JPS6029803Y2 - flat battery - Google Patents

Description

[Detailed description of the invention] This invention is a flat battery made by stacking a positive electrode mixture, a separator, and a negative electrode in order on a positive electrode current collector plate, and sealing these with a cover material having positive and negative terminal openings. It is related to
The purpose is to improve the conductivity between the positive electrode mixture and the positive current collector plate.

In response to the recent trend toward smaller and thinner electronic devices, ultra-small and thin flat batteries have been devised as power sources for these devices.

FIG. 2 shows a flat battery previously proposed by the present inventor, in which a protrusion 5a provided on a positive electrode current collector plate 5 and a porous metal core material 2 embedded in a positive electrode mixture 1 are in contact with each other. This was used to collect current from the positive electrode.

With this structure, when the battery expands due to gas generated during high-temperature storage, the protrusions 5a formed on the positive electrode current collector plate 5
As a result, contact with the porous metal core material 2 embedded in the positive electrode mixture was impaired, and there was a problem with heavy load discharge characteristics after high-temperature storage.

Note that the discharge performance will be slightly affected by the pressure applied to the positive and negative electrodes of the flat battery by the contact terminals of the electronic equipment used, but the pressure applied to this type of flat battery is around 100 g/d, so
With this current collection method, poor contact occurs during heavy load discharge after high-temperature storage, making it difficult to extract electricity.

The present invention is achieved by bending the porous metal core material embedded in the positive electrode mixture at the end face of the positive electrode mixture, extending it to a position corresponding to the positive electrode terminal extraction opening of the outer covering material, and contacting the positive electrode current collector plate. The present invention provides a flat battery that ensures electrical connection between the positive electrode mixture and the positive current collector plate and that can withstand heavy load discharge after storage at relatively high temperatures.

Hereinafter, the present invention will be explained with reference to FIG. 1 showing an embodiment thereof.

In the figure, 1 is a positive electrode mixture whose main component is manganese dioxide, and 2 is a porous metal core material made of a stainless steel net. The mixture 1 and the core material 2 are integrally bonded by coating on both sides.

3 is a separator, 4 is a negative electrode made of a zinc plate, 5 is a positive electrode current collector plate made of a stainless steel plate, 6 is a negative electrode current collector plate made of a brass plate, and 7 and 8 are outer covering materials made of a plastic film, respectively. It has a negative terminal outlet opening 9.10.

To assemble this battery, current collecting plates 5,
6 are joined together by heat welding or the like.

Next, the positive electrode mixture 1 is placed on the current collector plate 5 bonded to the outer covering material 7.
, separator 3 and negative electrode 4 are stacked in this order.

At this time, the extension portion 2a of the core material 2 embedded in the positive electrode mixture 1 is bent at the end face of the mixture and brought into contact with a position corresponding to the opening 9 of the positive electrode current collector plate 5.

Next, the outer covering material 8 is superimposed, three sides around the outer covering material 7°8 are heat welded, and an electrolytic solution consisting of a 3% aqueous solution of zinc perchlorate is injected from one open side. The inside of the battery is reduced in pressure and the opening is sealed by heat welding.

In this way, in the flat battery of the present invention, the extension portion 2a of the porous metal core material 2 embedded in the positive electrode mixture 1 is connected to the positive electrode current collector plate 5.
Since the positive electrode mixture is brought into contact with the position corresponding to the terminal extraction opening 9, the conductivity between the positive electrode mixture and the positive electrode current collector plate is improved, and the current collection efficiency is also excellent.

As a result, even if the battery expands due to gas generated during high-temperature storage, the extension part 2a of the porous metal core material 2 and the positive electrode current collector plate 5
The heavy load discharge performance after high-temperature storage, which has been a problem in the past, is far superior to that of conventional flat batteries, and the electrical contact between the battery and the battery remains intact, making it suitable for use in electronic devices, etc. Can be widely used as a power source.

In addition, since the extension part 2a of the core material 2 is bent and sandwiched between the mixture 1 and the current collector plate 5, it may contact the outer covering material and break through it, or contact the negative electrode and cause a short circuit. It never occurs.

In particular, in the battery manufactured as in the example, the extension part 2a of the porous metal core material 2 has some elasticity and is located at a position corresponding to the positive electrode extraction opening 9, so that it cannot be incorporated into an electronic device. When in use, pressure is applied to the terminal extraction opening by the terminal of the device, causing the extension part 2a of the core material to
Since the contact between the extension part 2a and the positive electrode current collector is strengthened, and the sealing treatment of the battery is also performed under reduced pressure, the degree of adhesion between the extension part 2a and the positive electrode current collector is further strengthened, making it difficult to collect current after high-temperature storage. The efficiency will be very good.

Next, the length 70 mm and the width 2rIrIn shown in FIG.
1. Battery A of the present invention with a thickness of 0.8 mm and conventional battery B shown in Fig. 2 were stored for a specified period at a relative humidity of 50% and a temperature of 60°C, and then stored at a relative humidity of 50% and a temperature of 20°C. The capacitance was determined by applying a pressure of 100 g/c1ft to the electrode terminal portion and discharging with a load resistance of 300Ω.

FIG. 3 shows the capacity after storage as a residual ratio to the capacity immediately after manufacture.

As described above, according to the present invention, a flat battery having excellent discharge performance even after high-temperature storage can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the main parts showing an embodiment of the flat battery of the present invention, FIG. 2 is a vertical cross-sectional view of the main parts showing a conventional flat battery,
FIG. 3 shows a comparison of the residual discharge capacity during storage of a conventional flat battery and a flat battery of the present invention. DESCRIPTION OF SYMBOLS 1... Positive electrode mixture, 2... Porous metal core material, 2a... Extension part, 3... Separator, 4... Negative electrode, 5... Positive electrode current collector plate,
7, 8...Outer cover material, 9...Positive terminal extraction opening.

Claims (1)

[Scope of utility model registration request] A flat battery consisting of a positive electrode mixture with a porous metal core embedded in it, a separator, and a negative electrode stacked one on top of the other on a positive electrode current collector plate, and then sealed with a jacket material that has openings for taking out the positive and negative electrode terminals. Then, the extension of the porous metal core embedded in the positive electrode mixture was bent at the end face of the positive electrode mixture, extended to a position corresponding to the positive electrode terminal extraction opening, and brought into contact with the positive electrode current collector plate. A flat battery characterized by: