JPS5910693Y2 - flat battery - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to improvement of flat batteries.

This type of battery is used in small calculators, electronic watches, cameras, hearing aids, etc., and as the power consumption of these devices decreases, there is a trend toward smaller and lighter batteries and longer use without replacement.

Therefore, higher reliability is required of batteries, and the problems are leakage and internal short circuits.

The present invention particularly proposes a battery structure that eliminates internal short circuits, and one embodiment thereof will be described below with reference to the drawings.

Reference numeral 1 denotes a sealing plate which also serves as a negative electrode terminal, and its rim is inserted into an insulating packing 2.

Reference numeral 3 denotes a negative electrode, which is made of a lithium rolled plate and is press-bonded to a negative electrode current collector network 4 fixed to the inner bottom surface of the sealing plate 1 by spot welding.

As shown in FIG. 2, an insulating ring 5 made of polypropylene, polyethylene, etc. is fitted onto this negative electrode 3.

6 is a separator made of a polypropylene nonwoven fabric impregnated with a non-aqueous electrolyte that dissolves lithium perchlorate in propylene carbonate, and 7 is a positive electrode whose active material is manganese dioxide. It is fitted into the positive electrode inner can 8 for the purpose of reinforcement.

These electrode groups are connected to the sealing plate 1 and the insulating packing 2.
They are sequentially stacked in a battery case formed by an outer can 9 which also serves as a positive electrode terminal, and a sealing plate is caulked therebetween.

Incidentally, the positive electrode inner can 8 is formed with a flange 8', and this flange 8' is disposed so as to be in contact with the inner bottom surface of the outer can 9, so that the positive electrode and the outer can are simply connected. The current collecting effect is improved compared to electrical connection by contact.

Now, in the second type of flat battery, a structure is adopted in which a pair of electrodes are laminated with a separator interposed in a battery case formed by fixing a sealing plate and an outer case through insulating packing. However, due to horizontal extension of the lithium negative electrode, which is a soft metal, during the pressurization (caulking) process during battery assembly, or expansion of the electrode during discharging, the separator may be broken through and the peripheral edges of the pair of electrodes may There is a concern that contact may cause an internal short circuit.

According to the present invention, however, since the insulating ring is fitted around the periphery of the lithium negative electrode, short circuiting between the two electrodes can be prevented even if the electrode expands.

FIG. 3 shows another embodiment of the present invention, in which a separator 6' is placed on one side of the negative electrode 3 and is integrally punched out, and this is fitted into an insulating ring 5. Compared to the case where the negative electrode 3 and the separator 6' are assembled in a single unit in advance, the assembly work is simplified and the separator 6' can be prevented from shifting.

As mentioned above, the battery structure according to the present invention has high reliability because there is almost no internal short circuit, and for current collection of the positive electrode, the positive electrode is fitted into a positive electrode can with an inward flange on the bottom surface. The positive electrode and the outer can are electrically connected through this rim, and it has the advantage of improving the current collection effect compared to the case where the positive electrode and the outer can are in direct contact. The value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of a flat battery according to an embodiment of the present invention, FIG. 2 is a perspective view of an insulating ring, and FIG. 3 is a half-sectional view of a flat battery according to another embodiment of the present invention. show. 1... Sealing plate, 2... Insulating packing, 3... Negative electrode, 5, 5'... Insulating ring, 6, 6'... ...Separator, 7...
Positive electrode, 9...Exterior can.

Claims (1)

[Scope of Claim for Utility Model Registration] ■ A battery case is formed by fixing a sealing plate that also serves as a negative electrode terminal and an outer case that also serves as a positive electrode terminal through edge packing, and a negative electrode made of a lithium plate is attached to the periphery of the container. An insulating ring is fitted and crimped onto the inner bottom surface of the sealing plate, and the positive electrode is fitted into a positive electrode inner can with an inward flange provided on the lower surface, and the positive electrode is disposed on the inner bottom surface of the outer can. flat battery. (2) The flat battery according to claim (2) of the utility model registration, wherein the negative electrode made of the lithium plate and the separator are integrated, and the insulating ring is fitted around the periphery of the negative electrode.