JPH0471170A - Manufacture of cylindrical secondary battery - Google Patents

Abstract

PURPOSE:To enhance the operating easiness and decrease the manufacturing loss by coupling a band-shaped separator with a pipe-shaped insulation before or after fitting this on the rotary supporting shaft of a winding device. CONSTITUTION:A band-shaped separator 3 is coupled with a pipe-shaped insulation 1 before or after fitting it on the rotary supporting shaft 2b of a winding device 2. The insulation 1 is fitted on the rotary supporting shaft 2b of winding device 2. A band-shaped pos. electrode plate 5 and a neg. electrode plate 6 are pinched by this separator 3 folded into two parts, and the whole laminate is held to provide a set 7 of band-shaped electrode plates, which is wound by rotating the rotary supporting shaft 2b. Then this set 7 of electrode plates is drawn off from the shaft 2b together with the insulation 1. This electrode set 7 with insulation 1 is accommodated in a cylindrical, small-sized metal vessel 8. An electrode rod 10 is inserted into a hole 1a and pressed to the oversurface of a tab 6a on the neg. electrode plate 6, and spot welding is applied to the bottom wall surface 8a.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a cylindrical secondary battery.

[Conventional technology]

A conventional method for manufacturing a cylindrical secondary battery is generally performed as follows.

That is, first, a group of wound electrode plates to be housed in a cylindrical metal container is prepared as follows. That is, the strip-shaped separator is inserted as it is or folded in half into a split bottle-shaped winding shaft provided in a winding device, through a slit formed between the split bottles, and the insertion portion is held between split pins. in a state of
The winding shaft is rotated and wound around the winding shaft in a J-shape.The band-shaped positive electrode plate and the belt-shaped negative electrode plate are superimposed on each other through the separator that is held on the winding shaft. The 0th order rotates and uses this as the winding core to form a wound electrode group.
After pulling out the wound electrode plate group from the split pin, it is stored in a cylindrical metal container, and the lug of the negative electrode plate of the wound electrode plate group is spot welded to the bottom wall of the container. A secondary battery was manufactured by inserting the electrode into the hollow hole at the center of the wound electrode group, pressing it against the negative electrode lug, and spot welding it to the bottom wall surface.

[Problem to be solved by the invention]

However, in the above-mentioned conventional manufacturing method of a cylindrical secondary battery, when producing a wound electrode plate group, as described above, a separator is inserted into a slit of a split bottle-shaped winding shaft of a winding device.
Then, the winding shaft is rotated and wound around the winding shaft in the shape of a "2" shape.Then, in the work of pulling out the wound electrode plate group formed by winding this as the winding core, from the split pin. , the center separator part that is wrapped around the cotter-shaped winding core in a J-shape is caught by the cotter pin.
This makes it difficult to remove. Also, if you try to pull it out forcibly, it will not only cause the wound electrode plate to be pulled out from the center, resulting in inconveniences such as not being able to store it in the container, but even if it can be pulled out safely, After storing the wound electrode plate group in a container, the electrode rod is inserted into the hollow hole in the center of the wound electrode plate group, and the hollow hole is As mentioned above, since the slit insertion part of the separator protrudes into the circular hole, that is, it has a "" shape, when the electrode rod is inserted, it is difficult for the electrode rod to get caught in it. This poses problems such as making it difficult to insert the electrode rod or interfering with the pressure contact of the electrode rod with the negative electrode lug, resulting in poor biting or spotting, resulting in manufacturing loss or product defects.

The tendency for the above disadvantages to occur increases as the diameter of the hollow hole at the center of the wound electrode plate becomes smaller, and is particularly noticeable in the production of small cylindrical secondary batteries.

[Means to solve the problem]

The present invention solves the disadvantages of the conventional method for manufacturing cylindrical secondary batteries, and provides a method for manufacturing cylindrical secondary batteries that smoothly and easily produces good products without production loss. A band-shaped separator is attached to the body before or after it is fitted to the rotation support shaft of the winding device, and then, with the pipe-shaped insulator fitted to the rotation support shaft, forming a wound electrode plate group by rotating the rotary support shaft and winding the pipe-shaped insulator as a winding core; The obtained wound electrode plate group is pulled out from the rotating support shaft together with the core of the pipe-shaped insulator, and then, after storing it in a cylindrical metal container, the electrode rod is inserted into the pipe-shaped insulator. It is characterized in that it is inserted into a hollow hole, pressed against a negative electrode lug that overlaps the bottom wall surface of the container, and is spot welded to the bottom wall surface.

[For production]

The band-shaped separator is tied to the pipe-shaped insulator before or after it is fitted to the rotation support shaft of the winding device, so that the support shaft can be removed from the state in which it is fitted to the rotation support shaft. When it rotates, the pipe-shaped insulator also rotates, and the band-shaped electrode group is wound around the pipe-shaped insulator as a winding core. Since the wound electrode plate group is pulled out along with the pipe-shaped insulator from its rotating support shaft, it is possible to easily and smoothly pull out the #t1 electrode plate group in its predetermined wound state, and the center A pipe-like insulator is provided in the pipe-shaped insulator. Therefore, a wound electrode plate group having a circular hollow hole secured by the pipe-shaped insulator at its center is obtained.

Next, when this is housed in a cylindrical metal container, the circular hollow hole is secured in the center. Therefore, it is always advisable to then insert the electrode rod into the circular hollow hole in its center and press it directly against the lug of the negative electrode plate superimposed on the bottom wall of the container to spot weld it to the bottom wall. can be done accurately,
It improves work efficiency and makes it possible to manufacture good cylindrical secondary batteries without production loss.

In this case, it is common to bond the intermediate portion of the belt-shaped separator to the pipe-shaped insulator, which is preferred because it allows easy formation of a belt-shaped separator that is bent at the intermediate portion.

Further, it is preferable that the pipe-shaped insulator is made of a thermoplastic synthetic resin and the thermoplastic resin separator is heat-sealed because a strong bond between the two can be easily and quickly obtained.

Further, when the pipe-shaped insulator is fitted onto the rotation support shaft of the rotation device, and the slit provided at at least one end of the pipe-shaped insulator is fitted and locked to the engagement protrusion provided on the winding device side, This is preferable because the pipe-shaped insulator can be fitted onto the rotation support shaft and rotated integrally in the rotation direction.

〔Example〕

The present invention can be applied to cylindrical secondary batteries such as cylindrical alkaline storage batteries and cylindrical lithium secondary batteries, regardless of their size, and is applicable to consumer electronic devices such as memory backup devices: f It is particularly advantageous for manufacturing small cylindrical secondary batteries such as IJH-2, UN-3, and υH-4. Next, an embodiment of the present invention will be described with reference to the accompanying drawings regarding a method for manufacturing a small cylindrical lithium secondary battery.

In the drawing, 1 shows an example of a pipe-shaped insulator used in the manufacturing method of the present invention. The pipe insulator 1 is preferably made of a thermoplastic synthetic resin such as polypropylene. It can be obtained with high efficiency by forming it into a long pipe-like object and then cutting it into a predetermined size. The illustrated example is a thin-walled polypropylene molded body with an outer diameter of 2.5 cm, an inner diameter of 1 cm, and a length of 405 w+.

According to the present invention, a winding device 2 used in the manufacturing method of the present invention as shown in the second figure is separately prepared.

The winding device 2 consists of a motor 2a and a rotary support shaft 2b rotated by the motor 2a, and further comprises a cylindrical set member 2C fitted onto the tip of the rotary support shaft 2b. The rotary support shaft 2b is usually a circular shaft having approximately the same diameter as the circular hollow hole 1a of the pipe-shaped insulator 1, and is preferably formed so that the pipe-shaped insulator 1 is fitted thereto by T degrees. Generally, its length is sufficient to fit the pipe-shaped insulator 1 and the set member 2C.

According to the present invention, the strip separator 3 is bonded to the pipe-like insulator 1 before or after the pipe-like insulator 1 is fitted onto the rotation support shaft 2b of the winding device 2.

FIG. 3 shows an example in which the band-shaped separator 3 is bonded to the pipe-shaped insulator 1 before it is fitted onto the rotary support shaft 2b. 4 indicates a bonding portion. The strip separator 3
Generally, the intermediate portion of the pipe-shaped insulator 1 is bonded to the pipe-shaped insulator 1. In the example shown in the third figure, after the middle part of the band-shaped separator 3 is wrapped around the pipe-shaped insulator 1, the winding is tied 4 at the middle part. After folding, the folded portion may be overlapped with the band-shaped separator 3, and this overlapping portion may be bound.

Although the bonding may be performed using an adhesive, it is possible to obtain highly efficient and strong bonding by thermal fusion. The band-shaped separator 3 can be made of any electrical insulating material in the form of a film, woven fabric, non-woven fabric, etc., but for bonding by heat fusion, it is sufficient that it is made of thermoplastic synthetic resin; Here, a porous thermoplastic synthetic resin strip separator 3 made of a nonwoven fabric of thermoplastic synthetic fibers such as polypropylene fibers is used, and this is heat-sealed to the pipe-shaped insulator 1. Heat fusion is performed by applying a hot plate, electric iron, or the like to the overlapping portion. In this case, as shown in the example shown in the figure, it is common and preferable to form a linear binding 4 over the entire width of the separator 3. For example, the band-like separator 3 shown in the drawing has a width of 42cm and a length of 400m+. I used the one from

In this way, the pipe-shaped insulator 1 with the band-shaped separator 3 bound thereto is then folded into two at the sixth position to be fitted onto the rotation support shaft 2b of the winding device 2, as shown in the fourth figure. The width of the upper separator of the strip separator 3 is 40 mm.
A strip positive electrode plate 5 with a width of 40 m and a length of 200 ff is placed on the bottom surface of the positive electrode plate 5 with a width of 40 m and a length of 200 ff with a lower separator.
The iI+ band-shaped negative electrode plate 6 is sandwiched and superposed to hold the whole, and the thus obtained band-shaped electrode plate group 7 is rotated along the rotating support shaft 2b by driving the motor 2a of the winding device 2. Rotate in the direction shown to perform winding work.

In this case, the pipe-shaped insulator 1 fitted therein rotates with the rotation of the support shaft 2b, and thus the band-shaped electrode plate group is wound around the pipe-shaped insulator 1 as a winding core. Thus, the wound electrode plate group 7 is obtained. After fitting the pipe-shaped insulation #1 to the rotary support #H1, the set member 2C is fitted to the tip of the support shaft 1b through the fitting shaft hole 2c1 at the center, and the pipe It is common to set the shaped insulator 1 in a predetermined position. Further, since the diameter of the cylindrical set member 2C is equal to or larger than the diameter of the wound electrode plate group to be formed, the winding of the wound electrode plate group can be performed correctly and well. In the drawings, reference numeral 58 indicates a lug protruding from the I-shaped positive electrode plate 5, and 6a indicates a lug protruding from the strip-shaped negative electrode plate 6.

Next, according to the present invention, the thus formed wound electrode plate group 7 is pulled out from the rotation support shaft 2b together with the pipe-shaped insulator 1. In this case, the wound electrode plate group 7 formed in this manner is simply fitted onto the rotation support shaft 2b. It is easy to pull out the pipe-shaped insulator 1, which is located at the center of the insulator 1, while the wound electrode group 7 on the outer periphery is removed from the center of the wound electrode group when conventional split pins are used. There is no fear of slippage, and it can be pulled out in its predetermined wound state.

Moreover, since the pulled-out wound electrode plate group 7 has the pipe-shaped insulation #1 on its inner peripheral surface, a circular hollow hole 1a is secured at its center.

Next, the thus obtained wound electrode plate group 7 with the pipe-shaped insulator 1 is housed in a small cylindrical metal container 8 suitable for tightly fitting housing, as shown in FIG. To house it, as in the conventional method, the lug 6a of the negative electrode plate 6 passes through an insulating sheet 9 having a center hole placed on the lower surface of the wound electrode plate group 7, and then is bent. The metal container 8 is exposed to the lower end surface of the circular hollow hole 1a, and the metal container 8
The polymers are brought out in a polymerized state on the bottom wall surface 8a of the container.

Next, the electrode rod 10 is inserted into the circular hollow hole 1a, pressed against the upper surface of the lug 6a of the negative electrode plate 6, and spot welded to the bottom wall surface 8a. Thus, the method for manufacturing a cylindrical secondary battery of the present invention is completed. Although not shown, pouring the electrolyte into the container 8, closing it with the lid, and connecting the lug 6a of the positive electrode plate 6 to the anode terminal post provided on the lid are performed in the same manner as in the conventional method. be exposed.

According to the present invention, the above-mentioned spot welding operation is carried out because a circular hollow hole 1a is secured at the center of the wound electrode plate group 7 housed in the metal container 8 by the pipe-shaped insulator 1. The electrode rod 10 can be inserted smoothly and easily, and the spot welding of the ears 6a superimposed on the bottom wall surface 8a of the metal container 8 can always be performed reliably, making it possible to manufacture good secondary batteries without product defects. . Therefore, it is particularly advantageous for manufacturing small cylindrical secondary batteries such as U-2, 0M-3, and UN-4, in which the hollow holes in the wound electrode plate group are extremely small.

Furthermore, in the work of the wound electrode plate group in the manufacturing method of the present invention, as shown in the first figure, an engagement slit 1b is provided at at least one end of the pipe-shaped insulator 1, and this is inserted into the pipe-shaped insulator 1. is preferably fitted onto the rotation support shaft 2b of the winding device W2, and its engaging slit 1b is fitted and locked to the engaging protrusion 12 provided on the winding device 2 side. In this case, the setting state of the pipe-shaped insulator 1 with respect to the rotation support shaft 2b becomes even better, and
The integral rotation of both in the rotation direction becomes even better.

In the example of FIGS. 1 and 2, the tube-shaped insulator 1 is
a pair of engagement slits 1b in the radial direction at both ends thereof;
1b and 111.1b, and on the winding device 2 side, as shown in the third figure, a base end of the rotation support shaft 2b is provided.
A pair of engagement protrusions 12.12 are arranged in the radial direction, and a pair of engagement protrusions 12.12 are arranged in the radial direction of the shaft hole 2c1 on the inner wall surface of the center member 2C. Therefore, when the pipe-shaped insulator 1 is mounted on the rotation support shaft 2b, the winding device 2 is inserted into each pair of slits 1b, Ib at both ends of the pipe-shaped insulator 1.
When fitting and locking the protrusions 12 and 12 on each pair of side ends, the pipe-shaped insulator 1 must be stably and integrally fitted to the rotation support shaft 2b. I can do it.

Next, the effects of the manufacturing method of the present invention will be clarified through a comparative test between an example when applied to a small cylindrical lithium battery and a conventional manufacturing example.

A pipe with a width of 421 m,
The middle part of a separator made of microporous polypropylene film with a length of 400 mm is bent and wrapped, and the winding is done in a zero-order manner by pressing a wide hot plate against the part and bonding the two by heat fusion. The pipe-shaped insulator with the separator bound as shown above is fitted onto the rotation support shaft of the #@ rotation device, and a strip-shaped positive electrode plate with a width of 40 m and a length of 200 fi is placed on the upper surface of the separator, and a strip-shaped positive electrode plate with a width of 40 mm is placed on the lower surface of the separator. , a strip-shaped negative electrode plate having a length of 200 m is polymerized to form a strip-shaped electrode plate group, and this is rotated about the rotation support shaft to form a wound electrode plate group.
Next, by pulling this together with the pipe-shaped insulator from the rotation support shaft, a pipe-shaped insulator is provided in the center,
Therefore, the wound electrode plate group of the present invention is obtained which has a circular hollow hole of the pipe-shaped insulator at its center.

The strip-shaped negative electrode plate has a thickness of O, 'L as the negative electrode active material.
A material made of AS lithium foil with a stainless steel negative electrode lug crimped onto the 1111 edge in the length direction was used. The strip-shaped positive electrode plate is prepared by mixing an oxide such as Hn02 as a positive electrode active material, Ketchen Black as a conductive agent, and Polyflon powder as a binder at a predetermined mixing ratio, and processing the mixture into a sheet shape, which is made of stainless steel. It is made by sandwiching steel expanded metal from both sides and crimping it with a roll press to form a positive electrode sheet, which is then cut to the above dimensions.A stainless steel positive electrode lug is spot welded to the other longitudinal edge of the positive electrode sheet. I used what was provided.

By the method of the present invention described above, samples of 100 wound electrode plate groups were produced. In all samples, no slippage of the wound electrode plate group was observed.

For comparison, a split bottle-shaped winding core with slits of a conventional winding device was used, and the middle bent part of the band-shaped separator was inserted into the slit and wound around it, and then the band-shaped positive electrode plate was wrapped around it. 100 samples were obtained by polymerizing a strip-shaped negative electrode plate, winding the strip-shaped electrode plate group, and pulling it out from the cotter pin at the zeroth order that formed the wound electrode plate group. Out of the 100 pieces, the number of deviations in the wound electrode plate group is
11 cases occurred.

Next, for each of the 100 wound electrode plate group samples equipped with a pipe-shaped insulator produced according to the present invention and having a circular hollow hole in the center, a small cylindrical shape of 11M-3 type was prepared. It was housed in a cylindrical steel metal container for lithium batteries, and the electrode rod was inserted into the circular hollow hole, pressed against the lug of the negative electrode plate against the bottom wall of the container, and spot welded to the bottom wall. In this welding work, no defective insertion of the scraper or defective spot welding was observed.

For comparison, we selected 100 rolled electrode plates that had been obtained using the conventional method described above without any slippage, and placed them in the same small steel metal containers as above, and used the same electrode rods. Then, this was inserted into the hollow hole in the shape of a "no" in the center, and the negative electrode lug was spot welded. Six rods were incorrectly inserted. Furthermore, out of 100 lithium batteries that were completed, 4 had defective spot welding.

As described above, according to the manufacturing method of the present invention, a small cylindrical lithium secondary battery can be manufactured smoothly and easily without manufacturing loss, whereas in the conventional method, as described above, a considerable amount of winding is required. This resulted in defective polarizer plates and manufacturing losses.

Furthermore, similar results were obtained when an alkaline storage battery was manufactured instead of a lithium secondary battery.

The means for attaching the strip separator to the pipe-shaped insulator after it has been fitted onto the rotary support shaft is the same as that before fitting, and there is no need to describe it in detail.

As described above, according to the present invention, a pipe-shaped insulator is prepared, and a band-shaped separator is bonded to it before or after fitting it onto the rotation support shaft of the winding device.
When rotating the rotation support shaft, a band-shaped electrode plate group formed by superposing a band-shaped positive electrode plate and a band-shaped negative electrode plate via the band-shaped separator bonded to a pipe-shaped insulator fitted to the rotation support shaft, Along with this, the pipe-shaped insulator is moved, so that a wound electrode plate group can be formed around it using this as a winding core. When pulling out the entire insulator from the rotary support shaft, the wound electrode plate is always well-wound without damaging the winding condition of the group of wound electrode plates and without causing displacement of the center. Groups can be separated. At the same time, since the central part of the wound electrode plate group has the pipe-shaped insulator, it is then housed in a cylindrical metal container, and then the electrode rod is inserted into the hollow of the pipe-shaped insulator. Since the lugs of the polymerized negative electrode plate are spot-welded to the bottom wall surface of the container through the holes, the lugs can always be firmly spot-welded to the bottom wall surface of the container smoothly and reliably. This has the effect of solving the conventional problems such as difficulty in inserting the electrode rod into the hollow hole in the center of the wound electrode plate group and defective spot welding.

In the above manufacturing method of the present invention, when the intermediate portion of the strip separator is bound to the separator,
It is preferable to have the separator divided into two pieces, upper and lower, in the middle because it can be easily obtained.

In addition, if the pipe-shaped insulator is made of thermoplastic resin and the strip-shaped separator is a thermoplastic separator, and the two are thermally fused, the bonding process can be made easier and faster, and a strong bond can be obtained. You can wear clothes.

Furthermore, the pipe-shaped insulator is provided with an engagement slit at at least one end thereof, and when the pipe-shaped insulator is fitted onto the rotation support shaft, the slit is fitted and locked into the engagement protrusion provided on the winding device side. When tightening, the fitted state is strengthened, mutual integral connection in the direction of rotation is ensured, and the effect of improving the integral rotation of the two is brought about.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an example of a pipe-shaped insulator used in the manufacturing method of the present invention, FIG. 2 is an exploded perspective view of an example of a winding device used in the manufacturing method of the present invention, and FIG. The figure is a perspective view of one example of the manufacturing process of the present invention, FIG. 4 is a perspective view of the winding process of a band-shaped electrode plate group, and FIG. 5 is a cylindrical secondary battery containing the wound electrode plate group. FIG. 3 shows a vertical cross-sectional view of a spot welding process for ears on a container. 1... Pipe-shaped insulator 1a... Hollow hole, circular hollow hole 1b... Engagement slit 2... Winding device 2a...
・Motor 2b...Rotation support shaft 2C...Set member 3...Band-shaped separator 4...Binding part 5...Band-shaped positive electrode plate 5a...Lug
6... Band-shaped negative electrode plate 6a... Ledge 7... Band-shaped electrode plate group, wound electrode plate group 8... Cylindrical metal container 8a... Bottom wall surface 10...
Electrode rod 12...Locking protrusion Figure 3

Claims (1)

[Claims] 1. A strip separator is attached to the pipe-shaped insulator before or after it is fitted to the rotation support shaft of the winding device, and then the pipe-shaped insulator is attached to the rotation support shaft of the winding device. A band-shaped electrode plate group consisting of a band-shaped positive electrode plate and a band-shaped negative electrode plate are overlapped with each other via this while the band-shaped positive electrode plate and the band-shaped negative electrode plate are overlapped with each other is wound by rotating the rotating support shaft and using the pipe-shaped insulator as a winding core. forming a wound electrode plate group, pulling out the obtained wound electrode plate group together with the core of the pipe-shaped insulator from the rotating support shaft, and then housing it in a cylindrical metal container. After that, an electrode rod is inserted into the hollow hole of the pipe-shaped insulator and pressed against the negative electrode lug that is superposed on the bottom wall surface of the container, and the electrode rod is spot welded to the bottom wall surface. manufacturing method. 2. The method for manufacturing a cylindrical secondary battery according to claim 1, wherein the intermediate portion of the strip separator is bonded to the pipe-shaped insulator. 3. The pipe-shaped insulator is made of thermoplastic synthetic resin,
3. The method for manufacturing a cylindrical secondary battery according to claim 1, further comprising heat-sealing a thermoplastic synthetic resin separator thereto. 4. Fitting the pipe-shaped insulator onto the rotation support shaft of the winding device, and fitting a slit provided at at least one end of the pipe-shaped insulator into an engaging protrusion provided on the winding device side. The method for manufacturing a cylindrical secondary battery according to claim 1, 2 or 3, wherein the cylindrical secondary battery is locked.