JP3240911B2 - Spiral lithium battery, method of manufacturing the same, and liquid injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

Detailed Description of the Invention The present invention relates to a strip-shaped positive and negative electrodes in a spiral-shaped lithium battery and its manufacturing how having a cell group wound in a spiral shape via a separator.

[0002]

2. Description of the Related Art FIGS. 4A and 4B are process diagrams showing an example of a conventional method for manufacturing a spiral type lithium battery, in which FIG. 4A is a cross-sectional view showing a process for welding a positive electrode lead plate, and FIG. And (c) is a sectional view showing a sealing step.

Conventionally, when manufacturing a spiral-type lithium battery, first, as shown in FIG. 4A, an electrode group 2 is inserted into a negative electrode can 9 and a positive electrode lead led out from the electrode group 2 is inserted. The plate 7 is welded to the positive terminal 12. Then, FIG.
As shown in (b), an electrolytic solution is injected into the negative electrode can 9.
Thereafter, as shown in FIG. 4 (c), the positive electrode terminal plate 12 was fitted into the opening of the negative electrode can 9 together with the sealing gasket 10 while the positive electrode lead plate 7 was bent, so as to be sealed.

[0004]

One method for increasing the output of a spiral lithium battery is to fill a sufficient amount of electrolyte by a vacuum injection method. As described above, the positive electrode terminal portion 12 is attached to the electrode No. 2 before the injection, and this is an obstacle to work, so that it was practically impossible to adopt the vacuum injection method. .

[0005] In order to solve this problem, before and after the process,
A method of attaching the positive electrode terminal portion 12 after performing vacuum injection may be considered, but in this case, the positive electrode lead plate 7 is necessarily welded in the immediate vicinity of the flammable electrolytic solution, so that the welding spark is generated. In addition, there is another problem that the electrolyte may ignite, and the electrolyte may adhere to the welded portion of the positive electrode lead plate 7 at the time of injection, so that it is necessary to wipe the electrolyte. .

Further, when welding the positive electrode lead plate 7 to the positive electrode terminal portion 12, as shown in FIG. 4C, the positive electrode lead plate 7 requires a predetermined length due to restrictions on arrangement, and As a material of the positive electrode lead plate 7, a spiral-type lithium battery is usually made of stainless steel having a higher electric resistance than other metals due to a problem of corrosion resistance. This is an obstacle in increasing the output of the battery. Further, the positive electrode lead plate 7
In order to prevent an internal short-circuit caused by contact with the negative electrode can 9 and the like when the sheet is bent, there is a disadvantage that it is necessary to apply an insulating tape to both surfaces of the positive electrode lead plate 7 to secure insulation.

[0007] The present invention has been made in view of the above circumstances, various inconveniences high output capable of realization spiral type lithium battery and its manufacturing how without accompanied <br/> to provide the above-mentioned With the goal.

That is, the spiral lithium battery of the present invention has a bottomed cylindrical can (9) serving also as one electrode, and a spiral electrode group (2) is inserted into the can. and, wherein the electrolytic solution is impregnated into the can through an insulating sealing gasket (10) to the opening of the can fitted terminal portions of the other electrode (12), said sealing gasket, the central bore To
A stepped annular welded plate (5) is placed in contact with the terminal portion and electrically connected between the welded plate and the other electrode of the electrode group. At least one lead plate (7) is passed through the central hole of the stepped annular welding plate.
Each Te in the form of an upper end portion of the lead plate is welded to the upper surface of the lower portion of the weld plate constituted by vertically on the shortest path.

[0009]

[0010]

[0011]

In the invention of the method for manufacturing a spiral lithium battery according to the present invention, the spirally wound electrode group (2) from which the lead plate (7) is led out has a bottomed cylindrical can (also serving as one electrode). 9), and thereafter, the groove (9a) is formed by peeding at a predetermined position on the opening side of the can, and then the sealing gasket (10) is formed on the groove of the can.
With a central hole inside the sealing gasket.
By placing the welding plate of stepped annular bored (5), before
The upper end of the lead plate is projected from the center hole of the welding plate.
And projecting the lower part of the stepped annular welding plate
The lead plate is welded to the upper surface of the welding plate in this state, and then the electrolyte is injected under vacuum into the can, and then the welding is performed. The terminal part (12) of the other electrode is placed on the upper side of the plate, and finally, the opening of the can is caulked and sealed.

[0013]

[0014]

[0015]

Note that the numbers in parentheses are for convenience showing the corresponding elements in the drawings, and therefore, the present invention is not limited to the description on the drawings. The same applies to the column of “Claims”.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing a method for manufacturing a spiral-type lithium battery according to an embodiment of the present invention, in which (a) is a cross-sectional view showing a beading process of a negative electrode can, and (b) is a mounting process of a sealing gasket. A sectional view showing the
(C) is a sectional view showing a welding process of the positive electrode lead plate, (d)
Is a cross-sectional view showing a step of injecting an electrolytic solution, (e) is a cross-sectional view showing a sealing step, FIG. 2 is a graph showing discharge characteristics of a spiral lithium battery, and FIG. 3 is another embodiment of a spiral lithium battery according to the present invention. FIG. 5 is a cross-sectional view showing an embodiment of the liquid injection device according to the present invention, and FIG. 6 is a cross-sectional view showing a vacuum liquid injection method using the liquid injection device shown in FIG.

Spiral lithium battery 1 according to the present invention
As shown in FIG. 1 (e), a negative electrode can 9 having a cylindrical shape with a bottom has an electrode in which a strip-shaped positive electrode and a negative electrode are spirally wound via a separator. Group 2 is inserted. An electrolytic solution is impregnated in the negative electrode can, and a positive electrode terminal portion 12 is fitted to an opening of the negative electrode can via an insulating sealing gasket 10. Meanwhile, a stepped annular welding plate 5 having a central hole is placed on the sealing gasket so as to abut on the positive electrode terminal portion 12.
Between the welding plate 5 and the positive electrode of the electrode group 2, a lead plate 7 for electrically connecting them is provided in the stepped annular welding plate.
Through the central hole, the upper end of each lead plate
And is suspended on the shortest path in a form that is welded to the upper surface of the .
Further, between the negative electrode can 9 and the negative electrode of the electrode group 2, a negative electrode lead plate (not shown) for electrically connecting them is provided.

Spiral lithium battery 1 according to the present invention
As described above, since the positive electrode lead plate 7 is provided at the shortest distance, the voltage drop loss can be significantly suppressed, and the negative electrode can be attached without attaching an insulating tape to both surfaces of the positive electrode lead plate 7. It is possible to prevent a situation where an internal short circuit occurs due to contact with the can 9 or the like.

In manufacturing the spiral lithium battery 1 according to the present invention, the following procedure is used.

First, as shown in FIG. 1 (a), after inserting the spiral electrode group 2 into the negative electrode can 9, beading is performed at a predetermined position on the opening side of the negative electrode can 9 to form a groove. 9
Form a.

Next, as shown in FIG.
The sealing gasket 10 is placed on the groove 9a, and a stepped annular welding plate 5 is placed inside the sealing gasket 10 as shown in FIG. Then, the positive electrode lead plate 7 derived from the electrode group 2 has a shape protruding upward through the central hole of the welding plate 5.

Thereafter, the upper end of the positive electrode lead plate 7 is bent at a right angle and welded to the lower surface of the welding plate 5.

Next, as shown in FIG. 1D, a sufficient amount of electrolyte is filled in the negative electrode can 9 by a vacuum injection method. To this end, a cup-shaped resin container 21 is placed downward on the upper side of the welding plate 5, and the air in the negative electrode can 9 is exhausted by an exhaust pipe 22.
And the inside of the negative electrode can 9 is evacuated. In this state, the electrolytic solution is injected into the negative electrode can 9 from the injection tube 23. Then, since the inside of the negative electrode can 9 is in a vacuum state, a sufficient amount of the electrolytic solution is quickly filled, and the output of the spiral lithium battery 1 is increased.

When a sufficient amount of the electrolytic solution has been filled in the negative electrode can 9 in this way, the resin container 21 and the like are removed, and as shown in FIG. The terminal portion 12 is placed, and the opening of the negative electrode can 9 is caulked and sealed. At this time, since the upper end of the positive electrode lead plate 7 is welded to the lower surface of the welding plate 5, the positive electrode lead plate 7 does not project upward from the upper surface of the welding plate 5, and Mounting and sealing of the negative electrode can 9 can be performed smoothly. Here, the manufacturing process of the spiral lithium battery 1 is completed.

In order to confirm the above-mentioned effects, the product of the present invention (a single type Li / MnO 2 -based spiral lithium battery manufactured by the above-described method) and a conventional product (a single type lithium-ion battery manufactured by the method shown in FIG. 4) were used. (Li / MnO2 based spiral lithium battery) was subjected to a discharge performance test. The test is-
Under a temperature condition of 20 ° C., 1.9 A, 0.44 s / 0.1
The test was performed under a load of 4 A, 49.56 s.
The result is shown by a graph in FIG. In FIG. 2, the solid line represents the discharge curve of the product of the present invention, and the broken line represents the discharge curve of the conventional product. Note that each of the discharge curves is a curve indicating a voltage at a load of 1.9 A. As is clear from FIG. 2, the battery voltage of the present invention is higher than that of the conventional product, and the battery voltage of the conventional product reaches the cut-off voltage without discharging for 60 hours. The terminal voltage gradually reached after discharging for a time, which indicates that the product of the present invention has better discharge characteristics than the conventional product.

In the above embodiment, as shown in FIG. 1, the spiral lithium battery 1 in which one positive electrode lead plate 7 is provided between the welding plate 5 and the electrode group 2 has been described. In the present invention, the number of the positive electrode lead plates 7 is not limited to one. For example, as shown in FIG. 3, two positive electrode lead plates 7 may be provided between the welding plate 5 and the electrode group 2, or three or more positive electrode lead plates 7 may be provided. When a plurality of positive electrode lead plates 7 are provided, they are formed at substantially equal angular intervals in an annular shape (about 180 ° for two sheets and about 1 ° for three sheets).
(20 °), when each positive electrode lead plate 7 is welded to the welding plate 5, the other positive electrode lead plates 7 do not become an obstacle, so that a smooth welding operation can be performed.

In the above-described embodiment, the spiral lithium battery 1 using the negative electrode can (that is, the can also serving as the negative electrode terminal) has been described. The present invention can be applied when used.

[0029]

In the above embodiment, the container 2
1. A case has been described in which vacuum injection is performed using the exhaust pipe 22 and the injection pipe 23, but the injection apparatus 25 shown in FIG. 5 may be substituted. Hereinafter, the configuration of the liquid injection device 25 and a vacuum liquid injection method using the same will be described.

That is, the liquid injection device 25 has a battery holder 34 as shown in FIG.
A battery sealing jig 26 is provided above and below so as to be movable up and down. On the lower side of the battery sealing jig 26, an annular elastic body 27 made of fluorine-based rubber or the like is mounted, and the battery sealing jig 26 is formed with a liquid injection conduit 26b. As shown in FIG. 6, a connection pipe 31 is connected to the upper side of the battery sealing jig 26 so as to communicate with the liquid injection pipe 26 b, and the connection pipe 31 is provided with a liquid injection cock 32. ing. Further, a liquid storage container 33 is placed above the connecting pipe 31.
An exhaust pipe 26a is formed in the battery sealing jig 26, and a check valve or other check valve 28 is provided in the exhaust pipe 26a. Further, a vent pipe 29 is connected to the battery sealing jig 26 so as to communicate with an exhaust pipe line 26a, and an intake device (not shown) such as a vacuum pump is connected to the vent pipe 29 via a three-way valve 30. Is connected.

When performing vacuum injection using the injection device 25, the negative electrode can 9 is mounted on the battery holder 34, and the battery sealing jig 26 is lowered. Then, the welding plate 5
The elastic body 27 is provided on the upper surface of the
Are closely related. In this state, the cock 32 for liquid injection is rotated by 90 ° by a rotary actuator (not shown) and closed, and then the three-way valve 30 is opened to the vacuum pump side. Then, the air in the negative electrode can 9 is exhausted through the exhaust pipe 26 a of the battery sealing jig 26 and the ventilation pipe 29. Meanwhile, a predetermined amount of the electrolytic solution is injected into the liquid reservoir 33.

When the air inside the negative electrode can 9 is exhausted and reaches a predetermined degree of vacuum (for example, 700 mmHg), the vacuum pump side of the three-way valve 30 is closed and the open side to the atmosphere is opened. Then, the exhaust pipe 26a of the battery sealing jig 26
The inside of the anode can 9 returns to the atmospheric pressure due to the inflow of outside air, but the inside of the negative electrode can 9 remains in a reduced pressure state, so that a pressure difference occurs on both sides of the check ring 28, and the valve body of the check ring 28 is strong in the valve receiver. Pressed.

Next, the injection cock 32 is opened by rotating it by 90 °. Then, the electrolytic solution in the liquid reservoir 33 is injected into the negative electrode can 9 via the connection pipe 31 and the liquid injection pipe 26 b of the battery sealing jig 26. At this time, since the elastic body 27 is in close contact with the upper surface of the welding plate 5 and the inner side surface of the sealing gasket 10, the electrolytic solution does not adhere to the portion above the groove 9a of the negative electrode can 9, and therefore, at the time of sealing. A situation in which the electrolytic solution blows out can be avoided beforehand. As described above, since the check valve 28 is in a state in which the valve element is strongly pressed against the valve element receiver, the electrolyte may enter the exhaust pipe 26a of the battery sealing jig 26. Can reliably be prevented from occurring.

When a predetermined amount of the electrolyte is thus injected into the negative electrode can 9, the injection cock 32 is closed by rotating it by 90 °. Then, the supply of the electrolytic solution is stopped. here,
The vacuum injection step ends.

The opening / closing operation of the injection cock 32 and the three-way valve 30 is performed by one switch using an air timer, and the lifting operation of the battery sealing jig 26 is performed by an air cylinder. By doing so, all operations can be performed using air as a power source, and a compact liquid injection device 25 that does not include electrical equipment can be realized.

In order to confirm the effect of the vacuum injection using the above-described injection device 25, the method of the present invention (the method of performing vacuum injection using the injection device 25) and the conventional method (the method of performing normal pressure injection) are described. For (2), the time required for liquid absorption, the state of blowing out the electrolyte at the time of sealing, and the maximum liquid absorption were compared. The predetermined amount of the electrolyte is 17 g.

As a result, the time required for liquid absorption was 30 minutes in the conventional method, whereas it was 0.1 minute in the method of the present invention.
Minutes or less. In addition, the state of blowing out the electrolytic solution at the time of sealing is 50 out of 200 (ie, 2
5%), whereas no electrolytic solution was blown out in any of the 200 samples in the method of the present invention. Furthermore, the maximum liquid absorption is 1 in the conventional method.
In contrast to 9 g, the method of the present invention weighed 22 g.

As is evident from the test results, the method of the present invention absorbs the liquid more quickly and does not cause the problem of blowing out the electrolytic solution as compared with the conventional method.

As described above, according to the invention of the spiral type lithium battery of the present invention, the spirally wound electrode group 2 having the bottomed cylindrical can also serving as one electrode such as the negative electrode can 9 is formed. Inserted in the can, impregnated with an electrolytic solution in the can, fit the terminal of the other electrode such as the positive electrode terminal 12 through the insulating sealing gasket 10 into the opening of the can, A stepped annular welding plate 5 having a central hole is placed on the sealing gasket so as to be in contact with the terminal portion, and these are placed between the welding plate and the other electrode of the electrode group 2. electrically said stepped one or more lead plates such as a lead plate 7 for connecting the
The upper end of each lead plate passes through the center hole of
Since the welding plate is formed so as to be welded to the upper surface of the lower portion of the welding plate, and is vertically provided on the shortest path, the length of the lead wire connecting the other electrode of the electrode group 2 and the terminal portion is reduced. Therefore, it is possible to minimize the voltage drop loss at the time of discharge, and not only to improve the discharge characteristics especially at the time of large current load, but also to reduce the risk of internal short circuit due to the contact between the lead plate and the can. Since there is no need to attach insulating tape to both sides of the lead plate, the productivity of the spiral lithium battery 1 is increased. Further, the lead plate is placed on the welding plate 5.
Since it does not protrude upward from the step surface, the can can be sealed smoothly.
Can be.

[0041]

[0042]

[0043]

[0044]

In the present invention, the spiral lithium
According to the invention of the battery manufacturing method, the spiral electrode group 2 from which the lead plate such as the positive electrode lead plate 7 is led is inserted into the bottomed cylindrical can 9 also serving as one electrode such as the negative electrode can 9. Thereafter, the groove 9a is formed by performing peding at a predetermined position on the opening side of the can, and then the sealing gasket 10 is placed on the groove 9a of the can, and the inside of the sealing gasket 10 is formed. A stepped annular welding plate 5 having a central hole is placed, and the upper end portion of the lead plate is welded.
Protruding from the central hole of the plate and the protruding part is stepped
Bend so that it contacts the upper surface of the lower part of the annular welded plate
Then, in this state, the lead plate is welded to the upper surface of the welding plate, and then the electrolyte is injected into the can under vacuum,
Thereafter, the terminal portion 12 of the other electrode was placed on the upper side of the welding plate, and finally, the opening of the can was caulked and sealed, so that the length of the lead plate was reduced to the minimum length.
In addition to the fact that the electrolyte is injected after the lead plate has been welded, it is possible to prevent the occurrence of a situation in which the electrolyte is ignited by the sparks of the welding, thus providing excellent safety. In addition, even if the electrolyte adheres to the welded portion of the lead plate at the time of liquid injection, it is not necessary to wipe off the electrolyte. This not only increases the productivity of the spiral-type lithium battery 1 but also provides a sufficient amount of electrolyte by the vacuum liquid injection method. Since the liquid is quickly filled, it is possible to realize a high output of the spiral lithium battery 1.

[0046]

[0047]

[Brief description of the drawings]

FIG. 1 is a process diagram showing a method for manufacturing a spiral-type lithium battery according to one embodiment of the present invention, in which (a) is a cross-sectional view showing a beading process of a negative electrode can, and (b) is a placement of a sealing gasket. FIG. 4C is a cross-sectional view showing a process, FIG. 4C is a cross-sectional view showing a welding process of the positive electrode lead plate, FIG. 4D is a cross-sectional view showing a process of injecting an electrolytic solution, and FIG.

FIG. 2 is a graph showing discharge characteristics of a spiral-type lithium battery.

FIG. 3 is a sectional view showing another embodiment of a spiral lithium battery according to the present invention.

4A and 4B are process diagrams illustrating an example of a conventional method for manufacturing a spiral-type lithium battery, wherein FIG. 4A is a cross-sectional view illustrating a welding process of a positive electrode lead plate, and FIG. (C) is a sectional view showing a sealing step.

FIG. 5 is a cross-sectional view showing one embodiment of a liquid injection device according to the present invention.

FIG. 6 is a cross-sectional view showing a vacuum injection method using the injection apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Spiral lithium battery 2 ... Electrode group 5 ... Weld plate 7 ... Lead plate (positive electrode lead plate) 9 ... Can (negative electrode can) 9a ... Groove 10 ... Sealing gasket 12 ... Terminal ( (Positive electrode terminal portion) 25 ... Liquid injection device 26 ... Battery sealing jig 26a ... Exhaust line 26b ... Liquid injection line 27 ... Elastic body 28 ... Check valve 29 ... Vent tube 30 ... Three-way valve 31 Connection pipe 32 Cock for injection liquid 33 Reservoir container

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Nakada 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (72) Inventor Shuichi Arae 5-36-11, Shimbashi, Minato-ku, Tokyo No. Fuji Electric Chemical Co., Ltd. (72) Inventor Masatake Nishio 5-36-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. (72) Inventor Akihide Izumi 5-36, Shimbashi, Minato-ku, Tokyo No. 11 Inside Fuji Electric Chemical Co., Ltd. (56) References JP-A-1-157706 (JP, A) JP-A-54-85330 (JP, A) JP-A-5-325944 (JP, A) 5-325945 (JP, A) Japanese Utility Model Showa 54-133774 (JP, U) Japanese Utility Model Showa 59-112468 (JP, U) Japanese Utility Model Showa 60-150774 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01M 6/16 H01M 2/22 H01M 2/36 101

Claims (2)

(57) [Claims] 1. A can having a bottomed cylindrical can (9) also serving as one electrode, a spiral electrode group (2) is inserted into the can, and an electrolyte is impregnated in the can. A terminal portion (12) of the other electrode is fitted to the opening of the can via an insulating sealing gasket (10), and a stepped annular welding plate ( 5) is placed in contact with the form to the terminal portion, between the other electrode of the electrode group and the weld plate, the stage these electrically one or more lead plates for connecting (7)
A spiral type lithium battery in which the upper end of each lead plate is vertically welded to the upper surface of the lower portion of the welding plate through the central hole of the attached annular welding plate, and is vertically provided on the shortest path. 2. A bottomed cylindrical can (9) serving as a spiral electrode group (2) from which a lead plate (7) is led out.
After that, the groove (9a) is formed by peeding at a predetermined position on the opening side of the can, and then a sealing gasket (10) is placed on the groove of the can. A stepped annular welding plate (5) having a central hole is placed inside the sealing gasket, and the upper end of the lead plate is placed.
Part projecting from the central hole of the welding plate and its projection
Contact the upper surface of the lower part of the stepped annular welding plate
And in this state, the lead plate is welded to the upper surface of the welding plate. Next, an electrolytic solution is injected into the can under a vacuum state. Electrode terminals (1
2) is mounted, and finally, the opening of the can is caulked and sealed to form a spiral type lithium battery.