JP2000208108A - Thin battery bag for notebook type personal computer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To disperse the local heat of a thin battery without causing the short circuit of a circuit to prevent the deterioration of the battery performance by providing a sheet having a volume natural resistance of a specified value or more and a heat conductivity of a specified value or more on the surface. SOLUTION: A sheet-like base material 7 is formed of a laminate material 5 consisting of a sealant layer 3 of modified polypropylene and a metallic layer 4 of aluminum foil and a sheet 2 adhered to the surface of the metallic layer 4 of the laminate material 5 through a silicone adhesive layer 6. The base material 7 is formed into a bag by mutually heat-sealing the sealant layers 3. Although a heating element as integrated circuit is heated to locally raise the temperature when a notebook type personal computer having such a bag is actuated, the heat is easily dispersed by providing the elastic sheet 2 having a volume resistivity of 1010 Ω.cm or more and a heat conductivity of 0.3 W.m-1. deg.C-1 or more on the whole surface of the bag, and the temperature rise is only temporary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin battery bag for a notebook personal computer which houses a power generating element for a thin battery such as a lithium ion secondary battery.

[0002]

2. Description of the Related Art With the recent development of various electronic devices, there is an increasing need for miniaturization and space saving of electronic devices. Flexibility is required. In order to meet such needs, a lithium ion secondary battery using a gel polymer electrolyte is entering a stage of practical use.

FIGS. 9 and 10 show examples of the structure of a lithium ion secondary battery using the gel polymer electrolyte. In the figure, 21 is a positive electrode current collector (aluminum foil), 22 is a positive electrode (a lithium-containing composite oxide such as lithium cobalt oxide), 23 is a separator (polymer electrolyte plasticized with a solvent), and 24 is a negative electrode (charcoal). ) And 25 are negative electrode current collectors (copper foil).
(In this structural example, an aluminum laminated film is used as the storage means 26). 26a is a heat seal portion formed on the outer peripheral portion of the storage means 26, and 27 is an electrode.

In such a lithium ion secondary battery, the power generating element can be made flexible and the danger of liquid leakage is low, so that the power generating element is housed in a thin laminated material as in the above-described structural example. can do. For example, in JP-A-9-7636, a three-layer laminate foil of a polyethylene layer, an aluminum foil layer, and a polyethylene layer is used as a laminate material. When such a laminated thin battery is used in a notebook computer, it is housed below the keyboard of the notebook computer as shown in FIG.

Further, the area of a thin battery used in a notebook personal computer must be increased in order to secure its capacity.

[0006]

However, as shown in FIG. 1, heat generating portions 28 such as an integrated circuit are scattered inside the notebook personal computer. A part of the battery will be located in the vicinity of the heat generating part 28, and that part will be locally heated. The gel polymer electrolyte used in the thin battery has a high temperature dependency, so that even if a part of the thin battery is heated to a high temperature (for example, 80 ° C. or higher), the performance of the battery deteriorates quickly. For example, at room temperature (25 ° C.), the life of the thin battery is extended by about 500 charge / discharge cycles, but at the high temperature (80 ° C. or higher), the life is extended by about 100 charge / discharge cycles or less.

[0007] Therefore, if a metal sheet having good heat conductivity is provided on the surface of the laminate material in order to easily radiate the heat of the thin battery, the metal sheet has good conductivity.
This causes a short circuit. For this reason, a metal sheet cannot be used.

The present invention has been made in view of such circumstances, and a thin type for a notebook personal computer which can prevent the deterioration of the battery performance by dispersing local heat of the thin battery without causing a short circuit of the circuit. The purpose is to provide a bag for a battery.

[0009]

Means for Solving the Problems To achieve the above object,
Therefore, the thin battery bag for a notebook computer of the present invention
To store power generation elements for thin batteries used in personal computers
A volume resistivity of 10 on the surface of the bag.^Ten
Ω · cm or more and thermal conductivity of 0.3 W · m ^-1・ ℃^-1
With the configuration that the above-mentioned sheet body is provided
You.

That is, the thin battery bag for a notebook personal computer of the present invention has a volume resistivity of 10 ¹⁰ Ω · cm or more and a thermal conductivity of 0 on the surface of the bag housing the power generating element for a thin battery. .3W · m ^-1 · ° C ^-1 or more, the sheet body is provided, so that the local heat of the thin battery can be dispersed to prevent the battery performance from deteriorating. No

Next, the present invention will be described in detail.

The thin battery bag for a notebook personal computer according to the present invention has a volume resistivity of at least 10 ¹⁰ Ω · cm and a thermal conductivity of 0.1 μm on the surface of the bag housing the power generating element for a thin battery.
A sheet member having a temperature of 3 W · m ⁻¹ · ° C. ⁻¹ or more is provided. When the volume resistivity is less than 10 ¹⁰ Ω · cm, the insulation property is reduced, and there is a possibility that a short circuit occurs. When the thermal conductivity is less than 0.3 W · m ⁻¹ · ° C. ⁻¹ , the thermal conductivity deteriorates,
It becomes difficult to disperse the local heat of the thin battery.

The thickness of the sheet is 0.03 to 2 mm.
, And preferably in the range of 0.08 to 1 mm. If the thickness of the sheet is less than 0.03 mm, it is easily broken, and if it is more than 2 mm, the thin battery is disadvantageous in terms of thinness, light weight, and flexibility.

Further, as the above-mentioned sheet member, a sheet member made of a material obtained by mixing ceramic with rubber is used. The mixing ratio of the two is set in the range of 50 to 900 parts by weight, preferably 350 to 500 parts by weight, for 100 parts by weight of rubber. When the mixing ratio of the ceramic is less than 50 parts by weight with respect to 100 parts by weight of rubber, the thermal conductivity is reduced (less than 0.3 W · m ⁻¹ · ° C. ⁻¹ ), and when the mixing ratio exceeds 900 parts by weight, the sheet The flexibility is reduced, which is disadvantageous for the flexibility of the thin battery.

As the rubber material, silicone rubber, H-NBR, EPDM and the like are used. In particular, silicone rubber is effective in that it is not necessary to add an adverse effect such as an antioxidant, and also that a large amount of ceramic can be mixed and the thermal conductivity can be easily increased.

As the ceramic material, Si is used.
O ₂ , Al ₂ O ₃ , AlN, MgO and the like are used. In particular, SiO ₂ is effective in that it has good thermal conductivity, and Al ₂ O ₃ is inexpensive in that it is inexpensive.

The above-mentioned thin battery bag is a sheet-like base comprising a laminate comprising a sealant layer and a metal layer and the above-mentioned sheet adhered to the surface of the metal layer of the laminate via an adhesive layer. The sealant layers are formed by heat-sealing the sealant layers to form a bag.

Examples of the material for the sealant layer include polypropylene, polyethylene, polyester, polyacrylonitrile, ethylene vinyl acetate copolymer (EVA),
Polyvinyl alcohol (PVA), modified polypropylene, polyvinyl acetate, polyvinyl acetate and the like are used. Particularly, polypropylene and polyethylene are preferable from the viewpoint of barrier properties and chemical resistance. The thickness is preferably set in the range of 5 to 1000 μm.
When the film thickness is less than 5 μm, the airtightness (embedding of the sealant) of the electrode seal portion and the insulation between the electrode and the metal layer are reduced. It is disadvantageous for sex.

As the material of the metal layer, aluminum, aluminum alloy,
Copper, copper alloy, iron, stainless steel, titanium, titanium alloy and the like are used, and are formed into various forms such as foil. The thickness is preferably set in the range of 5 to 100 μm. When the film thickness is less than 5 μm, pinholes and the like are likely to be generated in the metal layer, and the gas barrier property and the water-shielding property of the laminate material are reduced. Disadvantaged.

When the sheet material is made of a material obtained by mixing ceramic with rubber, the silane coupling to urethane, epoxy, silicone, or rubber may be used as the adhesive for the adhesive layer. A reactive substance such as an agent is used.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show an embodiment of a thin battery bag for a notebook computer according to the present invention. In this embodiment, the notebook personal computer thin battery 1 is composed of a power generating element and a notebook personal computer thin battery bag housing the power generating element. As shown in FIG. Is housed. A silicone rubber having a volume resistivity of at least 10 ¹⁰ Ω · cm and a thermal conductivity of at least 0.3 W · m ⁻¹ · ° C. ^-1 is provided on the entire surface of the thin battery bag for a notebook computer. An elastic sheet body 2 (see FIG. 2) is provided. The size of the notebook personal computer thin battery 1 is about B5 (JIS standard indicating paper size). Other configurations are the same as those of the related art shown in FIGS. 9 and 10.

More specifically, as shown in FIG. 2, the thin battery bag for a notebook personal computer comprises a sealant layer 3 made of modified polypropylene (QF551 manufactured by Mitsui Chemicals, Inc.) and a metal layer 4 made of aluminum foil. The sealant layer 3 is composed of a sheet-like substrate 7 composed of a laminate 5 and the sheet 2 bonded to the surface of the metal layer 4 of the laminate 5 via a silicone-based adhesive layer 6. These are heat-sealed to form a bag.

The sheet 2 is made of a material obtained by mixing 350 parts by weight of SiO ₂ with respect to 100 parts by weight of silicone rubber.

Then, the above-mentioned thin battery 1 for a notebook personal computer
Is stored below the keyboard of the notebook computer, as shown in FIG. 1, a part of the thin battery 1 for the notebook computer is located near the heat generating portion 28 such as an integrated circuit.

In the above configuration, when the notebook personal computer is operated, the heat generating portion 28 such as the integrated circuit generates heat,
A part of the thin battery 1 for the notebook personal computer in the vicinity thereof becomes locally high in temperature. However, the entire surface of the thin battery bag for a notebook computer has a volume resistivity of 10 ¹⁰ Ω · c.
m and a thermal conductivity of not less than 0.3 W · m ⁻¹ · ° C. ⁻¹ and an elastic sheet body 2 (see FIG. 2) containing silicone rubber as a main component. The heat of the thin battery 1 for use is easy to disperse, and the high temperature is temporary, and does not cause a short circuit.

According to the above embodiment, since the heat of the notebook personal computer thin battery 1 is easily dispersed, even if the notebook personal computer thin battery 1 is located in the vicinity of the heat generating portion 28 such as an integrated circuit, The deterioration of performance will not be accelerated,
Life is not shortened.

Next, examples will be described together with comparative examples.

[0029]

Example 1 and Comparative Example 1 FIG.
2 for a thin battery for a notebook computer according to the above embodiment shown in FIG.
This is a thin battery 1 for a notebook computer using a bag. sand
That is, the laminated material 5 of the sheet-like base material 7 has a thickness of 30 μm.
m modified polypropylene sealant layer 3 and thickness 30μ
m of an aluminum foil metal layer 4. Soshi
Then, a silicone-based adhesive layer 6 is interposed on the surface of the metal layer 4.
Then, a sheet body 2 having a thickness of 80 μm is adhered. this
The sheet body 2 is based on 100 parts by weight of silicone rubber.
SiO _TwoOf 350 parts by weight of
You.

Comparative Example 1 is a thin battery 14 for a notebook personal computer (see FIG. 1) using a conventional thin bag for a thin battery, and uses a sheet-like base material 8 shown in FIG. That is, the laminated material 5 of the sheet-shaped base material 8 is the same as the laminated material 5 of the first embodiment, and has a thickness of 30 μm on the surface of the metal layer 4 via the urethane-based adhesive layer 9.
Sheet body 10 is adhered. This sheet body 10
Is made of polyethylene terephthalate.

The following experiment was conducted on the thin battery 1 for a notebook personal computer of Example 1 and Comparative Example 1. That is, first, each of the notebook-type thin batteries 1 and 14 is attached to the notebook-type personal computer, the notebook-type personal computer is operated, and the heat generating unit 28 such as an integrated circuit is heated to generate one of the notebook-type thin-type batteries 1 and 14. The part was locally hot. Then, the notebook computer was used for 10 minutes. In this case, the surface temperature of the power generating element of each of the notebook personal computers 1 and 14 was measured.

As shown in FIGS. 4 and 5, the surface temperature was measured by installing the thermocouple 16 on one side of the surface of the power generating element 15 where the heat generating portion 28 was located. This installation was performed by equally arranging 25 thermocouples 16 so as to be arranged in five rows and five rows. That is, the above-described five vertical columns are referred to as columns A to E, and the horizontal columns are referred to as columns a to e.
Assuming a row, a thermocouple 16 is arranged at the intersection of each row. Further, the heat generating portion 28 is located at a portion corresponding to an intersection between the row B and the row b and an intersection between the row B and the row d.

The temperature condition in which a part of each of the thin batteries 1 and 14 for the notebook personal computer was locally heated was the same in Example 1 and Comparative Example 1, and the results are shown in Table 1 and FIG. It was shown to. The results of the temperature state 10 minutes after that are shown in Table 2 and FIG.
Are shown in Table 3 and FIG. 8, respectively.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

Comparing Tables 1 and 6 with Tables 2 and 7, in the notebook computer thin battery 1 of the first embodiment, the temperature of the locally high temperature portion decreases and the heat is dispersed. You can see that. However, comparing Tables 1 and 6 with Tables 3 and 8, in the notebook computer thin battery 14 of Comparative Example 1, the temperature of the locally high temperature portion further rises, and the overall temperature decreases. You can see that it is higher.

The material components and the like of the sheet 2 are not limited to those in the above embodiment, but may be other.
For example, for 100 parts by weight of silicone rubber, AlN
, 400 parts by weight, 1.5 parts by weight of peroxide, and 20 parts by weight of an additive. Further, H-NBR was used in place of silicone rubber, and 350 parts by weight of Al ₂ O ₃ and 1 part of peroxide were added to 100 parts by weight of H-NBR.
The sheet 2 made of a material obtained by mixing 5 parts by weight and 20 parts by weight of an additive may have a thickness of 300 μm. A sheet 2 made of a material obtained by mixing EPDM in place of silicone rubber and mixing 100 parts by weight of EPDM with 350 parts by weight of Al ₂ O ₃ , 1.5 parts by weight of peroxide, and 20 parts by weight of additives. May be 300 μm in thickness.

In the above-described embodiment, the sheet 2 is provided on the entire surface of the bag housing the power generating element. However, the present invention is not limited to this, and the sheet 2 may be provided on a part of the surface of the bag. Is also good.

In the above-described embodiment, the size of the thin battery 1 for a notebook personal computer is set to about B5. However, the present invention is not limited to this, and A4 (JIS indicating paper size) may be used.
Other sizes such as (standard) may be used.

[0041]

As described above, according to the thin battery bag for a notebook personal computer of the present invention, the surface of the bag housing the power generating element for a thin battery has a volume resistivity of 10 ¹⁰ Ω · cm or more. And, since the sheet body having a thermal conductivity of 0.3 W · m ⁻¹ · ° C. ⁻¹ or more is provided, it is possible to disperse local heat of the thin battery and prevent deterioration of the battery performance, Moreover,
Does not cause a short circuit.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state in which a thin battery for a notebook computer is housed in the notebook computer.

FIG. 2 is a partial cross-sectional view showing a sheet-like base material constituting an embodiment of the thin battery bag for a notebook computer of the present invention.

FIG. 3 is a partial cross-sectional view showing a conventional sheet-like base material.

FIG. 4 is an explanatory sectional view showing an experiment.

FIG. 5 is an explanatory plan view showing the above experiment.

FIG. 6 is a graph showing the results of the above experiment.

FIG. 7 is a graph showing the results of the above experiment.

FIG. 8 is a graph showing the results of the above experiment.

FIG. 9 is a perspective view showing a conventional lithium ion secondary battery.

FIG. 10 is a cross-sectional view illustrating a structural example of a conventional lithium ion secondary battery.

[Explanation of symbols]

 2 sheet body

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H011 AA02 CC02 CC05 CC06 CC09 CC10 DD12 KK00 KK02 5H029 AJ12 AL12 AM00 AM16 BJ22 DJ02 EJ08 EJ12 HJ00 HJ01 HJ20

Claims (3)

[Claims] 1. A bag for accommodating a power generating element for a thin battery used in a notebook personal computer, wherein the surface of the bag has a volume resistivity of 10 ¹⁰ Ω · cm or more and a thermal conductivity of 0.1 Ω · cm. A bag for a thin battery for a notebook personal computer, comprising a sheet body having a temperature of 3 W · m ⁻¹ · ° C. ⁻¹ or more. 2. The thin battery bag for a notebook computer according to claim 1, wherein said sheet is made of a material obtained by mixing ceramic with rubber. 3. The thin battery bag for a notebook personal computer according to claim 2, wherein the material is a mixture of 50 to 900 parts by weight of ceramic with respect to 100 parts by weight of rubber.