JP2002110113A - Electromagnetic wave shielding material and electronic apparatus having display function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic shielding material having an excellent electromagnetic shielding effect. SOLUTION: One or a plurality of flat nonaqueous electrolyte secondary batteries 2 are provided for the electromagnetic shielding material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shielding material and an electronic device equipped with a display function provided with the electromagnetic wave shielding material.

[0002]

2. Description of the Related Art At present, a lithium ion secondary battery provided with a non-aqueous electrolyte has been commercialized as a secondary battery for portable equipment such as a mobile phone. This lithium ion secondary battery uses lithium cobalt oxide (LiC) as a positive electrode active material.
oO ₂ ), a carbon material as a negative electrode active material, an organic solvent in which a lithium salt is dissolved in a non-aqueous electrolyte, and a porous film as a separator. As portable devices have become thinner in recent years, thinning of nonaqueous electrolyte secondary batteries such as lithium ion secondary batteries has been studied.

By the way, the importance of electromagnetic wave countermeasures has been increasing due to the rapid spread of digital devices. Since the operating frequency of CPUs of personal computers has reached 1 GHz or more recently, new electromagnetic wave countermeasures have been proposed to replace current electromagnetic wave countermeasures. A countermeasure is awaited.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic wave shielding material having an excellent electromagnetic wave shielding effect, and an electronic device equipped with a display function provided with the electromagnetic wave shielding material.

[0005]

According to the present invention, there is provided an electromagnetic wave shielding material comprising: a container; an electrode group housed in the container, which is flatly wound with a separator interposed between a positive electrode and a negative electrode; A plurality of thin non-aqueous electrolyte secondary batteries having a non-aqueous electrolyte held by an electrode group are provided, and the plurality of thin non-aqueous electrolyte secondary batteries are such that the winding direction of the electrode group is in the same direction. Is characterized by being arranged in a.

According to such an electromagnetic wave shielding material, it is possible to enhance the electromagnetic wave shielding effect. By arranging the electrode groups so that the winding directions are oriented in the same direction, it is possible to optimize the function and effect between the vicinity of the secondary batteries, to improve the broadband and high magnetic loss characteristics, and to achieve high electromagnetic wave shielding. The effect can be realized. For example, assuming that the electromagnetic wave shielding effect when the number of the secondary batteries constituting the shielding material is 1 is 0.5, two secondary batteries are arranged so that the winding direction of the electrode group is the same. When the electromagnetic wave shielding effect is 3, and the two secondary batteries are arranged so that the winding directions of the electrode groups are different from each other, the electromagnetic wave shielding effect becomes 1.

[0007] In the electromagnetic wave shielding material according to the present invention,
The container of the thin non-aqueous electrolyte secondary battery is formed of a film material having a thickness of 0.5 mm or less including a metal layer and a resin layer, and the non-aqueous electrolyte contains γ-butyrolactone, thereby shielding electromagnetic waves. The effect can be enhanced. Further, since the generation of gas in the secondary battery when the temperature of the shield material rises can be suppressed, the shield material can be prevented from being deformed (such as swelling) when the temperature rises.

A first electronic device with a display function according to the present invention comprises a central processing unit, a display unit, and one or a plurality of thin non-aqueous electrolyte secondary devices disposed on the back of the display unit. And an electromagnetic wave shielding material having a battery, and satisfying the following expression (1).

100 ≦ X / Y ≦ 50,000 (1) In the above equation (1), X is the operating frequency (MHz) of the arithmetic unit of the central processing unit, and Y is the thin non-aqueous electrolyte secondary. This is the capacity (Ah) of the battery.

Here, the capacity (Ah) of the thin non-aqueous electrolyte secondary battery means the theoretical capacity (design capacity) of the thin non-aqueous electrolyte secondary battery.

According to the first display function-equipped electronic device, the effect of electromagnetic waves generated from the electronic device on the human body can be reduced, and noise is less likely to be output to the battery. Can be stabilized.
Further, since the power supply of the electronic device also serves as the electromagnetic wave shielding material, it is not necessary to provide a separate space for electromagnetic wave shielding in the electronic device, and the size of the device can be reduced. Further, by disposing the electromagnetic wave shielding material on the back surface of the display unit, the non-aqueous electrolyte secondary battery can be prevented from being heated by heat generated by the CPU and the data recording unit, and the secondary battery can be prevented from being heated. Since the heat radiation efficiency can be increased, it is possible to suppress the thermal deterioration of the cycle characteristics and the discharge characteristics of the nonaqueous electrolyte secondary battery.

In the first electronic device with a display function according to the present invention, the thin nonaqueous electrolyte secondary battery is formed using a film material having a thickness of 0.5 mm or less including a metal layer and a resin layer. By using a container, an electrode group housed in the container, and a non-aqueous electrolyte held by the electrode group and containing γ-butyrolactone, the electromagnetic wave shielding effect of the electromagnetic wave shielding material is increased. be able to. Further, since the generation of gas in the secondary battery when the temperature of the shield material rises can be suppressed, the shield material can be prevented from being deformed (such as swelling) when the temperature rises.

[0013] A second electronic device with a display function according to the present invention is the electronic device with a display function provided with a display unit, wherein a container and a separator are housed in the container and a separator is interposed between the positive electrode and the negative electrode. And an electrode group wound into a flat shape
A plurality of thin non-aqueous electrolyte secondary batteries having a non-aqueous electrolyte held by the electrode group are provided, and the winding directions of the electrode groups of the plurality of thin non-aqueous electrolyte secondary batteries are aligned in the same direction. The electromagnetic wave shielding material is disposed on the back surface of the display unit.

According to the second electronic device equipped with a display function, it is possible to reduce the effect of the electromagnetic waves generated from the electronic device on the human body. Further, since the power supply of the electronic device also serves as the electromagnetic wave shielding material, it is not necessary to provide a separate space for electromagnetic wave shielding in the electronic device, and the size of the device can be reduced. Further, by disposing the electromagnetic wave shielding material on the back surface of the display unit, the non-aqueous electrolyte secondary battery can be prevented from being heated by heat generated by the CPU and the data recording unit, and the secondary battery can be prevented from being heated. Since the heat radiation efficiency can be increased, it is possible to suppress the thermal deterioration of the cycle characteristics and the discharge characteristics of the nonaqueous electrolyte secondary battery.

In the second electronic device with a display function according to the present invention, the container of the thin nonaqueous electrolyte secondary battery is formed of a film material having a thickness of 0.5 mm or less including a metal layer and a resin layer. In addition, by including γ-butyrolactone in the non-aqueous electrolyte, the electromagnetic wave shielding effect can be enhanced. Further, since the generation of gas in the secondary battery when the temperature of the shield material rises can be suppressed, the shield material can be prevented from being deformed (such as swelling) when the temperature rises.

In the first and second electronic devices with a display function according to the present invention, the occupation area of the electromagnetic wave shielding material on the back surface of the display unit is set to 20% or more and 90% or less, so that the electromagnetic wave shielding material is Can further enhance the electromagnetic wave shielding effect.

In the first and second display function-equipped electronic devices according to the present invention, when the number of thin non-aqueous electrolyte secondary batteries included in the electromagnetic wave shielding material is plural, the thin non-aqueous electrolyte secondary By setting the area of each battery facing the rear surface of the display unit within a range of 0.02 to 0.8 when the area of the rear surface of the display unit is 1, the electromagnetic wave of the electromagnetic wave shielding material is reduced. The shielding effect can be further enhanced.

[0018]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

An example of the electromagnetic wave shielding material according to the present invention will be described below with reference to FIGS.

The electromagnetic wave shielding material 1 is a thin secondary battery such as a thin (flat) non-aqueous electrolyte secondary battery (eg, a thin lithium ion secondary battery, a thin lithium secondary battery, a thin lithium polymer secondary battery). 2 includes three assembled batteries connected in series. The positive electrode lead 3 and the negative electrode lead 4 of each thin secondary battery are connected to a protection circuit 5.

The thin non-aqueous electrolyte secondary battery 2 is shown in FIGS.
As shown in FIG. 3, a separator 8 is provided between the positive electrode 6 and the negative electrode 7.
, A non-aqueous electrolyte held by the electrode group 9, a positive electrode lead 3 connected to the positive electrode 6, and a negative electrode lead 4 connected to the negative electrode 7
And a container 10 formed of a film material processed into a bag shape and sealing the electrode group 9. The tips of the positive electrode lead 3 and the negative electrode lead 4 extend outside the exterior body 10. The thickness X of the film material
Is preferably 0.5 mm or less. Further, in the electromagnetic wave shielding material 1, the winding direction P of the electrode group 9 is in the same direction. Further, the electromagnetic wave shielding material 1
May be used as bare as shown in FIG. 1 described above, but may also be used in a state of being stored in a resin case or the like.

According to the electromagnetic wave shielding material 1 according to the present invention as described above, the winding direction P of the electrode group 9 of the thin nonaqueous electrolyte secondary battery 2 is aligned in the same direction, so that the electromagnetic wave shielding effect is obtained. Can be higher. Further, when the surface having the maximum area of the secondary battery 2 is opposed to the electromagnetic wave generation source, the electromagnetic wave shielding effect can be further enhanced.

Hereinafter, the positive electrode 6, the negative electrode 7, the separator 8, the non-aqueous electrolyte, and the exterior material 10 will be described.

1) Positive Electrode 6 For this positive electrode, for example, a conductive agent and a binder are suspended in an appropriate solvent in a positive electrode active material, and this suspension is applied to a current collector such as an aluminum foil, dried, and pressed. It is produced by this.

The positive electrode active material includes various oxides and sulfides. For example, manganese dioxide (MnO ₂ ),
Lithium manganese composite oxide (eg, LiMn ₂ O ₄ or LiMnO ₂ ), lithium nickel composite oxide (eg, LiNiO ₂ ), lithium cobalt composite oxide (Li
CoO ₂ ), lithium nickel cobalt composite oxide (eg, LiNi _{1 -x} Co _x O ₂ ), lithium manganese cobalt composite oxide (eg, LiMn _x Co _{1 -x} O ₂ ), vanadium oxide (eg, V ₂ O ₅ ) And the like. Also,
Organic materials such as a conductive polymer material and a disulfide-based polymer material are also included. Among the positive electrode active materials, a lithium manganese composite oxide (Li
Mn ₂ O ₄ ), lithium nickel composite oxide (LiNiO)
₂ ), lithium cobalt composite oxide (LiCoO ₂ ), lithium nickel cobalt composite oxide (LiNi _0.8 Co
_0.2 O ₂ ), lithium manganese cobalt composite oxide (Li
_{Mn x Co 1-x O 2} ) , and the like.

Examples of the conductive agent include acetylene black, carbon black, graphite and the like.

Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and fluorine-based rubber.

The mixing ratio of the positive electrode active material, the conductive agent and the binder is preferably in the range of 80 to 95% by weight of the positive electrode active material, 3 to 20% by weight of the conductive agent, and 2 to 7% by weight of the binder. preferable.

2) Negative Electrode 7 The negative electrode is prepared, for example, by suspending a negative electrode active material, a conductive material and a binder in an appropriate solvent, applying the suspension to a metal foil such as a copper foil, and drying.
It is produced by pressing.

Examples of the negative electrode active material include lithium metal, lithium alloy (eg, Li ₄ Ti ₅ O ₁₂ ), metal oxide (eg, amorphous tin oxide,
WO _2, etc. MoO _2), TiS _2, can be mentioned carbonaceous material or the like capable of absorbing and releasing lithium ions. Among them, carbonaceous materials are preferred. The negative electrode containing this carbonaceous material is
Since the charge / discharge efficiency of the negative electrode can be improved and the negative electrode resistance associated with the charge / discharge can be reduced, the cycle life and output characteristics of the nonaqueous electrolyte secondary battery can be significantly improved.

Examples of the carbonaceous material include graphite, isotropic graphite, coke, carbon fiber, spherical carbon, resin fired carbon, and pyrolytic vapor grown carbon. Above all, a carbon fiber made of mesophase pitch as a raw material and a negative electrode containing spherical carbon are preferable because they have high charge efficiency and can improve cycle life. Further, it is preferable that the orientation of the carbon fibers and the graphite crystals of the spherical carbon obtained from the mesophase pitch be radial. Carbon fibers and spherical carbon made from mesophase pitch can be obtained by, for example, using a raw material such as petroleum pitch, coal tar, and resin.
It can be produced by carbonizing by heat treatment at 0 ° C. to 2000 ° C. or graphitizing by heat treatment at 2000 ° C. or more.

The carbonaceous material has a plane distance d ₀₀₂ of (002) plane of graphite crystal obtained from an X-ray diffraction peak of 0.33.
It is preferably in the range of 54 nm to 0.4 nm. The carbonaceous material has a specific surface area of 0.5 m ² / BET method.
g or more. A more preferable range of the specific surface area is 1 m ² / g or more.

Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), ethylene-propylene-diene copolymer (EPDM), and styrene-butadiene rubber (SB).
R), carboxymethyl cellulose (CMC) and the like can be used.

3) Separator 8 As the separator, for example, a nonwoven fabric made of synthetic resin,
Examples thereof include a polyethylene porous film and a polypropylene porous film.

4) Non-aqueous Electrolyte The non-aqueous electrolyte may be a liquid non-aqueous electrolyte prepared by dissolving an electrolyte in a non-aqueous solvent, a gelled non-aqueous solution in which a polymer material is combined with a non-aqueous solvent and an electrolyte. Examples include an electrolyte, a solid nonaqueous electrolyte in which an electrolyte is held in a polymer material, and an inorganic solid electrolyte having lithium ion conductivity. Among them, it is preferable to use a liquid non-aqueous electrolyte due to various characteristics.

As the non-aqueous solvent, known non-aqueous solvents can be used, and cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC);
It is preferable to use a non-aqueous solvent mainly composed of a mixed solvent of a cyclic carbonate and a non-aqueous solvent having a lower viscosity than the cyclic carbonate (hereinafter, a second solvent).

Examples of the second solvent include chain carbonates such as dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate, γ-butyrolactone,
Examples of acetonitrile, methyl propionate, ethyl propionate, cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran, and chain ethers such as dimethoxyethane and diethoxyethane are given.

Particularly, the non-aqueous solvent preferably contains γ-butyrolactone. A non-aqueous electrolyte containing such a non-aqueous solvent can improve lithium ion conductivity and stability in a high-temperature environment. In particular,
EC and BL, EC and PC and BL, EC as non-aqueous solvents
And BL and VC, EC and PC and BL and VC, EC and DE
C, It is desirable to use a mixed solvent of EC, PC and DEC. The abundance ratio of EC in the six kinds of mixed solvents is as follows:
It is preferable that each is in the range of 10 to 50% by volume.

As a non-aqueous solvent, γ-butyrolactone (γ
BL), when using γ-
The volume ratio of butyrolactone (γBL) is preferably set to 50% by volume or more of the whole non-aqueous solvent. Since the non-aqueous electrolyte including such a non-aqueous solvent has high thermal stability, it is possible to suppress abnormal heat generation of the battery and further improve safety. If the volume ratio of γBL is less than 50% by volume, the amount of gas generated at high temperatures increases, and it may be difficult to suppress the swelling of the electromagnetic wave shielding material. Further, when the solvent mixed with γBL is a cyclic carbonate (for example, ethylene carbonate), the volume ratio of the cyclic carbonate is relatively high, so that the solvent viscosity is increased, the conductivity is reduced, and the charge / discharge cycle characteristics are reduced. And the large current discharge characteristics deteriorate. Further, when the volume ratio of γBL exceeds 95% by volume, a reaction between the negative electrode and γBL may occur and charge / discharge cycle characteristics and safety may be reduced. Therefore, the volume ratio of γBL in the non-aqueous solvent is 50%. It is preferred to be within the range of ~ 95% by volume. A more preferable range of the volume ratio of γBL is 55% by volume or more and 75% by volume or less. Within this range, the effect of suppressing gas generation during high-temperature storage becomes higher.

Examples of the electrolyte include an alkali salt, and a lithium salt is particularly preferable. As a lithium salt,
Lithium hexafluorophosphate (LiPF ₆ ), lithium borofluoride (LiBF ₄ ), lithium arsenide hexafluoride (LiA
sF ₆ ), lithium perchlorate (LiClO ₄ ), lithium trifluorometasulfonate (LiCF ₃ SO ₃ ), and the like. In particular, lithium hexafluorophosphate (LiPF
₆ ), lithium borofluoride (LiBF ₄ ) is preferred.

The amount of the electrolyte dissolved in the non-aqueous solvent is preferably 0.5 to 2 mol / L.

5) Container 10 As a film material constituting the container 10, for example,
Metal film, resin film such as thermoplastic resin, composite film including a metal layer and a resin layer (for example, a laminate in which one or both sides of a flexible metal layer are covered with a resin layer such as a thermoplastic resin) Film). Among them, a laminate film is desirable because it is lightweight, has high strength, can prevent moisture from entering from outside, and can further enhance the electromagnetic wave shielding effect.

The metal film can be formed of, for example, aluminum, iron, stainless steel, nickel, or the like.

The resin layer constituting the composite film can be formed, for example, from a thermoplastic resin. Examples of such thermoplastic resins include polyolefins such as polyethylene and polypropylene. The resin layer can be formed from one type of resin or two or more types of resins.

The metal layer of the composite film can be formed of, for example, aluminum, iron, stainless steel, nickel, or the like. The metal layer can be formed from one kind of metal or two or more kinds of metals. Among them,
It is desirable to form from aluminum which can prevent water from entering the inside of the battery.

The container produced by using the composite film is sealed, for example, by heat sealing. For this reason, it is desirable to arrange a thermoplastic resin on the inner surface of the container. The melting point of the thermoplastic resin is preferably 120 ° C. or higher, more preferably 140 ° C. to 250 ° C. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene. In particular, it is desirable to use polypropylene having a melting point of 150 ° C. or higher because the sealing strength of the heat seal portion is increased.

The thickness of the film material is 0.01 mm or more,
It is preferable to set it to 0.5 mm or less. This is due to the following reasons. Film material thickness 0.01
If it is less than mm, the strength of the container may be insufficient. On the other hand, it is not so preferable that the thickness of the film material exceeds 0.5 mm from the viewpoint of reducing the thickness and weight of the secondary battery. A more preferable range of the thickness of the film material is 0.1.
It is not less than 05 mm and not more than 0.3 mm.

The thickness of the secondary battery is 0.1 mm or more and 5 m
m or less. This is due to the following reasons. When the battery thickness is less than 0.1 mm,
The strength of the secondary battery may be insufficient. On the other hand, when the battery thickness exceeds 5 mm, the volume energy density of the secondary battery may decrease. A more preferable range of the battery thickness is 0.5 mm or more and 4.5 mm or less.

In FIGS. 1 to 3 described above, a flat electrode group wound in a flat shape with a separator interposed between the positive electrode and the negative electrode was used. A plurality of stacked flat electrode groups or a flat electrode group bent with a separator interposed between a positive electrode and a negative electrode may be used.

Further, in FIGS. 1 to 3 described above, an example in which the present invention is applied to a thin nonaqueous electrolyte secondary battery having a bag-shaped container has been described. The present invention can be similarly applied to a thin non-aqueous electrolyte secondary battery provided with. The bottomed cylindrical and bottomed square cylindrical containers can be formed from, for example, aluminum, iron, stainless steel, nickel, and the like.

Next, an electronic device equipped with a display function provided with the electromagnetic wave shielding material according to the present invention will be described. FIGS. 4 and 5 show an example of the electronic device equipped with a display function.

A notebook computer 11 as a display function-equipped electronic device includes a first main body (upper casing) 13 having a display unit 12 and a keyboard input unit 14.
And a second main body (lower casing) 15 having a central processing unit (CPU) (not shown), and a hinge 16 connecting the first main body 13 and the second main body 15. The first main body 13 is, as shown in FIG.
2, an electromagnetic wave shielding member 17 disposed on the back surface of the display unit 12, and a housing 18 adjacent to the electromagnetic wave shielding member 17. The display unit 12 can employ, for example, a liquid crystal display (LCD), and incorporates a backlight, a circuit board, and the like (not shown).

The electromagnetic wave shielding member 17 includes two sets of assembled batteries in which three thin (flat) non-aqueous electrolyte secondary batteries 2 are connected in series. The positive electrode 3 and the negative electrode 4 of each secondary battery 2 are:
It is connected to the protection circuit 5. The surface of each secondary battery 2 having the maximum area faces the back surface of the display unit 12.
Further, the winding direction P of the electrode group of each secondary battery is aligned in the same direction. In addition, the second main body 20 includes the above-described keyboard input unit 14 and a central processing unit (CPU).
In addition, a DC-DC converter, a hard disk drive, a PC card slot and the like (not shown) are built in. Further, on the rear side surface of the second main body 20,
An external interface (not shown) for connecting a mouse, a printer, and the like is attached.

According to such an electronic device equipped with a display function, the winding direction P of the electrode group of the secondary battery 2 constituting the electromagnetic wave shielding material 17 is in the same direction, and the maximum of the secondary battery 2 Since the surface having the area faces the back surface of the display device, the electromagnetic wave shielding effect can be enhanced. Further, since the electromagnetic wave shielding member 17 also functions as a power supply of the electronic device, the size of the electronic device can be reduced as compared with the case where the electromagnetic wave shielding member and the power supply are separately provided. further,
By disposing the electromagnetic wave shielding material 17 on the back surface of the display unit 12, the non-aqueous electrolyte secondary battery 2
5 can be prevented from being heated by heat generated by the CPU and the data recording device, and the heat radiation efficiency of the secondary battery 2 can be increased. Thermal deterioration of the discharge characteristics can be suppressed.

It is preferable that the display function-equipped electronic device satisfies the following expression (1).

100 ≦ X / Y ≦ 50,000 (1) In the equation (1), X is the operating frequency (MHz) of the arithmetic unit of the central processing unit, and Y is the thin non-aqueous electrolyte. This is the discharge capacity (Ah) of the secondary battery 2.

When X / Y is less than 100, noise may be output to the battery and the battery characteristics may become unstable. On the other hand, if X / Y exceeds 50,000, a high electromagnetic wave shielding effect may not be obtained in the electromagnetic wave shielding material 17. A more preferred range is 500 ≦ X / Y ≦ 1
0000.

In the display function-equipped electronic device, it is desirable that the occupation area of the electromagnetic wave shielding material 17 on the back surface of the display unit 12 is not less than 20% and not more than 90%.
If the occupied area is out of the above range, the electromagnetic wave shielding material 17
This is because there is a possibility that a high electromagnetic wave shielding effect cannot be obtained. A more preferable range of the occupied area is 2
5% or more and 80% or less.

In the electronic equipment with a display function, the display unit 12 for each thin non-aqueous electrolyte secondary battery is provided.
The area facing the back surface is preferably in the range of 0.02 or more and 0.8 or less when the area of the back surface of the display unit 12 is 1. If the facing area when the back surface area of the display unit is 1 is outside the above range, the electromagnetic wave shielding material 1
This is because there is a possibility that a high electromagnetic wave shielding effect cannot be obtained in No. 7. A more preferable range of the facing area when the back surface area of the display unit is 1 is 0.05 or more,
0.6 or less.

[0060]

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

(Example 1) A positive electrode containing an active material such as a lithium-containing composite oxide and a negative electrode containing a carbonaceous substance that occludes and releases lithium ions are wound into a flat shape with a separator interposed therebetween. Thus, an electrode group was produced. Also, a mixed solvent of ethylene carbonate (EC) and γ-butyrolactone (γBL) (mixing volume ratio of 40:60) was mixed with 1.5 mol / L of lithium tetrafluoroborate (LiBF ₄ ).
L was dissolved to prepare a liquid non-aqueous electrolyte. On the other hand, a thickness of 0.1 mm with both sides of aluminum foil covered with polypropylene
Prepare a laminate film of this, molded this into a bag shape,
It was a container. The flat electrode group was accommodated in this, and heated and pressed.

Next, after vacuum drying is performed on the electrodes in the laminated film bag, the liquid non-aqueous electrolyte is injected, and the positive electrode lead and the negative electrode lead extend outside the laminated film bag. By heat-sealing the opening of the bag, a thin non-aqueous electrolyte secondary battery having the structure shown in FIGS. 2 and 3 having a thickness of 3.6 mm and a theoretical capacity Y of 1 Ah was assembled.

By connecting three of the obtained secondary batteries in series, the secondary batteries are arranged with the winding direction of the electrode group being the same direction, and assembled by connecting the protection circuit to the positive electrode lead and the negative electrode lead. The battery was assembled to obtain an electromagnetic wave shielding material.

A notebook computer having the structure shown in FIG. 4 described above and having an operating frequency X of 1000 (MHz) of the arithmetic unit of the central processing unit is prepared, and the electromagnetic wave shielding material is provided on the back of the display unit. The secondary battery was arranged so that the surface having the maximum area faced the rear surface of the display unit. The occupied area of the electromagnetic wave shielding material on the back surface of the display unit is 20%
Met. When the area of the back surface of the display unit is 1, the facing area of each secondary battery with respect to the back surface of the display unit (in this case, the area of the surface having the maximum area of the secondary battery) is , 0.2.

(Comparative Example 1) The winding direction of the electrode group of the thin non-aqueous electrolyte secondary battery located in the middle of the three thin non-aqueous electrolyte An electromagnetic shielding material having the same configuration as in Example 1 was prepared except that the direction of winding of the battery electrode group was reversed.

Comparative Example 2 One thin non-aqueous electrolyte secondary battery having the same configuration as that of Example 1 was prepared and used as an electromagnetic wave shielding material.

With respect to the electromagnetic wave shielding materials of Example 1 and Comparative Examples 1 and 2, one surface of the electromagnetic wave shielding material was irradiated with an electromagnetic wave of 30 MHz to 1 GHz in an electromagnetic dark room,
300-800MHz transmitted through electromagnetic wave shielding material
Was measured, and the results are shown in Table 1 below. However, in this test, the winding directions of the electrode groups of the three secondary batteries constituting the electromagnetic shielding material of Example 1 and the three secondary batteries constituting the electromagnetic shielding material of Comparative Example 1 The winding direction of the electrode group of the secondary battery located at both ends and the winding direction of the electrode group of the secondary battery constituting the electromagnetic wave shielding material of Comparative Example 2 were made the same.

[0068]

[Table 1]

(Example 2) Except that the value of X / Y was changed as shown in Table 2 below by changing the theoretical capacity Y of the thin non-aqueous electrolyte secondary battery to 0.8 Ah, as described above. A notebook computer having the same configuration as that of the first embodiment was prepared.

(Example 2) Except that the value of X / Y was changed as shown in Table 2 below by changing the theoretical capacity Y of the thin non-aqueous electrolyte secondary battery to 1.5 Ah, as described above. A notebook computer having the same configuration as that of the first embodiment was prepared.

(Example 3) The above-described example was adopted except that the value of X / Y was changed as shown in Table 2 below by changing the theoretical capacity Y of the thin nonaqueous electrolyte secondary battery to 2 Ah. A notebook computer having the same configuration as that of the notebook computer was prepared.

Example 4 The theoretical capacity Y of a thin non-aqueous electrolyte secondary battery was set to 1 Ah, and the operating frequency X was set to 10000.
A notebook computer having the same configuration as in the first embodiment described above was prepared except that the value of X / Y was changed as shown in Table 2 below.

Example 5 The theoretical capacity Y of a thin non-aqueous electrolyte secondary battery was set to 0.1 Ah, and the operating frequency X was set to 500
A notebook computer having the same configuration as in the first embodiment described above was prepared except that the value of X / Y was changed as shown in Table 2 below by changing the value to 0.

(Example 6) By changing the number of the secondary batteries constituting the electromagnetic wave shield to six, except that the area occupied by the electromagnetic wave shield on the back of the display unit is changed as shown in Table 2 below. Prepared a notebook computer having the same configuration as that of the first embodiment.

Embodiment 7 By changing the number of the secondary batteries constituting the electromagnetic wave shield to nine, the area occupied by the electromagnetic wave shield on the back of the display unit is changed as shown in Table 2 below. Prepared a notebook computer having the same configuration as that of the first embodiment.

(Embodiment 8) Except that the area occupied by the electromagnetic wave shield on the back surface of the display unit is changed as shown in Table 2 below by changing the number of secondary batteries constituting the electromagnetic wave shield to twelve. Prepared a notebook computer having the same configuration as that of the first embodiment.

(Embodiment 9) By changing the theoretical capacity Y of the secondary battery constituting the electromagnetic wave shield to 0.5 Ah and changing the number of secondary batteries to 9, the display device for each secondary battery is provided. A notebook computer having the same configuration as in the first embodiment described above was prepared, except that the area facing the rear surface of the unit was changed as shown in Table 2 below.

(Embodiment 10) By changing the theoretical capacity Y of the secondary battery constituting the electromagnetic wave shield to 1.5 Ah and changing the number of the secondary batteries to 6, the display device for each secondary battery is provided. A notebook computer having the same configuration as in the first embodiment described above was prepared, except that the area facing the rear surface of the unit was changed as shown in Table 2 below.

(Embodiment 11) By changing the theoretical capacity Y of the secondary battery constituting the electromagnetic wave shield to 3 Ah and changing the number of the secondary batteries to three, the back surface of the display unit for each secondary battery is changed. A notebook computer having the same configuration as that of the above-described first embodiment was prepared except that the area opposed to was changed as shown in Table 2 below.

Comparative Example 3 A known notebook computer in which an electromagnetic wave shielding material was not mounted and a battery pack of a thin non-aqueous electrolyte secondary battery was built in a second main body (lower casing) was used. Prepared. A ferrite material was disposed on the back surface of the first main body (upper casing) of the notebook computer as an electromagnetic wave shielding material.

For the notebook computers of Examples 1 to 11 and Comparative Example 3, 30 MHz to 1 GHz in an anechoic chamber.
The radiation noise up to z is measured, and the average value of the levels obtained at 300 to 800 MHz is defined as the electromagnetic wave shielding effect. The level obtained in Comparative Example 3 is set to 1 for the electromagnetic wave shielding effect. The results are shown in Table 2 below.

[0082]

[Table 2]

As is clear from Table 2, Examples 1 to 11
It can be seen that the notebook computer equipped with the electromagnetic wave shielding material of the above can enhance the electromagnetic wave shielding effect as compared with Comparative Example 3.

[0084]

As described above in detail, according to the present invention, it is possible to provide an electromagnetic wave shielding material having an improved electromagnetic wave shielding effect and an electronic device equipped with a display function equipped with the electromagnetic wave shielding material.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an electromagnetic wave shielding material according to the present invention.

FIG. 2 is a partially cutaway perspective view showing the thin non-aqueous electrolyte secondary battery of FIG.

FIG. 3 is a sectional view showing the thin non-aqueous electrolyte secondary battery of FIG. 1;

FIG. 4 is a schematic view showing an example of an electronic device with a display function according to the present invention.

FIG. 5 shows a first example included in the display function-equipped electronic device of FIG.
FIG. 2 is an exploded view showing a main body (upper casing) of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electromagnetic wave shielding material, 2 ... Thin non-aqueous electrolyte secondary battery, 3 ... Positive electrode lead, 4 ... Negative electrode lead, 5 ... Protection circuit, 6 ... Positive electrode, 7 ... Negative electrode, 8 ... Separator, 9 ... Electrode group, 10 ... Container: 11: notebook computer, 12: display unit, 13: first main unit, 14: keyboard input unit, 15: second main unit (lower casing) 17: electromagnetic wave shield

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroki Inagaki 1 Toshiba R & D Center, Komukai-shi, Kawasaki-shi, Kanagawa Prefecture (72) Inventor Tomokazu Morita Toshiba Komukai, Koyuki-ku, Kawasaki-shi, Kanagawa No. 1, Toshiba Research & Development Center, Inc. (72) Inventor: Choi Ishii 1 Toshiba, Komukai Toshiba, Koyuki-ku, Kawasaki, Kanagawa Prefecture F-term (reference) 5E321 AA01 GG05 GH10 5H011 AA06 BB03 CC02 CC06 CC10 KK01 5H029 AJ14 AK03 AL06 AM03 AM05 AM07 BJ02 BJ14 DJ02 EJ01 EJ12 HJ04 HJ12 HJ19

Claims (7)

[Claims] 1. A thin type comprising a container, an electrode group housed in the container, and wound in a flat shape with a separator interposed between a positive electrode and a negative electrode, and a non-aqueous electrolyte held by the electrode group. An electromagnetic wave shield comprising a plurality of non-aqueous electrolyte secondary batteries, wherein the plurality of thin non-aqueous electrolyte secondary batteries are arranged so that a winding direction of the electrode group faces in the same direction. Wood. 2. The container according to claim 1, wherein the container is formed of a film material having a thickness of 0.5 mm or less including a metal layer and a resin layer, and the non-aqueous electrolyte contains γ-butyrolactone. Electromagnetic wave shielding material. 3. A central processing unit, a display unit, and an electromagnetic wave shielding material disposed on the back of the display unit and including one or more thin non-aqueous electrolyte secondary batteries, and An electronic device equipped with a display function, characterized by satisfying the expression (1). 100 ≦ X / Y ≦ 50,000 (1) In the equation (1), X is the operating frequency (MHz) of the arithmetic unit of the central processing unit, and Y is the capacity of the thin non-aqueous electrolyte secondary battery. (Ah). 4. The thin non-aqueous electrolyte secondary battery includes a container formed using a film material having a thickness of 0.5 mm or less including a metal layer and a resin layer, and an electrode group housed in the container. The electronic device with a display function according to claim 3, further comprising: a non-aqueous electrolyte held by the electrode group and containing γ-butyrolactone. 5. An electronic device equipped with a display function provided with a display unit, comprising: a container; an electrode group housed in the container, wound in a flat shape with a separator interposed between a positive electrode and a negative electrode; A plurality of thin non-aqueous electrolyte secondary batteries having a non-aqueous electrolyte held by an electrode group are provided, and the winding directions of the electrode groups of the plurality of thin non-aqueous electrolyte secondary batteries are aligned in the same direction. An electronic apparatus equipped with a display function, wherein an electromagnetic wave shielding material is disposed on a back surface of the display unit. 6. The display function-equipped electronic device according to claim 3, wherein an occupied area of the electromagnetic wave shielding material on a rear surface of the display device section is 20% or more and 90% or less. 7. When the number of thin non-aqueous electrolyte secondary batteries included in the electromagnetic wave shielding material is a plurality, the area of each thin non-aqueous electrolyte secondary battery facing the back of the display unit is: When the area of the back surface of the display unit is set to 1, 0.0
6. The display function-equipped electronic device according to claim 3, wherein the value is in a range of 2 or more and 0.8 or less.