JPH11233075A - Nonaqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte battery enabling the size of an eletronic apparatus, etc., to be reduced. SOLUTION: This nonaqueous electrolyte battery 10 is equipped with a battery unit 4 having a positive electrode 6 and a negative electrode 7 confronting each other through a nonaqueous electrolyte medium 5 and a packaging bag 1 for airtightly housing the battery unit 4 therein, and the packaging bag 1 is formed of one sheet of sheet material for winding and sealing the battery unit 4 therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte battery used for portable telephones, notebook personal computers and the like.

[0002]

2. Description of the Related Art In accordance with a demand for miniaturization of electronic equipment, a demand for miniaturization of a battery used as a power supply thereof has been increasing. In order to satisfy such demands for batteries, thinned batteries are being studied. As such batteries, for example, as disclosed in Japanese Patent Application Laid-Open No. 57-115820, an electrode and a non-aqueous electrolyte are used. A non-aqueous electrolyte battery housed in a packaging bag is known. In such a battery, the packaging bag is formed by overlapping two sheet materials and sealing the four sides.

[0003]

However, in the conventional non-aqueous electrolyte battery described above, the ratio of the sealing portion formed along the entire periphery of the packaging bag in the packaging bag is as follows.
It is desirable that the size of the battery be as small as possible from the viewpoint of reducing the size of the battery and, consequently, the size of the electronic device and the like. To do this,
Although it is conceivable to reduce the seal width of the seal portion, the seal width of the seal portion needs to have a certain width from the viewpoint of ensuring the sealing performance. Therefore, there is a limit to reducing the size of the battery by reducing the seal width to a certain width or less.

[0004] The present invention has been made in view of such problems, and an object of the present invention is to provide a nonaqueous electrolyte battery that can reduce the size of electronic devices and the like.

[0005]

In order to solve the above problems, the present invention comprises a battery unit having a positive electrode and a negative electrode facing each other via a non-aqueous electrolyte medium, and a packaging bag containing the battery unit. The nonaqueous electrolyte battery is characterized in that the packaging bag is formed from one sheet material around which the battery unit is wound and sealed. Here, the non-aqueous electrolyte medium refers to a non-aqueous electrolyte or a solid electrolyte containing an electrolyte.

According to the present invention, it is possible to eliminate the seal portions on both sides of the packaging bag among the sealing portions formed conventionally on the entire periphery of the packaging bag, and to reduce the ratio of the total sealing portion in the packaging bag. You.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a non-aqueous electrolyte battery according to the present invention will be described below in detail with reference to the accompanying drawings. In all the drawings, the same or corresponding components are denoted by:
The same reference numerals are used.

FIG. 1 is a front view showing a first embodiment of the nonaqueous electrolyte battery of the present invention.

The non-aqueous electrolyte battery 10 includes a single battery unit including a non-aqueous electrolyte (non-aqueous electrolyte medium) in which an electrolyte (eg, a lithium compound) is dissolved in a non-aqueous solvent (eg, an organic solvent). Are housed in a packaging bag 1 shown in FIG. From the upper part of the packaging bag 1, one end of a first lead wire 2b covered with an insulator 2a at a peripheral edge and one end of a second lead wire 3b covered with an insulator 3a at a peripheral edge respectively extend upward. Electrical connection with the outside.

FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a sectional view taken along the line III-III of FIG. As shown in FIG. 2, a flat battery unit 4 is accommodated in the packaging bag 1.
Is composed of a non-aqueous electrolyte solution 5, a positive electrode plate 6 and a negative electrode plate 7 immersed in the non-aqueous electrolyte solution 5, and a separator 8 disposed between the positive electrode plate 6 and the negative electrode plate 7. Examples of the non-aqueous electrolyte 5 include LiCl in an organic solvent such as propylene carbonate, gamma-butyrolactone, ethylene carbonate, diethyl carbonate, dimethyl carbonate, 1,2-dimethoxyethane, and tetrahydrofuran.
A solution in which a solute composed of a lithium compound such as O ₄ , LiBF ₄ , LiPF ₆ , or LiAsF ₆ is dissolved is preferably used. In addition, the positive electrode plate 6 and the negative electrode plate 7 include a metal base (not shown) made of a metal foil or expanded metal called a current collector, and an active material layer (not shown) formed on the metal base. Consists of In addition, the solid electrolyte 22 may be used as the non-aqueous electrolyte medium. Also in this case, the same effects as those of the non-aqueous electrolyte 5 described above are obtained. In this case, the separator 8 is unnecessary.

Further, one end of the first lead wire 2b is connected to the metal base material of the positive electrode plate 6 by, for example, spot welding or ultrasonic welding, and the other end is packaged as described above. It extends outside the bag 1. One end of the second lead wire 3b is also connected to the metal base material of the negative electrode plate 7 by, for example, spot welding or ultrasonic welding, and the other end is provided outside the packaging bag 1 as described above. Extending. In addition, from the viewpoint of suppressing the deposition of lithium during overcharge and the formation of a lithium alloy during overdischarge, the first lead wire 2b connected to the positive electrode plate 6 does not dissolve during discharge, for example, aluminum or titanium. Alternatively, a material made of these alloys is used, and the second lead wire 3b connected to the negative electrode plate 7 has precipitates generated during overcharge, or hardly forms an alloy during overdischarge with a large potential difference, and A material that is difficult to dissolve, for example, one made of nickel, copper, or an alloy thereof is used.

The packaging bag 1 is made of a metal foil or metal layer 12 made of, for example, aluminum.
4 is made from one multilayer sheet material formed by sandwiching. This multilayer sheet material is, for example, rectangular. Plastic layer 1 provided inside packaging bag 1
For example, maleic acid-modified polyolefin (for example, maleic acid-modified polyethylene) is used as 3, and for plastic layer 14, for example, PET (polyethylene terephthalate) is used.

The packaging bag 1 includes a first sealing portion 18 that seals the short side edges of one rectangular multilayer sheet material wound around the flat battery unit 4, The second seal portion 16 which seals one of two open ends formed in the multilayer sheet material by one seal portion 18
And a third sealing the other of the two open ends.
The packaging bag 1 is sealed by the first, second and third seal portions 18, 16 and 17.

More specifically, the first seal portion 18
Extends from the second seal portion 16 to the third seal portion 17, and protrudes from the surface of the packaging bag 1 as shown in FIG. The first seal portion 18 is formed by winding a rectangular multi-layer sheet material, overlapping the short-side edges, and heat-sealing the plastic layers 13a and 13b. In addition, the second sealing portion 16 is mainly formed by overlapping one opening end (long side edge) of the multilayer sheet material and opposing the plastic layers 13c, 1c.
The first lead wire 2b and the second lead wire 3b are covered with insulators 2a, 3a and plastic layers 13
c and 13d are thermally fused (see FIG. 2). on the other hand,
The third seal portion 17 is also formed by overlapping the other open ends of the multilayer sheet material and heat-sealing the plastic layers 13e and 13f (see FIG. 2).

According to the non-aqueous electrolyte battery 10 having such a configuration, the sealing portions on both sides of the packaging bag are removed from the sealing portions provided on the entire periphery of the packaging bag in the past, and the first packaging bag 1 is provided.
Since one sealing portion 18 is provided, the packaging bag 1
The proportion of the whole seal portion, that is, the first, second and third seal portions 18, 16, 17 occupied therein is reduced. As a result,
Compared with a conventional non-aqueous electrolyte battery packaging bag, the volume of a battery storage case (not shown) for storing the non-aqueous electrolyte battery 10 can be reduced, and thus a small-sized electronic device or the like incorporating the battery 10 can be obtained. Can be achieved. Further, the volume energy density of the nonaqueous electrolyte battery 10 can be improved. Further, in order to reduce the ratio of the whole seal portion in the packaging bag 1, it is not necessary to narrow each seal width of the first seal portion 18, the second seal portion 16 and the third seal portion 17. In addition, the sealing property of the packaging bag 1 is sufficiently ensured.

Next, a method for manufacturing the nonaqueous electrolyte battery 10 will be described. First, a method for manufacturing the positive electrode plate 6 will be described.

First, the active material of the positive electrode 6 is dissolved in an appropriate solvent to form a paste, and then applied on a metal base such as an aluminum foil except for the portion where the first lead wire 2b is connected. I do. Thereafter, when the active material is dried and subjected to roller pressing, the positive electrode plate 6 is obtained. Next, the negative electrode plate 7 is manufactured in substantially the same manner as the method of manufacturing the positive electrode plate 6 except that the active material of the negative electrode 7 is applied on a metal base material such as a copper foil.

A microporous separator 8 made of, for example, polypropylene is arranged between the positive electrode plate 6 and the negative electrode plate 7 thus obtained. Next, a first lead wire 2b for a positive electrode plate having a rectangular cross section made of, for example, aluminum and a second lead wire 3b for a negative electrode plate having a rectangular cross section made of, for example, copper are prepared. Then, the insulating layers 2a, 3a cover the peripheral portions of the first and second lead wires 2b, 3b. Thereafter, the metal base material of the positive electrode plate 6 and the negative electrode plate 7 on which the active material is not applied is connected to the first lead wire 2b and the second lead wire 3b by ultrasonic welding, respectively. Thereafter, the non-aqueous electrolyte 5 is injected between the separator 8 and the positive electrode plate 6 and the negative electrode plate 7 to obtain the battery unit 4.

Next, a multilayer sheet material including a layer 13 made of maleic acid-modified polyolefin on the surface and a metal foil or a metal layer 12 inside is prepared, and the multilayer sheet material is cut into a rectangle having an appropriate size. I do. Next, the battery unit 4 to which the first lead 2b and the second lead 3b are connected.
Is wound around the multilayer sheet material with the maleic acid-modified polyolefin layer 13 inside. Then, the edge portions on the short side of the multilayer sheet material are overlapped with each other, and the edge portions 13a and 13b of the inner layer 13 are heat-sealed with a desired sealing width using a sealing machine under a predetermined heating condition. . Thus the first
Is formed. At this time, the multilayer sheet material has a tubular shape.

Then, the insulators of the first lead wire 2b and the second lead wire 3b are sandwiched between the peripheral portions of one of the two open ends formed in the cylindrical multilayer sheet material, thereby forming a seal. When a desired seal width is heat-sealed under a predetermined heating condition using a machine, the second seal portion 16 is formed. Next, the peripheral edges of the other open end of the cylindrical multilayer sheet material are overlapped with each other, and are heat-sealed by a sealing machine to a desired sealing width under a predetermined heating condition. It is formed. Thus, the non-aqueous electrolyte battery 10 is obtained.

Next, a second embodiment of the nonaqueous electrolyte battery of the present invention will be described. The non-aqueous electrolyte battery according to this embodiment is different from the non-aqueous electrolyte battery 1 according to the embodiment in the following points.
Different from 0. That is, as shown in FIG. 4, the battery unit 4 is formed by being spirally wound around the first lead wire 2b and the second lead wire 3b arranged side by side, Further, the battery unit 4 has a concave portion 21 for accommodating the first seal portion 18. Also,
As shown in FIG. 5, the battery unit 4 includes a positive electrode plate 6 and a negative electrode plate 7 facing each other, and a nonaqueous electrolyte medium (for example, a solid electrolyte) 5 interposed therebetween. An insulator 19 is attached to at least one of the negative electrode plates 7.

In this case, the volume of the packaging bag 1 is reduced by the concave portion 21 as compared with the nonaqueous electrolyte battery 10 having no concave portion 21, and as a result, the volume energy density of the battery 20 is further improved. In addition, since the first seal portion 18 can be accommodated in the concave portion 21, the volume of a battery accommodating case (not shown) for accommodating the battery 20 can be further reduced, and, as a result, electronic devices and the like incorporating the battery 20 can be further reduced. The size can be further reduced.

It is to be noted that the present invention is applicable to the above first and second embodiments.
However, the present invention is not limited to the embodiment. For example, the battery unit 4 may have the following structure. That is, as shown in FIGS. 6 and 7, the battery unit 4
First and second lead wires 2b, 3b are attached to the tip portions 6a, 7a of the positive electrode plate 6 and the negative electrode plate 7, respectively.
The separators 8a and 8b may be arranged in parallel on both sides of the substrate, and the positive electrode plate 6 and the negative electrode plate 7 may be spirally wound. In addition, such a battery unit 4 is
As shown in FIG. 6, the positive electrode plate 6 is extended straight, separators 8a and 8b are arranged in parallel on both sides thereof, and then the negative electrode plate 7 is shifted so that its tip 7a is shifted from the tip 6a of the positive electrode plate 6. After the separators 8a and 8b and the tip 6a of the positive electrode plate 6 are wound around the tip 7a of the negative electrode plate 7, the positive electrode plate 6 and the negative electrode plate 7 are wound.
In a spiral shape. The battery unit 4 includes a nonaqueous electrolyte 5 between the positive electrode plate 6 and the negative electrode plate 7.
Is impregnated.

Further, the shape of the multilayer sheet material used for producing the packaging bag 1 is not limited to a rectangle. For example, it may be square.

Next, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0026]

EXAMPLES (Example 1) First, a positive electrode plate 6 was produced as follows. First, 100 parts by weight of LiCoO ₂ powder (manufactured by Nippon Chemical Industry Co., Ltd.), 10 parts by weight of graphite and 10 parts by weight of polyvinylidene fluoride were used and mixed as an active material of a positive electrode. Next, a mixture of LiCoO ₂ , graphite and polyvinylidene fluoride was added to N-methyl-
After dissolving in 2-pyrrolidone, it was made into a paste. Then, the paste-like mixture was applied to one surface of an aluminum foil having a thickness of 50 μm except for a portion to which the first lead wire 2b was connected. Thereafter, when the mixture was dried and subjected to roller pressing, the thickness was 0.2 mm and the width was 180 mm.
And a positive electrode plate 6 having a length of 35 mm.

Next, a negative electrode plate 7 was produced. That is, 100 parts by weight of phosphorous natural graphite powder and 20 parts by weight of polyvinylidene fluoride were used and mixed as an active material of a negative electrode. Next, after dissolving in N-methyl-2-pyrrolidone, it was made into a paste. Then, the paste-like mixture was applied to both surfaces of the copper foil having a thickness of 50 μm except for the portion where the second lead wire 3b was connected. Thereafter, the mixture was dried and subjected to roller pressing to obtain a thickness of 0.2 mm and a width of 18 mm.
A negative electrode plate 7 having a length of 0 mm and a length of 35 mm was obtained.

Next, as the first lead wire 2b for the positive electrode plate, a rectangular aluminum conductor having a cross section of 0.1 mm in thickness and 3 mm in width was prepared. The second lead wire 3b for the negative electrode has a thickness of 0.1 mm and a width of 3 m.
A rectangular copper conductor having a cross section of m was prepared. Then, the periphery of the first lead wire 2b and the second lead wire 3b was covered with an insulating layer composed of an inner layer and an outer layer.
Maleic acid-modified polyethylene was used as the inner layer, and an ethylene-vinyl alcohol copolymer was used as the outer layer. Thereafter, the aluminum foil of the positive electrode plate 6 on which the active material was not applied was connected to the first lead wire 2b by ultrasonic welding. The copper foil of the negative electrode plate 7 on which the active material was not applied was connected to the second lead wire 3b by ultrasonic welding.

The positive electrode plate 6 thus obtained is straightened, and microporous separators 8a and 8b made of polypropylene are arranged on both sides thereof in parallel. Then, the negative electrode plate 7 is placed as shown in FIG. The tip 7a was arranged in parallel with the tip 6a of the positive electrode plate 6 so as to be shifted. Each separator 8a, 8b had a thickness of 30 μm.

Further, after the separators 8a, 8b and the tip 6a of the positive electrode plate 6 are wound around the tip 7a of the negative electrode plate 7, as shown in FIG.
Was spirally wound to obtain an electrode unit having a thickness of 4.8 mm, a width of 29 mm, and a length of 35 mm.

Thereafter, the battery unit 4 was obtained by impregnating the electrode unit with 2 cc of a non-aqueous electrolyte. As the non-aqueous electrolyte, a solution prepared by dissolving lithium hexafluorophosphate at a concentration of 1 mol / l in a solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1 was used.

Next, a packaging bag 1 was prepared. First, maleic acid-modified polyethylene, aluminum foil and PET (polyethylene terephthalate) were each 25 μm thick,
A multi-layered sheet material having a thickness of 25 μm and 100 μm was prepared and cut into a rectangle having a length of 80 mm and a width of 50 mm. Next, a multilayer sheet material was wound around the battery unit 4 to which the first lead wire 2b and the second lead wire 3b were connected, with the maleic acid-modified polyethylene layer inside. Then, the opposing edge portions 13a and 13b of the inner layer of the multilayer sheet material are overlapped with each other, and heat-sealed by heating at 200 ° C. for 5 seconds using a sealing machine, thereby forming a first sealing portion 18 having a sealing width of 5 mm. Was formed.

The insulators of the first lead wire 2b and the second lead wire 3b are sandwiched between the peripheral edges of one of the two open ends of the cylindrical multilayer sheet material thus formed, Using a sealing machine, the outer layer of the insulator of the first lead wire 2b and the second lead wire 3b and the inner layer of the peripheral portion of the packaging bag 1 are heated at 200 ° C. for 5 seconds to perform heat fusion, A second seal portion 16 having a seal width of 4 mm was formed.
Then, the peripheral edge portions of the other open ends of the cylindrical multilayer sheet material are overlapped with each other, and heat sealing is performed by heating at 200 ° C. for 5 seconds using a sealing machine. Was formed. Thus, a thickness of 5.3 mm and a width of 30
A non-aqueous electrolyte battery having a length of 48 mm and a length of 48 mm was obtained.

The battery was rated at a capacity of 400 mAh and a voltage of 3.6 V. The volume required for incorporating this battery was 7.6 cm ³ , and the volume energy density when this was occupied was 189 Wh / l.

(Example 2) The battery unit 4 obtained in Example 1 was fixed on a flat surface.
As shown in FIG. 8A, 3 kgf / cm ² over a width of 5 mm between the first lead wire 2b and the second lead wire 3b.
To a depth of 0.3 mm as shown in FIG.
Was formed. For the battery unit 4 thus obtained, a packaging bag 1 was produced in the same manner as in Example 1,
A non-aqueous electrolyte battery having a thickness of 5.0 mm, a width of 30 mm, and a length of 48 mm was obtained.

The battery was rated at a capacity of 400 mAh and a voltage of 3.6 V. The volume required for incorporating this battery was 7.2 cm ³ , and the volume energy density when this was occupied was 200 Wh / l.

(Comparative Example 1) The battery unit 4 is the same as that of the first embodiment.
It was produced in the same manner as described above. The packaging bag 1 was produced as follows.

That is, maleic acid-modified polyethylene,
Two sheets of a multilayer sheet material in which aluminum foil and PET (polyethylene terephthalate) were laminated with a thickness of 25 μm, 25 μm, and 100 μm, respectively, were prepared, and cut into a rectangle having a length of 45 mm and a width of 50 mm. Next, the multilayer sheet materials were overlapped so that the inner layers of the multilayer sheet materials faced each other. In this state, a rectangular 3
The sides were heated at 200 ° C. for 5 seconds, and heat-sealed so that the seal width became 4 mm, to obtain a bag-shaped multilayer sheet material. Next, the battery unit 4 to which the first lead wire 2b and the second lead wire 3b are connected is inserted through the opening of the bag-shaped multilayer sheet material, and the first peripheral portion of the opening forms the first edge.
The insulator of the lead wire 2b and the second lead wire 3b is sandwiched between the first lead wire 2b and the second lead wire 2b.
The outer layer of the insulator of the lead wire 3b and the inner layer at the periphery of the opening of the packaging bag were heated at 200 ° C. for 5 seconds to perform heat fusion to form a seal portion having a seal width of 4 mm. Thus,
A non-aqueous electrolyte battery having a thickness of 5 mm, a width of 40 mm, and a length of 48 mm was obtained.

The battery was rated at a capacity of 400 mAh and a voltage of 3.6 V. The volume required for incorporating this battery was 9.6 cm ³ , and the volume energy density when this was occupied was 150 Wh / l.

[0040]

As described above, according to the present invention, the ratio of the entire sealing portion in the packaging bag is reduced. As a result, when the battery is housed in a battery housing case or the like, the volume of the case can be reduced, and the size of electronic equipment or the like incorporating the battery can be reduced, and the volume energy density of the nonaqueous electrolyte battery can be reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of a nonaqueous electrolyte battery according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a cross-sectional view schematically showing a second embodiment of the nonaqueous electrolyte battery according to the present invention.

FIG. 5 is a sectional view showing a modification of the battery unit.

FIG. 6 is a cross-sectional view showing an electrode unit before being spirally wound in another modified example of the battery unit.

FIG. 7 is a cross-sectional view showing a spirally wound electrode unit.

FIG. 8A is a schematic plan view of a battery unit according to Example 1, and FIG. 8B is a schematic plan view of a battery unit according to Example 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Packaging bag, 4 ... Battery unit, 5 ... Non-aqueous electrolyte (non-aqueous electrolyte medium), 6 ... Positive electrode plate (positive electrode), 7 ... Negative electrode plate (negative electrode), 16 ... Second seal part, 17 ... No. 3, seal part,
18: first seal portion, 21: concave portion, 22: solid electrolyte (non-aqueous electrolyte medium), 30: concave portion.

Claims (4)

[Claims] 1. A non-aqueous electrolyte battery comprising: a battery unit having a positive electrode and a negative electrode opposed to each other with a non-aqueous electrolyte medium interposed therebetween; and a packaging bag that hermetically accommodates the battery unit. A non-aqueous electrolyte battery formed of a single sheet material around which a sheet is wound. 2. The packaging bag according to claim 1, further comprising: a first sealing portion that seals edges of the wound sheet material;
A second seal portion sealing one of the two open ends formed in the sheet material by the seal portion;
A third sealing the other of the two open ends;
The non-aqueous electrolyte battery according to claim 1, further comprising a sealing portion. 3. A recess for accommodating the first seal portion,
The non-aqueous electrolyte battery according to claim 1, wherein the non-aqueous electrolyte battery is formed in the battery unit. 4. The non-aqueous electrolyte battery according to claim 1, wherein the battery unit is formed by spirally winding the battery unit.