JPH0794165A - Organic electrolyte battery - Google Patents

Abstract

PURPOSE:To provide an organic electrolyte battery having high safety by completely preventing the occurrence of shortcircuit between a negative electrode current collector tab connected to the bottom of a battery can, and a spiral electrode body. CONSTITUTION:Regarding an organic electrolyte battery equipped with a spiral electrode body 6 formed out of a strip type positive electrode 2 and a strip type negative electrode 3 spirally wound via a separator 4, the can bottom is provided with a disc type insulation plate 7 with the external surface thereof kept adjacent to the internal surface of a battery can 1. Also, a circular slit 8 having an angle between 60 and 120 degrees externally from the center of the insulation plate 7 is formed and, then, a negative electrode current collector tab 9 is inserted in the slit 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electrolyte battery such as a cylindrical lithium battery provided with a spiral electrode body, and more specifically, a negative electrode current collecting tab and a spiral electrode connected to the bottom of a battery can that also serves as a negative electrode. The present invention relates to an organic electrolyte battery having excellent safety in which a short circuit with the body is completely prevented.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 6, a can bottom of a cylindrical lithium battery, which is a kind of organic electrolyte battery, has a strip-shaped positive electrode in which a positive electrode mixture is held in a battery can 1 which also serves as a negative electrode. 2 and a strip-shaped negative electrode 3 made of lithium or the like and a separator 4
A negative electrode current collecting tab 9 covered with a negative electrode current collecting tab insulating tape 10 is filled with a spirally wound electrode body 6 which is wound in a spiral shape through a wire, and the outer peripheral portion of the wound body is covered with an insulating film 5. The insulating plate 7a has a cutout 8a as shown in FIG. 7 interposed in the bottom of the can, and is bent downward from the cutout 8a and spot-welded to the bottom of the can.

[0003]

However, in this type of cylindrical lithium battery, the negative electrode current collecting tab 9 is bent downward from the notch 8a of the insulating plate 7a which is interposed in the bottom of the can. The battery can 1 and the spiral electrode body 6 in the cutout portion.
There is no insulation between and. Therefore, the bending position of the negative electrode current collecting tab 9 is not regulated, and the negative electrode current collecting tab 9 may be bent in the peripheral direction of the battery can 1 and short-circuited with the spirally wound electrode body 6 to ensure sufficient safety. There was a drawback that it could not be secured. Further, if a disk-shaped insulating plate whose outer periphery is adjacent to the inside of the battery can is used without providing notches or slits, the negative electrode current collecting tab 9 must be the outermost periphery of the electrode body, even if the tab position is inside. Even if the current collection efficiency is better in the circumferential direction, the tab position cannot be moved, and thus sufficient characteristics may not be obtained.

[0004]

The present invention has been made as a result of various studies in order to eliminate such a drawback, and is connected to the can bottom between the can bottom of a battery can also serving as a negative electrode and the spiral electrode body. Provided with an arc-shaped slit through which the negative electrode current collector tab
By interposing a disc-shaped insulating plate whose outer periphery is adjacent to the inner periphery of the battery can, the battery can and the spirally wound electrode body are completely separated by the insulating plate, and the bending position of the negative electrode current collecting tab is determined by the insulating plate. It is regulated according to the slit of so that the negative electrode current collection tab does not bend in the peripheral direction of the battery can,
It is possible to completely prevent a short circuit between the negative electrode current collecting tab and the spirally wound electrode body, sufficiently secure the safety of an organic electrolyte battery such as a cylindrical lithium battery, and obtain an organic electrolyte battery with excellent safety It is the one.

Further, the slit provided on the disk-shaped insulating plate is formed into an arc shape substantially along the outer circumference of the insulating plate, so that the wound negative electrode current collecting tab can be easily inserted and the workability is improved. In addition, the position of the negative electrode current collecting tab can be changed by changing the position of the arc-shaped slit, and the slit position can be freely adjusted according to the position of the negative electrode current collecting tab with the best current collecting efficiency. Is to be able to determine.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cylindrical lithium battery which is a kind of organic electrolyte battery of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a bottom portion of a cylindrical lithium battery of the present invention. Reference numeral 1 is a battery can that also serves as a negative electrode. A strip-shaped positive electrode 2 holding a positive electrode mixture in the battery can 1.
And a strip-shaped negative electrode 3 made of lithium or a lithium alloy
Is wound in a spiral shape through a separator 4 made of a film such as polypropylene or polyester, and the spiral electrode body 6 in which the outer peripheral portion of the wound body is covered with an insulating film 5 is filled.

Reference numeral 7 denotes a disc-shaped insulating plate interposed between the can bottom of the battery can 1 and the spiral electrode body 6, and has an arc-shaped slit 8 as shown in FIGS. Is adjacent to the inner circumference of the battery can and the negative electrode current collecting tab 9 connected to the bottom of the can is passed through the arc-shaped slit 8. Reference numeral 10 is an insulating film covering the negative electrode current collecting tab 9.

Thus, the can bottom of the battery can 1 and the spiral electrode body 6
Are completely isolated from each other by an insulating plate 7 interposed therebetween, and a short circuit between the negative electrode current collecting tab 9 and the lower bottom of the battery can 1 is completely prevented.

FIGS. 3 to 5 show a process of welding and connecting the negative electrode current collecting tab 9 to the lower bottom of the battery can 1 with the insulating plate 7 interposed therebetween. Then
Using the welding table 12 in which the auxiliary electrode rod 11 is erected, first, as shown in FIG. 3, the central electrode space of the spiral electrode body 6 is fitted on the auxiliary electrode rod 11.

Then, as shown in FIG. 4, the spiral electrode body 6
The arc-shaped slit 8 provided in the insulating plate 7 is aligned with the negative electrode current collecting tab 9 derived from the above, and the insulating plate 7 is placed on the spiral electrode body 6. As described above, since the slit 8 of the insulating plate 7 is provided in a circular arc shape, the wound negative electrode current collecting tab 9 having a curvature can be easily inserted, and the workability is improved.

After that, as shown in FIG. 5, the negative electrode current collecting tab 9 projecting on the insulating plate 7 is bent on the insulating plate 7 and the battery can 1 is fitted on the spirally wound electrode body 6 and then on the insulating plate 7. The negative electrode current-collecting tab 9 bent to be in contact with the lower bottom of the battery can 1 is spot-welded with the auxiliary electrode rod 11 to be connected to the lower bottom of the battery can 1.

When the negative electrode current collecting tab 9 is welded and connected to the lower bottom of the battery can 1, the negative electrode current collecting tab 9 covered with the insulating film 10 is provided with the bending position in an arc shape of the insulating plate 7. It is regulated according to the slit 8 formed, and the negative electrode current collecting tab 9 is not bent in the peripheral direction of the battery can 1.

Therefore, a short circuit between the negative electrode current collecting tab 9 and the spirally wound electrode body 6 is completely prevented, safety is sufficiently ensured, and a cylindrical lithium battery having excellent safety is obtained.

Here, since the insulating plate 7 is constantly exposed to the electrolytic solution in which the lithium salt is dissolved in the non-aqueous solvent injected into the battery can 1, the thickness of the insulating plate 7 is set so as not to be corroded by the electrolytic solution. It is preferable that it has an organic solvent resistance of 0.5 mm, and as such an insulating plate 7, one made of polypropylene or polyester is usually used.

The slit 8 provided in the insulating plate 7 is preferably arcuate along the outer peripheral line of the insulating plate 7 and has an angle of 60 ° to 120 ° from the center of the insulating plate 7 to the peripheral direction. When the arc has an angle of 120 °, the negative electrode current collecting tab 9 is easily inserted, the work efficiency is excellent, and the bending abnormality does not occur. On the other hand, when the angle is 60 ° or less, the work of inserting the negative electrode current collecting tab 9 becomes difficult, and the work efficiency deteriorates. On the other hand, at 120 ° or more, even if the negative electrode current collecting tab 9 is inserted into the slit 8 of the insulating plate 7, it becomes difficult to regulate the negative electrode current collecting tab 9 with the slit 8, and bending abnormalities are likely to occur, and empty As the number of locations increases, the possibility of short circuit increases.

[0016]

As described above, in the organic electrolyte battery of the present invention, the negative electrode current collecting tab connected to the can bottom is provided between the can bottom and the spirally wound electrode body of the battery can also serving as the negative electrode. Since a circular arc-shaped slit is provided and a disk-shaped insulating plate whose outer circumference is adjacent to the inner circumference of the battery can is interposed, the battery can and the spiral electrode body are completely separated by the insulating plate. Further, the work of inserting the negative electrode current collector tab having a curvature by being wound by the arcuate slit is facilitated, and further, the bending position of the negative electrode current collector tab is regulated according to the arcuate slit of the insulating plate. Since the current collector tab does not bend in the direction of the periphery of the battery can, a short circuit between the negative electrode current collector tab and the positive electrode of the spirally wound electrode body is completely prevented, ensuring sufficient safety and ensuring safety. An organic electrolyte battery having excellent properties is obtained.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a lower bottom portion of a cylindrical lithium battery showing an example of an organic electrolyte battery of the present invention.

FIG. 2 is a plan view of an insulating plate used in the cylindrical lithium battery of FIG.

FIG. 3 is a perspective view showing a step of welding and connecting a negative electrode current collecting tab to a lower bottom of a battery can with an insulating plate interposed in the cylindrical lithium battery of FIG.

FIG. 4 is a perspective view showing a process of welding and connecting a negative electrode current collecting tab to a lower bottom of a battery can with an insulating plate interposed in the cylindrical lithium battery of FIG.

5 is a perspective view showing a process of welding and connecting a negative electrode current collecting tab to a lower bottom of a battery can with an insulating plate interposed in the cylindrical lithium battery of FIG. 1. FIG.

FIG. 6 is an enlarged sectional view of a lower bottom portion of a conventional cylindrical lithium battery.

7 is a plan view of a can bottom insulating plate used in the cylindrical lithium battery of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery can 2 Positive electrode 3 Negative electrode 4 Separator 5 Insulating film 6 Swirl electrode body 7 Insulating plate 8 Slit 9 Negative electrode current collecting tab 10 Insulating film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiji Nakamura, 1-88, Tora, Ibaraki-shi, Osaka Prefecture, Hitachi Hitachi Maxel Co., Ltd. (72) Tomio Kitamura, 1-88, Tora, Ibaraki-shi, Osaka Hitachi Maxel Co., Ltd.

Claims (1)

[Claims] 1. An organic electrolyte battery comprising a spirally wound electrode body formed by spirally winding a strip-shaped positive electrode and a strip-shaped negative electrode with a separator interposed between the can bottom of a battery can and the spirally wound electrode body. And a disk-shaped insulating plate whose outer circumference is adjacent to the inner circumference of the battery can on the bottom of the can, and an arc shape having an angle of 60 ° to 120 ° from the central direction of the insulating plate to the peripheral direction. An organic electrolyte battery having slits.