JP4594478B2 - Non-aqueous secondary battery - Google Patents

Description

[0001]
BACKGROUND 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]
[Prior art]
In recent years, from the viewpoint of effective use of energy aiming at resource saving and global environmental problems, attention has been focused on home-use distributed storage systems for the storage of late-night power storage and solar power generation, storage systems for electric vehicles, etc. Collecting. For example, Japanese Patent Laid-Open No. 6-86463 proposes a total system that combines electricity, gas cogeneration, fuel cells, storage batteries, and the like supplied from a power plant as a system that can supply energy to energy consumers under optimum conditions. ing. A secondary battery used in such a power storage system requires a large battery having a large capacity, unlike a small secondary battery for portable equipment having an energy capacity of 10 Wh or less. For this reason, in the above power storage system, a plurality of secondary batteries are usually stacked in series and used as an assembled battery having a voltage of 50 to 400 V, for example, and in most cases, lead batteries are used.
[0003]
On the other hand, in the field of small secondary batteries for portable devices, the development of nickel-metal hydride batteries and lithium secondary batteries as new batteries has progressed to meet the needs for small size and high capacity, and has a volumetric energy density of 180 Wh / l or more. Batteries are commercially available. In particular, a lithium ion battery has a possibility of a volume energy density exceeding 350 Wh / l, and reliability such as safety and cycle characteristics is superior to a lithium secondary battery using metallic lithium as a negative electrode. , Has dramatically expanded its market.
[0004]
In response, in the field of large-scale batteries for power storage systems, lithium-ion batteries are targeted as candidates for high-energy density batteries, and development is actively underway by the Lithium Battery Power Storage Technology Research Association (LIBES) and others. .
[0005]
The energy capacity of these large-sized lithium ion batteries is about 100 Wh to 400 Wh, and the volume energy density is 200 to 300 Wh / l, the same level as a small secondary battery for portable devices. The shape is typically a cylindrical shape having a diameter of 50 mm to 70 mm, a length of 250 mm to 450 mm, and a flat prismatic shape such as a square or oblong square having a thickness of 35 mm to 50 mm.
[0006]
As for a thin lithium secondary battery, for example, a film battery (Japanese Patent Laid-Open Nos. 5-159757 and 7-57788, in which a film having a thickness of 1 mm or less obtained by laminating metal and plastic is housed in a thin exterior. And a small prismatic battery having a thickness of about 2 mm to 15 mm (Japanese Patent Laid-Open Nos. 8-195204, 8-138727, 9-213286, etc.) are known. Each of these lithium secondary batteries has a purpose corresponding to the miniaturization and thinning of portable devices. For example, the lithium secondary battery has a thickness of several millimeters that can be stored on the bottom of a portable personal computer and has an area of about JIS A4 size. Although the thin battery which has is also disclosed (Unexamined-Japanese-Patent No. 5-283105), since an energy capacity is 10 Wh or less, a capacity | capacitance is too small as a secondary battery for electrical storage systems.
[0007]
[Problems to be solved by the invention]
In general, in small lithium ion batteries for portable devices, separators are currently often designed to have both the role of preventing short circuits and the role of a fuse that stops electrochemical reactions in the event of an abnormality. In response, separators are required to have various characteristics. Specifically, low resistance to obtain high efficiency, mechanical strength such as puncture strength against surface pressure from electrodes and high tensile strength required for entrainment specifications, shutdown that melts and closes the hole at high temperature Characteristics, shape retention after melting, and the like. Therefore, in a small lithium ion battery having an energy capacity of 5 Ah or less, in most cases, a microporous film having a thickness of 20 to 40 μm mainly composed of polyethylene is used.
[0008]
If a malfunction occurs due to equipment failure or misuse on the part of the user, overcharging, external short-circuiting, or standing in a high-temperature environment causes the battery to heat up, causing the electrolyte to decompose or evaporate internally. Gas is generated. In order to prevent an accident associated with an increase in internal pressure, a safety valve is provided on the lid or bottom of the container. As described above, the separator plays an important role as a further safety mechanism. That is, when the battery internal temperature rises abnormally, the polyethylene separator starts to melt from around 120 ° C., and the reaction is suppressed by closing the pores and increasing the battery internal resistance. ing.
[0009]
However, conventionally used polyethylene separators start to shrink simultaneously with the melting phenomenon that closes the pores at high temperature, and the heat shrinkage at high temperature of 150 ° C. is 10% or more in both the vertical and horizontal directions. There were many cases. For this reason, the area of the separator surface is smaller than the area of the electrode surface, or the separator may be torn at the time of large shrinkage deformation, which may cause a risk of an internal short circuit in which the positive electrode and the negative electrode are in direct contact with each other. Problems such as battery thermal runaway occurred. In particular, such a problem is remarkable in a large battery having an energy capacity of 30 Wh or more.
[0010]
An object of the present invention is to provide a highly safe non-aqueous secondary battery having excellent heat resistance in order to solve the above problems.
[0011]
[Means for Solving the Problems]
To achieve the above object, the present invention is a flat nonaqueous secondary battery comprising a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte containing a lithium salt, and has an energy capacity of 30 Wh or more and a volumetric energy density. 180 Wh / l or more, the vertical and horizontal size of the surface of the separator is about 3% longer than that of the negative electrode, the separator is composed of one or more sheets, and at least one separator is thermal shrinkage rate at 0.99 ° C. is state, and are 3% in either direction along the surface, said separator, cellulose, polyester, polyamide, polyphenylene sulfide-based and fluorine-based resins, and inorganic fibers A non-aqueous secondary battery including at least one selected type is provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a non-aqueous secondary battery according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a plan view and a side view of a flat rectangular (note type) non-aqueous secondary battery for an electricity storage system according to an embodiment of the present invention, and FIG. 2 is a diagram of the battery shown in FIG. It is a side view which shows the structure of the electrode laminated body accommodated in an inside.
[0013]
As shown in FIGS. 1 and 2, the non-aqueous secondary battery of this embodiment includes a battery case (battery container) including an upper lid 1 and a bottom container 2, and a plurality of positive electrodes housed in the battery case. 101 a, negative electrodes 101 b and 101 c, and an electrode laminate including the separator 104. In the case of a flat type non-aqueous secondary battery as in the present embodiment, the positive electrode 101a and the negative electrode 101b (or the negative electrode 101c disposed on both outer sides of the laminate) are provided via a separator 104 as shown in FIG. However, the present invention is not particularly limited to this arrangement, and the number of stacked layers can be variously changed depending on the required capacity.
[0014]
The positive electrode current collector 105 a of each positive electrode 101 a is electrically connected to the positive electrode terminal 3. Similarly, the negative electrode current collector 105 b of each of the negative electrodes 101 b and 101 c is electrically connected to the negative electrode terminal 4. The positive terminal 3 and the negative terminal 4 are attached in a state insulated from the battery case, that is, the upper lid 1. The upper lid 1 and the bottom container 2 are welded by melting the upper lid along the entire circumference at point A shown in the enlarged view of FIG. The upper lid 1 is provided with an electrolytic solution injection port 5. After the electrolytic solution is injected, a thermoplastic film 6 having a low moisture permeability represented by an aluminum-modified polypropylene laminate film and an aluminum-modified polyethylene laminate film. And sealed by heat fusion.
[0015]
In the sealing step, the pressure in the battery is preferably less than atmospheric pressure. Preferably it is 86 kPa or less, More preferably, it is 73 kPa or less. This pressure is determined in consideration of the separator to be used, the type of electrolyte, the material, thickness, shape, etc. of the battery container. When the internal pressure is equal to or higher than atmospheric pressure, the battery becomes larger than the design thickness, resulting in large variations in thickness, which causes variations in the internal resistance and capacity of the battery.
[0016]
The size of the nonaqueous secondary battery shown in FIGS. 1 and 2 is, for example, 300 mm long × 210 mm wide × 6 mm thick, and a lithium secondary using LiMn ₂ O _{4 for} the positive electrode 101a and a carbon material for the negative electrodes 101b and 101c. In the case of a battery, for example, it can be used in a power storage system.
[0017]
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, and lithium composite cobalt oxide, lithium composite nickel oxide, lithium composite manganese oxide, or a mixture thereof, A system in which one or more different metal elements are added to these composite oxides can be used, and a high voltage and high capacity battery can be obtained, which is preferable. Further, when safety is important, manganese oxide having a high thermal decomposition temperature is preferable. As this manganese oxide, a lithium composite manganese oxide typified by LiMn ₂ O ₄ , a system in which one or more different metal elements are added to these composite oxides, and further, lithium, oxygen, etc. are in excess of the stoichiometric ratio. LiMn ₂ O ₄ prepared in the above manner.
[0018]
The negative electrode active material used for the negative electrodes 101b and 101c is not particularly limited as long as it is a lithium-based negative electrode material, and is a material capable of doping and dedoping lithium, such as safety and reliability such as cycle life. Is preferable. Examples of materials that can be doped and dedoped with lithium include graphite-based materials, carbon-based materials, tin oxide-based, silicon oxide-based metal oxides, and polyacene, which are used as negative electrode materials for known lithium ion batteries. Examples thereof include conductive polymers represented by organic organic semiconductors. In particular, from the viewpoint of safety, a polyacene-based substance that generates a small amount of heat at around 150 ° C. or a material containing the same is desirable.
[0019]
As the electrolyte of the non-aqueous secondary battery of this embodiment, a non-aqueous electrolyte containing a known lithium salt can be used, which is appropriately determined according to the use conditions such as the positive electrode material, the negative electrode material, and the charging voltage, and more specifically. Includes lithium salts such as LiPF ₆ , LiBF ₄ , LiClO ₄ , propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, dimethoxyethane, γ-butyl lactone, methyl acetate, methyl formate, or two or more of these The thing etc. which melt | dissolved in organic solvents, such as a mixed solvent, are illustrated. Further, the concentration of the electrolytic solution is not particularly limited, but generally 0.5 mol / l to 2 mol / l is practical, and naturally the electrolytic solution has a water content of 100 ppm or less. It is preferable to use it. In addition, the non-aqueous electrolyte used in this specification means a concept including a non-aqueous electrolyte solution and an organic electrolyte solution, and also refers to a concept including a gel-like or solid electrolyte.
[0020]
Next, the separator 104 will be described in more detail. The structure of the separator 104 is not particularly limited, but a single-layer or multi-layer separator can be used. At least one of the separators preferably has a thermal shrinkage rate of 150 ° C. of 5% or less in any direction along the surface, and more preferably 3% or less. Although the separator depends on the internal structure of the battery, in general, the size in the vertical and horizontal directions of the surface is designed to be about 1 to 3% longer than that of the positive electrode and the negative electrode for the purpose of preventing internal short circuit. For this reason, if the thermal shrinkage rate exceeds 5%, the separator shrinks to a size smaller than the electrode in a heating state at 150 ° C., causing an internal short circuit in which the positive electrode and the negative electrode directly contact around the separator. This is because there is a risk that an internal short circuit may occur at a location where the separator is broken due to large shrinkage deformation. This heat shrinkage rate is calculated from the dimensional change after the separator 104 is heated on a hot plate from 25 ° C. to 150 ° C. and maintained at 150 ° C. for 10 minutes.
[0021]
Examples of the material of the separator 104 having a small heat shrinkage ratio and high heat resistance include cellulose-based, polyester-based, polyamide-based, polyphenylene sulfide-based, fluorine-based, polyolefin-based resins, or inorganic fibers such as glass fibers. Although not particularly limited, it is a cellulose, polyester, polyamide, polyphenylene sulfide and fluorine resin, and at least one selected from inorganic fibers as a main component, cost, water content, It is desirable from the viewpoint of processing. The basis weight of the separator is preferably 5 g / m ² or more and 30 g / m ² or less, more preferably 5 g / m ² or more and 20 g / m ² or less, and further preferably 8 g / m ² or more and 20 g / m ^2. It is as follows. If the basis weight of the separator exceeds 30 g / m ^2, or separator also increased cell thickness by thickening, or not preferred since the internal resistance of the battery becomes high porosity is lowered, 5 g / m ² If it is less than 1, practical strength cannot be obtained, which is not preferable.
[0022]
The non-aqueous secondary battery configured as described above can be used for a household power storage system (night power storage, cogeneration, solar power generation, etc.), a power storage system such as an electric vehicle, and the like. It can have an energy density. In this case, the energy capacity is preferably 30 Wh or more, more preferably 50 Wh or more, and the energy density is preferably 180 Wh / l or more, more preferably 200 Wh / l. When the energy capacity is less than 30 Wh or when the volumetric energy density is less than 180 Wh / l, the capacity is small for use in the power storage system, and it is necessary to increase the number of series-parallel batteries to obtain sufficient system capacity. In addition, it is not preferable for a power storage system because a compact design becomes difficult.
[0023]
By the way, in general, a large lithium secondary battery (energy capacity of 30 Wh or more) for a power storage system can obtain a high energy density, but its battery design is an extension of a small battery for portable devices. However, the shape of the battery is a cylindrical shape, a rectangular shape or the like that is three times or more that of a small battery for portable devices. In this case, heat is likely to be accumulated inside the battery due to Joule heat generation due to the internal resistance of the battery during charging and discharging, or internal heat generation of the battery due to change in entropy of the active material due to the entry and exit of lithium ions. For this reason, the temperature difference between the temperature inside the battery and the vicinity of the battery surface is large, and the internal resistance differs accordingly. As a result, variations in charge amount and voltage are likely to occur. In addition, since this type of battery is used as a plurality of assembled batteries, the ease of heat storage differs depending on the installation position of the batteries in the system, resulting in variations among the batteries, and accurate control of the entire assembled battery is possible. It becomes difficult. In addition, because of insufficient heat dissipation during high-rate charging / discharging, etc., the battery temperature rises, leaving the battery unfavorable, resulting in a decrease in life due to decomposition of the electrolyte, and thermal runaway of the battery. Problems such as induction of reliability, particularly safety, remained.
[0024]
The flat non-aqueous secondary battery according to the present embodiment has a large heat radiation area and is advantageous for heat radiation, and thus can solve the above-described problems. That is, the nonaqueous secondary battery of the present embodiment has a flat shape, and the thickness thereof is preferably less than 12 mm, more preferably less than 10 mm, and further preferably less than 8 mm. As for the lower limit of the thickness, 2 mm or more is practical in consideration of the filling factor of the electrode and the battery size (the area becomes larger in order to obtain the same capacity as the thickness is reduced). When the thickness of the battery is 12 mm or more, it becomes difficult to sufficiently dissipate 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, resulting in different internal resistances. The variation in the amount of charge and voltage in the battery increases. The specific thickness is appropriately determined according to the battery capacity and the energy density, but it is preferable to design with the maximum thickness that provides the expected heat dissipation characteristics.
[0025]
In addition, as the shape of the non-aqueous secondary battery of the present embodiment, for example, the flat front and back surfaces can be various shapes such as a square, a circle, an oval, etc. However, it may be a polygon such as a triangle or a hexagon. Furthermore, it can also be made into cylindrical shapes, such as a thin cylinder. In the case of a cylinder, the thickness of the cylinder is the thickness referred to here. Further, from the viewpoint of ease of manufacture, the flat front and back surfaces of the battery are rectangular, and a notebook shape as shown in FIG. 1 is preferable.
[0026]
The materials used for the top lid 1 and the bottom container 2 that serve as the battery case are appropriately selected depending on the use and shape of the battery, and are not particularly limited, and iron, stainless steel, aluminum, etc. are common and practical. is there. Further, the thickness of the battery case 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 the portion of 80% or more of the battery surface area (the thickness of the portion having the largest area constituting the battery case) is 0.2 mm or more. If the thickness is less than 0.2 mm, it is not desirable because the strength required for manufacturing the battery cannot be obtained. From this viewpoint, it is more preferably 0.3 mm or more. The thickness of the same part is desirably 1 mm or less. If this thickness exceeds 1 mm, the force to hold 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. Preferably it is 0.7 mm or less.
[0027]
As described above, by designing the thickness of the non-aqueous secondary battery to be less than 12 mm, for example, when the battery has a large capacity of 30 Wh or more and a high energy density of 180 Wh / l, a high rate charge / discharge, etc. However, the rise in battery temperature is small, and it can have excellent heat dissipation characteristics. Therefore, the heat storage of the battery due to internal heat generation is reduced, and as a result, it is possible to suppress the thermal runaway of the battery, and it is possible to provide a non-aqueous secondary battery excellent in reliability and safety.
[0028]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
(Example)
(1) 100 parts by weight of LiCo 2 O 4, 8 parts by weight of acetylene black and 3 parts by weight of polyvinylidene fluoride (PVDF) were mixed with 100 parts by weight of N-methylpyrrolidone (NMP) to obtain a positive electrode mixture slurry. The slurry was applied to both sides of a 20 μm thick aluminum foil serving as a current collector, dried, and then pressed to obtain a positive electrode. In this example, the application area (W1 × W2) of the positive electrode 101a is 262.5 × 192 mm ² , and is applied to both surfaces of a 20 μm current collector 105a with a thickness of 103 μm. As a result, the electrode thickness is 226 μm. Moreover, there is an ear portion to which the electrode is not applied on the short side of the electrode, and a mounting hole having a diameter of 3 mm is provided.
[0029]
(2) 100 parts by weight of graphitized mesocarbon microbeads (MCMB, manufactured by Osaka Gas Chemical Co., No. 6-28) and 10 parts by weight of PVDF were mixed with 90 parts by weight of NMP to obtain a negative electrode mixture slurry. The slurry was applied to both sides of a 14 μm thick copper foil serving as a current collector, dried, and then pressed to obtain a negative electrode. The application area (W1 × W2) of the negative electrode 101b or 101c is 267 × 195 mm ² . The negative electrode 101b is applied to both surfaces of the 18 μm current collector 105b with a thickness of 108 μm, and as a result, the electrode thickness is 234 μm. On the short side of the electrode, there is an ear portion to which no electrode is applied, and a 3 mm diameter mounting hole is provided. In addition, the negative electrode 101c was applied to only one surface in the same manner as the negative electrode 101b to form a single-sided electrode having a thickness of 126 μm.
[0030]
(3) The separator 104 (manufactured by Nippon Kogyo Paper Industries Co., Ltd., TF4030), which is a cellulosic resin, as shown in FIG. Thus, an electrode laminate was prepared by alternately laminating. The thermal contraction rate of this separator 104 at 150 ° C. was 1.0 to 1.1%. The single-sided electrode is arranged on the outermost side as indicated by reference numeral 101c.
[0031]
(4) The bottom container 2 of the battery (see FIG. 1) was prepared by drawing a 0.5 mm SUS304 thin plate to a depth of 5 mm. Further, the upper lid 1 of the battery was also made of a thin plate made of SUS304 having a thickness of 0.5 mm. An aluminum positive electrode terminal and copper negative electrode terminals 3 and 4 (diameter 6 mm) were attached to the upper lid 1. The positive and negative terminals 3 and 4 are insulated from the upper lid 1 by a polypropylene gasket.
[0032]
(5) The positive electrode terminal 3 and the negative electrode terminal 4 were inserted into the positive electrode mounting holes and the negative electrode mounting holes, respectively, of the electrode laminate prepared in the above item (3), and bonded with aluminum and copper bolts, respectively. And the electrode laminated body was fixed with the insulating tape, and the corner | angular part A of FIG. 1 was laser-welded over the perimeter. Thereafter, a solution obtained by dissolving LiPF6 at a concentration of 1 mol / l in a solvent in which ethylene carbonate and diethyl carbonate were mixed at a weight ratio of 1: 1 as an electrolytic solution was injected from an electrolytic solution injection hole 5 having a diameter of 6 mm. Subsequently, the electrolyte solution injection hole 5 was sealed by heat fusion under a reduced pressure of 40 kPa with a 0.08 mm thick aluminum foil-modified polypropylene laminate film punched to a diameter of 12 mm.
(6) The battery obtained as described above is charged to 4.1 V with a current of 5 A, and then a constant current and constant voltage charge for applying a constant voltage of 4.1 V is performed for 12 hours, followed by a low current of 5 A. When discharged to 2.5 V, the discharge capacity was 23.5 Ah, and the energy capacity was 85 Wh. After confirming the capacity, the same charging as described above was performed again to obtain the end-of-charge state. Next, in order to confirm safety, a heating test up to 150 ° C. was performed according to UL1642. Even when the battery surface temperature was 150 ° C. or higher, the battery voltage did not drop, and the heat resistance and safety were good.
[0033]
(Comparative example)
A battery made of a polyethylene resin (N710, manufactured by Asahi Kasei Kogyo Co., Ltd.) was used in place of the separator used in the above example, and a battery was manufactured in the same manner as in the above example.
This battery was charged to 4.1 V with a current of 5 A, then subjected to constant current and constant voltage charging to which a constant voltage of 4.1 V was applied, and then discharged to 2.5 V with a low current of 5 A. The capacity was 23.4 Ah and the energy capacity was 84 Wh. After confirming the capacity, the same charging as described above was performed again to obtain the end-of-charge state. Next, in order to confirm safety, a heating test up to 150 ° C. was performed according to UL1642. When the battery surface temperature reached 130 ° C. or higher, the battery voltage dropped rapidly, and the battery surface temperature rose above the heating atmosphere temperature, so the test was stopped. After the test, an internal short circuit due to shrinkage of the separator was confirmed.
[0034]
【The invention's effect】
As is apparent from the above description, according to the present invention, a flat battery, particularly a flat battery having a large capacity and a high volume energy density, can be used by using a separator having a low thermal shrinkage even in a high temperature environment. In addition, it is possible to provide a highly safe non-aqueous secondary battery that prevents internal short circuit and has excellent heat resistance.
[Brief description of the drawings]
1A and 1B are a plan view and a side view of a nonaqueous secondary battery for a power storage system according to an embodiment of the present invention.
2 is a side view showing a configuration of an electrode laminate housed in the battery shown in FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Top cover 2 Bottom container 3 Positive electrode terminal 4 Negative electrode terminal 5 Injection hole 6 Sealing film 101a Positive electrode (both sides)
101b Negative electrode (both sides)
101c Negative electrode (single side)
104 Separator 105a Positive electrode current collector 105b Negative electrode current collector

Claims (6)

A flat non-aqueous secondary battery comprising a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt,
The energy capacity is 30 Wh or more and the volume energy density is 180 Wh / l or more,
The vertical and horizontal size of the separator surface is about 3% longer than that of the negative electrode,
The separator is composed of one or more sheets,
At least one of said separator, thermal shrinkage at 0.99 ° C., Ri der 3% in either direction along the surface,
The non-aqueous secondary battery , wherein the separator includes at least one selected from cellulose-based, polyester-based, polyamide-based, polyphenylene sulfide-based and fluorine-based resins, and inorganic fibers . A flat non-aqueous secondary battery including a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt,
The energy capacity is 30 Wh or more and the volume energy density is 180 Wh / l or more,
The vertical and horizontal sizes of the separator surface are about 3% longer than that of the negative electrode,
The separator is composed of one or more sheets,
At least one of the separators has a thermal shrinkage rate at 150 ° C. of 1.1% or less in any of the directions along the surface,
The non-aqueous secondary battery, wherein the separator includes at least one selected from cellulose-based, polyester-based, polyamide-based, polyphenylene sulfide-based and fluorine-based resins, and inorganic fibers. The positive electrode, negative electrode and separator are housed in a battery container, the shape of the front and rear surfaces of the battery container, a non-aqueous secondary battery according to claim 1 or 2, characterized in that it is rectangular. The battery container, a non-aqueous secondary battery according to any one of claims 1 to 3 in which thickness is characterized in that it is a flat shape smaller than 12 mm. The nonaqueous secondary battery according to any one of claims 1 to 4 , wherein a thickness of the battery container is 0.2 mm or more and 1 mm or less. 6. The non-aqueous secondary battery according to claim 1, wherein a weight per unit area of the separator is 5 g / m ² or more and 30 g / m ² or less.

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