JPS58126677A - Flat battery - Google Patents

Abstract

PURPOSE:To obtain a flat battery, the battery case on the equipment side of which can be made thinner, by providing a positive and a negative terminal on one of the two surface parts. CONSTITUTION:A positive and a negative current-collecting plate 6 and 7 are placed on a film 1 in such a manner that they are separated from one another and block a positive and a negative terminal hole 3 and 4 respectively. Next, a negative active material layer 9 is provided on a first surface part 1a in such a manner that the layer 9 touches the negative current-collecting plate 7, and a separator 10 impregnated with electrolyte is provided in such a manner that a part of the plate 7 is covered with the separator 10. Then, a positive active material layer 11 is provided in such a manner that most part of a second surface part 16 is covered with the layer 11. After that, the film 1 is folded on its center 2, and the joining parts are fused together, thereby completing a flat battery.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flat battery having positive and negative terminals on one side.

With recent advances in the size and weight of devices using batteries, there is a demand for smaller and lighter batteries, and there is also a strong demand for thinner batteries. Against this background, various thin batteries have been proposed. A typical example is a flat battery with a thickness of about 1 to 2 mi+, in which positive and negative electrodes are stacked one above the other with a separator in between and sealed with two exterior films.

Since this flat battery has positive and negative electrodes stacked one above the other, the positive and negative electrode terminals are necessarily placed above and below the battery.

When using this type of battery, it is common to provide a leaf spring-like terminal in the battery case, and to take out the output by press-contacting this to the terminal portion of the battery. Therefore, if the battery has terminals on the top and bottom as described above, the battery thickness should be 1.
rsmm, and if the thickness of the leaf spring on the battery case side is in two order, the thickness of the groove for storing the battery in the battery case needs to be 6.6 mm at the bottom. I can't take advantage of it. However, if the positive and negative terminals of the battery are provided on one side of the battery, the gap between the battery cases can be 3.5 mm.

In view of the above, the present invention provides an effective battery configuration that provides a flat battery having positive and negative terminals on one side.

The present invention will be explained below using examples.

1 to 6 show the battery assembly process. 1 is a heat-adhesive exterior film, which is constructed by laminating polyester films on the top and bottom of a thin metal plate such as aluminum foil. In the final step, the film is folded in the center and the three peripheral parts are heat welded together to seal the power generation element inside. Hereinafter, with the central portion 2 of the film as a boundary, the left surface portion 1a will be referred to as a first surface portion, and the right side portion 1b will be referred to as a second surface portion. 3 and 4 are positive and negative terminal holes drilled on the second surface side, and 6 is an adhesive margin.

First, positive and negative electrode current collector plates 6.degree. 7 are separated from each other on this film, and the current collector plates with positive and negative electrode terminal holes of 3.degree. are fixed to the film 1 by thermal bonding.

In this example, the negative current collector plate 7 is sized to cover the peripheral portion of the terminal hole 4 from the first surface portion 12L excluding the adhesive margin, and the positive current collector plate 6 is spaced apart from the current collector plate 7. 8 was left in the L-shape to cover the part of the second surface part 1b excluding the adhesive margin, but these current collector plates may be small if one side protrudes from the first surface part. good. However, in order to prevent the battery from losing its shape, it is best to use the size shown in the figure.

A separator 10 impregnated with an electrolytic solution is provided so as to cover the negative electrode active material layer 9 and the exposed negative electrode current collector plate 7 (FIG. 4).

Next, the positive electrode active material layer 11 is disposed so as to be in contact with the positive electrode current collector plate 6 and to cover most of the second surface part so as to cover the separator (Fig. 6), and finally, the film 1 is placed on the positive electrode active material layer 11. A flat battery is completed by bending it at the center 2 and thermally bonding the joining margins on the three sides to each other (Fig. 6).

A lithium metal sheet is used as the negative electrode active material layer, a mixture of fluorocarbon, acetylene plaque, and a resin binder is bonded to a titanium lath plate as the positive electrode active material layer, γ-butyrolactone in which lithium borofluoride is dissolved as the electrolytic solution,
A polypropylene non-woven fabric was used as the separator, and an aluminum plate and a nickel plate were used as the positive and negative electrode current collector plates, each having minute protrusions formed on the surfaces in contact with the active material layer. The 5th battery is 500Ω
It exhibited a capacity of about 3 s o mAh in constant resistance discharge.

As described above, in the flat battery of the present invention, the positive and negative terminal holes are provided on the second surface side of one exterior film, and the positive and negative electrode current collector plates are arranged to cover the terminal holes and the negative electrode. The current collector plate is arranged so as to span the first surface part, and the negative electrode active material layer is further arranged on the first surface part 7, and the negative electrode side is covered with the separator, so that the second Most of the surface area can be used as a location for the positive electrode active material layer, and the opposing area of the positive and negative electrodes can be increased. In addition, since the positive and negative terminal holes are arranged on one side of the battery, it is possible to make the thickness of the battery case on the device side even thinner, and the side of the battery that does not have terminal holes can be completely covered. Since it is in close contact with the battery case, it has the advantage that the battery is less likely to shift within the case due to vibration. It goes without saying that a structure in which the above positive and negative electrodes are interchanged may also be used.

As described above, according to the present invention, it is possible to obtain a flat battery which is advantageous in making the battery case of the device thinner.

[Brief explanation of the drawing]

1 to 6 are plan views showing the assembly process of a battery according to an embodiment of the present invention, and FIG. 7 is an enlarged sectional view taken along line A' in FIG. 6. 1... Exterior film, 1a... First surface part,
1b... Second surface portion, 3, 4... Terminal hole, 6... Joining space, 6, 7... Current collector plate,
9, 11...Living material IN, 10...Separator. 11 Figure 15 Figure 116 Figure ↑ 4' $1!7 Figure 33

Claims (1)

[Claims] A single exterior film having a first surface portion and a second surface portion provided with positive and negative terminal holes is bent at the center to form the first. A flat battery in which a power generation element is sealed in a film by bonding three peripheral parts of a second surface part to each other, and the first
a current collector plate of one electrode disposed from a surface portion to a second surface portion; and a current collector plate of one electrode disposed on the second surface portion so as to be isolated from the current collector plate and close the terminal hole of the other electrode. a current collector plate of the other electrode, and an active material layer of one electrode disposed in contact with the one current collector plate at the first surface portion;
A separator layer disposed to cover the active material layer and the exposed portion of the current collector plate, and an active material layer of the other electrode disposed in contact with the other current collector plate at the second surface portion. A flat battery having.