JP2001155710A - Storage battery and method of fabricating it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage battery of high discharge capacity by means of an electricity collection part with a large cross section and short length for welding the sealing member and collector. SOLUTION: A storage battery comprises a battery case 16 with an opening serving as one of the positive and negative electrodes terminal, sealing member 17 serving as the other electrode terminal for sealing the opening of the case, electrode assembly 10 made of positive and negative electrode plates 11 and 12 mounted in the case 16 with the collector 14 connected to at least one end the positive and negative electrodes 11 and 12. The sealing member 17 and the collector 14 are connected with a lead member consisting of a drum-like part 20 with the central part of the periphery being concave. The upper and lower ends of drum-like part are provided with blades 22 and 23 having large width part 22a, 23a and small width parts 22b, and 23b alternately arranged, so that the large width part 22a faces the small width part 23b with a gap between them, and the small width part 22b faces the large width part 23a with a gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery case having an opening serving also as a terminal of one pole, a sealing body sealing the opening and serving as a terminal of the other pole, and a positive electrode housed in the battery case. The present invention relates to a storage battery including an electrode body having a current collector connected to at least one end of a negative electrode and a method for manufacturing the same, and in particular, a current collector and a sealing body connected to at least one of a positive electrode and a negative electrode. The present invention relates to an improvement in a current collecting structure of a lead portion to be connected and a welding method thereof.

[0002]

2. Description of the Related Art Generally, an alkaline storage battery such as a nickel hydride storage battery or a nickel-cadmium storage battery has a separator interposed between a positive electrode and a negative electrode, and spirally winds them. A current collector is connected to the battery body to form an electrode body. The electrode body is housed in a metal battery case, and a lead extending from the current collector is welded to a sealing body. It is hermetically sealed by mounting it with an insulating gasket in between.

[0003] When such an alkaline storage battery is used for charging and discharging at a high rate, such as an electric tool or an electric vehicle, a lead portion connecting between a current collector and a sealing body is particularly used in a battery configuration. Has a significant effect on battery characteristics. That is, when the electric resistance at the lead portion is large, when a discharge is performed with a large current, a large voltage drop due to the electric resistance at the lead portion occurs, causing a problem that the battery voltage decreases. In view of this, Japanese Patent No. 2762599 proposes that a lead portion is formed by using a plurality of current collecting components, or that the thickness of the current collecting component is increased to reduce the electrical resistance at the lead portion. Became.

[0004]

In the case where a plurality of current collecting parts are included in the lead part, the number of parts is increased and the lead part is not flexible, so that it is difficult to weld the lead part. In addition, when the sealing body is sealed by caulking the opening of the battery case, it is difficult to bend the lead portion, resulting in a problem that productivity is deteriorated. In addition, if the thickness of the current collecting component constituting the lead portion is increased,
Ineffective welding current for resistance welding increases and the weldability with the sealing body deteriorates, and it is difficult to bend the lead part when sealing the sealing body with the opening of the battery case closed. As a result, there was a problem that productivity was poor.

On the other hand, when welding a lead portion to a sealing body,
The sealing body is placed adjacent to the lead that rises vertically from the current collector, the welding electrode is pressed against the side of the lead, and the lead is resistance-welded to the sealing body. It is attached to the opening, and the end of the opening is caulked to seal. Generally, when a lead portion having a large thickness and a short length is used, the specific resistance is reduced and the internal resistance of the battery is reduced.

However, as described above, after the lead is welded to the sealing body, in order to attach the sealing body to the opening of the battery case, a long lead is used.
At the time of sealing, it is necessary to attach the sealing body to the opening of the battery case by bending the lead. For this reason, the length of the lead must be at least as long as the radius of the electrode body, and in order to bend the lead, a thin and long lead must be used. There is a problem that the specific resistance increases and the internal resistance of the battery increases.

In general, the resistance of a current collecting component is inversely proportional to its cross-sectional area in proportion to its length. Therefore, it is necessary to increase the cross-sectional area in order to reduce the resistance of the current collecting component. However, a plate-shaped body is usually used as the current collecting component. When a plate is used as a current collecting component, the maximum width of a cylindrical battery is limited by the diameter of the battery, and the maximum cross-sectional area of the current collecting component is limited. There was a limit to the reduction.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a current collecting component which can reliably weld a sealing body and a current collector even if the sectional area is large and the length is short. A first object of the present invention is to obtain a storage battery having excellent high-rate discharge performance. It is a second object of the present invention to provide a welding method capable of reliably welding a sealing body and a current collector using such a current collecting component.

[0009]

In order to achieve the first object, the storage battery of the present invention comprises a sealing member and a current collector, each of which has a drum-shaped cylinder having a concave central portion in a longitudinal direction. It is fixedly connected by a lead portion composed of a body. By using the lead portion composed of such a drum-shaped tubular body, the cross-sectional area of the lead portion (the length of the circumference of the tubular body × the thickness of the base material of the tubular body) increases, and the length of the lead portion also increases. Since the length can be shortened, the resistance at the lead portion is reduced. As a result, a storage battery with reduced internal resistance and high output characteristics can be obtained.

When the lead portion is formed of a drum-shaped cylinder having a concave central portion in the longitudinal direction, the circumferential length of the cylinder is longer than the width of the lead portion formed of a plate-shaped body. Therefore, the cross-sectional area required by the lead can be easily secured, and the thickness of the base material of the cylindrical body can be made smaller than the thickness of the lead made of the plate-like body. . For this reason, welding with the sealing body or the current collector becomes easy, and since the central part is formed in a concave drum shape, it is easy to caulk the sealing body into the opening of the battery case and seal it. As a result, the production of this type of storage battery becomes easy.

[0011] Since this type of lead is fixedly connected to the lower surface of the sealing body or the upper surface of the current collector by resistance welding, the lead needs to have a shape and structure in which welding electrodes can be easily arranged. For this reason, the lead of the present invention is provided with a flange in which wide portions and narrow portions are alternately formed at the upper and lower ends of the drum-shaped tubular body, and the width of the wide portion of the upper flange and the width of the lower flange. The narrow portion overlaps with each other across the space, and the narrow portion of the upper flange and the wide portion of the lower flange overlap with each other across the space. As a result, the wide portion of the flange portion becomes a welded portion with the lower surface of the sealing body or the upper surface of the current collector, and the welding electrode can be arranged on the outer peripheral portion of the narrow portion of the flange portion. For this reason, welding of the wide portion of the lower end flange portion of the drum-shaped cylinder and the current collector or welding work of the wide portion of the upper flange portion of the drum-shaped cylinder and the lower surface of the sealing body becomes easy, and this type of storage battery The production becomes easier and the workability is improved.

Further, in order to firmly connect the lead portion to the lower surface of the sealing body or the upper surface of the current collector by resistance welding, it is necessary to concentrate the welding current on the welded portion. When small projections are formed on the upper surface of the wide portion or the lower surface of the wide portion of the lower flange, the welding current concentrates on these small projections, and the lead portion and the lower surface of the sealing body or the current collector are formed. The upper surface is firmly fixedly connected to the upper surface by resistance welding.

According to a second aspect of the present invention, there is provided a method of manufacturing a storage battery according to the present invention, wherein a lead portion comprising a drum-shaped cylindrical body having a concave central portion in a longitudinal direction is provided on a top surface of a current collector. A first welding step of welding to one of the lower surfaces of the sealing body, an electrolyte injecting step of injecting the electrolyte into the battery case, an arranging step of arranging the sealing body at the opening of the battery case, A sealing step of sealing the opening of the battery case, and a second welding step of passing a current between the battery case and the sealing body to weld the lead to one of the lower surface of the sealing body and the upper surface of the current collector. Is provided.

As described above, after the first welding step of welding the lead portion composed of the drum-shaped cylindrical body having a concave central portion in the longitudinal direction to either the upper surface of the current collector or the lower surface of the sealing body. After injecting the electrolyte into the battery case, sealing the opening of the battery case with the sealing body, and applying a voltage between the battery case and the sealing body, the sealing body → lead → collector → positive Since the current flows through the path from the negative electrode to the battery case or the reverse path (second welding step), it is necessary to weld the lead portion to either the lower surface of the sealing body or the upper surface of the current collector. become able to.

In this case, if the gap between the sealing member and the lead portion and the gap between the lead portion and the current collector are not in close contact, a phenomenon occurs in which the molten metal is scattered, so-called "welding dust" occurs. This is one of the causes of a battery short circuit. For this reason, in the sealing process, the sealing body is pressed against the drum-shaped tubular body so as to be crushed around the center in the length direction of the drum-shaped tubular body,
It is necessary to make tight contact between the sealing member and the lead portion and between the lead portion and the current collector.

Further, in the method of manufacturing a storage battery according to the present invention, a lead portion formed of a drum-shaped cylindrical body having a concave central portion in a longitudinal direction is welded to one of an upper surface of a current collector and a lower surface of a sealing body. A first welding step, an electrolyte injecting step of injecting an electrolyte into the battery case, and sealing the opening of the battery case so that the sealing body is in contact with the lead or the lead and the current collector. An arranging step of arranging the body, a second welding step of flowing a current between the battery case and the sealing body to weld the lead portion to either the lower surface of the sealing body or the upper surface of the current collector, And a sealing step of sealing the opening in the battery case.

As described above, even if the sealing step of sealing the sealing member to the opening of the battery case is performed after the second welding step, the voltage between the battery case and the sealing member in the second welding step may be increased. Is applied, the sealing member and the lead portion or the lead portion and the current collector are in contact with each other, so that the sealing member → lead portion → current collector → positive / negative electrode → battery case path,
Alternatively, the current flows through the reverse path, so that the lead portion can be welded to either the lower surface of the sealing body or the upper surface of the current collector. Thereafter, in a sealing step, the battery can be formed by sealing the sealing body to the opening of the battery case.

In this case, if the sealing member and the lead portion and the lead portion and the current collector are not in close contact with each other, a phenomenon occurs in which the molten metal is scattered and a battery short circuit occurs.
In the second welding step, the sealing body is pressed against the drum-shaped tubular body so as to be crushed around the center in the longitudinal direction of the drum-shaped tubular body, and a current is caused to flow between the battery case and the sealed body. Then, it is necessary to bring the sealing member and the lead portion into close contact with each other and the lead portion with the current collector.

The upper and lower ends of the drum-shaped tubular body are provided with flanges in which wide portions and narrow portions are formed alternately, and the wide portions of the upper end flange and the width of the lower end flange of the drum-shaped tubular body are provided. The narrow portion overlaps each other across the space, and the narrow portion of the upper end flange portion and the wide portion of the lower end flange portion of the drum-shaped tubular body are arranged so as to overlap each other across the space. A welding electrode is arranged on the outer periphery of the narrow portion of the portion, and the wide portion of the lower flange is welded to the upper surface of the current collector, or a welding electrode is arranged on the outer periphery of the narrow portion of the lower flange. Then, if the wide portion of the upper flange portion and the lower surface of the sealing body are welded, the welding electrode can be arranged on the outer peripheral portion of the narrow portion of the upper flange portion of the drum-shaped tubular body,
The work at the time of welding the wide part of the lower end flange portion of the drum-shaped tubular body and the current collector is facilitated, so that this type of storage battery is easily manufactured and workability is improved.

In order to firmly connect the lead to the lower surface of the sealing body or the upper surface of the current collector in the above-mentioned second welding, it is necessary to concentrate the welding current on the weld. For this reason, it is necessary to form a small protrusion on at least one of the upper surface of the wide portion of the upper flange or the lower surface of the wide portion of the lower flange, and concentrate the welding current on the small protrusion.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a nickel-hydrogen storage battery will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a state in which a drum-shaped tubular body constituting a lead portion of the present invention is welded to a positive electrode current collector and a sealing body. FIG. 2 is a cross-sectional view showing a state in which the electrode body is inserted into the battery case and the drum-shaped tubular body and the sealing body are welded. Further, FIG. 3 is a view showing a main part of a state in which a drum-shaped tubular body is welded to the upper part of the positive electrode current collector of the electrode body, FIG. 3 (a) shows a top view thereof, and FIG. FIG. 3C is a side view, and FIG. 3C is a cross-sectional view taken along the line AA in FIG. FIG. 4 is a cross-sectional view showing a state where a plate-like body constituting a lead portion of a comparative example is welded to a positive electrode current collector and a sealing body.

1. Electrode body The nickel-hydrogen storage battery of the present embodiment is a nickel positive electrode plate 1
1 and a hydrogen storage alloy negative electrode plate 12. The nickel positive electrode plate 11 is formed by forming a nickel sintered porous body on the surface of an electrode core made of punched metal, and then filling the nickel sintered porous body with an active material mainly composed of nickel hydroxide by a chemical impregnation method. Have been made. On the other hand, the hydrogen-absorbing alloy negative electrode plate 12 is prepared by filling a paste-like negative-electrode active material made of a hydrogen-absorbing alloy on the surface of an electrode plate core made of punching metal, drying it, and rolling it to a predetermined thickness. Have been.

A spiral electrode group was formed by spirally winding the nickel positive electrode plate 11 and the hydrogen storage alloy negative electrode plate 12 with a separator 13 interposed therebetween. At the upper end surface of the spiral electrode group, an end portion 11a of a punching metal which is an electrode core of the nickel positive electrode plate 11 is exposed, and at the lower end surface, an electrode plate core of the hydrogen storage alloy negative electrode plate 12 is provided. An end 12a of a certain punching metal is exposed. A large number of openings 1 are formed in the positive electrode core exposed at the upper end surface of the spiral electrode group.
4a, 14a... And a liquid injection opening 14b (see FIG. 3 (a)) are welded to the disk-shaped positive electrode current collector 14, and a large number of openings (FIG. The negative electrode current collector 15 having a disc shape (not shown) was welded to produce a spiral electrode body 10.

2. Lead Part Next, a drum-shaped cylindrical body 20 serving as a lead part for electrically connecting the positive electrode current collector 14 and the sealing body 17 is prepared. This drum-shaped cylindrical body 20 has a drum-shaped main body 21 having a concave central portion in the length direction.
And flanges 22 and 23 formed at the upper and lower ends of the main body. Wide portions 22a and narrow portions 22b are formed alternately on the upper flange portion 22, and wide portions 23a and narrow portions 23b are formed alternately on the lower flange portion 23. The wide portion 22a of the upper flange portion 22 and the narrow portion 23b of the lower flange portion 23 overlap each other with a space therebetween, and the narrow portion 22b of the upper flange portion 22 and the wide portion 23a of the lower flange portion 23.
And are arranged so as to overlap each other across a space. A small protrusion 22c is formed on the upper surface of the wide portion 22a of the upper flange 22. In addition, the thickness of the peripheral wall of the drum-shaped tubular body 20 is 0.3 mm, the minimum inner diameter is 14.8 mm, and the maximum outer diameter is 19.2 mm.

3. Nickel-hydrogen storage battery (1) Example 1 When assembling a nickel-hydrogen storage battery, first,
After the above-described drum-shaped tubular body 20 is placed on the positive electrode current collector 14, a welding electrode (not shown) is arranged on the outer peripheral portion of the narrow portion 22b of the upper end flange, and the width of the lower end flange is increased. Part 23a and current collector 1
4 was spot-welded. Thereafter, the electrode body 10 obtained by welding the drum-shaped cylindrical body 20 to the positive electrode current collector 14 is housed in a bottomed cylindrical battery case 16 in which nickel is plated on iron (the outer surface of the bottom surface is a negative electrode external terminal). did.

Next, a vibration isolating ring 18 was inserted into the upper inner peripheral side of the battery case 16, and a groove was formed on the outer peripheral side of the battery case 16 to form a concave portion 16 a at the upper end of the vibration isolating ring 18. Thereafter, an electrolyte composed of a 30% by mass aqueous solution of potassium hydroxide (KOH) was injected into the battery case 16. Then, the bottom surface of the sealing body 17 was arranged above the opening of the battery case 16 so as to be in contact with the upper end flange 22 of the tubular body 20. The sealing body 17 includes a lid 17a having a circular downward projection formed on the bottom surface, a positive electrode cap (positive electrode external terminal) 17b, and a spring 17c interposed between the lid 17a and the positive electrode cap 17b. And a valve plate 17d, and a gas vent hole is formed in the center of the lid 17a.

After the sealing member 17 is disposed as described above, one welding electrode W1 is disposed on the upper surface of the positive electrode cap (positive external terminal) 17a, and the other welding electrode is disposed on the lower surface of the bottom surface of the battery case 16 (negative external terminal). Was disposed. Thereafter, a distance between the pair of welding electrodes W1 and W2 is two.
While applying a pressure of × 10 ⁶ N / m ² , a voltage of 24 V was applied between these welding electrodes W1 and W2 in the discharge direction of the battery, and a current of 3 KA was applied for about 15 msec to perform an energization treatment. As a result of this energization processing, current concentrates on a contact portion between the bottom surface of the sealing body 17 and the small protrusion 22c formed on the wide portion 22a of the upper flange 22 of the drum-shaped tubular body 20, and the small projection 22c and the sealing body 17 was welded to the bottom surface to form a weld. At the same time, the contact portion between the lower surface of the negative electrode current collector 15 and the upper surface of the bottom surface (negative electrode external terminal) of the battery case 16 was welded to form a welded portion.

Next, an insulating gasket 19 is fitted around the periphery of the sealing body 17, and a pressing force is applied to the sealing body 17 using a press machine until the lower end of the insulating gasket 19 reaches the position of the recess 16a. Was pushed into the battery case 16. Thereafter, the opening edge of the battery case 16 was crimped inward to seal the battery, thereby producing a cylindrical nickel-hydrogen storage battery having a nominal capacity of 6.5 Ah. In addition, the main body 21 of the drum-shaped tubular body 20 was crushed by the pressing force at the time of sealing around the recessed central portion. The nickel-hydrogen storage battery of Example 1 thus manufactured was referred to as Battery A.

(2) Embodiment 2 First, after the above-mentioned drum-shaped tubular body 20 is placed on the positive electrode current collector 14, a welding electrode (not shown) is provided on the outer periphery of the narrow portion 22b of the upper flange 22. ), And the wide portion 2 of the lower end flange portion 23
3a and the current collector 14 were spot-welded. Thereafter, the electrode body 10 obtained by welding the drum-shaped cylindrical body 20 to the positive electrode current collector 14 is housed in a bottomed cylindrical battery case 16 in which nickel is plated on iron (the outer surface of the bottom surface is a negative electrode external terminal). did.

Then, a vibration isolating ring 18 was inserted into the upper inner peripheral side of the battery case 16, and a groove was formed on the outer peripheral side of the battery case 16 to form a concave portion 16 a at the upper end of the vibration isolating ring 18. Thereafter, an electrolyte composed of a 30% by mass aqueous solution of potassium hydroxide (KOH) was injected into the battery case 16. Then, the bottom surface of the sealing body 17 was arranged above the opening of the battery case 16 so as to be in contact with the upper end flange 22 of the tubular body 20. Note that the sealing member 17 is the same as that of the first embodiment described above.
Has the same configuration as that of the sealing body 17.

Next, an insulating gasket 19 is fitted around the periphery of the sealing body 17, and a pressing force is applied to the sealing body 17 using a press machine until the lower end of the insulating gasket 19 reaches the position of the recess 16a. Was pushed into the battery case 16. Thereafter, the opening edge of the battery case 16 was crimped inward to seal the battery. In addition, the main body 21 of the drum-shaped tubular body 20 was crushed by the pressurizing force at the time of sealing around the recessed central portion. Next, one welding electrode W1 was arranged on the upper surface of the positive electrode cap (positive electrode external terminal) 17a, and the other welding electrode W2 was arranged on the lower surface of the bottom surface of the battery case 16 (negative electrode external terminal).

Thereafter, the pair of welding electrodes W1, W
While applying a pressure of ² × 10 ⁶ N / m 2 between 2, by applying a voltage of the discharge direction 24V battery between these welding electrodes W1, W2, the energization operation to flow a current of 3KA about 15msec time gave. As a result of this energization processing, current concentrates on a contact portion between the bottom surface of the sealing body 17 and the small protrusion 22c formed on the wide portion 22a of the upper flange 22 of the drum-shaped tubular body 20, and the small projection 22c and the sealing body 17 was welded to the bottom surface to form a weld. At the same time, the contact portion between the lower surface of the negative electrode current collector 15 and the upper surface of the bottom surface (negative electrode external terminal) of the battery case 16 was welded to form a welded portion. As a result, a cylindrical nickel-hydrogen storage battery having a nominal capacity of 6.5 Ah was produced, and the battery B of Example 2 was obtained.

(3) Comparative Example As shown in FIG. 4, the positive electrode core exposed at the upper end face of the spiral electrode group manufactured in the same manner as in Example 1 described above has a number of openings, and a part of the openings. The disk-shaped positive electrode current collector 14a with the lead portion 14b extended was welded. On the other hand, a disk-shaped negative electrode current collector 15 having a large number of openings was welded to the negative electrode core exposed at the lower end surface of the spiral electrode group to produce a spiral electrode body. This electrode body is stored in the battery case 16,
The negative electrode current collector 15 is spot-welded to the inner bottom surface of the battery case 20 (note that in FIG. 4, it seems that there is no space for inserting a welding electrode at the center of the wound electrode body. Is a diagram schematically showing that there is actually a space for inserting a welding electrode). Thereafter, the vibration isolating ring 18 is inserted into the upper inner peripheral side of the battery case 16,
Groove processing was performed on the outer peripheral side of the battery case 16 to form a concave portion 16 a at the upper end of the vibration isolation ring 18.

Next, after the lead portion 14b extending from the positive electrode current collector 14a is bent vertically, the lead portion 14b is bent.
b was resistance welded to the bottom surface of the sealing body 17. Then
30% by mass of potassium hydroxide (KO)
H) After injecting an electrolytic solution consisting of an aqueous solution, the lead portion 14
b was bent, and a sealing body 17 having an insulating gasket 19 fitted on the periphery thereof was arranged at the opening of the battery case 16. Then, the battery was sealed by caulking the opening edge of the battery case 16 inward to produce a cylindrical nickel-hydrogen storage battery having a nominal capacity of 6.5 Ah. The nickel-hydrogen storage battery of the comparative example thus manufactured was designated as Battery X.

4. Battery Characteristics Test (1) Activation Using the batteries A and B of Examples 1 and 2 and the battery X of the comparative example produced as described above, room temperature (ambient temperature 25 ° C.)
After charging at a current value of 650 mA (0.1 C) for 8 hours, the battery was suspended for 1 hour, and then charged at 1300 mA (0.2 C).
A charge / discharge cycle was performed in which the battery was discharged at the current value of C) until the battery voltage reached 0.8 V, and the charge / discharge cycle was repeated 10 times to activate the battery.

(2) VI Characteristics Test Next, using the batteries A and B of Examples 1 and 2 and the battery X of the comparative example activated as described above, 1300 mA at room temperature (ambient temperature 25 ° C.) The battery in a state of being discharged until the battery voltage reaches 0.8 V at the current value of (2C) is 1300
The battery was charged at a current value of mA (0.2 C) for 3 hours. After a one-hour pause, the battery was discharged at a current value of 25 A for 30 seconds, and the battery voltage was measured 10 seconds after the start of discharge. Then, after charging the electric power corresponding to the discharged capacity, 50A, 7
The battery was discharged at a current value of 0 A and 100 A for 30 seconds, and the battery voltage was measured 10 seconds after the start of the discharge. The thus-obtained battery voltage 10 seconds after the start of discharge is set on the vertical axis, and each current value is set on the horizontal axis, with a VI straight line (VI characteristic).
Was obtained as shown in FIG.

As is clear from FIG. 5, the battery X of the comparative example
Examples 1 and 2 have a large slope of the VI line
It can be seen that the slopes of the VI straight lines of the batteries A and B are small. This indicates that the operating voltages of the batteries A and B of Examples 1 and 2 are all high and the internal resistance of the batteries is low.
This is because, in the batteries A and B of the first and second embodiments, the drum-shaped cylindrical body 20 serving as a lead portion has a large cross-sectional area in the current collecting direction and a short length (height) in the current collecting direction. It is considered that the internal resistance in the lead portion was reduced and high output characteristics were obtained.
Also, it is considered that the voltage drop was reduced due to the low internal resistance at the lead portion, and the operating voltage was also increased.

In the above-described embodiment, a voltage of 24 V is applied between the positive electrode cap (positive external terminal) 17a and the bottom surface of the battery case 16 (negative external terminal) in the battery discharge direction, and a current of 3 KA is applied. Was applied for about 15 msec for welding, but there was no correlation in the direction of the current applied to the battery, and similar results were obtained regardless of whether the battery was discharged or charged. Regarding the applied current value, the same effect was obtained at 300 A or more regardless of the size of the battery. In addition, as a power source of the welding current flowing between the battery case and the sealing body, a DC or AC power source can be used.

However, when an extremely large current is applied, the drum-shaped tubular body 20 melts even if the current is applied for a short time,
Since the upper limit value of the current value for fusing varies depending on the material and shape of the drum-shaped cylinder 20, the current value needs to be 300 A or more so that the drum-shaped cylinder 20 does not melt. Further, the same effect can be obtained if the application time is 0.25 msec or more. However, if the application is performed for a long time as long as 1 second, the drum-shaped tubular body 20 is melted, which is not preferable.

In the above-described embodiment, after the drum 20 is welded to the positive electrode current collector 14 side, the positive external terminal (positive cap) 17a and the negative external terminal (bottom surface of the battery case 16) are connected. During the welding, the drum-shaped cylindrical body 20 and the sealing body 17 are welded, but after the sealing body 17 and the drum-shaped cylindrical body 20 are welded, the positive electrode external terminal (positive electrode cap) 17 a A similar effect can be expected by welding a current between the negative electrode external terminal (the bottom surface of the battery case 16) and the positive electrode current collector 14 and the drum-shaped cylindrical body 20. In this case, it is necessary to provide a small projection on the lower surface of the wide portion 23a of the lower end flange portion 23 of the drum-shaped tubular body 20.

In the above-described embodiment, a current flows between the positive external terminal (positive cap) and the negative external terminal (bottom surface of the battery case) to weld the sealing body and the current collector. The example in which the negative electrode current collector and the inner bottom surface of the battery case are also welded at the same time has been described. A current may flow between the negative electrode external terminal (the bottom surface of the battery case) and the sealing body and the current collector may be welded. In this case, it is necessary to provide a space for inserting a welding electrode at the center of the spiral electrode body 10, and this space may be formed by a core trace space when the spiral electrode group is formed. Good.

Further, in the above-described embodiment,
Although an example has been described in which the sealing body is a positive terminal and the battery case is a negative terminal, the sealing body may be a negative terminal and the battery case may be a positive terminal. In this case, the positive electrode current collector is welded to the inner bottom surface of the battery case, and the bottom surface of the sealing body is welded to the negative electrode current collector via the drum 20. Furthermore, in the above-described embodiment, an example in which the present invention is applied to a nickel-hydrogen storage battery has been described. However, the present invention is not limited to a nickel-hydrogen storage battery, but may be applied to other storage batteries such as a nickel-cadmium storage battery. Clearly what you can do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a drum-shaped cylinder constituting a lead portion of the present invention is welded to a positive electrode current collector and a sealing body.

FIG. 2 is a cross-sectional view showing a state where an electrode body is inserted into a battery case and a drum-shaped tubular body and a sealing body are welded.

FIG. 3 is a view showing a main part of a state in which a drum-shaped cylindrical body is welded to an upper part of a positive electrode current collector of an electrode body, FIG. 3 (a) shows a top view thereof, and FIG. FIG. 3C is a cross-sectional view showing the AA cross section of FIG. 3A.

FIG. 4 is a cross-sectional view showing a storage battery of a conventional example (comparative example) and showing a state where a lead portion is welded to a sealing body.

FIG. 5 is a diagram showing a voltage (V) -current (I) characteristic of each battery.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Electrode body, 11 ... Positive electrode plate, 12 ... Negative electrode plate, 13 ... Separator, 14 ... Positive electrode collector, 15 ... Negative electrode collector, 16
... battery case (negative electrode external terminal), 16a ... groove, 17 ...
Sealing body, 17a: lid, 17b: positive electrode cap (positive electrode external terminal), 18: anti-vibration ring, 19: insulating gasket,
20: drum-shaped tubular body (lead part), 21: body part, 22, 2
3: Flange, 22a, 23a: Wide part, 22b, 23b ...
Narrow part, W1, W2 ... welding electrode

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takaaki Ikemachi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. F-term (reference) 5H022 AA04 BB11 CC12 CC13 CC21 5H028 AA01 BB03 BB05 CC05 CC12

Claims (11)

[Claims] 1. A battery case having an opening also serving as one terminal, a sealing body sealing the opening serving as a terminal of the other electrode, and at least one of a positive electrode and a negative electrode housed in the battery case. A battery comprising: an electrode body having a current collector connected to an end of the battery; wherein the sealing body and the current collector are each formed of a drum-shaped cylindrical body having a concave central portion in a longitudinal direction. A storage battery fixedly connected by a portion. 2. A method according to claim 1, wherein the upper and lower ends of the drum-shaped tubular body have a flange portion in which a wide portion and a narrow portion are alternately formed, and the wide portion of the upper flange portion and the narrow portion of the lower flange portion are formed. The storage battery according to claim 1, wherein the storage battery is overlapped with each other across a space, and the narrow portion of the upper end flange and the wide portion of the lower end flange are overlapped with each other across the space. . 3. The storage battery according to claim 2, wherein a small protrusion is formed on at least one of an upper surface of the wide portion of the upper end flange and a lower surface of the wide portion of the lower flange. 4. The storage battery according to claim 3, wherein the small protrusion is fixedly connected to a lower surface of the sealing body or an upper surface of the current collector. 5. The storage battery according to claim 1, wherein the drum-shaped tubular body is crushed by a pressing force about a central portion in a longitudinal direction thereof. 6. An electrode body having a current collector connected to at least one end of a positive electrode and a negative electrode is accommodated in a battery case having an opening serving also as a terminal of one electrode. A method for manufacturing a storage battery formed by sealing with a sealing body also serving as a terminal of a pole, wherein a lead portion composed of a drum-shaped cylindrical body having a concave central portion in a length direction is provided on an upper surface of the current collector or the sealing. A first welding step of welding to one of the lower surfaces of the body, an electrolyte injecting step of injecting an electrolytic solution into the battery case, an arranging step of arranging the sealing body in an opening of the battery case, A sealing step of sealing a sealing body with an opening of the battery case; and supplying a current between the battery case and the sealing body to cause the lead portion to be connected to either the lower surface of the sealing body or the upper surface of the current collector. A second welding step of welding to one side. Method of manufacturing a battery according to claim. 7. The sealing device according to claim 6, wherein in the sealing step, the sealing body is pressed against the drum-shaped cylinder to crush the center of the drum-shaped cylinder in the longitudinal direction. 3. The method for producing a storage battery according to claim 1. 8. An electrode body having a current collector connected to at least one end of a positive electrode and a negative electrode is accommodated in a battery case having an opening serving also as a terminal of one electrode. A method for manufacturing a storage battery formed by sealing with a sealing body also serving as a terminal of a pole, wherein a lead portion composed of a drum-shaped cylindrical body having a concave central portion in a length direction is provided on an upper surface of the current collector or the sealing. A first welding step of welding to one of the lower surfaces of the body, an electrolyte injecting step of injecting an electrolytic solution into the battery case, and the sealing body and the lead portion or the lead portion and the current collector An arranging step of arranging the sealing body in the opening of the battery case so as to be in contact with the battery case, and passing a current between the battery case and the sealing body to cause the lead portion to be positioned on the lower surface of the sealing body or Dissolve on one of the top surfaces of the current collector Second welding step and method for producing a battery, characterized in that a sealing step of sealing the sealing body into the opening of the battery case to. 9. The method according to claim 9, wherein in the second welding step, the sealing body is pressed against the drum-shaped cylinder to crush the center of the drum-shaped cylinder in the longitudinal direction. Item 9. The method for manufacturing a storage battery according to Item 8. 10. A drum-shaped tubular body having a flange portion in which wide portions and narrow portions are alternately formed at upper and lower ends thereof, and a wide-width portion and a lower-end flange portion of an upper-end flange portion of the drum-shaped tubular body. Are arranged so that the narrow portion of the drum-shaped tubular body overlaps with each other, and the narrow portion of the upper end flange portion and the wide portion of the lower end flange portion of the drum-shaped cylinder overlap with each other across the space. A welding electrode is arranged on the outer peripheral portion of the narrow portion of the upper flange portion,
The wide portion of the lower flange portion is welded to the upper surface of the current collector, or a welding electrode is disposed on the outer peripheral portion of the narrow portion of the lower flange portion, and the wide portion of the upper flange portion and the sealing body are disposed. The method for manufacturing a storage battery according to any one of claims 6 to 9, wherein the lower surface of the storage battery is welded. 11. A small projection is formed on at least one of an upper surface of a wide portion of the upper flange portion or a lower surface of a wide portion of the lower flange portion, and a welding current is concentrated on the small projection to form the small projection with the small projection. The method for manufacturing a storage battery according to claim 10, wherein the lower surface of the sealing body or the small protrusion is welded to the upper surface of the current collector.