and the value was 0.61 in Example 2-5.

Example 3 As shown in Table 1, Example 3
Then, the coating amount of lithium manganate is 160 g / m ² , the thickness of the positive electrode coating portion is 142 μm, and the length of the positive electrode plate is 28 μm.
4 cm, the thickness of the negative electrode coating portion was 106 μm, and the length of the negative electrode plate was 296 cm, and the same procedure as in Example 1 was performed.

Example 4 As shown in Table 1, Example 4
Then, lithium manganate powder, flake graphite and PVD
The compounding ratio of F is 87: 8: 5, the coating amount of lithium manganate is 120 g / m ² , and the thickness of the positive electrode coating portion is 105 μ.
m, the length of the positive electrode plate was 347 cm, the thickness of the negative electrode coating portion was 79 μm, and the length of the negative electrode plate was 359 cm.

(Example 5) As shown in Table 1, Example 5
Then, lithium manganate powder, flake graphite and PVD
The compounding ratio of F is 84: 12: 4, the coating amount of lithium manganate is 120 g / m ² , and the thickness of the positive electrode coating portion is 108 μ.
m, the length of the positive electrode plate was 343 cm, the thickness of the negative electrode coating portion was 80 μm, and the length of the negative electrode plate was 355 cm.

Example 6 As shown in Table 1, Example 6 was used.
Then, a mixture of flake graphite and amorphous carbon Ketjen Black (hereinafter referred to as KB) is used as the carbon material,
Lithium manganate powder, flake graphite, KB and PVD
The compounding ratio of F was 85: 8.25: 2.75: 4, the amount of lithium manganate applied was 120 g / m ² , the thickness of the positive electrode coating part was 107 μm, the length of the positive electrode plate was 345 cm, and the negative electrode was applied. Same as Example 1 except that the thickness of the portion was 79 μm and the length of the negative electrode plate was 357 cm. The total blending amount of graphite and KB was 11% by mass, and the mass ratio of graphite and KB was 75:
25.

(Example 6-a) As shown in Table 1, in Example 6-a, a battery was prepared in the same manner as in Example 6 except that thermosetting plasticized PVA was used as the positive electrode binder.

(Example 6-b) As shown in Table 1, in Example 6-b, a battery was produced in the same manner as in Example 6 except that the thermosetting plasticized PVA was used as the negative electrode binder.

(Example 6-C) As shown in Table 1, in Example 6-C, a battery was prepared in the same manner as in Example 6 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. .

(Examples 6-1 to 6-4) As shown in Table 2 below, in Examples 6-1 to 6-4, lithium manganate powder, scaly graphite, KB and PVDF were used. Same as Example 6 except that the compounding ratio was changed. The compounding ratio was 85: 8.8: 2.2: 4 in Example 6-1 (the mass ratio of graphite and KB was 80:20), and in Example 6-2, 85: 9.35: 1. 65: 4 (mass ratio of graphite and KB is 85:15), and in Example 6-3, 85: 9.
9: 1.1: 4 (the mass ratio of graphite and KB is 90:10), and in Example 6-4, 85: 10.45: 0.55:
4 (the mass ratio of graphite and KB is 95: 5).

[0049]

[Table 2]

(Example 6-2-a) As shown in Table 2,
In Example 6-2-a, a battery was produced in the same manner as in Example 6-2 except that thermosetting plasticized PVA was used as the positive electrode binder.

(Example 6-2-b) As shown in Table 2,
In Example 6-2-B, a battery was produced in the same manner as in Example 6-2 except that the thermosetting plasticized PVA was used as the negative electrode binder.

(Example 6-2-C) As shown in Table 2,
In Example 6-2-C, a battery was produced in the same manner as in Example 6-2 except that thermosetting plasticized PVA was used for the positive electrode and the negative electrode binder.

Example 7 As shown in Table 2, Example 7
Then, using flake graphite having an average particle diameter of 2 μm, the compounding ratio of lithium manganate powder, flake graphite, KB and PVDF is 85: 9.35: 1.65: 4 (the mass ratio of graphite and KB is 85: Same as Example 6 except that it was set as 15).
The average particle size of the flake graphite is 0.1 times the average particle size of lithium manganate.

(Examples 8 to 10) As shown in Table 2, Examples 8 to 10 were the same as Example 7 except that flake graphite having different average particle diameters was used. Example 8
In Example 9, scaly graphite having an average particle size of 4 μm (0.2 times the average particle size of lithium manganate) was used, and in Example 9, scaly graphite having an average particle size of 10 μm (average particle size of lithium manganate). In Example 10, scaly graphite having an average particle size of 16 μm (0.8 times the average particle size of lithium manganate) was used.

Example 9-a As shown in Table 2, in Example 9-a, a battery was produced in the same manner as in Example 9 except that thermosetting plasticized PVA was used as the positive electrode binder.

(Example 9-b) As shown in Table 2, in Example 9-b, a battery was produced in the same manner as in Example 9 except that thermosetting plasticized PVA was used as the negative electrode binder.

(Example 9-C) As shown in Table 2, in Example 9-C, a battery was prepared in the same manner as in Example 9 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. .

Example 11 As shown in Table 2 below, in Example 11, a mixture of flake graphite and acetylene black of amorphous carbon (hereinafter referred to as AB) was used as the carbon material, and lithium manganate was used. Powder, flaky graphite having an average particle size of 10 μm (0.
5 times), and the mixing ratio of AB and PVDF is 85: 9.35:
1.65: 4 (the mass ratio of graphite and AB is 85:15), the coating amount of lithium manganate is 120 g / m ² , the thickness of the positive electrode coating portion is 107 μm, the length is 345 cm, and the negative electrode coating portion thickness is The same as Example 1 except that the length was 79 μm and the length was 357 cm.

(Example 11-a) As shown in Table 2, in Example 11-a, thermosetting plasticized PV was used as the positive electrode binder.
A battery was produced in the same manner as in Example 11 except that A was used.

(Example 11-b) As shown in Table 2, in Example 11-b, a thermosetting plasticized PV was used as the negative electrode binder.
A battery was produced in the same manner as in Example 11 except that A was used.

(Example 11-C) As shown in Table 2, in Example 11-C, a battery was prepared in the same manner as in Example 11 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. .

(Examples 12 to 15) As shown in Table 3 below, in Examples 12 to 15, the Li / Mn ratio of lithium manganate was set to 0.55 in Example 12,
In Example 13, 0.58, and in Example 14, 0.60
Example 11 except that in Example 15 0.61
Same as.

[0063]

[Table 3]

(Example 13-a) As shown in Table 3, in Example 13-a, a thermosetting plasticized PV was used as the positive electrode binder.
A battery was produced in the same manner as in Example 13 except that A was used.

(Example 13-b) As shown in Table 3, in Example 13-b, thermosetting plasticized PV was used as the negative electrode binder.
A battery was produced in the same manner as in Example 13 except that A was used.

(Example 13-C) As shown in Table 3, in Example 13-C, a battery was prepared in the same manner as in Example 13 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. .

(Examples 15-A to 15-N) Table 3
And as shown in Table 4 below, Example 15-A to Example 15
In -N, a part of manganese atom is replaced with another metal element M.
Lithium manganate having an average particle size of about 20 μm (Li
_{1 + x}Mn_2-xyM_yO_Four) Except for using powder
Same as Example 11. In Example 15-A, Li
_1.01Mn_1.79Cr_0.2O_FourExample 1
Li in 5-B_1.04Mn_1.76Cr_0.2O_FourTo
Used in Example 15-C._1.1Mn_1.7Cr
_0.2O_FourIs used in Example 15-D._1.11.M
n_1.69Cr_0.2O_FourIs used in Example 15-E
Li_{1. 04}Mn_1.95Cr_0.01O_FourUsing
In Example 15-F, Li_1.04Mn_1.66Cr_0.3
O_FourIs used in Example 15-G._1.04Mn
_{1.6 Three}Cr_0.33O_FourIs used in Example 15-H
Li_1.04Mn_1.76Al _0.2O_FourUsing
In Example 15-I, Li_1.04Mn_1.76Ni_0.2O
_FourIs used in Example 15-J._1.04Mn
_1.76Co_0.2O_FourIs used in Example 15-K.
i_1.04Mn_1.76Mg_0.2O_FourExample
Li in 15-L_1.04Mn_1.76(AlCr)
_0.2O_FourIs used in Example 15-M._1.04M
n_1.76(CrMg)_0.2O_FourExample 15
-N is Li_1.04Mn_1.76(CoMg)_0.2
O_FourWas used. In addition, element substitution type lithium manganate
Is manganese dioxide and a carbonate of the substituting metal element M,
Mix with nitrates, hydroxides, etc. to obtain the desired element ratio.
And bake in air at 800 ° C to 900 ° C.
Can be prepared by
The element ratio in lithium manganate was dissolved in hydrochloric acid, etc.
After that, titration method and atomic absorption and ICP analysis
It can be determined by quantitative analysis.

[0068]

[Table 4]

(Example 15-J-A) As shown in Table 4, Example 15-J-A was the same as Example 15-J except that thermosetting plasticized PVA was used as the positive electrode binder. A battery was made.

Example 15-J-B As shown in Table 4, Example 15-J-B was the same as Example 15-J except that thermosetting plasticized PVA was used as the negative electrode binder. A battery was made.

(Example 15-J-C) As shown in Table 4, in Example 15-J-C, as Example 15-J, except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. A battery was similarly prepared.

(Example 15-N-a) As shown in Table 4, Example 15-N-A was the same as Example 15-N except that thermosetting plasticized PVA was used as the positive electrode binder. A battery was made.

(Example 15-N-B) As shown in Table 4, Example 15-N-B was the same as Example 15-N except that thermosetting plasticized PVA was used as the negative electrode binder. A battery was made.

(Example 15-N-C) As shown in Table 4, Example 15-N-C was the same as Example 15-N except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. A battery was similarly prepared.

Example 16 As shown in Table 4, Example 16 was the same as Example 11 except that PIC which was amorphous carbon was used as the negative electrode active material.

(Example 16-a) As shown in Table 4, in Example 16-a, thermosetting plasticized PV was used as the positive electrode binder.
A battery was produced in the same manner as in Example 16 except that A was used.

(Example 16-b) As shown in Table 4, in Example 16-b, the thermosetting plasticized PV was used as the negative electrode binder.
A battery was produced in the same manner as in Example 16 except that A was used.

(Example 16-C) As shown in Table 4, in Example 16-C, a battery was prepared in the same manner as in Example 16 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. .

(Examples 16-2 to 16-5) As shown in Table 4, in Examples 16-2 to 16-5, the Li / Mn ratio of lithium manganate was changed from that in Example 16-2. 0.55, 0.58 in Example 16-3, 0.60 in Example 16-4, and 0.
Same as Example 16 except 61 was used.

(Example 16-3-A) As shown in Table 4, in Example 16-3-A, the same as Example 16-3 except that thermosetting plasticized PVA was used as the positive electrode binder. A battery was made.

(Example 16-3-b) As shown in Table 4, in Example 16-3-b, the same as Example 16-3 except that thermosetting plasticized PVA was used as the negative electrode binder. A battery was made.

(Example 16-3-C) As shown in Table 4, Example 16-3-C was the same as Example 16-3 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. A battery was similarly prepared.

(Examples 16-A to 16-N) Tables below
As shown in Example 5, in Examples 16-A to 16-N,
Is a flat manganese atom in which some of the manganese atoms are replaced by another metal element M.
Lithium manganate with a uniform particle size of about 20 μm (Li1 + xM
n2-x-yMyO4) Example 16 except that the powder was used.
Same as. In Example 16-A, Li_1.01Mn
_1.79Cr_0.2O_FourIs used in Example 16-B.
i_1.04Mn_1.76Cr_0.2O_FourExample
Li in 16-C_1.1Mn_1.7Cr_0.2O_FourFor
In Example 16-D, Li_{1. 11}Mn_1.69Cr
_0.2O_FourIs used in Example 16-E._1.04M
n _1.95Cr_0.01O_FourIn Example 16-F
Is Li_1.04Mn_{1.6 6}Cr_0.3O_FourUsing
In Example 16-G, Li_1.04Mn_1.63Cr_{0
． 33}O_FourIn Example 16-H, Li was used._1.04M
n_1.76Al_0.2O _FourIs used in Example 16-I
Li_1.04Mn_1.76Ni_0.2O_FourUsing
Example 16 In 1J, Li_1.04Mn_1.76Co_0.2O
_FourIs used in Example 16-K._1.04Mn
_1.76Mg_0.2O_FourIs used in Example 16-L.
i_1.04Mn_1.76(AlCr)_0.2O_FourFor
In Example 16-M, Li_1.04Mn_1.76(C
rMg)_0.2O_FourIs used in Example 16-N.
_1.04Mn_1.76(CoMg)_0.2O_FourUsing
It was

[0084]

[Table 5]

(Example 16-J-a) As shown in Table 5, Example 16-J-a was the same as Example 16-J except that thermosetting plasticized PVA was used as the positive electrode binder. A battery was made.

Example 16-J-B As shown in Table 5, Example 16-J-B was the same as Example 16-J except that thermosetting plasticized PVA was used as the negative electrode binder. A battery was made.

(Example 16-J-C) As shown in Table 5, in Example 16-J-C, Examples 16-J and C-JC were prepared, except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. A battery was similarly prepared.

(Example 16-N-a) As shown in Table 5, Example 16-N-A was the same as Example 16-N except that thermosetting plasticized PVA was used as the positive electrode binder. A battery was made.

Example 16-N-B As shown in Table 5, Example 16-N-B is the same as Example 16-N except that thermosetting plasticized PVA is used as the negative electrode binder. A battery was manufactured.

(Example 16-N-C) As shown in Table 5, Example 16-N-C and Example 16-N-C, except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. A battery was similarly prepared.

Example 17 As shown in Table 6 below, in Example 17, flake graphite having an average particle size of 10 μm (0.5 times the average particle size of lithium manganate) was used as the carbon material. , The coating amount of lithium manganate is 120 g / m ² ,
Positive electrode coating thickness is 107 μm, positive electrode plate length is 345c
m, the negative electrode active material was PIC, the thickness of the negative electrode coating portion was 79 μm, and the length of the negative electrode plate was 357 cm.

[0092]

[Table 6]

(Example 17-a) As shown in Table 6, in Example 17-a, thermosetting plasticized PV was used as the positive electrode binder.
A battery was produced in the same manner as in Example 17 except that A was used.

(Example 17-b) As shown in Table 6, in Example 17-b, thermosetting plasticized PV was used as the negative electrode binder.
A battery was produced in the same manner as in Example 17 except that A was used.

(Example 17-C) As shown in Table 6, in Example 17-C, a battery was produced in the same manner as in Example 17 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. .

(Examples 17-2 to 17-5) As shown in Table 6, in Examples 17-2 to 17-5, the Li / Mn ratio of lithium manganate was changed, and in Example 17-2. 0.55, 0.58 in Example 17-3, 0.60 in Example 17-4, and 0.
The same procedure as in Example 17 was performed except that the value was set to 61.

(Example 17-3-A) As shown in Table 6, in Example 17-3-A, the same as Example 17-3 except that thermosetting plasticized PVA was used as the positive electrode binder. A battery was made.

(Example 17-3-b) As shown in Table 6, in Example 17-3-b, the same as Example 17-3 except that thermosetting plasticized PVA was used as the negative electrode binder. A battery was made.

Example 17-3-C As shown in Table 6, Example 17-3-C was the same as Example 17-3 except that thermosetting plasticized PVA was used for the positive electrode and negative electrode binders. A battery was similarly prepared.

Comparative Example 1 As shown in Table 6, Comparative Example 1
Then, the coating amount of lithium manganate is 75 g / m ^TwoWhen
Then, the thickness of the positive electrode coating portion is 67 μm, and the length of the positive electrode plate is 453.
cm, the thickness of the negative electrode coating portion is 50 μm, and the length of the negative electrode plate is
The same procedure was performed as in Example 1 except that the length was 465 cm.

Comparative Example 2 As shown in Table 6, Comparative Example 2
Then, the coating amount of lithium manganate was 165 g / m ² , the thickness of the positive electrode coating portion was 146 μm, and the length of the positive electrode plate was 27.
The same procedure as in Example 1 was performed except that the thickness was 8 cm, the thickness of the negative electrode coating portion was 109 μm, and the length of the negative electrode plate was 290 cm.

(Comparative Example 2-a) As shown in Table 6, in Comparative Example 2-a, the compounding ratio of lithium manganate powder, flake graphite and PVDF was set to 86.5: 11: 2.5, and manganese was determined. The amount of lithium oxide applied was 120 g / m ² , the thickness of the positive electrode application portion was 105 μm, and the length of the positive electrode plate was 347 cm.
The thickness of the negative electrode coating part is 79 μm, and the length of the negative electrode plate is 359 cm.
Same as Example 1 except that

(Comparative Example 2-b) As shown in Table 6, in Comparative Example 2-b, the compounding ratio of lithium manganate powder, flake graphite and PVDF was set to 83: 11: 6, and lithium manganate was applied. The coating amount was 120 g / m ² , the thickness of the positive electrode coating portion was 109 μm, the length of the positive electrode plate was 342 cm, the thickness of the negative electrode coating portion was 79 μm, and the length of the negative electrode plate was 354 cm. did.

Comparative Example 3 As shown in Table 6, Comparative Example 3
Then, lithium manganate powder, flake graphite and PVD
The compounding ratio of F is 87: 9: 4, the coating amount of lithium manganate is 120 g / m ² , and the thickness of the positive electrode coating portion is 104 μ.
m, the length of the positive electrode plate was 348 cm, the thickness of the negative electrode coating portion was 79 μm, and the length of the negative electrode plate was 360 cm.

(Comparative Example 4) As shown in Table 6, Comparative Example 4
Then, lithium manganate powder, flake graphite and PVD
The compounding ratio of F was 83: 13: 4, the coating amount of lithium manganate was 120 g / m ² , and the thickness of the positive electrode coating portion was 109 μ.
m, the length of the positive electrode plate was 342 cm, the thickness of the negative electrode coating portion was 79 μm, and the length of the negative electrode plate was 354 cm.

<Test / Evaluation> Next, the following series of tests were performed on each of the batteries of Examples and Comparative Examples produced as described above.

The batteries of Examples and Comparative Examples were charged and then discharged to measure the discharge capacity. The charging conditions were a constant voltage of 4.2 V, a limiting current of 5 A and 3.5 hours. The discharge conditions are
The constant current was 5 A and the final voltage was 2.7 V.

Also, the discharge output of the battery in the charged state was measured under the above conditions. The measurement conditions are 1A, 3A, 6A, reading the voltage at the 5th second at each discharge current, plotting the current value on the horizontal axis on the vertical axis, and the approximate straight line connecting the three points intersects 2.7V. The product of the current value of V and 2.7 V was used as the output.

Further, each of the batteries of Examples and Comparative Examples was repeatedly charged and discharged 100 times under the above-mentioned conditions, and then the output was measured, and the maintenance ratio with respect to the initial output was shown as a percentage. As a matter of course, the higher the maintenance rate, the better the life characteristics.

Further, with respect to the batteries of the examples, subsequently, after repeatedly charging and discharging 100 times under the same conditions except that the ambient temperature of the batteries was set to 60 ° C., the batteries were sufficiently cooled to room temperature (25 ± 1).
The output was measured after returning to ° C), and the maintenance ratio to the initial output was shown as a percentage.

Unless otherwise specified, the charging, discharging, and output measurements were carried out in an atmosphere having an ambient temperature of 25 ± 1 ° C.

After that, the battery thus prepared was subjected to 20 A at room temperature.
It was continuously charged at a constant current and the battery behavior was observed. The battery becomes abnormal due to continuous charging, heat is generated, and the battery surface temperature rises. Along with this, the internal pressure of the battery rises, the cleavage valve 11 is opened, and the gas inside the battery is released to the outside. In order to compare the degree of this gas release, the cell surface temperature immediately after the opening of the cleaving valve was measured. After the gas was released, it was confirmed whether the battery container was deformed. The test results are shown in Tables 7, 8 and 9 below. In Tables 7, 8, and 9, "○" indicates that the battery container was not deformed at all, "△" indicates that the battery container was slightly deformed, and "X" indicates the battery container. Shows a large deformation.

[0113]

[Table 7]

[0114]

[Table 8]

[0115]

[Table 9]

As shown in Table 7, Table 8 and Table 9, the batteries of Examples 1 to 5 have high capacity and high output, and
The battery behavior during continuous charging was also mild. The surface temperature of the battery at this time is 150 ° C to 220 ° C at maximum.
Met. On the other hand, in the battery of Comparative Example 1 in which the amount of lithium manganate applied was less than 80 g / m ² , a battery with high output and high output retention rate was obtained, but the battery behavior during continuous charging was It became severe with deformation and the battery surface temperature exceeded 300 ° C. On the contrary, the coating amount of lithium manganate is 160 g / m.
^With the batteries of Comparative Example 2 exceeding ² , the battery behavior during continuous charging was mild, but the output was lowered, and the results were not suitable as batteries for electric vehicles. Similarly,
The battery of Comparative Example 3 contained 10% by mass of graphite as the positive electrode conductive material.
The result was a decrease in output. On the other hand, in the battery of Comparative Example 4 in which the amount of graphite of the positive electrode conductive material exceeds 12% by mass, a battery with high capacity and high output can be obtained, but the battery behavior during continuous charging is severe with deformation of the battery. The battery surface temperature was 310 ° C.

In the batteries of Examples 6 to 16-N in which graphite and amorphous carbon were mixed as the positive electrode conductive material, high output could be obtained. In the batteries of Examples 6 to 10 in which KB was used as amorphous carbon, the average particle size of graphite was 0.2 to 0.8 times the average particle size of lithium manganate. -The battery of Example 10 was a higher output battery. On the other hand, Example 7 in which the average particle size of graphite is less than 0.2 times the average particle size of lithium manganate.
The battery surface temperature at the time of continuous charging was 210 ° C., which was slightly higher than those of the batteries of Examples 8 to 10.

In the batteries of Examples 11 to 16-N using AB as the amorphous carbon, higher output was obtained,
Moreover, the battery had a high output retention rate after 100 times of charge and discharge.

The Li / Mn ratio of lithium manganate is
Of Example 2-2 to Example 2-5, Example 12 to Example 15, Example 16-2 to Example 16-15, and Example 17-2 to Example 17-5, which are 0.55 or more. The battery resulted in a very high output retention rate. However, Example 2 in which the Li / Mn ratio of lithium manganate exceeds 0.60
In the batteries of Example 5, Example 15, Example 16-5, and Example 17-5, the results were that the capacity decreased. Therefore, Li / M
It can be seen that the n ratio is preferably in the range of 0.55 to 0.60.

Example 15-A using element-substituted lithium manganate (Li _{1 + x} Mn _{2−x− y My} O ₄ ) in which part of manganese atoms of lithium manganate was replaced with another metal element M. In the batteries of Example 15-N and Example 16-A to Example 16-N, both the output and the output retention rate are high,
The battery surface temperature during continuous charging was also low. Among them, the batteries of Examples 16-A to 16-N using PIC as the negative electrode active material have higher output, no deformation of the battery during continuous charging, and lower battery surface temperature. It was However, Example 15-D in which x exceeds 0.1, Example 16-D, and Example 15-G in which y exceeds 0.3,
The batteries of Example 16-G resulted in a slightly lower capacity. Therefore, it is understood that x is preferably in the range of 0 <x ≦ 0.1 and y is preferably in the range of 0 <y ≦ 0.3.

Example 1 using amorphous carbon as the negative electrode active material
The batteries of Example 6, Example 16-2 to Example 16-5, Example 17, and Example 17-2 to Example 17-5 have extremely high output, capacity, and output retention rate, and are also used during continuous charging. There was no deformation of the battery, and the surface temperature of the battery was the lowest. Therefore, these batteries have high capacity, high output, excellent safety, and are well balanced.

In the batteries using thermosetting plasticized PVA as the binder of the positive electrode or the negative electrode, the cells with "a" and "b" added to the end of the numbers have a particularly high temperature as compared with the batteries using PVDF. High output retention rate after repeated charge / discharge cycles.

In the batteries using thermosetting plasticized PVA as the binder of the positive electrode and the negative electrode, "C" is added to the end of the numbers of the examples. The output retention rate after repeating the cycle is even higher.

As described above, in the cylindrical lithium ion battery 20 of this embodiment, the coating amount of lithium manganate is 80 to 160 g / m ² per side of the positive electrode current collector,
PVDF contained in the positive electrode active material mixture in which the amount of the carbon material contained in the positive electrode active material mixture is 10 to 12% by mass
By setting the amount of 3 to 5% by mass, the battery has high capacity and high output, and the behavior is extremely gentle when the battery is exposed to an abnormal state, and the battery is excellent in safety. In this case, if a mixture of graphite and AB or KB is used as the carbon material, a higher output battery can be obtained, and the mass ratio of graphite to AB or KB is 80: 20-9.
If it is set to 0:10, the battery can have a higher output. If the average particle size of graphite is 0.2 to 0.8 times the average particle size of lithium manganate, a battery with higher output can be obtained, and the carbon material can be a mixture of graphite and AB. Thus, a battery having a higher output and a higher output maintenance rate can be obtained. Furthermore, if the Li / Mn ratio of lithium manganate is set to 0.55 to 0.60, the output retention rate can be improved without a decrease in capacity. Further, lithium manganate is represented by Li _{1 + x} Mn _{2−x− y My} O ₄ , where x is 0 <x ≦ 0.1 and y is 0 <y ≦.
0.3, M is Al, Cr, Ni, Co, Mg,
When the metal-substituted lithium manganate, which is at least one element selected from the group, is used, the output retention rate can be improved without lowering the capacity. Furthermore, by using amorphous carbon as the active material of the negative electrode, a battery having high output and high capacity and further excellent safety can be obtained. As described above, the battery having high capacity, high output, and extremely high safety is particularly suitable as a power source for electric vehicles.

In the present embodiment, the lithium ion battery used as the power source for the hybrid electric vehicle is exemplified, but the size and the battery capacity of the battery are not limited, and the battery capacity is about 3 to 10 Ah. On the other hand, it has been confirmed that the present invention exerts a remarkable effect. Further, although a cylindrical battery is exemplified in the present embodiment, the present invention is not limited to the shape of the battery, and can be applied to a prismatic battery and other polygonal batteries. Furthermore,
The shape to which the present invention is applicable may be other than the above-mentioned battery having a structure in which the battery upper lid is closed by caulking in the bottomed cylindrical container (can). An example of such a structure is a battery in which the positive and negative external terminals penetrate the battery lid and the positive and negative external terminals are pressed against each other via the shaft core in the battery container.

Further, in the present embodiment, an example is shown in which the base material is polyimide and the adhesive tape having a hexamethacrylate adhesive applied to one surface thereof is used as the insulating coating. However, for example, the base material is polypropylene. Adhesive tapes made of polyolefins such as polyethylene and polyethylene with acrylic adhesives such as hexamethacrylate and butyl acrylate coated on one or both sides, and tapes made of polyolefins or polyimides without adhesives, etc. can also be preferably used. it can.

Further, in the present embodiment, lithium manganate is used as the positive electrode for the lithium ion battery, graphite or amorphous carbon is used as the negative electrode, and the electrolytic solution has a volume ratio of ethylene carbonate, dimethyl carbonate and diethyl carbonate of 1: 1: 1. A solution obtained by dissolving 1 mol / liter of lithium hexafluorophosphate in a mixed solution was used, but the battery of the present invention is not particularly limited, and a conductive material and a binder (binder) are usually used. Any of the above can be used. In general, lithium manganate can be synthesized by mixing an appropriate lithium salt and manganese oxide and firing the mixture, but by controlling the charging ratio of the lithium salt and manganese oxide, a desired Li / Mn ratio can be obtained. can do.

Further, as the electrode plate active material binder for lithium ion batteries which can be used in other than this embodiment, Teflon (registered trademark), polyethylene, polystyrene, polybutadiene, butyl rubber, nitrile rubber, styrene /
Polymers such as butadiene rubber, polysulfide rubber, nitrocellulose, cyanoethyl cellulose, various latexes, acrylonitrile, vinyl fluoride, vinylidene fluoride, propylene fluoride, chloroprene fluoride, and the like, and mixtures thereof are available. As described above, when the thermosetting plasticized polyvinyl alcohol resin is used, a battery having an extremely high output retention rate can be obtained even after repeating the high temperature charge / discharge cycle.

Furthermore, as the positive electrode active material for a lithium ion battery which can be used in the embodiment other than this embodiment, a lithium manganese ion insertion / desorption material, lithium manganese having a sufficient amount of lithium ions inserted in advance is used. A double oxide is preferable, and a material obtained by doping an element other than manganese or lithium in the crystal may be used.

Further, the negative electrode active material for a lithium ion battery which can be used in the embodiment other than this embodiment is not particularly limited except for the matters described in the above claims. For example, natural graphite, various artificial graphite materials, coke, and carbonaceous materials such as amorphous carbon may be used, and the particle shape thereof is not particularly limited, such as scaly, spherical, fibrous, and lumpy. Absent.

As the non-aqueous electrolytic solution, a common lithium
Electrolyte solution using um salt as electrolyte and dissolving it in organic solvent
Is used. However, the lithium salt or organic solvent used
The medium is not particularly limited. For example, as the electrolyte, Li
C1O_Four, LiAsF₆, LiPF₆, LiBF_Four, L
iB (C₆H₅)_Four, CH_ThreeSO_ThreeLi, CF_ThreeSO _Three
Li or the like or a mixture thereof can be used. Non-hydroelectric
Solvent-dissolving organic solvents include propylene carbonate and ethyl ether.
Ren carbonate, 1,2-dimethoxyethane, 1,2
-Diethoxyethane, γ-butyrolactone, tetrahydr
Rofuran, 1,3-dioxolane, 4-methyl-1,3
-Dioxolane, diethyl ether, sulfolane, methyl
Lesulfolane, acetonitrile, propionitrile, etc.
Or even if you use a mixed solvent of two or more of these
Of course, the mixing ratio is not limited.

[0132]

As described above, according to the present invention,
Since a positive electrode containing a lithium manganese composite oxide having a spinel type crystal structure, a conductive material and a binder, and a negative electrode capable of inserting and extracting lithium ions by charging and discharging are used,
High capacity and high output can be achieved, and the coating amount of lithium manganese composite oxide is 80 g / m ^{2 to} 160 g /
Since m ² is used, the mass of the conductive material is set to 10% by mass to 12% by mass, and the mass of the binder is set to 3% by mass to 5% by mass, gas release from the internal pressure release mechanism is performed extremely gently. Therefore, while having high capacity and high output,
It is possible to obtain the effect that it is possible to realize an extremely safe non-aqueous electrolyte secondary battery.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cylindrical lithium-ion battery of an embodiment to which the present invention can be applied.

[Explanation of symbols]

1 Shaft Core 6 Winding Group (Electrode Winding Group) 7 Battery Container 11 Cleavage Valve (Internal Pressure Release Mechanism) 20 Cylindrical Lithium Ion Battery (Non-Aqueous Electrolyte Secondary Battery) W1 Positive Electrode Current Collector W2 Positive Electrode Active Material Mixture Layer W3 Negative electrode current collector W4 Negative electrode active material mixture layer W5 Separator

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kensuke Hironaka             2-8-7 Nihonbashihonmachi, Chuo-ku, Tokyo             Inside Shin-Kobe Electric Machinery Co., Ltd. F term (reference) 5H029 AJ02 AJ03 AJ12 AK03 AL07                       AL08 AM03 AM05 AM07 BJ02                       CJ22 DJ07 DJ08 DJ17 EJ04                       EJ12 HJ00 HJ01 HJ02 HJ05                 5H050 AA02 AA08 AA15 BA17 CA09                       CB08 CB09 DA04 DA10 DA11                       EA09 EA10 EA23 FA19 GA22                       HA00 HA01 HA02 HA05

Claims (11)

[Claims] 1. A positive electrode in which a positive electrode active material mixture containing a lithium manganese oxide having a spinel type crystal structure, a conductive material, and a binder is applied on both sides of a strip-shaped current collector in an approximately equal amount, and by charging and discharging. A negative electrode mixture consisting of a carbonaceous material capable of absorbing and desorbing lithium ions, a binder, and a conductive material selectively applied on both sides of a strip-shaped current collector in an approximately equal amount was wound with a separator. In a non-aqueous electrolyte secondary battery in which an electrode winding group is housed in a battery container having an internal pressure release mechanism that releases internal pressure at a predetermined pressure, the amount of the lithium manganese oxide coated on one side of the current collector is applied. Is 80 g / m
^{2 to} 160 g / m ² , and the mass of the conductive material is 10 mass% to 12 mass% of the positive electrode active material mixture,
Moreover, the mass of the binder is 3 mass% of the positive electrode active material mixture.
To 5 mass% of the non-aqueous electrolyte secondary battery. 2. The non-aqueous electrolyte secondary battery according to claim 1, wherein the conductive material is a mixture of graphite and amorphous carbon. 3. The non-aqueous electrolyte secondary battery according to claim 2, wherein the mass ratio of graphite and amorphous carbon in the mixture is 80:20 to 90:10. 4. The average particle diameter of the graphite is 0.2 to 0.8 times the average particle diameter of the lithium manganese oxide. Non-aqueous electrolyte secondary battery. 5. The non-aqueous electrolyte secondary battery according to claim 2, wherein the amorphous carbon is acetylene black. 6. Li / manganese compound oxide Li /
The non-aqueous electrolyte secondary battery according to any one of claims 1 to 5, wherein the Mn ratio is 0.55 to 0.60. 7. The lithium manganese composite oxide is Li
_{1 + x Mn 2-x- y} M y O 4 (x is 0 <x ≦ 0.1,
y is 0 <y ≦ 0.3, M is A1, Cr, Ni, Co, M
The non-aqueous electrolyte secondary battery according to any one of claims 1 to 5, wherein the non-aqueous electrolyte secondary battery is represented by at least one element selected from the group consisting of g). 8. The non-aqueous electrolyte secondary battery according to claim 1, wherein the active material of the negative electrode is amorphous carbon. 9. The non-woven fabric according to claim 1, wherein the binder of the positive electrode is a thermosetting plasticized polyvinyl alcohol resin modified mainly with polyvinyl alcohol. Water electrolyte secondary battery. 10. The binder according to claim 1, wherein the binder of the negative electrode is a thermosetting plasticized polyvinyl alcohol resin mainly composed of polyvinyl alcohol and modified. Water electrolyte secondary battery. 11. The binder according to claim 1, wherein the binder of the positive electrode and the negative electrode is a thermosetting plasticized polyvinyl alcohol resin modified mainly with polyvinyl alcohol. Non-aqueous electrolyte secondary battery.