JPS5830073A - Manufacture of battery - Google Patents

Abstract

PURPOSE:To increase the amount of electrolyte to improve discharge performance in the manufacture of a cylindrical battery which is assembled by inserting a swirl-shaped electrode group into an inner can. CONSTITUTION:The end of a net 3a of a negative plate 3 which is constructed by pressing a metallic lithium sheet 3b to the current collecting net 3a is inserted into a slit 2a of a current collector 2, the negative plate 3 is bent along the outer surroundings of the collector 2, and a part of the bent part is spot- welded to the outer surroundings of the collector 2. A positive plate 5 covered with a separator 4 is stacked on the outer side of the negative plate. They are wound around the collector 2 to form a swirl-shaped electrode group 1. This electrode group 1 is inserted into an inner can 6, and the upper surface of a collar 6a of the inner can 6 is coated with toluene solution of pitch, then dried to form a sealer layer. A sealing gasket 8 is mounted in the circumference of a sealing plate 7, this sealing plate 7 is put on the inner can, and bonded by spot-welding to the upper end of the current collector 2. The assembled body of the electrode plate and the sealing plate constructed in this process are reversed, then after needle-like nozzle 13a is inserted into the open part of the current collector 2, an electrolyte is poured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method of manufacturing a cylindrical battery assembled by covertly inserting a spiral plate group.

More specifically, a group of spiral electrode plates wound around the current collector rod of one electrode is secretly inserted, and a sealing plate is connected to the upper end of the current collector rod that protrudes upward. The present invention relates to a method for manufacturing a battery in which a sealing packing attached to the peripheral edge of a sealing plate is tightened and sealed by the closed end of an outer can using the inward flange provided on the upper part of the inner can as a seat.

In this way, batteries that use an assembly of a cover plate into which a group of electrode plates is inserted and a sealing plate fitted with sealing packing can be assembled reliably, are highly resistant to vibrations and shocks, and are capable of high-rate discharge. This makes it suitable for high energy density organic electrolyte batteries.

However, there are problems with the operation of injecting electrolyte into the electrode plate group, and it may not be possible to inject enough liquid into the electrode plate group, making it impossible to obtain the desired discharge characteristics, or the electrolyte that is not absorbed by the electrode plate group may leak to the outside. There was an inconvenience that it would leak.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for assembling a battery that eliminates such inconveniences, allows the electrode plate group to retain a sufficient amount of liquid, and does not leak liquid.

The present invention will be explained below using examples.

FIG. 1 shows the overall structure of the battery of the example. Reference numeral 1 denotes an electrode plate group in which a negative electrode plate 3 and a positive electrode plate 6 surrounded by a separator 4 are spirally wound around a negative electrode current collector rod 2 . In addition,
The current collector rod 2 is constructed by cutting out a part of the circumference of a hollow cylindrical body in the vertical direction. The negative electrode 3 is constructed by crimping a metal lithium sheet to a current collector made of net or the like, inserting the end of the current collector into the notch 2a of the current collector rod 2, and fixing it to the rod 2 by spot welding. . The positive electrode 6 is formed by molding a mixture containing manganese dioxide as an active material around a current collector made of a net or the like, and is surrounded by a separator 4 made of a non-woven polypropylene fabric. Only the current collector 6a is exposed.

Reference numeral 6 denotes a metal inner can having an inward facing flange 6a at its upper end, and accommodates the above-mentioned electrode plate group from its lower open end. The exposed portion of the current collector of the positive electrode 6 is in contact with the inner surface of the inner wall 6.

Reference numeral 8 indicates a sealing plate which also serves as a negative electrode plate terminal, and 8 indicates a sealing packing made of polypropylene and having an abbreviated cross-section, into which the bent portion of the peripheral edge of the sealing plate is fitted. Then, the upper end of the negative electrode current collector rod 2 is connected to the inside of the sealing plate 7 by spot welding, and
The lower surface of the sealing packing 8 is adhered to the upper surface of the flange 6a of the inner cover 6 with a sealant 9.

1o is an outer can that also serves as a positive terminal, and inside this is an insulating bottom plate 11.
, and the electrode plate group-sealing plate assembly configured as described above are inserted, and then the open end of the outer can is tightened to the peripheral edge of the sealing punching 8 to construct a sealed battery. The electrolytic solution used is, for example, a mixed solvent of propylene carbonate and 1,2-dimethoxyethane in which 1 mol/l of lithium perchlorate is dissolved.

In the conventional example, a structure in which the inner cover 6 and the sealing packing 8 are bonded with a sealant is not adopted, but a sealing structure in which the electrode plate group is inserted as described above and the inner cover 6 and the sealing packing 8 are attached is used. In a configuration using an assembly in which the plate 7 is integrated,
The flange part 6a of the inner cover 6 serves as a seat for the sealing packing 8, and the current collector rod 2 still serves as a support for supporting the sealing plate 7, so that a strong seal can be achieved, and the electrode plate group is attached to the inner cover's flange. Since it is held by the portion 6a and the bottom of the outer can, it has characteristics such as being strong against vibrations and shocks.

However, in batteries with this type of structure, there is a problem in the electrolyte injection process, making it impossible to retain a sufficient amount of liquid in the electrode plate group, and therefore unable to bring out sufficient discharge performance. Ta.

That is, in the conventional example, the bottom plate 11 is inserted, a certain amount of electrolyte is injected into the outer can (0), and then the inner can (6) in which the electrode plate group 1 and the sealing plate (7) are integrated is inserted. was taken. In this case, the electrolyte in the outer can is pressed by the tightly wound electrode plate group, and the pumping action causes the electrolyte to rise up the inner wall of the outer can and leak to the outside. To prevent this, if the insertion speed of the electrode plate group is slowed down, the leakage will be improved to some extent, but this will be very disadvantageous in terms of productivity. Furthermore, since air does not freely circulate with the outside in the space 12 formed inside the sealing plate 7, there is no place for the air to escape as the liquid permeates and replaces the air, which limits the amount of liquid. I was supposed to. In particular, since organic electrolyte batteries require a large amount of liquid, it has been difficult to achieve sufficient discharge performance.

The present invention eliminates these conventional drawbacks, and will be explained in detail with reference to the manufacturing process shown in FIG.

First, the end of the negative electrode plate 3 (made by crimping a metal lithium sheet 3b to a current collecting net 3a) is inserted into the notch 2d of the current collecting rod 2, and is bent along the outer periphery of the rod 2. A part of the section is spot welded to the outer periphery of the rod 2. Next, a positive electrode plate 5 surrounded by a separator 4 is stacked on the outside of the negative electrode, and these are wound around the rod 2 to form a spiral electrode plate group 1.

Next, insert this electrode plate group 1 into the inner plate 6, and
A toluene solution of pitch is applied to the top surface and allowed to dry to form a layer of sealant.

On the other hand, a sealing packing 8 is fitted around the periphery of the sealing plate 70, and this is placed over the above-mentioned inner space, and the sealing plate 7 is attached to the current collecting rod 2.
It is joined by spot welding to the upper end of the. Still pressing the sealing packing 8 against the interior, the sealant 9 completely adheres the bottom of the backing 8 to the flange 6a.

When the thus constructed assembly of the electrode plate group and the sealing plate is turned upside down, the sealing plate 7 is shown as shown in FIG.
The bottom and the container will be formed. In other words, the space 12 that is fluid-tightly surrounded by the sealing plate 7, the sealing packing 8 attached to the periphery of the sealing plate 7, and the inner cover 6 bonded to the backing and the sealant 9 can be used as a liquid storage section. In this state, as shown in FIG. 3(a), if the needle nozzle 13a of the liquid injection device 13 is inserted into the opening of the current collector rod 2 and liquid is poured,
The electrolytic solution flows into the space 12 through the liquid passage 2b formed in the hollow part of the rod 2. Then, when the electrolyte level within the space 12 rises and reaches the electrode plate group exposed in the space, it smoothly penetrates into the electrode plate group due to capillary action. Moreover,
The other end of the electrode plate group is released into the canister and replaced with the electrolyte.It can easily escape to the outside and complete injection of a predetermined amount of liquid in a short time. I can do it.

Next, in this state, the bottom plate 11 is placed on the open end side of the inner can 6, and then the outer can 10 is placed upside down and placed over the inner can from above. In this case, since the above-mentioned assembly is a container that is open only at the top, the pumping action that occurs when inserting the inner container into the outer can filled with liquid by the conventional method does not occur, and there is no problem of leakage. Not at all.

Next, according to a conventional method, the open end of the outer can 10 is covered with a backing 80.
Complete battery assembly by crimping around the edges.

Next, using a battery with a diameter of 11.6 mm, a height of 10 mm, and a size of 8 MIL, leakage conditions were investigated in the liquid injection step (d) and the insertion step into the outer can (e) according to the present invention. However, there was no leakage at all. On the other hand, - In the conventional example, in the process of inserting the electrode plate group assembly of the outer can, 7 out of 100
o units leaked, and 60 out of 100 units leaked during the sealing process by caulking the outer cans.

In addition, each of the battery I according to the present invention and the battery H according to the conventional method
FIG. 4 shows a comparison of the characteristics when discharged under a load of 100Ω at 20°C.

As described above, according to the method of the present invention, an electrolytic solution can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side view with the main parts of the battery according to the present invention cut out, FIG. 2 is a longitudinal cross-sectional view showing an assembly of an electrode plate group and a sealing plate, and FIG.
The figure shows the battery assembly process, and FIG. 4 shows a comparison of discharge characteristics. 1... Electrode plate group, 2... Current collector rod, 2a.
...Notch, 2b...Liquid passage, 3...
... Negative electrode, 4 ... Separator, 6 ...
・Positive electrode, 6...inner part, 6a... collar part,
7...Sealing plate, 8...Sealing packing, 9...Sealant, 10...Outer can, 12
...Space section, 13... Liquid injection device. Name of agent: Patent attorney Toshio Nakao and 1 other person-1
Figure) 1 1s2 Figure 113 Figure/2 7

Claims (1)

[Claims] An electrode plate group is constructed by winding a negative electrode plate and a positive electrode plate in a spiral shape around a lower part of the current collector rod with a liquid passage opening from the lower end opening to the vicinity of the upper end via a separator. a step of inserting the electrode plate group number into the inner plate having an inward facing flange at the upper end; and a step of gluing the bottom of the sealing packing attached to the peripheral edge of the sealing plate to the flange with a sealing agent; a step of combining the inner surface of the current collector rod with the upper end of the current collector rod to form an assembly of a sealing plate and an electrode plate group, and a step of injecting an electrolytic solution from the liquid passage of the current collector rod by inverting this assembly. A method for manufacturing a battery, comprising: a step of covering the assembly with an outer can while holding the assembly upside down; and a step of tightening the open end of the outer can to the periphery of a sealing packing.