JP2000067925A - Method and device for manufacturing non-aqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight and safe secondary battery which uses a non-aqueous electrolyte and sustains the use at a high temperature. SOLUTION: This non-aqueous electrolyte secondary battery is provided with a positive and a negative electrode made of substance capable of occluding and releasing lithium ions and is manufactured from a battery precursor accommodated in a battery case made from a laminate film using at least one layer of metal, with a non-aqueous electrolyte being poured into the battery case. The processes for manufacturing include sealing the pour-in hole for precursor, leaving it at a temp. between 35-90 deg.C, opening the precursor, and sealing the pour-in hole again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for manufacturing a non-aqueous electrolyte secondary battery.

[0002]

2. Description of the Related Art In recent years, electronic devices such as a portable radio telephone, a portable personal computer, and a portable video camera have been developed, and various electronic devices have been reduced in size to be portable. Along with this, a battery having a high energy density and a light weight is also adopted as a built-in battery. A typical battery that satisfies such a requirement is an active material such as lithium metal or lithium alloy, or a host material containing lithium ions (here, a host material refers to a material that can occlude and release lithium ions). Lithium intercalation compound occluded in a certain carbon is used as a negative electrode material, and LiC
This is a non-aqueous electrolyte secondary battery using an aprotic organic solvent in which a lithium salt such as 10 ₄ or LiPF ₆ is dissolved as an electrolyte.

This non-aqueous electrolyte secondary battery has a negative electrode plate in which the above-mentioned negative electrode material is held on a negative electrode current collector as a support, and a reversible electrochemical reaction with lithium ions such as a lithium-cobalt composite oxide. The positive electrode plate, which holds the positive electrode active material that reacts on the positive electrode current collector that is the support, from the separator that holds the electrolytic solution and intervenes between the negative electrode plate and the positive electrode plate to prevent a short circuit between the two electrodes Has become.

[0004] The positive electrode plate, the separator and the negative electrode plate are each formed of a thin sheet or foil and sequentially laminated or spirally wound to form a battery made of a metal / resin laminate film having an airtight structure. It is stored in the case. When this nonaqueous electrolyte secondary battery is used in an electronic device, a predetermined voltage is obtained as a single cell or a plurality of cells connected in series. The battery or batteries are
Together with the charge / discharge control circuit, it is stored in a pack made of a resin that is more rigid than the metal / resin laminate film or a composite material of metal and resin.

[0005]

A cell using a battery case formed by heat-sealing a metal / resin laminate film (hereinafter referred to as a laminated cell) is used as a measure against physical impact during use and when handling a battery. For convenience,
In many cases, a laminated unit cell is stored in a battery pack and used. Compared to a battery using a conventional metal case, a laminated unit cell is characterized in that the battery case itself easily expands when abnormal heat is generated inside the battery or when the temperature rises abnormally due to external heating. Is different. Therefore, when the battery pack is stored in the battery pack, the battery pack expands and deforms, so that the pack cannot be removed from the device, or there is a problem that the pack is broken and fragments are scattered, thereby damaging the user. The present invention
The present invention has been made in view of the above problems, and has as its object to provide a lightweight, safe and non-aqueous electrolyte secondary battery that can withstand use at high temperatures.

[0006]

In order to achieve the above object, a method for manufacturing a non-aqueous electrolyte secondary battery according to the present invention comprises a positive electrode and a negative electrode which can occlude and release lithium ions, and use these materials as a battery case. In a method for manufacturing a non-aqueous electrolyte secondary battery from a battery precursor obtained by injecting a non-aqueous electrolyte into a battery case while being housed in a battery case, an inlet for the battery precursor is sealed (hereinafter referred to as “sealing”). )), And then leave the battery precursor sealed at the inlet, and then seal it again.

The reason why the injection port is sealed twice in the manufacturing method of the present invention is as follows. In a non-aqueous electrolyte secondary battery using a material capable of occluding and releasing lithium ions such as a carbon material (hereinafter referred to as “carbon material”) as a negative electrode, a thin electrolyte solution on the surface of the carbon material or the like at the first charge It is known that an inert film is formed. This film is considered to be formed by polymerizing the electrolytic solution. Originally, lithium metal, which is reactive with non-aqueous electrolytes such as organic electrolytes, can stably exist at room temperature in it.
It is considered that the coating suppresses an unnecessary reaction between the lithium metal and the electrolyte.

However, such a film, once formed at the time of the first charge, does not grow thereafter. Therefore,
It cannot serve as a sufficient barrier against rapid diffusion of lithium ions at high temperature, and heat generation due to reaction between lithium ions and the electrolyte cannot be suppressed. Alternatively, depending on the temperature at which the battery is placed, a thermal decomposition reaction of the film itself may occur to generate heat. As described above, the expansion of the battery case due to the abnormal heat generation inside the battery or the temperature rise from the outside is due to the gas generated at this time.

Therefore, in the present invention, the battery precursor is once sealed in the state of being injected as described above, and then left to stand. Gas is intentionally generated during the standing, and the generated gas is released to the outside at the time of opening. By resealing after that, the gas having the above-mentioned properties is prevented from being generated after the completion of the battery. This prevents the battery pack from being expanded, deformed, or broken due to the expansion of the battery case. Further, since the generated gas has high flammability, it can be made safer by discharging the gas before use before use.

The battery case is preferably made of a laminate film using at least one metal layer, such as the above-mentioned metal / resin laminate film. This is because such a film is easily deformed due to gas generation due to its flexibility, and the effect of the present invention is easily exerted.

[0011] The leaving is preferably performed at a temperature in the range of 35 to 90 ° C. When the temperature is lower than 35 ° C., both the film and the electrolyte are stable and gas is hardly generated. On the other hand, when the temperature is higher than 90 ° C., the film on the electrode surface may be thermally decomposed or the electrolyte may be deteriorated. It is. The leaving period is preferably 0.5 hours or more. This is because it is considered that gas is not completely generated in less than 0.5 hour. For the purpose of opening and releasing the gas generated after the initial charging as described above, the initial charging is performed before the above-mentioned leaving, that is, immediately before the first sealing or immediately after the first sealing.

[0012] A suitable manufacturing apparatus used in the manufacturing method of the present invention comprises a positive electrode and a negative electrode which can occlude and release lithium ions, and injects a non-aqueous electrolyte into the battery case with these stored in the battery case. In a device for producing a non-aqueous electrolyte secondary battery from the battery precursor thus obtained, a sealing means for sealing the inlet of the battery precursor, an opening means for opening the sealed battery precursor of the inlet, Resealing means for resealing the battery precursor thus completed to complete the battery.

Since the opening means and the resealing means are provided in addition to the sealing means as described above, the injection port is once sealed by the sealing means, and then left alone to intentionally generate gas inside the battery case. And can be sealed again with the generated gas released.

The sealing means and the resealing means are preferably each a heat welding machine. This is because the laminate film includes a resin layer and can be easily sealed by heat welding. The opening means is preferably a cutting machine. This is because it can be opened instantly and the cutting line is finished neatly.

[0015] The manufacturing apparatus may further include a conveying means for conveying the battery precursor from the sealing means to the opening means for a predetermined required time. This is because if the article is conveyed from the opening means to the opening means for a certain period of time, the time from when the injection port is sealed to when it is opened can be kept constant.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, LiPF6 is generally used as a lithium salt dissolved in an electrolytic solution, but it is not limited thereto, and LiClO ₄ , LiB
F ₄ , LiAsF ₆ , LiCF ₃ CO ₂ , LiCF ₃ SO ₃ ,
LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ CF ₂ C
F ₃ ) ₂ , LiN (COCF ₃ ) ₂ and LiN (COCF
A salt such as ₂ CF ₃ ) ₂ or a mixture thereof may be used.

As the solvent for the electrolytic solution, ethylene carbonate and methyl ethyl carbonate are generally used, but are not limited thereto. Propylene carbonate, butylene carbonate, diethyl carbonate, dimethyl carbonate, γ-butyrolactone, Use a polar solvent such as sulfolane, dimethyl sulfoxide, acetonitrile, dimethylformamide, dimethylacetamide, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolan, methyl acetate, or a mixture thereof. May be.

However, the electrolyte used in the battery according to the present invention is not limited to a non-aqueous electrolyte, but may be an organic solid electrolyte such as a lithium ion conductive polymer solid electrolyte or an inorganic solid electrolyte such as perovskite. It is also possible. When the electrolyte is only a non-aqueous electrolyte, a separator must be provided between the electrodes, but when used in combination with a solid electrolyte, the solid electrolyte also functions as a separator.

As a positive electrode material capable of inserting and extracting lithium, LiCo _0.15 Ni _0.82 Al _0.03 O ₂ is widely used, but is not limited thereto. In addition, a composite oxide represented by the composition formula Li _x MO ₂ or Li _y M ₂ O ₄ (where M is a transition metal, 0 ≦ x ≦ 1, 0 ≦ y ≦ 2), and a tunnel-like composite oxide An inorganic compound such as an oxide having vacancies or a metal chalcogenide having a layered structure can be used. Specifically, LiCoO ₂ , LiNiO
₂ , LiMn ₂ O ₄ , Li ₂ Mn ₂ O ₄ , MnO ₂ , Fe
O ₂ , V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , TiS _{2 and the} like can be mentioned. Further, for example, an organic compound such as a conductive polymer such as polyaniline may be used, or an inorganic compound, an organic compound, and the above-mentioned electrolytic solution may be appropriately mixed and used. As a negative electrode material capable of inserting and extracting lithium, graphite is generally used, but is not limited thereto, and any carbon material capable of inserting and extracting lithium may be used.

[0020]

An embodiment of the present invention will be described with reference to the drawings. Hereinafter, a reference example indicates an example that belongs to the technical scope of claim 1 but may not belong to the technical scope of another claim, and a comparative example indicates the technical scope of any claim. Here is an example that does not belong to the range.

Example 1 FIG. 1 is an explanatory view of a non-aqueous electrolyte secondary battery according to the present invention. The nonaqueous electrolyte secondary battery 1 is housed in a battery case 2 in which an electrode group including a positive electrode plate, a negative electrode plate, and a separator is heat-sealed with a nonaqueous electrolytic solution (not shown) to a metal laminated resin film.

The positive electrode plate is a current collector in which a lithium-cobalt composite oxide is held as an active material. The current collector is an aluminum foil having a thickness of 10 μm. The positive electrode plate is
6 parts of polyvinylidene fluoride as a binder and 3 parts of acetylene black as a conductive agent were mixed together with 91 parts of an active material, and N-methylpyrrolidone was added as appropriate to prepare a paste. It was manufactured by coating and drying on both sides.

As the current collector of the negative electrode plate, a copper foil having a thickness of 14 μm was used. The negative electrode plate was prepared by mixing 92 parts of graphite (graphite) as a host substance and 8 parts of polyvinylidene fluoride as a binder on both sides of the current collector, and adding N-methylpyrrolidone as appropriate to prepare a paste. It was manufactured by coating and drying.

The separator is a polyethylene microporous membrane. Further, the electrolyte, the LiPF ₆ 1 mol / l comprising ethylene carbonate: diethyl carbonate = 4: 6
(Volume ratio). The respective dimensions are as follows: the positive electrode plate has a thickness of 180 μm, the width is 49 mm, and the separator has a thickness of 25 μm.
μm, width 53 mm, negative plate 170 μm thick, width 51
mm, which are superposed one on the other, wound around an elliptical core around a rectangular core of polyethylene, and then housed in a battery case 2 for hermetic sealing.

The battery case 2 has a 12 μm PET layer 21 for surface protection on the outermost layer and a 9 μm aluminum foil 22 as a barrier layer thereunder as shown in FIG. Adhesive. Further, it is made of a laminate film having a 100 μm acid-modified polyethylene layer 23 as a heat welding layer thereunder. Here, the acid-modified polyethylene layer 23 serving as a heat welding layer
Used had a softening point of 100 ° C.

Further, as shown in FIG.
50 μm acid-modified PE layer 3 serving as an adhesive layer with metal on metal conductor 31 of copper, aluminum, nickel, etc.
2 and a 70 μm-thick outer surface as an electrolyte barrier layer
(Kuraray's ethylene vinyl alcohol copolymer resin) layer 33 is provided. When these are overlapped and adhered as shown in the figure, good airtightness can be obtained. Here, aluminum was used for the positive electrode lead terminal material and nickel was used for the negative electrode lead terminal material.

Next, a battery was manufactured by the method shown in FIG. First, a battery precursor 10 that apparently becomes the battery 1 when an electrolyte was injected and sealed was prepared. An electrolytic solution was injected from the opening of the battery precursor 10 opposite to the lead terminal 3 of the battery case 2 and charged to 4.1 V at 250 mA without sealing. Next, the open portion was heat-sealed and sealed to form a sealed state. Then, after leaving at 45 ° C. for 1 hour (hereinafter referred to as “manufacturing leaving”), a portion 2b closer to the lead terminal 3 than the portion 2a finally heat-welded.
Then, the package was opened by cutting, and the gas generated in the battery was released to the outside of the battery. Thereafter, this portion was again heat-sealed to seal under reduced pressure under -700 mmHg.
A non-aqueous electrolyte secondary battery 1 was manufactured. Design capacity 550mA
h, 100 cells of this battery were manufactured.

FIG. 4 shows an apparatus for carrying out the above method, in which a bracket 5 capable of inserting a part of the battery precursor 10 on the lead terminal 3 side is attached to a conveyor 4. The battery precursor 10 is conveyed on the conveyor 4 with the lead terminals 3 facing down and inserted into the bracket 5. The electrolyte is injected into the battery precursor 10 from the upper opening. When the battery precursor 10 is transported to the position of the heat welding machine 6, the conveyor 4 is temporarily stopped, and a detection sensor (not shown) detects the battery precursor 10 and the heat welding machine 6
Is operated to thermally weld the upper end of the battery precursor 10. Thereafter, the conveyor 4 is driven again, and the battery precursor 10 is transported to the position of the cutting machine 7. Here, the cutting machine 7 is operated to cut the battery case 2 at a position slightly below the welded portion of the battery precursor 10. Gas released from the battery case 2 is exhausted by a duct. The conveyor 4 is controlled so as to be driven at such a speed that the required time from the completion of the welding of the heat welding machine 6 to the start of the cutting of the cutting machine 7 becomes constant. Subsequently, the battery precursor 10 is transported to the position of the second heat welding machine 8. Then, the upper end of the battery case 2 opened by cutting is heat-sealed again.

Since the gas generated inside the battery case 2 is released at the same time as the cutting by the cutting machine 7, the transport time from the cutting machine 7 to the second heat welding machine 8 may be short.
Rather, it is preferable that the length be short in order to prevent foreign substances from entering and liquid leakage after opening. Therefore, when the battery precursor 10 is transported from the heat welding machine 6 to the second heat welding machine 8 by one conveyor, the heat welding machine 6 and the cutting machine 7 are installed at a fixed interval, and the cutting machine 7 It is good to be adjacent to the second heat welding machine 8.
The 100-cell battery manufactured as described above was a test product, and was sealed and opened manually instead of using the apparatus shown in FIG. The same applies to the following examples and reference examples.

Example 2 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were set at 45 ° C. for 3 hours. did. -Example 3-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving condition after the first sealing was set to 45 hours at 45 ° C.

Example 4 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were changed to 45 ° C. for 10 hours. did. -Example 5-100 cells of a nonaqueous electrolyte secondary battery were manufactured in the same manner as the manufacturing method described in Example 1, except that the production leaving conditions after the first sealing were set to 45 ° C for 24 hours.

Example 6 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were set to 45 hours at 45 ° C. did. -Example 7-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving conditions after the first sealing were set to 45 ° C for 72 hours.

Example 8 100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the first sealing were set to 96 hours at 45 ° C. did. -Example 9-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the initial sealing were set to 45 hours at 120C for 120 hours.

Example 10 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the first sealing were changed to 45 hours at 45 ° C. for 144 hours. did. -Example 11-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were 168 hours at 45 ° C.

Example 12 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were changed to 60 ° C. for 1 hour. did. -Example 13-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as the manufacturing method described in Example 1 except that the production leaving condition after the first sealing was set at 60 ° C for 3 hours.

Example 14 A 100-cell non-aqueous electrolyte secondary battery was produced in the same manner as in the production method described in Example 1, except that the production leaving condition after the first sealing was changed to 60 ° C. for 5 hours. did. -Example 15-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were set to 60 ° C for 10 hours.

Example 16 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were changed to 60 ° C. for 24 hours. did. -Example 17-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving conditions after the first sealing were set to 60 ° C for 48 hours.

Example 18 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were changed to 60 ° C. for 72 hours. did. -Example 19-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1 except that the production leaving conditions after the first sealing were set to 60 ° C for 96 hours.

Example 20 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were changed to 60 ° C. for 120 hours. did. -Example 21-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as the manufacturing method described in Example 1, except that the production leaving conditions after the first sealing were set to 144 hours at 60 ° C.

Example 22 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were 168 hours at 60 ° C. did. -Example 23-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving condition after the first sealing was set to 85 ° C for 1 hour.

Example 24 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving condition after the first sealing was changed to 85 ° C. for 3 hours. did. -Example 25-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as the manufacturing method described in Example 1 except that the production leaving conditions after the first sealing were changed to 85 ° C for 5 hours.

Example 26 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the initial sealing were changed to 85 ° C. for 10 hours. did. -Example 27-100 cells of a nonaqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were set to 85 ° C for 24 hours.

Example 28 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were changed to 85 ° C. for 48 hours. did. -Example 29-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the first sealing were changed to 85 ° C for 72 hours.

Example 30 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were changed to 85 ° C. for 96 hours. did. -Example 31-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving conditions after the first sealing were set to 85 ° C for 120 hours.

Example 32 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the first sealing were changed to 85 ° C. for 144 hours. did. -Example 33-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as the manufacturing method described in Example 1, except that the production leaving condition after the first sealing was 168 hours at 85 ° C.

Reference Example 1 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the initial sealing were changed to 25 ° C. for 1 hour. did. -Reference Example 2-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were changed to 25 hours at 25 ° C for 3 hours.

Reference Example 3 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were changed to 25 ° C. for 5 hours. did. -Reference Example 4-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the first sealing were changed to 25 ° C for 10 hours.

-Reference Example 5-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were set to 25 hours at 25 ° C. did. -Reference Example 6-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving conditions after the initial sealing were set to 25 ° C for 48 hours.

-Reference Example 7- A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were set to 25 hours at 25 ° C. did. -Reference Example 8-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were set to 96 hours at 25 ° C.

Reference Example 9 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were changed to 25 ° C. for 120 hours. did. -Reference Example 10-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving condition after the first sealing was set to 25 hours at 144 hours.

Reference Example 11 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the initial sealing were 168 hours at 25 ° C. did. -Reference Example 12-100 cells of a nonaqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the initial sealing were 100 ° C for 1 hour.

Reference Example 13 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were 100 ° C. for 3 hours. did. -Reference Example 14-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the production leaving condition after the first sealing was set at 100 ° C for 5 hours.

Reference Example 15 A 100-cell non-aqueous electrolyte secondary battery was manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were changed to 100 ° C. for 10 hours. did. -Reference Example 16-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were changed to 100 ° C for 24 hours.

Reference Example 17 A 100-cell non-aqueous electrolyte secondary battery was produced in the same manner as in the production method described in Example 1, except that the production leaving conditions after the initial sealing were changed to 100 ° C. for 48 hours. did. -Reference Example 18-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as the manufacturing method described in Example 1, except that the production leaving condition after the first sealing was set to 100 ° C for 72 hours.

Reference Example 19 A 100-cell non-aqueous electrolyte secondary battery was produced in the same manner as in the production method described in Example 1, except that the production leaving conditions after the first sealing were changed to 100 ° C. for 96 hours. did. Reference Example 20 100 nonaqueous electrolyte secondary batteries were manufactured in the same manner as in the manufacturing method described in Example 1, except that the manufacturing and leaving conditions after the first sealing were changed to 100 ° C. for 120 hours.

Reference Example 21 A 100-cell non-aqueous electrolyte secondary battery was produced in the same manner as in the production method described in Example 1, except that the production leaving condition after the first sealing was changed to 100 ° C. for 144 hours. did. -Reference Example 22-100 cells of a non-aqueous electrolyte secondary battery were manufactured in the same manner as the manufacturing method described in Example 1 except that the manufacturing and leaving conditions after the first sealing were changed to 168 hours at 100 ° C.

These batteries were charged at 500 mA to 4.2 V for 3 hours, and left in a charged state at 85 ° C. for 14 days (hereinafter referred to as “test left”). In addition, 100 cells of the battery of Example 1 which were not opened and resealed after the initial sealing were manufactured, and similarly, up to 4.2 V at 500 mA.
The battery was charged for a time to obtain a comparative example. The battery of this comparative example was similarly left at 85 ° C. for 14 days in a charged state,
The battery swelled with the passage of time, and finally a part of the heat-welded portion was opened. After the test was left, the results of measuring the gas volume in each battery except the battery of the comparative example are shown in FIG. The gas volume was measured by releasing the gas in paraffin and collecting it in a graduated cylinder. Examples 1-3
3 and Reference Examples 1-22, when the volume of gas contained in the batteries before the test was left was measured, it was found that the volume was slightly 0.5 to 0.5.
It was 6 ml. Since the battery emitted gas generated at the time of the first charge, the internal pressure was estimated to be 1 kgf / cm ² because the battery at this time was at room temperature. Therefore, the volume can be considered as a pore volume in the non-aqueous electrolyte secondary battery.

Although the metal / resin film used for the battery case 2 has low mechanical strength, it has a very high pressure resistance of about 4 to 5 kg / cm ^{2 at} room temperature when sealed. When a non-aqueous electrolyte secondary battery is placed in a battery pack, the battery pack has high rigidity, so that even if the battery is left under the above test conditions, the physical change due to temperature rise and gas generation is not volume expansion, Rather, the internal pressure rises. Then, when the above-mentioned gas equivalent to the pore volume whose internal pressure has increased to near the pressure resistance of the battery case 2 is returned to normal pressure, the volume is calculated to be 8 to 12 ml according to Boyle's law. Therefore, in FIG. 5, if the gas volume is 8 to 12 ml or less, it is considered that there is no danger of liquid leakage and the like even when the battery is left at high temperature during use without opening due to the increase in internal pressure. . And, as shown in FIG.
It is 2 ml or less when the production leaving condition after the initial sealing is 45 to 85 ° C. for 1 to 168 hours (7 days). Therefore, in the present invention, it is preferable to leave the container between the time of first sealing and the time of opening within the range including the production leaving condition.

[0059]

According to the present invention, generation of gas in the battery can be suppressed even when the battery is left at a high temperature or used in a high temperature range, thereby preventing the internal pressure of the battery from increasing. Can be suppressed. For this reason, in a nonaqueous electrolyte battery, the battery can be made light and safe without rupture or leakage of the battery contents at high temperatures.

[Brief description of the drawings]

FIG. 1 is a plan view of a battery according to an example.

FIG. 2 is an XY cross-sectional view of FIG.

FIG. 3 is a diagram illustrating a manufacturing process of the battery of the example.

FIG. 4 is a cross-sectional view showing each step of the battery manufacturing apparatus according to the embodiment.

FIG. 5 is a view showing a gas volume generated in the battery when the battery of the example was left as a test at 85 ° C. for 14 days.

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Claims (9)

[Claims] 1. A non-aqueous electrolyte is prepared from a battery precursor obtained by injecting a non-aqueous electrolyte into a battery case in a state in which the materials capable of occluding and releasing lithium ions are stored as positive and negative electrodes and stored in the battery case. In the method for manufacturing a secondary battery, the non-aqueous electrolyte secondary, characterized in that the inlet of the battery precursor is sealed and then left, and then the sealed battery precursor of the inlet is opened and sealed again. Battery manufacturing method. 2. The method for producing a non-aqueous electrolyte secondary battery according to claim 1, wherein the battery case is formed of a laminated film using at least one layer of metal. 3. The method for producing a non-aqueous electrolyte secondary battery according to claim 1, wherein the leaving is performed at a temperature in the range of 35 to 90 ° C. 4. The method for producing a non-aqueous electrolyte secondary battery according to claim 1, wherein said leaving period is at least 0.5 hour. 5. The method for producing a non-aqueous electrolyte secondary battery according to claim 1, wherein the non-aqueous electrolyte secondary battery is charged first before being left. 6. A battery precursor obtained by injecting a non-aqueous electrolyte into a battery case with the positive and negative materials capable of occluding and releasing lithium ions being contained in the battery case, In an apparatus for manufacturing a secondary battery, sealing means for sealing an inlet of the battery precursor, opening means for opening a sealed battery precursor of an injection port, and sealing the opened battery precursor again as a battery An apparatus for manufacturing a non-aqueous electrolyte secondary battery, comprising: a completed resealing means. 7. The non-aqueous electrolyte secondary battery manufacturing apparatus according to claim 6, wherein said sealing means and resealing means are each a heat welding machine. 8. The apparatus for manufacturing a non-aqueous electrolyte secondary battery according to claim 6, wherein said opening means is a cutting machine. 9. The apparatus for producing a non-aqueous electrolyte secondary battery according to claim 6, further comprising a transporting means for transporting the battery precursor from the sealing means to the opening means for a predetermined required time.