JPH11213966A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light and thin battery case while improving the molding property thereof by forming a case of an outer layer of polychlorotrifluoroethylene and an inner layer of the sealant having heat sealing property, and performing Al deposition after the molding, and setting thickness of the Al deposition layer in a specified range. SOLUTION: A battery is formed of a case 5 for sealing a positive and a negative electrodes and the electrolyte filled in a battery as battery structural material and a cover material 4, and the case 5 is formed of an outer layer of polychlorotrifluoroethylene 1 and an inner layer 2 of the sealant having heat sealing property. Al deposition is performed after the molding, and thickness of an Al deposition layer 3 is set at 0.1-5 μm. In this case, as for barrier performance after leaving it for 168 hours at 60 deg.C, a reduction rate of electrolyte is 0.5% or less, increase ratio of the moisture into a system is set at 10 ppm or less, thickness of polychlorotrifluoroethylene 1 is set at 15-100 μm, bonding strength between the case 5 and the cover material 4 is set at 5 kg/25 mm or more, and the cover material 4 is formed of the same multilayered film with the case 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery component.

[0002]

2. Description of the Related Art In recent years, demand for secondary batteries, including notebook type personal computers, has been increasing. Along with this, there is a growing demand for an improvement in the energy density of the battery, and there is a demand for a lighter and thinner battery case. In addition, diversification of the shape is progressing, and improvement in moldability is expected. BACKGROUND ART A simple case of aluminum is used for a packaging case of a unit cell constituting a conventional battery. However, metal battery cases are heavy and thick. In addition, metal battery cases are hard and difficult to form into various shapes.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery using a battery case which is lightweight, thin and has improved moldability, instead of a single metal battery case.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a battery comprising a positive electrode and a negative electrode which are constituent materials of a battery, a case for enclosing an electrolyte injected therein, and a lid material, wherein the case has an outer layer of polychlorotrichloride. The battery is a fluoroethylene, in which the inner layer is made of a sealant having a heat sealing property, Al is deposited after molding, and the thickness of the Al deposited layer is 0.1 to 5 μm.
More preferably, the barrier property of the battery case, after standing at 60 ° C. for 168 hours, the electrolyte reduction rate is 0.5% or less, and the water increase rate in the system is 10 ppm or less, and polychlorotrifluoroethylene is used. The battery has a thickness of 15 to 100 μm, an adhesive strength between the case and the lid material of 5 kg / 25 mm or more, and the lid material is the same multilayer film as the case.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The thickness of an Al vapor-deposited layer used in the present invention is from 0.1 to 5 μm, more preferably from 1 to 2 μm. When the thickness is less than 0.1 μm, pinholes are generated in the Al vapor-deposited layer. If the thickness exceeds 5 μm, it becomes difficult to deposit. The barrier property of the battery case used in the present invention is 60 ° C.
-After standing for 168 hours, the rate of decrease in the electrolyte is 0.5% or less, and the rate of increase in water in the system is 10 ppm or less. If the rate of decrease in the electrolyte exceeds 0.5%, the battery capacity is reduced and reliability is reduced. If the rate of increase in water exceeds 10 ppm, Li ions and water combine to deteriorate charge / discharge characteristics. The thickness of the polychlorotrifluoroethylene used in the present invention is 15 to 100 μm, more preferably 20 to 50 μm. If the thickness is less than 15 μm, molding becomes difficult. When the thickness exceeds 100 μm, the thickness of the multilayer film becomes larger than 200 μm, which is equivalent to the thickness of the conventional single metal case, and the advantages of the present invention are not obtained. The adhesive strength between the case and the lid material used in the present invention is 5k
gf / 25mm or more. If the adhesive strength is less than 5 kgf / 25 mm, the case is destroyed by the internal pressure, and there is a danger of liquid leakage.

[0006]

The present invention will be described in the following examples, which are merely illustrative and not restrictive. The multilayer film shown in FIG. 1 was formed by a dry lamination method, formed by cold forming, subjected to Al deposition, sealed with a multilayer film sheet of the same type, and obtained the battery case shown in FIG. . The weight of the obtained battery case was measured, 2.6 to 2.8 g of the electrolytic solution was put therein, and the rate of decrease in the electrolytic solution and the rate of increase in water after standing at 60 ° C. for 168 hours were measured. Tables 1 and 2 show the battery case configurations and measurement results of Examples and Comparative Examples.
Shown in Note PET: Polyethylene terephthalate PCTFE: Polychlorotrifluoroethylene

Example 1 30 μm thick outer layer film
Using PCTFE, perform Al evaporation of 0.2μm,
Sealing to 6.5 kg / 25 mm was performed. (Example 2) PCTFE having a thickness of 35 µm was used for the outer layer film, Al was deposited to a thickness of 0.5 µm, and a seal having an adhesive strength of 6.5 kg / 25 mm was performed. (Example 3) PCTFE having a thickness of 45 µm was used for the outer layer film, Al was deposited to a thickness of 3.0 µm, and a seal having an adhesive strength of 6.5 kg / 25 mm was performed.

(Comparative Example 1) 30 μm thick outer layer film
Sealing was performed by using PCTFE of which adhesive strength was 6.5 kg / 25 mm. (Comparative Example 2) A 30-μm-thick PET film was used for the outer layer film, and a 0.5-μm-thick Al film was deposited to seal the film so that the adhesive strength was 6.5 kg / 25 mm. (Comparative Example 3) PCTFE having a thickness of 45 µm was used for the outer layer film, Al was deposited to a thickness of 0.01 µm, and a seal having an adhesive strength of 6.5 kg / 25 mm was performed. (Comparative Example 4) PCTFE with a thickness of 10 µm was used for the outer layer film, Al was deposited with a thickness of 0.2 µm, and sealing was performed so that the adhesive strength was 6.5 kg / 25 mm. (Comparative Example 5) PCTFE having a thickness of 30 µm was used for the outer layer film, Al was deposited to a thickness of 0.2 µm, and a seal having an adhesive strength of 1.2 kg / 25 mm was performed.

[0009]

[Table 1]

[0010]

[Table 2]

[0011]

According to the present invention, it is possible to provide a battery using a battery case which is excellent in moisture proofing, lightweight, thin and has improved moldability. Can answer requests.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a layer structure of a multilayer film used in the present invention.

FIG. 2 is a sectional view showing a battery case of the present invention.

[Explanation of symbols]

 1: Polychlorotrifluoroethylene 2: Inner layer (heat sealant layer) 3: Al deposition layer 4: Lid material 5: Case

Claims (2)

[Claims] 1. A battery comprising: a positive / negative electrode which is a battery constituent material; a case for enclosing an electrolyte injected therein; and a lid material, wherein the outer layer is made of polychlorotrifluoroethylene, and the inner layer is made of heat. A battery comprising a sealant having a sealing property, wherein Al is vapor-deposited after molding, and a thickness of an Al-deposited layer is 0.1 to 5 μm. 2. After leaving at 60 ° C. for 168 hours, the rate of decrease of the electrolyte is 0.5% or less and the rate of increase of water in the system is 1%.
2. The battery according to claim 1, wherein the battery is 0 ppm or less, the thickness of the polychlorotrifluoroethylene is 15 to 100 μm, the adhesive strength between the case and the lid material is 5 kg / 25 mm or more, and the lid material is the same multilayer film as the case. .