JP2003068365A - Secondary battery of nonaqueous electrolytic solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery of nonaqueous electrolytic solution, which is longer in service life and can restrain a drop in rate to keep capacity and output, caused by charging/discharging cycles. SOLUTION: A lithium manganate powder, a graphitic powder, AB and PVDF are mixed at a predetermined rate, to which NMP of a disperse solvent is added, and then the resultant matter is kneaded to produce slurry. The slurry was coated 20 μm thick with coating amount of P1 (gm<2> ) almost evenly on both faces of aluminum foil. Supposing that the total surface area of the lithium manganate powder, the graphitic powder and the AB contained in an admixture of 100 g for a positive electrode is S1 (m<2> ), and that mass of the PVDF contained in the admixture of 100 g for the positive electrode is B1 (g), the ratio of B1 /S1 was set to meet an expression of 1.00.P1 <=(B1 /S1 )×10000<=2.00.P1 . Peeling and removal of the admixture for the positive electrode adhered by coating are prevented and a reaction area of the electrode with the nonaqueous electrolytic solution can be secured.

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 positive electrode current collector coated with a positive electrode mixture material containing a lithium transition metal complex oxide, a conductive material using carbon and a binder. The present invention relates to a non-aqueous electrolyte secondary battery in which an electrode group having the positive electrode, the negative electrode, and a separator is soaked in a non-aqueous electrolyte and housed in a battery container.

[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 a wound structure 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 18650 type and has a diameter of 18 mm and a height of 65 mm, and is widely used as a small-sized 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 the 18650 type lithium ion secondary battery, and the battery capacity is about 1.3 Ah to 1.8 Ah, and the output is about 1.
It is about 0W.

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 for an electric vehicle is required to have characteristics such as high capacity and high output and high energy such as reduction of internal resistance of the battery, and a lithium ion battery is a battery which meets this requirement. Attention has been paid. In order to popularize electric vehicles, it is essential to reduce the price of batteries. For that purpose, low-cost battery materials are required. For example, in the case of positive electrode active materials, resource-rich manganese oxides are In particular, attention has been paid to improvements aimed at improving the performance of batteries.

[0006]

However, in order to use the non-aqueous electrolyte secondary battery as a power source for an electric vehicle, it goes without saying that not only high capacity but also high output that influences acceleration performance and the like are required. Therefore, it is strongly demanded that the battery have a long life so that it can be used for a long period of time. The term “longer life” as used herein means that not only the battery capacity but also a reduction in the output maintenance rate is suppressed, and the electric energy supply capacity required to drive the electric vehicle is satisfied over a long period of use. .

In view of the above problems, it is an object of the present invention to provide a non-aqueous electrolyte secondary battery having a long life and capable of suppressing a decrease in capacity and output retention rate due to charge / discharge cycles.

[0008]

In order to solve the above-mentioned problems, the first aspect of the present invention is to collect a positive electrode mixture containing a lithium-transition metal composite oxide, a carbon-based conductive material and a binder as a positive electrode current collector. In a non-aqueous electrolyte secondary battery in which a positive electrode coated on the body, a negative electrode, and a separator, the non-aqueous electrolytic solution is infiltrated with a non-aqueous electrolytic solution and housed in a battery container, a unit mass of the positive electrode mixture material ( The mass of the binder contained per g) is B ₁ (g), and the total surface area of the lithium transition metal composite oxide and the conductive material contained per unit mass of the positive electrode mixture is S ₁ (m ^2). ) And the coating amount of the positive electrode mixture per unit surface area (m ² ) of the positive electrode current collector is P ₁ (g / m ² ), the total surface area S
The mass _{B 1} ratio _B 1 / _{S 1} is represented by the following formula for ₁ (1)
Meet

[0009]

[Equation 7]

When the expansion and contraction of the electrode group is repeated with the occluding / releasing of lithium ions due to the charging / discharging cycle, the positive electrode mixed material is peeled / dropped off, resulting in a decrease in capacity and output. It can be dealt with by increasing. On the contrary, when the amount of the binder is increased, the amounts of the lithium transition metal complex oxide and the conductive material contained per unit mass of the positive electrode mixture material are relatively reduced, which leads to a decrease in the initial output. Since the surface area of the material and the conductive material is small and the reaction area of the electrode is small, the reaction with the non-aqueous electrolyte is not promoted and the initial capacity and output are reduced. Formula (1) of the present embodiment shows that the mass B ₁ of the binder also needs to be increased in order to increase the total surface area S ₁ . Further, the ratio B ₁ / S ₁ is 1.00 · P ₁
When it is less than / 10 000, the amount of the binder is small, so that the positive electrode mixture material is peeled off and dropped, so that the capacity and output retention rate is reduced, and conversely, 2.00 P ₁ / 10,000.
If it exceeds, the amount of the binder is increased, and the initial capacity and output are reduced. In the present embodiment, the ratio B ₁ / S ₁ is set within the range of the formula (1) with respect to the coating amount P ₁ , whereby peeling and dropping of the coated positive electrode mixture material is prevented, and Since it is possible to secure the electrode reaction area, it is possible to suppress a decrease in capacity and output retention rate due to charge / discharge cycles, and it is possible to realize a long-life non-aqueous electrolyte secondary battery. Further, by using the thermosetting plasticized polyvinyl alcohol resin as the binder, it is possible to realize a non-aqueous electrolyte secondary battery having a longer life.

A second aspect of the present invention is a charge / discharge method.
Carbon materials that can store and release um ions, binders and selection
Alternatively, the negative electrode mixture containing the conductive material was applied to the negative electrode current collector.
A non-aqueous electrode group having a negative electrode, a positive electrode, and a separator is used.
A non-aqueous electrolyte solution that was soaked in the electrolyte solution and stored in the battery container
In the secondary battery, the unit mass (g) of the negative electrode mixture material
The mass of the binder contained in B_Two(G),
The carbon contained per unit mass of the negative electrode mixture material
The total surface area of the material and conductive material is S_Two(M^Two) And then the negative
One side unit area (m)^Two) Per negative electrode mixture
The applied amount of material is P _Two(G / m^Two) And then the total
Surface area S_TwoTo the mass B_TwoRatio B of _Two/ S_TwoIs the following
Formula (3) is satisfied.

[0012]

[Equation 8]

In this embodiment, the ratio B ₂
The same effect as the first aspect described above is obtained for the negative electrode in that / S ₂ is within the range of the formula (3) with respect to the coating amount P ₂ .

A third aspect of the present invention is lithium
Transition metal complex oxide, conductive material and binder using carbon
Charge and discharge the positive electrode with the positive electrode mixture material coated on the positive electrode current collector.
Carbon material that can store and release lithium ions by
And a negative electrode mixture containing a conductive material, and a negative electrode current collector.
A negative electrode coated on the
Non-aqueous electrolyte that is immersed in a water electrolyte and stored in a battery container
In the secondary battery, the unit mass (g) of the positive electrode mixture is
B is the mass of the binder contained in₁(G)
, And the positive electrode mixture is contained per unit mass.
The total surface area of the lithium transition metal complex oxide and the conductive material is S
₁(M2), one side unit area of the positive electrode current collector
(M^Two) Is the coating amount of the positive electrode mixed material per P₁(G /
m^Two) And the unit mass (g) of the negative electrode mixture material.
B is the mass of the binder contained in _Two(G)
The content contained per unit mass of the negative electrode mixture material
The total surface area of carbon material and conductive material is S_Two(M^Two) And before
One-sided unit area of negative electrode current collector (m^Two) Per negative electrode
The coating amount of the mixed material is P_Two(G / m^Two) When the above
Total surface area S₁To the mass B₁Ratio B of₁/ S₁But
The following formula (5-1) is satisfied, and the total surface area S is_TwoTo
To the mass B_TwoRatio B of_Two/ S_TwoIs the following formula (5-2)
Meet

[0015]

[Equation 9]

In this mode, the positive electrode and the negative electrode simultaneously exhibit the effects of the first mode and the second mode described above, so that it is possible to further suppress the decrease in the capacity and the output maintenance rate due to the charge / discharge cycle. Further, it is possible to realize a non-aqueous electrolyte secondary battery having a longer life.

[0017]

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

<First Embodiment> (Production of Positive Electrode) Lithium manganate (LiMn ₂ O) as a lithium transition metal composite oxide having a predetermined specific surface area.
₄ ) Powder or lithium cobalt oxide (LiCoO ₂ ) (Nippon Kagaku Kogyo KK, trade name Cell Seed), graphite powder having a specific surface area as a conductive material (Nippon Graphite Kogyo KK, trade name J-) SP) and acetylene black (hereinafter abbreviated as AB) (manufactured by Denki Kagaku Kogyo KK,
Trade name Denka Black) and polyvinylidene fluoride (PVDF) as a binder (binder) or NMP solution of thermosetting plasticized polyvinyl alcohol resin were mixed at a predetermined ratio to prepare a positive electrode mixture. If necessary, N-methyl-2-pyrrolidone (NMP) as a dispersion solvent may be added.
Was added and kneaded on both surfaces of an aluminum foil (positive electrode current collector) having a thickness of 20 μm so that the applied amount P ₁ (g / m ² ) was applied substantially evenly. 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.

The total surface area of the surface area of the lithium manganate powder or lithium cobalt oxide and the surface area of the graphite powder and AB contained in 100 g of the positive electrode mixture containing the respective materials was set to S ₁ (m ² ), and the positive electrode mixture was obtained. When the mass of the binder contained in 100 g of the material is B ₁ (g), the ratio B ₁
/ S ₁ is set to satisfy the following formula (1). The specific surface area of each material can be measured by the nitrogen adsorption method (BET method).

[0020]

[Equation 10]

After that, it is dried, pressed and cut to a width of 82 m.
A positive electrode having m, a predetermined length, and a predetermined thickness of the positive electrode mixture applying portion was obtained. The bulk density of the positive electrode mixed material 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.

(Production of Negative Electrode) Amorphous carbon powder having a specific surface area (produced by Kureha Chemical Industry Co., Ltd., trade name: CARBOTRON), graphite powder, massive graphite (produced by Hitachi Chemical Co., Ltd.)
(Hereinafter, abbreviated as MAG), mesophase spheroidal graphite (Kawasaki Steel Co., Ltd., trade name KMFC) (hereinafter KM
It is abbreviated as FC. ) Any of the negative electrode active materials, vapor-grown carbon fibers of conductive material (Showa Denko KK, trade name VGC
F) (hereinafter abbreviated as VGCF) or PVDF of AB and binder, or NMP solution of thermosetting plasticized polyvinyl alcohol resin was mixed at a predetermined ratio to prepare a negative electrode mixture material. If necessary, NMP as a dispersion solvent was added, and the kneaded slurry was applied to both sides of a rolled copper foil (negative electrode current collector) having a thickness of 10 μm so that the coating amount was P ₂ (g / m ² ). It was applied evenly. At this time, an uncoated portion having a width of 30 mm was left on one side edge in the longitudinal direction of the negative electrode.

The total surface area of the surface area of the carbonaceous material and the surface area of VGCF or AB contained in 100 g of the negative electrode mixture material 100 in which the respective materials are mixed is defined as S ₂ (m2).
The mass of PVDF contained in 0 g was defined as B ₂ (g). The specific surface area of each material is the nitrogen adsorption method (BET method).
Can be measured by

Thereafter, it is dried, pressed and cut to have a width of 86 m.
A negative electrode having m, a predetermined length, and a predetermined thickness of the mixed material application portion was obtained. The negative electrode was compressed so that the porosity of the negative electrode mixture layer was about 35%. A negative electrode using a thermosetting plasticized polyvinyl alcohol resin as a binder is then subjected to 15
Vacuum drying and heat treatment were performed at 0 ° C for 16 hours. 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. 50 mm between adjacent negative electrode lead pieces
The gap was set and the width of the negative electrode lead piece was set to 5 mm.

(Production of Thermosetting Plasticized Polyvinyl Alcohol Resin) The thermosetting plasticized polyvinyl alcohol resin comprises a first resin component made of a thermosetting polyvinyl alcohol resin and a second resin component made of an acrylic resin plasticizer. The resin component was mixed and dissolved in an appropriate solvent (N-methyl-2-pyrrolidone, hereinafter referred to as NMP) in a suitable solvent. The thermosetting polyvinyl alcohol resin, which is the first resin component, has an average degree of polymerization of about 2000.
It can be obtained by reacting a polyvinyl alcohol resin of a certain degree with a cyclic acid anhydride such as succinic anhydride in an organic solvent such as NMP in a substantially anhydrous state in the presence of a catalyst such as triethylamine. 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 as the second resin component, a reaction product of a lauryl acrylate / acrylic acid copolymer and a bifunctional epoxy resin is suitable.

Hereinafter, 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.

(Production of Battery) As shown in FIG. 1, the positive electrode and the negative electrode produced as described above 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 these electrodes. A hollow cylindrical shaft core 1 made of polypropylene was used as the center of winding. At this time, the positive electrode lead piece 2 and the negative electrode lead piece 3 were positioned on opposite end surfaces of the winding group (electrode group) 6, respectively. Further, the lengths of the positive electrode, the negative electrode, and the separator were adjusted so that the winding group 6 had a diameter of 38 ± 0.1 mm.

The positive electrode lead piece 2 is deformed, and all of them are
After gathering and contacting in the vicinity of the flange portion that integrally projects from the periphery of the positive electrode current collecting ring 4 that is almost on the extension of the axis 1 of the winding group 6, the positive electrode lead piece 2 and the periphery of the flange portion are superposed. The positive electrode lead piece 2 was connected to the peripheral surface of the flange by sonic welding. On the other hand, the operation of connecting the negative electrode current collecting ring 5 and the negative electrode lead piece 3 was performed in the same manner as the operation of connecting the positive electrode current collecting ring 4 and the positive electrode lead piece 2.

After that, an insulating coating was applied to the entire circumference of the flange portion of the positive electrode current collecting ring 4. 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 battery container 7 has an outer diameter of 40 mm and an inner diameter of 39 mm.

A negative electrode lead plate 8 for electrical conduction is welded to the negative electrode current collecting ring 5 in advance. After the winding group 6 is inserted into the battery container 7, the bottom portion of the battery container 7 and the negative electrode lead plate 8 are joined together. Welded.

On the other hand, the positive electrode current collector ring 4 is previously welded with a positive electrode lead 9 formed by stacking a plurality of aluminum ribbons, and the other end of the positive electrode lead 9 seals the battery container 7. Welded to the underside of the battery lid for. The battery lid is provided with a cleaving valve 11 as an internal pressure releasing mechanism that cleaves in response to 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 includes a lid case 12 and a lid cap 13.
It is composed of a valve retainer 14 for keeping airtightness and a cleaving valve (internal gas discharge valve) 11, which are laminated and assembled by caulking the peripheral edge of the lid case 12.

A predetermined amount of the non-aqueous electrolyte is injected into the battery container 7, and then the battery container 7 is covered with the battery cover so that the positive electrode lead 9 is folded, and the EPDM resin gasket 1
The cylindrical lithium-ion battery 20 was completed by caulking and sealing through 0.

For the non-aqueous electrolyte, lithium hexafluorophosphate (L) was added to a mixed solution of ethylene carbonate, dimethyl carbonate and diethyl carbonate at a volume ratio of 1: 1: 1.
A solution obtained by dissolving 1 mol / l of iPF6) was used.
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.

In the present embodiment, the total surface area S _{1 of the} surface area of the lithium manganate powder or lithium cobalt oxide and the surface area of the graphite powder and AB contained in the positive electrode mixture material.
By setting the ratio B ₁ / S ₁ of the mass B ₁ of the binder to that within the range of the above formula (1), the manufactured cylindrical lithium ion battery 20 has
It can be prevented from falling off and the electrode reaction area with the non-aqueous electrolyte can be secured. The cylindrical lithium-ion battery 20 is occluded / desorbed by lithium ions during charge / discharge cycles.
When the expansion and contraction of the winding group 6 is repeated over time, the positive electrode mixed material peels and falls off, and the capacity and output decrease. Therefore, it is necessary to increase the amount of binder to prevent the positive electrode mixed material from peeling off and falling off. is there. However, when the amount of the binder is increased, the amounts of the lithium manganate powder or lithium cobalt oxide, the graphite powder and AB contained per unit mass in the coating amount P ₁ of the positive electrode mixture relatively decrease, and It causes a decrease in output. Further, since the surface area S _{1 of} lithium manganate powder or lithium cobalt oxide, graphite powder and AB is small and the electrode reaction area is small, the reaction with the non-aqueous electrolyte is not promoted and the initial capacity and output are reduced. . By setting the ratio B ₁ / S ₁ within the range of the above formula (1), it becomes possible to prevent the peeling and dropping of the positive electrode mixture material by the contained binder while securing a sufficient electrode reaction area. . Therefore, the cylindrical lithium-ion battery 20 manufactured in this manner is a battery having a long life, which can suppress a decrease in capacity and output retention rate. When the ratio B ₁ / S ₁ is less than the range of the above formula (1), the amount of the binder is small, so that the positive electrode mixed material may be peeled or dropped off, which is not preferable. When it exceeds the above range, the amount of the binder increases and the electrode reaction area decreases, which is not preferable. In this case, if the ratio B ₁ / S ₁ is set to satisfy the following formula (2), both capacity and output can be maintained in a well-balanced manner, and a long-life cylindrical lithium ion battery 20 can be obtained.

[0039]

[Equation 11]

<Second Embodiment> Next, a second embodiment in which the non-aqueous electrolyte secondary battery of the present invention is applied to a cylindrical lithium ion battery as a power source for a hybrid electric vehicle will be described. In this embodiment and the following embodiments, the same members as those in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and only different portions will be described.

In the present embodiment, the positive electrode has a lithium transition metal composite oxide lithium manganate (LiMn ₂ O ₄ ) powder or lithium cobalt oxide (LiCoO ₂ ) having a predetermined specific surface area (Nippon Kagaku Kogyo Co., Ltd.). Manufactured by Nippon Graphite Industry Co., Ltd., trade name J-SP, and AB by a conductive material having a predetermined specific surface area.
A positive electrode mixture material obtained by mixing Denka Black (trade name, manufactured by Denki Kagaku Kogyo Co., Ltd.) and a binder in a predetermined ratio was used. For the negative electrode, an amorphous carbon powder having a predetermined specific surface area (Kureha Chemical Industry Co., Ltd., trade name: CARBOTRON), graphite powder, a carbon material of MAG or KMFC, and a conductive material having a predetermined specific surface area. VGCF or AB as a binder and PVDF or a thermosetting plasticized polyvinyl alcohol resin as a binder (binder) at a predetermined ratio, and the ratio B of the mass B ₂ of the binder to the total surface area S ₂ is used. ₂ / S ₂ is set to satisfy the following formula (3).

[0042]

[Equation 12]

In this embodiment, the ratio B_Two/ S_TwoThe above formula
By making it within the range of (3), the produced cylindrical lithium
The um-ion battery 20 is designed to remove the coated negative electrode mixture material.
Prevents falling off and secures electrode reaction area with non-aqueous electrolyte
be able to. The cylindrical lithium ion battery 20 is described above.
In the same way as the positive electrode
Prevents peeling / falling of composite materials and suppresses reduction in capacity and output
There is a need. However, if the amount of binder is increased, the negative electrode mixture
Coating material amount P_TwoCarbon contained per unit mass in
The amount of wood, VGCF or AB decreases relatively,
It causes a decrease in power. Also, a table of carbon material, VGCF or AB
Area S_TwoBecomes smaller and the electrode reaction area becomes smaller,
The reaction with the non-aqueous electrolyte is not promoted and the initial capacity and output
descend. Ratio B_Two/ S_TwoBe within the range of the above formula (3)
By doing so, it was contained while ensuring a sufficient electrode reaction area.
Use PVDF to prevent the negative electrode mixture from peeling off
Is possible. Therefore, the cylindrical lithi
The um-ion battery 20 suppresses the decrease in the capacity and the maintenance rate of the output.
It is a long-life battery that can be controlled. Ratio B_Two/ S _Two
Is less than the range of the above formula (3), the amount of binder
It is preferable because the negative electrode mixed material may peel off or fall off.
If it is not good and conversely exceeds the range of the above formula (3),
Causes the amount of binder to increase and the electrode reaction area to decrease.
It is not preferable because In this case, the ratio B_Two/ S_Two
If the following equation (4) is satisfied, both capacity and output are
Well-balanced and long-life cylindrical lithium ion
The battery 20 can be obtained.

[0044]

[Equation 13]

<Third Embodiment> Next, a third embodiment in which the non-aqueous electrolyte secondary battery of the present invention is applied to a cylindrical lithium ion battery as a power source for a hybrid electric vehicle will be described. In the present embodiment, the ratio B ₁ of the mass B ₁ of the binder to the total surface area S ₁ of the positive electrode mixture material
In addition to keeping / S ₁ within the same range as in the first embodiment,
The ratio B ₂ / S ₂ of the mass B ₂ of the binder to the total surface area S ₂ of the negative electrode mixture is set within the same range as in the second embodiment. That is, the ratio B ₁ / S ₁ satisfies the following formula (5-1), and the ratio B ₂ / S ₂ is the following formula (5-).
2) be satisfied.

[0046]

[Equation 14]

By satisfying both expressions, the above-described first embodiment
Since the state and the operation of the second embodiment are simultaneously achieved, the cylindrical shape
The lithium-ion battery 20 has a capacity according to charge / discharge cycles.
It is possible to further suppress the deterioration of the output maintenance ratio and
The battery can have a long life. In this case,
Ratio B₁/ S₁Satisfies the following formula (6-1), and the ratio B _Two
/ S_TwoBy satisfying the following formula (6-2),
A long-life cylindrical refill that can maintain both quantity and output in good balance.
It is possible to obtain a lithium ion 20 battery.

[0048]

[Equation 15]

[0049]

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

(Example 1) As shown in Table 1 below, Example 1 is according to the second embodiment, and the positive electrode is 100 g of the positive electrode mixture material.
^3. 89 g of lithium manganate (MN1) having a specific surface area of 0.98 g / m ² and graphite powder having a specific surface area of 9 m ² / g.
95 g, AB 0.75 g with specific surface area 40 m ² / g, PV
A positive electrode mixture containing DF5.3g was applied to an aluminum foil with a coating amount of P ₁ = 345g / m ² , and the negative electrode was 100 g of the negative electrode mixture and was amorphous with a specific surface area of 3.5g / m ² . Quality carbon (A1) 88g, specific surface area 14m ² / g VGCF
A negative electrode mixture containing 3 g of PVDF and 9 g of PVDF was applied to a copper foil at an applied amount of P ₂ = 90 g / m ² (in the following examples and comparative examples, the readings in Tables 1 to 3 are the same). The calculated value on the positive electrode side (ratio B ₁ / S ₁ × 10000) is the applied amount P ₁
In divided by a number and coefficient values of _{P 1,} when the calculated value of the negative electrode side of the value obtained by dividing by the coating weight _{P 2} (the ratio _{B 2} / _S 2 × 10000) was coefficient values of _{P 2,} the _{P 1} The coefficient value was 0.95 and the coefficient value of P ₂ was 2.86. Therefore, the coefficient value of P ₁ is expressed by the equation (1), the equation (2), the equation (5-1), and the equation (6-
1) means the value of the coefficient by which P ₁ is multiplied, and the coefficient value of P ₂ is equation (3), equation (4), equation (5-2), equation (6-2)
Means the value of the coefficient to be multiplied by P ₂ . The specific surface area of each material used for the conductive material is graphite powder: 9 m ² /
g, AB: 40 m ² / g, VGCF: 14 m ² / g, and the specific surface area of each material used for the negative electrode carbon material is graphite powder: 4.5 m ² / g, MAG: 3 m ² / g, KMFC:
It was 1.5 m ² / g (the same applies to Examples and Comparative Examples described below).

In Tables 1 to 3, the blending amount of each material is shown by the number of grams (g) contained in 100 g of the positive electrode or negative electrode mixed material. Further, MN1 is lithium manganate having a transition metal of manganese and a specific surface area of 0.98 m ² / g, MN2 is lithium manganate having a specific surface area of 0.4 m ² / g, and MN3 is 0.7 m ² of specific surface area. / G of lithium manganate, and CO represents a transition metal of cobalt and a specific surface area of 0.55 m ² / g of lithium cobalt oxide. Furthermore, A1 has a specific surface area of 3.5 m ² /
g of amorphous carbon, and A2 represents amorphous carbon having a specific surface area of 6 m ² / g.

(Examples 2 to 4) As shown in Table 1 below, in Examples 2 to 4, the coefficient value of P ₁ is set to 1.00 in Example 2 according to the _first embodiment. 1.6 in example 3
0, in Example 4, it was set to 1.99, and the coefficient value of P ₂ was set to 3.91 in Examples 2 to 4.

(Example 3-A) As shown in Table 1 below, Example 3-A was prepared in the same manner as in Example 3 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode. It is a battery.

Example 5 As shown in Table 1 below, in Example 5, the coefficient value of P ₁ was set to 0.96 and the coefficient value of P ₂ was set to 3.16 according to the second embodiment.

(Example 5-A) As shown in Table 1 below, Example 5-A was prepared in the same manner as in Example 5 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the negative electrode. It is a battery.

(Example 6 to Example 8) As shown in Table 1 below, in Example 6 to Example 8, the coefficient value of P ₁ was set to 1.00 in Example 6 according to the _first embodiment. 1.6 in Example 7
In Example 9 and Example 8, it was set to 2.00, and the coefficient value of P ₂ was set to 3.91 in Examples 6 to 8.

(Example 7-A) As shown in Table 1 below, Example 7-A was prepared in the same manner as in Example 7 except that a thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode. It is a battery.

(Examples 9 to 11) As shown in Table 1 below, Examples 9 to 11 are P-type according to the second embodiment.
The coefficient value of ₁ is 2.11 in all of the ninth to eleventh embodiments, and the coefficient value of P ₂ is 2.10 in the ninth embodiment and the first embodiment.
0 was set to 2.86, and Example 11 was set to 3.80.

(Example 9-A) As shown in Table 1 below, Example 9-A was prepared in the same manner as in Example 9 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the negative electrode. It is a battery.

(Example 10-A) As shown in Table 1 below,
Example 10-A is a battery produced in the same manner as in Example 10 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the negative electrode.

[0061]

[Table 1]

Example 12 As shown in Table 1, in Example 12, according to the first embodiment, the coefficient value of P ₁ was 1.60 and the coefficient value of P ₂ was 2.00.

(Example 12-A) As shown in Table 1, in Example 12-A, a battery prepared in the same manner as in Example 12 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode. Is.

Examples 13 to 15 As shown in Table 1, Examples 13 to 15 are in accordance with the second embodiment.
The coefficient value of P ₁ is set to 2.15 in each of Examples 13 to 15.
The coefficient value of P ₂ is 2.10 in Example 13, 3.16 in Example 14, and 3.80 in Example 15.

(Examples 16 to 17) As shown in Table 1, Examples 16 to 17 are in accordance with the first embodiment.
The coefficient value of P ₁ is 1.69 for both Example 16 and Example 17.
The coefficient value of P ₂ was set to 2.06 in Example 16 and 2.01 in Example 17.

(Example 16-A) As shown in Table 1, in Example 16-A, a battery produced in the same manner as in Example 16 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode. Is.

(Example 17-A) As shown in Table 1, in Example 17-A, a battery prepared in the same manner as in Example 17 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode. Is.

(Examples 18 to 20) As shown in Table 1, Examples 18 to 20 are in accordance with the second embodiment.
The coefficient value of P ₁ is set to 2.15 in each of Examples 18 to 20.
The coefficient value of P ₂ is 2.10 in Example 18, 2.94 in Example 19 and 3.80 in Example 20.

(Example 21) As shown in Table 2 below, in Example 21, the coefficient value of P ₁ was 1.69 according to the first embodiment.
And the coefficient value of P ₂ was set to 3.91.

(Example 21-A) As shown in Table 2, in Example 21-A, a battery prepared in the same manner as in Example 21 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode. Is.

[0071]

[Table 2]

(Examples 22 to 30) As shown in Table 2, Examples 22 to 30 are in accordance with the third embodiment.
The coefficient value of P ₁ is 1.00 in Example 22,
1.60, Example 24 is 1.99, Example 25 is 1.00, Example 26 is 1.69, Example 27 is 2.00, Example 28 is 1.00, and Example 29 is 1. .69, and in Example 30 it was set to 2.00. The coefficient value of P ₂ is 2.10 in Example 22 and 2.8 in Example 23.
6, 3.80 in Example 24, 2.1 in Example 25
0, 3.26 in Example 26, 3.8 in Example 27.
0, Example 28 2.10, Example 29 2.9.
4. In Example 30, it was set to 3.80.

(Example 22-A) As shown in Table 2, Example 22-A is the same as Example 22-A except that thermosetting plasticized polyvinyl alcohol was used as the binder for the positive electrode and the negative electrode.
It is a battery manufactured in the same manner as.

(Example 23-A) As shown in Table 2, in Example 23-A, except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode and the negative electrode.
It is a battery manufactured in the same manner as.

(Example 26-A) As shown in Table 2, in Example 26-A, except that thermosetting plasticized polyvinyl alcohol was used as the binder for the positive electrode and the negative electrode.
It is a battery manufactured in the same manner as.

(Example 28-A) As shown in Table 2, in Example 28-A, except that thermosetting plasticized polyvinyl alcohol was used as the binder for the positive electrode and the negative electrode.
It is a battery manufactured in the same manner as.

(Example 29-A) As shown in Table 2, in Example 29-A, except that a thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode and the negative electrode.
It is a battery manufactured in the same manner as.

(Example 31) As shown in Table 2, in Example 30, according to the second embodiment, the coefficient value of P ₁ was set to 0.92 and the coefficient value of P ₂ was set to 2.98.

Example 31-A As shown in Table 2, in Example 31-A, a battery prepared in the same manner as in Example 31 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the negative electrode. Is.

(Examples 32 to 34) As shown in Table 2, Examples 32 to 34 are in accordance with the third embodiment.
The coefficient value of P ₁ is 1.00 in Example 32 and 33 in Example 33.
Was 1.48 and in Example 34, it was 2.00. The coefficient value of P ₂ was 2.10 in Example 32, 2.98 in Example 33, and 3.80 in Example 34.

(Example 32-A) As shown in Table 2, in Example 32-A, except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode and the negative electrode.
It is a battery manufactured in the same manner as.

(Example 33-A) As shown in Table 2, in Example 33-A, except that a thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode and the negative electrode,
It is a battery manufactured in the same manner as.

(Example 34-A) As shown in Table 2, in Example 34-A, except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode and the negative electrode, Example 34-A was used.
It is a battery manufactured in the same manner as.

Example 35 As shown in Table 2, in Example 35, according to the second embodiment, the coefficient value of P ₁ was 2.16 and the coefficient value of P ₂ was 2.98.

(Example 35-A) As shown in Table 2, in Example 35-A, a battery prepared in the same manner as in Example 35 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the negative electrode. Is.

Example 36 As shown in Table 2, in Example 36, the coefficient value of P ₁ was set to 1.61 and the coefficient value of P ₂ was set to 2.01 according to the first embodiment.

(Examples 37 to 39) As shown in Table 2, Examples 37 to 39 are in accordance with the third embodiment.
The coefficient value of P ₁ is 1.00 in Example 37 and 38 in Example.
Was 1.61 and that of Example 39 was 2.00. The coefficient value of P ₂ was 2.12 in Example 37, 2.90 in Example 38, and 3.80 in Example 39.

(Example 38-A) As shown in Table 2, in Example 38-A, a battery prepared in the same manner as in Example 38 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the negative electrode. Is.

(Example 39-A) As shown in Table 2, in Example 39-A, except that thermosetting plasticized polyvinyl alcohol was used as the binder for the positive electrode and the negative electrode, Example 39-A was used.
It is a battery manufactured in the same manner as.

(Example 40) As shown in Table 2, in Example 40, the coefficient value of P ₁ was set to 1.61 and the coefficient value of P ₂ was set to 3.88 according to the first embodiment.

(Example 40-A) As shown in Table 2, in Example 40-A, a battery prepared in the same manner as in Example 40 except that thermosetting plasticized polyvinyl alcohol was used as the binder of the positive electrode. Is.

(Comparative Examples 1 and 2) As shown in Table 3 below, in Comparative Examples 1 and 2, the positive electrode was used as in Example 1
In Comparative Example 1, the same negative electrode as in Example 12 was used, and in Comparative Example 2, the same negative electrode as in Example 2 was used. The coefficient value of P ₁ is set to 0.95 in Comparative Examples 1 and ₂ , and the coefficient value of P ₂ is set to 2.0 in Comparative Example 1.
0, and in Comparative Example 2 it was 3.91.

[0093]

[Table 3]

Comparative Example 3 to Comparative Example 4 As shown in Table 3, in Comparative Example 3 to Comparative Example 4, the positive electrode was used in Example 9
In Comparative Example 3, the same negative electrode as in Example 12 was used, and in Comparative Example 4, the same negative electrode as in Example 2 was used. The coefficient value of P ₁ is set to 2.
11, the coefficient value of P ₂ was 2.00 in Comparative Example 3 and 3.91 in Comparative Example 4.

Comparative Example 5 to Comparative Example 6 As shown in Table 3, in Comparative Example 5 to Comparative Example 6, the positive electrode is used in Example 5
In Comparative Example 5, the same negative electrode as in Example 16 was used, and in Comparative Example 6, the same negative electrode as in Example 6 was used. The coefficient value of P ₁ is set to 0.96 in Comparative Examples 5 to 6, and the coefficient value of P ₂ is set to 2.0 in Comparative Example 5.
6 and Comparative Example 6 was set to 3.91.

(Comparative Examples 7 to 8) As shown in Table 3, in Comparative Examples 7 to 8, the positive electrode was used as in Example 1.
The same positive electrode as in Example 3 was used, and the negative electrode was used in Comparative Example 7 as Example 16
In Comparative Example 8, the same negative electrode as in Example 6 was used. The coefficient value of P ₁ is set to 2.15 in Comparative Examples 7 to 8 and the coefficient value of P ₂ is 2.0 in Comparative Example 7.
6 and Comparative Example 8 was set to 3.91.

(Comparative Examples 9 to 10) As shown in Table 3, in Comparative Examples 9 to 10, the same positive electrode as in Example 5 was used as the positive electrode, and the negative electrode in Comparative Example 9 was the same as in Example 5. 17
In Comparative Example 10, the same negative electrode as in Example 21 was used. The coefficient value of P ₁ is set as Comparative Example 9 to Comparative Example 1.
0 was 0.96, and the coefficient value of P ₂ was 2.01 in Comparative Example 9 and 3.91 in Comparative Example 10.

(Comparative Examples 11 to 12) As shown in Table 3, in Comparative Examples 11 to 12, the same positive electrode as that of Example 13 was used as the positive electrode, and the negative electrode of Comparative Example 11 was the same as that of Example 13. The same negative electrode as in Example 17 was used in Comparative Example 12, and the same negative electrode as in Example 21 was used in Comparative Example 12. The coefficient value of P ₁ is set as Comparative Example 11
And - Comparative Example 12 both 2.15, the coefficient values of _{P 2,} in Comparative Example 11 2.01 was Comparative Example 12, 3.91.

(Comparative Examples 13 to 14) As shown in Table 3, in Comparative Examples 13 to 14, the same positive electrode as in Example 31 was used as the positive electrode, and the negative electrode in Comparative Example 13 was as in Example 13. The same negative electrode as in Example 17 was used in Comparative Example 14, and the same negative electrode as in Example 21 was used in Comparative Example 14. The coefficient value of P ₁ is set to Comparative Example 13
And - Comparative Example 14 both 0.92, the coefficient values of _{P 2,} in Comparative Example 13 2.01, was 3.91 in Comparative Example 14.

(Comparative Examples 15 to 16) As shown in Table 3, in Comparative Examples 15 to 16, the same positive electrode as in Example 35 was used as the positive electrode, and the negative electrode in Comparative Example 15 was the same as that in Example 35. The same negative electrode as in Example 17 was used, and in Comparative Example 16, the same negative electrode as in Example 21 was used. The coefficient value of P ₁ is set as Comparative Example 15
And - Comparative Example 16 both 2.16, the coefficient values of _{P 2,} in Comparative Example 15 2.01, was 3.91 in Comparative Example 16.

Comparative Examples 17 to 18 As shown in Table 3, in Comparative Examples 17 to 18, the negative electrode was Comparative Example 1
In Comparative Example 18, the same negative electrode as in Example 36 was used, and in Comparative Example 18, the same negative electrode as in Example 40 was used. The coefficient value of P ₁ is set to 0.92 in Comparative Examples 17 to 18, and the coefficient value of P ₂ is 2.01 in Comparative Example 17 and 3.88 in Comparative Example 18.
And

Comparative Examples 19 to 20 As shown in Table 3, in Comparative Examples 19 to 20, the negative electrode was Comparative Example 1
In Comparative Example 9, the same negative electrode as in Comparative Example 17 was used, and in Comparative Example 20, the same negative electrode as in Comparative Example 18 was used. The coefficient value of P ₁ is 2.12 in Comparative Examples 19 to 20 and the coefficient value of P ₂ is 2.01 in Comparative Example 19 and 3.88 in Comparative Example 20.
And

<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 4.5 hours. Discharge condition is 5
A constant current and final voltage were 2.7V.

Further, 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, the batteries of Examples and Comparative Examples were repeatedly charged and discharged 100 times under the above-mentioned conditions, and then the output and the discharge capacity were measured in the same manner. Indicated by. As a matter of course, the higher the maintenance rate, the better the life characteristics.

The charging / discharging, the discharge capacity and the output were measured in an atmosphere having an ambient temperature of 25 ± 1 ° C.
The test results are shown in Tables 4 and 5 below.

[0108]

[Table 4]

[0109]

[Table 5]

As shown in Tables 4 and 5, Examples 1 to 1
In the battery of Example 40, both the capacity maintenance ratio and the output maintenance ratio were
A high battery was obtained. With the batteries of Comparative Example 1 to Comparative Example 20
Is P ₁Coefficient value of is less than 1.00 or 2.00
Exceed and P_TwoThe coefficient value of is less than 2.10 or 3.
Since it exceeds 80, both capacity maintenance ratio and output maintenance ratio are
Low battery, or either battery was significantly low.

On the other hand, Examples 2 to 4, Example 6 to Example 8 and Example 12 produced according to the first embodiment in which the coefficient value of P ₁ is 1.00 or more and 2.00 or less. In the batteries of Example 16, Example 17, Example 21, Example 36, and Example 40, at least one of the capacity retention rate and the output retention rate was higher than that of the battery of Comparative Example. Among them, Example 4, Example 7, Example 8 and Example 21 in which the coefficient value of P ₁ is 1.69 or more and 2.00 or less,
The capacity retention rate and the output retention rate were high in a well-balanced manner.

In addition, among the batteries manufactured according to the first embodiment, Example 1 in which the coefficient value of P ₂ is less than 2.10.
The batteries of 2, Example 16, Example 17, and Example 36 are
The capacity retention rate shows a slightly low value, and conversely, the batteries of Examples 2 to 4, Examples 6 to 8, Example 21 and Example 40 in which the coefficient value of P ₂ exceeds 3.80 are output retention rates. Showed a slightly lower value.

Example 1, Example 5, Example 9 to Example 11, Example 13 to Example 15, produced according to the second embodiment in which the coefficient value of P ₂ is 2.10 or more and 3.80 or less,
In the batteries of Examples 18 to 20, Example 31, and Example 35, at least one of the capacity retention rate and the output retention rate was higher than that of the battery of Comparative Example. Above all,
Example 1 in which the coefficient value of P ₂ is 2.86 or more and 3.80 or less
0, Example 11, Example 14, Example 15, Example 19
Also, in Example 20, the capacity retention ratio and the output retention ratio were high values in a well-balanced manner.

In the battery manufactured according to the second embodiment, the coefficient value of P ₁ is less than 1.00.
The batteries of Examples 5 and 31 exhibited a slightly lower capacity retention rate, and conversely, Examples 9 to 11 and Examples 13 to 15 in which the coefficient of P ₁ exceeded 2.00. The batteries of Examples 18 to 20 and Example 35 had slightly lower output retention rates.

Examples 22 to Examples produced according to the third embodiment in which the coefficient value of P ₁ is 1.00 or more and 2.00 or less and the coefficient value of P ₂ is 2.10 or more and 3.80 or less. Three
In the batteries of No. 0, Examples 32 to 34, and Examples 37 to 39, both the capacity retention rate and the output retention rate were extremely high values. Above all, the coefficient value of P ₁ is 1.69 or more, 2.0
0 or less, and the coefficient value of P ₂ is 2.94 or more and 3.80
Example 26, Example 27, Example 29, and Example 3 below
In Example 0 and Example 34, the capacity retention rate and the output retention rate were well balanced and exhibited extremely high values.

Regardless of any of the above embodiments, Examples 3-A, 5-A, 7-A, 9-A, 10-A, 12 using thermosetting plasticized polyvinyl alcohol as a binder.
-A, 16-A, 17-A, 21-A, 22-A, 23
-A, 26-A, 28-A, 29-A, 32-A, 33
-A, 34-A, 35-A, 38-A, 39-A, 40
In the case of -A, both the output retention rate and the capacity retention rate were higher than those of the batteries of Examples corresponding to PVDF binders.

As is apparent from a number of examples and comparative examples, according to the first embodiment, regardless of the type of lithium-transition metal composite oxide, the composition of the positive electrode mixture, and the coating amount, the above-mentioned matters are given. By satisfying the expression (1), it is possible to obtain the long-life cylindrical lithium-ion battery 20 excellent in at least one of the capacity retention rate and the output retention rate. In this case,
If the above equation (2) is satisfied, the capacity and the output can be maintained in a well-balanced manner. Further, according to the second embodiment, the capacity maintenance ratio and the output maintenance ratio are satisfied by satisfying the above formula (3) regardless of the types of the negative electrode carbon material and conductive material, the composition of the negative electrode mixture material, and the coating amount. It is possible to obtain a long-life cylindrical lithium-ion battery 20 in which at least one of them is excellent. In this case, if the above-mentioned formula (4) is satisfied, the capacity and the output can be maintained in a well-balanced manner. Furthermore, according to the third embodiment, the operational effects of the first embodiment and the second embodiment are simultaneously achieved,
It is possible to obtain the cylindrical lithium-ion battery 20 having a further long life, which is extremely excellent in both the capacity retention rate and the output retention rate.
Further, this function and effect are more remarkably exhibited by using the thermosetting plasticized polyvinyl alcohol as the binder of the electrode. Such a long-life lithium-ion battery is suitable for a power source of an electric vehicle, which has a long usage period.

In the above 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 generally 3 to 30 Ah to 100.
It has been confirmed that the present invention exerts a remarkable effect on a battery of about Ah. Further, although the cylindrical battery is exemplified in the above embodiment, the present invention is not limited to the shape of the battery, and can be applied to a prismatic battery or other polygonal battery or a stack type battery. Furthermore, the applicable shape of the present invention 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 above embodiment, lithium manganate or lithium cobalt oxide is used for the positive electrode of the lithium ion battery, amorphous carbon or graphite is used for the negative electrode, and the volume ratio of ethylene carbonate, dimethyl carbonate and diethyl carbonate is 1 for the non-aqueous electrolyte. A mixture of 1: 1 and 1 mol / liter of lithium hexafluorophosphate was used.
The battery of the present invention is not particularly limited, and any of commonly used conductive materials and binders can be used. In general, lithium manganate can be synthesized by mixing a suitable lithium salt such as lithium carbonate with manganese dioxide such as manganese dioxide 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.

Further, as the binder (binding material) for the non-aqueous electrolyte secondary battery which can be used in the other embodiments, Teflon (registered trademark), polyethylene, polystyrene, polybutadiene, butyl rubber, nitrile rubber, styrene are used. / Butadiene rubber, polysulfide rubber, nitrocellulose
, Cyanoethyl cellulose, various latexes, acrylonitrile, vinyl fluoride, vinylidene fluoride, propylene fluoride, polymers such as chloroprene fluoride and mixtures thereof, but as shown in this example, thermosetting By using the plasticized polyvinyl alcohol resin composition, it is possible to obtain a battery having an extremely high capacity and an extremely high output retention rate even after repeated high temperature charge / discharge cycles.

The lithium-transition metal composite oxide used in the present invention is preferably a material capable of inserting and releasing lithium, and is preferably a lithium-manganese composite oxide in which a sufficient amount of lithium has been inserted in advance, and has a spinel structure. Lithium manganate having a part of manganese and lithium in the crystal other than them, for example, Fe, Co, Ni, Cr, A1, M
It is also possible to use a material which is substituted or doped with an element such as g or a material in which a part of oxygen in the crystal is substituted or doped with an element such as S or P. Other than these, the effect of the present invention is not changed even if a lithium manganese composite oxide capable of a battery voltage of 5 V is used.

Further, the carbon material for the negative electrode used in the present invention 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.

Further, in the above embodiment, the surface area of each material was obtained by the nitrogen adsorption method, but the surface area may be obtained by another method, for example, the wet heat method.

Furthermore, as the non-aqueous electrolyte, an electrolyte in which a general lithium salt is used as an electrolyte and this is dissolved in an organic solvent is used. The lithium salt and organic solvent used are not particularly limited. For example, as the electrolyte, LiCl
0 ₄ , LiAsF ₆ , LiPF ₆ , LiBF ₄ , LiB
(C ₆ H ₅ ) ₄ , CH ₃ S0 ₃ Li, CF ₃ S0 ₃ Li
Etc. and mixtures thereof can be used. As the non-aqueous electrolyte organic solvent, propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, γ-butyrolactone, tetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3- Dioxolane, diethyl ether, sulfolane, methylsulfolane, acetonitrile, propionitrile, etc., or a mixed solvent of two or more kinds of these may be used, and the mixing ratio is not limited.

Further, in the above-described 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 for 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.

[0126]

As described above, according to the present invention,
By setting the ratio B ₁ / S ₁ within the range of the formula (1) with respect to the coating amount P ₁ , peeling and dropping of the coated positive electrode mixture material are prevented, and the electrode reaction area with the non-aqueous electrolyte solution is prevented. It is possible to obtain the effect that it is possible to suppress the decrease in capacity and output retention rate due to charge and discharge cycles, and to realize a long-life non-aqueous electrolyte secondary battery. You can

[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 2 Positive Electrode Lead Piece 3 Negative Electrode Lead Piece 4 Positive Electrode Current Collection Ring 5 Negative Current Collection Ring 6 Winding Group (Electrode Group) 7 Battery Container 8 Negative Electrode Lead Plate 9 Positive Electrode Lead 10 Gasket 11 Cleavage Valve 12 Lid Case 13 Lid Cap 14 Valve retainer 20 Cylindrical lithium ion battery (non-aqueous electrolyte secondary battery) W1 Positive electrode current collector W2 Positive electrode mixture layer W3 Negative electrode current collector W4 Negative electrode mixture layer W5 Separator

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5H029 AJ02 AJ03 AJ05 AK03 AL06                       AL07 AL08 AM02 AM03 AM04                       AM05 AM07 BJ02 CJ22 DJ07                       DJ08 EJ12 HJ00 HJ01 HJ07                 5H050 AA02 AA07 AA08 BA17 CA08                       CA09 CB07 CB08 CB09 DA04                       DA10 DA11 EA08 EA23 GA22                       HA00 HA01 HA07

Claims (7)

[Claims] 1. A lithium-transition metal complex oxide and carbon are used.
Positive electrode mixture containing conductive material and binder as positive electrode current collector
An electrode having a coated positive electrode, a negative electrode, and a separator
Non-water stored in the battery container by immersing the group in non-aqueous electrolyte
In the electrolyte secondary battery, the unit mass of the positive electrode mixture material
The mass of the binder contained per (g) is B
₁(G) and contained per unit mass of the positive electrode mixture
Sum of the lithium transition metal complex oxide and the conductive material
Surface area is S₁(M^Two) And a single-sided unit of the positive electrode current collector
Area (m^Two) Is the coating amount of the positive electrode mixed material per P
₁(G / m ^Two), The total surface area S₁Against
Mass B₁Ratio B of₁/ S₁Satisfies the following formula (1)
A non-aqueous electrolyte secondary battery characterized in that [Equation 1] 2. The non-aqueous electrolyte secondary battery according to claim 1, wherein the ratio B ₁ / S ₁ satisfies the following formula (2). [Equation 2] 3. Lithium ion storage / release by charge / discharge
Negative containing carbon material, binder and optionally conductive material
The negative electrode in which the negative electrode current collector is coated with the electrode mixture material, the positive electrode, and the separator.
And the electrode group having
In the non-aqueous electrolyte secondary battery housed in the pond container,
The bar contained per unit mass (g) of the negative electrode mixture material
Inda mass is B_Two(G) is the unit of the negative electrode mixture
Total table of the carbon material and the conductive material contained per mass
Area is S_Two(M^Two) And one side of the negative electrode current collector
Product (m^Two), The coating amount of the negative electrode mixture material per_Two(G
/ M^Two), The total surface area S_TwoBefore
Mass B_TwoRatio B of_Two/ S _TwoSatisfies the following formula (3)
A non-aqueous electrolyte secondary battery characterized by: [Equation 3] 4. The non-aqueous electrolyte secondary battery according to claim 3, wherein the ratio B ₂ / S ₂ satisfies the following formula (4). [Equation 4] 5. A positive electrode having a positive electrode current collector coated with a positive electrode mixture containing a lithium-transition metal complex oxide, a conductive material using carbon, and a binder, and occluding lithium ions by charging and discharging.
A negative electrode in which a negative electrode mixture material containing a releasable carbon material, a binder and a conductive material is coated on a negative electrode current collector, and a separator, and an electrode group having a non-aqueous electrolyte is soaked into a battery container. In the accommodated non-aqueous electrolyte secondary battery, the mass of the binder contained per unit mass (g) of the positive electrode mixture is B ₁ (g), and contained per unit mass of the positive electrode mixture. The total surface area of the lithium transition metal complex oxide and the conductive material is S ₁ (m ² ), and the amount of the positive electrode mixture applied per unit surface area (m ² ) of the positive electrode current collector is P ₁ (g / g / m ² ), and the mass of the binder contained per unit mass (g) of the negative electrode mixture material is B ₂ (g), and the carbon material contained per unit mass of the negative electrode mixture material, The total surface area of the conductive material is S ₂ (m
² ) and the coating amount of the negative electrode mixture material per unit surface area (m ² ) of the negative electrode current collector is P ₂ (g / m ² ), the mass B with respect to the total surface area S ₁ wherein the ₁ ratio _B 1 / _{S 1} is to satisfy the following formula (5-1), and the mass ratio _B 2 / _{S 2} of the _{B 2} with respect to the total surface area _{S 2} satisfies the following equation (5-2) And a non-aqueous electrolyte secondary battery. [Equation 5] 6. The ratio B ₁ / S ₁ satisfies the following formula (6-1), and the ratio B ₂ / S ₂ satisfies the following formula (6-2). The non-aqueous electrolyte secondary battery described. [Equation 6] 7. The binder according to claim 1, wherein the binder is a thermosetting plasticized polyvinyl alcohol resin mainly composed of polyvinyl alcohol and modified.
The non-aqueous electrolyte secondary battery according to any one of 1.