JPH0435875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a spiral battery such as a lithium battery or a silver battery, and particularly relates to a method of manufacturing a spiral battery having a structure in which at least one electrode is covered with a separator. be.

FIG. 1 and FIG. 2 are a partially sectional front view and a cutaway plan view of a spiral-shaped battery using a lithium battery as an example.

The elongated cathode plate 1 is constructed by pressing a current collector 3 made of expanded metal onto a lithium plate 2. On the other hand, a long anode plate 5
The anode plate 5 is composed of an anode mixture 6 held in a current collector 7 made of expanded metal, and the anode plate 5 is wrapped in advance with a separator 8 made of a nonwoven fabric such as polypropylene fiber.

The cathode plate 1 and the anode plate 5 are stacked on top of each other, wound spirally around the cathode current collector rod 4, and stored in the inner can 9. Note that, as shown in FIG. 2, the tip 3a of the cathode current collector 3
while the anode current collector 7
The rear end 7a protrudes from the anode mixture 6 and is pressed against the inner peripheral surface of the inner can 9 by its elasticity.

The inner can 9 is inserted into the anode can 10, and an insulating plate 11 made of synthetic resin is interposed between the bottom of the anode can 10, the cathode plate 1, and the cathode current collector rod 4. Furthermore, an insulating ring 12 made of synthetic resin is interposed between the upper bent portion of the inner can 9 and the cathode plate 1. The head of the cathode current collector rod 4 protrudes upward from the inner can 9 and is spot welded to the center of the inner surface of the cathode terminal plate 13. The outer periphery of the cathode terminal plate 13 is fastened to the open end of the anode can 10 via an annular gasket 14 made of synthetic resin.

As the electrolyte for this battery, an organic liquid in which lithium perchlorate is dissolved in a mixed solvent of propylene carbonate and 1,2-ditomexyethane is used.
As the anode mixture 6, a mixture of manganese dioxide, phosphorous graphite, and polytetrafluoroethylene is used.

In conventional batteries of this type, the separator 8 is interposed between the cathode plate 1 and the anode plate 5 by wrapping the separator 8 around one electrode (the anode plate 5 in the above example) as described above; A method of winding the electrode in a spiral shape, a method of sealing the long ends together to form a bag, inserting one electrode into the separator, and winding it in a spiral shape with the other electrode. There is a method of interposing a long separator between a cathode plate and an anode plate and winding the separator in a spiral shape. This method has no problems as long as the electrode is insoluble and the active material does not fall off, but since the electrode is generally soluble and the active material falls off, there is a risk of internal short circuit. With method , there is almost no risk of internal short circuit, but when winding the electrode in a spiral shape, the separator located inside the separator and the separator located outside the electrode have different winding diameters. , the inner separator inevitably wrinkles, thereby forming a gap between the separator 8 and the cathode plate 1 or between the separator 8 and the anode plate 6. If there is a void like this,
The distribution state of the electrolyte and the reaction area of the electrodes become non-uniform, resulting in an increase in internal resistance and insufficient discharge performance.

An object of the present invention is to eliminate such drawbacks of the prior art and provide a spiral-shaped battery having excellent discharge performance.

In order to achieve this object, the present invention covers the entire both sides of an elongated electrode with two elongated separators that are slightly wider than the electrode, and while winding this electrode in a spiral shape, the two separators are separated. At least one side end in the longitudinal direction of the electrodes is overlapped with each other across the electrode, and the overlapping portion is joined together, and the surface of the wound electrode is covered with a separator.

Next, embodiments of the present invention will be described with reference to the drawings. Figure 3 is a cutaway plan view showing the state in which the cathode plate and the anode plate with both sides covered with separators begin to be wound around the cathode current collector rod, and Figure 4 is a partial plan view of the anode plate with both sides covered with separators before sealing. , FIG. 5 and FIG. 6 are a schematic front view and a schematic side view of an electrode winding device, and FIG. 7 is a front view of a main part of a separator seal portion in the electrode winding device.

As shown in FIG. 3, the tip of the cathode current collector 3 protrudes slightly beyond the lithium plate 2, anode plate 5, separator 8, etc., and its tip 3a is spot welded to the side surface of the cathode current collector rod 4. . In this way, the elongated anode plate 5 is stacked on the elongated cathode plate 1 attached to the cathode current collector rod 4.
Both sides of the anode plate 5 are entirely covered with two separators 8. FIG. 4 is a diagram showing the state of this anode plate 5. The elongated anode plate 5 is made of a net-like anode current collector 7 made of expanded metal and holds an anode mixture 6. Both sides are covered by two elongated separators 8, 8, which are slightly wider than 5. This separator 8 is mainly made of thermoplastic fibers such as polypropylene, and the portions protruding from both ends of the anode plate 5 serve as fusing margins 15 .

As shown in FIG. 3, the tip of the anode plate 5 is completely covered by the tip 8a of the separator 8, and if necessary, the tips 8a may be heat-sealed to each other in advance. is also possible. Alternatively, a separator 8 folded in two may be used.

The cathode plate 1 and the anode plate 5, both sides of which are covered with separators 8, are stacked on top of each other and are spirally wound around the cathode collector rod 4 as a core.About this electrode winding device This will be explained using FIGS. 5 to 7.

As shown in FIG. 5, the head 4a and lower end 4b of the cathode current collector rod 4 are held by chucks 16, respectively, and these chucks 16 are rotatably supported by bearings 17. One chuck shaft 16
a is connected to a rotating shaft of a drive motor 19 via a gear group 18. Therefore, when the cathode current collector rod 4 rotates in the direction of the arrow as shown in FIG. 6 due to the driving force transmitted from the motor 19, the electrode polymer 20 (a combination of the cathode plate 1 and the anode plate 5) is rotated by the cathode current collector rod. It can be wrapped around 4.

In order to tightly wind this electrode polymer 20, a plurality of pressure driven rollers 21 are provided on the outer periphery of the wound body.
is being bombarded. Each driven roller 21 has a bearing 2
The cathode current collector rod 4 is received on the central axis of the cathode current collector rod 4 by a pressing spring 23 connected to the cathode current collector rod 4 and pressed uniformly. As the amount of winding of the electrode polymer 20 increases, the diameter becomes larger, so the pressure spring 23 is compressed accordingly, and the pressure driven roller 21 gradually moves radially outward. Although not shown, the movement of the pressure driven roller 21 is guided by a guide member.

When the separator 8 is wound together with the cathode plate 1 and the anode plate 5, the separator 8 on the inside of the anode plate 5 and the separator 8 on the outside are not yet fused and are so-called free from each other. , even if the winding diameters of the separator 8 on the inside of the anode plate 5 and the separator 8 on the outside of the anode plate 5 are different,
The inner separator 8 is gradually shifted relative to the outer separator 8, and the cathode plate 1 is aligned without wrinkles.
and the anode plate 5.

After this electrode polymer 20 is wound around the cathode current collector rod 4, the side ends of the separator 8 are heat-sealed together. That is, as shown in FIG. 7, the separator 8 positioned inside the anode plate 5 by winding
The fusing margin 15 of the anode plate 5 and the fusing margin 15 of the separator 8 located on the outside of the anode plate 5 are sandwiched between the heating roller 24 and the receiving roller 25 in a relatively misaligned state as described above. . Then, the overlapped fusing margins 15 are thermally fused together by heat from a heating roller 24 having a built-in heater, and the surface of the anode plate 5 is completely covered by the two separators 8. Since the fusing margins 15 are continuously fused together over the entire length of the separator 8 in the longitudinal direction, the active material does not fall off.

After the electrode polymer 20 is wound around the cathode current collector rod 4, the battery is assembled according to a conventional method. In addition,
Since the other configurations of the battery are the same as those of the conventional battery described above, a description thereof will be omitted.

In the above embodiment, the welding margin 1 on both sides of the separator 8
5 are respectively fused, but for example, only the fusion margin 15 on the lower side of the separator 8 is fused to form a bag shape,
The upper side of the separator 8 may be left open, and the opening of the separator 8 may be closed with a wide insulating link 12 (see FIG. 1).

Although the heating roller 24 is used in the embodiment, other heating means such as a laser beam or ultrasonic wave may be used as the means for fusing the separator 8.

Since the present invention is configured as described above,
The separator can be wound without wrinkles, and therefore a battery with excellent performance in which a uniform discharge reaction is performed can be obtained.

[Brief explanation of drawings]

Figures 1 and 2 are a partially cross-sectional front view and cutaway plan view of the spiral battery, and Figure 3 shows the state in which the cathode plate and the anode plate, both sides of which are covered with separators, begin to be wound around the cathode current collector rod. 4 is a partial plan view of the anode plate before sealing with both sides covered with separators, FIGS. 5 and 6 are a schematic front view and a schematic side view of the electrode winding device, and FIG. FIG. 2 is a front view of a main part of a separator seal portion in the electrode winding device. DESCRIPTION OF SYMBOLS 1...Cathode plate, 5...Anode plate, 8...Separator, 15...Fusion allowance, 20...Electrode polymer, 24
...Heating roller.

Claims (1)

[Claims] 1. Cover both sides of an elongated electrode with two elongated separators that are slightly wider than the electrode, and while winding this electrode in a spiral, at least one side end of both separators in the longitudinal direction is covered. A method for manufacturing a spiral battery, characterized in that the electrodes are stacked on top of each other, the overlapping parts are joined together, and the electrode surface is covered with a separator.