JPS62281273A - Flat-shaped cell - Google Patents

Abstract

PURPOSE:To prevent external short-circuiting between positive and negative electrode terminal plates by arranging one of positive and negative electrode terminal plates with its edge flush with the edge of an insulating seal plate, and another terminal plate with its edge recessed inward from the edge of the insulating seal plate. CONSTITUTION:In a flat-shaped cell 11, edge 13c of circumference 13a of one of its terminal plates, namely a negative electrode 13 in this case determined in its dimension to be recessed from the edges 14b of circumference 14a of an insulating seal plate 14. It is desirable, in this case that the width d1 of a frame-shaped part 14c along the circumference 14a of a frame-shaped insulating seal plate 14 is made larger than the width d2 of a frame-shaped part along other circumference, because the recessed circumference 13a of the negative electrode terminal plate and the frame-shaped part 14c of the insulating seal plate 14 overlap each other over a sufficient area. On the other hand, edge 12c of circumferece 12a of another terminal plate, namely the positive electrode terminal plate 12, is arranged flush with the edge 14b of the circumference 14a of the insulating seal plate 14. This consitution makes bending of lead section less probable to occur and prevents external short-circuiting.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a flat battery, and more specifically, the present invention relates to a flat battery, in which an external short circuit between positive and negative terminal plates is prevented, and in particular, a card The present invention relates to an a-thin flat battery useful as a power source built into type electronic equipment.

C. Prior Art] In recent years, as electronic devices such as electronic on-board computers and electronic wristwatches have become smaller and thinner, there has been an increasing demand for the development of extremely thin, so-called flat batteries. Among these, ultra-thin batteries with a thickness of 1 mm or less are desired as power sources for card-type electronic devices such as card-type calculators and IC cards.

Such flat batteries generally use a positive electrode mixture.

A power generation unit consisting of a separator and a negative electrode sheet laminated in this order is surrounded by an insulating sealing plate made of, for example, thermofusible young resin, and its upper and lower surfaces are sandwiched between positive and negative terminal plates. When a flat battery having such a structure is loaded into, for example, a card-type electronic device, it is common to connect, for example, band-shaped lead terminals to the positive and negative terminal plates by spot welding or the like. . However, when spot welding lead terminals to the terminal plate, the heat generated causes damage such as melting or deformation of the insulating sealing body, resulting in a problem that the reliability of the battery is significantly reduced.

In order to solve this problem, the applicant has proposed the method shown in FIG. 2 (A).
and proposed a flat battery having the structure shown in (B) (Japanese Patent Application No. 59-247768). That is, in FIG. 2(A), one peripheral edge portion 2a and 3a of the positive terminal plate 2 and negative terminal plate 3 of the flat battery 1 have the following, respectively.
Lead portions 2b and 3b are integrally formed with each terminal plate and extend to have a length of approximately 51 mm. These lead parts 2b and 3b
In order to prevent contact between the two, they are generally formed at positions as far apart as possible from each other as shown in the figure. As shown in FIG. 2 CB), a positive electrode mixture 5, a separator 6, and a negative electrode sheet 7 are placed in the sealed space surrounded by the positive electrode terminal plate 2, the negative electrode terminal plate 3, and the frame-shaped insulating sealing plate 4. A power generation unit made up of stacked layers in this order is housed. When loading such a flat battery into a card-type electronic device, lead terminals (not shown) are connected to the above-mentioned extended lead portions 2b and 3b by spot welding, which may cause thermal damage to the insulating sealing plate 4. This improves battery reliability.

[Problems to be Solved by the Invention] However, since the flat battery 1 itself is thin, the metal terminal plates 2 and 3 used are
is extremely thin, and as a result, the lead portion 2b or 3b is easily bent by a slight external force.For example, if the lead portion 2b of the positive electrode terminal plate 2 is bent,
There is a problem in that this contacts the peripheral edge 3a of the negative terminal plate 3 and causes an external short circuit. In order to avoid such inconvenience, 1. For example, it is possible to shorten the lengths of the lead parts 2b and 3b to prevent bending, but if this is done, the lead terminals will be spot welded to the lead parts. This results in the inconvenience of reduced workability.

The present invention solves this conventional problem, and in a flat battery in which the positive and negative electrode terminal plates each have an extended lead part, when connecting the lead terminal to the lead part by, for example, spot welding, the insulating sealing plate is removed. To provide a flat battery that does not cause thermal damage and does not cause external short circuit between positive and negative terminal plates even if a lead part is bent.

[Means for Solving the Problems] In order to achieve the above object, the inventors of the Wood Inventors conducted intensive research focusing on the shape and dimensions of the positive and negative terminal plates of flat batteries. It has been found that excellent effects can be obtained by arranging a structure in which the end face of the peripheral edge on which the extended lead portion of the terminal board is formed is set back from the end face of the peripheral edge of the insulating sealing plate that follows this peripheral edge. After confirming this, we have completed the present invention.

That is, the flat battery of the present invention includes a laminate in which a positive electrode mixture, a separator, and a negative electrode sheet are laminated in this order; a frame-shaped insulating sealing plate surrounding the laminate; and an entire surface of the positive electrode mixture. and covering one plate surface of the insulating sealing plate,
A flat battery consisting of a positive electrode terminal plate closely laminated to these; and a negative electrode terminal plate closely laminated to these, covering the entire surface of the negative electrode sheet and the other plate surface of the insulating sealing plate. At the peripheral edge of the positive and negative electrode terminal plates along one peripheral edge of the sealing plate, lead portions are formed to extend outward at different positions along one peripheral edge of the insulating sealing plate, and The peripheral edge end face of one of the positive and negative terminal plates, on which the lead portion is formed, is arranged so as to form the same plane as the one peripheral edge end face of the insulating sealing plate along the stacking direction of the terminal plate. , the peripheral edge end face on which the other terminal plate glue portion is formed is arranged so as to be set back inward from the one peripheral edge end face of the insulating sealing plate.

As described above, the flat battery of the present invention includes the peripheral edge end face of one of the positive and negative terminal plates where the extended lead portion is formed, and the peripheral edge of the insulating sealing plate along this peripheral edge. It is characterized by its positional relationship with the end face along the stacking direction, and the constituent materials of each component are not particularly limited.

The basic structure of the flat battery of the present invention is shown below in Figure 1 (A).
The explanation will be based on (C,). Note that the same components as in FIG. 2 are given the same reference numerals. First, Figure 1 (
In the flat battery 11 of the present invention shown in A), the positive terminal plate 12 is located along one peripheral edge 14a of the frame-shaped insulating sealing plate 14.
Lead portions 12b and 13b are formed extending along the peripheral edges 12a and 13a of the negative terminal plate 13 at different positions.

The end face 13c of the peripheral edge 13a of one terminal plate, in this case the negative terminal plate 13, is connected to the edge 1 of the insulating sealing body 14.
Its dimensions are determined so that it is at a position recessed inward from the end surface 14b of 4a. At this time, as shown in FIG. 1(B), the width dL of the frame-shaped part 14c along the peripheral edge 14a of the frame-shaped insulating sealing plate 14 is set from the width d2 of the frame-shaped part along the other peripheral edge. It is preferable to make the peripheral edge of the other terminal plate, that is, the positive electrode terminal plate 12 larger, because this will allow a sufficient overlap between the receded negative electrode terminal plate peripheral edge 13a and the frame-shaped portion 14c of the insulating sealing plate 14. The end surface 12c of the portion 12a is located in the same plane as the end surface 14b of the peripheral portion 14a of the insulating sealing plate 14 described above.

Furthermore, in the flat battery 11 of the present invention.

As shown in FIG. 1(A), not only the peripheral edge 13a of one terminal plate, that is, the negative terminal plate 13, but also all other peripheral edges are moved slightly inward from the peripheral edge of the corresponding insulating sealing plate 14. The retracted configuration is advantageous because it can prevent an external short circuit between the positive and negative terminal plates when a metal member or the like comes into contact with the peripheral edge of the battery after the battery is manufactured.

It is preferable that the dimensions of each component such as the positive and negative electrode terminal plates and the insulating sealing plate are determined as appropriate depending on the dimensions of the entire battery.1For example, in FIG. 1(A), the short side is 16.5ma+, long side y is 34.5m
m, Ipgd1 of the frame portion 14c = 1 to 4 m
m, width d2 of other frame-shaped parts = 0.5 to 3II1 m, width P of lead part 13b of negative electrode terminal plate 13 = 1 to 5 m + w,
The length of the protrusion is u=2~lomm, and the retreat distance of the peripheral edge 13a is flil! It is preferable to set qt=0.5 to 1.5 mm, and set the other peripheral edge part recess distance q2 to 0.2 to 0.5 mm, respectively.

[Example] A flat battery 11 of the present invention as shown in FIG. 1 was manufactured. That is, a power generation unit is constructed by laminating in this order a positive electrode mixture 5 made of manganese dioxide, a conductive material, and a binder, a separator 6 made of a polypropylene nonwoven fabric impregnated with a non-aqueous electrolyte, and a negative electrode sheet 7 made of lithium. The power generation unit is placed between the positive terminal plate 12 and the negative terminal plate 13, and the power generation unit is surrounded by a frame-shaped insulating sealing plate 14 made of, for example, ionomer resin, and these are thermocompression bonded at 200°C. The entire battery was sealed. At this time, the positive and negative terminal plates 12 and 1
3 and the insulating sealing plate 14 and their mutual positional relationships were set as follows. First, in the insulating sealing plate 14, the short side X = 16.5 mm and the long side y = 34.5ff1m.
The width d1 of the frame portion 14c was 3.5 mm, and the width dz of the other frame portions was 2.5 mm. In the negative electrode terminal plate 13, the retreat distance qt of the peripheral edge portion 13a = 1a+m, the retreat distance q2 of the other peripheral edge portion = 0.5111 m, and the lead portion 13b
The width p = 2 mm and the length u = 5 mm were set.

Further, the peripheral end face of the positive electrode terminal plate 12 is all flush with the peripheral end face of the insulating sealing plate 14.

When 1,000 such flat batteries 11 were produced and the batteries after production were examined for the presence or absence of external short circuits, no external short circuits occurred.

For comparison, 1,000 batteries with the conventional structure shown in Figure 2 were also evaluated in the same way.
External short circuits occurred in 23 out of 000. A detailed examination of the battery in which this external short circuit occurred revealed that the lead portion 2
It was confirmed that it was bent at b and 3b and was in contact with another terminal board.

[Effects of the Invention] As is clear from the above description, the flat battery of the present invention has an insulating sealing plate that covers the peripheral end face of one of the positive and negative terminal plates where the extended lead portion is formed. By retracting the lead terminals inward from the peripheral end surface, the protruding length of the lead terminals of each terminal plate is shortened, making it difficult for the leads to bend, and at the same time, if bending occurs, However, the lead part is structured so that it is difficult to contact the other terminal board, so no external short circuit occurs. Therefore, it is extremely reliable as a power supply for ultra-thin card-type electronic devices. It has great industrial value.

[Brief explanation of the drawing]

FIG. 1(A) is a perspective view showing the basic structure of the flat battery of the present invention, FIG. 1(B) is a sectional view taken along line X-X in FIG. 1(A), and FIG. Figure 2 (A) is a cross-sectional view taken along line YY in Figure 2 (A), Figure 2 (A) is a perspective view of a conventional flat battery, Figure 2 (B) is a cross-sectional view taken along line X-X in Figure 2 (A). . 5... Positive electrode mixture, 6... Separator, 7...
・Negative electrode sheet, 11... flat battery, 12...
Positive electrode terminal plate, 12a...Peripheral part, 12b...Lead part, 12c...End face, 13...Negative electrode terminal plate, 13a
... Peripheral portion, 13b... Lead portion, 13c... End surface. 14... Insulating sealing plate, 14b... Frame-shaped part end surface, 14
c...Frame-shaped part. +Al +81 Figure 1 (A) Figure 2

Claims (1)

[Scope of Claims] A laminate in which a positive electrode mixture, a separator, and a negative electrode sheet are laminated in this order; a frame-shaped insulating sealing plate surrounding the laminate; the entire surface of the positive electrode mixture and the insulating sealing plate; a positive electrode terminal plate that covers one plate surface of the plate and is laminated closely thereto; a negative electrode terminal plate that covers the entire surface of the negative electrode sheet and the other plate surface of the insulating sealing plate and is laminated closely thereon; In a flat battery comprising: a peripheral edge of the positive and negative terminal plates along one peripheral edge of the insulating sealing plate;
Each lead portion extends outward, and
The peripheral edge end face of one of the positive and negative terminal plates, on which the lead portion is formed, is arranged so as to form the same plane as the one peripheral edge end face of the insulating sealing plate along the stacking direction of the terminal plate. A flat battery, characterized in that the end face of the peripheral edge on which the lead portion of the other terminal plate is formed is set back inward from the end face of the one peripheral edge of the insulating sealing plate.