JP2002270240A - Nonaqueous secondary cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a large-sized nonaqueous secondary cell of which, electrodes and separator can be correctly and easily laminated, which is used for a storage cell system with high productivity, high energy density, and high reliability and safety. SOLUTION: For the flat-shaped nonaqueous secondary cell with a thickness of less than 12 mm, housing a positive electrode, a negative electrode, a separator and nonaqueous electrolyte containing lithium salt in a cell container, with energy capacity of not less than 30 Wh, and volume energy density of 180 Wh/l, a wound structure is formed by winding a laminated body laminating the belt-shaped positive electrode, the belt-shaped negative electrode, a belt- shaped separator laid between the positive electrode and the negative electrode, and the other belt-shaped separator arranged at the outside of either one of the positive electrode or the negative electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous secondary battery, and more particularly to a non-aqueous secondary battery for a power storage system.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of effective use of energy for resource saving and global environmental problems, a home-use decentralized power storage system for late-night power storage and power storage for photovoltaic power generation has been developed. Power storage systems are attracting attention. For example, JP-A-6-86463 discloses that
As a system capable of supplying energy to an energy consumer under optimum conditions, a total system combining electricity supplied from a power plant, gas cogeneration, a fuel cell, a storage battery, and the like has been proposed. A secondary battery used in such a power storage system has an energy capacity of 10
Unlike small secondary batteries for portable devices of Wh or less, large batteries having large capacities are required. For this reason, in the above-described power storage system, a plurality of secondary batteries are stacked in series, and usually used as a battery pack having a voltage of, for example, 50 to 400 V. In most cases, a lead battery is used.

On the other hand, in the field of small rechargeable batteries for portable equipment, nickel-metal hydride batteries and lithium rechargeable batteries have been developed as new types of batteries in order to meet the needs of small size and high capacity, and volume energy of 180 Wh / l or more has been developed. Batteries having a density are commercially available. In particular, lithium-ion batteries
It has a potential for volume energy density exceeding 350 Wh / l, and is superior in reliability such as safety and cycle characteristics as compared with lithium secondary batteries using lithium metal as a negative electrode, so that the market is dramatically improved. To be extended.

[0004] In response to this, in the field of large-sized batteries for power storage systems, lithium-ion batteries have been targeted as candidates for high-energy density batteries, and lithium battery power storage technology research associations (LIBES) and others have been vigorously developing them. Have been.

The energy capacity of these large lithium ion batteries is about 100 Wh to 400 Wh, and the volume energy density is 200 to 300 Wh / l, which is at the level of a small secondary battery for portable equipment. Its shape is
Diameter 50mm-70mm, length 250mm-450mm
And a rectangular prism having a thickness of 35 mm to 50 mm or an oblong prism or the like are typical.

[0006]

In assembling these large lithium-ion batteries, for example, in the case of a cylindrical shape, a laminate of a positive electrode, a separator and a negative electrode is wound or folded to form an electrode unit, and the battery is inserted into the battery. Be incorporated. In the case of a prismatic battery, a positive electrode, a separator, and a laminate of a negative electrode are wound or folded to form an electrode unit,
Built into the battery. Furthermore, a plurality of positive electrodes, separators, and an electrode unit stacked (stacked) a negative electrode in this order, is incorporated into the battery. Among these, the winding or folding system is considered to be a system in which the positive electrode, the negative electrode, and the separator can be easily positioned and has high mass productivity, and the stack system is considered to be inferior to the above system.

However, unlike a small battery, the length of a wound or folded electrode is several times to 10 times or more in a large battery. Therefore, in a large battery, the internal resistance is considered in consideration of the internal resistance. It is necessary to devise current collection,
As shown in FIG. 10A, in a structure similar to a small battery in which the current collecting tab 201 is provided at one end of the electrode 200, the internal resistance of the battery increases.

Therefore, as shown in FIG.
11 in which a plurality of current collecting tabs 201 are provided in FIG.
As shown in (a), an electrode 3 having a current collecting piece 301 on which one side of a length direction of a positive electrode and a negative electrode is not coated with an electrode material.
As shown in FIGS. 11B and 11C, the current collecting piece 301 with a plurality of current collecting tabs 302 attached thereto is used as a positive electrode 300a (300), a separator and a negative electrode 300b (3).
00) is wound into a cylindrical shape,
As shown in FIG. 11D, the electrode unit 304 in which a separator is interposed between the positive electrode 300a (300) and the negative electrode 300b (300) is formed by winding in a rectangular shape, and the electrode unit 304 is mounted inside the battery. A method of arranging them in a location has been proposed.

However, in either case, the current collecting structure becomes complicated, and the winding or folding method, which has been used in small batteries, is considered to be a method of mass productivity for large batteries. I can't.

[0010] In addition, as described above, although a large lithium-ion battery can provide a high energy density, since its battery design is an extension of a small battery for a portable device, its diameter or thickness is small. The battery shape is more than three times the shape of a cylinder or square, and the heat dissipation is insufficient, the battery temperature rises, and the battery is put in an unfavorable state. , and further such as reliability induction of thermal runaway of the battery, was not a problem is left to the particular safety.

An object of the present invention is to provide a large-sized non-aqueous secondary battery used in a power storage system or the like which has a simple current collection structure, can easily and accurately laminate an electrode and a separator, and is used for a mass storage system. is there.

Another object of the present invention is to provide a large non-aqueous secondary battery used for a power storage system or the like with high energy density, high reliability and high safety.

[0013]

SUMMARY OF THE INVENTION The present invention provides the following non-aqueous secondary battery to achieve the above object.

A non-aqueous secondary battery contains a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt in a battery container, has a flat shape with a thickness of less than 12 mm, and has an energy capacity of 30 Wh or more and a volume. energy density is 18
A non-aqueous secondary battery of 0 Wh / l or more, wherein a strip-shaped positive electrode, a strip-shaped negative electrode, a strip-shaped separator interposed between the positive electrode and the negative electrode, and one of the positive electrode and the negative electrode are provided outside. It is characterized in that a laminated body is formed by laminating another belt-shaped separator to be disposed, and the laminated body is wound into a wound structure.

The non-aqueous secondary battery contains a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt in a battery container, and has a flat shape with a thickness of less than 12 mm.
What is claimed is: 1. A non-aqueous secondary battery having an energy capacity of 30 Wh or more and a volume energy density of 180 Wh / l or more, wherein the positive electrode and the negative electrode are folded in a zigzag shape in a state where a positive electrode and a negative electrode are combined. And a separator interposed therebetween.

In these non-aqueous secondary batteries, it is desirable to form a current collecting piece along one longitudinal side of the positive electrode and the negative electrode.

Further, it is preferable that the positive electrode current collector and the negative electrode current collector are located on opposite sides, and the separator, the positive electrode current collector and the negative electrode current collector are stacked so as not to overlap with each other. desirable.

The pressed against the current collector piece to form a collecting voltage contact portion, it is desirable to configure to connect the said population voltage contact portion to the terminal, the positive electrode, to mainly the manganese-based oxide Preferably, the negative electrode desirably contains a material capable of doping and undoping lithium, the shape of the flat front and back surfaces is desirably rectangular, and the thickness of the battery container is 0.2 mm. It is desirable that it is not less than 1 mm.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A non-aqueous secondary battery according to one embodiment of the present invention will be described below with reference to the drawings. 1A and 1B are a plan view and a side view of a flat rectangular (notebook) non-aqueous secondary battery for a power storage system according to an embodiment of the present invention, and FIG. 2 shows an electrode unit 100 housed inside the battery shown.

As shown in FIGS. 1 and 2, a non-aqueous secondary battery according to the present embodiment includes a battery container including an upper lid 1 and a bottom container 2, and a strip-shaped positive electrode housed in the battery container. 1
01a, a strip-shaped negative electrode 101b, and an electrode unit 100 in which a laminate of two strip-shaped separators 104 is wound.

The shape of the non-aqueous secondary battery shown in FIGS. 1 and 2 is, for example, 300 mm × 210 mm × 6 m in thickness.
m, LiMn ₂ O _{4 on} the positive electrode 101a, the negative electrode 101
A lithium secondary battery using a carbon material for b and 101c is:
For example, it can be used for a power storage system.

[0022] The positive electrode current collector 105 that make up the positive electrode 101a
a is electrically connected to the positive electrode terminal 3, and
The negative electrode current collector 105b included in the negative electrode terminal 01b is electrically connected to the negative electrode terminal 4. In the present invention, the method of connecting the current collector to the terminal is not particularly limited, but in the present embodiment, a winding method will be described as an example of a preferable method.

As for the positive electrode 101a and the negative electrode 101b, a current collector in which the electrode material is not applied to one side in the length direction shown in FIG. 12A is used. 106a and the negative electrode current collector 106b. Positive electrode 101a, negative electrode 101b, and separator 104
Is wound as shown in FIG. 2 to obtain the electrode unit 100.

FIGS. 6 and 7 show a method of manufacturing the electrode unit 100, in which a positive electrode 101a, a negative electrode 101b, and a separator 101 are supplied from a supply portion in which a positive electrode 101a, a negative electrode 101b, and two separators 104 are wound in a roll shape. 104 are supplied, and these are stacked and wound by a plate-shaped winding body B rotating about the rotation axis B1.

That is, the positive electrode current collector 106a and the negative electrode current collector 106b are located on opposite sides (both sides of the electrode unit 100), and the electrode material application portions of the positive electrode 101a and the negative electrode 101b overlap with the separator 104 interposed therebetween. , Positive electrode 101
a or the negative electrode 10a so that another separator 104 overlaps the electrode material application portion outside the negative electrode 101a or the negative electrode 101b.
Winding body B while laminating 1b and separator 104
And the electrode unit 100 is obtained.

Then, as shown in FIG. 3 (a), the positive current collector 106a and the negative current collector 106b located on both sides of the electrode unit 100 are crushed, respectively, to collect the current collecting contact 108a and the negative current collecting 108b. Then, the current collecting contact portion 108a and the negative electrode current collecting contact portion 108b are connected to the positive current collecting tab 7 and the negative current collecting tab 8 by a simple method such as welding. Since the non-aqueous secondary battery of the present invention has a flat shape with a thickness of less than 12 mm, the thickness of the electrode unit is naturally reduced, and such a current collecting tab 7, which has been difficult with a conventional large secondary battery. 8 becomes possible.

The upper lid 1 and the bottom container 2 are welded by melting the entire circumference of the upper lid at a point A shown in an enlarged view in FIG. An electrolyte injection port 5 is opened in the upper lid 1.
After the injection of the electrolyte, the container is sealed with a sealing film 6 made of, for example, an aluminum-modified polypropylene laminated film. More preferably, the final sealing step is performed after at least one charging operation. The pressure in the battery container after the final sealing step with the sealing film 6 is preferably lower than the atmospheric pressure, and more preferably 86659.3.
Pa (650 Torr) or less, particularly preferably 7332
It is 7.1 pa (550 Torr) or less. This pressure is determined in consideration of the separator used, the type of electrolyte, the material and thickness of the battery container, the shape of the battery, and the like. When the internal pressure is equal to or higher than the atmospheric pressure, the battery tends to be larger than the designed thickness, or the thickness of the battery tends to vary widely, and the internal resistance and capacity of the battery tend to vary.

The positive electrode active material used for the positive electrode 101a is not particularly limited as long as it is a lithium-based positive electrode material. A lithium composite cobalt oxide, a lithium composite nickel oxide, a lithium composite manganese oxide, or a mixture thereof is used. Further, a system in which one or more different metal elements are added to these composite oxides can be used, and a high-voltage, high-capacity battery can be obtained, which is preferable. In addition, when importance is placed on safety, which is the highest priority in practical application of a large lithium secondary battery, a manganese oxide having a high thermal decomposition temperature is preferable. As this manganese oxide, LiMn ₂ O ₄
Lithium composite manganese oxides represented by the above, furthermore, a system in which one or more different metal elements are added to these composite oxides, and further, Li _{1 + x} Mn in which lithium is exceeded in a stoichiometric ratio
_2-y O _{4 and the} like. In particular, the present invention has a great effect when a positive electrode mainly composed of the manganese oxide is used.

The negative electrode active material used for the negative electrode 101b is not particularly limited as long as it is a lithium-based negative electrode material. A material capable of doping and undoping lithium can be used for reliability, such as safety and cycle life. It is preferable because the property is improved. Materials capable of doping and undoping lithium include graphite-based materials, carbon-based materials, tin oxide-based, silicon oxide-based metal oxides, and polyacene-based materials that are used as negative electrode materials for known lithium ion batteries. Conductive polymers typified by organic semiconductors and the like can be given.

The separator 104 configuration is not particularly limited, it can be used a separator of a single layer or multiple layers, at least one preferably used nonwoven fabric, in this case, the cycle characteristics are improved . Also, the material of the separator 104 is not particularly limited, but examples thereof include polyolefins such as polyethylene and polypropylene, polyamide, kraft paper, glass, and cellulosic materials, depending on the heat resistance and safety design of the battery. It is determined as appropriate.

As the electrolyte of the non-aqueous secondary battery of the present embodiment, a known non-aqueous electrolyte containing a lithium salt can be used, which is appropriately determined according to the conditions of use such as a positive electrode material, a negative electrode material, and a charging voltage. More specifically, LiPF ₆ , L
Lithium salts such as iBF ₄ and LiClO ₄ are mixed with propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, dimethoxyethane, γ-butyrolactone, methyl acetate, methyl formate, or a mixed solvent of two or more of these. Examples thereof include those dissolved in an organic solvent. Further, the concentration of the electrolytic solution is not particularly limited, but is generally set at 0.1.
5 mol / l to 2 mol / l is practical, and it is preferable to use, as a matter of course, an electrolyte having a water content of 100 ppm or less. In addition, the non-aqueous electrolyte used in this specification means a concept including a non-aqueous electrolyte and an organic electrolyte, and also a concept including a gel or solid electrolyte.

The non-aqueous secondary battery constructed as described above is used in a home power storage system (nighttime power storage, cogeneration system).
, Solar power generation, etc.), electric storage systems for electric vehicles, etc., and can have large capacity and high energy density. In this case, the energy capacity is
It is preferably at least 30 Wh, more preferably at least 50 Wh, and the energy density is preferably at least 180 Wh.
/ L or more, more preferably 200 Wh / l. When the energy capacity is less than 30 Wh or when the volume energy density is less than 180 Wh / l, the capacity is small for use in a power storage system, and it is necessary to increase the number of series-parallel batteries in order to obtain a sufficient system capacity. That also
It is not preferable for a power storage system because a compact design is difficult.

The non-aqueous secondary battery of the present embodiment has a flat shape and a thickness of less than 12 mm, more preferably less than 10 mm. The lower limit of the thickness is practically 2 mm or more in consideration of the filling rate of the electrode and the battery size (the smaller the thickness, the larger the area for obtaining the same capacity). When the thickness of the battery is 12 mm or more, it is difficult to sufficiently radiate the heat generated inside the battery to the outside, or the temperature difference between the inside of the battery and the vicinity of the battery surface increases,
As a result of the difference in the internal resistance, the amount of charge and the voltage in the battery vary widely. The specific thickness depends on the battery capacity,
Although it is appropriately determined according to the energy density, it is preferable to design the maximum thickness so as to obtain expected heat radiation characteristics.

The shape of the non-aqueous secondary battery of the present embodiment is, for example, that the flat front and back surfaces are square, circular,
It can be of various shapes such as an oval, and in the case of a square, it is generally a rectangle, but it can also be a polygon such as a triangle or a hexagon. Further, it may be a cylindrical shape such as a thin-walled cylinder. In the case of a cylindrical shape, the thickness of the cylinder is the thickness referred to here. Further, from the viewpoint of ease of production, the flat front and back surfaces of the battery are preferably rectangular, and a notebook-type shape as shown in FIG. 1 is preferable.

The materials used for the upper lid 1 and the bottom container 2 serving as the battery container are appropriately selected depending on the use and shape of the battery.
There is no particular limitation, and iron, stainless steel, aluminum and the like are common and practical. Also, the thickness of the battery container is appropriately determined depending on the use and shape of the battery or the material of the battery case, and is not particularly limited. Preferably, the thickness of a portion of 80% or more of the battery surface area (the thickness of the portion having the largest area constituting the battery container) is 0.2 mm or more. If the thickness is less than 0.2 mm, the strength required for manufacturing the battery cannot be obtained, which is not desirable. From this viewpoint, the thickness is more preferably 0.3 mm or more. Further, it is desirable that the thickness of the portion is 1 mm or less. When the thickness exceeds 1 mm, the force for pressing down the electrode surface increases, but it is not desirable because the internal volume of the battery is reduced and a sufficient capacity cannot be obtained, or the weight increases, which is not desirable. Preferably 0.
7 mm or less.

As described above, the thickness of the non-aqueous secondary battery is set to 1
By designing it to be less than 2 mm, for example,
When the battery has a large capacity of 0 Wh or more and a high energy density of 180 Wh / l, the battery temperature rise is small even during high-rate charging and discharging, and excellent heat radiation characteristics can be obtained. Therefore, heat storage of the battery due to internal heat generation is reduced, resulting in thermal runaway also becomes possible to prevent reliability of the battery, it is possible to provide a nonaqueous secondary battery excellent in safety.

FIGS. 8 and 9 show another embodiment. The electrode unit of the present embodiment includes a strip-shaped positive electrode 101.
a ′, strip-shaped negative electrode 101 c and strip-shaped separator 104
Are laminated in a zigzag shape. The positive electrode 101a ′ and the negative electrode 101c
The current collector 105a 'and the current collector 105c are provided with the electrode material application portions 102a' and 102c only on one surface thereof, and are otherwise the same as the positive electrode 101a and the negative electrode 101b. This electrode unit is manufactured by the folding device C described below.

When the positive electrode 101a ', the negative electrode 101c, and the separator 104 are laminated, as shown in FIG.
a ′, the electrode material coated portions 102a ′ and 10 of the negative electrode 101c.
2c is brought into contact with the separator 104, and the positive electrode current collector 106a 'of the positive electrode 101a' and the negative electrode current collector 10
6c on both sides of the separator 104.

As shown in FIG. 9, the folding device C includes a supply section C3 in which a positive electrode 101a ', a negative electrode 101c, and a separator 104 are respectively wound in a roll shape, a positive electrode 101a' supplied from the supply section C3, and a negative electrode 101a '. A roll pair C2 for laminating 101c and the separator 104 to move the laminated body 100a downward, a folding habit means C2 for imparting a folding habit 100b to the laminated body 100a, and a non-illustrated control for generally controlling these means. and a means.

A pair of folding habit means C1 are arranged on the side of the laminated body 100a so as to have different heights, and each of the folding habit means C1 has a male portion C11 and a female portion C1 for forming a folding habit.
2 is provided. As shown in FIG. 9, the male part C11 reciprocates in the X1 direction, the female part C12 reciprocates in the X2 direction, and the male part C11 and the female part C12 are stacked when they match while sandwiching the stacked body 100a. Folding part 100 on body 100a
b is formed, lowers the stack 100a marked with a habit portion 100b folded away the male portion C11 and the female portion C12 on the bed C4. Then, by repeating this operation, the stacked body 100a is folded in a zigzag shape to form an electrode unit. Incidentally, the positive electrode 101a 'and the anode 101c
Are bent, the current collectors 105a 'and 105
The electrode non-applied surfaces c overlap each other.

The positive current collector 106a 'and the negative current collector 106c located on both sides of the electrode unit are respectively crushed to form a current collecting contact portion and a negative current collecting contact portion, as described above. This is the same as the embodiment.

[0042]

The present invention will be described more specifically below with reference to examples of the present invention. (Example 1) (1) 100 parts by weight of LiMn ₂ O ₄ , 8 parts by weight of acetylene black, polyvinylidene fluoride (PVDF) 3
The mixture was mixed with 100 parts by weight of N-methylpyrrolidone (NMP) to obtain a positive electrode mixture slurry. Thick the slurry 2
After coating and drying on both sides of a 0 μm aluminum foil (current collector), pressing was performed to obtain a positive electrode. FIG. 4A is an explanatory diagram of the positive electrode. In this embodiment, the positive electrode 101a has a width W
Is 110 on both sides of a current collector having a thickness of 162 mm and a thickness of 20 μm.
It is applied with a thickness of μm. As a result, the thickness t of the electrode material application portion is 240 μm. In addition, the positive electrode current collector 10 in which the electrode material is not applied in the length direction of the electrode.
6a is provided with a width of 15 mm.

(2) Graphitized mesocarbon microbeads (MCMB, manufactured by Osaka Gas Chemical Co., Ltd., product number 6-28) 10
0 parts by weight and 10 parts by weight of PVDF were mixed with 90 parts by weight of NMP to obtain a negative electrode mixture slurry. When the slurry has a thickness of 14
After coating and drying on both sides of a copper foil (collector) of μm, pressing was performed to obtain a negative electrode. FIG. 4B is an explanatory diagram of the negative electrode. The negative electrode 101b has a width W of 165 mm and a thickness of 14 mm.
On both sides of μm of the current collector 105b is applied to a thickness of 90 [mu] m. As a result, the thickness t of the electrode material coating unit 194
It has become a μm. Further, a negative electrode current collecting piece 106b on which an electrode material is not applied is provided in a length direction of the electrode by 15 mm in width.

[0044] (3) As shown in FIG. 2, (1) one of the positive electrode 101a obtained in section a piece of the negative electrode 101b separator A (rayon, having a basis weight 12.6 g / m ²⁾ and the separator B (polyethylene microporous membrane; basis weight 13.3 g / m
² ) was wound as shown in FIG. 2 through a separator 104 (width W was 168 mm). The separator 104 was disposed such that the separator A was on the positive electrode side and the separator B was on the negative electrode side. Then, as shown in FIG.
The positive electrode current collecting piece 106a was crushed, and an aluminum plate having a thickness of 0.3 mm was welded as the positive electrode current collecting tab 7. The shape of the positive electrode current collector tab 7 is shown in FIG. 3, the hole 7a for attaching the positive electrode terminal 3 is opened. Similarly, the negative electrode current collector 106b was crushed, and a nickel plate having a thickness of 0.5 mm was welded as the negative electrode current collector tab 8. The shape of the negative electrode current collector tab 8 is shown in FIG. 3, the holes 8 for attachment to the negative terminal 4
a is opened.

(4) As shown in FIG.
Of the SUS304 thin plate was squeezed to a depth of 5 mm to prepare the bottom container 2, and the upper lid 1 was also formed of a 0.5 mm thick SUS304 thin plate. Next, as shown in FIG. 5, a positive electrode terminal 3 made of aluminum and a negative electrode terminal 4 made of copper
mmφ, a threaded portion at the tip M3). The positive and negative terminals 3 and 4 were insulated from the upper lid 1 by a polypropylene gasket 9.

(5) The holes of the respective positive electrode tabs 7 of the electrode unit prepared in the above item (3) are inserted into the positive electrode terminal 3, and the holes of the respective negative electrode tabs 8 are inserted into the negative electrode terminal 4. in the connection. The connected electrode laminate was fixed with an insulating tape, and the corner A of FIG. 1 was laser-welded over the entire circumference. Thereafter, the liquid inlet 5 1 of ethylene carbonate and diethyl carbonate as the electrolyte solution from (diameter: 6 mm) shown in Figure 1: was injected a solution obtained by dissolving LiPF ₆ at a concentration of 1 mol / l in mixed solvent 1 weight ratio. Next, the liquid injection port 5 was temporarily closed under atmospheric pressure using a bolt for temporary fixing.

(6) This battery is charged to a current of 5 A up to 4.2 V, and then a constant current and constant voltage charging of applying a constant voltage of 4.2 V is performed for 12 hours, and then a constant current of 5 A is applied to the battery.
Discharged to 5V.

(7) Remove the temporary fixing bolt of the battery,
Again, under a reduced pressure of 4.00 × 10 ⁴ Pa (300 Torr), a sealing film 6 made of an aluminum foil-modified polypropylene laminate film having a thickness of 0.08 mm and punched into 12 mmφ was heated at a temperature of 250 to 350 ° C. and a pressure of 1 to 1 mm. 3
The liquid injection port 5 was finally sealed by heat fusion under the conditions of kg / cm ² and a pressurization time of 5 to 10 seconds to obtain a flat notebook battery having a thickness of 6 mm.

[0049] charged to 4.2V the battery 5A of current conducted thereafter 4.2V constant current constant voltage charging for 12 hours to apply a constant voltage, followed by discharge at 5A constant current to 2.5V And checked the capacity. The discharge capacity was 21.6 Ah. (Capacity: 78 Wh, energy density: 210 W
h / l)

[0050]

According to the non-aqueous secondary battery of the present invention, by flattening the laminate, the thickness of the battery can be reduced and the amount of heat storage can be suppressed, and the life of the battery due to decomposition of the electrolytic solution and the like can be reduced. Thermal runaway can be prevented, and the reliability of large batteries
Safety can be improved.

Also, by folding the laminate of the positive electrode, the negative electrode, and the separator in a zigzag manner, the thickness of the battery can be reduced and the amount of heat storage can be suppressed, and the same effect can be obtained.

Further, since the positive electrode current collectors and the negative electrode current collectors can be brought close to each other, the positive electrode current collectors and the negative electrode current collectors can be crushed and connected directly to the terminals, respectively. As a result, a current collecting tab becomes unnecessary and the current collecting structure can be simplified.

[Brief description of the drawings]

FIG. 1A is a plan view of a non-aqueous secondary battery for a power storage system according to an embodiment of the present invention, and FIG. 1B is a side view of the non-aqueous secondary battery for a power storage system.

2A is a side view showing an example of the configuration of an electrode unit housed inside the battery shown in FIG. 1, and FIG.
FIG.

FIG. 3A is a side view illustrating connection of a current collecting tab to an electrode unit of a non-aqueous secondary battery for a power storage system according to an embodiment of the present invention, and FIG. 3B is a plan view thereof.

FIG. 4 is an explanatory diagram of a positive electrode, a negative electrode, and a separator used in an example of the nonaqueous secondary battery of the present invention.

FIG. 5 is an explanatory diagram of a battery container used in an embodiment of the non-aqueous secondary battery of the present invention.

FIG. 6 is a perspective view illustrating a method for manufacturing an electrode unit.

7 is a side view showing a manufacturing method of the electrode unit.

FIG. 8 is a perspective view illustrating a method for manufacturing an electrode unit according to another embodiment of the present invention.

FIG. 9 is a side view showing the same manufacturing method.

FIG. 10 is a view showing electrodes of a conventional non-aqueous secondary battery.

FIG. 11 is a diagram illustrating an electrode unit and a current collecting structure of a conventional non-aqueous secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Top lid 2 Bottom container 3 Positive electrode terminal 4 Negative terminal 5 Injection port 6 Sealing film 101a Positive electrode (both surfaces) 101b Negative electrode (both surfaces) 101c Negative electrode (one surface) 105a Positive current collector 105b Negative current collector 106a Positive current collector 106b Negative electrode Current collecting piece 107a Positive electrode positioning hole 107b Negative electrode positioning hole

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01M 4/48 H01M 4/48 4/58 4/58 (72) Inventor Shizukuni Yada Hirano-cho, Chuo-ku, Osaka-shi, Osaka 4-1-2, Kansai New Technology Research Institute Co., Ltd. (72) Inventor Haruo Kikuta 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka Gas Co., Ltd. 5H011 AA01 AA09 AA13 CC06 DD13 KK01 5H022 AA09 AA18 CC08 CC12 CC16 5H029 AJ07 AJ12 AJ14 AK03 AL02 AL06 AL07 AL16 AM00 AM03 AM04 AM05 AM07 AM16 BJ03 BJ12 BJ14 BJ15 DJ02 DJ05 HJ04 HJ12 HJ19 5H050 AA13 AA14 AA19 CA07 CB07 CA17 CB

Claims (9)

[Claims] A non-aqueous electrolyte containing a positive electrode, a negative electrode, a separator, and a lithium salt is accommodated in a battery container and has a thickness of 1%.
Flat shape less than 2mm, energy capacity 30W
h and a volume energy density of 180 Wh / l or more, wherein the band-shaped positive electrode and the band-shaped negative electrode are wound in a combined state, and a separator is provided between the positive electrode and the negative electrode. A non-aqueous secondary battery characterized by interposing. 2. A non-aqueous electrolyte containing a positive electrode, a negative electrode, a separator, and a lithium salt is accommodated in a battery container and has a thickness of 1%.
Flat shape less than 2mm, energy capacity 30W
And volume energy density than h is a non-aqueous secondary battery of above 180 Wh / l, folded in a zigzag shape in a state where combined and the strip-shaped cathode and a strip-shaped anode, and, between the positive electrode and the negative electrode Non-aqueous secondary battery characterized in that a separator is interposed in the battery. 3. A current collecting piece is formed along one longitudinal side of the positive electrode and the negative electrode.
Or the non-aqueous secondary battery according to any one of 2. 4. The method according to claim 1, wherein the positive electrode current collector and the negative electrode current collector are located on opposite sides, and the separator, the positive electrode current collector and the negative electrode current collector are stacked so as not to overlap with each other. The non-aqueous secondary battery according to claim 1, wherein: 5. The non-aqueous system according to claim 3, wherein the current collecting pieces are pressed into contact with each other to form a voltage collecting contact portion, and the voltage collecting contact portion is connected to a terminal. Rechargeable battery. 6. The non-aqueous secondary battery according to claim 1, wherein the positive electrode mainly comprises a manganese-based oxide. 7. The negative electrode according to claim 1, wherein the negative electrode includes a material capable of doping and undoping lithium.
The non-aqueous secondary battery according to any one of the above. 8. The non-aqueous secondary battery according to claim 1, wherein the flat front and back surfaces are rectangular. 9. The non-aqueous secondary battery according to claim 1, wherein a plate thickness of the battery container is 0.2 mm or more and 1 mm or less.